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? 2009-2011 microchip technology inc. ds39960d pic18f87k22 family data sheet 64/80-pin, high-performance, 1-mbit enhanced flash microcontrollers with 12-bit a/d and nanowatt xlp technology downloaded from: http:///
ds39960d-page 2 ? 2009-2011 microchip technology inc. information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates. it is your responsibility to ensure that your application meets with your specifications. microchip makes no representations or warranties of any kind whether express or implied, written or oral, statutory or otherwise, related to the information, including but not limited to its condition, quality, performance, merchantability or fitness for purpose . microchip disclaims all liability arising from this information and its use. use of microchip devices in life support and/or safety applications is entirely at the buyers risk, and the buyer agrees to defend, indemnify and hold harmless microchip from any and all damages, claims, suits, or expenses resulting from such use. no licenses are conveyed, implicitly or otherwise, under any microchip intellectual property rights. trademarks the microchip name and logo, the microchip logo, dspic, k ee l oq , k ee l oq logo, mplab, pic, picmicro, picstart, pic 32 logo, rfpic and uni/o are registered trademarks of microchip technology incorporated in the u.s.a. and other countries. filterlab, hampshire, hi-tech c, linear active thermistor, mxdev, mxlab, seeval and the embedded control solutions company are registered trademarks of microchip technology incorporated in the u.s.a. analog-for-the-digital age, application maestro, chipkit, chipkit logo, codeguard, dspicdem, dspicdem.net, dspicworks, dsspeak, ecan, economonitor, fansense, hi-tide, in-circuit serial programming, icsp, mindi, miwi, mpasm, mplab certified logo, mplib, mplink, mtouch, omniscient code generation, picc, picc-18, picdem, picdem.net, pickit, pictail, real ice, rflab, select mode, total endurance, tsharc, uniwindriver, wiperlock and zena are trademarks of microchip technology incorporated in the u.s.a. and other countries. sqtp is a service mark of microchip technology incorporated in the u.s.a. all other trademarks mentioned herein are property of their respective companies. ? 2009-2011, microchip technology incorporated, printed in the u.s.a., all rights reserved. printed on recycled paper. isbn: 978-1-61341-272-5 note the following details of the code protection feature on microchip devices: microchip products meet the specification cont ained in their particular microchip data sheet. microchip believes that its family of products is one of the most secure families of its kind on the market today, when used i n the intended manner and under normal conditions. there are dishonest and possibly illegal methods used to breach the code protection feature. all of these methods, to our knowledge, require using the microchip products in a manner outside the operating specifications contained in microchips data sheets. most likely, the person doing so is engaged in theft of intellectual property. microchip is willing to work with the customer who is concerned about the integrity of their code. neither microchip nor any other semiconductor manufacturer c an guarantee the security of their code. code protection does not mean that we are guaranteeing the product as unbreakable. code protection is constantly evolving. we at microchip are co mmitted to continuously improvi ng the code protection features of our products. attempts to break microchips c ode protection feature may be a violation of the digital millennium copyright act. if such acts allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that act. microchip received iso/ts-16949:2002 certification for its worldwide headquarters, design and wafer fabrication facilities in chandler and tempe, arizona; gresham, oregon and design centers in california and india. the companys quality system processes and procedures are for its pic ? mcus and dspic ? dscs, k ee l oq ? code hopping devices, serial eeproms, microperipherals, nonvolatile memory an d analog products. in addition, microchips quality system for the design and manufacture of development systems is iso 9001:2000 certified. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 3 pic18f87k22 family low-power features: power-managed modes: - run: cpu on, peripherals on - idle: cpu off, peripherals on - sleep: cpu off, peripherals off two-speed oscillator start-up fail-safe clock monitor power-saving peripheral module disable (pmd) ultra low-power wake-up fast wake-up, 1 ? s typical low-power wdt, 300 na typical ultra low 50 na input leakage run mode currents down to 5.5 ? a, typical idle mode currents down to 1.7 ? a typical sleep mode currents down to very low 20 na, typical rtcc current downs to very low 700 na, typical special microcontroller features: operating voltage range: 1.8v to 5.5v on-chip 3.3v regulator operating speed up to 64 mhz up to 128 kbytes on-chip flash program memory data eeprom of 1,024 bytes 4k x 8 general purpose registers (sram) 10,000 erase/write cycle flash program memory, minimum 1,000,000 erase/write cycle data eeprom memory, typical flash retention: 40 years, minimum three internal oscillators: lf-intrc (31 khz), mf-intosc (500 khz) and hf-intosc (16 mhz) self-programmable under software control priority levels for interrupts 8 x 8 single-cycle hardware multiplier extended watchdog timer (wdt): - programmable period from 4 ms to 4,194s (about 70 minutes) in-circuit serial programming? (icsp?) via two pins in-circuit debug via two pins programmable: -bor -lvd device program memory data memory i/o 12-bit a/d (ch) ccp/ eccp (pwm) mssp eusart comparators timers 8/16-bit external bus ctmu rtcc flash (bytes) # single-word instructions sram (bytes) eeprom (bytes) spi master i 2 c? pic18f65k22 32k 16,383 2k 1k 53 16 5/3 2 y y 2 3 4/4 n y y pic18f66k22 64k 32,768 4k 1k 53 16 7/3 2y y 2 36/5 n yy pic18f67k22 128k 65,536 4k 1k 53 16 7/3 2y y 2 36/5 n yy pic18f85k22 32k 16,383 2k 1k 69 24 5/3 2 y y 2 3 4/4 y y y pic18f86k22 64k 32,768 4k 1k 69 24 7/3 2y y 2 36/5 y yy pic18f87k22 128k 65,536 4k 1k 69 24 7/3 2y y 2 36/5 y yy 64/80-pin, high-performance, 1- mbit enhanced flash mcus with 12-bit a/d and nanowatt xlp technology downloaded from: http:///
pic18f87k22 family ds39960d-page 4 ? 2009-2011 microchip technology inc. peripheral highlights: up to ten ccp/eccp modules: - up to seven capture/compare/pwm (ccp) modules - three enhanced capture/compare/pwm (eccp) modules up to eleven 8/16-bit timer/counter modules: - timer0 C 8/16-bit timer/counter with 8-bit programmable prescaler - timer1,3 C 16-bit timer/counter - timer2,4,6,8 C 8-bit timer/counter - timer5,7 C 16-bit timer/counter for 64k and 128k parts - timer10,12 C 8-bit timer/counter for 64k and 128k parts three analog comparators configurable reference clock output hardware real-time clock and calendar (rtcc) module with clock, calendar and alarm functions charge time measurement unit (ctmu): - capacitance measurement for mtouch? sensing solution - time measurement with 1 ns typical resolution - integrated temperature sensor high-current sink/source 25 ma/25 ma (portb and portc) up to four external interrupts two master synchronous serial port (mssp) modules: - 3/4-wire spi (supports all four spi modes) -i 2 c? master and slave modes two enhanced addressable usart modules: - lin/j2602 support - auto-baud detect (abd) 12-bit a/d converter with up to 24 channels: - auto-acquisition and sleep operation - differential input mode of operation integrated voltage reference downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 5 pic18f87k22 family pin diagrams C pic18f6xk22 12 3 4 5 6 7 8 9 10 11 12 13 14 3837 36 35 34 33 50 49 17 18 19 20 21 22 23 24 25 26 re2/cs /p2b/ccp10 (2) re3/p3c/ccp9 (2) /ref0 re4/p3b/ccp8re5/p1c/ccp7 re6/p1b/ccp6 re7/eccp2/p2a rd0/psp0/ctpls v dd v ss rd1/psp1/t5cki/t7grd2/psp2 rd3/psp3 rd4/psp4/sdo2 rd5/psp5/sdi2/sda2 rd6/psp6/sck2/scl2 rd7/psp7/ss2 re1/wr /p2c re0/rd /p2d rg0/eccp3/p3a rg1/tx2/ck2/an19/c3out rg2/rx2/dt2/an18/c3ina rg3/ccp4/an17/p3d/c3inb mclr /rg5 rg4/rtcc/t7cki (2) /t5g/ccp5/an16/p1d/c3inc v ss v ddcore /v cap rf7/an5/ss1 rf6/an11/c1ina rf5/an10/cv ref /c1inb rf4/an9/c2ina rf3/an8/c2inb/ctmui rf2/an7/c1out rb0/int0/flt0 rb1/int1 rb2/int2/cted1 rb3/int3/cted2/eccp2 (1) /pa2 rb4/kbi0 rb5/kbi1/t3cki/t1g rb6/kbi2/pgc v ss osc2/clko/ra6osc1/clki/ra7 v dd rb7/kbi3/pgdrc4/sdi1/sda1 rc3/sck1/scl1 rc2/eccp1/p1a envreg rf1/an6/c2out/ctdin av dd av ss ra3/an3/v ref + ra2/an2/v ref - ra1/an1 ra0/an0/ulpwu v ss v dd ra4/t0cki ra5/an4/t1cki/t3g/hlvdin rc1/sosci/eccp2 (1) /p2a rc0/sosco/sclki rc7/rx1/dt1 rc6/tx1/ck1 rc5/sdo1 1516 31 4039 27 28 29 30 32 4847 46 45 44 43 42 41 54 53 52 51 58 57 56 55 60 59 64 63 62 61 64-pin tqfp, qfn pic18f65k22 pic18f66k22 pic18f67k22 note 1: the eccp2 pin placement depends on the ccp2mx conf iguration bit setting and whether the device is in microcontroller or extended microcontroller mode. 2: not available on the pic18f65k22 and pic18f85k22 devices. downloaded from: http:///
pic18f87k22 family ds39960d-page 6 ? 2009-2011 microchip technology inc. pin diagrams C pic18f8xk22 34 5 6 7 8 9 10 11 12 1314 15 16 4847 46 45 44 43 42 41 40 39 64 63 62 61 21 22 23 24 25 26 27 28 29 30 31 32 re2/p2b/ccp10 (2) /cs /ad10 re4/p3b/ccp8 (3) /ad12 re5/p1c/ccp7 (3) /ad13 re6/p1b/ccp6 (3) /ad14 re7/eccp2/p2a/ad15rd0/psp0/ctpls/ad0 v dd v ss rd1/t5cki/t7g/psp1/ad1 rd2/psp2/ad2 rd3/psp3/ad3 rd4/sdo2/psp4/ad4 rd5/sdi2/sda2/psp5/ad5 rd6/sck2/scl2/psp6/ad6 rd7/ss2 /psp7/ad7 re1/p2c/wr /ad9 re0/p2d/rd /ad8 rg0/eccp3/p3a rg1/tx2/ck2/an19/c3out rg2/rx2/dt2/an18/c3ina rg3/ccp4/an17/p3d/c3inb mclr /rg5 rg4/rtcc/t7cki (2) /t5g/ccp5/an16/p1d/c3inc v ss v ddcore /v cap rf7/an5/ss1 rb0/int0/flt0 rb1/int1 rb2/int2/cted1 rb3/int3/cted2/eccp2 (1) /p2a rb4/kbi0rb5/kbi1/t3cki/t1g rb6/kbi2/pgc v ss osc2/clko/ra6osc1/clki/ra7 v dd rb7/kbi3/pgdrc4/sdi1/sda1 rc3/sck1/scl1 rc2/eccp1/p1a envreg rf1/an6/c2out/ctdin av dd av ss ra3/an3/v ref + ra2/an2/v ref - ra1/an1 ra0/an0/ulpwu v ss v dd ra4/t0cki ra5/an4/t1cki/t3g/hlvdin rc1/sosc/eccp2/p2a rc0/sosco/sckli rc7/rx1/dt1 rc6/tx1/ck1 rc5/sdo1 rj0/alerj1/oe rh1/an22/a17rh0/an23/a16 12 rh2/an21/a18rh3/an20/a19 1718 rh7/ccp6 (3) /p1b/an15 rh6/ccp7 (3) /p1c/an14/c1inc rh5/ccp8 (3) /p3b/an13/c2ind rh4/ccp9 (2,3) /p3c/an12/c2inc rj5/ce rj4/ba0 37 rj7/ub rj6/lb 5049 rj2/wrl rj3/wrh 19 20 33 34 35 36 38 5857 56 55 54 53 52 51 6059 68 67 66 65 72 71 70 69 74 73 78 77 76 75 79 80 80-pin tqfp rf5/an10/c1inb rf4/an9/c2ina rf3/an8/c2inb/ctmui rf2/an7/c1out rf6/an11/c1ina pic18f85k22 pic18f86k22 pic18f87k22 note 1: the eccp2 pin placement depends on the ccp2mx co nfiguration bit setting and whether the device is in microcontroller or extended microcontroller mode. 2: not available on the pic18f65k22 and pic18f85k22 devices. 3: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). re3/p3c/ccp9 (2,3) / ref0/ad11 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 7 pic18f87k22 family table of contents 1.0 device overview ....................................................... ...................................................... ............................................................. 9 2.0 guidelines for getting started with pic18fxxkxx microcontroll ers ............................................................ ............................. 37 3.0 oscillator configurations ..................................... .............................................................. ......................................................... 43 4.0 power-managed modes ............................................ ................................................... .......... .................................................... 57 5.0 reset .......................................................................................... ................................................................................................ 73 6.0 memory organization .......................................... ................................................... ............ ........................................................ 87 7.0 flash program memory.................................................................. ...................................... .................................................... 111 8.0 external memory bus ................................................................. .............................................................................................. 121 9.0 data eeprom memory ..................................................................... ..................................... ................................................. 133 10.0 8 x 8 hardware multiplier.................................................... .............................................. ........................................................ 139 11.0 interrupts .................................................................................. ................................................................................................ 141 12.0 i/o ports ....................................................................................... ........................... ................................................................. 165 13.0 timer0 module .............................................. ................................................... ............. ........................................................... 193 14.0 timer1 module .............................................. ................................................... ............. ........................................................... 197 15.0 timer2 module .............................................. ................................................... ............. ........................................................... 209 16.0 timer3/5/7 modules............................................ ................................................... .......... ......................................................... 211 17.0 timer4/6/8/10/12 modules............................................... .................................................... ..................................................... 223 18.0 real-time clock and calendar (rtcc)...................................... .................................................. ........................................... 227 19.0 capture/compare/pwm (ccp) modules ....................................... ................................................... ....................................... 245 20.0 enhanced capture/compare/pwm (eccp) module.................................... ............................................. ............................... 259 21.0 master synchronous serial port (mssp) module ................................. .............................................. ..................................... 281 22.0 enhanced universal synchronous asynchronous receiver transmitter (eusart) ....................................... ........... ............. 327 23.0 12-bit analog-to-digital converter (a/d) module ................................ ............................................ ......................................... 351 24.0 comparator module.......................................... ................................................... ............. ........................................................ 367 25.0 comparator voltage reference module.................................. ................................................... ... ........................................... 375 26.0 high/low-voltage detect (hlvd)......................................... ................................................... . ................................................ 379 27.0 charge time measurement unit (ctmu) .......................................... .............................................. ........................................ 385 28.0 special features of the cpu...................................................... .......................................... .................................................... 403 29.0 instruction set summary ........................................................ ............................................ ...................................................... 431 30.0 development support............................................ ................................................... ......... ....................................................... 481 31.0 electrical characteristics ........................................................ ......................................... ......................................................... 485 32.0 packaging information..................................................... ................................................. ........................................................ 525 appendix a: revision history.......................................... ................................................... ...... .......................................................... 533 appendix b: migration from pic18f87j11 and pic18f8722 to pic18f87k22.......................... ................................. ..................... 534 index ................................................. ................................................... ...................... ........................................................................ 535 the microchip web site ....................................................................... .................................. ............................................................ 547 customer change notification service ....................................... ................................................... . ................................................... 547 customer support............................................... ................................................... ............. ............................................................... 547 reader response ................................................. ................................................... ............ .............................................................. 548 product identification system ................................................. ..................................................................................................... ...... 549 downloaded from: http:///
pic18f87k22 family ds39960d-page 8 ? 2009-2011 microchip technology inc. to our valued customers it is our intention to provide our valued customers with the be st documentation possible to ensure successful use of your micro chip products. to this end, we will continue to improve our publications to better suit your needs. our publications will be refined and enhanced as new volumes and updates are introduced. if you have any questions or comments regardi ng this publication, please contact the marketing communications department via e-mail at docerrors@microchip.com or fax the reader response form in the back of this data sheet to (480) 792-4150. we welcome your feedback. most current data sheet to obtain the most up-to-date version of this data s heet, please register at our worldwide web site at: http://www.microchip.com you can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page . the last character of the literature number is the vers ion number, (e.g., ds30000a is version a of document ds30000). errata an errata sheet, describing minor operational differences fr om the data sheet and recommended workarounds, may exist for curren t devices. as device/documentation issues become known to us, we will publish an errata sheet. the errata will specify the revisi on of silicon and revision of document to which it applies. to determine if an errata sheet exists for a particular device, please check with one of the following: microchips worldwide web site; http://www.microchip.com your local microchip sales office (see last page) when contacting a sales office, please specify which device, re vision of silicon and data sheet (include literature number) you are using. customer notification system register on our web site at www.microchip.com to receive the most current information on all of our products. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 9 pic18f87k22 family 1.0 device overview this document contains device-specific information for the following devices: this family combines the traditional advantages of all pic18 microcontrollers C namely, high computational performance and a rich feature set C with an extremely competitive price point. these features make the pic18f87k22 family a logical choice for many high-performance applications where price is a primary consideration. 1.1 core features 1.1.1 nanowatt technology all of the devices in the pic18f87k22 family incorpo- rate a range of features that can significantly reduce power consumption during operation. key items include: alternate run modes: by clocking the controller from the timer1 source or the internal rc oscilla- tor, power consumption during code execution can be reduced. multiple idle modes: the controller can also run with its cpu core disabled but the peripherals still active. in these states, power consumption can be reduced even further. on-the-fly mode switching: the power-managed modes are invoked by user code during operation, allowing the user to incorporate power-saving ideas into their applications software design. nanowatt xlp: an extra low-power sleep, bor, rtcc and watchdog timer 1.1.2 oscillator options and features all of the devices in the pic18f87k22 family offer different oscillator options, allowing users a range of choices in developing application hardware. these include: external resistor/capacitor (rc); ra6 available external resistor/capacitor with clock out (rcio) three external clock modes: - external clock (ec); ra6 available - external clock with clock out (ecio) - external crystal (xt, hs, lp) a phase lock loop (pll) frequency multiplier, available to the external oscillator modes, which allows clock speeds of up to 64 mhz. pll can also be used with the internal oscillator. an internal oscillator block that provides a 16 mhz clock (2% accuracy) and an intrc source (approximately 31 khz, stable over temperature and v dd ) - operates as hf-intosc or mf-intosc when block selected for 16 mhz or 500 khz - frees the two oscillator pins for use as additional general purpose i/o the internal oscillator block provides a stable reference source that gives the family additional features for robust operation: fail-safe clock monitor: this option constantly monitors the main clock source against a reference signal provided by the internal oscillator. if a clock failure occurs, the controller is switched to the internal oscillator, allowing for continued low-speed operation or a safe application shutdown. two-speed start-up: this option allows the internal oscillator to serve as the clock source from power-on reset, or wake-up from sleep mode, until the primary clock source is available. 1.1.3 memory options the pic18f87k22 family provides ample room for application code, from 32 kbytes to 128 kbytes of code space. the flash cells for program memory are rated to last up to 10,000 erase/write cycles. data retention without refresh is conservatively estimated to be greater than 40 years. the flash program memory is readable and writable. during normal operation, the pic18f87k22 family also provides plenty of room for dynamic application data with up to 3,862 bytes of data ram. 1.1.4 external memory bus should 128 kbytes of memory be inadequate for an application, the 80-pin members of the pic18f87k22 family have an external memory bus (emb) enabling the controllers internal program counter to address a memory space of up to 2 mbytes. this is a level of data access that few 8-bit devices can claim and enables: using combinations of on-chip and external memory of up to 2 mbytes using external flash memory for reprogrammable application code or large data tables using external ram devices for storing large amounts of variable data 1.1.5 extended instruction set the pic18f87k22 family implements the optional extension to the pic18 instruction set, adding eight new instructions and an indexed addressing mode. enabled as a device configuration option, the extension has been specifically designed to optimize re-entrant application code originally developed in high-level languages, such as c. pic18f65k22 pic18f85k22 pic18f66k22 pic18f86k22 pic18f67k22 pic18f87k22 downloaded from: http:///
pic18f87k22 family ds39960d-page 10 ? 2009-2011 microchip technology inc. 1.1.6 easy migration all devices share the same rich set of peripherals except that the devices with 32 kbytes of program memory (pic18f65k22 and pic18f85k22) have two less ccps and three less timers. this provides a smooth migration path within the device family as applications evolve and grow. the consistent pinout scheme, used throughout the entire family, also aids in migrating to the next larger device. this is true when moving between the 64-pin members, between the 80-pin members, or even jumping from 64-pin to 80-pin devices. all of the devices in the family share the same rich set of peripherals, except for those with 32 kbytes of program memory (pic18f65k22 and pic18f85k22). those devices have two less ccps and three less timers. the pic18f87k22 family is also largely pin compatible with other pic18 families, such as the pic18f8720 and pic18f8722 and the pic18f85j11. this allows a new dimension to the evolution of applications, allowing developers to select different price points within microchips pic18 portfolio, while maintaining a similar feature set. 1.2 other special features communications: the pic18f87k22 family incorporates a range of serial communication peripherals, including two enhanced usarts (eusart) that support lin/j2602, and two master ssp modules, capable of both spi and i 2 c? (master and slave) modes of operation. ccp modules: pic18f87k22 family devices incorporate up to seven capture/compare/pwm (ccp) modules. up to six different time bases can be used to perform several different operations at once. eccp modules: the pic18f87k22 family has three enhanced ccp (eccp) modules to maximize flexibility in control applications: - up to eight different time bases for performing several different operations at once - up to four pwm outputs for each module, for a total of 12 pwms - other beneficial features, such as polarity selection, programmable dead time, auto-shutdown and restart, and half-bridge and full-bridge output modes 12-bit a/d converter: the pic18f87k22 family has differential adc. it incorporates program- mable acquisition time, allowing for a channel to be selected and a conversion to be initiated without waiting for a sampling period, and thus, reducing code overhead. charge time measurement unit (ctmu): the ctmu is a flexible analog module that provides accurate differential time measurement between pulse sources, as well as asynchronous pulse generation. together with other on-chip analog modules, the ctmu can precisely measure time, measure capacitance or relative changes in capacitance, or generate output pulses that are independent of the system clock. lp watchdog timer (wdt): this enhanced version incorporates a 22-bit prescaler, allowing an extended time-out range that is stable across operating voltage and temperature. see section 31.0 electrical characteristics for time-out periods. real-time clock and calendar module (rtcc): the rtcc module is intended for appli- cations requiring that accurate time be maintained for extended periods of time with minimum to no intervention from the cpu. the module is a 100-year clock and calendar with automatic leap year detection. the range of the clock is from 00:00:00 (midnight) on january 1, 2000 to 23:59:59 on december 31, 2099. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 11 pic18f87k22 family 1.3 details on individual family members devices in the pic18f87k22 family are available in 64-pin and 80-pin packages. block diagrams for the two groups are shown in figure 1-1 and figure 1-2 . the devices are differentiated from each other in these ways: flash program memory: - pic18fx5k22 (pic18f65k22 and pic18f85k22) C 32 kbytes - pic18fx6k22 (pic18f66k22 and pic18f86k22) C 64 kbytes - pic18fx7k22 (pic18f67k22 and pic18f87k22) C 128 kbytes data ram: - all devices except pic18fx5k22 C 4 kbytes - pic18fx5k22 C 2 kbytes i/o ports: - pic18f6xk22 (64-pin devices) C 7 bidirectional ports - pic18f8xk22 (80-pin devices) C 9 bidirectional ports ccp modules: - pic18fx5k22 (pic18f65k22 and pic18f85k22) C 5 ccp modules - pic18fx6k22 and pic18fx7k22 (pic18f66k22, pic18f86k22, pic18f67k22, and pic18f87k22) C 7 ccp modules timer modules: - pic18fx5k22 (pic18f65k22 and pic18f85k22) C four 8-bit timer/counters and four 16-bit timer/counters - pic18fx6k22 and pic18fx7k22 (pic18f66k22, pic18f86k22, pic18f67k22, and pic18f87k22) C six 8-bit timer/counters and five 16-bit timer/counters a/d channels: - pic18f6xk22 (64-pin devices) C 24 channels - pic18f8xk22 (80-pin devices) C 16 channels all other features for devices in this family are identical. these are summarized in ta b l e 1 - 1 and tab l e 1 - 2 . the pinouts for all devices are listed in tab l e 1 - 3 and table 1-4 . downloaded from: http:///
pic18f87k22 family ds39960d-page 12 ? 2009-2011 microchip technology inc. table 1-1: device features for the pic18f6xk22 (64-pin devices) table 1-2: device features for the pic18f8xk22 (80-pin devices) features pic18f65k22 pic18f66k22 pic18f67k22 operating frequency dc C 64 mhz program memory (bytes) 32k 64k 128k program memory (instructions) 16,384 32,768 65,536 data memory (bytes) 2k 4k 4k interrupt sources 42 48 i/o ports ports a, b, c, d, e, f, g parallel communications parallel slave port (psp) timers 8 11 comparators 3 ctmu yes rtcc yes capture/compare/pwm (ccp) modules 5 7 7 enhanced ccp (eccp) modules 3 serial communications two mssps and two enhanced usarts (eusart) 12-bit analog-to-digital module 16 input channels resets (and delays) por, bor, reset instruction, stack full, stack underflow, mclr , wdt (pwrt, ost) instruction set 75 instructions, 83 with extended instruction set enabled packages 64-pin qfn, 64-pin tqfp features pic18f85k22 pic18f86k22 pic18f87k22 operating frequency dc C 64 mhz program memory (bytes) 32k 64k 128k (up to 2 mbytes with extended memory) program memory (instructions) 16,384 32,768 65,536 data memory (bytes) 2k 4k 4k interrupt sources 42 48 i/o ports ports a, b, c, d, e, f, g, h, j parallel communications parallel slave port (psp) timers 8 11 comparators 3 ctmu yes rtcc yes capture/compare/pwm (ccp) modules 5 7 7 enhanced ccp (eccp) modules 3 serial communications two mssps and 2 enhanced usarts (eusart) 12-bit analog-to-digital module 24 input channels resets (and delays) por, bor, reset instruction, stack full, stack underflow, mclr , wdt (pwrt, ost) instruction set 75 instructions, 83 with extended instruction set enabled packages 80-pin tqfp downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 13 pic18f87k22 family figure 1-1: pic18f6xk22 ( 64-pin) block diagram instruction decode and control porta data latch data memory (2/4 kbytes) address latch data address<12> 12 access bsr fsr0 fsr1 fsr2 inc/dec logic address 4 12 4 pch pcl pclath 8 31-level stack program counter prodl prodh 8 x 8 multiply 8 bitop 8 8 alu<8> address latch program memory data latch 20 8 8 table pointer<21> inc/dec logic 21 8 data bus<8> table latch 8 ir 12 3 pclatu pcu note 1: see table 1-3 for i/o port pin descriptions. 2: ra6 and ra7 are only available as digital i/o in se lect oscillator modes. for more information, see section 3.0 oscillator configurations . 3: unimplemented on the pic18f65k22. eusart1 comparator mssp1/2 3/5/7 (3) 2/4/6/8/10 (3) /12 (3) ctmu timer1 adc 12-bit w instruction bus <16> stkptr bank 8 state machine control signals decode 8 8 eusart2 rom latch portc portd porte portf portg ra0:ra7 (1,2) rc0:rc7 (1) rd0:rd7 (1) re0: re7 (1) rf1:rf7 (1) rg0:rg5 (1) portb rb0:rb7 (1) osc1/clki osc2/clko v dd , timing generation v ss mclr power-up timer oscillator start-up timer power-on reset watchdog timer bor and lvd precision reference band gap intrc oscillator regulator voltage v ddcore /v cap envreg 16 mhz oscillator timer0 4/5/6/7/8/9 (3) /10 (3) rtcc timer timer 1/2/3 ccp eccp 1/2/3 downloaded from: http:///
pic18f87k22 family ds39960d-page 14 ? 2009-2011 microchip technology inc. figure 1-2: pic18f8xk22 ( 80-pin) block diagram instruction decode and control data latch address latch data address<12> 12 access bsr fsr0 fsr1 fsr2 inc/dec logic address 41 24 pch pcl pclath 8 31-level stack program counter prodl prodh 8 x 8 multiply 8 bitop 8 8 alu<8> address latch program memory data latch 20 8 8 table pointer<21> inc/dec logic 21 8 data bus<8> table latch 8 ir 12 3 pclatu pcu w instruction bus <16> stkptr bank 8 state machine control signals decode 8 8 rom latch osc1/clki osc2/clko v dd , v ss mclr power-up timer oscillator start-up timer power-on reset watchdog timer precision reference band gap regulator voltage v ddcore /v cap envreg porta portc portd porte portf portg ra0:ra7 (1,2) rc0:rc7 (1) rd0:rd7 (1) rf1:rf7 (1) rg0:rg5 (1) portb rb0:rb7 (1) porth rh0:rh7 (1) portj rj0:rj7 (1) note 1: see table 1-3 for i/o port pin descriptions. 2: ra6 and ra7 are only available as digital i/o in select oscillator modes. see section 3.0 oscillator configurations for more information. 3: unimplemented on the pic18f85k22. timing generation intrc oscillator 16 mhz oscillator re0:re7 (1) bor and lvd data memory (2/4 kbytes) eusart1 comparator mssp1/2 3/5/7 (3) 2/4/6/8/10 (3) /12 (3) ctmu timer1 adc 12-bit eusart2 timer0 4/5/6/7/8/9 (3) /10 (3) rtcc timer timer 1/2/3 ccp eccp 1/2/3 system bus interface ad15:0, a19:16 (multiplexed with portd, porte and porth) downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 15 pic18f87k22 family table 1-3: pic18f6xk22 pi nout i/o descriptions pin name pin number pin type buffer type description qfn/tqfp mclr /rg5 mclr rg5 7 ii stst master clear (input) or programming voltage (input). this pin is an active-low reset to the device. general purpose, input only pin. osc1/clki/ra7 osc1 clki ra7 39 ii i/o cmos cmos ttl oscillator crystal or external clock input. oscillator crystal input. external clock source input. always associated with pin function, osc1. (see related osc1/clki, osc2/clko pins.) general purpose i/o pin. osc2/clko/ra6 osc2 clko ra6 40 oo i/o ttl oscillator crystal or clock output. oscillator crystal output. connects to crystal or resonator in crystal oscillator mode. in certain oscillator modes, osc2 pin outputs clko, which has 1/4 the frequency of osc1 and denotes the instruction cycle rate. general purpose i/o pin. legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
pic18f87k22 family ds39960d-page 16 ? 2009-2011 microchip technology inc. porta is a bidirectional i/o port. ra0/an0/ulpwu ra0 an0 ulpwu 24 i/o ii ttl analog analog digital i/o. analog input 0. ultra low-power wake-up input. ra1/an1 ra1 an1 23 i/o i ttl analog digital i/o. analog input 1. ra2/an2/v ref - ra2 an2 v ref - 22 i/o ii ttl analog analog digital i/o. analog input 2. a/d reference voltage (low) input. ra3/an3/v ref + ra3 an3 v ref + 21 i/o ii ttl analog analog digital i/o. analog input 3. a/d reference voltage (high) input. ra4/t0cki ra4 t0cki 28 i/o i stst digital i/o. timer0 external clock input. ra5/an4/t1cki/t3g/ hlvdin ra5 an4 t1cki t3g hlvdin 27 i/o ii i i ttl analog stst analog digital i/o. analog input 4. timer1 clock input. timer3 external clock gate input. high/low-voltage detect input. ra6 see the osc2/clko/ra6 pin. ra7 see the osc1/clki/ra7 pin. table 1-3: pic18f6xk2 2 pinout i/o descriptions (continued) pin name pin number pin type buffer type description qfn/tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 17 pic18f87k22 family portb is a bidirectional i/o port. portb can be software programmed for internal weak pull-ups on all inputs. rb0/int0/flto rb0 int0 flt0 48 i/o ii ttl stst digital i/o. external interrupt 0. enhanced pwm fault input for eccp1/2/3. rb1/int1 rb1 int1 47 i/o i ttl st digital i/o. external interrupt 1. rb2/int2/cted1 rb2 int2 cted1 46 i/o ii ttl stst digital i/o. external interrupt 2. ctmu edge 1 input. rb3/int3/cted2/ eccp2/p2a rb3 int3 cted2 eccp2 p2a 45 i/o ii i/o o ttl stst st digital i/o. external interrupt 3. ctmu edge 2 input. capture 2 input/compare 2 output/pwm2. enhanced pwm2 output a. rb4/kbi0 rb4 kbi0 44 i/o i ttlttl digital i/o. interrupt-on-change pin. rb5/kbi1/t3cki/t1g rb5 kbi1 t3cki t1g 43 i/o ii i ttlttl stst digital i/o. interrupt-on-change pin. timer3 clock input. timer1 external clock gate input. rb6/kbi2/pgc rb6 kbi2 pgc 42 i/o i i/o ttlttl st digital i/o. interrupt-on-change pin. in-circuit debugger and icsp? programming clock pin. rb7/kbi3/pgd rb7 kbi3 pgd 37 i/o i i/o ttlttl st digital i/o. interrupt-on-change pin. in-circuit debugger and icsp programming data pin. table 1-3: pic18f6xk2 2 pinout i/o descri ptions (continued) pin name pin number pin type buffer type description qfn/tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
pic18f87k22 family ds39960d-page 18 ? 2009-2011 microchip technology inc. portc is a bidirectional i/o port. rc0/sosco/sclki rc0 sosco sclki 30 i/o o i st st digital i/o. sosc oscillator output. digital sosc input. rc1/sosci/eccp2/p2a rc1 sosci eccp2 (1) p2a 29 i/o i i/o o st cmos st digital i/o. sosc oscillator input. capture 2 input/compare 2 output/pwm2 output. enhanced pwm2 output a. rc2/eccp1/p1a rc2 eccp1 p1a 33 i/o i/o o stst digital i/o. capture 1 input/compare 1 output/pwm1 output. enhanced pwm1 output a. rc3/sck1/scl1 rc3 sck1 scl1 (4) 34 i/o i/o i/o stst i 2 c digital i/o. synchronous serial clock input/output for spi mode. synchronous serial clock input/output for i 2 c? mode. rc4/sdi1/sda1 rc4 sdi1 sda1 (4) 35 i/o i i/o stst i 2 c digital i/o. spi data in. i 2 c data i/o. rc5/sdo1 rc5 sdo1 36 i/o o st digital i/o. spi data out. rc6/tx1/ck1 rc6 tx1 ck1 31 i/o o i/o st st digital i/o. eusart asynchronous transmit. eusart synchronous clock (see related rx1/dt1). rc7/rx1/dt1 rc7 rx1 dt1 32 i/o i i/o stst st digital i/o. eusart asynchronous receive. eusart synchronous data (see related tx1/ck1). table 1-3: pic18f6xk2 2 pinout i/o descriptions (continued) pin name pin number pin type buffer type description qfn/tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 19 pic18f87k22 family portd is a bidirectional i/o port. rd0/psp0/ctpls rd0 psp0 ctpls 58 i/o i/o o st ttl digital i/o. parallel slave port data. ctmu pulse generator output. rd1/psp1/t5cki/t7g rd1 psp1 t5cki t7g 55 i/o i/o ii st ttl stst digital i/o. parallel slave port. timer5 clock input. timer7 external clock gate input. rd2/psp2 rd2 psp2 54 i/o o st ttl digital i/o. parallel slave port. rd3/psp3 rd3 psp3 53 i/o i/o st ttl digital i/o. parallel slave port. rd4/psp4/sdo2 rd4 psp4 sdo2 52 i/o i/o o st ttl digital i/o. parallel slave port. spi data out. rd5/psp5/sdi2/sda2 rd5 psp5 sdi2 sda2 51 i/o i/o i i/o st ttl st i 2 c digital i/o. parallel slave port. spi data in. i 2 c? data i/o. rd6/psp6/sck2/scl2 rd6 psp6 sck2 scl2 (4) 50 i/o i/o i/o i/o st ttl st i 2 c digital i/o. parallel slave port. synchronous serial clock. synchronous serial clock i/o for i 2 c mode. rd7/psp7/ss2 rd7 psp7 ss2 49 i/o i/o i st ttlttl digital i/o. parallel slave port. spi slave select input. table 1-3: pic18f6xk2 2 pinout i/o descri ptions (continued) pin name pin number pin type buffer type description qfn/tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
pic18f87k22 family ds39960d-page 20 ? 2009-2011 microchip technology inc. porte is a bidirectional i/o port. re0/rd /p2d re0 rd p2d 2 i/o i o st ttl digital i/o. parallel slave port read strobe. eecp2 pwm output d. re1/wr /p2c re1 wr p2c 1 i/o i o st ttl digital i/o. parallel slave port write strobe. eccp2 pwm output c. re2/cs /p2b/ccp10 re2 cs p2b ccp10 ( 3 ) 64 i/o i o i/o st ttl s/t digital i/o. parallel slave port chip select. eccp2 pwm output b. capture 10 input/compare 10 output/pwm10 output. re3/p3c/ccp9/refo re3 p3c ccp9 ( 3 , 4 ) refo 63 i/o o i/o o st s/t digital i/o. eccp3 pwm output c. capture 9 input/compare 9 output/pwm9 output. reference clock out. re4/p3b/ccp8 re4 p3b ccp8 ( 4 ) 62 i/o o i/o st s/t digital i/o. eccp3 pwm output b. capture 8 input/compare 8 output/pwm8 output. re5/p1c/ccp7 re5 p1c ccp7 ( 4 ) 61 i/o o i/o st s/t digital i/o. eccp1 pwm output c. capture 7 input/compare 7 output/pwm7 output. re6/p1b/ccp6 re6 p1b ccp6 ( 4 60 i/o o i/o st s/t digital i/o. eccp1 pwm output b. capture 6 input/compare 6 output/pwm6 output. re7/eccp2/p2a re7 eccp2 ( 2 ) p2a 59 i/o i/o o stst digital i/o. capture 2 input/compare 2 output/pwm2 output. eccp2 pwm output a. table 1-3: pic18f6xk2 2 pinout i/o descriptions (continued) pin name pin number pin type buffer type description qfn/tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 21 pic18f87k22 family portf is a bidirectional i/o port. rf1/an6/c2out/ctdin rf1 an6 c2out ctdin 17 i/o i o i st analog st digital i/o. analog input 6. comparator 2 output. ctmu pulse delay input. rf2/an7/c1out rf2 an7 c1out 16 i/o i o st analog digital i/o. analog input 7. comparator 1 output. rf3/an8/c2inb/ctmui rf3 an8 c2inb ctmui 15 i/o ii o st analog analog digital i/o. analog input 8. comparator 2 input b. ctmu pulse generator charger for the c2inb comparator input. rf4/an9/c2ina rf4 an9 c2ina 14 i/o ii st analog analog digital i/o. analog input 9. comparator 2 input a. rf5/an10/cv ref /c1inb rf5 an10 cv ref c1inb 13 i/o i o i st analog analog analog digital i/o. analog input 10. comparator reference voltage output. comparator 1 input b. rf6/an11/c1ina rf6 an11 c1ina 12 i/o ii st analog analog digital i/o. analog input 11. comparator 1 input a. rf7/an5/ss1 rf7 an5 ss1 11 i/o o i st analog ttl digital i/o. analog input 5. spi1 slave select input. table 1-3: pic18f6xk2 2 pinout i/o descri ptions (continued) pin name pin number pin type buffer type description qfn/tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
pic18f87k22 family ds39960d-page 22 ? 2009-2011 microchip technology inc. portg is a bidirectional i/o port. rg0/eccp3/p3a rg0 eccp3 p3a 3 i/o i/o o stst digital i/o. capture 3 input/compare 3 output/pwm3 output. eccp3 pwm output a. rg1/tx2/ck2/an19/ c3out rg1 tx2 ck2 an19 c3out 4 i/o o i/o i o st st analog digital i/o. eusart asynchronous transmit. eusart synchronous clock (see related rx2/dt2). analog input 19. comparator 3 output. rg2/rx2/dt2/an18/ c3ina rg2 rx2 dt2 an18 c3ina 5 i/o i i/o ii stst st analog analog digital i/o. eusart asynchronous receive. eusart synchronous data (see related tx2/ck2). analog input 18. comparator 3 input a. rg3/ccp4/an17/p3d/ c3inb rg3 ccp4 an17 p3d c3inb 6 i/o i/o i o i st s/t analog analog digital i/o. capture 4 input/compare 4 output/pwm4 output. analog input 18. eccp3 pwm output d. comparator 3 input b. rg4/rtcc/t7cki/t5g/ ccp5/an16/p1d/c3inc rg4 rtcc t7cki ( 3 ) t5g ccp5 an16 p1d c3inc 8 i/o o ii i/o i o i st stst st analog analog digital i/o. rtcc output timer7 clock input. timer5 external clock gate input. capture 5 input/compare 5 output/pwm5 output. analog input 16. eccp1 pwm output d. comparator 3 input c. rg5 7 see the mclr /rg5 pin. table 1-3: pic18f6xk2 2 pinout i/o descriptions (continued) pin name pin number pin type buffer type description qfn/tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 23 pic18f87k22 family v ss 9, 25, 41, 56 p ground reference for logic and i/o pins. v dd 26, 38, 57 p positive supply for logic and i/o pins. av ss 20 p ground reference for analog modules. av dd 19 p positive supply for analog modules. envreg 18 i st enable for on-chip voltage regulator. v ddcore /v cap v ddcore v cap 10 p core logic power or external filter capacitor connection. external filter capacitor connection (regulator enabled/disabled). table 1-3: pic18f6xk2 2 pinout i/o descri ptions (continued) pin name pin number pin type buffer type description qfn/tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
pic18f87k22 family ds39960d-page 24 ? 2009-2011 microchip technology inc. table 1-4: pic18f8xk22 pi nout i/o descriptions pin name pin number pin type buffer type description tqfp mclr /rg5 rg5 mclr 9 ii stst master clear (input) or programming voltage (input). this pin is an active-low reset to the device. general purpose, input only pin. osc1/clki/ra7 osc1 clki ra7 49 ii i/o cmoscmos ttl oscillator crystal or external clock input. oscillator crystal input. external clock source input. always associated with pin function, osc1. (see related osc1/clki, osc2/clko pins.) general purpose i/o pin. osc2/clko/ra6 osc2 clko ra6 50 oo i/o ttl oscillator crystal or clock output. oscillator crystal output. connects to crystal or resonator in crystal oscillator mode. in certain oscillator modes, osc2 pin outputs clko, which has 1/4 the frequency of osc1 and denotes the instruction cycle rate. general purpose i/o pin. legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: psp is available only in microcontroller mode. 5: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 25 pic18f87k22 family porta is a bidirectional i/o port. ra0/an0/ulpwu ra0 an0 ulpwu 30 i/o ii ttl analog analog digital i/o. analog input 0. ultra low-power wake-up input. ra1/an1 ra1 an1 29 i/o i ttl analog digital i/o. analog input 1. ra2/an2/v ref - ra2 an2 v ref - 28 i/o ii ttl analog analog digital i/o. analog input 2. a/d reference voltage (low) input. ra3/an3/v ref + ra3 an3 v ref + 27 i/o ii ttl analog analog digital i/o. analog input 3. a/d reference voltage (high) input. ra4/t0cki ra4 t0cki 34 i/o i stst digital i/o. timer0 external clock input. ra5/an4/t1cki/ t3g/hlvdin ra5 an4 t1cki t3g hlvdin 33 i/o ii i i ttl analog stst analog digital i/o. analog input 4. timer1 clock input. timer3 external clock gate input. high/low-voltage detect input. ra6 see the osc2/clko/ra6 pin. ra7 see the osc1/clki/ra7 pin. table 1-4: pic18f8xk2 2 pinout i/o descri ptions (continued) pin name pin number pin type buffer type description tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: psp is available only in microcontroller mode. 5: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
pic18f87k22 family ds39960d-page 26 ? 2009-2011 microchip technology inc. portb is a bidirectional i/o port. portb can be software programmed for internal weak pull-ups on all inputs. rb0/int0/flt0 rb0 int0 flt0 58 i/o ii ttl stst digital i/o. external interrupt 0. enhanced pwm fault input for eccp1/2/3. rb1/int1 rb1 int1 57 i/o i ttl st digital i/o. external interrupt 1. rb2/int2/cted1 rb2 int2 cted1 56 i/o ii ttl stst digital i/o. external interrupt 2. ctmu edge 1 input. rb3/int3/cted2/ eccp2/p2a rb3 int3 cted2 eccp2 p2a 55 i/o ii i/o o ttl stst st st digital i/o. external interrupt 3. ctmu edge 2 input. capture 2 input/compare 2 output/pwm2 output. enhanced pwm2 output a. rb4/kbi0 rb4 kbi0 54 i/o i ttlttl digital i/o. interrupt-on-change pin. rb5/kbi1/t3cki/t1g rb5 kbi1 t3cki t1g 53 i/o ii i ttlttl stst digital i/o. interrupt-on-change pin. timer3 clock input. timer1 external clock gate input. rb6/kbi2/pgc rb6 kbi2 pgc 52 i/o i i/o ttlttl st digital i/o. interrupt-on-change pin. in-circuit debugger and icsp? programming clock pin. rb7/kbi3/pgd rb7 kbi3 pgd 47 i/o i i/o ttlttl st digital i/o. interrupt-on-change pin. in-circuit debugger and icsp programming data pin. table 1-4: pic18f8xk2 2 pinout i/o descriptions (continued) pin name pin number pin type buffer type description tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: psp is available only in microcontroller mode. 5: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 27 pic18f87k22 family portc is a bidirectional i/o port. rc0/sosco/sckli rc0 sosco sckli 36 i/o o i st st digital i/o. sosc oscillator output. digital sosc input. rc1/sosci/eccp2/p2a rc1 sosci eccp2 (1) p2a 35 i/o i i/o o st cmos st digital i/o. sosc oscillator input. capture 2 input/compare 2 output/pwm2 output. enhanced pwm2 output a. rc2/eccp1/p1a rc2 eccp1 p1a 43 i/oi/o o stst digital i/o. capture 1 input/compare 1 output/pwm1 output. enhanced pwm1 output a. rc3/sck1/scl1 rc3 sck1 scl1 44 i/oi/o i/o stst i 2 c digital i/o. synchronous serial clock input/output for spi mode. synchronous serial clock input/output for i 2 c? mode. rc4/sdi1/sda1 rc4 sdi1 sda1 45 i/o i i/o stst i 2 c digital i/o. spi data in. i 2 c data i/o. rc5/sdo1 rc5 sdo1 46 i/o o st digital i/o. spi data out. rc6/tx1/ck1 rc6 tx1 ck1 37 i/o o i/o st st digital i/o. eusart asynchronous transmit. eusart synchronous clock (see related rx1/dt1). rc7/rx1/dt1 rc7 rx1 dt1 38 i/o i i/o stst st digital i/o. eusart asynchronous receive. eusart synchronous data (see related tx1/ck1). table 1-4: pic18f8xk2 2 pinout i/o descri ptions (continued) pin name pin number pin type buffer type description tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: psp is available only in microcontroller mode. 5: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
pic18f87k22 family ds39960d-page 28 ? 2009-2011 microchip technology inc. portd is a bidirectional i/o port. rd0/psp0/ctpls/ad0 rd0 psp0 (4) ctpls ad0 72 i/oi/o o i/o st ttl st ttl digital i/o parallel slave port data ctmu pulse generator output external memory address/data 0 rd1/t5cki/t7g/psp1/ad1 rd1 t5cki t7g psp1 (4) ad1 69 i/o ii i/oi/o stst st ttlttl digital i/o timer5 clock input timer7 external clock gate input parallel slave port data external memory address/data 1 rd2/psp2/ad2 rd2 psp2 ( 4 ) ad2 68 i/oi/o i/o st ttlttl digital i/o. parallel slave port data. external memory address/data 2. rd3/psp3/ad3 rd3 psp3 ( 4 ) ad3 67 i/oi/o i/o st ttlttl digital i/o. parallel slave port data. external memory address/data 3. rd4/sdo2/psp4/ad4 rd4 sdo2 psp4 ( 4 ) ad4 66 i/o o i/oi/o st ttlttl digital i/o. spi data out. parallel slave port data. external memory address/data 4. rd5/sdi2/sda2/psp5/ ad5 rd5 sdi2 sda2 psp5 ( 4 ) ad5 65 i/o i i/oi/o i/o stst i 2 c ttlttl digital i/o. spi data in. i 2 c? data i/o. parallel slave port data. external memory address/data 5. table 1-4: pic18f8xk2 2 pinout i/o descriptions (continued) pin name pin number pin type buffer type description tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: psp is available only in microcontroller mode. 5: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 29 pic18f87k22 family rd6/sck2/scl2/psp6/ ad6 rd6 sck2 scl2 psp6 ( 4 ) ad6 64 i/oi/o i/o i/o i/o stst i 2 c ttlttl digital i/o. synchronous serial clock input/output for spi mode. synchronous serial clock input/output for i 2 c? mode. parallel slave port data. external memory address/data 6. rd7/ss2 /psp7/ad7 rd7 ss2 psp7 ( 4 ) ad7 63 i/o i i/oi/o st ttlttl ttl digital i/o. spi slave select input. parallel slave port data. external memory address/data 7. table 1-4: pic18f8xk2 2 pinout i/o descri ptions (continued) pin name pin number pin type buffer type description tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: psp is available only in microcontroller mode. 5: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
pic18f87k22 family ds39960d-page 30 ? 2009-2011 microchip technology inc. porte is a bidirectional i/o port. re0/p2d/rd /ad8 re0 p2d rd ( 4 ) ad8 4 i/o o i i/o st ttlttl digital i/o. eccp2 pwm output d. parallel slave port read strobe. external memory address/data 8. re1/p2c/wr /ad9 re1 p2c wr ( 4 ) ad9 3 i/o o i i/o st ttlttl digital i/o. eccp2 pwm output c. parallel slave port write strobe. external memory address/data 9. re2/p2b/ccp10/cs / ad10 re2 p2b ccp10 ( 3 ) cs ( 4 ) ad10 78 i/o o i/o i i/o stst st ttlttl digital i/o. eccp2 pwm output b. capture 10 input/compare 10 output/pwm10 output. parallel slave port chip select. external memory address/data 10. re3/p3c/ccp9/refo ad11 re3 p3c ccp9 ( 3 , 5 ) refo ad11 77 i/o o i/o o i/o st s/t ttl digital i/o. eccp3 pwm output c. capture 9 input/compare 9 output/pwm9 output. reference clock out. external memory address/data 11. re4/p3b/ccp8/ad12 re4 p3b ccp8 ( 5 ) ad12 76 i/o o i/oi/o st st ttl digital i/o. eccp4 pwm output b. capture 8 input/compare 8 output/pwm8 output. external memory address/data 12. re5/p1c/ccp7/ad13 re5 p1c ccp7 ( 5 ) ad13 75 i/o o i/oi/o st st ttl digital i/o. eccp1 pwm output c. capture 7 input/compare 7 output/pwm7 output. external memory address/data 13. table 1-4: pic18f8xk2 2 pinout i/o descriptions (continued) pin name pin number pin type buffer type description tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: psp is available only in microcontroller mode. 5: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 31 pic18f87k22 family re6/p1b/ccp6/ad14 re6 p1b ccp6 ( 5 ) ad14 74 i/o o i/oi/o st stst digital i/o. eccp1 pwm output b. capture 6 input/compare 6 output/pwm6 output. external memory address/data 14. re7/eccp2/p2a/ad15 re7 eccp2 (2) p2aad15 73 i/oi/o o i/o stst st digital i/o. capture 2 input/compare 2 output/pwm2 output. eccp2 pwm output a. external memory address/data 15. table 1-4: pic18f8xk2 2 pinout i/o descri ptions (continued) pin name pin number pin type buffer type description tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: psp is available only in microcontroller mode. 5: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
pic18f87k22 family ds39960d-page 32 ? 2009-2011 microchip technology inc. portf is a bidirectional i/o port. rf1/an6/c2out/ctdin rf1 an6 c2out ctdin 23 i/o i o i st analog st digital i/o. analog input 6. comparator 2 output. ctmu pulse delay input. rf2/an7/c1out rf2 an7 c1out 18 i/o i o st analog digital i/o. analog input 7. comparator 1 output. rf3/an8/c2inb/ctmui rf3 an8 c2inb ctmui 17 i/o ii o st analog analog digital i/o. analog input 8. comparator 2 input b. ctmu pulse generator charger for the c2inb comparator input. rf4/an9/c2ina rf4 an9 c2ina 16 i/o ii st analog analog digital i/o. analog input 9. comparator 2 input a. rf5/an10/c1inb rf5 an10 c1inb 15 i/o ii st analog analog digital i/o. analog input 10. comparator 1 input b. rf6/an11/c1ina rf6 an11 c1ina 14 i/o ii st analog analog digital i/o. analog input 11. comparator 1 input a. rf7/an5/ss1 rf7 an5 ss1 13 i/o o i st analog st digital i/o. analog input 5. spi slave select input. table 1-4: pic18f8xk2 2 pinout i/o descriptions (continued) pin name pin number pin type buffer type description tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: psp is available only in microcontroller mode. 5: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 33 pic18f87k22 family portg is a bidirectional i/o port. rg0/eccp3/p3a rg0 eccp3 p3a 5 i/oi/o o stst digital i/o. capture 3 input/compare 3 output/pwm3 output. eccp3 pwm output a. rg1/tx2/ck2/an19/ c3out rg1 tx2 ck2 an19 c3out 6 i/o o i/o i o st st analog digital i/o. eusart asynchronous transmit. eusart synchronous clock (see related rx2/dt2). analog input 19. comparator 3 output. rg2/rx2/dt2/an18/ c3ina rg2 rx2 dt2 an18 c3ina 7 i/o i i/o ii stst st analog analog digital i/o. eusart asynchronous receive. eusart synchronous data (see related tx2/ck2). analog input 18. comparator 3 input a. rg3/ccp4/an17/p3d/ c3inb rg3 ccp4 an17 p3d c3inb 8 i/oi/o i o i stst analog analog digital i/o. capture 4 input/compare 4 output/pwm4 output. analog input 17. eccp3 pwm output d. comparator 3 input b. rg4/rtcc/t7cki/t5g/ ccp5/an16/p1d/c3inc rg4 rtcc t7cki ( 3 ) t5g ccp5 an16 p1d c3inc 10 i/o o ii i/o i o i st stst st analog analog digital i/o. rtcc output. timer7 clock input. timer5 external clock gate input. capture 5 input/compare 5 output/pwm5 output. analog input 16. eccp1 pwm output d. comparator 3 input c. rg5 9 see the mclr /rg5 pin. table 1-4: pic18f8xk2 2 pinout i/o descri ptions (continued) pin name pin number pin type buffer type description tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: psp is available only in microcontroller mode. 5: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
pic18f87k22 family ds39960d-page 34 ? 2009-2011 microchip technology inc. porth is a bidirectional i/o port. rh0/an23/a16 rh0 an23 a16 79 i/o i i/o st analog ttl digital i/o. analog input 23. external memory address/data 16. rh1/an22/a17 rh1 an22 a17 80 i/o i i/o st analog ttl digital i/o. analog input 22. external address/data 17. rh2/an21/a18 rh2 an21 a18 1 i/o i i/o st analog ttl digital i/o. analog input 21. external address/data 18. rh3/an20/a19 rh3 an20 a19 2 i/o i i/o st analog ttl digital i/o. analog input 20. external address/data 19. rh4/ccp9/p3c/an12/ c2inc rh4 ccp9 ( 3 , 5 ) p3can12 c2inc 22 i/oi/o o ii stst analog analog digital i/o. capture 9 input/compare 9 output/pwm9 output. eccp3 pwm output c. analog input 12. comparator 2 input c. rh5/ccp8/p3b/an13/ c2ind rh5 ccp8 ( 5 ) p3ban13 c2ind 21 i/oi/o o ii stst analog analog digital i/o. capture 8 input/compare 8 output/pwm8 output. eccp3 pwm output b. analog input 13. comparator 1 input d. rh6/ccp7/p1c/an14/ c1inc rh6 ccp7 ( 5 ) p1can14 c1inc 20 i/oi/o o ii stst analog analog digital i/o. capture 7 input/compare 7 output/pwm7 output. eccp1 pwm output c. analog input 14. comparator 1 input c. table 1-4: pic18f8xk2 2 pinout i/o descriptions (continued) pin name pin number pin type buffer type description tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: psp is available only in microcontroller mode. 5: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 35 pic18f87k22 family rh7/ccp6/p1b/an15 rh7 ccp6 ( 5 ) p1ban15 19 i/oi/o o i stst analog digital i/o. capture 6 input/compare 6 output/pwm6 output. eccp1 pwm output b. analog input 15. table 1-4: pic18f8xk2 2 pinout i/o descri ptions (continued) pin name pin number pin type buffer type description tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: psp is available only in microcontroller mode. 5: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
pic18f87k22 family ds39960d-page 36 ? 2009-2011 microchip technology inc. portj is a bidirectional i/o port. rj0/ale rj0 ale 62 i/o o st digital i/o. external memory address latch enable. rj1/oe rj1 oe 61 i/o o st digital i/o. external memory output enable. rj2/wrl rj2 wrl 60 i/o o st digital i/o. external memory write low control. rj3/w r h rj3 w r h 59 i/o o st digital i/o. external memory high control. rj4/ba0 rj4 ba0 39 i/o o st digital i/o. external memory byte address 0 control rj5/ce rj5 ce 40 i/o o st digital i/o external memory chip enable control. rj6/lb rj6 lb 41 i/o o st digital i/o. external memory low byte control. rj7/ub rj7 ub 42 i/o o st digital i/o. external memory high byte control. v ss 11, 31, 51, 70 p ground reference for logic and i/o pins. v dd 32, 48, 71 p positive supply for logic and i/o pins. av ss 26 p ground reference for analog modules. av dd 25 p positive supply for analog modules. envreg 24 i st enable for on-chip voltage regulator. v ddcore /v cap v ddcore v cap 12 p core logic power or external filter capacitor connection. external filter capacitor connection (regulator enabled/disabled). table 1-4: pic18f8xk2 2 pinout i/o descriptions (continued) pin name pin number pin type buffer type description tqfp legend: ttl = ttl compatible input cmos = cmos compatible input or output st = schmitt trigger input with cmos levels analog = analog input i = input o = output p = power od = open-drain (no p diode to v dd ) i 2 c= i 2 c?/smbus note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. 2: alternate assignment for eccp2 when the ccp2mx configuration bit is cleared. 3: not available on pic18f65k22 and pic18f85k22 devices. 4: psp is available only in microcontroller mode. 5: the cc6, ccp7, ccp8 and ccp9 pin placement depends on the setting of the eccpmx configuration bit (config3h<1>). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 37 pic18f87k22 family 2.0 guidelines for getting started with pic18fxxkxx microcontrollers 2.1 basic connection requirements getting started with the pic18f87k22 family family of 8-bit microcontrollers requires attention to a minimal set of device pin connections before proceeding with development. the following pins must always be connected: all v dd and v ss pins (see section 2.2 power supply pins ) all av dd and av ss pins, regardless of whether or not the analog device features are used (see section 2.2 power supply pins ) mclr pin (see section 2.3 master clear (mclr) pin ) envreg (if implemented) and v cap /v ddcore pins (see section 2.4 voltage regulator pins (envreg and v cap /v ddcore ) ) these pins must also be connected if they are being used in the end application: pgc/pgd pins used for in-circuit serial programming? (icsp?) and debugging purposes (see section 2.5 icsp pins ) osci and osco pins when an external oscillator source is used (see section 2.6 external oscillator pins ) additionally, the following pins may be required: v ref +/v ref - pins are used when external voltage reference for analog modules is implemented the minimum mandatory connections are shown in figure 2-1 . figure 2-1: recommended minimum connections note: the av dd and av ss pins must always be connected, regardless of whether any of the analog modules are being used. pic18fxxkxx v dd v ss v dd v ss v ss v dd av dd av ss v dd v ss c1 r1 v dd mclr v cap /v ddcore r2 envreg (1) c7 (2) c2 (2) c3 (2) c4 (2) c5 (2) c6 (2) key (all values are recommendations): c1 through c6: 0.1 ? f, 20v ceramic r1: 10 k ? r2: 100 ? to 470 ? note 1: see section 2.4 voltage regulator pins (envreg and v cap /v ddcore ) for explanation of envreg pin connections. 2: the example shown is for a pic18f device with five v dd /v ss and av dd /av ss pairs. other devices may have more or less pairs; adjust the number of decoupling capacitors appropriately. (1) downloaded from: http:///
pic18f87k22 family ds39960d-page 38 ? 2009-2011 microchip technology inc. 2.2 power supply pins 2.2.1 decoupling capacitors the use of decoupling capacitors on every pair of power supply pins, such as v dd , v ss , av dd and av ss , is required. consider the following criteria when using decoupling capacitors: value and type of capacitor: a 0.1 ? f (100 nf), 10-20v capacitor is recommended. the capacitor should be a low-esr device, with a resonance frequency in the range of 200 mhz and higher. ceramic capacitors are recommended. placement on the printed circuit board: the decoupling capacitors should be placed as close to the pins as possible. it is recommended to place the capacitors on the same side of the board as the device. if space is constricted, the capacitor can be placed on another layer on the pcb using a via; however, ensure that the trace length from the pin to the capacitor is no greater than 0.25 inch (6 mm). handling high-frequency noise: if the board is experiencing high-frequency noise (upward of tens of mhz), add a second ceramic type capaci- tor in parallel to the above described decoupling capacitor. the value of the second capacitor can be in the range of 0.01 ? f to 0.001 ? f. place this second capacitor next to each primary decoupling capacitor. in high-speed circuit designs, consider implementing a decade pair of capacitances as close to the power and ground pins as possible (e.g., 0.1 ? f in parallel with 0.001 ? f). maximizing performance: on the board layout from the power supply circuit, run the power and return traces to the decoupling capacitors first, and then to the device pins. this ensures that the decoupling capacitors are first in the power chain. equally important is to keep the trace length between the capacitor and the power pins to a minimum, thereby reducing pcb trace inductance. 2.2.2 tank capacitors on boards with power traces running longer than six inches in length, it is suggested to use a tank capac- itor for integrated circuits, including microcontrollers, to supply a local power source. the value of the tank capacitor should be determined based on the trace resistance that connects the power supply source to the device, and the maximum current drawn by the device in the application. in other words, select the tank capacitor so that it meets the acceptable voltage sag at the device. typical values range from 4.7 ? f to 47 ? f. 2.3 master clear (mclr ) pin the mclr pin provides two specific device functions: device reset, and device programming and debugging. if programming and debugging are not required in the end application, a direct connection to v dd may be all that is required. the addition of other components, to help increase the applications resistance to spurious resets from voltage sags, may be beneficial. a typical configuration is shown in figure 2-1 . other circuit designs may be implemented, depending on the applications requirements. during programming and debugging, the resistance and capacitance that can be added to the pin must be considered. device programmers and debuggers drive the mclr pin. consequently, specific voltage levels (v ih and v il ) and fast signal transitions must not be adversely affected. therefore, specific values of r1 and c1 will need to be adjusted based on the application and pcb requirements. for example, it is recommended that the capacitor, c1, be isolated from the mclr pin during programming and debugging operations by using a jumper ( figure 2-2 ). the jumper is replaced for normal run-time operations. any components associated with the mclr pin should be placed within 0.25 inch (6 mm) of the pin. figure 2-2: example of mclr pin connections note 1: r1 ?? 10 k ? is recommended. a suggested starting value is 10 k ? . ensure that the mclr pin v ih and v il specifications are met. 2: r2 ?? 470 ? will limit any current flowing into mclr from the external capacitor, c, in the event of mclr pin breakdown, due to electrostatic discharge (esd) or electrical overstress (eos). ensure that the mclr pin v ih and v il specifications are met. c1 r2 r1 v dd mclr pic18fxxkxx jp downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 39 pic18f87k22 family 2.4 voltage regulator pins (envreg and v cap /v ddcore ) the on-chip voltage regulator enable pin, envreg, must always be connected directly to either a supply voltage or to ground. tying envreg to v dd enables the regulator, while tying it to ground disables the regulator. refer to section 28.3 on-chip voltage regulator for details on connecting and using the on-chip regulator. when the regulator is enabled, a low-esr (< 5 ? ) capacitor is required on the v cap /v ddcore pin to stabilize the voltage regulator output voltage. the v cap /v ddcore pin must not be connected to v dd and must use a capacitor of 10 f connected to ground. the type can be ceramic or tantalum. suitable examples of capacitors are shown in ta bl e 2 - 1 . capacitors with equivalent specifications can be used. designers may use figure 2-3 to evaluate esr equivalence of candidate devices. it is recommended that the trace length not exceed 0.25 inch (6 mm). refer to section 31.0 electrical characteristics for additional information. when the regulator is disabled, the v cap /v ddcore pin must be tied to a voltage supply at the v ddcore level. refer to section 31.0 electrical characteristics for information on v dd and v ddcore . some pic18fxxkxx families, or some devices within a family, do not provide the option of enabling or disabling the on-chip voltage regulator: some devices (with the name, pic18 lf xxkxx) permanently disable the voltage regulator. these devices do not have the envreg pin and require a 0.1 ? f capacitor on the v cap /v ddcore pin. the v dd level of these devices must comply with the voltage regulator disabled specification for parameter d001, in section 31.0 electrical characteristics . some devices permanently enable the voltage regulator. these devices also do not have the envreg pin. the 10 ? f capacitor is still required on the v cap /v ddcore pin. figure 2-3: frequency vs. esr performance for suggested v cap . 10 1 0.1 0.01 0.001 0.01 0.1 1 10 100 1000 10,000 frequency (mhz) esr ( ? ) note: typical data measurement at 25c, 0v dc bias. table 2-1: suitable capacitor equivalents make part # nominal capacitance base tolerance rated voltage temp. range tdk c3216x7r1c106k 10 f 10% 16v -55 to 125oc tdk c3216x5r1c106k 10 f 10% 16v -55 to 85oc panasonic ecj-3yx1c106k 10 f 10% 16v -55 to 125oc panasonic ecj-4yb1c106k 10 f 10% 16v -55 to 85oc murata grm32dr71c106ka01l 10 f 10% 16v -55 to 125oc murata grm31cr61c106kc31l 10 f 10% 16v -55 to 85oc downloaded from: http:///
pic18f87k22 family ds39960d-page 40 ? 2009-2011 microchip technology inc. 2.4.1 considerations for ceramic capacitors in recent years, large value, low-voltage, surface-mount ceramic capacitors have become very cost effective in sizes up to a few tens of microfarad. the low-esr, small physical size and other properties make ceramic capacitors very attractive in many types of applications. ceramic capacitors are suitable for use with the inter- nal voltage regulator of this microcontroller. however, some care is needed in selecting the capacitor to ensure that it maintains sufficient capacitance over the intended operating range of the application. typical low-cost, 10 ? f ceramic capacitors are available in x5r, x7r and y5v dielectric ratings (other types are also available, but are less common). the initial toler- ance specifications for these types of capacitors are often specified as 10% to 20% (x5r and x7r), or -20%/+80% (y5v). however, the effective capacitance that these capacitors provide in an application circuit will also vary based on additional factors, such as the applied dc bias voltage and the temperature. the total in-circuit tolerance is, therefore, much wider than the initial tolerance specification. the x5r and x7r capacitors typically exhibit satisfac- tory temperature stability (ex: 15% over a wide temperature range, but consult the manufacturers data sheets for exact specifications). however, y5v capaci- tors typically have extreme temperature tolerance specifications of +22%/-82%. due to the extreme temperature tolerance, a 10 ? f nominal rated y5v type capacitor may not deliver enough total capacitance to meet minimum internal voltage regulator stability and transient response requirements. therefore, y5v capacitors are not recommended for use with the internal regulator if the application must operate over a wide temperature range. in addition to temperature tolerance, the effective capacitance of large value ceramic capacitors can vary substantially, based on the amount of dc voltage applied to the capacitor. this effect can be very signifi- cant, but is often overlooked or is not always documented. a typical dc bias voltage vs. capacitance graph for x7r type and y5v type capacitors is shown in figure 2-4 . figure 2-4: dc bias voltage vs. capacitance characteristics when selecting a ceramic capacitor to be used with the internal voltage regulator, it is suggested to select a high-voltage rating, so that the operating voltage is a small percentage of the maximum rated capacitor volt- age. for example, choose a ceramic capacitor rated at 16v for the 2.5v core voltage. suggested capacitors are shown in table 2-1 . 2.5 icsp pins the pgc and pgd pins are used for in-circuit serial programming? (icsp?) and debugging purposes. it is recommended to keep the trace length between the icsp connector and the icsp pins on the device as short as possible. if the icsp connector is expected to experience an esd event, a series resistor is recom- mended, with the value in the range of a few tens of ohms, not to exceed 100 ? . pull-up resistors, series diodes and capacitors on the pgc and pgd pins are not recommended as they will interfere with the programmer/debugger communica- tions to the device. if such discrete components are an application requirement, they should be removed from the circuit during programming and debugging. alter- natively, refer to the ac/dc characteristics and timing requirements information in the respective device flash programming specification for information on capacitive loading limits, and pin input voltage high (v ih ) and input low (v il ) requirements. for device emulation, ensure that the communication channel select (i.e., pgcx/pgdx pins), programmed into the device, matches the physical connections for the icsp to the microchip debugger/emulator tool. for more information on available microchip development tools connection requirements, refer to section 30.0 development support . -80 -70 -60 -50 -40 -30 -20 -10 0 10 5 1011121314151617 dc bias voltage (vdc) capacitance change (%) 01234 6789 16v capacitor 10v capacitor 6.3v capacitor downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 41 pic18f87k22 family 2.6 external oscillator pins many microcontrollers have options for at least two oscillators: a high-frequency primary oscillator and a low-frequency secondary oscillator (refer to section 3.0 oscillator configurations for details). the oscillator circuit should be placed on the same side of the board as the device. place the oscillator circuit close to the respective oscillator pins with no more than 0.5 inch (12 mm) between the circuit components and the pins. the load capacitors should be placed next to the oscillator itself, on the same side of the board. use a grounded copper pour around the oscillator cir- cuit to isolate it from surrounding circuits. the grounded copper pour should be routed directly to the mcu ground. do not run any signal traces or power traces inside the ground pour. also, if using a two-sided board, avoid any traces on the other side of the board where the crystal is placed. layout suggestions are shown in figure 2-4. in-line packages may be handled with a single-sided layout that completely encompasses the oscillator pins. with fine-pitch packages, it is not always possible to com- pletely surround the pins and components. a suitable solution is to tie the broken guard sections to a mirrored ground layer. in all cases, the guard trace(s) must be returned to ground. in planning the applications routing and i/o assign- ments, ensure that adjacent port pins, and other signals in close proximity to the oscillator, are benign (i.e., free of high frequencies, short rise and fall times, and other similar noise). for additional information and design guidance on oscillator circuits, please refer to these microchip application notes, available at the corporate web site (www.microchip.com): an826, crystal oscillator basics and crystal selection for rfpic? and picmicro ? devices an849, basic picmicro ? oscillator design an943, practical picmicro ? oscillator analysis and design an949, making your oscillator work 2.7 unused i/os unused i/o pins should be configured as outputs and driven to a logic low state. alternatively, connect a 1 k ? to 10 k ? resistor to v ss on unused pins and drive the output to logic low. figure 2-5: suggested placement of the oscillator circuit gnd `` ` osc1 osc2 t1oso t1os i copper pour primary oscillator crystal timer1 oscillator crystal device pins primary oscillator c1c2 t1 oscillator: c1 t1 oscillator: c2 (tied to ground) single-sided and in-line layouts: fine-pitch (dual-sided) layouts: gnd osco osci bottom layer copper pour oscillator crystal top layer copper pour c2 c1 device pins (tied to ground) (tied to ground) downloaded from: http:///
pic18f87k22 family ds39960d-page 42 ? 2009-2011 microchip technology inc. notes: downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 43 pic18f87k22 family 3.0 oscillator configurations 3.1 oscillator types the pic18f87k22 family of devices can be operated in the following oscillator modes: ec external clock, ra6 available ecio external clock, clock out ra6 (f osc /4 on ra6) hs high-speed crystal/resonator xt crystal/resonator lp low-power crystal rc external resistor/capacitor, ra6 available rcio external resistor/capacitor, clock out ra6 (f osc /4 on ra6) intio2 internal oscillator with i/o on ra6 and ra7 intio1 internal oscillator with f osc /4 output on ra6 and i/o on ra7 there is also an option for running the 4xpll on any of the clock sources in the input frequency range of 4 to 16 mhz. the pll is enabled by setting the pllcfg bit (config1h<4>) or the pllen bit (osctune<6>). for the ec and hs mode, the pllen (software) or pllcfg (config) bit can be used to enable the pll. for the intiox modes (hf-intosc): only the pllen can enable the pll (pllcfg is ignored). when the oscillator is configured for the internal oscillator (fosc<3:0> = 100x ), the pll can be enabled only when the hf-intosc frequency is 8 or 16 mhz. when the ra6 and ra7 pins are not used for an oscil- lator function or clkout function, they are available as general purpose i/os. to optimize power consumption when using ec/hs/ xt/lp/rc as the primary oscillator, the frequency input range can be configured to yield an optimized power bias: low-power bias C external frequency less than 160 khz medium power bias C external frequency between 160 khz and 16 mhz high-power bias C external frequency greater than 16 mhz all of these modes are selected by the user by programming the fosc<3:0> configuration bits (config1h<3:0>). in addition, pic18f87k22 family devices can switch between different clock sources, either under software control or, under certain condi- tions, automatically. this allows for additional power savings by managing device clock speed in real time without resetting the application. the clock sources for the pic18f87k22 family of devices are shown in figure 3-1 . for the hs and ec mode, there are additional power modes of operation C depending on the frequency of operation. hs1 is the medium power mode with a frequency range of 4 mhz to 16 mhz. hs2 is the high-power mode, where the oscillator frequency can go from 16 mhz to 25 mhz. hs1 and hs2 are achieved by set- ting the config1h<3:0> correctly. (for details, see register 28-2 on page 406 .) ec mode has these modes of operation: ec1 C for low power with a frequency range up to 160 khz ec2 C medium power with a frequency range of 160 khz to 16 mhz ec3 C high power with a frequency range of 16 mhz to 64 mhz ec1, ec2 and ec3 are achieved by setting the config1h<3:0> correctly. (for details, see register 28-2 on page 406 .) table 3-1 shows the hs and ec modes frequency range and fosc<3:0> settings. downloaded from: http:///
pic18f87k22 family ds39960d-page 44 ? 2009-2011 microchip technology inc. figure 3-1: pic18f87k22 family clock diagram table 3-1: hs, ec, xt, lp and rc modes: ranges and settings mode frequency range fosc<3:0> setting ec1 (low power) dc-160 khz 1101 (ec1 & ec1io) 1100 ec2 (medium power) 160khz-16mhz 1011 (ec2 & ec2io) 1010 ec3 (high power) 16 mhz-64 mhz 0101 (ec3 & ec3io) 0100 hs1 (medium power) 4 mhz-16 mhz 0011 hs2 (high power) 16 mhz-25 mhz 0010 xt 100 khz-4 mhz 0001 lp 31.25 khz 0000 rc (external) 0-4 mhz 001x intio 32 khz-16 mhz 100x (and osccon, osccon2) osc2 osc1 sosco sosci hf intosc 16 mhz to 31 khz mf intosc 500 khz to 31 khz lf intosc 31 khz postscaler postscaler 16 mhz 8 mhz 4 mhz 2 mhz 1 mhz 500 khz 250 khz 31 khz 500 khz 250 khz 31 khz 31 khz 16 mhz 8 mhz 4 mhz 2 mhz 1 mhz 500 khz 250 khz 31 khz 4x pll fosc<3:0> intsrc mux mux mux mux mfiosel mux peripherals cpu idlen clock control fosc<3:0> scs<1:0> 111 110101 100 011 010 001 000 ircf<2:0> mux pllen and pllcfg downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 45 pic18f87k22 family 3.2 control registers the osccon register ( register 3-1 ) controls the main aspects of the device clocks operation. it selects the oscillator type to be used, which of the power-managed modes to invoke and the output frequency of the intosc source. it also provides status on the oscillators. the osctune register ( register 3-3 ) controls the tuning and operation of the internal oscillator block. it also implements the pllen bit which controls the operation of the phase locked loop (pll) (see section 3.5.3 pll frequency multiplier ). register 3-1: osccon: os cillator control register ( 1 ) r/w-0 r/w-1 r/w-1 r/w-0 r ( 1 ) r-0 r/w-0 r/w-0 idlen ircf2 ( 2 ) ircf1 ( 2 ) ircf0 ( 2 ) osts hfiofs scs1 ( 4 ) scs0 ( 4 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 idlen: idle enable bit 1 = device enters an idle mode when a sleep instruction is executed 0 = device enters sleep mode when a sleep instruction is executed bit 6-4 ircf<2:0>: internal oscillator frequency select bits ( 2 ) 111 = hf-intosc output frequency is used (16 mhz) 110 = hf-intosc/2 output frequency is used (8 mhz, default) 101 = hf-intosc/4 output frequency is used (4 mhz) 100 = hf-intosc/8 output frequency is used (2 mhz) 011 = hf-intosc/16 output frequency is used (1 mhz) if intsrc = 0 and mfiosel = 0 : ( 3 , 5 ) 010 = hf-intosc/32 output frequency is used (500 khz) 001 = hf-intosc/64 output frequency is used (250 khz) 000 = lf-intosc output frequency is used (31.25 khz) if intsrc = 1 and mfiosel = 0 : ( 3 , 5 ) 010 = hf-intosc/32 output frequency is used (500 khz) 001 = hf-intosc/64 output frequency is used (250 khz) 000 = hf-intosc/512 output frequency is used (31.25 khz) if intsrc = 0 and mfiosel = 1 : ( 3 , 5 ) 010 = mf-intosc output frequency is used (500 khz) 001 = mf-intosc/2 output frequency is used (250 khz) 000 = lf-intosc output frequency is used (31.25 khz) (6) if intsrc = 1 and mfiosel = 1 : ( 3 , 5 ) 010 = mf-intosc output frequency is used (500 khz) 001 = mf-intosc/2 output frequency is used (250 khz) 000 = mf-intosc/16 output frequency is used (31.25 khz) bit 3 osts: oscillator start-up timer time-out status bit ( 1 ) 1 = oscillator start-up timer (ost) time-out has expired; primary oscillator is running, as defined by fosc<3:0> 0 = oscillator start-up timer (ost) time-out is running; primary oscillator is not ready C device is running from internal oscillator (hf-intosc, mf-intosc or lf-intosc) note 1: the reset state depends on the state of the ieso configuration bit (config1h<7>). 2: modifying these bits will cause an immediate clock frequency switch if the internal oscillator is providing the device clocks. 3: source selected by the intsrc bit (osctune<7>). 4: modifying these bits will cause an immediate clock source switch. 5: intsrc = osctune<7> and mfiosel = osccon2<0>. 6: lowest power option for an internal source. downloaded from: http:///
pic18f87k22 family ds39960d-page 46 ? 2009-2011 microchip technology inc. bit 2 hfiofs: intosc frequency stable bit 1 = hf-intosc oscillator frequency is stable 0 = hf-intosc oscillator frequency is not stable bit 1-0 scs<1:0>: system clock select bits ( 4 ) 1x = internal oscillator block (lf-intosc, mf-intosc or hf-intosc) 01 = sosc oscillator 00 = default primary oscillator (osc1/osc2 or hf-intosc with or without pll; defined by the fosc<3:0> configuration bits, config1h<3:0>.) register 3-1: osccon: os cillator control register ( 1 ) (continued) note 1: the reset state depends on the state of the ieso configuration bit (config1h<7>). 2: modifying these bits will cause an immediate clock frequency switch if the internal oscillator is providing the device clocks. 3: source selected by the intsrc bit (osctune<7>). 4: modifying these bits will cause an immediate clock source switch. 5: intsrc = osctune<7> and mfiosel = osccon2<0>. 6: lowest power option for an internal source. register 3-2: osccon2: osci llator control register 2 u-0 r-0 u-0 u-0 r/w-0 u-0 r-x r/w-0 soscrun s o s c g o mfiofs mfiosel bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 unimplemented: read as 0 bit 6 soscrun: sosc run status bit 1 = system clock comes from a secondary sosc 0 = system clock comes from an oscillator other than sosc bit 5-4 unimplemented: read as 0 bit 3 soscgo: oscillator start control bit 1 = oscillator is running, even if no other sources are requesting it 0 = oscillator is shut off if no other sources are requesting it (when the sosc is selected to run from a digital clock input, rather than an external crystal, this bit has no effect.) bit 2 unimplemented: read as 0 bit 1 mfiofs: mf-intosc frequency stable bit 1 = mf-intosc is stable 0 = mf-intosc is not stable bit 0 mfiosel: mf-intosc select bit 1 = mf-intosc is used in place of hf-intosc frequencies of 500 khz, 250 khz and 31.25 khz 0 = mf-intosc is not used downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 47 pic18f87k22 family register 3-3: osctune: osci llator tuning register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 intsrc pllen tun5 tun4 tun3 tun2 tun1 tun0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 intsrc: internal oscillator low-frequency source select bit 1 = 31.25 khz device clock derived from 16 mhz intosc source (divide-by-512 enabled, hf-in tosc) 0 = 31 khz device clock derived from intrc 31 khz oscillator (lf-intosc) bit 6 pllen: frequency multiplier pll enable bit 1 = pll is enabled 0 = pll is disabled bit 5-0 tun<5:0>: fast rc oscillator (intosc) frequency tuning bits 011111 = maximum frequency 000001 000000 = center frequency; fast rc oscillator is running at the calibrated frequency 111111 100000 = minimum frequency downloaded from: http:///
pic18f87k22 family ds39960d-page 48 ? 2009-2011 microchip technology inc. 3.3 clock sources and oscillator switching essentially, pic18f87k22 family devices have these independent clock sources: primary oscillators secondary oscillators internal oscillator the primary oscillators can be thought of as the main device oscillators. these are any external oscillators connected to the osc1 and osc2 pins, and include the external crystal and resonator modes and the external clock modes. if selected by the fosc<3:0> configuration bits (config1h<3:0>), the internal oscillator block may be considered a primary oscillator. the internal oscillator block can be one of the following: 31 khz lf-intrc source 31 khz to 500 khz mf-intosc source 31 khz to 16 mhz hf-intosc source the particular mode is defined by the fosc configuration bits. the details of these modes are covered in section 3.5 external oscillator modes . the secondary oscillators are external clock sources that are not connected to the osc1 or osc2 pin. these sources may continue to operate, even after the controller is placed in a power-managed mode. pic18f87k22 family devices offer the sosc (timer1/3/5/7) oscillator as a secondary oscillator source. this oscillator, in all power-managed modes, is often the time base for functions, such as a real-time clock (rtc). the sosc can be enabled from any peripheral that requests it. there are eight ways the sosc can be enabled: if the sosc is selected as the source by any of the odd timers, which is done by each respective soscen bit (txcon<3>), if the sosc is selected as the rtcc source by the rtcosc configuration bit (config3l<1>), if the sosc is selected as the cpu clock source by the scs bits (osccon<1:0>) or if the soscgo bit is set (oscco n2<3>). the soscgo bit is used to warm up the sosc so that it is ready before any peripheral requests it. the secondary oscillator has three run modes. the soscsel<1:0> bits (config1l<4:3>) decide the sosc mode of operation: 11 = high-power sosc circuit 10 = digital (sclki) mode 01 = low-power sosc circuit if a secondary oscillator is not desired and digital i/o on port pins, rc0 and rc1, is needed, the soscsel bits must be set to digital mode. in addition to being a primary clock source in some circumstances, the internal oscillator is available as a power-managed mode clock source. the lf-intosc source is also used as the clock source for several special features, such as the wdt and fail-safe clock monitor. the internal oscillator block is discussed in more detail in section 3.6 internal oscillator block . the pic18f87k22 family includes features that allow the device clock source to be switched from the main oscillator, chosen by device configuration, to one of the alternate clock sources. when an alternate clock source is enabled, various power-managed operating modes are available. 3.3.1 osc1/osc2 oscillator the osc1/osc2 oscillator block is used to provide the oscillator modes and frequency ranges: the crystal-based oscillators (xt, hs and lp) have a built-in start-up time. the operation of the ec and extrc clocks is immediate. 3.3.2 clock source selection the system clock select bits, scs<1:0> (osccon2<1:0>), select the clock source. the avail- able clock sources are the primary clock defined by the fosc<3:0> configuration bits, the secondary clock (sosc oscillator) and the internal oscillator. the clock source changes after one or more of the bits is written to, following a brief clock transition interval. the osts (osccon<3>) and soscrun (osccon<6>) bits indicate which clock source is currently providing the device clock. the osts bit indicates that the oscillator start-up timer (ost) has timed out and the primary clock is providing the device clock in primary clock modes. the soscrun bit indi- cates when the sosc oscillator (from timer1/3/5/7) is providing the device clock in secondary clock modes. in power-managed modes, only one of these bits will be set at any time. if neither of these bits is set, the intrc is providing the clock, or the internal oscillator has just started and is not yet stable. the idlen bit (osccon<7>) determines if the device goes into sleep mode or one of the idle modes when the sleep instruction is executed. mode design operating frequency lp 31.25-100 khz xt 100 khz to 4 mhz hs 4 mhz to 25 mhz ec 0 to 64 mhz (external clock) extrc 0 to 4 mhz (external rc) downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 49 pic18f87k22 family the use of the flag and control bits in the osccon register is discussed in more detail in section 4.0 power-managed modes . 3.3.2.1 system clock selection and device resets since the scs bits are cleared on all forms of reset, this means the primary oscillator, defined by the fosc<3:0> configuration bits, is used as the primary clock source on device resets. this could either be the internal oscillator block by itself, or one of the other primary clock source (hs, ec, xt, lp, external rc and pll-enabled modes). in those cases when the internal oscillator block, with- out pll, is the default clock on reset, the fast rc oscillator (intosc) will be used as the device clock source. it will initially start at 8 mhz; the postscaler selection that corresponds to the reset value of the ircf<2:0> bits ( 110 ). regardless of which primary oscillator is selected, intrc will always be enabled on device power-up. it serves as the clock source until the device has loaded its configuration values from memory. it is at this point that the fosc configuration bits are read and the oscillator selection of the operational mode is made. note that either the primary clock source or the internal oscillator will have two bit setting options for the possible values of the scs<1:0> bits, at any given time. 3.3.3 oscillator transitions pic18f87k22 family devices contain circuitry to prevent clock glitches when switching between clock sources. a short pause in the device clock occurs during the clock switch. the length of this pause is the sum of two cycles of the old clock source and three to four cycles of the new clock source. this formula assumes that the new clock source is stable. clock transitions are discussed in greater detail in section 4.1.2 entering power-managed modes . 3.4 rc oscillator for timing-insensitive applications, the rc and rcio oscillator modes offer additional cost savings. the actual oscillator frequency is a function of several factors: supply voltage values of the external resistor (r ext ) and capacitor (c ext ) operating temperature given the same device, operating voltage and temper- ature, and component values, there will also be unit to unit frequency variations. these are due to factors, such as: normal manufacturing variation difference in lead frame capacitance between package types (especially for low c ext values) variations within the tolerance of limits of r ext and c ext in the rc oscillator mode, the oscillator frequency, divided by 4, is available on the osc2 pin. this signal may be used for test purposes or to synchronize other logic. figure 3-2 shows how the r/c combination is connected. figure 3-2: rc oscillator mode the rcio oscillator mode ( figure 3-3 ) functions like the rc mode, except that the osc2 pin becomes an additional general purpose i/o pin. the i/o pin becomes bit 6 of porta (ra6). figure 3-3: rcio oscillator mode note 1: the timer1/3/5/7 oscillator must be enabled to select the secondary clock source. the timerx oscillator is enabled by setting the soscen bit in the timerx con- trol register (txcon<3>). if the timerx oscillator is not enabled, then any attempt to select a secondary clock source when executing a sleep instruction will be ignored. 2: it is recommended that the timerx oscillator be operating and stable before executing the sleep instruction or a very long delay may occur while the timerx oscillator starts. osc2/clko c ext r ext pic18f87k22 osc1 f osc /4 internal clock v dd v ss recommended values: 3 k ? ? r ext ? 100 k ? 20 pf ?? c ext ? 300 pf c ext r ext pic18f87k22 osc1 internal clock v dd v ss recommended values: 3 k ? ? r ext ? 100 k ? 20 pf ?? c ext ? 300 pf i/o (osc2) ra6 downloaded from: http:///
pic18f87k22 family ds39960d-page 50 ? 2009-2011 microchip technology inc. 3.5 external oscillator modes 3.5.1 crystal oscillator/ceramic resonators (hs modes) in hs or hspll oscillator modes, a crystal or ceramic resonator is connected to the osc1 and osc2 pins to establish oscillation. figure 3-4 shows the pin connections. the oscillator design requires the use of a crystal rated for parallel resonant operation. table 3-2: capacitor selection for ceramic resonators table 3-3: capacitor selection for crystal oscillator figure 3-4: crystal/ceramic resonator operation (hs or hspll configuration) note: use of a crystal rated for series resonant operation may give a frequency out of the crystal manufacturers specifications. typical capacitor values used: mode freq. osc1 osc2 hs 8.0 mhz 16.0 mhz 27 pf 22 pf 27 pf22 pf capacitor values are for design guidance only. different capacitor values may be required to produce acceptable oscillator operation. the user should test the performance of the oscillator over the expected v dd and temperature range for the application. refer to the following application notes for oscillator-specific information: an588, pic ? microcontroller oscillator design guide an826, crystal oscillator basics and crystal selection for rfpic ? and pic ? devices an849, basic pic ? oscillator design an943, practical pic ? oscillator analysis and design an949, making your oscillator work see the notes following tab l e 3 - 3 for additional information. osc type crystal freq. typical capacitor values tested: c1 c2 hs 4 mhz 27 pf 27 pf 8 mhz 22 pf 22 pf 20 mhz 15 pf 15 pf capacitor values are for design guidance only. different capacitor values may be required to produce acceptable oscillator operation. the user should test the performance of the oscillator over the expected v dd and temperature range for the application. refer to the microchip application notes cited in table 3-2 for oscillator-specific information. also see the notes following this table for additional information. note 1: higher capacitance increases the stability of the oscillator but also increases the start-up time. 2: since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components. 3: rs may be required to avoid overdriving crystals with a low drive level specification. 4: always verify oscillator performance over the v dd and temperature range that is expected for the application. note 1: see ta b l e 3 - 2 and table 3-3 for initial values of c1 and c2. 2: a series resistor (r s ) may be required for at strip cut crystals. 3: r f varies with the oscillator mode chosen. c1 (1) c2 (1) xtal osc2 osc1 r f (3) sleep tologic r s (2) internal pic18f87k22 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 51 pic18f87k22 family 3.5.2 external clock input (ec modes) the ec and ecpll oscillator modes require an external clock source to be connected to the osc1 pin. there is no oscillator start-up time required after a power-on reset or after an exit from sleep mode. in the ec oscillator mode, the oscillator frequency, divided by 4, is available on the osc2 pin. this signal may be used for test purposes or to synchronize other logic. figure 3-5 shows the pin connections for the ec oscillator mode. figure 3-5: ex ternal clock input operation (ec configuration) an external clock source may also be connected to the osc1 pin in hs mode, as shown in figure 3-6 . in this configuration, the divide-by-4 output on osc2 is not available. current consumption in this configuration will be somewhat higher than ec mode, as the internal oscillators feedback circuitry will be enabled (in ec mode, the feedback circuit is disabled). figure 3-6: exter nal clock input operation (hs osc configuration) 3.5.3 pll frequency multiplier a phase locked loop (pll) circuit is provided as an option for users who want to use a lower frequency oscillator circuit, or to clock the device up to its highest rated frequency from a crystal oscillator. this may be useful for customers who are concerned with emi due to high-frequency crystals, or users who require higher clock speeds from an internal oscillator. 3.5.3.1 hspll and ecpll modes the hspll and ecpll modes provide the ability to selectively run the device at four times the external oscillating source to produce frequencies up to 64 mhz. the pll is enabled by setting the pllen bit (osctune<6>) or the pllcfg bit (config1h<4>). the pllen bit provides a software control for the pll, even if pllcfg is set to 0 . the pll is enabled only when the hs or ec oscillator frequency is within the 4 mhz to16 mhz input range. this enables additional flexibility for controlling the applications clock speed in software. the pllen should be enabled in hs or ec oscillator mode only if the input frequency is in the range of 4 mhz-16 mhz. figure 3-7: pll block diagram 3.5.3.2 pll and hf-intosc the pll is available to the internal oscillator block when the internal oscillator block is configured as the primary clock source. in this configuration, the pll is enabled in software and generates a clock output of up to 64 mhz. the operation of intosc with the pll is described in section 3.6.2 intpll modes . care should be taken that the pll is enabled only if the hf-intosc postscaler is configured for 8 mhz or 16 mhz . osc1/clki osc2/clko f osc /4 clock from ext. system pic18f87k22 osc1 osc2 open clock from ext. system (hs mode) pic18f87k22 mux vco loop filter osc2 osc1 pll enable (osctune) f in f out sysclk phase comparator pllcfg (config1h<4>) ? 4 hs or ec mode downloaded from: http:///
pic18f87k22 family ds39960d-page 52 ? 2009-2011 microchip technology inc. 3.6 internal oscillator block the pic18f87k22 family of devices includes an internal oscillator block which generates two different clock signals. either clock can be used as the microcontrollers clock source, which may eliminate the need for an external oscillator circuit on the osc1 and/or osc2 pins. the internal oscillator consists of three blocks, depending on the frequency of operation. they are hf-intosc, mf-intosc and lf-intrc. in hf-intosc mode, the internal oscillator can provide a frequency ranging from 31 khz to 16 mhz, with the postscaler deciding the selected frequency (ircf<2:0>). the intsrc bit (osctune<7>) and mfiosel bit (osccon2<0>) also decide which intosc provides the lower frequency (500 khz to 31 khz). for the hf-intosc to provide these frequencies, intsrc = 1 and mfiosel = 0 . in hf-intosc, the postscaler (ircf<2:0>) provides the frequency range of 31 khz to 16 mhz. if hf-intosc is used with the pll, the input frequency to the pll should be 8 mhz or 16 mhz (ircf<2:0> = 111 or 110 ). for mf-intosc mode to provide a frequency range of 500 khz to 31 khz, intsrc = 1 and mfiosel = 1 . the postscaler (ircf<2:0>), in this mode, provides the frequency range of 31 khz to 500 khz. the lf-intrc can provide only 31 khz if intsrc = 0 . the lf-intrc provides 31 khz and is enabled if it is selected as the device clock source. the mode is enabled automatically when any of the following are enabled: power-up timer fail-safe clock monitor watchdog timer two-speed start-up these features are discussed in greater detail in section 28.0 special features of the cpu . the clock source frequency (hf-intosc, mf-intosc or lf-intrc direct) is selected by configuring the ircf bits of the osccon register, as well the intsrc and mfiosel bits. the default frequency on device resets is 8 mhz. 3.6.1 intio modes using the internal oscillator as the clock source elimi- nates the need for up to two external oscillator pins, which can then be used for digital i/o. two distinct oscillator configurations, which are determined by the fosc configuration bits, are available: in intio1 mode, the osc2 pin (ra6) outputs f osc /4, while osc1 functions as ra7 (see figure 3-8 ) for digital input and output. in intio2 mode, osc1 functions as ra7 and osc2 functions as ra6 (see figure 3-9 ). both are available as digital input and output ports. figure 3-8: intio1 oscillator mode figure 3-9: intio2 oscillator mode 3.6.2 intpll modes the 4x phase lock loop (pll) can be used with the hf-intosc to produce faster device clock speeds than are normally possible with the internal oscillator sources. when enabled, the pll produces a clock speed of 32 mhz or 64 mhz. pll operation is controlled through software. the control bit, pllen (osctune<6>), is used to enable or disable its operation. additionally, the pll will only func- tion when the selected hf-intosc frequency is either 8 mhz or 16 mhz (osccon<6:4> = 111 or 110 ). like the intio modes, there are two distinct intpll modes available: in intpll1 mode, the osc2 pin outputs f osc /4, while osc1 functions as ra7 for digital input and output. externally, this is identical in appearance to intio1 ( figure 3-8 ). in intpll2 mode, osc1 functions as ra7 and osc2 functions as ra6, both for digital input and output. externally, this is identical to intio2 ( figure 3-9 ). osc2 f osc /4 i/o (osc1) ra7 pic18f87k22 i/o (osc2) ra6 i/o (osc1) ra7 pic18f87k22 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 53 pic18f87k22 family 3.6.3 internal oscillator output frequency and tuning the internal oscillator block is calibrated at the factory to produce an intosc output frequency of 16 mhz. it can be adjusted in the users application by writing to tun<5:0> (osctune<5:0>) in the osctune register ( register 3-3 ). when the osctune register is modified, the intosc (hf-intosc and mf-intosc) frequency will begin shifting to the new frequency. the oscillator will require some time to stabilize. code execution continues during this shift and there is no indication that the shift has occurred. the lf-intosc oscillator operates independently of the hf-intosc or the mf-intosc source. any changes in the hf-intosc or the mf-intosc source, across voltage and temperature, are not necessarily reflected by changes in lf-intosc or vice versa. the frequency of lf-intosc is not affected by osctune. 3.6.4 intosc frequency drift the intosc frequency may drift as v dd or tempera- ture changes, and can affect the controller operation in a variety of ways. it is possible to adjust the intosc frequency by modifying the value in the osctune register. depending on the device, this may have no effect on the lf-intosc clock source frequency. tuning intosc requires knowing when to make the adjustment, in which direction it should be made, and in some cases, how large a change is needed. three compensation techniques are shown here. 3.6.4.1 compensating with the eusart an adjustment may be required when the eusart begins to generate framing errors or receives data with errors while in asynchronous mode. framing errors indi- cate that the device clock frequency is too high. to adjust for this, decrement the value in osctune to reduce the clock frequency. on the other hand, errors in data may suggest that the clock speed is too low. to compensate, increment osctune to increase the clock frequency. 3.6.4.2 compensating with the timers this technique compares device clock speed to some reference clock. two timers may be used; one timer is clocked by the peripheral clock, while the other is clocked by a fixed reference source, such as the sosc oscillator. both timers are cleared, but the timer clocked by the reference source generates interrupts. when an inter- rupt occurs, the internally clocked timer is read and both timers are cleared. if the internally clocked timer value is much greater than expected, then the internal oscillator block is running too fast. to adjust for this, decrement the osctune register. 3.6.4.3 compensating with the ccp module in capture mode a ccp module can use free-running timer1 (or timer3), clocked by the internal oscillator block and an external event with a known period (i.e., ac power frequency). the time of the first event is captured in the ccprxh:ccprxl registers and is recorded for use later. when the second event causes a capture, the time of the first event is subtracted from the time of the second event. since the period of the external event is known, the time difference between events can be calculated. if the measured time is much greater than the calculated time, the internal oscillator block is running too fast. to compensate, decrement the osctune register. if the measured time is much less than the calculated time, the internal oscillator block is running too slow. to compensate, increment the osctune register. 3.7 reference clock output in addition to the f osc /4 clock output, in certain oscillator modes, the device clock in the pic18f87k22 family can also be configured to provide a reference clock output signal to a port pin. this feature is avail- able in all oscillator configurations and allows the user to select a greater range of clock submultiples to drive external devices in the application. this reference clock output is controlled by the refocon register ( register 3-4 ). setting the roon bit (refocon<7>) makes the clock signal available on the refo (re3) pin. the rodiv<3:0> bits enable the selection of 16 different clock divider options. the rosslp and rosel bits (refocon<5:4>) con- trol the availability of the reference output during sleep mode. the rosel bit determines if the oscillator on osc1 and osc2, or the current system clock source, is used for the reference clock output. the rosslp bit determines if the reference source is available on re3 when the device is in sleep mode. to use the reference clock output in sleep mode, both the rosslp and rosel bits must be set. the device clock must also be configured for an ec or hs mode. if not, the oscillator on osc1 and osc2 will be powered down when the device enters sleep mode. clearing the rosel bit allows the reference output frequency to change as the system clock changes during any clock switches. downloaded from: http:///
pic18f87k22 family ds39960d-page 54 ? 2009-2011 microchip technology inc. register 3-4: refocon: reference oscillator control register r/w-0 u-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 roon rosslp rosel ( 1 ) rodiv3 rodiv2 rodiv1 rodiv0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 roon: reference oscillator output enable bit 1 = reference oscillator output is available on refo pin 0 = reference oscillator output is disabled bit 6 unimplemented: read as 0 bit 5 rosslp: reference oscillator output stop in sleep bit 1 = reference oscillator continues to run in sleep 0 = reference oscillator is disabled in sleep bit 4 rosel: reference oscillator source select bit ( 1 ) 1 = primary oscillator (ec or hs) is used as the base clock 0 = system clock is used as the base clock; base clock reflects any clock switching of the device bit 3-0 rodiv<3:0>: reference oscillator divisor select bits 1111 = base clock value divided by 32,768 1110 = base clock value divided by 16,384 1101 = base clock value divided by 8,192 1100 = base clock value divided by 4,096 1011 = base clock value divided by 2,048 1010 = base clock value divided by 1,024 1001 = base clock value divided by 512 1000 = base clock value divided by 256 0111 = base clock value divided by 128 0110 = base clock value divided by 64 0101 = base clock value divided by 32 0100 = base clock value divided by 16 0011 = base clock value divided by 8 0010 = base clock value divided by 4 0001 = base clock value divided by 2 0000 = base clock value note 1: for rosel (revocon<4>), the primary oscillator is available only when configure d as the default via the fosc settings. this is regardless of whether the device is in sleep mode. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 55 pic18f87k22 family 3.8 effects of power-managed modes on the various clock sources when pri_idle mode is selected, the designated pri- mary oscillator continues to run without interruption. for all other power-managed modes, the oscillator using the osc1 pin is disabled. the osc1 pin (and osc2 pin if used by the oscillator) will stop oscillating. in secondary clock modes (sec_run and sec_idle), the sosc oscillator is operating and providing the device clock. the sosc oscillator may also run in all power-managed modes if required to clock sosc. in rc_run and rc_idle modes, the internal oscillator provides the device clock source. the 31 khz lf-intosc output can be used directly to provide the clock and may be enabled to support various special features, regardless of the power-managed mode (see section 28.2 watchdog timer (wdt) through section 28.5 fail-safe clock monitor for more information on wdt, fail-safe clock monitor and two-speed start-up). if sleep mode is selected, all clock sources are stopped. since all the transistor switching currents have been stopped, sleep mode achieves the lowest current consumption of the device (only leakage currents). enabling any on-chip feature that will operate during sleep will increase the current consumed during sleep. the intosc is required to support wdt operation. the sosc oscillator may be operating to support a real-time clock (rtc). other features may be operat- ing that do not require a device clock source (i.e., mssp slave, intx pins and others). peripherals that may add significant current consumption are listed in section 31.2 dc characteristics: power-down and supply current pic18f87k22 family (industrial/ extended) . 3.9 power-up delays power-up delays are controlled by two timers, so that no external reset circuitry is required for most applica- tions. the delays ensure that the device is kept in reset until the device power supply is stable under nor- mal circumstances and the primary clock is operating and stable. for additional information on power-up delays, see section 5.6 power-up timer (pwrt) . the first timer is the power-up timer (pwrt), which provides a fixed delay on a power-up time of about 64 ms (parameter 33 , table 31-13 ); it is always enabled. the second timer is the oscillator start-up timer (ost), intended to keep the chip in reset until the crystal oscillator is stable (hs, xt or lp modes). the ost does this by counting 1,024 oscillator cycles before allowing the oscillator to clock the device. there is a delay of interval, t csd (parameter 38 , table 31-13 ), following por, while the controller becomes ready to execute instructions. table 3-4: osc1 and osc2 pin states in sleep mode oscillator mode osc1 pin osc2 pin ec, ecpll floating, pulled by external clock at logic low (clock/4 output) hs, hspll feedback inverter is disabled at quiescent voltage level feedback inverter is disabled at quiescent voltage level intosc, intpll1/2 i/o pin, ra6, direction is controlled by trisa<6> i/o pin, ra6, direction is controlled by trisa<7> note: see section 5.0 reset for time-outs due to sleep and mclr reset. downloaded from: http:///
pic18f87k22 family ds39960d-page 56 ? 2009-2011 microchip technology inc. notes: downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 57 pic18f87k22 family 4.0 power-managed modes the pic18f87k22 family of devices offers a total of seven operating modes for more efficient power man- agement. these modes provide a variety of options for selective power conservation in applications where resources may be limited (such as battery-powered devices). there are three categories of power-managed mode: run modes idle modes sleep mode there is an ultra low-power wake-up (ulpwu) for waking from the sleep mode. these categories define which portions of the device are clocked, and sometimes, at what speed. the run and idle modes may use any of the three available clock sources (primary, secondary or internal oscillator block). the sleep mode does not use a clock source. the ulpwu mode, on the ra0 pin, enables a slow fall- ing voltage to generate a wake-up, even from sleep, without excess current consumption. (see section 4.7 ultra low-power wake-up .) the power-managed modes include several power- saving features offered on previous pic ? devices. one is the clock switching feature, offered in other pic18 devices. this feature allows the controller to use the sosc oscillator instead of the primary one. another power-saving feature is sleep mode, offered by all pic devices, where all device clocks are stopped. 4.1 selecting power-managed modes selecting a power-managed mode requires two decisions: will the cpu be clocked or not what will be the clock source the idlen bit (osccon<7>) controls cpu clocking, while the scs<1:0> bits (osccon<1:0>) select the clock source. the individual modes, bit settings, clock sources and affected modules are summarized in tab l e 4 - 1 . 4.1.1 clock sources the scs<1:0> bits select one of three clock sources for power-managed modes. those sources are: the primary clock as defined by the fosc<3:0> configuration bits the secondary clock (the sosc oscillator) the internal oscillator block (for lf-intosc modes) 4.1.2 entering power-managed modes switching from one power-managed mode to another begins by loading the osccon register. the scs<1:0> bits select the clock source and determine which run or idle mode is used. changing these bits causes an immediate switch to the new clock source, assuming that it is running. the switch may also be subject to clock transition delays. these considerations are discussed in section 4.1.3 clock transitions and status indicators and subsequent sections. entering the power-managed idle or sleep modes is triggered by the execution of a sleep instruction. the actual mode that results depends on the status of the idlen bit. depending on the current and impending mode, a change to a power-managed mode does not always require setting all of the previously discussed bits. many transitions can be done by changing the oscillator select bits, or changing the idlen bit, prior to issuing a sleep instruction. if the idlen bit is already configured as desired, it may only be necessary to perform a sleep instruction to switch to the desired mode. table 4-1: power- managed modes mode osccon bits module clocking available clock and oscillator source idlen<7> ( 1 ) scs<1:0> cpu peripherals sleep 0 n/a off off none C all clocks are disabled pri_run n/a 00 clocked clocked primary C xt, lp, hs, ec, rc and pll modes. this is the normal, full-power execution mode. sec_run n/a 01 clocked clocked secondary C sosc oscillator rc_run n/a 1x clocked clocked internal oscillator block ( 2 ) pri_idle 10 0 off clocked primary C lp, xt, hs, rc, ec sec_idle 10 1 off clocked secondary C sosc oscillator rc_idle 11 x off clocked internal oscillator block ( 2 ) note 1: idlen reflects its value when the sleep instruction is executed. 2: includes intosc (hf-intosc and mg-intosc) and intosc postscaler, as well as the lf-intosc source. downloaded from: http:///
pic18f87k22 family ds39960d-page 58 ? 2009-2011 microchip technology inc. 4.1.3 clock transitions and status indicators the length of the transition between clock sources is the sum of two cycles of the old clock source and three to four cycles of the new clock source. this for- mula assumes that the new clock source is stable. the hf-intosc and mf-intosc are termed as intosc in this chapter. three bits indicate the current clock source and its status, as shown in ta bl e 4 - 2 . the three bits are: osts (osccon<3>) hfiofs (osccon<2>) soscrun (osccon2<6>) when the osts bit is set, the primary clock is providing the device clock. when the hfiofs or mfiofs bit is set, the intosc output is providing a stable 16 mhz clock source to a divider that actually drives the device clock. when the soscrun bit is set, the sosc oscil- lator is providing the clock. if none of these bits are set, either the lf-intosc clock source is clocking the device or the intosc source is not yet stable. if the internal oscillator block is configured as the primary clock source by the fosc<3:0> configuration bits (config1h<3:0>), then the osts and hfiofs or mfiofs bits can be set when in pri_run or pri_idle modes. this indicates that the primary clock (intosc output) is generating a stable 16 mhz output. entering another intosc power-managed mode at the same frequency would clear the osts bit. 4.1.4 multiple sleep commands the power-managed mode that is invoked with the sleep instruction is determined by the setting of the idlen bit at the time the instruction is executed. if another sleep instruction is executed, the device will enter the power-managed mode specified by idlen at that time. if idlen has changed, the device will enter the new power-managed mode specified by the new setting. 4.2 run modes in the run modes, clocks to both the core and peripherals are active. the difference between these modes is the clock source. 4.2.1 pri_run mode the pri_run mode is the normal, full-power execu- tion mode of the microcontroller. this is also the default mode upon a device reset, unless two-speed start-up is enabled. (for details, see section 28.4 two-speed start-up .) in this mode, the osts bit is set. the hfiofs or mfiofs bit may be set if the internal oscillator block is the primary clock source. (see section 3.2 control registers .) 4.2.2 sec_run mode the sec_run mode is the compatible mode to the clock-switching feature offered in other pic18 devices. in this mode, the cpu and peripherals are clocked from the sosc oscillator. this enables lower power consumption while retaining a high-accuracy clock source. sec_run mode is entered by setting the scs<1:0> bits to 01 . the device clock source is switched to the sosc oscillator (see figure 4-1 ), the primary oscillator is shut down, the soscrun bit (osccon2<6>) is set and the osts bit is cleared. on transitions from sec_run mode to pri_run mode, the peripherals and cpu continue to be clocked from the sosc oscillator while the primary clock is started. when the primary clock becomes ready, a clock switch back to the primary clock occurs (see figure 4-2 ). when the clock switch is complete, the soscrun bit is cleared, the osts bit is set and the primary clock is providing the clock. the idlen and scs bits are not affected by the wake-up and the sosc oscillator continues to run. table 4-2: system clock indicator main clock source osts hfiofs or mfiofs soscrun primary oscillator 10 0 intosc (hf-intosc or mf-intosc) 01 0 secondary oscillator 00 1 mf-intosc or hf-intosc as primary clock source 11 0 lf-intosc is running or intosc is not yet stable 00 0 note 1: caution should be used when modifying a single ircf bit. at a lower v dd , it is possible to select a higher clock speed than is supportable by that v dd . improper device operation may result if the v dd / f osc specifications are violated. 2: executing a sleep instruction does not necessarily place the device into sleep mode. it acts as the trigger to place the controller into either the sleep mode or one of the idle modes, depending on the setting of the idlen bit. note: the sosc oscillator can be enabled by setting the soscgo bit (osccon2<3>). if this bit is set, the clock switch to the sec_run mode can switch immediately once scs<1:0> are set to 01 . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 59 pic18f87k22 family figure 4-1: transition timing for entry to sec_run mode figure 4-2: transition timing from sec_run mode to pri_run mode (hspll) q4 q3 q2 osc1 peripheral program q1 sosci q1 counter clock cpu clock pc + 2 pc 123 n - 1n clock transition (1) q4 q3 q2 q1 q3 q2 pc + 4 note 1: clock transition typically occurs within 2-4 t osc . q1 q3 q4 osc1 peripheral program pc sosc pll clock q1 pc + 4 q2 output q3 q4 q1 cpu clock pc + 2 clock counter q2 q2 q3 note 1: t ost = 1024 t osc ; t pll = 2 ms (approx). these intervals are not shown to scale. 2: clock transition typically occurs within 2-4 t osc . scs<1:0> bits changed t pll (1) 12 n-1n clock osts bit set transition (2) t ost (1) downloaded from: http:///
pic18f87k22 family ds39960d-page 60 ? 2009-2011 microchip technology inc. 4.2.3 rc_run mode in rc_run mode, the cpu and peripherals are clocked from the internal oscillator block using the intosc multiplexer. in this mode, the primary clock is shut down. when using the lf-intosc source, this mode provides the best power conservation of all the run modes, while still executing code. it works well for user applications which are not highly timing-sensitive or do not require high-speed clocks at all times. if the primary clock source is the internal oscillator block C either lf-intosc or intosc (mf-intosc or hf-intosc) C there are no distinguishable differences between the pri_run and rc_run modes during execution. entering or exiting rc_run mode, how- ever, causes a clock switch delay. therefore, if the primary clock source is the internal oscillator block, using rc_run mode is not recommended. this mode is entered by setting the scs1 bit to 1 . to maintain software compatibility with future devices, it is recommended that the scs0 bit also be cleared, even though the bit is ignored. when the clock source is switched to the intosc multiplexer (see figure 4-3 ), the primary oscillator is shut down and the osts bit is cleared. the ircf bits may be modified at any time to immediately change the clock speed. if the ircf bits and the intsrc bit are all clear, the intosc output (hf-intosc/mf-intosc) is not enabled and the hfiofs and mfiofs bits will remain clear. there will be no indication of the current clock source. the lf-intosc source is providing the device clocks. if the ircf bits are changed from all clear (thus, enabling the intosc output), or if intsrc or mfiosel is set, the hfiofs or mfiofs bit is set after the intosc output becomes stable. for details, see table 4-3 . table 4-3: internal oscillator frequency stability bits note: caution should be used when modifying a single ircf bit. at a lower v dd , it is possible to select a higher clock speed than is supportable by that v dd . improper device operation may result if the v dd / f osc specifications are violated. ircf<2:0> intsrc mfiosel status of mfiofs or hfiofs when intosc is stable 000 0 x mfiofs = 0 , hfiofs = 0 and clock source is lf-intosc 000 1 0 mfiofs = 0 , hfiofs = 1 and clock source is hf-intosc 000 1 1 mfiofs = 1 , hfiofs = 0 and clock source is mf-intosc non-zero x0 mfiofs = 0 , hfiofs = 1 and clock source is hf-intosc non-zero x1 mfiofs = 1 , hfiofs = 0 and clock source is mf-intosc downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 61 pic18f87k22 family clocks to the device continue while the intosc source stabilizes after an interval of t iobst (parameter 39 , table 31-13 ). if the ircf bits were previously at a non-zero value, or if intsrc was set before setting scs1 and the intosc source was already stable, the hfiofs or mfiofs bit will remain set. on transitions from rc_run mode to pri_run mode, the device continues to be clocked from the intosc multiplexer while the primary clock is started. when the primary clock becomes ready, a clock switch to the primary clock occurs (see figure 4-4 ). when the clock switch is complete, the hfiofs or mfiofs bit is cleared, the osts bit is set and the primary clock is providing the device clock. the idlen and scs bits are not affected by the switch. the lf-intosc source will continue to run if either the wdt or the fail-safe clock monitor is enabled. figure 4-3: transition timing to rc_run mode figure 4-4: transition timing fr om rc_run mode to pri_run mode q4 q3 q2 osc1 peripheral program q1 lf-intosc q1 counter clock cpu clock pc + 2 pc 123 n - 1n clock transition (1) q4 q3 q2 q1 q3 q2 pc + 4 note 1: clock transition typically occurs within 2-4 t osc . q1 q3 q4 osc1 peripheral program pc intosc pll clock q1 pc + 4 q2 output q3 q4 q1 cpu clock pc + 2 clock counter q2 q2 q3 note 1: t ost = 1024 t osc ; t pll = 2 ms (approx). these intervals are not shown to scale. 2: clock transition typically occurs within 2-4 t osc . scs<1:0> bits changed t pll (1) 12 n-1n clock osts bit set transition (2) multiplexer t ost (1) downloaded from: http:///
pic18f87k22 family ds39960d-page 62 ? 2009-2011 microchip technology inc. 4.3 sleep mode the power-managed sleep mode in the pic18f87k22 family of devices is identical to the legacy sleep mode offered in all other pic devices. it is entered by clearing the idlen bit (the default state on device reset) and executing the sleep instruction. this shuts down the selected oscillator ( figure 4-5 ). all clock source status bits are cleared. entering sleep mode from any other mode does not require a clock switch. this is because no clocks are needed once the controller has entered sleep. if the wdt is selected, the lf-intosc source will continue to operate. if the sosc oscillator is enabled, it will also continue to run. when a wake event occurs in sleep mode (by interrupt, reset or wdt time-out), the device will not be clocked until the clock source selected by the scs<1:0> bits becomes ready (see figure 4-6 ). alternately, the device will be clocked from the internal oscillator block if either the two-speed start-up or the fail-safe clock monitor is enabled (see section 28.0 special features of the cpu ). in either case, the osts bit is set when the primary clock is providing the device clocks. the idlen and scs bits are not affected by the wake-up. 4.4 idle modes the idle modes allow the controllers cpu to be selectively shut down while the peripherals continue to operate. selecting a particular idle mode allows users to further manage power consumption. if the idlen bit is set to a 1 when a sleep instruction is executed, the peripherals will be clocked from the clock source selected using the scs<1:0> bits. the cpu, however, will not be clocked. the clock source status bits are not affected. this approach is a quick method to switch from a given run mode to its corresponding idle mode. if the wdt is selected, the lf-intosc source will continue to operate. if the sosc oscillator is enabled, it will also continue to run. since the cpu is not executing instructions, the only exits from any of the idle modes are by interrupt, wdt time-out or a reset. when a wake event occurs, cpu execution is delayed by an interval of t csd (parameter 38 , table 31-13 ) while it becomes ready to execute code. when the cpu begins executing code, it resumes with the same clock source for the current idle mode. for example, when waking from rc_idle mode, the internal oscillator block will clock the cpu and peripherals (in other words, rc_run mode). the idlen and scs bits are not affected by the wake-up. while in any idle mode or sleep mode, a wdt time- out will result in a wdt wake-up to the run mode currently specified by the scs<1:0> bits. figure 4-5: transition timi ng for entry to sleep mode figure 4-6: transition timing for wake from sleep (hspll) q4 q3 q2 osc1 peripheral sleep program q1 q1 counter clock cpu clock pc + 2 pc q3 q4 q1 q2 osc1 peripheral program pc pll clock q3 q4 output cpu clock q1 q2 q3 q4 q1 q2 clock counter pc + 6 pc + 4 q1 q2 q3 q4 wake event note 1: t ost = 1024 t osc ; t pll = 2 ms (approx). these intervals are not shown to scale. t ost (1) t pll (1) osts bit set pc + 2 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 63 pic18f87k22 family 4.4.1 pri_idle mode this mode is unique among the three low-power idle modes, in that it does not disable the primary device clock. for timing-sensitive applications, this allows for the fastest resumption of device operation with its more accurate, primary clock source, since the clock source does not have to warm-up or transition from another oscillator. pri_idle mode is entered from pri_run mode by setting the idlen bit and executing a sleep instruc- tion. if the device is in another run mode, set idlen first, then clear the scs bits and execute sleep . although the cpu is disabled, the peripherals continue to be clocked from the primary clock source specified by the fosc<3:0> configuration bits. the osts bit remains set (see figure 4-7 ). when a wake event occurs, the cpu is clocked from the primary clock source. a delay of interval, t csd (parameter 39 , table 31-13 ), is required between the wake event and the start of code execution. this is required to allow the cpu to become ready to execute instructions. after the wake-up, the osts bit remains set. the idlen and scs bits are not affected by the wake-up (see figure 4-8 ). 4.4.2 sec_idle mode in sec_idle mode, the cpu is disabled but the peripherals continue to be clocked from the sosc oscillator. this mode is entered from sec_run by set- ting the idlen bit and executing a sleep instruction. if the device is in another run mode, set the idlen bit first, then set the scs<1:0> bits to 01 and execute sleep . when the clock source is switched to the sosc oscillator, the primary oscillator is shut down, the osts bit is cleared and the soscrun bit is set. when a wake event occurs, the peripherals continue to be clocked from the sosc oscillator. after an interval of t csd following the wake event, the cpu begins executing code being clocked by the sosc oscillator. the idlen and scs bits are not affected by the wake- up and the sosc oscillator continues to run (see figure 4-8 ). figure 4-7: transition timing for entry to idle mode figure 4-8: transition timing for wake from idle to run mode q1 peripheral program pc pc + 2 osc1 q3 q4 q1 cpu clock clock counter q2 osc1 peripheral program pc cpu clock q1 q3 q4 clock counter q2 wake event t csd downloaded from: http:///
pic18f87k22 family ds39960d-page 64 ? 2009-2011 microchip technology inc. 4.4.3 rc_idle mode in rc_idle mode, the cpu is disabled but the periph- erals continue to be clocked from the internal oscillator block using the intosc multiplexer. this mode provides controllable power conservation during idle periods. from rc_run, this mode is entered by setting the idlen bit and executing a sleep instruction. if the device is in another run mode, first set idlen, then set the scs1 bit and execute sleep . to maintain software compatibility with future devices, it is recommended that scs0 also be cleared, though its value is ignored. the intosc multiplexer may be used to select a higher clock frequency by modifying the ircf bits before executing the sleep instruction. when the clock source is switched to the intosc multiplexer, the primary oscillator is shut down and the osts bit is cleared. if the ircf bits are set to any non-zero value, or the intsrc/mfiosel bit is set, the intosc output is enabled. the hfiofs/mfiofs bits become set, after the intosc output becomes stable, after an interval of t iobst (parameter 38 , table 31-13 ). (for information on the hfiofs/mfiofs bits, see table 4-3 .) clocks to the peripherals continue while the intosc source stabilizes. the hfiofs/mfiofs bits will remain set if the ircf bits were previously at a non- zero value or if intsrc was set before the sleep instruction was executed and the intosc source was already stable. if the ircf bits and intsrc are all clear, the intosc output will not be enabled, the hfiofs/mfiofs bits will remain clear and there will be no indication of the current clock source. when a wake event occurs, the peripherals continue to be clocked from the intosc multiplexer. after a delay of t csd (parameter 38 , table 31-13 ) following the wake event, the cpu begins executing code clocked by the intosc multiplexer. the idlen and scs bits are not affected by the wake-up. the intrc source will continue to run if either the wdt or the fail-safe clock monitor is enabled. 4.5 selective peripheral module control idle mode allows users to substantially reduce power consumption by stopping the cpu clock. even so, peripheral modules still remain clocked, and thus, consume power. there may be cases where the appli- cation needs what this mode does not provide: the allocation of power resources to the cpu processing with minimal power consumption from the peripherals. pic18f87k22 family devices address this requirement by allowing peripheral modules to be selectively disabled, reducing or eliminating their power consumption. this can be done with two control bits: peripheral enable bit, generically named xxxen C located in the respective modules main control register peripheral module disable (pmd) bit, generically named, xxxmd C located in one of the pmdx control registers (pmd0, pmd1, pmd2 or pmd3) disabling a module by clearing its xxxen bit disables the modules functionality, but leaves its registers available to be read and written to. this reduces power consumption, but not by as much as the second approach. most peripheral modules have an enable bit. in contrast, setting the pmd bit for a module disables all clock sources to that module, reducing its power consumption to an absolute minimum. in this state, the control and status registers associated with the periph- eral are also disabled, so writes to those registers have no effect and read values are invalid. many peripheral modules have a corresponding pmd bit. there are four pmd registers in the pic18f87k22 family devices: pmd0, pmd1, pmd2 and pmd3. these registers have bits associated with each module for disabling or enabling a particular peripheral. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 65 pic18f87k22 family register 4-1: pmd3: peripheral module disable register 3 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 ccp10md ( 1 ) ccp9md ( 1 ) ccp8md ccp7md ccp6md ccp5md ccp4md tmr12md ( 1 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 ccp10md: pmd ccp10 enable/disable bit ( 1 ) 1 = peripheral module disable (pmd) is enabled for ccp10, disabling all of its clock sources 0 = pmd is disabled for ccp10 bit 6 ccp9md: pmd ccp9 enable/disable bit ( 1 ) 1 = peripheral module disable (pmd) is enabled for ccp9, disabling all of its clock sources 0 = pmd is disabled for ccp9 bit 5 ccp8md: pmd ccp8 enable/disable bit 1 = peripheral module disable (pmd) is enabled for ccp8, disabling all of its clock sources 0 = pmd is disabled for ccp8 bit 4 ccp7md: pmd ccp7 enable/disable bit 1 = peripheral module disable (pmd) is enabled for ccp7, disabling all of its clock sources 0 = pmd is disabled for ccp7 bit 3 ccp6md: pmd ccp6 enable/disable bit 1 = peripheral module disable (pmd) is enabled for ccp6, disabling all of its clock sources 0 = pmd is disabled for ccp6 bit 2 ccp5md: pmd ccp5 enable/disable bit 1 = peripheral module disable (pmd) is enabled for ccp5, disabling all of its clock sources 0 = pmd is disabled for ccp5 bit 1 ccp4md: pmd ccp4 enable/disable bit 1 = peripheral module disable (pmd) is enabled for ccp4, disabling all of its clock sources 0 = pmd is disabled for ccp4 bit 0 tmr12md: tmr12md disable bit ( 1 ) 1 = pmd is enabled and all tmr12md clock sources are disabled 0 = pmd is disabled and tmr12md is enabled note 1: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
pic18f87k22 family ds39960d-page 66 ? 2009-2011 microchip technology inc. register 4-2: pmd2: peripheral module disable register 2 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 tmr10md ( 1 ) tmr8md tmr7md ( 1 ) tmr6md tmr5md cmp3md cmp2md cmp1md bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 tmr10md: tmr10md disable bit ( 1 ) 1 = peripheral module disable (pmd) is enabled and all tmr10md clock sources are disabled 0 = pmd is disabled and tmr10md is enabled bit 6 tmr8md: tmr8md disable bit 1 = pmd is enabled and all tmr8md clock sources are disabled 0 = pmd is disabled and tmr8md is enabled bit 5 tmr7md: tmr7md disable bit ( 1 ) 1 = pmd is enabled and all tmr7md clock sources are disabled 0 = pmd is disabled and tmr7md is enabled bit 4 tmr6md: tmr6md disable bit 1 = pmd is enabled and all tmr6md clock sources are disabled 0 = pmd is disabled and tmr6md is enabled bit 3 tmr5md: tmr5md disable bit 1 = pmd is enabled and all tmr5md clock sources are disabled 0 = pmd is disabled and tmr5md is enabled bit 2 cmp3md: pmd comparator 3 enable/disable bit 1 = pmd is enabled for comparator 3, disabling all of its clock sources 0 = pmd is disabled for comparator 3 bit 1 cmp2md: pmd comparator 3 enable/disable bit 1 = pmd is enabled for comparator 2, disabling all of its clock sources 0 = pmd is disabled for comparator 2 bit 0 cmp1md: pmd comparator 3 enable/disable bit 1 = pmd is enabled for comparator 1, disabling all of its clock sources 0 = pmd is disabled for comparator 1 note 1: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 67 pic18f87k22 family register 4-3: pmd1: peripheral module disable register 1 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 pspmd ctmumd rtccmd ( 1 ) tmr4md tmr3md tmr2md tmr1md embmd bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 pspmd: peripheral module disable (pmd) psp enable/disable bit 1 = pmd is enabled for psp, disabling all of its clock sources 0 = pmd is disabled for psp bit 6 ctmumd: pmd ctmu enable/disable bit 1 = pmd is enabled for ctmu, disabling all of its clock sources 0 = pmd is disabled for ctmu bit 5 rtccmd: pmd rtcc enable/disable bit ( 1 ) 1 = pmd is enabled for rtcc, disabling all of its clock sources 0 = pmd is disabled for rtcc bit 4 tmr4md: tmr4md disable bit 1 = pmd is enabled and all tmr4md clock sources are disabled 0 = pmd is disabled and tmr4md is enabled bit 3 tmr3md: tmr3md disable bit 1 = pmd is enabled and all tmr3md clock sources are disabled 0 = pmd is disabled and tmr3md is enabled bit 2 tmr2md: tmr2md disable bit 1 = pmd is enabled and all tmr2md clock sources are disabled 0 = pmd is disabled and tmr2md is enabled bit 1 tmr1md: tmr1md disable bit 1 = pmd is enabled and all tmr1md clock sources are disabled 0 = pmd is disabled and tmr1md is enabled bit 0 embmd: pmd emb enable/disable bit 1 = pmd is enabled for emb, disabling all of its clock sources 0 = pmd is disabled for emb note 1: rtccmd can only be set to 1 after an eecon2 unlock sequence. refer to section 18.0 real-time clock and calendar (rtcc) for the unlock sequence ( example 18-1 ). downloaded from: http:///
pic18f87k22 family ds39960d-page 68 ? 2009-2011 microchip technology inc. register 4-4: pmd0: peripheral module disable register 0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 ccp3md: pmd eccp3 enable/disable bit 1 = peripheral module disable (pmd) is enabled for eccp3, disabling all of its clock sources 0 = pmd is disabled for eccp3 bit 6 ccp2md: pmd eccp2 enable/disable bit 1 = pmd is enabled for eccp2, disabling all of its clock sources 0 = pmd is disabled for eccp2 bit 5 ccp1md: pmd eccp1 enable/disable bit 1 = pmd is enabled for eccp1, disabling all of its clock sources 0 = pmd is disabled for eccp1 bit 4 uart2md: pmd uart2 enable/disable bit 1 = pmd is enabled for uart2, disabling all of its clock sources 0 = pmd is disabled for uart2 bit 3 uart1md: pmd uart1 enable/disable bit 1 = pmd is enabled for uart1, disabling all of its clock sources 0 = pmd is disabled for uart1 bit 2 ssp2md: pmd mssp2 enable/disable bit 1 = pmd is enabled for mssp2, disabling all of its clock sources 0 = pmd is disabled for mssp2 bit 1 ssp1md: pmd mssp1 enable/disable bit 1 = pmd is enabled for mssp1, disabling all of its clock sources 0 = pmd is disabled for mssp1 bit 0 adcmd: pmd analog/digital converter pmd enable/disable bit 1 = pmd is enabled for the analog/digital converter, disabling all of its clock sources 0 = pmd is disabled for the analog/digital converter downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 69 pic18f87k22 family 4.6 exiting idle and sleep modes an exit from sleep mode or any of the idle modes is triggered by an interrupt, a reset or a wdt time-out. this section discusses the triggers that cause exits from power-managed modes. the clocking subsystem actions are discussed in each of the power-managed modes (see section 4.2 run modes , section 4.3 sleep mode and section 4.4 idle modes ). 4.6.1 exit by interrupt any of the available interrupt sources can cause the device to exit from an idle mode or sleep mode to a run mode. to enable this functionality, an interrupt source must be enabled by setting its enable bit in one of the intconx or piex registers. the exit sequence is initiated when the corresponding interrupt flag bit is set. on all exits from idle or sleep modes by interrupt, code execution branches to the interrupt vector if the gie/ gieh bit (intcon<7>) is set. otherwise, code execu- tion continues or resumes without branching (see section 11.0 interrupts ). 4.6.2 exit by wdt time-out a wdt time-out will cause different actions depending on which power-managed mode the device is in when the time-out occurs. if the device is not executing code (all idle modes and sleep mode), the time-out will result in an exit from the power-managed mode (see section 4.2 run modes and section 4.3 sleep mode ). if the device is executing code (all run modes), the time-out will result in a wdt reset (see section 28.2 watchdog timer (wdt) ). executing a sleep or clrwdt instruction clears the wdt timer and postscaler, loses the currently selected clock source (if the fail-safe clock monitor is enabled) and modifies the ircf bits in the osccon register (if the internal oscillator block is the device clock source). 4.6.3 exit by reset normally, the device is held in reset by the oscillator start-up timer (ost) until the primary clock becomes ready. at that time, the osts bit is set and the device begins executing code. if the internal oscillator block is the new clock source, the hfiofs/mfiofs bits are set instead. the exit delay time from reset to the start of code execution depends on both the clock sources before and after the wake-up, and the type of oscillator if the new clock source is the primary clock. exit delays are summarized in ta b l e 4 - 4 . code execution can begin before the primary clock becomes ready. if either the two-speed start-up (see section 28.4 two-speed start-up ) or fail-safe clock monitor (see section 28.5 fail-safe clock monitor ) is enabled, the device may begin execution as soon as the reset source has cleared. execution is clocked by the intosc multiplexer driven by the internal oscillator block. execution is clocked by the internal oscillator block until either the primary clock becomes ready or a power-managed mode is entered before the primary clock becomes ready; the primary clock is then shut down. 4.6.4 exit without an oscillator start-up delay certain exits from power-managed modes do not invoke the ost at all. the two cases are: when in pri_idle mode, where the primary clock source is not stopped when the primary clock source is not any of the lp, xt, hs or hspll modes in these instances, the primary clock source either does not require an oscillator start-up delay, since it is already running (pri_idle), or normally does not require an oscillator start-up delay (rc, ec and intio oscillator modes). however, a fixed delay of interval, t csd , following the wake event, is still required when leaving sleep and idle modes to allow the cpu to prepare for execution. instruction execution resumes on the first clock cycle following this delay. downloaded from: http:///
pic18f87k22 family ds39960d-page 70 ? 2009-2011 microchip technology inc. 4.7 ultra low-power wake-up the ultra low-power wake-up (ulpwu) on pin, ra0, allows a slow falling voltage to generate an interrupt without excess current consumption. to use this feature: 1. charge the capacitor on ra0 by configuring the ra0 pin to an output and setting it to 1 . 2. stop charging the capacitor by configuring ra0 as an input. 3. discharge the capacitor by setting the ulpen and ulpsink bits in the wdtcon register. 4. configure sleep mode. 5. enter sleep mode. when the voltage on ra0 drops below v il , the device wakes up and executes the next instruction. this feature provides a low-power technique for periodically waking up the device from sleep mode. the time-out is dependent on the discharge time of the rc circuit on ra0. when the ulpwu module wakes the device from sleep mode, the ulplvl bit (wdtcon<5>) is set. software can check this bit upon wake-up to determine the wake-up source. see example 4-1 for initializing the ulpwu module. example 4-1: ultra low-power wake-up initialization a series resistor, between ra0 and the external capac- itor, provides overcurrent protection for the ra0/an0/ ulpwu pin and enables software calibration of the time-out (see figure 4-9 ). figure 4-9: ultra low-power wake-up initialization a timer can be used to measure the charge time and discharge time of the capacitor. the charge time can then be adjusted to provide the desired delay in sleep. this technique compensates for the affects of temper- ature, voltage and component accuracy. the peripheral can also be configured as a simple programmable low-voltage detect (lvd) or temperature sensor. //*************************** //charge the capacitor on ra0 //*************************** trisabits.trisa0 = 0; portabits.ra0 = 1; for(i = 0; i < 10000; i++) nop(); //***************************** //stop charging the capacitor //on ra0 //***************************** trisabits.trisa0 = 1; //***************************** //enable the ultra low power //wakeup module and allow //capacitor discharge //***************************** wdtconbits.ulpen = 1; wdtconbits.ulpsink = 1; //for sleep oscconbits.idlen = 0; //enter sleep mode // sleep(); //for sleep, execution will //resume here note: for more information, see an879, using the microchip ultra low-power wake-up module (ds00879). ra0/an0/ulpwu downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 71 pic18f87k22 family table 4-4: exit delay on wake-up by re set from sleep mode or any idle mode (by clock sources) power-managed mode clock source ( 5 ) exit delay clock ready status bits pri_idle mode lp, xt, hs t csd ( 1 ) osts hspll ec, rc hf-intosc ( 2 ) hfiofs mf-intosc ( 2 ) mfiofs lf-intosc none sec_idle mode sosc t csd ( 1 ) soscrun rc_idle mode hf-intosc ( 2 ) t csd ( 1 ) hfiofs mf-intosc ( 2 ) mfiofs lf-intosc none sleep mode lp, xt, hs t ost ( 3 ) osts hspll t ost + t rc ( 3 ) ec, rc t csd ( 1 ) hf-intosc ( 2 ) t iobst ( 4 ) hfiofs mf-intosc ( 2 ) mfiofs lf-intosc none note 1: t csd (parameter 38 , table 31-13 ) is a required delay when waking from sleep and all idle modes, and runs concurrently with any other required delays (see section 4.4 idle modes ). 2: includes postscaler derived frequencies. on reset, intosc defaults to hf-intosc at 8 mhz. 3: t ost is the oscillator start-up timer (parameter 32 , table 31-13 ). t rc is the pll lock-out timer (parameter f12 , table 31-7 ); it is also designated as t pll . 4: execution continues during t iobst (parameter 39 , table 31-13 ), the intosc stabilization period. 5: the clock source is dependent upon the settings of the scs (osccon<1:0>), ircf (osccon<6:4>) and fosc (config1h<3:0>) bits. downloaded from: http:///
pic18f87k22 family ds39960d-page 72 ? 2009-2011 microchip technology inc. notes: downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 73 pic18f87k22 family 5.0 reset the pic18f87k22 family of devices differentiates between various kinds of reset: a) power-on reset (por) b) mclr reset during normal operation c) mclr reset during power-managed modes d) watchdog timer (wdt) reset (during execution) e) configuration mismatch (cm) reset f) brown-out reset (bor) g) reset instruction h) stack full reset i) stack underflow reset this section discusses resets generated by mclr , por and bor, and covers the operation of the various start-up timers. stack reset events are covered in section 6.1.3.4 stack full and underflow resets . wdt resets are covered in section 28.2 watchdog timer (wdt) . a simplified block diagram of the on-chip reset circuit is shown in figure 5-1 . 5.1 rcon register device reset events are tracked through the rcon register ( register 5-1 ). the lower five bits of the register indicate that a specific reset event has occurred. in most cases, these bits can only be set by the event and must be cleared by the application after the event. the state of these flag bits, taken together, can be read to indicate the type of reset that just occurred. this is described in more detail in section 5.7 reset state of registers . the rcon register also has a control bit for setting interrupt priority (ipen). interrupt priority is discussed in section 11.0 interrupts . figure 5-1: simplified block di agram of on-chip reset circuit external reset mclr v dd wdt time-out v dd rise detect pwrt lf-intosc por pulse chip_reset brown-out reset reset instruction stack pointer stack full/underflow reset sleep ( )_idle 32 ? s pwrt 11-bit ripple counter 66 ms s r q configuration word mismatch downloaded from: http:///
pic18f87k22 family ds39960d-page 74 ? 2009-2011 microchip technology inc. register 5-1: rcon: re set control register r/w-0 r/w-1 r/w-1 r/w-1 r-1 r-1 r/w-0 r/w-0 ipen sboren cm ri to pd por bor bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 ipen: interrupt priority enable bit 1 = enable priority levels on interrupts 0 = disable priority levels on interrupts (pic16cxxx compatibility mode) bit 6 sboren: bor software enable bit if boren<1:0> = 01 : 1 = bor is enabled 0 = bor is disabled if boren<1:0> = 00 , 10 or 11 : bit is disabled and read as 0 . bit 5 cm: configuration mismatch flag bit 1 = a configuration mismatch reset has not occurred 0 = a configuration mismatch reset has occurred (must be set in software after a configura tion mismatch reset occurs) bit 4 ri : reset instruction flag bit 1 = the reset instruction was not executed (set by firmware only) 0 = the reset instruction was executed causing a device reset (must be set in software after a brown-out reset occurs) bit 3 to : watchdog time-out flag bit 1 = set by power-up, clrwdt instruction or sleep instruction 0 = a wdt time-out occurred bit 2 pd : power-down detection flag bit 1 = set by power-up or by the clrwdt instruction 0 = set by execution of the sleep instruction bit 1 por : power-on reset status bit 1 = a power-on reset has not occurred (set by firmware only) 0 = a power-on reset occurred (must be set in software after a power-on reset occurs) bit 0 bor : brown-out reset status bit 1 = a brown-out reset has not occurred (set by firmware only) 0 = a brown-out reset occurred (must be set in software after a brown-out reset occurs) note 1: it is recommended that the por bit be set after a power-on reset has been detected, so that subsequent power-on resets may be detected. 2: brown-out reset is said to have occurred when bor is 0 and por is 1 (assuming that por was set to 1 by software immediately after a power-on reset). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 75 pic18f87k22 family 5.2 master clear (mclr ) the mclr pin provides a method for triggering a hard external reset of the device. a reset is generated by holding the pin low. pic18 extended microcontroller devices have a noise filter in the mclr reset path which detects and ignores small pulses. the mclr pin is not driven low by any internal resets, including the wdt. 5.3 power-on reset (por) a power-on reset condition is generated on-chip whenever v dd rises above a certain threshold. this allows the device to start in the initialized state when v dd is adequate for operation. to take advantage of the por circuitry, tie the mclr pin through a resistor (1 k ? to 10 k ? ) to v dd . this will eliminate external rc components usually needed to create a power-on reset delay. a minimum rise rate for v dd is specified (parameter d004). for a slow rise time, see figure 5-2 . when the device starts normal operation (exiting the reset condition), device operating parameters (such as voltage, frequency and temperature) must be met to ensure operation. if these conditions are not met, the device must be held in reset until the operating conditions are met. power-on reset events are captured by the por bit (rcon<1>). the state of the bit is set to 0 whenever a power-on reset occurs and does not change for any other reset event. por is not reset to 1 by any hardware event. to capture multiple events, the user manually resets the bit to 1 in software following any power-on reset. 5.4 brown-out reset (bor) the pic18f87k22 family has four bor power modes: high-power bor medium power bor low-power bor zero-power bor each power mode is selected by the borpwr<1:0> bits setting (config2l<6:5>). for low, medium and high-power bor, the module monitors the v dd depend- ing on the borv<1:0> setting (config1l<3:2>). a bor event re-arms the power-on reset. it also causes a reset, depending on which of the trip levels has been set: 1.8v, 2v, 2.7v or 3v. bor is enabled by the boren<1:0> bits (config2l<2:1>) and the sboren bit (rcon<6>). typical power consumption is listed as parameter d022a in section 31.0 electrical characteristics . in zero-power bor (zpbormv), the module monitors the v dd voltage and re-arms the por at about 2v. zpbormv does not cause a reset, but re-arms the por. the bor accuracy varies with its power level. the lower the power setting, the less accurate the bor trip levels are. therefore, the high-power bor has the highest accuracy and the low-power bor has the lowest accuracy. the trip levels (bv dd , parameter d005), cur- rent consumption ( section 31.2 dc characteristics: power-down and supply current pic18f87k22 family (industrial/extended) ) and time required below bv dd (t bor , parameter 35) can all be found in section 31.0 electrical characteristics . figure 5-2: external power-on reset circuit (for slow v dd power-up) 5.4.1 detecting bor the bor bit always resets to 0 on any brown-out reset or power-on reset event. this makes it difficult to determine if a brown-out reset event has occurred just by reading the state of bor alone. a more reliable method is to simultaneously check the state of both por and bor . this assumes that the por bit is reset to 1 in software immediately after any power-on reset event. if bor is 0 while por is 1 , it can be reliably assumed that a brown-out reset event has occurred. lp-bor cannot be detected with the bor bit in the rcon register. lp-bor can rearm the por and can cause a power-on reset. note 1: external power-on reset circuit is required only if the v dd power-up slope is too slow. the diode, d, helps discharge the capacitor quickly when v dd powers down. 2: r < 40 k ? is recommended to make sure that the voltage drop across r does not violate the devices electrical specification. 3: r1 ? 1 k ? will limit any current flowing into mclr from external capacitor, c, in the event of mclr /v pp pin breakdown due to electrostatic discharge (esd) or electrical overstress (eos). c r1 r d v dd mclr v dd pic18f87k22 downloaded from: http:///
pic18f87k22 family ds39960d-page 76 ? 2009-2011 microchip technology inc. 5.5 configuration mismatch (cm) the configuration mismatch (cm) reset is designed to detect, and attempt to recover from, random, memory corrupting events. these include electrostatic discharge (esd) events that can cause widespread, single bit changes throughout the device and result in catastrophic failure. in pic18f87k22 family flash devices, the device configuration registers (located in the configuration memory space) are continuously monitored during operation by comparing their values to complimentary shadow registers. if a mismatch is detected between the two sets of registers, a cm reset automatically occurs. these events are captured by the cm bit (rcon<5>). the state of the bit is set to 0 whenever a cm event occurs and does not change for any other reset event. a cm reset behaves similarly to a master clear reset, reset instruction, wdt time-out or stack event reset. as with all hard and power reset events, the device configuration words are reloaded from the flash configuration words in program memory as the device restarts. 5.6 power-up timer (pwrt) pic18f87k22 family devices incorporate an on-chip power-up timer (pwrt) to help regulate the power-on reset process. the pwrt is enabled by setting the pwrten bit (config2l<0>). the main function is to ensure that the device voltage is stable before code is executed. the power-up timer (pwrt) of the pic18f87k22 family devices is a 13-bit counter that uses the lf-intosc source as the clock input. this yields an approximate time interval of 2,048 x 32 ? s=66ms. while the pwrt is counting, the device is held in reset. the power-up time delay depends on the lf-intosc clock and will vary from chip-to-chip due to temperature and process variation. see dc parameter 33 for details. 5.6.1 time-out sequence if enabled, the pwrt time-out is invoked after the por pulse has cleared. the total time-out will vary based on the status of the pwrt. figure 5-3 , figure 5-4 , figure 5-5 and figure 5-6 all depict time-out sequences on power-up with the power-up timer enabled. since the time-outs occur from the por pulse, if mclr is kept low long enough, the pwrt will expire. bringing mclr high will begin execution immediately ( figure 5-5 ). this is useful for testing purposes or for synchronizing more than one pic18 device operating in parallel. figure 5-3: time-out sequ ence on power-up (mclr tied to v dd , v dd rise < t pwrt ) t pwrt v dd mclr internal por pwrt time-out internal reset downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 77 pic18f87k22 family figure 5-4: time-out sequ ence on power-up (mclr not tied to v dd ): case 1 figure 5-5: time-out sequ ence on power-up (mclr not tied to v dd ): case 2 figure 5-6: slow rise time (mclr tied to v dd , v dd rise > t pwrt ) t pwrt v dd mclr internal por pwrt time-out internal reset v dd mclr internal por pwrt time-out internal reset t pwrt v dd mclr internal por pwrt time-out internal reset 0v 1v 3.3v t pwrt downloaded from: http:///
pic18f87k22 family ds39960d-page 78 ? 2009-2011 microchip technology inc. 5.7 reset state of registers most registers are unaffected by a reset. their status is unknown on por and unchanged by all other resets. the other registers are forced to a reset state depending on the type of reset that occurred. most registers are not affected by a wdt wake-up, since this is viewed as the resumption of normal operation. status bits from the rcon register (cm , ri , to , pd , por and bor ) are set or cleared differently in different reset situations, as indicated in tab le 5 -1 . these bits are used in software to determine the nature of the reset. table 5-2 describes the reset states for all of the special function registers. these are categorized by power-on and brown-out resets, master clear and wdt resets, and wdt wake-ups. table 5-1: status bits, their significance and the initialization condition for rcon register condition program counter ( 1 ) rcon register stkptr register cm ri to pd por bor stkful stkunf power-on reset 0000h 111100 0 0 reset instruction 0000h u0uuuu u u brown-out reset 0000h 1111u0 u u configuration mismatch reset 0000h 0uuuuu u u mclr reset during power-managed run modes 0000h uu1uuu u u mclr reset during power- managed idle modes and sleep mode 0000h uu10uu u u mclr reset during full-power execution 0000h uuuuuu u u stack full reset (stvren = 1 ) 0000h uuuuuu 1 u stack underflow reset (stvren = 1 ) 0000h uuuuuu u 1 stack underflow error (not an actual reset, stvren = 0 ) 0000h uuuuuu u 1 wdt time-out during full-power or power-managed run modes 0000h uu0uuu u u wdt time-out during power-managed idle or sleep modes pc + 2 uu00uu u u interrupt exit from power-managed modes pc + 2 uuu0uu u u legend: u = unchanged note 1: when the wake-up is due to an interrupt and the gieh or giel bit is set, the pc is loaded with the interrupt vector (0008h or 0018h). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 79 pic18f87k22 family table 5-2: initialization conditions for all registers register applicable devices power-on reset, brown-out reset mclr resets, wdt reset, reset instruction, stack resets, cm resets wake-up via wdt or interrupt tosu pic18f6xk22 pic18f8xk22 -- -0 0000 - -- 0 0000 ---0 uuuu ( 1 ) tosh pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu ( 1 ) tosl pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu ( 1 ) stkptr pic18f6xk22 pic18f8xk22 00-0 0000 uu-0 0000 uu-u uuuu ( 1 ) pclatu pic18f6xk22 pic18f8xk22 -- -0 0000 - -- 0 0000 ---u uuuu pclath pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu pcl pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 pc + 2 ( 2 ) tblptru pic18f6xk22 pic18f8xk22 -- 00 0000 - -00 0000 --uu uuuu tblptrh pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu tblptrl pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu tablat pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu prodh pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu prodl pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu intcon pic18f6xk22 pic18f8xk22 0000 000x 0000 000u uuuu uuuu ( 3 ) intcon2 pic18f6xk22 pic18f8xk22 1111 1111 1111 1111 uuuu uuuu ( 3 ) intcon3 pic18f6xk22 pic18f8xk22 1100 0000 1100 0000 uuuu uuuu ( 3 ) indf0 pic18f6xk22 pic18f8xk22 n/a n/a n/a postinc0 pic18f6xk22 pic18f8xk22 n/a n/a n/a postdec0 pic18f6xk22 pic18f8xk22 n/a n/a n/a preinc0 pic18f6xk22 pic18f8xk22 n/a n/a n/a plusw0 pic18f6xk22 pic18f8xk22 n/a n/a n/a fsr0h pic18f6xk22 pic18f8xk22 -- -- 0000 - -- - 0000 ---- uuuu fsr0l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu wreg pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu indf1 pic18f6xk22 pic18f8xk22 n/a n/a n/a postinc1 pic18f6xk22 pic18f8xk22 n/a n/a n/a postdec1 pic18f6xk22 pic18f8xk22 n/a n/a n/a preinc1 pic18f6xk22 pic18f8xk22 n/a n/a n/a plusw1 pic18f6xk22 pic18f8xk22 n/a n/a n/a fsr1h pic18f6xk22 pic18f8xk22 -- -- 0000 - -- - 0000 ---- uuuu fsr1l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu bsr pic18f6xk22 pic18f8xk22 -- -- 0000 --- - 0000 ---- uuuu legend: u = unchanged, x = unknown, - = unimplemented bit, read as 0 , q = value depends on condition. shaded cells indicate conditions do not apply for the designated device. note 1: when the wake-up is due to an interrupt, and the giel or gieh bit is set, t he tosu, tosh and tosl are updated with the current value of the pc. the stkptr is modified to point to t he next location in the hardware stack. 2: when the wake-up is due to an interrupt and the giel or gieh bit is set, the pc is loaded with the interrupt vector (0008h or 0018h). 3: one or more bits in the intconx or pirx registers will be affected (to cause wak e-up). 4: see table 5-1 for reset value for specific condition. downloaded from: http:///
pic18f87k22 family ds39960d-page 80 ? 2009-2011 microchip technology inc. indf2 pic18f6xk22 pic18f8xk22 n/a n/a n/a postinc2 pic18f6xk22 pic18f8xk22 n/a n/a n/a postdec2 pic18f6xk22 pic18f8xk22 n/a n/a n/a preinc2 pic18f6xk22 pic18f8xk22 n/a n/a n/a plusw2 pic18f6xk22 pic18f8xk22 n/a n/a n/a fsr2h pic18f6xk22 pic18f8xk22 -- -- xxxx - ---uuuu ---- uuuu fsr2l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu status pic18f6xk22 pic18f8xk22 -- -x xxxx - --u uuuu ---u uuuu tmr0h pic18f6xk22 pic18f8xk22 0000 0000 uuuu uuuu uuuu uuuu tmr0l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu t0con pic18f6xk22 pic18f8xk22 1111 1111 1111 1111 uuuu uuuu spbrgh1 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu osccon pic18f6xk22 pic18f8xk22 0110 q000 0110 q000 uuuu quuu ipr5 pic18f65k22 pic18f85k22 ---1 -111 ---1 -111 ---u -uuu ipr5 pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 1000 0000 1000 0000 uuuu uuuu wdtcon pic18f6xk22 pic18f8xk22 0-x0 -000 0-x0 -000 u-uu -uuu rcon pic18f6xk22 pic18f8xk22 0111 11qq 0uqq qquu uuuu qquu tmr1h pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu tmr1l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu t1con pic18f6xk22 pic18f8xk22 0000 0000 uuuu uuuu uuuu uuuu tmr2 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu pr2 pic18f6xk22 pic18f8xk22 1111 1111 1111 1111 uuuu uuuu t2con pic18f6xk22 pic18f8xk22 -000 0000 - 000 0000 -uuu uuuu ssp1buf pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ssp1add pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu ssp1stat pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu ssp1con1 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu ssp1con2 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu adresh pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu adresl pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu adcon0 pic18f6xk22 pic18f8xk22 -000 0000 -000 0000 -uuu uuuu adcon1 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu adcon2 pic18f6xk22 pic18f8xk22 0- 00 0000 0-00 0000 u-uu uuuu table 5-2: initialization conditi ons for all registers (continued) register applicable devices power-on reset, brown-out reset mclr resets, wdt reset, reset instruction, stack resets, cm resets wake-up via wdt or interrupt legend: u = unchanged, x = unknown, - = unimplemented bit, read as 0 , q = value depends on condition. shaded cells indicate conditions do not apply for the designated device. note 1: when the wake-up is due to an interrupt, and the giel or gieh bit is set, the tosu, tosh and tosl are updated with the current value of the pc. the stkptr is modified to point to t he next location in the hardware stack. 2: when the wake-up is due to an interrupt and the giel or gieh bit is set, the pc is loaded with the interrupt vector (0008h or 0018h). 3: one or more bits in the intconx or pirx registers will be affected (to cause wak e-up). 4: see table 5-1 for reset value for specific condition. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 81 pic18f87k22 family eccp1as pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu eccp1del pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu ccpr1h pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccpr1l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccp1con pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu pir5 pic18f65k22 pic18f85k22 ---0 -000 ---0 -000 ---u -uuu pir5 pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 0000 0000 0000 0000 uuuu uuuu pie5 pic18f65k22 pic18f85k22 ---0 0000 ---0 0000 ---u uuuu ( 1 ) pie5 pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 0000 000 0000 0000 uuuu uuuu ( 1 ) ipr4 pic18f65k22 pic18f85k22 --11 1111 --11 1111 --uu uuuu ipr4 pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 1111 1111 1111 1111 uuuu uuuu pir4 pic18f65k22 pic18f85k22 --00 0000 --00 0000 --uu uuuu ( 1 ) pir4 pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 0000 0000 0000 0000 uuuu uuuu ( 1 ) pie4 pic18f65k22 pic18f85k22 --00 0000 --00 0000 --uu uuuu pie4 pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 0000 0000 0000 0000 uuuu uuuu cvrcon pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu cmstat pic18f6xk22 pic18f8xk22 xxx- ---- xxx- ---- uuu- ---- tmr3h pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu tmr3l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu t3con pic18f6xk22 pic18f8xk22 0000 0000 0000 0x00 uuuu uuuu t3gcon pic18f6xk22 pic18f8xk22 0000 0x00 0000 0000 uuuu uuuu spbrg1 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu rcreg1 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu txreg1 pic18f6xk22 pic18f8xk22 xxxx xxxx xxxx xxxx uuuu uuuu txsta1 pic18f6xk22 pic18f8xk22 0000 0010 0000 0010 uuuu uuuu rcsta1 pic18f6xk22 pic18f8xk22 0000 000x 0000 000x uuuu uuuu t1gcon pic18f6xk22 pic18f8xk22 0000 0x00 0000 0x00 uuuu -uuu ipr6 pic18f6xk22 pic18f8xk22 ---1 -111 ---1 -111 ---u -uuu hlvdcon pic18f6xk22 pic18f8xk22 0000 0101 0000 0101 uuuu uuuu pspcon pic18f6xk22 pic18f8xk22 0000 ---- 0000 ---- uuuu ---- pir6 pic18f6xk22 pic18f8xk22 ---0 -000 ---0 -000 ---u -uuu table 5-2: initialization conditions for all registers (continued) register applicable devices power-on reset, brown-out reset mclr resets, wdt reset, reset instruction, stack resets, cm resets wake-up via wdt or interrupt legend: u = unchanged, x = unknown, - = unimplemented bit, read as 0 , q = value depends on condition. shaded cells indicate conditions do not apply for the designated device. note 1: when the wake-up is due to an interrupt, and the giel or gieh bit is set, t he tosu, tosh and tosl are updated with the current value of the pc. the stkptr is modified to point to t he next location in the hardware stack. 2: when the wake-up is due to an interrupt and the giel or gieh bit is set, the pc is loaded with the interrupt vector (0008h or 0018h). 3: one or more bits in the intconx or pirx registers will be affected (to cause wak e-up). 4: see table 5-1 for reset value for specific condition. downloaded from: http:///
pic18f87k22 family ds39960d-page 82 ? 2009-2011 microchip technology inc. ipr3 pic18f6xk22 pic18f8xk22 1-11 1111 1-11 1111 u-uu uuuu pir3 pic18f6xk22 pic18f8xk22 0-00 0000 0-00 0000 u-uu uuuu pie3 pic18f6xk22 pic18f8xk22 0-00 0000 0-00 0000 u-uu uuuu ipr2 pic18f6xk22 pic18f8xk22 1-11 1111 1-11 1111 u-uu uuuu pir2 pic18f6xk22 pic18f8xk22 0-10 0000 0-10 0000 u-uu uuuu pie2 pic18f6xk22 pic18f8xk22 0-00 0000 0-00 0000 u-uu uuuu ipr1 pic18f6xk22 pic18f8xk22 1111 1111 1111 1111 uuuu uuuu pir1 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu pie1 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu pstr1con pic18f6xk22 pic18f8xk22 00-0 0001 00-0 0001 uu-u uuuu osctune pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu trisj pic18f6xk22 pic18f8xk22 1111 1111 1111 1111 uuuu uuuu trish pic18f6xk22 pic18f8xk22 1111 1111 1111 1111 uuuu uuuu trisg pic18f6xk22 pic18f8xk22 ---1 1111 ---1 1111 ---u uuuu trisf pic18f6xk22 pic18f8xk22 1111 111- 1111 111- ---u uuuu trise pic18f6xk22 pic18f8xk22 1111 1111 1111 1111 uuuu uuuu trisd pic18f6xk22 pic18f8xk22 1111 1111 1111 1111 uuuu uuuu trisc pic18f6xk22 pic18f8xk22 1111 1111 1111 1111 uuuu uuuu trisb pic18f6xk22 pic18f8xk22 1111 1111 1111 1111 uuuu uuuu trisa pic18f6xk22 pic18f8xk22 1111 1111 1111 1111 uuuu uuuu latj pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu lath pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu latg pic18f6xk22 pic18f8xk22 ---x xxxx ---u uuuu ---u uuuu latf pic18f6xk22 pic18f8xk22 xxxx xxx- uuuu uuu- uuuu uuu- late pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu latd pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu latc pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu latb pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu lata pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu portj pic18f6xk22 pic18f8xk22 xxxx xxxx xxxx xxxx uuuu uuuu porth pic18f6xk22 pic18f8xk22 xxxx xxxx xxxx xxxx uuuu uuuu portg pic18f6xk22 pic18f8xk22 --xx xxxx --xx xxxx --uu uuuu portf pic18f6xk22 pic18f8xk22 xxxx xxx- xxxx xxx- uuuu uuu- porte pic18f6xk22 pic18f8xk22 xxxx xxxx xxxx xxxx uuuu uuuu portd pic18f6xk22 pic18f8xk22 xxxx xxxx xxxx xxxx uuuu uuuu table 5-2: initialization conditi ons for all registers (continued) register applicable devices power-on reset, brown-out reset mclr resets, wdt reset, reset instruction, stack resets, cm resets wake-up via wdt or interrupt legend: u = unchanged, x = unknown, - = unimplemented bit, read as 0 , q = value depends on condition. shaded cells indicate conditions do not apply for the designated device. note 1: when the wake-up is due to an interrupt, and the giel or gieh bit is set, the tosu, tosh and tosl are updated with the current value of the pc. the stkptr is modified to point to t he next location in the hardware stack. 2: when the wake-up is due to an interrupt and the giel or gieh bit is set, the pc is loaded with the interrupt vector (0008h or 0018h). 3: one or more bits in the intconx or pirx registers will be affected (to cause wak e-up). 4: see table 5-1 for reset value for specific condition. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 83 pic18f87k22 family portc pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu portb pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu porta pic18f6xk22 pic18f8xk22 xx0x 0000 uu0u 0000 uuuu uuuu eecon1 pic18f6xk22 pic18f8xk22 xx-0 x000 uu-0 u000 uu-u uuuu eecon2 pic18f6xk22 pic18f8xk22 ---- ---- ---- ---- ---- ---- tmr5h pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu tmr5l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu t5con pic18f6xk22 pic18f8xk22 0000 0000 uuuu uuuu uuuu uuuu t5gcon pic18f6xk22 pic18f8xk22 0000 0x00 uuuu uuuu uuuu uuuu ccpr4h pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccpr4l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccp4con pic18f6xk22 pic18f8xk22 --00 0000 --00 0000 --uu uuuu ccpr5h pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccpr5l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccp5con pic18f6xk22 pic18f8xk22 --00 0000 --00 0000 --uu uuuu ccpr6h pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccpr6l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccp6con pic18f6xk22 pic18f8xk22 --00 0000 --00 0000 --uu uuuu ccpr7h pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccpr7l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccp7con pic18f6xk22 pic18f8xk22 --00 0000 --00 0000 --uu uuuu tmr4 pic18f6xk22 pic18f8xk22 xxxx xxxx xxxx xxxx uuuu uuuu pr4 pic18f6xk22 pic18f8xk22 1111 1111 1111 1111 1111 1111 t4con pic18f6xk22 pic18f8xk22 -111 1111 -111 1111 -uuu uuuu ssp2buf pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ssp2add pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu ssp2stat pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu ssp2con1 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu ssp2con2 pic18f6xk22 pic18f8xk22 0100 0000 0000 0000 uuuu uuuu baudcon1 pic18f6xk22 pic18f8xk22 0100 0-00 0100 0-00 uuuu u-uu osccon2 pic18f6xk22 pic18f8xk22 -0-- 0-x0 -0-- 0-u0 -u-- u-uu eeadrh pic18f6xk22 pic18f8xk22 ---- --00 ---- --00 ---- --uu eeadr pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu eedata pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu pie6 pic18f6xk22 pic18f8xk22 ---0 -000 ---0 -000 ---u -uuu table 5-2: initialization conditions for all registers (continued) register applicable devices power-on reset, brown-out reset mclr resets, wdt reset, reset instruction, stack resets, cm resets wake-up via wdt or interrupt legend: u = unchanged, x = unknown, - = unimplemented bit, read as 0 , q = value depends on condition. shaded cells indicate conditions do not apply for the designated device. note 1: when the wake-up is due to an interrupt, and the giel or gieh bit is set, t he tosu, tosh and tosl are updated with the current value of the pc. the stkptr is modified to point to t he next location in the hardware stack. 2: when the wake-up is due to an interrupt and the giel or gieh bit is set, the pc is loaded with the interrupt vector (0008h or 0018h). 3: one or more bits in the intconx or pirx registers will be affected (to cause wak e-up). 4: see table 5-1 for reset value for specific condition. downloaded from: http:///
pic18f87k22 family ds39960d-page 84 ? 2009-2011 microchip technology inc. rtccfg pic18f6xk22 pic18f8xk22 0-00 0000 u-uu uuuu u-uu uuuu rtccal pic18f6xk22 pic18f8xk22 0000 0000 uuuu uuuu uuuu uuuu rtcvalh pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu rtcvall pic18f6xk22 pic18f8xk22 0000 0000 uuuu uuuu uuuu uuuu alrmcfg pic18f6xk22 pic18f8xk22 0000 0000 uuuu uuuu uuuu uuuu alrmrpt pic18f6xk22 pic18f8xk22 0000 0000 uuuu uuuu uuuu uuuu alrmvalh pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu alrmvall pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ctmuconh pic18f6xk22 pic18f8xk22 0-00 0000 0-00 0000 u-uu uuuu ctmuconl pic18f6xk22 pic18f8xk22 0000 00xx 0000 00xx uuuu uuuu ctmuiconh pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu cm1con pic18f6xk22 pic18f8xk22 0001 1111 0001 1111 uuuu uuuu padcfg1 pic18f6xk22 pic18f8xk22 00-- -00- uu-- -uu- uu-- -uu- padcfg1 pic18f6xk22 pic18f8xk22 000- -00- uuu- -uu- uuu- -uu- eccp2as pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu eccp2del pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu ccpr2h pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccpr2l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccp2con pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu eccp3as pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu eccp3del pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu ccpr3h pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccpr3l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccp3con pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu ccpr8h pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccpr8l pic18f6xk22 pic18f8xk22 xxxx xxxx uuuu uuuu uuuu uuuu ccp8con pic18f6xk22 pic18f8xk22 --00 0000 --00 0000 --uu uuuu ccpr9h pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 xxxx xxxx uuuu uuuu uuuu uuuu ccpr9l pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 xxxx xxxx uuuu uuuu uuuu uuuu ccp9con pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 --00 0000 --00 0000 --uu uuuu ccpr10h pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 xxxx xxxx uuuu uuuu uuuu uuuu ccpr10l pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 xxxx xxxx uuuu uuuu uuuu uuuu table 5-2: initialization conditi ons for all registers (continued) register applicable devices power-on reset, brown-out reset mclr resets, wdt reset, reset instruction, stack resets, cm resets wake-up via wdt or interrupt legend: u = unchanged, x = unknown, - = unimplemented bit, read as 0 , q = value depends on condition. shaded cells indicate conditions do not apply for the designated device. note 1: when the wake-up is due to an interrupt, and the giel or gieh bit is set, the tosu, tosh and tosl are updated with the current value of the pc. the stkptr is modified to point to t he next location in the hardware stack. 2: when the wake-up is due to an interrupt and the giel or gieh bit is set, the pc is loaded with the interrupt vector (0008h or 0018h). 3: one or more bits in the intconx or pirx registers will be affected (to cause wak e-up). 4: see table 5-1 for reset value for specific condition. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 85 pic18f87k22 family ccp10con pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 --00 0000 --00 0000 --uu uuuu tmr7h pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 xxxx xxxx uuuu uuuu uuuu uuuu tmr7l pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 xxxx xxxx uuuu uuuu uuuu uuuu t7con pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 0000 0000 uuuu uuuu uuuu uuuu t7gcon pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 0000 0x00 0000 0x00 uuuu uuuu tmr6 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu pr6 pic18f6xk22 pic18f8xk22 1111 1111 1111 1111 uuuu uuuu t6con pic18f6xk22 pic18f8xk22 -000 0000 -000 0000 -uuu uuuu tmr8 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu pr8 pic18f6xk22 pic18f8xk22 1111 1111 1111 1111 uuuu uuuu t8con pic18f6xk22 pic18f8xk22 -000 0000 -000 0000 -uuu uuuu tmr10 pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 0000 0000 0000 0000 uuuu uuuu pr10 pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 1111 1111 1111 1111 uuuu uuuu t10con pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 -000 0000 -000 0000 -uuu uuuu tmr12 pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 0000 0000 0000 0000 uuuu uuuu pr12 pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 1111 1111 1111 1111 uuuu uuuu t12con pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 -000 0000 -000 0000 -uuu uuuu cm2con pic18f6xk22 pic18f8xk22 0001 1111 0001 1111 uuuu uuuu cm3con pic18f6xk22 pic18f8xk22 0001 1111 0001 1111 uuuu uuuu ccptmrs0 pic18f6xk22 pic18f8xk22 0000 0000 uuuu uuuu uuuu uuuu ccptmrs1 pic18f6xk22 pic18f8xk22 00-0 -000 uu-u -uuu uu-u -uuu ccptmrs2 pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 ---0 -000 ---u -uuu ---u -uuu ccptmrs2 pic18f65k22 pic18f85k22 ---- --00 ---- --uu ---- --uu refocon pic18f6xk22 pic18f8xk22 0-00 0000 u-uu uuuu u-uu uuuu odcon1 pic18f6xk22 pic18f8xk22 000- ---0 uuu- ---u uuu- ---u table 5-2: initialization conditions for all registers (continued) register applicable devices power-on reset, brown-out reset mclr resets, wdt reset, reset instruction, stack resets, cm resets wake-up via wdt or interrupt legend: u = unchanged, x = unknown, - = unimplemented bit, read as 0 , q = value depends on condition. shaded cells indicate conditions do not apply for the designated device. note 1: when the wake-up is due to an interrupt, and the giel or gieh bit is set, t he tosu, tosh and tosl are updated with the current value of the pc. the stkptr is modified to point to t he next location in the hardware stack. 2: when the wake-up is due to an interrupt and the giel or gieh bit is set, the pc is loaded with the interrupt vector (0008h or 0018h). 3: one or more bits in the intconx or pirx registers will be affected (to cause wak e-up). 4: see table 5-1 for reset value for specific condition. downloaded from: http:///
pic18f87k22 family ds39960d-page 86 ? 2009-2011 microchip technology inc. odcon2 pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 0000 0000 uuuu uuuu uuuu uuuu odcon2 pic18f65k22 pic18f85k22 --00 0000 --uu uuuu --uu uuuu odcon3 pic18f6xk22 pic18f8xk22 00-- ---0 uu-- ---u uu-- ---u memcon pic18f6xk22 pic18f8xk22 0-00 --00 0-00 --00 u-uu --uu ancon0 pic18f6xk22 pic18f8xk22 1111 1111 uuuu uuuu uuuu uuuu ancon1 pic18f6xk22 pic18f8xk22 1111 1111 uuuu uuuu uuuu uuuu ancon2 pic18f6xk22 pic18f8xk22 1111 1111 uuuu uuuu uuuu uuuu rcsta2 pic18f6xk22 pic18f8xk22 0000 000x 0000 000x uuuu uuuu txsta2 pic18f6xk22 pic18f8xk22 0000 0010 0000 0010 uuuu uuuu baudcon2 pic18f6xk22 pic18f8xk22 0100 0-00 0100 0-00 uuuu u-uu spbrgh2 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu spbrg2 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu rcreg2 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu txreg2 pic18f6xk22 pic18f8xk22 xxxx xxxx xxxx xxxx uuuu uuuu pstr2con pic18f6xk22 pic18f8xk22 00-0 0001 00-0 0001 uu-u uuuu pstr3con pic18f6xk22 pic18f8xk22 00-0 0001 00-0 0001 uu-u uuuu pmd0 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu pmd1 pic18f6xk22 pic18f8xk22 0000 0000 0000 0000 uuuu uuuu pmd2 pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 0000 0000 0000 0000 uuuu uuuu pmd2 pic18f65k22 pic18f85k22 -0-0 0000 -0-0 0000 -u-u uuuu pmd3 pic18f66k22 pic18f67k22 pic18f86k22 pic18f87k22 0000 0000 0000 0000 uuuu uuuu pmd3 pic18f65k22 pic18f85k22 --00 000- --00 000- --uu uuu- table 5-2: initialization conditi ons for all registers (continued) register applicable devices power-on reset, brown-out reset mclr resets, wdt reset, reset instruction, stack resets, cm resets wake-up via wdt or interrupt legend: u = unchanged, x = unknown, - = unimplemented bit, read as 0 , q = value depends on condition. shaded cells indicate conditions do not apply for the designated device. note 1: when the wake-up is due to an interrupt, and the giel or gieh bit is set, the tosu, tosh and tosl are updated with the current value of the pc. the stkptr is modified to point to t he next location in the hardware stack. 2: when the wake-up is due to an interrupt and the giel or gieh bit is set, the pc is loaded with the interrupt vector (0008h or 0018h). 3: one or more bits in the intconx or pirx registers will be affected (to cause wak e-up). 4: see table 5-1 for reset value for specific condition. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 87 pic18f87k22 family 6.0 memory organization pic18f87k22 family devices have these types of memory: program memory data ram data eeprom as harvard architecture devices, the data and program memories use separate busses. this enables concurrent access of the two memory spaces. the data eeprom, for practical purposes, can be regarded as a peripheral device because it is addressed and accessed through a set of control registers. additional detailed information on the operation of the flash program memory is provided in section 7.0 flash program memory . the data eeprom is discussed separately in section 9.0 data eeprom memory . figure 6-1: memory maps for pic18f87k22 family devices note: sizes of memory areas are not to scale. sizes of program memory areas are enhanced to show detail. unimplemented read as 0 unimplemented read as 0 000000h 1fffffh 01ffffh 00ffffh pc<20:0> stack level 1 ? stack level 31 ?? call, callw, rcall, return, retfie, retlw, 21 user memory space on-chip memory on-chip memory addulnk, subulnk pic18fx6k22 pic18fx7k22 unimplemented read as 0 on-chip memory pic18fx5k22 007fffh downloaded from: http:///
pic18f87k22 family ds39960d-page 88 ? 2009-2011 microchip technology inc. 6.1 program memory organization pic18 microcontrollers implement a 21-bit program counter that is capable of addressing a 2-mbyte program memory space. accessing a location between the upper boundary of the physically implemented memory and the 2-mbyte address will return all 0 s (a nop instruction). the entire pic18f87k22 family offers a range of on-chip flash program memory sizes, from 32 kbytes (up to 16,384 single-word instructions) to 128 kbytes (65,536 single-word instructions). pic18f65k22 and pic18f85k22 C 32 kbytes of flash memory, storing up to 16,384 single-word instructions pic18f66k22 and pic18f86k22 C 64 kbytes of flash memory, storing up to 32,768 single-word instructions pic18f67k22 and pic18f87k22 C 128 kbytes of flash memory, storing up to 65,536 single-word instructions the program memory maps for individual family members are shown in figure 6-1 . 6.1.1 hard memory vectors all pic18 devices have a total of three hard-coded return vectors in their program memory space. the reset vector address is the default value to which the program counter returns on all device resets; it is located at 0000h. pic18 devices also have two interrupt vector addresses for handling high-priority and low-priority interrupts. the high-priority interrupt vector is located at 0008h and the low-priority interrupt vector is at 0018h. the locations of these vectors are shown, in relation to the program memory map, in figure 6-2 . figure 6-2: hard vector for pic18f87k22 family devices reset vector low-priority interrupt vector 0000h0018h on-chip program memory high-priority interrupt vector 0008h 1fffffh read 0 legend: (top of memory) represents upper boundary of on-chip program memory space (see figure 6-1 for device-specific values). shaded area represents unimplemented memory. areas are not shown to scale. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 89 pic18f87k22 family 6.1.2 program counter the program counter (pc) specifies the address of the instruction to fetch for execution. the pc is 21 bits wide and contained in three separate 8-bit registers. the low byte, known as the pcl register, is both readable and writable. the high byte, or pch register, contains the pc<15:8> bits and is not directly readable or writable. updates to the pch register are performed through the pclath register. the upper byte is called pcu. this register contains the pc<20:16> bits; it is also not directly readable or writable. updates to the pcu register are performed through the pclatu register. the contents of pclath and pclatu are transferred to the program counter by any operation that writes pcl. similarly, the upper two bytes of the program counter are transferred to pclath and pclatu by an operation that reads pcl. this is useful for computed offsets to the pc (see section 6.1.5.1 computed goto ). the pc addresses bytes in the program memory. to prevent the pc from becoming misaligned with word instructions, the least significant bit of pcl is fixed to a value of 0 . the pc increments by two to address sequential instructions in the program memory. the call , rcall , goto and program branch instructions write to the program counter directly. for these instructions, the contents of pclath and pclatu are not transferred to the program counter. 6.1.3 return address stack the return address stack enables execution of any combination of up to 31 program calls and interrupts. the pc is pushed onto the stack when a call or rcall instruction is executed or an interrupt is acknowledged. the pc value is pulled off the stack on a return , retlw or a retfie instruction. the value also is pulled off the stack on addulnk and subulnk instructions, if the extended instruction set is enabled. pclatu and pclath are not affected by any of the return or call instructions. the stack operates as a 31-word by 21-bit ram and a 5-bit stack pointer, stkptr. the stack space is not part of either program or data space. the stack pointer is readable and writable and the address on the top of the stack is readable and writable through the top-of-stack special function registers. data can also be pushed to, or popped from, the stack using these registers. a call type instruction causes a push onto the stack. the stack pointer is first incremented and the location pointed to by the stack pointer is written with the contents of the pc (already pointing to the instruction following the call ). a return type instruction causes a pop from the stack. the contents of the location pointed to by the stkptr are transferred to the pc and then the stack pointer is decremented. the stack pointer is initialized to 00000 after all resets. there is no ram associated with the location corresponding to a stack pointer value of 00000 ; this is only a reset value. status bits indicate if the stack is full, has overflowed or has underflowed. 6.1.3.1 top-of-stack access only the top of the return address stack (tos) is readable and writable. a set of three registers, tosu:tosh:tosl, holds the contents of the stack location pointed to by the stkptr register ( figure 6-3 ). this allows users to implement a software stack, if necessary. after a call , rcall or interrupt (or addulnk and subulnk instructions, if the extended instruction set is enabled), the software can read the pushed value by reading the tosu:tosh:tosl regis- ters. these values can be placed on a user-defined software stack. at return time, the software can return these values to tosu:tosh:tosl and do a return. while accessing the stack, users must disable the global interrupt enable bits to prevent inadvertent stack corruption. figure 6-3: return address stack and associated registers 00011 001a34h 11111 11110 11101 00010 00001 00000 00010 return address stack <20:0> top-of-stack 000d58h tosl tosh tosu 34h 1ah 00h stkptr<4:0> top-of-stack registers stack pointer downloaded from: http:///
pic18f87k22 family ds39960d-page 90 ? 2009-2011 microchip technology inc. 6.1.3.2 return stack pointer (stkptr) the stkptr register ( register 6-1 ) contains the stack pointer value, the stkful (stack full) status bit and the stkunf (stack underflow) status bits. the value of the stack pointer can be 0 through 31. the stack pointer increments before values are pushed onto the stack and decrements after values are popped off the stack. on reset, the stack pointer value will be zero. the user may read and write the stack pointer value. this feature can be used by a real-time operating system (rtos) for return stack maintenance. after the pc is pushed onto the stack 31 times (without popping any values off the stack), the stkful bit is set. the stkful bit is cleared by software or by a por. what happens when the stack becomes full depends on the state of the stvren (stack overflow reset enable) configuration bit. (for a description of the device configuration bits, see section 28.1 configu- ration bits .) if stvren is set (default), the 31st push will push the (pc + 2) value onto the stack, set the stkful bit and reset the device. the stkful bit will remain set and the stack pointer will be set to zero. if stvren is cleared, the stkful bit will be set on the 31st push and the stack pointer will increment to 31. any additional pushes will not overwrite the 31st push and the stkptr will remain at 31. when the stack has been popped enough times to unload the stack, the next pop will return a value of zero to the pc and set the stkunf bit while the stack pointer remains at zero. the stkunf bit will remain set until cleared by software or until a por occurs. 6.1.3.3 push and pop instructions since the top-of-stack (tos) is readable and writable, the ability to push values onto the stack and pull values off of the stack, without disturbing normal program exe- cution, is a desirable feature. the pic18 instruction set includes two instructions, push and pop , that permit the tos to be manipulated under software control. tosu, tosh and tosl can be modified to place data or a return address on the stack. the push instruction places the current pc value onto the stack. this increments the stack pointer and loads the current pc value onto the stack. the pop instruction discards the current tos by decrementing the stack pointer. the previous value pushed onto the stack then becomes the tos value. note: returning a value of zero to the pc on an underflow has the effect of vectoring the program to the reset vector, where the stack conditions can be verified and appropriate actions can be taken. this is not the same as a reset as the contents of the sfrs are not affected. register 6-1: stkptr: stack pointer register r/c-0 r/c-0 u-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 stkful ( 1 ) stkunf ( 1 ) sp4 sp3 sp2 sp1 sp0 bit 7 bit 0 legend: c = clearable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 stkful: stack full flag bit ( 1 ) 1 = stack has become full or overflowed 0 = stack has not become full or overflowed bit 6 stkunf: stack underflow flag bit ( 1 ) 1 = stack underflow has occurred 0 = stack underflow did not occur bit 5 unimplemented: read as 0 bit 4-0 sp<4:0>: stack pointer location bits note 1: bit 7 and bit 6 are cleared by user software or by a por. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 91 pic18f87k22 family 6.1.3.4 stack full and underflow resets device resets on stack overflow and stack underflow conditions are enabled by setting the stvren bit (config4l<0>). when stvren is set, a full or under- flow condition will set the appropriate stkful or stkunf bit and then cause a device reset. when stvren is cleared, a full or underflow condition will set the appropriate stkful or stkunf bit, but not cause a device reset. the stkful or stkunf bits are cleared by the user software or a power-on reset. 6.1.4 fast register stack a fast register stack is provided for the status, wreg and bsr registers to provide a fast return option for interrupts. this stack is only one level deep and is neither readable nor writable. it is loaded with the current value of the corresponding register when the processor vectors for an interrupt. all interrupt sources will push values into the stack registers. the values in the registers are then loaded back into the working registers if the retfie , fast instruction is used to return from the interrupt. if both low and high-priority interrupts are enabled, the stack registers cannot be used reliably to return from low-priority interrupts. if a high-priority interrupt occurs while servicing a low-priority interrupt, the stack register values stored by the low-priority interrupt will be overwritten. in these cases, users must save the key registers in software during a low-priority interrupt. if interrupt priority is not used, all interrupts may use the fast register stack for returns from interrupt. if no interrupts are used, the fast register stack can be used to restore the status, wreg and bsr registers at the end of a subroutine call. to use the fast register stack for a subroutine call, a call label , fast instruction must be executed to save the status, wreg and bsr registers to the fast register stack. a return , fast instruction is then executed to restore these registers from the fast register stack. example 6-1 shows a source code example that uses the fast register stack during a subroutine call and return. example 6-1: fast register stack code example 6.1.5 look-up tables in program memory there may be programming situations that require the creation of data structures, or look-up tables, in program memory. for pic18 devices, look-up tables can be implemented in two ways: computed goto table reads 6.1.5.1 computed goto a computed goto is accomplished by adding an offset to the program counter. an example is shown in example 6-2 . a look-up table can be formed with an addwf pcl instruction and a group of retlw nn instructions. the w register is loaded with an offset into the table before executing a call to that table. the first instruction of the called routine is the addwf pcl instruction. the next instruction executed will be one of the retlw nn instructions that returns the value, nn , to the calling function. the offset value (in wreg) specifies the number of bytes that the program counter should advance and should be multiples of two (lsb = 0 ). in this method, only one data byte may be stored in each instruction location and room on the return address stack is required. example 6-2: computed goto using an offset value 6.1.5.2 table reads a better method of storing data in program memory allows two bytes of data to be stored in each instruction location. look-up table data may be stored, two bytes per program word, while programming. the table pointer (tblptr) specifies the byte address and the table latch (tablat) contains the data that is read from the program memory. data is transferred from program memory, one byte at a time. the table read operation is discussed further in section 7.1 table reads and table writes . call sub1, fast ;status, wreg, bsr ;saved in fast register;stack ?? sub1 ?? return fast ;restore values saved ;in fast register stack movf offset, w call table org nn00h table addwf pcl retlw nnh retlw nnh retlw nnh . . . downloaded from: http:///
pic18f87k22 family ds39960d-page 92 ? 2009-2011 microchip technology inc. 6.2 pic18 instruction cycle 6.2.1 clocking scheme the microcontroller clock input, whether from an internal or external source, is internally divided by four to generate four non-overlapping, quadrature clocks (q1, q2, q3 and q4). internally, the program counter is incremented on every q1, with the instruction fetched from the program memory and latched into the instruction register (ir) during q4. the instruction is decoded and executed during the following q1 through q4. the clocks and instruction execution flow are shown in figure 6-4 . 6.2.2 instruction flow/pipelining an instruction cycle consists of four q cycles, q1 through q4. the instruction fetch and execute are pipe- lined in such a manner that a fetch takes one instruction cycle, while the decode and execute take another instruction cycle. however, due to the pipelining, each instruction effectively executes in one cycle. if an instruction (such as goto ) causes the program counter to change, two cycles are required to complete the instruction. (see example 6-3 .) a fetch cycle begins with the program counter (pc) incrementing in q1. in the execution cycle, the fetched instruction is latched into the instruction register (ir) in cycle q1. this instruction is then decoded and executed during the q2, q3 and q4 cycles. data memory is read during q2 (operand read) and written during q4 (destination write). figure 6-4: clock/ instruction cycle example 6-3: instruction pipeline flow q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 osc1 q1q2 q3 q4 pc osc2/clko (rc mode) pc pc + 2 pc + 4 fetch inst (pc) execute inst (pc C 2) fetch inst (pc + 2) execute inst (pc) fetch inst (pc + 4) execute inst (pc + 2) internal phase clock all instructions are single cycle, except for any program branches. these take two cycles sin ce the fetch instruction is flushed from the pipeline while the new instruction is being fetched and then executed. t cy 0t cy 1t cy 2t cy 3t cy 4t cy 5 1. movlw 55h fetch 1 execute 1 2. movwf portb fetch 2 execute 2 3. bra sub_1 fetch 3 execute 3 4. bsf porta, bit3 (forced nop) fetch 4 flush ( nop ) 5. instruction @ address sub_1 fetch sub_1 execute sub_1 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 93 pic18f87k22 family 6.2.3 instructions in program memory the program memory is addressed in bytes. instruc- tions are stored as two or four bytes in program memory. the least significant byte of an instruction word is always stored in a program memory location with an even address (lsb = 0 ). to maintain alignment with instruction boundaries, the pc increments in steps of two and the lsb will always read 0 (see section 6.1.2 program counter ). figure 6-5 shows an example of how instruction words are stored in the program memory. the call and goto instructions have the absolute program memory address embedded into the instruc- tion. since instructions are always stored on word boundaries, the data contained in the instruction is a word address. the word address is written to pc<20:1> which accesses the desired byte address in program memory. instruction #2 in figure 6-5 shows how the instruction, goto 0006h , is encoded in the program memory. program branch instructions, which encode a relative address offset, operate in the same manner. the offset value stored in a branch instruction represents the number of single-word instructions that the pc will be offset by. for more details on the instruction set, see section 29.0 instruction set summary . figure 6-5: instructions in program memory 6.2.4 two-word instructions the standard pic18 instruction set has four, two-word instructions: call , movff , goto and lsfr . in all cases, the second word of the instructions always has 1111 as its four most significant bits. the other 12 bits are literal data, usually a data memory address. the use of 1111 in the 4 msbs of an instruction specifies a special form of nop . if the instruction is executed in proper sequence, immediately after the first word, the data in the second word is accessed and used by the instruction sequence. if the first word is skipped, for some reason, and the second word is executed by itself, a nop is executed instead. this is necessary for cases when the two-word instruction is preceded by a conditional instruction that changes the pc. example 6-4 shows how this works. example 6-4: two- word instructions word address lsb = 1 lsb = 0 ? program memory byte locations ? ? 000000h000002h 000004h 000006h instruction 1: movlw 055h 0fh 55h 000008h instruction 2: goto 0006h efh 03h 00000ah f0h 00h 00000ch instruction 3: movff 123h, 456h c1h 23h 00000eh f4h 56h 000010h 000012h000014h note: for information on two-word instructions in the extended instruction set, see section 6.5 program memory and the extended instruction set . case 1: object code source code 0110 0110 0000 0000 tstfsz reg1 ; is ram location 0? 1100 0001 0010 0011 movff reg1, reg2 ; no, skip this word 1111 0100 0101 0110 ; execute this word as a nop 0010 0100 0000 0000 addwf reg3 ; continue code case 2: object code source code 0110 0110 0000 0000 tstfsz reg1 ; is ram location 0? 1100 0001 0010 0011 movff reg1, reg2 ; yes, execute this word 1111 0100 0101 0110 ; 2nd word of instruction 0010 0100 0000 0000 addwf reg3 ; continue code downloaded from: http:///
pic18f87k22 family ds39960d-page 94 ? 2009-2011 microchip technology inc. 6.3 data memory organization the data memory in pic18 devices is implemented as static ram. each register in the data memory has a 12-bit address, allowing up to 4,096 bytes of data memory. the memory space is divided into as many as 16 banks that contain 256 bytes each. pic18fx6k22 and pic18fx7k22 devices implement all 16 complete banks, for a total of 4 kbytes. pic18fx5k22 devices implement only the first eight complete banks, for a total of 2 kbytes. figure 6-6 and figure 6-7 show the data memory organization for the devices. the data memory contains special function registers (sfrs) and general purpose registers (gprs). the sfrs are used for control and status of the controller and peripheral functions, while gprs are used for data storage and scratchpad operations in the users application. any read of an unimplemented location will read as 0 s. the instruction set and architecture allow operations across all banks. the entire data memory may be accessed by direct, indirect or indexed addressing modes. addressing modes are discussed later in this section. to ensure that commonly used registers (select sfrs and select gprs) can be accessed in a single cycle, pic18 devices implement an access bank. this is a 256-byte memory space that provides fast access to select sfrs and the lower portion of gpr bank 0 with- out using the bank select register. for details on the access ram, see section 6.3.2 access bank . 6.3.1 bank select register large areas of data memory require an efficient addressing scheme to make it possible for rapid access to any address. ideally, this means that an entire address does not need to be provided for each read or write operation. for pic18 devices, this is accom- plished with a ram banking scheme. this divides the memory space into 16 contiguous banks of 256 bytes. depending on the instruction, each location can be addressed directly by its full 12-bit address, or an 8-bit, low-order address and a 4-bit bank pointer. most instructions in the pic18 instruction set make use of the bank pointer, known as the bank select register (bsr). this sfr holds the four most significant bits of a locations address. the instruction itself includes the eight least significant bits. only the four lower bits of the bsr are implemented (bsr<3:0>). the upper four bits are unused, always read as 0 and cannot be written to. the bsr can be loaded directly by using the movlb instruction. the value of the bsr indicates the bank in data memory. the eight bits in the instruction show the loca- tion in the bank and can be thought of as an offset from the banks lower boundary. the relationship between the bsrs value and the bank division in data memory is shown in figure 6-7 . since up to 16 registers may share the same low-order address, the user must always be careful to ensure that the proper bank is selected before performing a data read or write. for example, writing what should be program data to an eight-bit address of f9h, while the bsr is 0fh, will end up resetting the program counter. while any bank can be selected, only those banks that are actually implemented can be read or written to. writes to unimplemented banks are ignored, while reads from unimplemented banks will return 0 s. even so, the status register will still be affected as if the operation was successful. the data memory map in figure 6-6 indicates which banks are implemented. in the core pic18 instruction set, only the movff instruction fully specifies the 12-bit address of the source and target registers. when this instruction executes, it ignores the bsr completely. all other instructions include only the low-order address as an operand and must use either the bsr or the access bank to locate their target registers. note: the operation of some aspects of data memory are changed when the pic18 extended instruction set is enabled. see section 6.6 data memory and the extended instruction set for more information. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 95 pic18f87k22 family figure 6-6: data memory map for pi c18fx5k22 and pic18fx7k22 devices 00h5fh 60h ffh access bank when a = 0 : the bsr is ignored and the access bank is used. the first 96 bytes are general purpose ram (from bank 0). the second 160 bytes are special function registers (from bank 15). when a = 1 : the bsr specifies the bank used by the instruction. access ram high access ram low (sfrs) bank 0 bank 1 bank 14 bank 15 data memory map bsr<3:0> = 0000 = 0001 = 1111 060h 05fh f60h fffh f5fh f00h effh 1ffh 100h 0ffh 000h access ram ffh 00h ffh 00h ffh 00h gpr gpr sfr bank 2 = 0010 2ffh 200h bank 3 ffh 00h gpr ffh = 0011 gpr (1,2) gpr gpr gpr gpr gpr 4ffh 400h 5ffh 500h 3ffh 300h ffh 00h ffh 00h ffh 00h ffh 00h ffh 00h 00h = 0110 = 0111 = 0101 = 0100 bank 4 bank 5 bank 6 bank 7 bank 8 = 1110 6ffh 600h 7ffh 700h 800h bank 9 bank 10 bank 11 bank 12 bank 13 8ffh 900h 9ffha00h affhb00h bffh c00h cffh d00h dffh e00h ffh 00h ffh 00h ffh 00h ffh 00h ffh 00h ffh 00h gpr (2) gpr (2) gpr (2) gpr (2) gpr (2) gpr (2) gpr (2) note 1: addresses, f16h through f5fh, are also used by sfrs, but are not part of the access ram. users must always use the complete address, or load the proper bsr value, to access these registers. 2: these addresses are unused for devices with 32 kbyt es of program memory (pic18fx5k22). for those devices, read these addresses at 00h. = 1000 = 1001 = 1010 = 1011 = 1100 = 1101 downloaded from: http:///
pic18f87k22 family ds39960d-page 96 ? 2009-2011 microchip technology inc. figure 6-7: use of the bank select register (direct addressing) 6.3.2 access bank while the use of the bsr, with an embedded 8-bit address, allows users to address the entire range of data memory, it also means that the user must ensure that the correct bank is selected. if not, data may be read from, or written to, the wrong location. this can be disastrous if a gpr is the intended target of an operation, but an sfr is written to instead. verifying and/or changing the bsr for each read or write to data memory can become very inefficient. to streamline access for the most commonly used data memory locations, the data memory is configured with an access bank, which allows users to access a mapped block of memory without specifying a bsr. the access bank consists of the first 96 bytes of memory (00h-5fh) in bank 0 and the last 160 bytes of memory (60h-ffh) in bank 15. the lower half is known as the access ram and is composed of gprs. the upper half is where the devices sfrs are mapped. these two areas are mapped contiguously in the access bank and can be addressed in a linear fashion by an eight-bit address ( figure 6-6 ). the access bank is used by core pic18 instructions that include the access ram bit (the a parameter in the instruction). when a is equal to 1 , the instruction uses the bsr and the 8-bit address included in the opcode for the data memory address. when a is 0 , however, the instruction is forced to use the access bank address map. in that case, the current value of the bsr is ignored entirely. using this forced addressing allows the instruction to operate on a data address in a single cycle without updating the bsr first. for 8-bit addresses of 60h and above, this means that users can evaluate and operate on sfrs more efficiently. the access ram below 60h is a good place for data values that the user might need to access rapidly, such as immediate computational results or common program variables. access ram also allows for faster and more code efficient context saving and switching of variables. the mapping of the access bank is slightly different when the extended instruction set is enabled (xinst configuration bit = 1 ). this is discussed in more detail in section 6.6.3 mapping the access bank in indexed literal offset mode . 6.3.3 general purpose register file pic18 devices may have banked memory in the gpr area. this is data ram which is available for use by all instructions. gprs start at the bottom of bank 0 (address 000h) and grow upwards towards the bottom of the sfr area. gprs are not initialized by a power-on reset and are unchanged on all other resets. note 1: the access ram bit of the instruction can be used to force an override of the selected bank (bsr<3:0>) to the registers of the access bank. 2: the movff instruction embeds the entire 12-bit address in the instruction. data memory bank select (2) 7 0 from opcode (2) 0000 000h100h 200h 300h f00h e00h fffh bank 0 bank 1 bank 2 bank 14 bank 15 00h ffh 00h ffh 00h ffh 00h ffh 00h ffh 00h ffh bank 3 through bank 13 0010 11111111 7 0 bsr (1) 11111111 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 97 pic18f87k22 family 6.3.4 special function registers the special function registers (sfrs) are registers used by the cpu and peripheral modules for controlling the desired operation of the device. these registers are implemented as static ram. sfrs start at the top of data memory (fffh) and extend downward to occupy all of bank 15 (f00h to fffh) and the top part of bank 14 (ef4h to effh). a list of these registers is given in tab l e 6 - 1 and table 6-2 . the sfrs can be classified into two sets: those associated with the core device functionality (alu, resets and interrupts) and those related to the peripheral functions. the reset and interrupt registers are described in their respective chapters, while the alus status register is described later in this section. registers related to the operation of the peripheral features are described in t he chapter for that peripheral. the sfrs are typically distributed among the peripherals whose functions they control. unused sfr locations are unimplemented and read as 0 s. table 6-1: special function register map for pic18f87k22 family addr. name addr. name addr. name addr. name addr. name addr. name ( 4 ) fffh tosu fdfh indf2 ( 1 ) fbfh eccp1as f9fh ipr1 f7fh eecon1 f5fh rtccfg ffeh tosh fdeh postinc2 ( 1 ) fbeh eccp1del f9eh pir1 f7eh eecon2 f5eh rtccal ffdh tosl fddh postdec2 ( 1 ) fbdh ccpr1h f9dh pie1 f7dh tmr5h f5dh rtcvalh ffch stkptr fdch preinc2 ( 1 ) fbch ccpr1l f9ch pstr1con f7ch tmr5l f5ch rtcvall ffbh pclatu fdbh plusw2 ( 1 ) fbbh ccp1con f9bh osctune f7bh t5con f5bh alrmcfg ffah pclath fdah fsr2h fbah pir5 f9ah trisj ( 2 ) f7ah t5gcon f5ah alrmrpt ff9h pcl fd9h fsr2l fb9h pie5 f99h trish ( 2 ) f79h ccpr4h f59h alrmvalh ff8h tblptru fd8h status fb8h ipr4 f98h trisg f78h ccpr4l f58h alrmvall ff7h tblptrh fd7h tmr0h fb7h pir4 f97h trisf f77h ccp4con f57h ctmuconh ff6h tblptrl fd6h tmr0l fb6h pie4 f96h trise f76h ccpr5h f56h ctmuconl ff5h tablat fd5h t0con fb5h cvrcon f95h trisd f75h ccpr5l f55h ctmuiconh ff4h prodh fd4h spbrgh1 fb4h cmstat f94h trisc f74h ccp5con f54h cm1con ff3h prodl fd3h osccon fb3h tmr3h f93h trisb f73h ccpr6h f53h padcfg1 ff2h intcon fd2h ipr5 fb2h tmr3l f92h trisa f72h ccpr6l f52h eccp2as ff1h intcon2 fd1h wdtcon fb1h t3con f91h latj ( 2 ) f71h ccp6con f51h eccp2del ff0h intcon3 fd0h rcon fb0h t3gcon f90h lath ( 2 ) f70h ccpr7h f50h ccpr2h fefh indf0 ( 1 ) fcfh tmr1h fafh spbrg1 f8fh latg f6fh ccpr7l f4fh ccpr2l feeh postinc0 ( 1 ) fceh tmr1l faeh rcreg1 f8eh latf f6eh ccp7con f4eh ccp2con fedh postdec0 ( 1 ) fcdh t1con fadh txreg1 f8dh late f6dh tmr4 f4dh eccp3as fech preinc0 ( 1 ) fcch tmr2 fach txsta1 f8ch latd f6ch pr4 f4ch eccp3del febh plusw0 ( 1 ) fcbh pr2 fabh rcsta1 f8bh latc f6bh t4con f4bh ccpr3h feah fsr0h fcah t2con faah t1gcon f8ah latb f6ah ssp2buf f4ah ccpr3l fe9h fsr0l fc9h ssp1buf fa9h ipr6 f89h lata f69h ssp2add f49h ccp3con fe8h wreg fc8h ssp1add fa8h hlvdcon f88h portj ( 2 ) f68h ssp2stat f48h ccpr8h fe7h indf1 ( 1 ) fc7h ssp1stat fa7h pspcon f87h porth ( 2 ) f67h ssp2con1 f47h ccpr8l fe6h postinc1 ( 1 ) fc6h ssp1con1 fa6h pir6 f86h portg f66h ssp2con2 f46h ccp8con fe5h postdec1 ( 1 ) fc5h ssp1con2 fa5h ipr3 f85h portf f65h baudcon1 f45h ccpr9h ( 3 ) fe4h preinc1 ( 1 ) fc4h adresh fa4h pir3 f84h porte f64h osccon2 f44h ccpr9l ( 3 ) fe3h plusw1 ( 1 ) fc3h adresl fa3h pie3 f83h portd f63h eeadrh f43h ccp9con ( 3 ) fe2h fsr1h fc2h adcon0 fa2h ipr2 f82h portc f62h eeadr f42h ccpr10h ( 3 ) fe1h fsr1l fc1h adcon1 fa1h pir2 f81h portb f61h eedata f41h ccpr10l ( 3 ) fe0h bsr fc0h adcon2 fa0h pie2 f80h porta f60h pie6 f40h ccp10con ( 3 ) note 1: this is not a physical register. 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . 3: this register is not available on devices with a program memo ry of 32 kbytes (pic18fx5k22). 4: addresses, f16h through f5fh, are also used by sfrs, but ar e not part of the access ram. to access these registers, users must always load the proper bsr value. downloaded from: http:///
pic18f87k22 family ds39960d-page 98 ? 2009-2011 microchip technology inc. f3fh tmr7h ( 3 ) f32h tmr12 ( 3 ) f25h ancon0 f18h pmd1 f3eh tmr7l ( 3 ) f31h pr12 ( 3 ) f24h ancon1 f17h pmd2 f3dh t7con ( 3 ) f30h t12con ( 3 ) f23h ancon2 f16h pmd3 f3ch t7gcon ( 3 ) f2fh cm2con f22h rcsta2 f3bh tmr6 f2eh cm3con f21h txsta2 f3ah pr6 f2dh ccptmrs0 f20h baudcon2 f39h t6con f2ch ccptmrs1 f1fh spbrgh2 f38h tmr8 f2bh ccptmrs2 f1eh spbrg2 f37h pr8 f2ah refocon f1dh rcreg2 f36h t8con f29h odcon1 f1ch txreg2 f35h tmr10 ( 3 ) f28h odcon2 f1bh pstr2con f34h pr10 ( 3 ) f27h odcon3 f1ah pstr3con f33h t10con ( 3 ) f26h memcon ( 3 ) f19h pmd0 table 6-2: pic18f87k22 family register file summary address file name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor fffh tosu top-of-stack upper byte (tos<20:16>) ---0 0000 ffeh tosh top-of-stack high byte (tos<15:8>) 0000 0000 ffdh tosl top-of-stack low byte (tos<7:0>) 0000 0000 ffch stkptr stkful stkunf return stack pointer uu-0 0000 ffbh pclatu holding register for pc<20:16> ---0 0000 ffah pclath holding register for pc<15:8> 0000 0000 ff9h pcl pc low byte (pc<7:0>) 0000 0000 ff8h tblptru bit 21 program memory table pointer upper byte (tblptr<20:16>) --00 0000 ff7h tblptrh program memory table pointer high byte (tblptr<15:8>) 0000 0000 ff6h tblptrl program memory table pointer low byte (tblptr<7:0>) 0000 0000 ff5h tablat program memory table latch 0000 0000 ff4h prodh product register high byte xxxx xxxx ff3h prodl product register low byte xxxx xxxx ff2h intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif 0000 000x ff1h intcon2 rbpu intedg0 intedg1 intedg2 intedg3 tmr0ip int3ip rbip 1111 1111 ff0h intcon3 int2ip int1ip int3ie int2ie int1ie int3if int2if int1if 1100 0000 fefh indf0 uses contents of fsr0 to address data memory C value of fsr0 not changed (not a physical register) ---- ---- feeh postinc0 uses contents of fsr0 to address data memory C value of fsr0 post-incremented (not a physical register) ---- ---- fedh postdec0 uses contents of fsr0 to address data memory C value of fsr0 post-decremented (not a physical register) ---- ---- fech preinc0 uses contents of fsr0 to address data memory C value of fsr0 pre-incremented (not a physical register) ---- ---- febh plusw0 uses contents of fsr0 to address data memory C value of fsr0 pre-incremented (not a physical register) C value of fsr0 offset by w ---- ---- feah fsr0h indirect data memory address pointer 0 high ---- 0000 fe9h fsr0l indirect data memory address pointer 0 low byte xxxx xxxx fe8h wreg working register xxxx xxxx fe7h indf1 uses contents of fsr1 to address data memory C value of fsr1 not changed (not a physical register) ---- ---- note 1: this bit is available when master clear is disabled (mclre = 0 ). when mclre is set, the bit is unimplemented. 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . 3: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). table 6-1: special function register map for pic18f87k22 family (continued) addr. name addr. name addr. name addr. name addr. name addr. name ( 4 ) note 1: this is not a physical register. 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . 3: this register is not available on devices with a program memo ry of 32 kbytes (pic18fx5k22). 4: addresses, f16h through f5fh, are also used by sfrs, but ar e not part of the access ram. to access these registers, users must always load the proper bsr value. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 99 pic18f87k22 family fe6h postinc1 uses contents of fsr1 to address data memory C value of fsr1 post-incremented (not a physical register) ---- ---- fe5h postdec1 uses contents of fsr1 to address data memory C value of fsr1 post-decremented (not a physical register) ---- ---- fe4h preinc1 uses contents of fsr1 to address data memory C value of fsr1 pre-incremented (not a physical register) ---- ---- fe3h plusw1 uses contents of fsr1 to address data memory C value of fsr1 pre-incremented (not a physical register) C value of fsr1 offset by w ---- ---- fe2h fsr1h indirect data memory address pointer 1 high ---- xxxx fe1h fsr1l indirect data memory address pointer 1 low byte xxxx xxxx fe0h bsr bank select register ---- 0000 fdfh indf2 uses contents of fsr2 to address data memory C value of fsr2 not changed (not a physical register) ---- ---- fdeh postinc2 uses contents of fsr2 to address data memory C value of fsr2 post-incremented (not a physical register) ---- ---- fddh postdec2 uses contents of fsr2 to address data memory C value of fsr2 post-decremented (not a physical register) ---- ---- fdch preinc2 uses contents of fsr2 to address data memory C value of fsr2 pre-incremented (not a physical register) ---- ---- fdbh plusw2 uses contents of fsr2 to address data memory C value of fsr2 pre-incremented (not a physi cal register) C value of fsr2 offset by w ---- ---- fdah fsr2h indirect data memory address pointer 2 high ---- xxxx fd9h fsr2l indirect data memory address pointer 2 low byte xxxx xxxx fd8h status no vzd cc ---x xxxx fd7h tmr0h timer0 register high byte 0000 0000 fd6h tmr0l timer0 register low byte xxxx xxxx fd5h t0con tmr0on t08bit t0cs t0se psa tops2 tops1 tops0 1111 1111 fd4h spbrgh1 usart1 baud rate generator high byte 0000 0000 fd3h osccon idlen ircf2 ircf1 ircf0 osts hfiofs scs1 scs0 0110 q000 fd2h ipr5 tmr7gip ( 3 ) tmr12ip ( 3 ) tmr10ip ( 3 ) tmr8ip tmr7ip ( 3 ) tmr6ip tmr5ip tmr4ip 1111 1111 fd1h wdtcon regslp u l p l v ls r e t e n ulpen ulpsink swdten 0-x0 -000 fd0h rcon ipen sboren cm ri to pd por bor 0111 11qq fcfh tmr1h timer1 register high byte xxxx xxxx fceh tmr1l timer1 register low byte xxxx xxxx fcdh t1con tmr1cs1 tmr1cs0 t1ckps1 t1ckps0 soscen t1sync rd16 tmr1on 0000 0000 fcch tmr2 timer2 register 0000 0000 fcbh pr2 timer2 period register 1111 1111 fcah t2con t2outps3 t2outps2 t2outps1 t2outps0 tmr2on t2ckps1 t2ckps0 -000 0000 fc9h ssp1buf mssp receive buffer/transmit register xxxx xxxx fc8h ssp1add mssp address register in i 2 c? slave mode. ssp1 baud rate reload register in i 2 c master mode. 0000 0000 fc7h ssp1stat smp cke d/a psr / w ua bf 0000 0000 fc6h ssp1con1 wcol sspov sspen ckp sspm3 sspm2 sspm1 sspm0 0000 0000 fc5h ssp1con2 gcen ackstat ackdt acken rcen pen rsen sen 0000 0000 fc4h adresh a/d result register high byte xxxx xxxx fc3h adresl a/d result register low byte xxxx xxxx fc2h adcon0 chs4 chs3 chs2 chs1 chs0 go/done adon -000 0000 fc1h adcon1 trigsel1 trigsel0 vcfg1 vcfg0 vncfg chsn2 chsn1 chsn0 0000 0000 fc0h adcon2 adfm acqt2 acqt1 acqt0 adcs2 adcs1 adcs0 0-00 0000 fbfh eccp1as eccp1ase eccp1as2 eccp1as1 eccp1as0 pss1ac1 pss1ac0 pss1bd1 pss1bd0 0000 0000 fbeh eccp1del p1rsen p1dc6 p1dc5 p1dc4 p1dc3 p1dc2 p1dc1 p1dc0 0000 0000 fbdh ccpr1h capture/compare/pwm register1 high byte xxxx xxxx fbch ccpr1l capture/compare/pwm register1 low byte xxxx xxxx fbbh ccp1con p1m1 p1m0 dc1b1 dc1b0 ccp1m3 ccp1m2 ccp1m1 ccp1m0 0000 0000 fbah pir5 tmr7gif ( 3 ) tmr12if ( 3 ) tmr10if ( 3 ) tmr8if tmr7if ( 3 ) tmr6if tmr5if tmr4if 0000 0000 fb9h pie5 tmr7gie ( 3 ) tmr12ie ( 3 ) tmr10ie ( 3 ) tmr8ie tmr7ie ( 3 ) tmr6ie tmr5ie tmr4ie 0000 0000 fb8h ipr4 ccp10ip ( 3 ) ccp9ip ( 3 ) ccp8ip ccp7ip ccp6ip ccp5ip ccp4ip ccp3ip 1111 1111 fb7h pir4 ccp10if ( 3 ) ccp9if ( 3 ) ccp8if ccp7if ccp6if ccp5if ccp4if ccp3if 0000 0000 table 6-2: pic18f87k22 family register file summary (continued) address file name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor note 1: this bit is available when master clear is disabled (mclre = 0 ). when mclre is set, the bit is unimplemented. 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . 3: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
pic18f87k22 family ds39960d-page 100 ? 2009-2011 microchip technology inc. fb6h pie4 ccp10ie ( 3 ) ccp9ie ( 3 ) ccp8ie ccp7ie ccp6ie ccp5ie ccp4ie ccp3ie 0000 0000 fb5h cvrcon cvren cvroe cvrss cvr4 cvr3 cvr2 cvr1 cvr0 0000 0000 fb4h cmstat cmp3out cmp2out cmp1out xxx- ---- fb3h tmr3h timer3 register high byte xxxx xxxx fb2h tmr3l timer3 register low byte xxxx xxxx fb1h t3con tmr3cs1 tmr3cs0 t3ckps1 t3ckps0 soscen t3sync rd16 tmr3on 0000 0000 fb0h t3gcon tmr3ge t3gpol t3gtm t3gspm t3ggo/ t3done t3gval t3gss1 t3gss0 0000 0x00 fafh spbrg1 usart1 baud rate generator 0000 0000 faeh rcreg1 usart1 receive register 0000 0000 fadh txreg1 usart1 transmit register xxxx xxxx fach txsta1 csrc tx9 txen sync sendb brgh trmt tx9d 0000 0010 fabh rcsta1 spen rx9 sren cren adden ferr oerr rx9d 0000 000x faah t1gcon tmr1ge t1gpol t1gtm t1gspm t1ggo/ t1done t1gval t1gss1 t1gss0 0000 0x00 fa9h ipr6 eeip cmp3ip cmp2ip cmp1ip ---1 -111 fa8h hlvdcon vdirmag bgvst irvst hlvden hlvdl3 hlvdl2 hlvdl1 hlvdl0 0000 0000 fa7h pspcon ibf obf ibov pspmode 0000 ---- fa6h pir6 e e i f cmp3if cmp2if cmp1if ---0 -000 fa5h ipr3 tmr5gip rc2ip tx2ip ctmuip ccp2ip ccp1ip rtccip 1-11 1111 fa4h pir3 tmr5gif rc2if tx2if ctmuif ccp2if ccp1if rtccif 0-00 0000 fa3h pie3 tmr5gie rc2ie tx2ie ctmuie ccp2ie ccp1ie rtccie 0-00 0000 fa2h ipr2 oscfip ssp2ip bcl2ip bcl1ip hlvdip tmr3ip tmr3gip 1-11 1111 fa1h pir2 oscfif ssp2if bcl2if bcl1if hlvdif tmr3if tmr3gif 0-00 0000 fa0h pie2 oscfie ssp2ie bcl2ie bcl1ie hlvdie tmr3ie tmr3gie 0-00 0000 f9fh ipr1 pspip adip rc1ip tx1ip ssp1ip tmr1gip tmr2ip tmr1ip 1111 1111 f9eh pir1 pspif adif rc1if tx1if ssp1if tmr1gif tmr2if tmr1if 0000 0000 f9dh pie1 pspie adie rc1ie tx1ie ssp1ie tmr1gie tmr2ie tmr1ie 0000 0000 f9ch pstr1con cmpl1 cmpl0 strsync strd strc strb stra 00-0 0001 f9bh osctune intsrc pllen tun5 tun4 tun3 tun2 tun1 tun0 0000 0000 f9ah trisj ( 2 ) trisj7 trisj6 trisj5 trisj4 trisj3 trisj2 trisj1 trisj0 1111 1111 f99h trish ( 2 ) trish7 trish6 trish5 trish4 trish3 trish2 trish1 trish0 1111 1111 f98h trisg trisg4 trisg3 tri sg2 trisg1 trisg0 ---1 1111 f97h trisf trisf7 trisf6 trisf 5 trisf4 trisf3 trisf2 trisf1 1111 111- f96h trise trise7 trise6 trise5 trise4 trise3 trise2 trise1 1111 111- f95h trisd trisd7 trisd6 trisd5 tri sd4 trisd3 trisd2 trisd1 trisd0 1111 1111 f94h trisc trisc7 trisc6 trisc5 tri sc4 trisc3 trisc2 trisc1 trisc0 1111 1111 f93h trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 1111 1111 f92h trisa trisa7 trisa6 trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 1111 1111 f91h latj ( 2 ) latj7 latj6 latj5 latj4 latj3 latj2 latj1 latj0 xxxx xxxx f90h lath ( 2 ) lath7 lath6 lath5 lath4 lath3 lath2 lath1 lath0 xxxx xxxx f8fh latg latg4 latg3 latg2 latg1 latg0 ---x xxxx f8eh latf latf7 latf6 latf5 latf4 latf3 latf2 latf1 xxxx xxx- f8dh late late7 late6 late5 late4 late3 late2 late1 late0 xxxx xxxx f8ch latd latd7 latd6 latd5 latd4 latd3 latd2 latd1 latd0 xxxx xxxx f8bh latc latc7 latc6 latc5 latc4 latc3 latc2 latc1 latc0 xxxx xxxx f8ah latb latb7 latb6 latb5 latb4 latb3 latb2 latb1 latb0 xxxx xxxx f89h lata lata7 lata6 lata5 lata4 lata3 lata2 lata1 lata0 xxxx xxxx f88h portj ( 2 ) rj7 rj6 rj5 rj4 rj3 rj2 rj1 rj0 xxxx xxxx f87h porth ( 2 ) rh7 rh6 rh5 rh4 rh3 rh2 rh1 rh0 xxxx xxxx table 6-2: pic18f87k22 family register file summary (continued) address file name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor note 1: this bit is available when master clear is disabled (mclre = 0 ). when mclre is set, the bit is unimplemented. 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . 3: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 101 pic18f87k22 family f86h portg r g 5 ( 1 ) rg4 rg3 rg2 rg1 rg0 --xx xxxx f85h portf rf7 rf6 rf5 rf4 rf3 rf2 rf1 xxxx xxx- f84h porte re7 re6 re5 re4 re3 re2 re1 re0 xxxx xxxx f83h portd rd7 rd6 rd5 rd4 rd3 rd2 rd1 rd0 xxxx xxxx f82h portc rc7 rc6 rc5 rc4 rc3 rc2 rc1 rc0 xxxx xxxx f81h portb rb7 rb6 rb5 rb4 rb3 rb2 rb1 rb0 xxxx xxxx f80h porta ra7 ra6 ra5 ra4 ra3 ra2 ra1 ra0 xxxx xxxx f7fh eecon1 eepgd cfgs free wrerr wren wr rd xx-0 x000 f7eh eecon2 eeprom control register 2 (not a physical register) ---- ---- f7dh tmr5h timer5 register high byte xxxx xxxx f7ch tmr5l timer5 register low byte xxxx xxxx f7bh t5con tmr5cs1 tmr5cs0 t5ckps1 t5ckps0 soscen t5sync rd16 tmr5on 0000 0000 f7ah t5gcon tmr5ge t5gpol t5gtm t5gspm t5ggo/ t5done t5gval t5gss1 t5gss0 0000 0x00 f79h ccpr4h capture/compare/pwm register 4 high byte xxxx xxxx f78h ccpr4l capture/compare/pwm register 4 low byte xxxx xxxx f77h ccp4con dc4b1 dc4b0 ccp4m3 ccp4m2 ccp4m1 ccp4m0 --00 0000 f76h ccpr5h capture/compare/pwm register 5 high byte xxxx xxxx f75h ccpr5l capture/compare/pwm register 5 low byte xxxx xxxx f74h ccp5con dc5b1 dc5b0 ccp5m3 ccp5m2 ccp5m1 ccp5m0 --00 0000 f73h ccpr6h capture/compare/pwm register 6 high byte xxxx xxxx f72h ccpr6l capture/compare/pwm register 6 low byte xxxx xxxx f71h ccp6con dc6b1 dc6b0 ccp6m3 ccp6m2 ccp6m1 ccp6m0 --00 0000 f70h ccpr7h capture/compare/pwm register 7 high byte xxxx xxxx f6fh ccpr7l capture/compare/pwm register 7 low byte xxxx xxxx f6eh ccp7con dc7b1 dc7b0 ccp7m3 ccp7m2 ccp7m1 ccp7m0 --00 0000 f6dh tmr4 timer4 register xxxx xxxx f6ch pr4 timer4 period register 1111 1111 f6bh t4con t4outps3 t4outps2 t4outps1 t4outps0 tmr4on t4ckps1 t4ckps0 -111 1111 f6ah ssp2buf mssp receive buffer/transmit register xxxx xxxx f69h ssp2add mssp address register in i 2 c? slave mode. mssp1 baud rate reload register in i 2 c master mode. 0000 0000 f68h ssp2stat smp cke d/a psr / w ua bf 0000 0000 f67h ssp2con1 wcol sspov sspen ckp sspm3 sspm2 sspm1 sspm0 0000 0000 f66h ssp2con2 gcen ackstat ackdt acken rcen pen rsen sen 0100 0000 f65h baudcon1 abdovf rcidl rxdtp txckp brg16 wue abden 0100 0-00 f64h osccon2 soscrun s o s c g o mfiofs mfiosel -0-- 0-x0 f63h eeadrh eeprom address register high byte 0000 0000 f62h eeadr eeprom address register low byte 0000 0000 f61h eedata eeprom data register 0000 0000 f60h pie6 e e i e cmp3ie cmp2ie cmp1ie ---0 -000 f5fh rtccfg rtcen rtcwren rtcsync halfsec rtcoe rtcptr1 rtcptr0 0-00 0000 f5eh rtccal cal7 cal6 cal5 cal4 cal3 cal2 cal1 cal0 0000 0000 f5dh rtcvalh rtcc value high register window based on rtcptr<1:0> xxxx xxxx table 6-2: pic18f87k22 family register file summary (continued) address file name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor note 1: this bit is available when master clear is disabled (mclre = 0 ). when mclre is set, the bit is unimplemented. 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . 3: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
pic18f87k22 family ds39960d-page 102 ? 2009-2011 microchip technology inc. f5ch rtcvall rtcc value low register window based on rtcptr<1:0> 0000 0000 f5bh alrmcfg alrmen chime amask3 amask2 amask1 amask0 alrmptr1 alrmptr0 0000 0000 f5ah alrmrpt arpt7 arpt6 arpt5 arpt4 arpt3 arpt2 arpt1 arpt0 0000 0000 f59h alrmvalh alarm value high register window based on aptr<1:0> xxxx xxxx f58h alrmvall alarm value low register window based on aptr<1:0> xxxx xxxx f57h ctmuconh ctmuen ctmusidl tgen edgen edgseqen idissen cttrig 0-00 0000 f56h ctmuconl edg2pol edg2sel1 edg2sel0 edg1pol edg1sel1 edg1se l0 edg2stat edg1stat 0000 0000 f55h ctmuiconh itrim5 itrim4 itrim3 itrim2 itrim1 itrim0 irng1 irng0 0000 0000 f54h cm1con con coe cpol evpol1 evpol0 cref cch1 cch0 0001 1111 f53h padcfg1 rdpu repu rjpu ( 2 ) rtsecsel1 rtsecsel0 000- -00- f52h eccp2as eccp2ase eccp2as2 eccp2as1 eccp2as0 pss2ac1 pss2ac0 pss2bd1 pss2bd0 0000 0000 f51h eccp2del p2rsen p2dc6 p2dc5 p2dc4 p2dc3 p2dc2 p2dc1 p2dc0 0000 0000 f50h ccpr2h capture/compare/pwm register 2 high byte xxxx xxxx f4fh ccpr2l capture/compare/pwm register 2 low byte xxxx xxxx f4eh ccp2con p2m1 p2m0 dc2b1 dc2b0 ccp2m3 ccp2m2 ccp2m1 ccp2m0 0000 0000 f4dh eccp3as eccp3ase eccp3as2 eccp3as1 eccp3as0 pss3ac1 pss3ac0 pss3bd1 pss3bd0 0000 0000 f4ch eccp3del p3rsen p3dc6 p3dc5 p3dc4 p3dc3 p3dc2 p3dc1 p3dc0 0000 0000 f4bh ccpr3h capture/compare/pwm register 3 high byte xxxx xxxx f4ah ccpr3l capture/compare/pwm register 3 low byte xxxx xxxx f49h ccp3con p3m1 p3m0 dc3b1 dc3b0 ccp3m3 ccp3m2 ccp3m1 ccp3m0 0000 0000 f48h ccpr8h capture/compare/pwm register 8 high byte xxxx xxxx f47h ccpr8l capture/compare/pwm register 8 low byte xxxx xxxx f46h ccp8con dc8b1 dc8b0 ccp8m3 ccp8m2 ccp8m1 ccp8m0 --00 0000 f45h ccpr9h ( 3 ) capture/compare/pwm register 9 high byte xxxx xxxx f44h ccpr9l ( 3 ) capture/compare/pwm register 9 low byte xxxx xxxx f43h ccp9con ( 3 ) dc9b1 dc9b0 ccp9m3 ccp9m2 ccp9m1 ccp9m0 --00 0000 f42h ccpr10h ( 3 ) capture/compare/pwm register 10 high byte xxxx xxxx f41h ccpr10l ( 3 ) capture/compare/pwm register 10 low byte xxxx xxxx f40h ccp10con ( 3 ) dc10b1 dc10b0 ccp10m3 ccp10m2 ccp10m1 ccp10m0 --00 0000 f3fh tmr7h ( 3 ) timer7 register high byte xxxx xxxx f3eh tmr7l ( 3 ) timer7 register low byte 0000 0000 f3dh t7con ( 3 ) tmr7cs1 tmr7cs0 t7ckps1 t7ckps0 soscen t7sync rd16 tmr7on 0000 0000 f3ch t7gcon ( 3 ) tmr7ge t7gpol t7gtm t7gspm t7ggo/ t7done t7gval t7gss1 t7gss0 0000 0x00 f3bh tmr6 timer6 register 0000 0000 f3ah pr6 timer6 period register 1111 1111 f39h t6con t6outps3 t6outps2 t6outps1 t6outps0 tmr6on t6ckps1 t6ckps0 -000 0000 f38h tmr8 timer8 register 0000 0000 f37h pr8 timer8 period register 1111 1111 f36h t8con t8outps3 t8outps2 t8outps1 t8outps0 tmr8on t8ckps1 t8ckps0 -000 0000 f35h tmr10 ( 3 ) tmr10 register 0000 0000 f34h pr10 ( 3 ) timer10 period register 1111 1111 f33h t10con ( 3 ) t10outps3 t10outps2 t10outps1 t10outps0 tmr10on t10ckps1 t10ckps0 -000 0000 f32h tmr12 ( 3 ) tmr12 register 0000 0000 f31h pr12 ( 3 ) timer12 period register 1111 1111 f30h t12con ( 3 ) t12outps3 t12outps2 t12outps1 t12outps0 tmr12on t12ckps1 t12ckps0 -000 0000 f2fh cm2con con coe cpol evpol1 evpol0 cref cch1 cch0 0001 1111 f2eh cm3con con coe cpol evpol1 evpol0 cref cch1 cch0 0001 1111 f2dh ccptmrs0 c3tsel1 c3tsel0 c2tsel2 c2tsel1 c2tsel0 c1tsel2 c1tsel1 c1tsel 0 0000 0000 table 6-2: pic18f87k22 family register file summary (continued) address file name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor note 1: this bit is available when master clear is disabled (mclre = 0 ). when mclre is set, the bit is unimplemented. 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . 3: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 103 pic18f87k22 family f2ch ccptmrs1 c7tsel1 c7tsel0 c6tsel0 c5tsel0 c4tsel1 c4tsel0 00-0 -000 f2bh ccptmrs2 c10tsel0 ( 3 ) c9tsel0 ( 3 ) c8tsel1 c8tsel0 ---0 -000 f2ah refocon roon rosslp rosel rodiv3 rodiv2 rodiv1 rodiv0 0-00 0000 f29h odcon1 ssp1od ccp2od ccp1od ssp2od 000- ---0 f28h odcon2 ccp10od ( 3 ) ccp9od ( 3 ) ccp8od ccp7od ccp6od ccp5od ccp4od ccp3od 0000 0000 f27h odcon3 u2od u1od ctmuds 00-- ---0 f26h memcon (2) ebdis w a i t 1w a i t 0 w m 1w m 0 0-00 --00 f25h ancon0 ansel7 ansel6 ansel5 ansel4 ansel3 ansel2 ansel1 ansel0 1111 1111 f24h ancon1 ansel15 ansel14 ansel13 ansel12 ansel11 ansel10 ansel9 ansel8 1111 1111 f23h ancon2 ansel23 ansel22 ansel21 ansel20 ansel19 ansel18 ansel17 ansel16 1111 1111 f22h rcsta2 spen rx9 sren cren adden ferr oerr rx9d 0000 000x f21h txsta2 csrc tx9 txen sync sendb brgh trmt tx9d 0000 0010 f20h baudcon2 abdovf rcidl rxdtp txckp brg16 wue abden 0100 0-00 f1fh spbrgh2 usart2 baud rate generator high byte 0000 0000 f1eh spbrg2 usart2 baud rate generator 0000 0000 f1dh rcreg2 receive data fifo 0000 0000 f1ch txreg2 transmit data fifo xxxx xxxx f1bh pstr2con cmpl1 cmpl0 strsync strd strc strb stra 00-0 0001 f1ah pstr3con cmpl1 cmpl0 strsync strd strc strb stra 00-0 0001 f19h pmd0 ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd 0000 0000 f18h pmd1 pspmd ctmumd rtccmd tmr4md tmr3md tmr2md tmr1md embmd 0000 0000 f17h pmd2 tmr10md ( 3 ) tmr8md tmr7md ( 3 ) tmr6md tmr5md cmp3md cmp2md cmp1md 0000 0000 f16h pmd3 ccp10md ( 3 ) ccp9md ( 3 ) ccp8md ccp7md ccp6md ccp5md ccp4md tmr12md ( 3 ) 0000 0000 table 6-2: pic18f87k22 family register file summary (continued) address file name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor note 1: this bit is available when master clear is disabled (mclre = 0 ). when mclre is set, the bit is unimplemented. 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . 3: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
pic18f87k22 family ds39960d-page 104 ? 2009-2011 microchip technology inc. 6.3.5 status register the status register, shown in register 6-2 , contains the arithmetic status of the alu. the status register can be the operand for any instruction, as with any other register. if the status register is the destination for an instruction that affects the z, dc, c, ov or n bits, the write to these five bits is disabled. these bits are set or cleared according to the device logic. therefore, the result of an instruction with the status register as destination may be different than intended. for example, clrf status will set the z bit but leave the other bits unchanged. the status register then reads back as 000u u1uu . it is recommended, therefore, that only bcf, bsf, swapf, movff and movwf instructions be used to alter the status register because these instructions do not affect the z, c, dc, ov or n bits in the status register. for other instructions not affecting any status bits, see the instruction set summaries in table 29-2 and table 29-3 . note: the c and dc bits operate, in subtraction, as borrow and digit borrow bits, respectively. register 6-2: status register u-0 u-0 u-0 r/w-x r/w-x r/w-x r/w-x r/w-x no vzd c ( 1 ) c ( 2 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-5 unimplemented: read as 0 bit 4 n: negative bit this bit is used for signed arithmetic (2s complement). it indicates whether the result was negative (alu msb = 1 ). 1 = result was negative 0 = result was positive bit 3 ov: overflow bit this bit is used for signed arithmetic (2s complement). it indicates an overflow of the seven-bit magnitude which causes the sign bit (bit 7) to change state. 1 = overflow occurred for signed arithmetic (in this arithmetic operation) 0 = no overflow occurred bit 2 z: zero bit 1 = the result of an arithmetic or logic operation is zero 0 = the result of an arithmetic or logic operation is not zero bit 1 dc: digit carry/borrow bit ( 1 ) for addwf, addlw, sublw and subwf instructions: 1 = a carry-out from the 4th low-order bit of the result occurred 0 = no carry-out from the 4th low-order bit of the result bit 0 c: carry/borrow bit ( 2 ) for addwf, addlw, sublw and subwf instructions: 1 = a carry-out from the most significant bit of the result occurred 0 = no carry-out from the most significant bit of the result occurred note 1: for borrow, the polarity is reversed. a subtraction is ex ecuted by adding the 2s complement of the second operand. 2: for borrow, the polarity is reversed. a subtraction is executed by adding the 2s complement of the second operand. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 105 pic18f87k22 family 6.4 data addressing modes while the program memory can be addressed in only one way, through the program counter, information in the data memory space can be addressed in several ways. for most instructions, the addressing mode is fixed. other instructions may use up to three modes, depending on which operands are used and whether or not the extended instruction set is enabled. the addressing modes are: inherent literal direct indirect an additional addressing mode, indexed literal offset, is available when the extended instruction set is enabled (xinst configuration bit = 1 ). for details on this modes operation, see section 6.6.1 indexed addressing with literal offset . 6.4.1 inherent and literal addressing many pic18 control instructions do not need any argument at all. they either perform an operation that globally affects the device or they operate implicitly on one register. this addressing mode is known as inherent addressing. examples of this mode include sleep , reset and daw . other instructions work in a similar way, but require an additional explicit argument in the opcode. this method is known as the literal addressing mode because the instructions require some literal value as an argument. examples of this include addlw and movlw , which respectively, add or move a literal value to the w register. other examples include call and goto , which include a 20-bit program memory address. 6.4.2 direct addressing direct addressing specifies all or part of the source and/or destination address of the operation within the opcode itself. the options are specified by the arguments accompanying the instruction. in the core pic18 instruction set, bit-oriented and byte-oriented instructions use some version of direct addressing by default. all of these instructions include some 8-bit literal address as their least significant byte. this address specifies the instructions data source as either a register address in one of the banks of data ram (see section 6.3.3 general purpose register file ) or a location in the access bank (see section 6.3.2 access bank ). the access ram bit, a, determines how the address is interpreted. when a is 1 , the contents of the bsr ( section 6.3.1 bank select register ) are used with the address to determine the complete 12-bit address of the register. when a is 0 , the address is interpreted as being a register in the access bank. addressing that uses the access ram is sometimes also known as direct forced addressing mode. a few instructions, such as movff , include the entire 12-bit address (either source or destination) in their opcodes. in these cases, the bsr is ignored entirely. the destination of the operations results is determined by the destination bit, d. when d is 1 , the results are stored back in the source register, overwriting its origi- nal contents. when d is 0 , the results are stored in the w register. instructions without the d argument have a destination that is implicit in the instruction, either the target register being operated on or the w register. 6.4.3 indirect addressing indirect addressing allows the user to access a location in data memory without giving a fixed address in the instruction. this is done by using file select registers (fsrs) as pointers to the locations to be read or written to. since the fsrs are themselves located in ram as special function registers, they can also be directly manipulated under program control. this makes fsrs very useful in implementing data structures such as tables and arrays in data memory. the registers for indirect addressing are also implemented with indirect file operands (indfs) that permit automatic manipulation of the pointer value with auto-incrementing, auto-decrementing or offsetting with another value. this allows for efficient code using loops, such as the example of clearing an entire ram bank in example 6-5 . it also enables users to perform indexed addressing and other stack pointer operations for program memory in data memory. example 6-5: how to clear ram (bank 1) using indirect addressing note: the execution of some instructions in the core pic18 instruction set are changed when the pic18 extended instruction set is enabled. for more information, see section 6.6 data memory and the extended instruction set . lfsr fsr0, 100h ; next clrf postinc0 ; clear indf ; register then ; inc pointer btfss fsr0h, 1 ; all done with ; bank1? bra next ; no, clear next continue ; yes, continue downloaded from: http:///
pic18f87k22 family ds39960d-page 106 ? 2009-2011 microchip technology inc. 6.4.3.1 fsr registers and the indf operand at the core of indirect addressing are three sets of registers: fsr0, fsr1 and fsr2. each represents a pair of 8-bit registers: fsrnh and fsrnl. the four upper bits of the fsrnh register are not used, so each fsr pair holds a 12-bit value. this represents a value that can address the entire range of the data memory in a linear fashion. the fsr register pairs, then, serve as pointers to data memory locations. indirect addressing is accomplished with a set of indi- rect file operands, indf0 through indf2. these can be thought of as virtual registers. the operands are mapped in the sfr space, but are not physically imple- mented. reading or writing to a particular indf register actually accesses its corresponding fsr register pair. a read from indf1, for example, reads the data at the address indicated by fsr1h:fsr1l. instructions that use the indf registers as operands actually use the contents of their corresponding fsr as a pointer to the instructions target. the indf operand is just a convenient way of using the pointer. because indirect addressing uses a full 12-bit address, data ram banking is not necessary. thus, the current contents of the bsr and the access ram bit have no effect on determining the target address. figure 6-8: indirect addressing fsr1h:fsr1l 0 7 data memory 000h100h 200h 300h f00h e00h fffh bank 0 bank 1 bank 2 bank 14 bank 15 bank 3 through bank 13 addwf, indf1, 1 0 7 using an instruction with one of the indirect addressing registers as the operand.... ...uses the 12-bit address stored in the fsr pair associated with that register.... ...to determine the data memory location to be used in that operation. in this case, the fsr1 pair contains fcch. this means the contents of location, fcch, will be added to that of the w register and stored back in fcch. xxxx 1111 11001100 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 107 pic18f87k22 family 6.4.3.2 fsr registers and postinc, postdec, preinc and plusw in addition to the indf operand, each fsr register pair also has four additional indirect operands. like indf, these are virtual registers that cannot be indirectly read or written to. accessing these registers actually accesses the associated fsr register pair, but also performs a specific action on its stored value. these operands are: postdec C accesses the fsr value, then automatically decrements it by 1 afterwards postinc C accesses the fsr value, then automatically increments it by 1 afterwards preinc C increments the fsr value by 1 , then uses it in the operation plusw C adds the signed value of the w register (range of -127 to 128) to that of the fsr and uses the new value in the operation in this context, accessing an indf register uses the value in the fsr registers without changing them. similarly, accessing a plusw register gives the fsr value, offset by the value in the w register, with neither value actually changed in the operation. accessing the other virtual registers changes the value of the fsr registers. operations on the fsrs with postdec, postinc and preinc affect the entire register pair. rollovers of the fsrnl register, from ffh to 00h, carry over to the fsrnh register. on the other hand, results of these operations do not change the value of any flags in the status register (for example, z, n and ov bits). the plusw register can be used to implement a form of indexed addressing in the data memory space. by manipulating the value in the w register, users can reach addresses that are fixed offsets from pointer addresses. in some applications, this can be used to implement some powerful program control structure, such as software stacks, inside of data memory. 6.4.3.3 operations by fsrs on fsrs indirect addressing operations that target other fsrs or virtual registers represent special cases. for example, using an fsr to point to one of the virtual registers will not result in successful operations. as a specific case, assume that the fsr0h:fsr0l registers contain fe7h, the address of indf1. attempts to read the value of the indf1, using indf0 as an operand, will return 00h. attempts to write to indf1, using indf0 as the operand, will result in a nop . on the other hand, using the virtual registers to write to an fsr pair may not occur as planned. in these cases, the value will be written to the fsr pair, but without any incrementing or decrementing. thus, writing to indf2 or postdec2 will write the same value to the fsr2h:fsr2l. since the fsrs are physical registers mapped in the sfr space, they can be manipulated through all direct operations. users should proceed cautiously when working on these registers, however, particularly if their code uses indirect addressing. similarly, operations by indirect addressing are gener- ally permitted on all other sfrs. users should exercise the appropriate caution, so that they do not inadvertently change settings that might affect the operation of the device. 6.5 program memory and the extended instruction set the operation of program memory is unaffected by the use of the extended instruction set. enabling the extended instruction set adds five additional two-word commands to the existing pic18 instruction set: addfsr , callw , movsf , movss and subfsr . these instructions are executed as described in section 6.2.4 two-word instructions . downloaded from: http:///
pic18f87k22 family ds39960d-page 108 ? 2009-2011 microchip technology inc. 6.6 data memory and the extended instruction set enabling the pic18 extended instruction set (xinst configuration bit = 1 ) significantly changes certain aspects of data memory and its addressing. using the access bank for many of the core pic18 instructions introduces a new addressing mode for the data memory space. this mode also alters the behavior of indirect addressing using fsr2 and its associated operands. what does not change is just as important. the size of the data memory space is unchanged, as well as its linear addressing. the sfr map remains the same. core pic18 instructions can still operate in both direct and indirect addressing mode. inherent and literal instructions do not change at all. indirect addressing with fsr0 and fsr1 also remains unchanged. 6.6.1 indexed addressing with literal offset enabling the pic18 extended instruction set changes the behavior of indirect addressing using the fsr2 register pair and its associated file operands. under the proper conditions, instructions that use the access bank C that is, most bit-oriented and byte-oriented instructions C can invoke a form of indexed addressing using an offset specified in the instruction. this special addressing mode is known as indexed addressing with literal offset or the indexed literal offset mode. when using the extended instruction set, this addressing mode requires the following: use of the access bank (a = 0 ) a file address argument that is less than or equal to 5fh under these conditions, the file address of the instruction is not interpreted as the lower byte of an address (used with the bsr in direct addressing) or as an 8-bit address in the access bank. instead, the value is interpreted as an offset value to an address pointer specified by fsr2. the offset and the contents of fsr2 are added to obtain the target address of the operation. 6.6.2 instructions affected by indexed literal offset mode any of the core pic18 instructions that can use direct addressing are potentially affected by the indexed literal offset addressing mode. this includes all byte-oriented and bit-oriented instructions, or almost one-half of the standard pic18 instruction set. instruc- tions that only use inherent or literal addressing modes are unaffected. additionally, byte-oriented and bit-oriented instructions are not affected if they do not use the access bank (access ram bit = 1 ), or include a file address of 60h or above. instructions meeting these criteria will continue to execute as before. a comparison of the different possible addressing modes when the extended instruction set is enabled is shown in figure 6-9 . those who desire to use byte-oriented or bit-oriented instructions in the indexed literal offset mode should note the changes to assembler syntax for this mode. this is described in more detail in section 29.2.1 extended instruction syntax . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 109 pic18f87k22 family figure 6-9: comparing addressing options for bit-oriented and byte-oriented instructions (extended instruction set enabled) example instruction: addwf, f, d, a (opcode: 0010 01da ffff ffff ) when a = 0 and f ? 60h: the instruction executes in direct forced mode. f is interpreted as a location in the access ram, between 060h and fffh. this is the same as locations, f60h to fffh (bank 15), of data memory. locations below 060h are not available in this addressing mode. when a = 0 and f ??? 5fh: the instruction executes in indexed literal offset mode. f is interpreted as an offset to the address value in fsr2. the two are added together to obtain the address of the target register for the instruction. the address can be anywhere in the data memory space. note that in this mode, the correct syntax is now: addwf [k], d where k is the same as f. when a = 1 (all values of f): the instruction executes in direct mode (also known as direct long mode). f is interpreted as a location in one of the 16 banks of the data memory space. the bank is designated by the bank select register (bsr). the address can be in any implemented bank in the data memory space. 000h 060h 100h f00h f40h fffh valid range 00h 60h ffh data memory access ram bank 0 bank 1 through bank 14 bank 15 sfrs 000h 060h 100h f00h f40h fffh data memory bank 0 bank 1 through bank 14 bank 15 sfrs fsr2h fsr2l ffffffff 001001da ffffffff 001001da 000h 060h 100h f00h f40h fffh data memory bank 0 bank 1 through bank 14 bank 15 sfrs for f bsr 00000000 downloaded from: http:///
pic18f87k22 family ds39960d-page 110 ? 2009-2011 microchip technology inc. 6.6.3 mapping the access bank in indexed literal offset mode the use of indexed literal offset addressing mode effectively changes how the lower part of access ram (00h to 5fh) is mapped. rather than containing just the contents of the bottom part of bank 0, this mode maps the contents from bank 0 and a user-defined window that can be located anywhere in the data memory space. the value of fsr2 establishes the lower boundary of the addresses mapped into the window, while the upper boundary is defined by fsr2 plus 95 (5fh). addresses in the access ram above 5fh are mapped as previously described. (see section 6.3.2 access bank .) an example of access bank remapping in this addressing mode is shown in figure 6-10 . remapping the access bank applies only to operations using the indexed literal offset mode. operations that use the bsr (access ram bit = 1 ) will continue to use direct addressing as before. any indirect or indexed addressing operation that explicitly uses any of the indirect file operands (including fsr2) will continue to operate as standard indirect addressing. any instruc- tion that uses the access bank, but includes a register address of greater than 05fh, will use direct addressing and the normal access bank map. 6.6.4 bsr in indexed literal offset mode although the access bank is remapped when the extended instruction set is enabled, the operation of the bsr remains unchanged. direct addressing, using the bsr to select the data memory bank, operates in the same manner as previously described. figure 6-10: remapping the access bank with indexed literal offset addressing data memory 000h100h 200h f60h f00h fffh bank 1 bank 15 bank 2 through bank 14 sfrs 05fh addwf f, d, a fsr2h:fsr2l = 120h locations in the region from the fsr2 pointer (120h) to the pointer plus 05fh (17fh) are mapped to the bottom of the access ram (000h-05fh). special function registers at f60h through fffh are mapped to 60h through ffh, as usual. bank 0 addresses below 5fh are not available in this mode. they can still be addressed by using the bsr. access bank 00hffh bank 0 sfrs bank 1 window not accessible window example situation: 120h 17fh 5fh 60h downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 111 pic18f87k22 family 7.0 flash program memory the flash program memory is readable, writable and erasable during normal operation over the entire v dd range. a read from program memory is executed on one byte at a time. for execution of a write to, or erasure of, program memory: memory of 32 kbytes and 64 kbytes (pic18fx5k22 and pic18fx6k22 devices) C blocks of 64 bytes memory of 128 kbytes (pic18fx7k22 devices) C blocks of 128 bytes writing or erasing program memory will cease instruction fetches until the operation is complete. the program memory cannot be accessed during the write or erase, therefore, code cannot execute. an internal programming timer terminates program memory writes and erases. a value written to program memory does not need to be a valid instruction. executing a program memory location that forms an invalid instruction results in a nop . 7.1 table reads and table writes in order to read and write program memory, there are two operations that allow the processor to move bytes between the program memory space and the data ram: table read ( tblrd ) table write ( tblwt ) the program memory space is 16 bits wide, while the data ram space is 8 bits wide. table reads and table writes move data between these two memory spaces through an 8-bit register (tablat). table read operations retrieve data from program memory and place it into the data ram space. figure 7-1 shows the operation of a table read with program memory and data ram. table write operations store data from the data memory space into holding registers in program memory. the procedure to write the contents of the holding registers into program memory is detailed in section 7.5 writing to flash program memory . figure 7-2 shows the operation of a table write with program memory and data ram. table operations work with byte entities. a table block containing data, rather than program instructions, is not required to be word-aligned. therefore, a table block can start and end at any byte address. if a table write is being used to write executable code into program memory, program instructions will need to be word-aligned. figure 7-1: table read operation table pointer (1) table latch (8-bit) program memory tblptrh tblptrl tablat tblptru instruction: tblrd * note 1: the table pointer register points to a byte in program memory. program memory (tblptr) downloaded from: http:///
pic18f87k22 family ds39960d-page 112 ? 2009-2011 microchip technology inc. figure 7-2: table write operation 7.2 control registers several control registers are used in conjunction with the tblrd and tblwt instructions. these include the: eecon1 register eecon2 register tablat register tblptr registers 7.2.1 eecon1 and eecon2 registers the eecon1 register ( register 7-1 ) is the control register for memory accesses. the eecon2 register, not a physical register, is used exclusively in the memory write and erase sequences. reading eecon2 will read all 0 s. the eepgd control bit determines if the access is a program or data eeprom memory access. when clear, any subsequent operations operate on the data eeprom memory. when set, any subsequent operations operate on the program memory. the cfgs control bit determines if the access is to the configuration/calibration registers or to program memory/data eeprom memory. when set, subsequent operations operate on configuration registers regardless of eepgd (see section 28.0 special features of the cpu ). when clear, memory selection access is determined by eepgd. the free bit, when set, allows a program memory erase operation. when free is set, the erase operation is initiated on the next wr command. when free is clear, only writes are enabled. the wren bit, when set, allows a write operation. on power-up, the wren bit is clear. the wrerr bit is set in hardware when the wr bit is set and cleared when the internal programming timer expires and the write operation is complete. the wr control bit initiates write operations. the bit cannot be cleared, only set, in software. it is cleared in hardware at the completion of the write operation. table pointer (1) table latch (8-bit) tblptrh tblptrl tablat program memory (tblptr) tblptru instruction: tblwt * note 1: the table pointer actually points to one of 64 holding registers; the address of which is determined by tblptrl<5:0>. the process for physically writing dat a to the program memory array is discussed in section 7.5 writing to flash program memory . holding registers program memory note: during normal operation, the wrerr is read as 1 . this can indicate that a write operation was prematurely terminated by a reset or a write operation was attempted improperly. note: the eeif interrupt flag bit (pir6<4>) is set when the write is complete. it must be cleared in software. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 113 pic18f87k22 family register 7-1: eecon1: eepr om control register 1 r/w-x r/w-x u-0 r/w-0 r/w-x r/w-0 r/s-0 r/s-0 eepgd cfgs free wrerr ( 1 ) wren wr rd bit 7 bit 0 legend: s = settable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 eepgd: flash program or data eeprom memory select bit 1 = access flash program memory 0 = access data eeprom memory bit 6 cfgs: flash program/data eeprom or configuration select bit 1 = access configuration registers 0 = access flash program or data eeprom memory bit 5 unimplemented: read as 0 bit 4 free: flash row erase enable bit 1 = erase the program memory row addressed by tblptr on the next wr command (cleared by completion of erase operation) 0 = perform write-only bit 3 wrerr: flash program/data eeprom error flag bit ( 1 ) 1 = a write operation is prematurely terminated (any reset during self-timed programming in normal operation or an improper write attempt) 0 = the write operation completed bit 2 wren: flash program/data eeprom write enable bit 1 = allows write cycles to flash program/data eeprom 0 = inhibits write cycles to flash program/data eeprom bit 1 wr: write control bit 1 = initiates a data eeprom erase/write cycle or a program memory erase cycle or write cycle (the operation is self-timed and the bit is cleared by hardware once the write is complete. the wr bit can only be set (not cleared) in software.) 0 = write cycle to the eeprom is complete bit 0 rd: read control bit 1 = initiates an eeprom read (read takes one cycle. rd is cleared in hardware. the rd bit can only be set (not cleared) in software. the rd bit cannot be set when eepgd = 1 or cfgs = 1 .) 0 = does not initiate an eeprom read note 1: when a wrerr occurs, the eepgd and cfgs bits are not cleared. this allows tracing of the error condition. downloaded from: http:///
pic18f87k22 family ds39960d-page 114 ? 2009-2011 microchip technology inc. 7.2.2 tablat C table latch register the table latch (tablat) is an eight-bit register mapped into the sfr space. the table latch register is used to hold 8-bit data during data transfers between program memory and data ram. 7.2.3 tblptr C table pointer register the table pointer (tblptr) register addresses a byte within the program memory. the tblptr is comprised of three sfr registers: table pointer upper byte, table pointer high byte and table pointer low byte (tblptru:tblptrh:tblptrl). these three regis- ters join to form a 22-bit wide pointer. the low-order 21 bits allow the device to address up to 2 mbytes of program memory space. the 22nd bit allows access to the device id, the user id and the configuration bits. the table pointer register, tblptr, is used by the tblrd and tblwt instructions. these instructions can update the tblptr in one of four ways, based on the table operation. these operations are shown in table 7-1 and only affect the low-order 21 bits. 7.2.4 table pointer boundaries the tblptr is used in reads, writes and erases of the flash program memory. when a tblrd is executed, all 22 bits of the tblptr determine which byte is read from program memory into the tablat. when a tblwt is executed, the six lsbs of the table pointer register (tblptr<5:0>) determine which of the 64 program memory holding registers is written to. when the timed write to program memory begins (via the wr bit), the 16 msbs of the tblptr (tblptr<21:6>) determine which program memory block of 64 bytes is written to. for more detail, see section 7.5 writing to flash program memory . when an erase of program memory is executed, the 16 msbs of the table pointer register (tblptr<21:6>) point to the 64-byte block that will be erased. the least significant bits (tblptr<5:0>) are ignored. figure 7-3 describes the relevant boundaries of the tblptr based on flash program memory operations. table 7-1: table pointer operations with tblrd and tblwt instructions figure 7-3: table pointer boundaries based on operation example operation on table pointer tblrd* tblwt* tblptr is not modified tblrd*+ tblwt*+ tblptr is incremented after the read/write tblrd*- tblwt*- tblptr is decremented after the read/write tblrd+* tblwt+* tblptr is incremented before the read/write 21 16 15 87 0 table erase/write table write table read C tblptr<21:0> tblptrl tblptrh tblptru tblptr<5:0> tblptr<21:6> downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 115 pic18f87k22 family 7.3 reading the flash program memory the tblrd instruction is used to retrieve data from program memory and places it into data ram. table reads from program memory are performed, one byte at a time. tblptr points to a byte address in program space. executing tblrd places the byte pointed to into tablat. in addition, the tblptr can be modified automatically for the next table read operation. the internal program memory is typically organized by words. the least significant bit of the address selects between the high and low bytes of the word. figure 7-4 shows the interface between the internal program memory and the tablat. figure 7-4: reads from flash program memory example 7-1: reading a flash program memory word (even byte address) program memory (odd byte address) tblrd tablat tblptr = xxxxx1 fetch instruction register (ir) read register tblptr = xxxxx0 bcf eecon1, cfgs ; point to flash program memory bsf eecon1, eepgd ; access flash program memory movlw code_addr_upper ; load tblptr with the base movwf tblptru ; address of the word movlw code_addr_high movwf tblptrh movlw code_addr_low movwf tblptrl read_word tblrd*+ ; read into tablat and increment movf tablat, w ; get data movwf word_even tblrd*+ ; read into tablat and increment movf tablat, w ; get data movf word_odd downloaded from: http:///
pic18f87k22 family ds39960d-page 116 ? 2009-2011 microchip technology inc. 7.4 erasing flash program memory the erase blocks are: pic18fx5k22 and pic18fx6k22 C 32 words or 64 bytes pic18fx7k22 C 64 words or 128 bytes word erase in the flash array is not supported. when initiating an erase sequence from the micro- controller itself, a block of 64 or 128 bytes of program memory is erased. the most significant 16 bits of the tblptr<21:6> point to the block being erased. the tblptr<5:0> bits are ignored. the eecon1 register commands the erase operation. the eepgd bit must be set to point to the flash program memory. the wren bit must be set to enable write operations. the free bit is set to select an erase operation. for protection, the write initiate sequence for eecon2 must be used. a long write is necessary for erasing the internal flash. instruction execution is halted while in a long write cycle. the long write will be terminated by the internal programming timer. 7.4.1 flash program memory erase sequence the sequence of events for erasing a block of internal program memory location is: 1. load the table pointer register with the address of the row to be erased. 2. set the eecon1 register for the erase operation: set the eepgd bit to point to program memory clear the cfgs bit to access program memory set the wren bit to enable writes set the free bit to enable the erase 3. disable the interrupts. 4. write 0x55 to eecon2. 5. write 0xaa to eecon2. 6. set the wr bit. this begins the row erase cycle. the cpu will stall for the duration of the erase for t iw . (see parameter d133a .) 7. re-enable interrupts. example 7-2: erasing a flash program memory row movlw code_addr_upper ; load tblptr with the base movwf tblptru ; address of the memory block movlw code_addr_high movwf tblptrh movlw code_addr_low movwf tblptrl erase_row bsf eecon1, eepgd ; point to flash program memory bcf eecon1, cfgs ; access flash program memory bsf eecon1, wren ; enable write to memory bsf eecon1, free ; enable row erase operation bcf intcon, gie ; disable interrupts required movlw 0x55 sequence movwf eecon2 ; write 55h movlw 0xaa movwf eecon2 ; write 0aah bsf eecon1, wr ; start erase (cpu stall) bsf intcon, gie ; re-enable interrupts downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 117 pic18f87k22 family 7.5 writing to flash program memory the programming blocks are: pic18fx5k22 and pic18fx6k22 C 32 words or 64 bytes pic18fx7k22 C 64 words or 128 bytes word or byte programming is not supported. table writes are used internally to load the holding registers needed to program the flash memory. the number of holding registers used for programming by the table writes are: pic18fx5k22 and pic18fx6k22 C 64 pic18fx7k22 C 128 since the table latch (tablat) is only a single byte, the tblwt instruction may need to be executed 64 times for each programming operation. all of the table write oper- ations will essentially be short writes because only the holding registers are written. at the end of updating the 64 or 128 holding registers, the eecon1 register must be written to in order to start the programming operation with a long write. the long write is necessary for programming the internal flash. instruction execution is halted while in a long write cycle. the long write is terminated by the internal programming timer. the eeprom on-chip timer controls the write time. the write/erase voltages are generated by an on-chip charge pump, rated to operate over the voltage range of the device. figure 7-5: table writes to flash program memory note: the default value of the holding registers on device resets, and after write opera- tions, is ffh. a write of ffh to a holding register does not modify that byte. this means that individual bytes of program memory may be modified, provided that the change does not attempt to change any bit from a 0 to a 1 . when modifying individual bytes, it is not necessary to load all 64 or 128 holding registers before executing a write operation. tablat tblptr = xxxx3f tblptr = xxxxx1 tblptr = xxxxx0 write register tblptr = xxxxx2 program memory holding register holding register holding register holding register 8 8 8 8 downloaded from: http:///
pic18f87k22 family ds39960d-page 118 ? 2009-2011 microchip technology inc. 7.5.1 flash program memory write sequence the sequence of events for programming an internal program memory location should be: 1. read the 64 or 128 bytes into ram. 2. update the data values in ram as necessary. 3. load the table pointer register with the address being erased. 4. execute the row erase procedure. 5. load the table pointer register with the address of the first byte being written. 6. write the 64 or 128 bytes into the holding registers with auto-increment. 7. set the eecon1 register for the write operation: set the eepgd bit to point to program memory clear the cfgs bit to access program memory set the wren to enable byte writes 8. disable the interrupts. 9. write 0x55 to eecon2. 10. write 0xaa to eecon2. 11. set the wr bit. this will begin the write cycle. the cpu will stall for duration of the write for t iw (see parameter d133a ). 12. re-enable the interrupts. 13. verify the memory (table read). an example of the required code is shown in example 7-3 . note: before setting the wr bit, the table pointer address needs to be within the intended address range of the 64 or 128 bytes in the holding register. note: self-write execution to flash and eeprom memory cannot be done while running in lp oscillator mode (low-power mode). therefore, executing a self-write will put the device into high-power mode. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 119 pic18f87k22 family example 7-3: writing to flash program memory movlw size_of_block ; number of bytes in erase block movwf counter movlw buffer_addr_high ; point to buffer movwf fsr0h movlw buffer_addr_low movwf fsr0l movlw code_addr_upper ; load tblptr with the base movwf tblptru ; address of the memory block movlw code_addr_high movwf tblptrh movlw code_addr_low movwf tblptrl read_block tblrd*+ ; read into tablat, and inc movf tablat, w ; get data movwf postinc0 ; store data decfsz counter ; done? bra read_block ; repeat modify_word movlw data_addr_high ; point to buffer movwf fsr0h movlw data_addr_low movwf fsr0l movlw new_data_low ; update buffer word movwf postinc0 movlw new_data_high movwf indf0 erase_block movlw code_addr_upper ; load tblptr with the base movwf tblptru ; address of the memory block movlw code_addr_high movwf tblptrh movlw code_addr_low movwf tblptrl bsf eecon1, eepgd ; point to flash program memory bcf eecon1, cfgs ; access flash program memory bsf eecon1, wren ; enable write to memory bsf eecon1, free ; enable row erase operation bcf intcon, gie ; disable interrupts movlw 0x55 required movwf eecon2 ; write 55h sequence movlw 0xaa movwf eecon2 ; write 0aah bsf eecon1, wr ; start erase (cpu stall) bsf intcon, gie ; re-enable interrupts tblrd*- ; dummy read decrement movlw buffer_addr_high ; point to buffer movwf fsr0h movlw buffer_addr_low movwf fsr0l write_buffer_back movlw size_of_block ; number of bytes in holding register movwf counter write_byte_to_hregs movff postinc0, wreg ; get low byte of buffer data movwf tablat ; present data to table latch tblwt+* ; write data, perform a short write ; to internal tblwt holding register. decfsz counter ; loop until buffers are full bra write_byte_to_hregs downloaded from: http:///
pic18f87k22 family ds39960d-page 120 ? 2009-2011 microchip technology inc. example 7-3: writing to flash program memory (continued) 7.5.2 write verify depending on the application, good programming practice may dictate that the value written to the memory should be verified against the original value. this should be used in applications where excessive writes can stress bits near the specification limit. 7.5.3 unexpected termination of write operation if a write is terminated by an unplanned event, such as loss of power or an unexpected reset, the memory location just programmed should be verified and repro- grammed if needed. if the write operation is interrupted by a mclr reset or a wdt time-out reset during normal operation, the user can check the wrerr bit and rewrite the location(s) as needed. 7.5.4 protection against spurious writes to protect against spurious writes to flash program memory, the write initiate sequence must also be followed. see section 28.0 special features of the cpu for more details. 7.6 flash program operation during code protection see section 28.6 program verification and code protection for details on code protection of flash program memory. table 7-2: registers associated with program flash memory program_memory bsf eecon1, eepgd ; point to flash program memory bcf eecon1, cfgs ; access flash program memory bsf eecon1, wren ; enable write to memory bcf intcon, gie ; disable interrupts movlw 0x55 required movwf eecon2 ; write 55h sequence movlw 0xaa movwf eecon2 ; write 0aah bsf eecon1, wr ; start program (cpu stall) bsf intcon, gie ; re-enable interrupts bcf eecon1, wren ; disable write to memory name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 tblptru b i t 2 1 ( 1 ) program memory table pointer upper byte (tblptr<20:16>) tbpltrh program memory table pointer high byte (tblptr<15:8>) tblptrl program memory table pointer low byte (tblptr<7:0>) tablat program memory table latch intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif eecon2 eeprom control register 2 (not a physical register) eecon1 eepgd cfgs free wrerr wren wr rd ipr6 eeip cmp3ip cmp2ip cmp1ip pir6 eeif cmp3if cmp2if cmp1if pie6 eeie cmp3ie cmp2ie cmp1ie legend: = unimplemented, read as 0 . shaded cells are not used during flash/eeprom access. note 1: bit 21 of the tblptru allows access to the device configuration bits. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 121 pic18f87k22 family 8.0 external memory bus the external memory bus (emb) allows the device to access external memory devices (such as flash, eprom or sram) as program or data memory. it supports both 8 and 16-bit data width modes and three address widths of up to 20 bits. the bus is implemented with 28 pins, multiplexed across four i/o ports. three ports (portd, porte and porth) are multiplexed with the address/data bus for a total of 20 available lines, while portj is multiplexed with the bus control signals. a list of the pins and their functions is provided in table 8-1 . table 8-1: pic18f87k22 family exte rnal bus C i/o po rt functions note: the external memory bus is not implemented on 64-pin devices. name port bit external memory bus function rd0/ad0 portd 0 address bit 0 or data bit 0 rd1/ad1 portd 1 address bit 1 or data bit 1 rd2/ad2 portd 2 address bit 2 or data bit 2 rd3/ad3 portd 3 address bit 3 or data bit 3 rd4/ad4 portd 4 address bit 4 or data bit 4 rd5/ad5 portd 5 address bit 5 or data bit 5 rd6/ad6 portd 6 address bit 6 or data bit 6 rd7/ad7 portd 7 address bit 7 or data bit 7 re0/ad8 porte 0 address bit 8 or data bit 8 re1/ad9 porte 1 address bit 9 or data bit 9 re2/ad10 porte 2 address bit 10 or data bit 10 re3/ad11 porte 3 address bit 11 or data bit 11 re4/ad12 porte 4 address bit 12 or data bit 12 re5/ad13 porte 5 address bit 13 or data bit 13 re6/ad14 porte 6 address bit 14 or data bit 14 re7/ad15 porte 7 address bit 15 or data bit 15 rh0/a16 porth 0 address bit 16 rh1/a17 porth 1 address bit 17 rh2/a18 porth 2 address bit 18 rh3/a19 porth 3 address bit 19 rj0/ale portj 0 address latch enable (ale) control pin rj1/oe portj 1 output enable (oe ) control pin rj2/wrl portj 2 write low (wrl ) control pin rj3/wrh portj 3 write high (wrh ) control pin rj4/ba0 portj 4 byte address bit 0 (ba0) rj5/ce portj 5 chip enable (ce ) control pin rj6/lb portj 6 lower byte enable (lb ) control pin rj7/ub portj 7 upper byte enable (ub ) control pin note: for the sake of clarity, only i/o port and external bus assignments are shown here. one or more additional multiplexed features may be available on some pins. downloaded from: http:///
pic18f87k22 family ds39960d-page 122 ? 2009-2011 microchip technology inc. 8.1 external memory bus control the operation of the interface is controlled by the memcon register ( register 8-1 ). this register is available in all program memory operating modes except microcontroller mode. in this mode, the register is disabled and cannot be written to. the ebdis bit (memcon<7>) controls the operation of the bus and related port functions. clearing ebdis enables the interface and disables the i/o functions of the ports, as well as any other functions multiplexed to those pins. setting the bit enables the i/o ports and other functions, but allows the interface to override everything else on the pins when an external memory operation is required. by default, the external bus is always enabled and disables all other i/o. the operation of the ebdis bit is also influenced by the program memory mode being used. this is discussed in more detail in section 8.5 program memory modes and the external memory bus . the wait bits allow for the addition of wait states to external memory operations. the use of these bits is discussed in section 8.3 wait states . the wm bits select the particular operating mode used when the bus is operating in 16-bit data width mode. these bits are discussed in more detail in section 8.6 16-bit data width modes . these bits have no effect when an 8-bit data width mode is selected. register 8-1: memcon: external memory bus control register ( 1 ) r/w-0 u-0 r/w-0 r/w-0 u-0 u-0 r/w-0 r/w-0 ebdis w a i t 1w a i t 0 w m 1w m 0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 ebdis : external bus disable bit 1 = external bus is enabled when microcontroller accesses external memory; otherwise, all external bus drivers are mapped as i/o ports 0 = external bus is always enabled, i/o ports are disabled bit 6 unimplemented : read as 0 bit 5-4 wait<1:0>: table reads and writes bus cycle wait count bits 11 = table reads and writes will wait 0 t cy 10 = table reads and writes will wait 1 t cy 01 = table reads and writes will wait 2 t cy 00 = table reads and writes will wait 3 t cy bit 3-2 unimplemented : read as 0 bit 1-0 wm<1:0>: tblwt operation with 16-bit data bus width select bits 1x = word write mode: tablat word output; wrh is active when tablat is written 01 = byte select mode: tablat data is copied on both msb and lsb; wrh and (ub or lb ) will activate 00 = byte write mode: tablat data is copied on both msb and lsb; wrh or wrl will activate note 1: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 123 pic18f87k22 family 8.2 address and data width the pic18f87k22 family of devices can be indepen- dently configured for different address and data widths on the same memory bus. both address and data width are set by configuration bits in the config3l register. as configuration bits, this means that these options can only be configured by programming the device and are not controllable in software. the bw bit selects an 8-bit or 16-bit data bus width. setting this bit (default) selects a data width of 16 bits. the abw<1:0> bits determine both the program mem- ory operating mode and the address bus width. the available options are 20-bit, 16-bit and 12-bit, as well as microcontroller mode (external bus is disabled). selecting a 16-bit or 12-bit width makes a correspond- ing number of high-order lines available for i/o functions. these pins are no longer affected by the setting of the ebdis bit. for example, selecting a 16-bit addressing mode (abw<1:0> = 01 ) disables a<19:16> and allows porth<3:0> to function without interruptions from the bus. using the smaller address widths allows users to tailor the memory bus to the size of the external memory space for a particular design while freeing up pins for dedicated i/o operation. because the abw bits have the effect of disabling pins for memory bus operations, it is important to always select an address width at least equal to the data width. if a 12-bit address width is used with a 16-bit data width, the upper four bits of data will not be available on the bus. all combinations of address and data widths require multiplexing of address and data information on the same lines. the address and data multiplexing, as well as i/o ports made available by the use of smaller address widths, are summarized in ta b l e 8 - 2 . 8.2.1 address shifting on the external bus by default, the address presented on the external bus is the value of the pc. in practical terms, this means that addresses in the external memory device, below the top of on-chip memory, are unavailable to the microcontroller. to access these physical locations, the glue logic between the microcontroller and the external memory must somehow translate addresses. to simplify the interface, the external bus offers an extension of extended microcontroller mode that automatically performs address shifting. this feature is controlled by the eashft configuration bit. setting this bit offsets addresses on the bus by the size of the microcontrollers on-chip program memory and sets the bottom address at 0000h. this allows the device to use the entire range of physical addresses of the external memory. 8.2.2 21-bit addressing as an extension of 20-bit address width operation, the external memory bus can also fully address a 2-mbyte memory space. this is done by using the bus address bit 0 (ba0) control line as the least significant bit of the address. the ub and lb control signals may also be used with certain memory devices to select the upper and lower bytes within a 16-bit wide data word. this addressing mode is available in both 8-bit and certain 16-bit data width modes. additional details are provided in section 8.6.3 16-bit byte select mode and section 8.7 8-bit data width mode . table 8-2: address and data lines for different address and data widths data width address width multiplexed data and address lines (and corresponding ports) address only lines (and corresponding ports) ports available for i/o 8-bit 12-bit ad<7:0> (portd<7:0>) ad<11:8> (porte<3:0>) porte<7:4>, all of porth 16-bit ad<15:8> (porte<7:0>) all of porth 20-bit a<19:16>, ad<15:8> (porth<3:0>, porte<7:0>) 16-bit 16-bit ad<15:0> (portd<7:0>, porte<7:0>) all of porth 20-bit a<19:16> (porth<3:0>) downloaded from: http:///
pic18f87k22 family ds39960d-page 124 ? 2009-2011 microchip technology inc. 8.3 wait states while it may be assumed that external memory devices will operate at the microcontroller clock rate, this is often not the case. in fact, many devices require longer times to write or retrieve data than the time allowed by the execution of table read or table write operations. to compensate for this, the external memory bus can be configured to add a fixed delay to each table opera- tion using the bus. wait states are enabled by setting the wait configuration bit. when enabled, the amount of delay is set by the wait<1:0> bits (memcon<5:4>). the delay is based on multiples of microcontroller instruction cycle time and is added following the instruction cycle when the table operation is executed. the range is from no delay to 3 t cy (default value). 8.4 port pin weak pull-ups with the exception of the upper address lines, a<19:16>, the pins associated with the external mem- ory bus are equipped with weak pull-ups. the pull-ups are controlled by the upper three bits of the padcfg1 register (padcfg1<7:5>). they are named rdpu, repu and rjpu, and control pull-ups on portd, porte and portj, respectively. setting one of these bits enables the corresponding pull-ups for that port. all pull-ups are disabled by default on all device resets. in extended microcontroller mode, the port pull-ups can be useful in preserving the memory state on the external bus while the bus is temporarily disabled (ebdis = 1 ). 8.5 program memory modes and the external memory bus the pic18f87k22 family of devices is capable of operating in one of two program memory modes, using combinations of on-chip and external program memory. the functions of the multiplexed port pins depend on the program memory mode selected, as well as the setting of the ebdis bit. in microcontroller mode, the bus is not active and the pins have their port functions only. writes to the memcom register are not permitted. the reset value of ebdis ( 0 ) is ignored and the abw pins behave as i/o ports. in extended microcontroller mode, the external program memory bus shares i/o port functions on the pins. when the device is fetching or doing table read/table write operations on the external program memory space, the pins will have the external bus function. if the device is fetching and accessing internal program memory locations only, the ebdis control bit will change the pins from external memory to i/o port functions. when ebdis = 0 , the pins function as the external bus. when ebdis = 1 , the pins function as i/o ports. if the device fetches or accesses external memory while ebdis = 1 , the pins will switch to the external bus. if the ebdis bit is set by a program executing from external memory, the action of setting the bit will be delayed until the program branches into the internal memory. at that time, the pins will change from external bus to i/o ports. if the device is executing out of internal memory when ebdis = 0 , the memory bus address/data and control pins will not be active. they will go to a state where the active address/data pins are tri-state, the ce , oe , wrh , wrl , ub and lb signals are 1 , and ale and ba0 are 0 . note that only those pins associated with the current address width are forced to tri-state; the other pins continue to function as i/o. in the case of 16-bit address width, for example, only ad<15:0> (portd and porte) are affected; a<19:16> (porth<3:0>) continue to function as i/o. in all external memory modes, the bus takes priority over any other peripherals that may share pins with it. this includes the parallel master port (pmp) and serial communication modules which would otherwise take priority over the i/o port. 8.6 16-bit data width modes in 16-bit data width mode, the external memory interface can be connected to external memories in three different configurations: 16-bit byte write 16-bit word write 16-bit byte select the configuration to be used is determined by the wm<1:0> bits in the memcon register (memcon<1:0>). these three different configurations allow the designer maximum flexibility in using both 8-bit and 16-bit devices with 16-bit data. for all 16-bit modes, the address latch enable (ale) pin indicates that the address bits, ad<15:0>, are available on the external memory interface bus. follow- ing the address latch, the output enable (oe ) signal will enable both bytes of program memory at once to form a 16-bit instruction word. the chip enable (ce signal) is active at any time that the microcontroller accesses external memory, whether reading or writing; it is inactive (asserted high) whenever the device is in sleep mode. in byte select mode, jedec standard flash memories will require ba0 for the byte address line and one i/o line to select between byte and word mode. the other 16-bit modes do not need ba0. jedec standard static ram memories will use the ub or lb signals for byte selection. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 125 pic18f87k22 family 8.6.1 16-bit byte write mode figure 8-1 shows an example of 16-bit byte write mode for pic18f87k22 family devices. this mode is used for two separate 8-bit memories connected for 16-bit operation. this generally includes basic eprom and flash devices. it allows table writes to byte-wide external memories. during a tblwt instruction cycle, the tablat data is presented on the upper and lower bytes of the ad<15:0> bus. the appropriate wrh or wrl control line is strobed on the lsb of the tblptr. figure 8-1: 16-bit byte write mode example ad<7:0> a<19:16> (1) ale d<15:8> 373 a d<7:0> a<19:0> a d<7:0> 373 oe wrh oe oe wr (2) wr (2) ce ce note 1: upper order address lines are used only for 20-bit address widths. 2: this signal only applies to table writes. see section 7.1 table reads and table writes . wrl d<7:0> (lsb) (msb) d<7:0> ad<15:8> address bus data bus control lines ce pic18f87k22 downloaded from: http:///
pic18f87k22 family ds39960d-page 126 ? 2009-2011 microchip technology inc. 8.6.2 16-bit word write mode figure 8-2 shows an example of 16-bit word write mode for pic18f87k22 family devices. this mode is used for word-wide memories, which includes some of the eprom and flash type memories. this mode allows opcode fetches and table reads from all forms of 16-bit memory, and table writes to any type of word-wide external memories. this method makes a distinction between tblwt cycles to even or odd addresses. during a tblwt cycle to an even address (tblptr<0> = 0 ), the tablat data is transferred to a holding latch and the external address data bus is tri-stated for the data portion of the bus cycle. no write signals are activated. during a tblwt cycle to an odd address (tblptr<0> = 1 ), the tablat data is presented on the upper byte of the ad<15:0> bus. the contents of the holding latch are presented on the lower byte of the ad<15:0> bus. the wrh signal is strobed for each write cycle; the wrl pin is unused. the signal on the ba0 pin indicates the lsb of the tblptr, but it is left unconnected. instead, the ub and lb signals are active to select both bytes. the obvious limitation to this method is that the table write must be done in pairs on a specific word boundary to correctly write a word location. figure 8-2: 16-bit word write mode example ad<7:0> ad<15:8> ale 373 a<20:1> 373 oe wrh a<19:16> (1) a d<15:0> oe wr (2) ce d<15:0> jedec word eprom memory address bus data bus control lines note 1: upper order address lines are used only for 20-bit address widths. 2: this signal only applies to table writes. see section 7.1 table reads and table writes . ce pic18f87k22 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 127 pic18f87k22 family 8.6.3 16-bit byte select mode figure 8-3 shows an example of 16-bit byte select mode. this mode allows table write operations to word-wide external memories with byte selection capability. this generally includes both word-wide flash and sram devices. during a tblwt cycle, the tablat data is presented on the upper and lower byte of the ad<15:0> bus. the wrh signal is strobed for each write cycle; the wrl pin is not used. the ba0 or ub /lb signals are used to select the byte to be written, based on the least significant bit of the tblptr register. flash and sram devices use different control signal combinations to implement byte select mode. jedec standard flash memories require that a controller i/o port pin be connected to the memorys byte/word pin to provide the select signal. they also use the ba0 signal from the controller as a byte address. jedec standard static ram memories, on the other hand, use the ub or lb signals to select the byte. figure 8-3: 16-bit byte select mode example ad<7:0> ad<15:8> ale 373 a<20:1> 373 oe wrh a<19:16> (2) wrl ba0 jedec word a d<15:0> a<20:1> ce d<15:0> i/o oe wr (1) a0 byte/word flash memory jedec word a d<15:0> ce d<15:0> oe wr (1) lb ub sram memory lb ub 138 (3) address bus data bus control lines note 1: this signal only applies to table writes. see section 7.1 table reads and table writes . 2: upper order address lines are us ed only for 20-bit address width. 3: demultiplexing is only required when multiple memory devices are accessed. pic18f87k22 downloaded from: http:///
pic18f87k22 family ds39960d-page 128 ? 2009-2011 microchip technology inc. 8.6.4 16-bit mode timing the presentation of control signals on the external memory bus is different for the various operating modes. typical signal timing diagrams are shown in figure 8-4 and figure 8-5 . figure 8-4: external me mory bus timing for tblrd (extended microcont roller mode) figure 8-5: external me mory bus timing for sleep (extended microco ntroller mode) q2 q1 q3 q4 q2 q1 q3 q4 q2 q1 q3 q4 a<19:16> ale oe ad<15:0> ce opcode fetch opcode fetch opcode fetch tblrd * tblrd cycle 1 addlw 55h from 000100h q2 q1 q3 q4 0ch cf33h tblrd 92h from 199e67h 9256h from 000104h memory cycle instruction execution inst(pc C 2) tblrd cycle 2 movlw 55h from 000102h movlw q2 q1 q3 q4 q2 q1 q3 q4 a<19:16> ale oe 3aaah ad<15:0> 00h 00h ce opcode fetch opcode fetch sleep sleep from 007554h q1 bus inactive 0003h 3aabh 0e55h memory cycle instruction execution inst(pc C 2) sleep mode, movlw 55h from 007556h downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 129 pic18f87k22 family 8.7 8-bit data width mode in 8-bit data width mode, the external memory bus operates only in multiplexed mode; that is, data shares the 8 least significant bits of the address bus. figure 8-6 shows an example of 8-bit multiplexed mode for pic18f8xk22 devices. this mode is used for a single, 8-bit memory connected for 16-bit operation. the instructions will be fetched as two 8-bit bytes on a shared data/address bus. the two bytes are sequen- tially fetched within one instruction cycle (t cy ). therefore, the designer must choose external memory devices according to timing calculations based on 1/2 t cy (2 times the instruction rate). for proper mem- ory speed selection, glue logic propagation delay times must be considered, along with setup and hold times. the address latch enable (ale) pin indicates that the address bits, ad<15:0>, are available on the external memory bus interface. the output enable (oe ) signal will enable one byte of program memory for a portion of the instruction cycle, then ba0 will change and the second byte will be enabled to form the 16-bit instruc- tion word. the least significant bit of the address, ba0, must be connected to the memory devices in this mode. the chip enable (ce ) signal is active at any time that the microcontroller accesses external memory, whether reading or writing. it is inactive (asserted high) whenever the device is in sleep mode. this generally includes basic eprom and flash devices. it allows table writes to byte-wide external memories. during a tblwt instruction cycle, the tablat data is presented on the upper and lower bytes of the ad<15:0> bus. the appropriate level of the ba0 control line is strobed on the lsb of the tblptr. figure 8-6: 8-bit multiplexed mode example ad<7:0> a<19:16> (1) ale d<15:8> 373 a<19:0> a d<7:0> oe oe wr (2) ce note 1: upper order address bits are only used for 20-bit address width. the upp er ad byte is used for all address widths except 8-bit. 2: this signal only applies to table writes. see section 7.1 table reads and table writes . wrl d<7:0> ad<15:8> (1) address bus data bus control lines ce a0 ba0 pic18f87k22 downloaded from: http:///
pic18f87k22 family ds39960d-page 130 ? 2009-2011 microchip technology inc. 8.7.1 8-bit mode timing the presentation of control signals on the external memory bus is different for the various operating modes. typical signal timing diagrams are shown in figure 8-7 and figure 8-8 . figure 8-7: external me mory bus timing for tblrd (extended microcont roller mode) figure 8-8: external memo ry bus timing for sleep (extended microcont roller mode) q2 q1 q3 q4 q2 q1 q3 q4 q2 q1 q3 q4 a<19:16> ale oe ad<7:0> ce opcode fetch opcode fetch opcode fetch tblrd * tblrd cycle 1 addlw 55h from 000100h q2 q1 q3 q4 0ch 33h tblrd 92h from 199e67h 92h from 000104h memory cycle instruction execution inst(pc C 2) tblrd cycle 2 movlw 55h from 000102h movlw ad<15:8> cfh q2 q1 q3 q4 q2 q1 q3 q4 a<19:16> ale oe aah ad<7:0> 00h 00h ce opcode fetch opcode fetch sleep sleep from 007554h q1 bus inactive 00h abh 55h memory cycle instruction execution inst(pc C 2) sleep mode, movlw 55h from 007556h ad<15:8> 3ah 3ah 03h 0eh ba0 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 131 pic18f87k22 family 8.8 operation in power-managed modes in alternate, power-managed run modes, the external bus continues to operate normally. if a clock source with a lower speed is selected, bus operations will run at that speed. in these cases, excessive access times for the external memory may result if wait states have been enabled and added to external memory opera- tions. if operations in a lower power run mode are anticipated, users should provide in their applications for adjusting memory access times at the lower clock speeds. in sleep and idle modes, the microcontroller core does not need to access data; bus operations are suspended. the state of the external bus is frozen, with the address/data pins, and most of the control pins, holding at the same state they were in when the mode was invoked. the only potential changes are to the ce , lb and ub pins, which are held at logic high. table 8-3: registers associated with the external memory bus name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 memcon ( 1 ) ebdis w a i t 1w a i t 0 w m 1w m 0 padcfg1 rdpu repu rjpu ( 1 ) rtsecsel1 rtsecsel0 pmd1 pspmd ctmumd rtccmd tmr4md tmr3md tmr2md tmr1md embmd legend: = unimplemented, read as 0 . shaded cells are not used during external memory bus access. note 1: unimplemented in 64-pin devices (pic18f6xk22), read as 0 . downloaded from: http:///
pic18f87k22 family ds39960d-page 132 ? 2009-2011 microchip technology inc. notes: downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 133 pic18f87k22 family 9.0 data eeprom memory the data eeprom is a nonvolatile memory array, separate from the data ram and program memory, that is used for long-term storage of program data. it is not directly mapped in either the register file or program memory space, but is indirectly addressed through the special function registers (sfrs). the eeprom is readable and writable during normal operation over the entire v dd range. five sfrs are used to read and write to the data eeprom, as well as the program memory. they are: eecon1 eecon2 eedata eeadr eeadrh the data eeprom allows byte read and write. when interfacing to the data memory block, eedata holds the 8-bit data for read/write and the eeadrh:eeadr register pair holds the address of the eeprom location being accessed. the eeprom data memory is rated for high erase/write cycle endurance. a byte write automatically erases the location and writes the new data (erase-before-write). the write time is controlled by an on-chip timer; it will vary with voltage and temperature, as well as from chip- to-chip. please refer to parameter d122 ( table 31-1 in section 31.0 electrical characteristics ) for exact limits. 9.1 eeadr and eeadrh registers the eeadrh:eeadr register pair is used to address the data eeprom for read and write operations. eeadrh holds the two msbs of the address; the upper 6 bits are ignored. the 10-bit range of the pair can address a memory range of 1024 bytes (00h to 3ffh). 9.2 eecon1 and eecon2 registers access to the data eeprom is controlled by two registers: eecon1 and eecon2. these are the same registers which control access to the program memory and are used in a similar manner for the data eeprom. the eecon1 register ( register 9-1 ) is the control register for data and program memory access. control bit, eepgd, determines if the access will be to program memory or data eeprom memory. when clear, operations will access the data eeprom memory. when set, program memory is accessed. control bit, cfgs, determines if the access will be to the configuration registers or to program memory/data eeprom memory. when set, subsequent operations access configuration registers. when cfgs is clear, the eepgd bit selects either program flash or data eeprom memory. the wren bit, when set, will allow a write operation. on power-up, the wren bit is clear. the wrerr bit is set in hardware when the wren bit is set, and cleared, when the internal programming timer expires and the write operation is complete. the wr control bit initiates write operations. the bit cannot be cleared, only set, in software. it is cleared in hardware at the completion of the write operation. control bits, rd and wr, start read and erase/write operations, respectively. these bits are set by firmware and cleared by hardware at the completion of the operation. the rd bit cannot be set when accessing program memory (eepgd = 1 ). program memory is read using table read instructions. see section 7.1 table reads and table writes regarding table reads. the eecon2 register is not a physical register. it is used exclusively in the memory write and erase sequences. reading eecon2 will read all 0 s. note: during normal operation, the wrerr is read as 1 . this can indicate that a write operation was prematurely terminated by a reset or a write operation was attempted improperly. note: the eeif interrupt flag bit (pir6<4>) is set when the write is complete; it must be cleared in software. downloaded from: http:///
pic18f87k22 family ds39960d-page 134 ? 2009-2011 microchip technology inc. register 9-1: eecon1: data eeprom control register 1 r/w-x r/w-x u-0 r/w-0 r/w-x r/w-0 r/s-0 r/s-0 eepgd cfgs free wrerr ( 1 ) wren wr rd bit 7 bit 0 legend: s = settable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 eepgd: flash program or data eeprom memory select bit 1 = access flash program memory 0 = access data eeprom memory bit 6 cfgs: flash program/data eeprom or configuration select bit 1 = access configuration registers 0 = access flash program or data eeprom memory bit 5 unimplemented: read as 0 bit 4 free: flash row erase enable bit 1 = erase the program memory row addressed by tblptr on the next wr command (cleared by completion of erase operation) 0 = perform write-only bit 3 wrerr: flash program/data eeprom error flag bit ( 1 ) 1 = a write operation is prematurely terminated (any reset during self-timed programming in normal operation or an improper write attempt) 0 = the write operation has completed bit 2 wren: flash program/data eeprom write enable bit 1 = allows write cycles to flash program/data eeprom 0 = inhibits write cycles to flash program/data eeprom bit 1 wr: write control bit 1 = initiates a data eeprom erase/write cycle, or a program memory erase cycle or write cycle (the operation is self-timed and the bit is cleared by hardware once the write is complete. the wr bit can only be set (not cleared) in software.) 0 = write cycle to the eeprom is complete bit 0 rd: read control bit 1 = initiates an eeprom read (read takes one cycle. rd is cleared in hardware. the rd bit can only be set (not cleared) in software. the rd bit cannot be set when eepgd = 1 or cfgs = 1 .) 0 = does not initiate an eeprom read note 1: when a wrerr occurs, the eepgd and cfgs bits are not cleared. this allows tracing of the error condition. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 135 pic18f87k22 family 9.3 reading the data eeprom memory to read a data memory location, the user must write the address to the eeadrh:eeadr register pair, clear the eepgd control bit (eecon1<7>) and then set control bit, rd (eecon1<0>). the data is available in the eedata register after one cycle; therefore, it can be read after one nop instruction. eedata will hold this value until another read operation or until it is written to by the user (during a write operation). the basic process is shown in example 9-1 . 9.4 writing to the data eeprom memory to write an eeprom data location, the address must first be written to the eeadrh:eeadr register pair and the data written to the eedata register. the sequence in example 9-2 must be followed to initiate the write cycle. the write will not begin if this sequence is not exactly followed (write 0x55 to eecon2, write 0xaa to eecon2, then set wr bit) for each byte. it is strongly recommended that interrupts be disabled during this code segment. additionally, the wren bit in eecon1 must be set to enable writes. this mechanism prevents accidental writes to data eeprom due to unexpected code exe- cution (i.e., runaway programs). the wren bit should be kept clear at all times, except when updating the eeprom. the wren bit is not cleared by hardware. after a write sequence has been initiated, eecon1, eeadrh:eeadr and eedata cannot be modified. the wr bit will be inhibited from being set unless the wren bit is set. the wren bit must be set on a previous instruction. both wr and wren cannot be set with the same instruction. at the completion of the write cycle, the wr bit is cleared in hardware and the eeprom interrupt flag bit (eeif) is set. the user may either enable this interrupt, or poll this bit. eeif must be cleared by software. 9.5 write verify depending on the application, good programming practice may dictate that the value written to the memory should be verified against the original value. this should be used in applications where excessive writes can stress bits near the specification limit. note: self-write execution to flash and eeprom memory cannot be done while running in lp oscillator mode (low-power mode). therefore, executing a self-write will put the device into high-power mode. downloaded from: http:///
pic18f87k22 family ds39960d-page 136 ? 2009-2011 microchip technology inc. example 9-1: data eeprom read example 9-2: data eeprom write movlw data_ee_addrh ; movwf eeadrh ; upper bits of data memory address to read movlw data_ee_addr ; movwf eeadr ; lower bits of data memory address to read bcf eecon1, eepgd ; point to data memory bcf eecon1, cfgs ; access eeprom bsf eecon1, rd ; eeprom read nop movf eedata, w ; w = eedata movlw data_ee_addrh ; movwf eeadrh ; upper bits of data memory address to write movlw data_ee_addr ; movwf eeadr ; lower bits of data memory address to write movlw data_ee_data ; movwf eedata ; data memory value to write bcf eecon1, eepgd ; point to data memory bcf eecon1, cfgs ; access eeprom bsf eecon1, wren ; enable writes bcf intcon, gie ; disable interrupts movlw 0x55 ; required movwf eecon2 ; write 55h sequence movlw 0xaa ; movwf eecon2 ; write 0aah bsf eecon1, wr ; set wr bit to begin write btfsc eecon1, wr ; wait for write to complete goto $-2 bsf intcon, gie ; enable interrupts ; user code execution bcf eecon1, wren ; disable writes on write complete (eeif set) downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 137 pic18f87k22 family 9.6 operation during code-protect data eeprom memory has its own code-protect bits in the configuration words. external read and write operations are disabled if code protection is enabled. the microcontroller itself can both read and write to the internal data eeprom, regardless of the state of the code-protect configuration bit. refer to section 28.0 special features of the cpu for additional information. 9.7 protection against spurious write there are conditions when the device may not want to write to the data eeprom memory. to protect against spurious eeprom writes, various mechanisms have been implemented. on power-up, the wren bit is cleared. in addition, writes to the eeprom are blocked during the power-up timer period (t pwrt , parameter 33 in table 31-13 ). the write initiate sequence, and the wren bit together, help prevent an accidental write during brown-out, power glitch or software malfunction. 9.8 using the data eeprom the data eeprom is a high-endurance, byte address- able array that has been optimized for the storage of frequently changing information (e.g., program variables or other data that is updated often). frequently changing values will typically be updated more often than specification d124 . if this is the case, an array refresh must be performed. for this reason, variables that change infrequently (such as constants, ids, calibration, etc.) should be stored in flash program memory. a simple data eeprom refresh routine is shown in example 9-3 . example 9-3: data eeprom refresh routine note: if data eeprom is only used to store constants and/or data that changes often, an array refresh is likely not required. see specification d124 . clrf eeadr ; start at address 0 clrf eeadrh ; bcf eecon1, cfgs ; set for memory bcf eecon1, eepgd ; set for data eeprom bcf intcon, gie ; disable interrupts bsf eecon1, wren ; enable writes loop ; loop to refresh array bsf eecon1, rd ; read current address movlw 0x55 ; movwf eecon2 ; write 55h movlw 0xaa ; movwf eecon2 ; write 0aah bsf eecon1, wr ; set wr bit to begin write btfsc eecon1, wr ; wait for write to complete bra $-2 incfsz eeadr, f ; increment address bra loop ; not zero, do it again incfsz eeadrh, f ; increment the high address bra loop ; not zero, do it again bcf eecon1, wren ; disable writes bsf intcon, gie ; enable interrupts downloaded from: http:///
pic18f87k22 family ds39960d-page 138 ? 2009-2011 microchip technology inc. table 9-1: registers associated with data eeprom memory name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif eeadrh eeprom address register high byte eeadr eeprom address register low byte eedata eeprom data register eecon2 eeprom control register 2 (not a physical register) eecon1 eepgd cfgs free wrerr wren wr rd ipr6 eeip cmp3ip cmp2ip cmp1ip pir6 eeif cmp3if cmp2if cmp1if pie6 eeie cmp3ie cmp2ie cmp1ie legend: = unimplemented, read as 0 . shaded cells are not used during flash/eeprom access. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 139 pic18f87k22 family 10.0 8 x 8 hardware multiplier 10.1 introduction all pic18 devices include an 8 x 8 hardware multiplier as part of the alu. the multiplier performs an unsigned operation and yields a 16-bit result that is stored in the product register pair, prodh:prodl. the multipliers operation does not affect any flags in the status register. making multiplication a hardware operation allows it to be completed in a single instruction cycle. this has the advantages of higher computational throughput and reduced code size for multiplication algorithms and allows pic18 devices to be used in many applications previously reserved for digital-signal processors. a comparison of various hardware and software multiply operations, along with the savings in memory and execution time, is shown in table 10-1 . 10.2 operation example 10-1 shows the instruction sequence for an 8 x 8 unsigned multiplication. only one instruction is required when one of the arguments is already loaded in the wreg register. example 10-2 shows the sequence to do an 8 x 8 signed multiplication. to account for the sign bits of the arguments, each arguments most significant bit (msb) is tested and the appropriate subtractions are done. example 10-1: 8 x 8 unsigned multiply routine example 10-2: 8 x 8 signed multiply routine table 10-1: performance comparison for various multiply operations movf arg1, w ; mulwf arg2 ; arg1 * arg2 -> ; prodh:prodl movf arg1, w mulwf arg2 ; arg1 * arg2 -> ; prodh:prodl btfsc arg2, sb ; test sign bit subwf prodh, f ; prodh = prodh ; - arg1 movf arg2, w btfsc arg1, sb ; test sign bit subwf prodh, f ; prodh = prodh ; - arg2 routine multiply method program memory (words) cycles (max) time @ 64 mhz @ 48 mhz @ 10 mhz @ 4 mhz 8 x 8 unsigned without hardware multiply 13 69 4.3 ? s5 . 7 ? s2 7 . 6 ? s 69 ? s hardware multiply 1 1 62.5 ns 83.3 ns 400 ns 1 ? s 8 x 8 signed without hardware multiply 33 91 5.6 ? s7 . 5 ? s3 6 . 4 ? s 91 ? s hardware multiply 6 6 375 ns 500 ns 2.4 ? s6 ? s 16 x 16 unsigned without hardware multiply 21 242 15.1 ? s2 0 . 1 ? s9 6 . 8 ? s2 4 2 ? s hardware multiply 28 28 1.7 ? s2 . 3 ? s 11.2 ? s 28 ? s 16 x 16 signed without hardware multiply 52 254 15.8 ? s2 1 . 2 ? s 101.6 ? s254 ? s hardware multiply 35 40 2.5 ? s3 . 3 ? s1 6 . 0 ? s 40 ? s downloaded from: http:///
pic18f87k22 family ds39960d-page 140 ? 2009-2011 microchip technology inc. example 10-3 shows the sequence to do a 16 x 16 unsigned multiplication. equation 10-1 shows the algorithm that is used. the 32-bit result is stored in four registers (res3:res0). equation 10-1: 16 x 16 unsigned multiplication algorithm example 10-3: 16 x 16 unsigned multiply routine example 10-4 shows the sequence to do a 16 x 16 signed multiply. equation 10-2 shows the algorithm used. the 32-bit result is stored in four registers (res3:res0). to account for the sign bits of the arguments, the msb for each argument pair is tested and the appropriate subtractions are done. equation 10-2: 16 x 16 signed multiplication algorithm example 10-4: 16 x 16 signed multiply routine res3:res0 = arg1h:arg1l ? arg2h:arg2l = (arg1h ? arg2h ? 2 16 ) + (arg1h ? arg2l ? 2 8 ) + (arg1l ? arg2h ? 2 8 ) + (arg1l ? arg2l) movf arg1l, w mulwf arg2l ; arg1l * arg2l-> ; prodh:prodl movff prodh, res1 ; movff prodl, res0 ; ; movf arg1h, w mulwf arg2h ; arg1h * arg2h-> ; prodh:prodl movff prodh, res3 ; movff prodl, res2 ; ; movf arg1l, w mulwf arg2h ; arg1l * arg2h-> ; prodh:prodl movf prodl, w ; addwf res1, f ; add cross movf prodh, w ; products addwfc res2, f ; clrf wreg ; addwfc res3, f ; ; movf arg1h, w ; mulwf arg2l ; arg1h * arg2l-> ; prodh:prodl movf prodl, w ; addwf res1, f ; add cross movf prodh, w ; products addwfc res2, f ; clrf wreg ; addwfc res3, f ; res3:res0= arg1h:arg1l ? arg2h:arg2l = (arg1h ? arg2h ? 2 16 ) + (arg1h ? arg2l ? 2 8 ) + (arg1l ? arg2h ? 2 8 ) + (arg1l ? arg2l) + (-1 ? arg2h<7> ? arg1h:arg1l ? 2 16 ) + (-1 ? arg1h<7> ? arg2h:arg2l ? 2 16 ) movf arg1l, w mulwf arg2l ; arg1l * arg2l -> ; prodh:prodl movff prodh, res1 ; movff prodl, res0 ; ; movf arg1h, w mulwf arg2h ; arg1h * arg2h -> ; prodh:prodl movff prodh, res3 ; movff prodl, res2 ; ; movf arg1l, w mulwf arg2h ; arg1l * arg2h -> ; prodh:prodl movf prodl, w ; addwf res1, f ; add cross movf prodh, w ; products addwfc res2, f ; clrf wreg ; addwfc res3, f ; ; movf arg1h, w ; mulwf arg2l ; arg1h * arg2l -> ; prodh:prodl movf prodl, w ; addwf res1, f ; add cross movf prodh, w ; products addwfc res2, f ; clrf wreg ; addwfc res3, f ; ; btfss arg2h, 7 ; arg2h:arg2l neg? bra sign_arg1 ; no, check arg1 movf arg1l, w ; subwf res2 ; movf arg1h, w ; subwfb res3 ; sign_arg1 btfss arg1h, 7 ; arg1h:arg1l neg? bra cont_code ; no, done movf arg2l, w ; subwf res2 ; movf arg2h, w ; subwfb res3 ; cont_code : downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 141 pic18f87k22 family 11.0 interrupts members of the pic18f87k22 family of devices have multiple interrupt sources and an interrupt priority feature that allows most interrupt sources to be assigned a high-priority level or a low-priority level. the high-priority interrupt vector is at 0008h and the low-priority interrupt vector is at 0018h. high-priority interrupt events will interrupt any low-priority interrupts that may be in progress. the registers for controlling interrupt operation are: rcon intcon intcon2 intcon3 pir1, pir2, pir3 pie1, pie2, pie3 ipr1, ipr2, ipr3 it is recommended that the microchip header files supplied with mplab ? ide be used for the symbolic bit names in these registers. this allows the assembler/compiler to automatically take care of the placement of these bits within the specified register. in general, interrupt sources have three bits to control their operation. they are: flag bit C indicating that an interrupt event occurred enable bit C enabling program execution to branch to the interrupt vector address when the flag bit is set priority bit C specifying high priority or low priority the interrupt priority feature is enabled by setting the ipen bit (rcon<7>). when interrupt priority is enabled, there are two bits that enable interrupts globally. setting the gieh bit (intcon<7>) enables all interrupts that have the priority bit set (high priority). setting the giel bit (intcon<6>) and gieh bit (intcon<7>) enables all interrupts that have the priority bit cleared (low priority). when the interrupt flag, enable bit and appropriate global interrupt enable bit are set, the interrupt will vector immediately to address, 0008h or 0018h, depending on the priority bit setting. individual interrupts can be disabled through their corresponding enable bits. when the ipen bit is cleared (default state), the interrupt priority feature is disabled and interrupts are compatible with pic ? mid-range devices. in compatibility mode, the interrupt priority bits for each source have no effect. intcon<6> is the peie bit that enables/disables all peripheral interrupt sources. intcon<7> is the gie bit that enables/disables all interrupt sources. all interrupts branch to address, 0008h, in compatibility mode. when an interrupt is responded to, the global interrupt enable bit is cleared to disable further interrupts. if the ipen bit is cleared, this is the gie bit. if interrupt priority levels are used, this will be either the gieh or giel bit. high-priority interrupt sources can interrupt a low-priority interrupt. low-priority interrupts are not processed while high-priority interrupts are in progress. the return address is pushed onto the stack and the pc is loaded with the interrupt vector address (0008h or 0018h). once in the interrupt service routine (isr), the source(s) of the interrupt can be determined by poll- ing the interrupt flag bits. the interrupt flag bits must be cleared in software, before re-enabling interrupts, to avoid recursive interrupts. the return from interrupt instruction, retfie , exits the interrupt routine and sets the gie bit (gieh or giel if priority levels are used) that re-enables interrupts. for external interrupt events, such as the intx pins or the portb input change interrupt, the interrupt latency will be three to four instruction cycles. the exact latency is the same for one or two-cycle instructions. individual interrupt flag bits are set regardless of the status of their corresponding enable bit or the gie bit. note: do not use the movff instruction to modify any of the interrupt control registers while any interrupt is enabled. doing so may cause erratic microcontroller behavior. downloaded from: http:///
pic18f87k22 family ds39960d-page 142 ? 2009-2011 microchip technology inc. figure 11-1: pic18f87k22 family interrupt logic tmr0ie gie/gieh peie/giel wake-up if in interrupt to cpu vector to location 0008h int2if int2ie int2ip int1if int1ie int1ip tmr0if tmr0ie tmr0ip rbif rbie rbip ipen tmr0if tmr0ip int1if int1ie int1ip int2if int2ie int2ip rbif rbie rbip int0if int0ie peie/giel interrupt to cpu vector to location ipen ipen 0018h pir1<7:0> pie1<7:0> ipr1<7:0> high-priority interrupt generation low-priority interrupt generation idle or sleep modes gie/gieh int3if int3ie int3ip int3if int3ie int3ip pir2<7,5:0> pie2<7,5:0> ipr2<7,5:0> pir3<7,5> pie3<7,5> ipr3<7,5> pir1<7:0> pie1<7:0> ipr1<7:0> pir2<7, 5:0> pie2<7, 5:0> ipr2< 7, 5:0 > pir3<7, 5:0> pie3<7, 5:0> ipr3< 7, 5:0 > ipen pir4<7:0> pie4<7:0> ipr4<7:0> pir5<7:0> pie5<7:0> ipr5<7:0> pir6<4, 2:0> pie6<4, 2:0> ipr6<4, 2:0> pir4<7:0> pie4<7:0> ipr4<7:0> pir5<7:0> pie5<7:0> ipr5<7:0> pir6<4, 2:0> pie6<4, 2:0> ipr6<4, 2:0> downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 143 pic18f87k22 family 11.1 intcon registers the intcon registers are readable and writable registers that contain various enable, priority and flag bits. note: interrupt flag bits are set when an interrupt condition occurs regardless of the state of its corresponding enable bit or the global interrupt enable bit. user software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. this feature allows for software polling. register 11-1: intcon: in terrupt control register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-x gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif ( 1 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 gie/gieh: global interrupt enable bit when ipen = 0 : 1 = enables all unmasked interrupts 0 = disables all interrupts when ipen = 1 : 1 = enables all high-priority interrupts 0 = disables all interrupts bit 6 peie/giel: peripheral interrupt enable bit when ipen = 0 : 1 = enables all unmasked peripheral interrupts 0 = disables all peripheral interrupts when ipen = 1 : 1 = enables all low-priority peripheral interrupts 0 = disables all low-priority peripheral interrupts bit 5 tmr0ie: tmr0 overflow interrupt enable bit 1 = enables the tmr0 overflow interrupt 0 = disables the tmr0 overflow interrupt bit 4 int0ie: int0 external interrupt enable bit 1 = enables the int0 external interrupt 0 = disables the int0 external interrupt bit 3 rbie: rb port change interrupt enable bit 1 = enables the rb port change interrupt 0 = disables the rb port change interrupt bit 2 tmr0if: tmr0 overflow interrupt flag bit 1 = tmr0 register has overflowed (must be cleared in software) 0 = tmr0 register did not overflow bit 1 int0if: int0 external interrupt flag bit 1 = the int0 external interrupt occurred (must be cleared in software) 0 = the int0 external interrupt did not occur bit 0 rbif: rb port change interrupt flag bit ( 1 ) 1 = at least one of the rb<7:4> pins changed state (must be cleared in software) 0 = none of the rb<7:4> pins have changed state note 1: a mismatch condition will continue to set this bit. reading portb, and then waiting on e additional instruction cycle, will end the mismatch condition and allow the bit to be cleared. downloaded from: http:///
pic18f87k22 family ds39960d-page 144 ? 2009-2011 microchip technology inc. register 11-2: intcon2: in terrupt control register 2 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 rbpu intedg0 intedg1 intedg2 intedg3 tmr0ip int3ip rbip bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 rbpu : portb pull-up enable bit 1 = all portb pull-ups are disabled 0 = portb pull-ups are enabled by individual tris register values bit 6 intedg0: external interrupt 0 edge select bit 1 = interrupt on rising edge 0 = interrupt on falling edge bit 5 intedg1: external interrupt 1 edge select bit 1 = interrupt on rising edge 0 = interrupt on falling edge bit 4 intedg2: external interrupt 2 edge select bit 1 = interrupt on rising edge 0 = interrupt on falling edge bit 3 intedg3: external interrupt 3 edge select bit 1 = interrupt on rising edge 0 = interrupt on falling edge bit 2 tmr0ip: tmr0 overflow interrupt priority bit 1 =high priority 0 = low priority bit 1 int3ip: int3 external interrupt priority bit 1 =high priority 0 = low priority bit 0 rbip: rb port change interrupt priority bit 1 =high priority 0 = low priority note: interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its correspondi ng enable bit or the global interrupt enable bit. user software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. this feature allows for software polling. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 145 pic18f87k22 family register 11-3: intcon3: interrupt control register 3 r/w-1 r/w-1 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 int2ip int1ip int3ie int2ie int1ie int3if int2if int1if bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 int2ip: int2 external interrupt priority bit 1 =high priority 0 = low priority bit 6 int1ip: int1 external interrupt priority bit 1 =high priority 0 = low priority bit 5 int3ie: int3 external interrupt enable bit 1 = enables the int3 external interrupt 0 = disables the int3 external interrupt bit 4 int2ie: int2 external interrupt enable bit 1 = enables the int2 external interrupt 0 = disables the int2 external interrupt bit 3 int1ie: int1 external interrupt enable bit 1 = enables the int1 external interrupt 0 = disables the int1 external interrupt bit 2 int3if: int3 external interrupt flag bit 1 = the int3 external interrupt occurred (must be cleared in software) 0 = the int3 external interrupt did not occur bit 1 int2if: int2 external interrupt flag bit 1 = the int2 external interrupt occurred (must be cleared in software) 0 = the int2 external interrupt did not occur bit 0 int1if: int1 external interrupt flag bit 1 = the int1 external interrupt occurred (must be cleared in software) 0 = the int1 external interrupt did not occur note: interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its correspondi ng enable bit or the global interrupt enable bit. user software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. this feature allows for software polling. downloaded from: http:///
pic18f87k22 family ds39960d-page 146 ? 2009-2011 microchip technology inc. 11.2 pir registers the pir registers contain the individual flag bits for the peripheral interrupts. due to the number of peripheral interrupt sources, there are six peripheral interrupt request (flag) registers (pir1 through pir6). note 1: interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global interrupt enable bit, gie (intcon<7>). 2: user software should ensure the appropriate interrupt flag bits are cleared prior to enabling an interrupt and after servicing that interrupt. register 11-4: pir1: peripheral interrupt request (flag) register 1 r/w-0 r/w-0 r-0 r-0 r/w-0 r/w-0 r/w-0 r/w-0 pspif adif rc1if tx1if ssp1if tmr1gif tmr2if tmr1if bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 pspif: parallel slave port read/write interrupt flag bit 1 = a read or write operation has taken place (must be cleared in software) 0 = no read or write operation has occurred bit 6 adif: a/d converter interrupt flag bit 1 = an a/d conversion completed (must be cleared in software) 0 = the a/d conversion is not complete bit 5 rc1if: eusart receive interrupt flag bit 1 = the eusart receive buffer, rcreg1, is full (cleared when rcreg1 is read) 0 = the eusart receive buffer is empty bit 4 tx1if: eusart transmit interrupt flag bit 1 = the eusart transmit buffer, txreg1, is empty (cleared when txreg1 is written) 0 = the eusart transmit buffer is full bit 3 ssp1if: master synchronous serial port interrupt flag bit 1 = the transmission/reception is complete (must be cleared in software) 0 = waiting to transmit/receive bit 2 tmr1gif: timer1 gate interrupt flag bit 1 = timer gate interrupt occurred (must be cleared in software) 0 = no timer gate interrupt occurred bit 1 tmr2if: tmr2 to pr2 match interrupt flag bit 1 = tmr2 to pr2 match occurred (must be cleared in software) 0 = no tmr2 to pr2 match occurred bit 0 tmr1if: tmr1 overflow interrupt flag bit 1 = tmr1 register overflowed (must be cleared in software) 0 = tmr1 register did not overflow downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 147 pic18f87k22 family register 11-5: pir2: peripheral interrupt request (flag) register 2 r/w-0 u-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 oscfif ssp2if bcl2if bcl1if hlvdif tmr3if tmr3gif bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 oscfif: oscillator fail interrupt flag bit 1 = device oscillator failed, clock input has changed to intosc (must be cleared in software) 0 = device clock is operating bit 6 unimplemented: read as 0 bit 5 ssp2if: master synchronous serial port interrupt flag bit 1 = the transmission/reception has been completed (must be cleared in software) 0 = waiting to transmit/receive bit 4 bcl2if: bus collision interrupt flag bit 1 = a bus collision occurred (must be cleared in software) 0 = no bus collision occurred bit 3 bcl1if: bus collision interrupt flag bit 1 = a bus collision occurred (must be cleared in software) 0 = no bus collision occurred bit 2 hlvdif: high/low-voltage detect interrupt flag bit 1 = a low-voltage condition occurred (must be cleared in software) 0 = the device voltage is above the regulators low-voltage trip point bit 1 tmr3if: tmr3 overflow interrupt flag bit 1 = tmr3 register overflowed (must be cleared in software) 0 = tmr3 register did not overflow bit 0 tmr3gif: tmr3 gate interrupt flag bit 1 = timer gate interrupt occurred (must be cleared in software) 0 = no timer gate interrupt occurred downloaded from: http:///
pic18f87k22 family ds39960d-page 148 ? 2009-2011 microchip technology inc. register 11-6: pir3: peripheral interrupt request (flag) register 3 r/w-0 u-0 r-0 r-0 r/w-0 r/w-0 r/w-0 r/w-0 tmr5gif rc2if tx2if ctmuif ccp2if ccp1if rtccif bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 tmr5gif: timer5 gate interrupt flag bit 1 = timer gate interrupt occurred (must be cleared in software) 0 = no timer gate interrupt occurred bit 6 unimplemented: read as 0 bit 5 rc2if: eusart receive interrupt flag bit 1 = the eusart receive buffer, rcreg2, is full (cleared when rcreg2 is read) 0 = the eusart receive buffer is empty bit 4 tx2if: eusart transmit interrupt flag bit 1 = the eusart transmit buffer, txreg2, is empty (cleared when txreg2 is written) 0 = the eusart transmit buffer is full bit 3 ctmuif: ctmu interrupt flag bit 1 = ctmu interrupt occurred (must be cleared in software) 0 = no ctmu interrupt occurred bit 2 ccp2if: eccp2 interrupt flag bit capture mode: 1 = a tmr register capture occurred (must be cleared in software) 0 = no tmr register capture occurred compare mode: 1 = a tmr register compare match occurred (must be cleared in software) 0 = no tmr register compare match occurred pwm mode: unused in this mode. bit 1 ccp1if: eccp1 interrupt flag bit capture mode: 1 = a tmr register capture occurred (must be cleared in software) 0 = no tmr register capture occurred compare mode: 1 = a tmr register compare match occurred (must be cleared in software) 0 = no tmr register compare match occurred pwm mode: unused in this mode. bit 0 rtccif: rtcc interrupt flag bit 1 = rtcc interrupt occurred (must be cleared in software) 0 = no rtcc interrupt occurred downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 149 pic18f87k22 family register 11-7: pir4: peripheral interrupt request (flag) register 4 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 ccp10if ( 1 ) ccp9if ( 1 ) ccp8if ccp7if ccp6if ccp5if ccp4if ccp3if bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-1 ccp<10:4>if: ccp<10:4> interrupt flag bits ( 1 ) capture mode : 1 = a tmr register capture occurred (must be cleared in software) 0 = no tmr register capture occurred compare mode : 1 = a tmr register compare match occurred (must be cleared in software) 0 = no tmr register compare match occurred pwm mode : not used in pwm mode. bit 0 ccp3if: eccp3 interrupt flag bit capture mode : 1 = a tmr register capture occurred (must be cleared in software) 0 = no tmr register capture occurred compare mode : 1 = a tmr register compare match occurred (must be cleared in software) 0 = no tmr register compare match occurred pwm mode : not used in pwm mode. note 1: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
pic18f87k22 family ds39960d-page 150 ? 2009-2011 microchip technology inc. register 11-8: pir5: peripheral interrupt request (flag) register 5 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 tmr7gif ( 1 ) tmr12if ( 1 ) tmr10if ( 1 ) tmr8if tmr7if ( 1 ) tmr6if tmr5if tmr4if bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 tmr7gif: tmr7 gate interrupt flag bits ( 1 ) 1 = tmr gate interrupt occurred (bit must be cleared in software) 0 = no tmr gate interrupt occurred bit 6 tmr12if: tmr12 to pr12 match interrupt flag bit ( 1 ) 1 = tmr12 to pr12 match occurred (must be cleared in software) 0 = no tmr12 to pr12 match occurred bit 5 tmr10if: tmr10 to pr10 match interrupt flag bit ( 1 ) 1 = tmr10 to pr10 match occurred (must be cleared in software) 0 = no tmr10 to pr10 match occurred bit 4 tmr8if: tmr8 to pr8 match interrupt flag bit 1 = tmr8 to pr8 match occurred (must be cleared in software) 0 = no tmr8 to pr8 match occurred bit 3 tmr7if: tmr7 overflow interrupt flag bit ( 1 ) 1 = tmr7 register overflowed (must be cleared in software) 0 = tmr7 register did not overflow bit 2 tmr6if: tmr6 to pr6 match interrupt flag bit 1 = tmr6 to pr6 match occurred (must be cleared in software) 0 = no tmr6 to pr6 match occurred bit 1 tmr5if: tmr5 overflow interrupt flag bit 1 = tmr5 register overflowed (must be cleared in software) 0 = tmr5 register did not overflow bit 0 tmr4if: tmr4 to pr4 match interrupt flag bit 1 = tmr4 to pr4 match occurred (must be cleared in software) 0 = no tmr4 to pr4 match occurred note 1: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 151 pic18f87k22 family register 11-9: pir6: peripheral interrupt request (flag) register 6 u-0 u-0 u-0 r/w-0 u-0 r/w-0 r/w-0 r/w-0 eeif cmp3if cmp2if cmp1if bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-5 unimplemented: read as 0 bit 4 eeif: data eedata/flash write operation interrupt flag bit 1 = the write operation is complete (must be cleared in software) 0 = the write operation is not complete or has not been started bit 3 unimplemented: read as 0 bit 2 cmp3if: cmp3 interrupt flag bit 1 = cmp3 interrupt occurred (must be cleared in software) 0 = no cmp3 interrupt occurred bit 1 cmp2if: cmp2 interrupt flag bit 1 = cmp2 interrupt occurred (must be cleared in software) 0 = no cmp2 interrupt occurred bit 0 cmp1if: cm1 interrupt flag bit 1 = cmp1 interrupt occurred (must be cleared in software) 0 = no cmp1 interrupt occurred downloaded from: http:///
pic18f87k22 family ds39960d-page 152 ? 2009-2011 microchip technology inc. 11.3 pie registers the pie registers contain the individual enable bits for the peripheral interrupts. due to the number of peripheral interrupt sources, there are six peripheral interrupt enable registers (pie1 through pie6). when ipen (rcon<7>) = 0 , the peie bit must be set to enable any of these peripheral interrupts. register 11-10: pie1: peripheral interrupt enable register 1 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 pspie adie rc1ie tx1ie ssp1ie tmr1gie tmr2ie tmr1ie bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 pspie: parallel slave port read/write interrupt enable bit 1 = enables the psp read/write interrupt 0 = disables the psp read/write interrupt bit 6 adie: a/d converter interrupt enable bit 1 = enables the a/d interrupt 0 = disables the a/d interrupt bit 5 rc1ie: eusart receive interrupt enable bit 1 = enables the eusart receive interrupt 0 = disables the eusart receive interrupt bit 4 tx1ie: eusart transmit interrupt enable bit 1 = enables the eusart transmit interrupt 0 = disables the eusart transmit interrupt bit 3 ssp1ie: master synchronous serial port interrupt enable bit 1 = enables the mssp interrupt 0 = disables the mssp interrupt bit 2 tmr1gie: tmr1 gate interrupt enable bit 1 = enables the gate 0 = disabled the gate bit 1 tmr2ie: tmr2 to pr2 match interrupt enable bit 1 = enables the tmr2 to pr2 match interrupt 0 = disables the tmr2 to pr2 match interrupt bit 0 tmr1ie: tmr1 overflow interrupt enable bit 1 = enables the tmr1 overflow interrupt 0 = disables the tmr1 overflow interrupt downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 153 pic18f87k22 family register 11-11: pie2: peripheral interrupt enable register 2 r/w-0 u-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 oscfie ssp2ie bcl2ie bcl1ie hlvdie tmr3ie tmr3gie bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 oscfie: oscillator fail interrupt enable bit 1 = enabled 0 = disabled bit 6 unimplemented: read as 0 bit 5 ssp2ie: master synchronous serial port 2 interrupt enable bit 1 = enables the mssp interrupt 0 = disables the mssp interrupt bit 4 bcl2ie: bus collision interrupt enable bit 1 = enables the bus collision interrupt 0 = disables the bus collision interrupt bit 3 bcl1ie: bus collision interrupt enable bit 1 = enabled 0 = disabled bit 2 hlvdie: high/low-voltage detect interrupt enable bit 1 = enabled 0 = disabled bit 1 tmr3ie: tmr3 overflow interrupt enable bit 1 = enabled 0 = disabled bit 0 tmr3gie: timer3 gate interrupt enable bit 1 = enabled 0 = disabled downloaded from: http:///
pic18f87k22 family ds39960d-page 154 ? 2009-2011 microchip technology inc. register 11-12: pie3: peripheral interrupt enable register 3 r/w-0 u-0 r-0 r-0 r/w-0 r/w-0 r/w-0 r/w-0 tmr5gie rc2ie tx2ie ctmuie ccp2ie ccp1ie rtccie bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 tmr5gie: timer5 gate interrupt enable bit 1 = enabled 0 = disabled bit 6 unimplemented: read as 0 bit 5 rc2ie: eusart receive interrupt enable bit 1 = enabled 0 = disabled bit 4 tx2ie: eusart transmit interrupt enable bit 1 = enabled 0 = disabled bit 3 ctmuie: ctmu interrupt enable bit 1 = enabled 0 = disabled bit 2 ccp2ie: eccp2 interrupt enable bit 1 = enabled 0 = disabled bit 1 ccp1ie: eccp1 interrupt enable bit 1 = enabled 0 = disabled bit 0 rtccie: rtcc interrupt enable bit 1 = enabled 0 = disabled register 11-13: pie4: peripheral interrupt enable register 4 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 ccp10ie ( 1 ) ccp9ie ( 1 ) ccp8ie ccp7ie ccp6ie ccp5ie ccp4ie ccp3ie bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-0 ccp<10:3>ie: ccp<10:3> interrupt enable bits ( 1 ) 1 = enabled 0 =disabled note 1: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 155 pic18f87k22 family register 11-14: pie5: peripheral interrupt enable register 5 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 tmr7gie ( 1 ) tmr12ie ( 1 ) tmr10ie ( 1 ) tmr8ie tmr7ie ( 1 ) tmr6ie tmr5ie tmr4ie bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 tmr7gie: tmr7 gate interrupt enable bit ( 1 ) 1 = enabled 0 =disabled bit 6 tmr12ie: tmr12 to pr12 match interrupt enable bit ( 1 ) 1 = enables the tmr12 to pr12 match interrupt 0 = disables the tmr12 to pr12 match interrupt bit 5 tmr10ie: tmr10 to pr10 match interrupt enable bit ( 1 ) 1 = enables the tmr10 to pr10 match interrupt 0 = disables the tmr10 to pr10 match interrupt bit 4 tmr8ie: tmr8 to pr8 match interrupt enable bit 1 = enables the tmr8 to pr8 match interrupt 0 = disables the tmr8 to pr8 match interrupt bit 3 tmr7ie: tmr7 overflow interrupt enable bit ( 1 ) 1 = enables the tmr7 overflow interrupt 0 = disables the tmr7 overflow interrupt bit 2 tmr6ie: tmr6 to pr6 match interrupt enable bit 1 = enables the tmr6 to pr6 match interrupt 0 = disables the tmr6 to pr6 match interrupt bit 1 tmr5ie: tmr5 overflow interrupt enable bit 1 = enables the tmr5 overflow interrupt 0 = disables the tmr5 overflow interrupt bit 0 tmr4ie: tmr4 to pr4 match interrupt enable bit 1 = enables the tmr4 to pr4 match interrupt 0 = disables the tmr4 to pr4 match interrupt note 1: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
pic18f87k22 family ds39960d-page 156 ? 2009-2011 microchip technology inc. register 11-15: pie6: peripheral interrupt enable register 6 u-0 u-0 u-0 r/w-0 u-0 r/w-0 r/w-0 r/w-0 eeie cmp3ie cmp2ie cmp1ie bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-5 unimplemented: read as 0 bit 4 eeie: data eedata/flash write operation enable bit 1 = interrupt is enabled 0 = interrupt is disabled bit 3 unimplemented: read as 0 bit 2 cmp3ie: cmp3 enable bit 1 = interrupt is enabled 0 = interrupt is disabled bit 1 cmp2e: cmp2 enable bit 1 = interrupt is enabled 0 = interrupt is disabled bit 0 cmp1ie: cmp1 enable bit 1 = interrupt is enabled 0 = interrupt is disabled downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 157 pic18f87k22 family 11.4 ipr registers the ipr registers contain the individual priority bits for the peripheral interrupts. due to the number of peripheral interrupt sources, there are six peripheral interrupt priority registers (ipr1 through ipr6). using the priority bits requires that the interrupt priority enable (ipen) bit (rcon<7>) be set. register 11-16: ipr1: peripheral interrupt priority register 1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 pspip adip rc1ip tx1ip ssp1ip tmr1gip tmr2ip tmr1ip bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 pspip: parallel slave port read/write interrupt priority bit 1 =high priority 0 = low priority bit 6 adip: a/d converter interrupt priority bit 1 =high priority 0 = low priority bit 5 rc1ip: eusart receive interrupt priority bit 1 =high priority 0 = low priority bit 4 tx1ip: eusart transmit interrupt priority bit 1 =high priority 0 = low priority bit 3 ssp1ip: master synchronous serial port interrupt priority bit 1 =high priority 0 = low priority bit 2 tmr1gip: timer1 gate interrupt priority bit 1 =high priority 0 = low priority bit 1 tmr2ip: tmr2 to pr2 match interrupt priority bit 1 =high priority 0 = low priority bit 0 tmr1ip: tmr1 overflow interrupt priority bit 1 =high priority 0 = low priority downloaded from: http:///
pic18f87k22 family ds39960d-page 158 ? 2009-2011 microchip technology inc. register 11-17: ipr2: peripheral interrupt priority register 2 r/w-1 u-0 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 oscfip ssp2ip bcl2ip bcl1ip hlvdip tmr3ip tmr3gip bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 oscfip: oscillator fail interrupt priority bit 1 =high priority 0 = low priority bit 6 unimplemented: read as 0 bit 5 ssp2ip: master synchronous serial port 2 interrupt priority bit 1 =high priority 0 = low priority bit 4 bcl2ip: bus collision interrupt priority bit (mssp) 1 =high priority 0 = low priority bit 3 bcl1ip: bus collision interrupt priority bit 1 =high priority 0 = low priority bit 2 hlvdip: high/low-voltage detect interrupt priority bit 1 =high priority 0 = low priority bit 1 tmr3ip: tmr3 overflow interrupt priority bit 1 =high priority 0 = low priority bit 0 tmr3gip: tmr3 gate interrupt priority bit 1 =high priority 0 = low priority downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 159 pic18f87k22 family register 11-18: ipr3: peripheral interrupt priority register 3 r/w-1 u-0 r-1 r-1 r/w-1 r/w-1 r/w-1 r/w-1 tmr5gip rc2ip tx2ip ctmuip ccp2ip ccp1ip rtccip bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 tmr5gip: timer5 gate interrupt priority bit 1 =high priority 0 = low priority bit 6 unimplemented: read as 0 bit 5 rc2ip: eusart receive priority flag bit 1 =high priority 0 = low priority bit 4 tx2ip: eusart transmit interrupt priority bit 1 =high priority 0 = low priority bit 3 ctmuip: ctmu interrupt priority bit 1 =high priority 0 = low priority bit 2 ccp2ip: eccp2 interrupt priority bit 1 =high priority 0 = low priority bit 1 ccp1ip: eccp1 interrupt priority bit 1 =high priority 0 = low priority bit 0 rtccip: rtcc interrupt priority bit 1 =high priority 0 = low priority register 11-19: ipr4: peripheral interrupt priority register 4 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 ccp10ip ( 1 ) ccp9ip ( 1 ) ccp8ip ccp7ip ccp6ip ccp5ip ccp4ip ccp3ip bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-0 ccp<10:3>ip: ccp<10:3> interrupt priority bits ( 1 ) 1 = high priority 0 = low priority note 1: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
pic18f87k22 family ds39960d-page 160 ? 2009-2011 microchip technology inc. register 11-20: ipr5: peripheral interrupt priority register 5 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 tmr7gip ( 1 ) tmr12ip ( 1 ) tmr10ip ( 1 ) tmr8ip tmr7ip ( 1 ) tmr6ip tmr5ip tmr4ip bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 tmr7gip: tmr7 gate interrupt priority bit ( 1 ) 1 = high priority 0 = low priority bit 6 tmr12ip: tmr12 to pr12 match interrupt priority bit ( 1 ) 1 = high priority 0 = low priority bit 5 tmr10ip: tmr10 to pr10 match interrupt priority bit ( 1 ) 1 = high priority 0 = low priority bit 4 tmr8ip: tmr8 to pr8 match interrupt priority bit 1 = high priority 0 = low priority bit 3 tmr7ip: tmr7 overflow interrupt priority bit ( 1 ) 1 = high priority 0 = low priority bit 2 tmr6ip: tmr6 to pr6 match interrupt priority bit 1 = high priority 0 = low priority bit 1 tmr5ip: tmr5 overflow interrupt priority bit 1 = high priority 0 = low priority bit 0 tmr4ip: tmr4 to pr4 match interrupt priority bit 1 = high priority 0 = low priority note 1: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 161 pic18f87k22 family register 11-21: ipr6: peripheral interrupt priority register 6 u-0 u-0 u-0 r/w-1 u-0 r/w-1 r/w-1 r/w-1 eeip cmp3ip cmp2ip cmp1ip bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-5 unimplemented: read as 0 bit 4 eeip: ee interrupt priority bit 1 =high priority 0 = low priority bit 3 unimplemented: read as 0 bit 2 cmp3ip: cmp3 interrupt priority bit 1 =high priority 0 = low priority bit 1 cmp2ip: cmp2 interrupt priority bit 1 =high priority 0 = low priority bit 0 cmp1ip: cmp1 interrupt priority bit 1 =high priority 0 = low priority downloaded from: http:///
pic18f87k22 family ds39960d-page 162 ? 2009-2011 microchip technology inc. 11.5 rcon register the rcon register contains the bits used to determine the cause of the last reset, or wake-up from idle or sleep modes. rcon also contains the bit that enables interrupt priorities (ipen). register 11-22: rcon: reset control register r/w-0 r/w-1 r/w-1 r/w-1 r-1 r-1 r/w-0 r/w-0 ipen sboren cm ri to pd por bor bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 ipen: interrupt priority enable bit 1 = enable priority levels on interrupts 0 = disable priority levels on interrupts (pic16cxxx compatibility mode) bit 6 sboren: software bor enable bit for details of bit operation, see register 5-1 . bit 5 cm : configuration mismatch flag bit 1 = a configuration mismatch reset has not occurred 0 = a configuration mismatch reset has occurred (must be subsequently set in software) bit 4 ri : reset instruction flag bit for details of bit operation, see register 5-1 . bit 3 to : watchdog timer time-out flag bit for details of bit operation, see register 5-1 . bit 2 pd : power-down detection flag bit for details of bit operation, see register 5-1 . bit 1 por : power-on reset status bit for details of bit operation, see register 5-1 . bit 0 bor : brown-out reset status bit for details of bit operation, see register 5-1 . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 163 pic18f87k22 family 11.6 intx pin interrupts external interrupts on the rb0/int0, rb1/int1, rb2/int2 and rb3/int3 pins are edge-triggered. if the corresponding intedgx bit in the intcon2 register is set (= 1 ), the interrupt is triggered by a rising edge. if that bit is clear, the trigger is on the falling edge. when a valid edge appears on the rbx/intx pin, the corresponding flag bit, intxif, is set. this interrupt can be disabled by clearing the corresponding enable bit, intxie. before re-enabling the interrupt, the flag bit (intxif) must be cleared in software in the interrupt service routine. all external interrupts (int0, int1, int2 and int3) can wake up the processor from the power-managed modes if bit, intxie, was set prior to going into the power-managed modes. if the global interrupt enable bit (gie) is set, the processor will branch to the interrupt vector following wake-up. the interrupt priority for int1, int2 and int3 is determined by the value contained in the interrupt priority bits, int1ip (intcon3<6>), int2ip (intcon3<7>) and int3ip (intcon2<1>). there is no priority bit associated with int0. it is always a high-priority interrupt source. 11.7 tmr0 interrupt in 8-bit mode (the default), an overflow in the tmr0 register (ffh ? 00h) will set flag bit, tmr0if. in 16-bit mode, an overflow in the tmr0h:tmr0l register pair (ffffh ? 0000h) will set tmr0if. the interrupt can be enabled/disabled by setting/clearing enable bit, tmr0ie (intcon<5>). interrupt priority for timer0 is determined by the value contained in the inter- rupt priority bit, tmr0ip (intcon2<2>). for further details on the timer0 module, see section 13.0 timer0 module . 11.8 portb interrupt-on-change an input change on portb<7:4> sets flag bit, rbif (intcon<0>). the interrupt can be enabled/disabled by setting/clearing enable bit, rbie (intcon<3>). interrupt priority for portb interrupt-on-change is determined by the value contained in the interrupt priority bit, rbip (intcon2<0>). 11.9 context saving during interrupts during interrupts, the return pc address is saved on the stack. additionally, the wreg, status and bsr registers are saved on the fast return stack. if a fast return from interrupt is not used (see section 6.3 data memory organization ), the user may need to save the wreg, status and bsr regis- ters on entry to the interrupt service routine (isr). depending on the users application, other registers may also need to be saved. example 11-1 saves and restores the wreg, status and bsr registers during an interrupt service routine. example 11-1: saving status, wreg and bsr registers in ram movwf w_temp ; w_temp is in virtual bank movff status, status_temp ; status_temp located anywhere movff bsr, bsr_temp ; bsr_tmep located anywhere ; ; user isr code ; movff bsr_temp, bsr ; restore bsr movf w_temp, w ; restore wreg movff status_temp, status ; restore status downloaded from: http:///
pic18f87k22 family ds39960d-page 164 ? 2009-2011 microchip technology inc. table 11-1: summary of registers associated with interrupts name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif intcon2 rbpu intedg0 intedg1 intedg2 intedg3 tmr0ip int3ip rbip intcon3 int2ip int1ip int3ie int2ie int1ie int3if int2if int1if pir1 pspip adif rc1if tx1if ssp1if tmr1gif tmr2if tmr1if pir2 oscfif ssp2if bcl2if bcl1if hlvdif tmr3if tmr3gif pir3 tmr5gif rc2if tx2if ctmuif ccp2if ccp1if rtccif pir4 ccp10if ( 1 ) ccp9if ( 1 ) ccp8if ccp7if ccp6if ccp5if ccp4if ccp3if pir5 tmr7gif ( 1 ) tmr12if ( 1 ) tmr10if ( 1 ) tmr8if tmr7if ( 1 ) tmr6if tmr5if tmr4if pir6 eeif cmp3if cmp2if cmp1if pie1 pspie adie rc1ie tx1ie ssp1ie tmr1gie tmr2ie tmr1ie pie2 oscfie ssp2ie bcl2ie bcl1ie hlvdie tmr3ie tmr3gie pie3 tmr5gie rc2ie tx2ie ctmuie ccp2ie ccp1ie rtccie pie4 ccp10ie ( 1 ) ccp9ie ( 1 ) ccp8ie ccp7ie ccp6ie ccp5ie ccp4ie ccp3ie pie5 tmr7gie ( 1 ) tmr12ie ( 1 ) tmr10ie ( 1 ) tmr8ie tmr7ie ( 1 ) tmr6ie tmr5ie tmr4ie pie6 eeie cmp3ie cmp2ie cmp1ie ipr1 pspip adip rc1ip tx1ip ssp1ip tmr1gip tmr2ip tmr1ip ipr2 oscfip ssp2ip bcl2ip bcl1ip hlvdip tmr3ip tmr3gip ipr3 tmr5gip rc2ip tx2ip ctmuip ccp2ip ccp1ip rtccip ipr4 ccp10ip ( 1 ) ccp9ip ( 1 ) ccp8ip ccp7ip ccp6ip ccp5ip ccp4ip ccp3ip ipr5 tmr7gip ( 1 ) tmr12ip ( 1 ) tmr10ip ( 1 ) tmr8ip tmr7ip ( 1 ) tmr6ip tmr5ip tmr4ip ipr6 eeip cmp3ip cmp2ip cmp1ip rcon ipen sboren cm ri to pd por bor legend: shaded cells are not used by the interrupts. note 1: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 165 pic18f87k22 family 12.0 i/o ports depending on the device selected and features enabled, there are up to nine ports available. some pins of the i/o ports are multiplexed with an alternate function from the peripheral features on the device. in general, when a peripheral is enabled, that pin may not be used as a general purpose i/o pin. each port has three memory mapped registers for its operation: tris register (data direction register) port register (reads the levels on the pins of the device) lat register (output latch register) reading the port register reads the current status of the pins, whereas writing to the port register writes to the output latch (lat) register. setting a tris bit (= 1 ) makes the corresponding port pin an input (putting the corresponding output driver in a high-impedance mode). clearing a tris bit (= 0 ) makes the corresponding port pin an output (i.e., puts the contents of the corresponding lat bit on the selected pin). the output latch (lat register) is useful for read-modify-write operations on the value that the i/o pins are driving. read-modify-write operations on the lat register read and write the latched output value for the port register. a simplified model of a generic i/o port, without the interfaces to other peripherals, is shown in figure 12-1 . figure 12-1: generic i/o port operation 12.1 i/o port pin capabilities when developing an application, the capabilities of the port pins must be considered. outputs on some pins have higher output drive strength than others. similarly, some pins can tolerate higher than v dd input levels. all of the digital ports are 5.5v input tolerant. the ana- log ports have the same tolerance C having clamping diodes implemented internally. 12.1.1 pin output drive when used as digital i/o, the output pin drive strengths vary, according to the pins grouping, to meet the needs for a variety of applications. in general, there are two classes of output pins, in terms of drive capability: outputs designed to drive higher current loads, such as leds: - porta - portb -portc outputs with lower drive levels, but capable of driving normal digital circuit loads with a high input impedance. able to drive leds, but only those with smaller current requirements: - portd - porte - portf - portg -porth ( ? ) -portj ( ? ) ? these ports are not available on 64-pin devices. 12.1.2 pull-up configuration four of the i/o ports (portb, portd, porte and portj) implement configurable weak pull-ups on all pins. these are internal pull-ups that allow floating digital input signals to be pulled to a consistent level without the use of external resistors. the pull-ups are enabled with a single bit for each of the ports: rbpu (intcon2<7>) for portb, and rdpu, repu and rjpu (padcfg1<7:5>) for the other ports. data bus wr lat wr tris rd port data latch tris latch rd tris input buffer i/o pin q d ckx q d ckx en qd en rd lat or port downloaded from: http:///
pic18f87k22 family ds39960d-page 166 ? 2009-2011 microchip technology inc. register 12-1: padcfg1: pad configuration register r/w-0 r/w-0 r/w-0 u-0 u-0 r/w-0 r/w-0 u-0 rdpu repu rjpu ( 2 ) rtsecsel1 ( 1 ) rtsecsel0 ( 1 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 rdpu: portd pull-up enable bit 1 = portd pull-up resistors are enabled by individual port latch values 0 = all portd pull-up resistors are disabled bit 6 repu: porte pull-up enable bit 1 = porte pull-up resistors are enabled by individual port latch values 0 = all porte pull-up resistors are disabled bit 5 rjpu: portj pull-up enable bit ( 2 ) 1 = portj pull-up resistors are enabled by individual port latch values 0 = all portj pull-up resistors are disabled bit 4-3 unimplemented: read as 0 bit 2-1 rtsecsel<1:0>: rtcc seconds clock output select bits ( 1 ) 11 = reserved; do not use 10 = rtcc source clock is selected for the rtcc pin (the pin can be lf-intosc or sosc, depending on the rtcosc (config3l<1>) bit setting) 01 = rtcc seconds clock is selected for the rtcc pin 00 = rtcc alarm pulse is selected for the rtcc pin bit 0 unimplemented: read as 0 note 1: to enable the actual rtcc output, the rtcoe (rtccfg<2>) bit must be set. 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 167 pic18f87k22 family 12.1.3 open-drain outputs the output pins for several peripherals are also equipped with a configurable, open-drain output option. this allows the peripherals to communicate with external digital logic, operating at a higher voltage level, without the use of level translators. the open-drain option is implemented on port pins specifically associated with the data and clock outputs of the usarts, the mssp module (in spi mode) and the ccp modules. this option is selectively enabled by setting the open-drain control bits in the registers, odcon1, odcon2 and odcon3. when the open-drain option is required, the output pin must also be tied through an external pull-up resistor provided by the user to a higher voltage level, up to 5v ( figure 12-2 ). when a digital logic high signal is output, it is pulled up to the higher voltage level. figure 12-2: using the open-drain output (usart shown as example) tx x +5v 3.3v (at logic 1 ) 3.3v v dd 5v pic18f87k22 register 12-2: odcon1: peripheral open-drain control register 1 r/w-0 r/w-0 r/w-0 u-0 u-0 u-0 u-0 r/w-0 ssp1od ccp2od ccp1od ssp2od bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 ssp1od: mssp1 open-drain output enable bit 1 = open-drain capability is enabled 0 = open-drain capability is disabled bit 6 ccp2od: eccp2 open-drain output enable bit 1 = open-drain capability is enabled 0 = open-drain capability is disabled bit 5 ccp1od: eccp1 open-drain output enable bit 1 = open-drain capability is enabled 0 = open-drain capability is disabled bit 4-1 unimplemented: read as 0 bit 0 ssp2od: mssp2 open-drain output enable bit 1 = open-drain capability is enabled 0 = open-drain capability is disabled downloaded from: http:///
pic18f87k22 family ds39960d-page 168 ? 2009-2011 microchip technology inc. register 12-3: odcon2: peripheral open-drain control register 2 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 ccp10od ( 1 ) ccp9od ( 1 ) ccp8od ccp7od ccp6od ccp5od ccp4od ccp3od bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 ccp10od: ccp10 open-drain output enable bit ( 1 ) 1 = open-drain capability is enabled 0 = open-drain capability is disabled bit 6 ccp9od: ccp9 open-drain output enable bit ( 1 ) 1 = open-drain capability is enabled 0 = open-drain capability is disabled bit 5 ccp8od: ccp8 open-drain output enable bit 1 = open-drain capability is enabled 0 = open-drain capability is disabled bit 4 ccp7od: ccp7 open-drain output enable bit 1 = open-drain capability is enabled 0 = open-drain capability is disabled bit 3 ccp6od: ccp6 open-drain output enable bit 1 = open-drain capability is enabled 0 = open-drain capability is disabled bit 2 ccp5od: ccp5 open-drain output enable bit 1 = open-drain capability is enabled 0 = open-drain capability is disabled bit 1 ccp4od: ccp4 open-drain output enable bit 1 = open-drain capability is enabled 0 = open-drain capability is disabled bit 0 ccp3od: eccp3 open-drain output enable bit 1 = open-drain capability is enabled 0 = open-drain capability is disabled note 1: not implemented on devices with 32-byte program memory (pic18fx5k22). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 169 pic18f87k22 family 12.1.4 analog and digital ports many of the ports multiplex analog and digital function- ality, providing a lot of flexibility for hardware designers. pic18f87k22 family devices can make any analog pin analog or digital, depending on an applications needs. the ports analog/digital functionality is controlled by registers: ancon0, ancon1 and ancon2. setting these registers makes the corresponding pins analog and clearing the registers makes the ports digi- tal. for details on these registers, see section 23.0 12-bit analog-to-digital converter (a/d) module . register 12-4: odcon3: peripheral open-drain control register 3 r/w-0 r/w-0 u-0 u-0 u-0 u-0 u-0 r/w-0 u2od u1od ctmuds bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 u2od: eusart2 open-drain output enable bit 1 = open-drain capability is enabled 0 = open-drain capability is disabled bit 6 u1od: eusart1 open-drain output enable bit 1 = open-drain capability is enabled 0 = open-drain capability is disabled bit 5-1 unimplemented: read as 0 bit 0 ctmuds: ctmu pulse delay enable bit 1 = pulse delay input for ctmu is enabled on pin, rf1 0 = pulse delay input for ctmu is disabled on pin, rf1 downloaded from: http:///
pic18f87k22 family ds39960d-page 170 ? 2009-2011 microchip technology inc. 12.2 porta, trisa and lata registers porta is an 8-bit wide, bidirectional port. the corre- sponding data direction and output latch registers are trisa and lata. ra4/t0cki is a schmitt trigger input. all other porta pins have ttl input levels and full cmos output drivers. ra5 and ra<3:0> are multiplexed with analog inputs for the a/d converter. the operation of the analog inputs as a/d converter inputs is selected by clearing or setting the ansel control bits in the ancon1 register. the corresponding trisa bits control the direction of these pins, even when they are being used as analog inputs. the user must ensure the bits in the trisa register are maintained set when using them as analog inputs. osc2/clko/ra6 and osc1/clki/ra7 normally serve as the external circuit connections for the exter- nal (primary) oscillator circuit (hs oscillator modes), or the external clock input and output (ec oscillator modes). in these cases, ra6 and ra7 are not available as digital i/o and their corresponding tris and lat bits are read as 0 . when the device is configured to use hf-intosc, mf-intosc or lf-intosc as the default oscillator mode, ra6 and ra7 are automatically configured as digital i/o; the oscillator and clock in/clock out functions are disabled. ra5 has additional functionality for timer1 and timer3. it can be configured as the timer1 clock input or the timer3 external clock gate input. example 12-1: initiali zing porta note: ra5 and ra<3:0> are configured as analog inputs on any reset and are read as 0 . ra4 is configured as a digital input. clrf porta ; initialize porta by ; clearing output latches clrf lata ; alternate method to ; clear output data latches banksel ancon1 ; select bank with ancon1 register movlw 00h ; configure a/d movwf ancon1 ; for digital inputs banksel trisa ; select bank with trisa register movlw 0bfh ; value used to initialize ; data direction movwf trisa ; set ra<7, 5:0> as inputs, ; ra<6> as output downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 171 pic18f87k22 family table 12-1: porta functions table 12-2: summary of regist ers associated with porta pin name function tris setting i/o i/o type description ra0/an0/ulpwu ra0 0 o dig lata<0> data output; not affected by analog input. 1 i ttl porta<0> data input; disabled when analog input is enabled. an0 1 i ana a/d input channel 0. default input configuration on por; does not affect digital output. ulpwu 1 i ana ultra low-power wake-up input. ra1/an1 ra1 0 o dig lata<1> data output; not affected by analog input. 1 i ttl porta<1> data input; disabled when analog input is enabled. an1 1 i ana a/d input channel 1. default input configuration on por; does not affect digital output. ra2/an2/v ref -r a 2 0 o dig lata<2> data output; not affected by analog input. 1 i ttl porta<2> data input; disabled when analog functions are enabled. an2 1 i ana a/d input channel 2. default input configuration on por. v ref - 1 i ana a/d and comparator low reference voltage input. ra3/an3/v ref +r a 3 0 o dig lata<3> data output; not affected by analog input. 1 i ttl porta<3> data input; disabled when analog input is enabled. an3 1 i ana a/d input channel 3. default input configuration on por. v ref + 1 i ana a/d and comparator high reference voltage input. ra4/t0cki ra4 0 o dig lata<4> data output. 1 i st porta<4> data input. default configuration on por. t0cki x i st timer0 clock input. ra5/an4/t1cki/ t3g/hlvdin ra5 0 o dig lata<5> data output; not affected by analog input. 1 i ttl porta<5> data input; disabled when analog input is enabled. an4 1 i ana a/d input channel 4. default configuration on por. t1cki x i st timer1 clock input. t3g x i st timer3 external clock gate input. hlvdin 1 i ana high/low-voltage detect (hlvd) external trip point input. osc2/clko/ra6 osc2 x o ana main oscillator feedback output connection (hs, xt and lp modes). clko x o dig system cycle clock output (f osc /4, ec and intosc modes). ra6 0 o dig lata<6> data output; disabled when fosc2 configuration bit is set. 1 i ttl porta<6> data input; disabled when fosc2 configuration bit is set. osc1/clki/ra7 osc1 x i ana main oscillator input connection (hs, xt and lp modes). clki x i ana main external clock source input (ec modes). ra7 0 o dig lata<7> data output; disabled when fosc2 configuration bit is set. 1 i ttl porta<7> data input; disabled when fosc2 configuration bit is set. legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, ttl = ttl buffer input, x = dont care (tris bit does not affect port direction or is overridden for this option). name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 porta ra7 ( 1 ) ra6 ( 1 ) ra5 ra4 ra3 ra2 ra1 ra0 lata lata7 ( 1 ) lata6 ( 1 ) lata5 lata4 lata3 lata2 lata1 lata0 trisa trisa7 ( 1 ) trisa6 ( 1 ) trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 ancon0 ansel7 ansel6 ansel5 ansel4 ansel3 ansel2 ansel1 ansel0 legend: = unimplemented, read as 0 . shaded cells are not used by porta. note 1: these bits are enabled depending on the oscillator mode selected. when not enabled as porta pins, they are disabled and read as x . downloaded from: http:///
pic18f87k22 family ds39960d-page 172 ? 2009-2011 microchip technology inc. 12.3 portb, trisb and latb registers portb is an eight-bit wide, bidirectional port. the corresponding data direction and output latch registers are trisb and latb. all pins on portb are digital only. example 12-2: initializing portb each of the portb pins has a weak internal pull-up. a single control bit can turn on all the pull-ups. this is performed by clearing bit, rbpu (intcon2<7>). the weak pull-up is automatically turned off when the port pin is configured as an output. the pull-ups are disabled on a power-on reset. four of the portb pins (rb<7:4>) have an interrupt-on-change feature. only pins configured as inputs can cause this interrupt to occur. any rb<7:4> pin configured as an output will be excluded from the interrupt-on-change comparison. comparisons with the input pins (of rb<7:4>) are made with the old value latched on the last read of portb. the mismatch outputs of rb<7:4> are ored together to generate the rb port change interrupt with flag bit, rbif (intcon<0>). this interrupt can wake the device from power-managed modes. to clear the interrupt in the interrupt service routine: a) any read or write of portb (except with the movff (any), portb instruction). this will end the mismatch condition. b) wait one instruction cycle (such as executing a nop instruction). c) clear flag bit, rbif. a mismatch condition will continue to set flag bit, rbif. reading portb will end the mismatch condition and allow flag bit, rbif, to be cleared after one t cy delay. the interrupt-on-change feature is recommended for wake-up on key depression operation and operations where portb is only used for the interrupt-on-change feature. polling of portb is not recommended while using the interrupt-on-change feature. the rb<3:2> pins are multiplexed as ctmu edge inputs. rb5 has an additional function for timer3 and timer1. it can be configured for timer3 clock input or timer1 external clock gate input. clrf portb ; initialize portb by ; clearing output; data latches clrf latb ; alternate method ; to clear output; data latches movlw 0cfh ; value used to ; initialize data ; direction movwf trisb ; set rb<3:0> as inputs ; rb<5:4> as outputs ; rb<7:6> as inputs table 12-3: portb functions pin name function tris setting i/o i/o type description rb0/int0/flt0 rb0 0 o dig latb<0> data output. 1 i ttl portb<0> data input; weak pull-up when rbpu bit is cleared. int0 1 i st external interrupt 0 input. flt0 x i st enhanced pwm fault input for eccpx. rb1/int1 rb1 0 o dig latb<1> data output. 1 i ttl portb<1> data input; weak pull-up when rbpu bit is cleared. int1 1 i st external interrupt 1 input. rb2/int2/cted1 rb2 0 o dig latb<2> data output. 1 i ttl portb<2> data input; weak pull-up when rbpu bit is cleared. int2 1 i st external interrupt 2 input. cted1 x i st ctmu edge 1 input. legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, ttl = ttl buffer input, x = dont care (tris bit does not affect port direction or is overridden for this option). note 1: alternate assignment for eccp2 when the ccp2mx configur ation bit is cleared and in extended microcontroller mode. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 173 pic18f87k22 family table 12-4: summary of regist ers associated with portb rb3/int3/cted2/ eccp2/p2a rb3 0 o dig latb<3> data output. 1 i ttl portb<3> data input; weak pull-up when rbpu bit is cleared. int3 1 i st external interrupt 3 input. cted2 x i st ctmu edge 2 input. eccp2 ( 1 ) 0 o dig eccp2 compare output and eccp2 pwm output. takes priority over port data. 1 i st eccp2 capture input. p2a 0 o dig eccp2 enhanced pwm output, channel a. may be configured for tri-state during enhanced pwm shutdown events. takes priority over port data. rb4/kbi0 rb4 0 o dig latb<4> data output. 1 i ttl portb<4> data input; weak pull-up when rbpu bit is cleared. kbi0 1 i ttl interrupt-on-pin change. rb5/kbi1/t3cki/ t1g rb5 0 o dig latb<5> data output. 1 i ttl portb<5> data input; weak pull-up when rbpu bit is cleared. kbi1 1 i ttl interrupt-on-pin change. t3cki x i st timer3 clock input. t1g x i st timer1 external clock gate input. rb6/kbi2/pgc rb6 0 o dig latb<6> data output. 1 i ttl portb<6> data input; weak pull-up when rbpu bit is cleared. kbi2 1 i ttl interrupt-on-pin change. pgc x i st serial execution (icsp?) clock input for icsp and icd operations. rb7/kbi3/pgd rb7 0 o dig latb<7> data output. 1 i ttl portb<7> data input; weak pull-up when rbpu bit is cleared. kbi3 1 i ttl interrupt-on-pin change. pgd x o dig serial execution data output for icsp and icd operations. x i st serial execution data input for icsp and icd operations. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 portb rb7 rb6 rb5 rb4 rb3 rb2 rb1 rb0 latb latb7 latb6 latb5 latb4 latb3 latb2 latb1 latb0 trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif intcon2 rbpu intedg0 intedg1 intedg2 intedg3 tmr0ip int3ip rbip intcon3 int2ip int1ip int3ie int2ie int1ie int3if int2if int1if odcon1 ssp1od ccp2od ccp1od ssp2od legend: shaded cells are not used by portb. table 12-3: portb functions (continued) pin name function tris setting i/o i/o type description legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, ttl = ttl buffer input, x = dont care (tris bit does not affect port direction or is overridden for this option). note 1: alternate assignment for eccp2 when the ccp2mx configur ation bit is cleared and in extended microcontroller mode. downloaded from: http:///
pic18f87k22 family ds39960d-page 174 ? 2009-2011 microchip technology inc. 12.4 portc, trisc and latc registers portc is an eight-bit wide, bidirectional port. the corresponding data direction and output latch registers are trisc and latc. only portc pins, rc2 through rc7, are digital only pins. portc is multiplexed with eccp, mssp and eusart peripheral functions ( ta b l e 1 2 - 5 ). the pins have schmitt trigger input buffers. the pins for eccp, spi and eusart are also configurable for open-drain out- put whenever these functions are active. open-drain configuration is selected by setting the spiod, ccpxod and u1od control bits in the registers, odcon1 and odcon3. rc1 is normally configured as the default peripheral pin for the eccp2 module. the assignment of eccp2 is controlled by configuration bit, ccp2mx (default state, ccp2mx = 1 ). when enabling peripheral functions, use care in defin- ing tris bits for each portc pin. some peripherals can override the tris bit to make a pin an output or input. consult the corresponding peripheral section for the correct tris bit settings. the contents of the trisc register are affected by peripheral overrides. reading trisc always returns the current contents, even though a peripheral device may be overriding one or more of the pins. example 12-3: init ializing portc note: these pins are configured as digital inputs on any device reset. clrf portc ; initialize portc by ; clearing output ; data latches clrf latc ; alternate method ; to clear output ; data latches movlw 0cfh ; value used to ; initialize data ; direction movwf trisc ; set rc<3:0> as inputs ; rc<5:4> as outputs ; rc<7:6> as inputs table 12-5: portc functions pin name function tris setting i/o i/o type description rc0/sosco/ sclki/ rc0 0 o dig latc<0> data output. 1 i st portc<0> data input. sosco 1 i st sosc oscillator output. sclki 1 i st digital clock input; enabled when sosc oscillator is disabled. rc1/sosci/ eccp2/p2a rc1 0 o dig latc<1> data output. 1 i st portc<1> data input. sosci x i ana sosc oscillator input. eccp2 ( 1 ) 0 o dig eccp2 compare output and eccp2 pwm output; takes priority over port data. 1 i st eccp2 capture input. p2a 0 o dig eccp2 enhanced pwm output, channel a. may be configured for tri-state during enhanced pwm shutdown events; takes priority over port data. rc2/eccp1/ p1a rc2 0 o dig latc<2> data output. 1 i st portc<2> data input. eccp1 0 o dig eccp1 compare output and eccp1 pwm output; takes priority over port data. 1 i st eccp1 capture input. p1a 0 o dig eccp1 enhanced pwm output, channel a. may be configured for tri-state during enhanced pwm shutdown events; takes priority over port data. legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, ttl = ttl buffe r input, i 2 c = i 2 c?/smbus buffer input, x = dont care (tris bit does not affect port direction or is overridden for this option). note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 175 pic18f87k22 family table 12-6: summary of register s associated with portc rc3/sck1/ scl1 rc3 0 o dig latc<3> data output. 1 i st portc<3> data input. sck1 0 o dig spi clock output (mssp module); takes priority over port data. 1 i st spi clock input (mssp module). scl1 0 odigi 2 c clock output (mssp module); takes priority over port data. 1 ii 2 ci 2 c clock input (mssp module); input type depends on module setting. rc4/sdi1/ sda1 rc4 0 o dig latc<4> data output. 1 i st portc<4> data input. sdi1 i st spi data input (mssp module). sda1 1 odigi 2 c data output (mssp module); takes priority over port data. 1 ii 2 ci 2 c data input (mssp module); input type depends on module setting. rc5/sdo1 rc5 0 o dig latc<5> data output. 1 i st portc<5> data input. sdo1 0 o dig spi data output (mssp module). rc6/tx1/ck1 rc6 0 o dig latc<6> data output. 1 i st portc<6> data input. tx1 1 o dig synchronous serial data output (eusart module); takes priority over port data. ck1 1 o dig synchronous serial data input (eusart module); user must configure as an input. 1 i st synchronous serial clock input (eusart module). rc7/rx1/dt1 rc7 0 o dig latc<7> data output. 1 i st portc<7> data input. rx1 1 i st asynchronous serial receive data input (eusart module). dt1 1 o dig synchronous serial data output (eusart module); takes priority over port data. 1 i st synchronous serial data input (eusart m odule); user must configure as an input. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 portc rc7 rc6 rc5 rc4 rc3 rc2 rc1 rc0 latc latc7 latbc6 latc5 latcb4 latc3 latc2 latc1 latc0 trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 odcon1 ssp1od ccp2od ccp1od ssp2od odcon3 u2od u1od ctmuds legend: shaded cells are not used by portc. table 12-5: portc functions (continued) pin name function tris setting i/o i/o type description legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, ttl = ttl buffe r input, i 2 c = i 2 c?/smbus buffer input, x = dont care (tris bit does not affect port direction or is overridden for this option). note 1: default assignment for eccp2 when the ccp2mx configuration bit is set. downloaded from: http:///
pic18f87k22 family ds39960d-page 176 ? 2009-2011 microchip technology inc. 12.5 portd, trisd and latd registers portd is an 8-bit wide, bidirectional port. the corresponding data direction and output latch registers are trisd and latd. all pins on portd are implemented with schmitt trigger input buffers. each pin is individually configurable as an input or output. each of the portd pins has a weak internal pull-up. a single control bit can turn off all the pull-ups. this is performed by setting bit, rdpu (padcfg1<7>). the weak pull-up is automatically turned off when the port pin is configured as an output. the pull-ups are disabled on all device resets. on 80-pin devices, portd is multiplexed with the system bus as part of the external memory interface. the i/o port and other functions are only available when the interface is disabled by setting the ebdis bit (memcon<7>). when the interface is enabled, portd is the low-order byte of the multiplexed address/data bus (ad<7:0>). the trisd bits are also overridden. portd can also be configured as an 8-bit wide micro- processor port (parallel slave port) by setting control bit, pspmode (trise<4>). in this mode, the input buffers are ttl. for additional information, see section 12.11 parallel slave port . the portd also has the i 2 c and spi functionality on rd4, rd5 and rd6. the pins for spi are also configu- rable for open-drain output. open-drain configuration is selected by setting bit, ssp2od (odcon1<0>). rd0 has a ctmu functionality. rd1 has the functional- ity for the timer5 clock input and timer7 external clock gate input. example 12-4: initializing portd note: these pins are configured as digital inputs on any device reset. clrf portd ; initialize portd by ; clearing output ; data latches clrf latd ; alternate method ; to clear output; data latches movlw 0cfh ; value used to ; initialize data ; direction movwf trisd ; set rd<3:0> as inputs ; rd<5:4> as outputs ; rd<7:6> as inputs table 12-7: portd functions pin name function tris setting i/o i/o type description rd0/psp0/ ad0/ctpls rd0 0 o dig latd<0> data output. 1 i st portd<0> data input. psp0 ( 1 ) x i/o ttl parallel slave port data. ad0 ( 2 ) x i/o ttl external memory address/data 0. ctpls x o dig ctmu pulse generator output. rd1/psp1/ ad1/t5cki/ t7g rd1 0 o dig latd<1> data output. 1 i st portd<1> data input. psp1 ( 1 ) x i/o ttl parallel slave port data. ad1 ( 2 ) x i/o ttl external memory address/data 1. t5cki x i st timer5 clock input. t7g x i st timer7 external clock gate input. rd2/psp2/ad2 rd2 0 o dig latd<2> data output. 1 i st portd<2> data input. psp2 ( 1 ) x i/o ttl parallel slave port data. ad2 ( 2 ) x i/o ttl external memory address/data 2. legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, i 2 c = i 2 c?/smbus buffer input, x = dont care (tris bit does not affect port direction or is overridden for this option). note 1: the parallel slave port (psp) is available only in microcontroller mode. 2: this feature is available only on pic18f8xk22 devices. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 177 pic18f87k22 family table 12-8: summary of register s associated with portd rd3/psp3/ad3 rd3 0 o dig latd<3> data output. 1 i st portd<3> data input. psp3 ( 1 ) x i/o ttl parallel slave port data. ad3 ( 2 ) x i/o ttl external memory address/data 3. rd4/psp4/ ad4/sdo2 rd4 0 o dig latd<4> data output. 1 i st portd<4> data input. psp4 ( 1 ) x i/o ttl parallel slave port data. ad4 ( 2 ) x i/o ttl external memory address/data 4. sdo2 0 p dog spi data output (mssp module). rd5/psp5/ ad5/sdi2/ sda2 rd5 0 o dig latd<5> data output. 1 i st portd<5> data input. psp5 ( 1 ) x i/o ttl parallel slave port data. ad5 ( 2 ) x i/o ttl external memory address/data 5. sdi2 1 i st spi data input (mssp module). sda2 0 oi 2 ci 2 c data input (mssp module). input type depends on module setting. rd6/psp6/ ad6/sck2/ scl2 rd6 0 o dig latd<6> data output. 1 i st portd<6> data input. psp6 ( 1 ) x i/o ttl parallel slave port data. ad6 ( 2 ) x i/o ttl external memory address/data 6. sck2 0 o dig spi clock output (mssp module); takes priority over port data. 1 i st spi clock input (mssp module). scl2 0 od i gi 2 c clock output (mssp module); takes priority over port data. 1 ii 2 ci 2 c clock input (mssp module). input type depends on module setting. rd7/psp7/ ad7/ss2 rd7 0 o dig latd<7> data output. 1 i st portd<7> data input. psp7 ( 1 ) x i/o ttl parallel slave port data. ad7 ( 2 ) x i/o ttl external memory address/data 7. ss2 1 i ttl slave select input for mssp module. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 portd rd7 rd6 rd5 rd4 rd3 rd2 rd1 rd0 latd latd7 latd6 latd5 latd4 latd3 latd2 latd1 latd0 trisd trisd7 trisd6 trisd5 trisd4 trisd3 trisd2 trisd1 trisd0 padcfg1 rdpu repu rjpu ( 1 ) rtsecsel1 resecsel0 odcon1 ssp1od ccp2od ccp1od ssp2od legend: shaded cells are not used by portd. note 1: unimplemented on pic18f6xk22 devices, read as 0 . table 12-7: portd functions (continued) pin name function tris setting i/o i/o type description legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, i 2 c = i 2 c?/smbus buffer input, x = dont care (tris bit does not affect port direction or is overridden for this option). note 1: the parallel slave port (psp) is available only in microcontroller mode. 2: this feature is available only on pic18f8xk22 devices. downloaded from: http:///
pic18f87k22 family ds39960d-page 178 ? 2009-2011 microchip technology inc. 12.6 porte, trise and late registers porte is an eight-bit wide, bidirectional port. the corresponding data direction and output latch registers are trise and late. all pins on porte are implemented with schmitt trigger input buffers. each pin is individually configurable as an input or output. the re7 pin is also configurable for open-drain output when eccp2 is active on this pin. open-drain configuration is selected by setting the ccp2od control bit (odcon1<6>) each of the porte pins has a weak internal pull-up. a single control bit can turn off all the pull-ups. this is performed by setting bit, repu (padcfg1<6>). the weak pull-up is automatically turned off when the port pin is configured as an output. the pull-ups are disabled on any device reset. porte is also multiplexed with enhanced pwm outputs, b and c for eccp1 and eccp3, for outputs, b, c and d for eccp2. for all devices, their default assignments are on porte<6:0>. on 80-pin devices, the multiplexing for the outputs of eccp1 and eccp3 is controlled by the eccpmx con- figuration bit. clearing this bit re-assigns the p1b/p1c and p3b/p3c outputs to porth. for devices operating in microcontroller mode, the re7 pin can be configured as the alternate peripheral pin for the eccp2 module and enhanced pwm output 2a. this is done by clearing the ccp2mx configuration bit. porte is also multiplexed with the parallel slave port address lines. re1 and re0 are multiplexed with the control signals, w r and r d . re3 can also be configured as the reference clock output (refo) from the system clock. for further details, see section 3.7 reference clock output . example 12-5: initializing porte note: these pins are configured as digital inputs on any device reset. clrf porte ; initialize porte by ; clearing output; data latches clrf late ; alternate method ; to clear output; data latches movlw 03h ; value used to ; initialize data ; direction movwf trise ; set re<1:0> as inputs ; re<7:2> as outputs table 12-9: porte functions pin name function tris setting i/o i/o type description re0/rd /p2d ad8 re0 0 o dig late<0> data output. 1 i st porte<0> data input. rd x o dig parallel slave port read strobe pin. x i ttl parallel slave port read pin. p2d 0 o eccp2 pwm output d. may be configured for tri-state during enhanced pwm shutdown events. ad8 ( 2 ) x o dig external memory interface, data bit 8 output. x i ttl external memory interface, data bit 8 input. re1/p2c/wr / ad9 re1 0 o dig late<1> data output. 1 i st porte<1> data input. p2c 0 o eccp2 pwm output c. may be configured for tri-state during enhanced pwm shutdown events. wr x o dig parallel slave port write strobe pin. x i ttl parallel slave port write pin. ad9 ( 2 ) x o dig external memory interface, data bit 9 output. x i ttl external memory interface, data bit 9 input. legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, x = dont care (tris bit does not affect port direction or is overridden for this option). note 1: alternate assignment for eccp2 when the ccp2mx confi guration bit is cleared and in microcontroller mode. 2: this feature is only available on pic18f8xkxx devices. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 179 pic18f87k22 family re2/cs /p2b/ ccp10/ad10 re2 0 o dig late<2> data output. 1 i st porte<2> data input. cs x i ttl parallel slave port chip select. p2b 0 o eccp2 pwm output b. may be configured for tri-state during enhanced pwm shutdown events. ccp10 1 i/o st capture 10 input/compare 10 output/pwm10 output. ad10 ( 2 ) x o dig external memory interface, address/data bit 10 output. x i ttl external memory interface, data bit 10 input. re3/p3c/ ccp9/refo/ ad11 re3 0 o dig late<3> data output. 1 i st porte<3> data input. p3c 0 o eccp3 pwm output c. may be configured for tri-state during enhanced pwm shutdown events. ccp9 0 o dig ccp9 compare/pwm output; takes priority over port data. 1 i st ccp9 capture input. refo x o dig reference output clock. ad11 ( 2 ) x o dig external memory interface, address/data bit 11 output. x i ttl external memory interface, data bit 11 input. re4/p3b/ ccp8/ad12 re4 0 o dig late<4> data output. 1 i st porte<4> data input. p3b 0 o eccp3 pwm output b. may be configured for tri-state during enhanced pwm shutdown events. ccp8 0 o dig ccp8 compare/pwm output; takes priority over port data. 1 i st ccp8 capture input. ad12 ( 2 ) x o dig external memory interface, address/data bit 12 output. x i ttl external memory interface, data bit 12 input. re5/p1c/ ccp7/ad13 re5 0 o dig late<5> data output. 1 i st porte<5> data input. p1c 0 o eccp1 pwm output c. may be configured for tri-state during enhanced pwm shutdown events. ccp7 0 o dig ccp7 compare/pwm output; takes priority over port data. 1 i st ccp7 capture input. ad13 ( 2 ) x o dig external memory interface, address/data bit 13 output. x i ttl external memory interface, data bit 13 input. re6/p1b/ ccp6/ad14 re6 0 o dig late<6> data output. 1 i st porte<6> data input. p1b 0 o eccp1 pwm output b. may be configured for tri-state during enhanced pwm shutdown events. ccp6 0 o dig ccp6 compare/pwm output; takes priority over port data. 1 i st ccp9 capture input. ad14 ( 2 ) x o dig external memory interface, address/data bit 14 output. x i ttl external memory interface, data bit 14 input. table 12-9: porte functions (continued) pin name function tris setting i/o i/o type description legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, x = dont care (tris bit does not affect port direction or is overridden for this opt ion). note 1: alternate assignment for eccp2 when the ccp2mx conf iguration bit is cleared and in microcontroller mode. 2: this feature is only available on pic18f8xkxx devices. downloaded from: http:///
pic18f87k22 family ds39960d-page 180 ? 2009-2011 microchip technology inc. table 12-10: summary of registers associated with porte re7/eccp2/ p2a/ad15 re7 0 o dig late<7> data output. 1 i st porte<7> data input. eccp2 ( 1 ) 0 o dig eccp2 compare/pwm output; takes priority over port data. 1 i st eccp2 capture input. p2a 0 o eccp2 pwm output a. may be configured for tri-state during enhanced pwm shutdown event. ad15 ( 2 ) x o dig external memory interface, address/data bit 15 output. x i ttl external memory interface, data bit 15 input. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 porte re7 re6 re5 re4 re3 re2 re1 re0 late late7 late6 late5 late4 late3 late2 late1 late0 trise trise7 trise6 trise5 trise4 trise3 trise2 trise1 trise0 padcfg1 rdpu repu rjpu ( 2 ) rtsecsel1 rtsecsel0 odcon1 ssp1od ccp2od ccp1od ssp2od odcon2 ccp10od ( 1 ) ccp9od ( 1 ) ccp8od ccp7od ccp6od ccp5od ccp4od ccp3od legend: shaded cells are not used by porte. note 1: unimplemented on pic18fx5k22 devices, read as 0 . 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . table 12-9: porte functions (continued) pin name function tris setting i/o i/o type description legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, x = dont care (tris bit does not affect port direction or is overridden for this option). note 1: alternate assignment for eccp2 when the ccp2mx confi guration bit is cleared and in microcontroller mode. 2: this feature is only available on pic18f8xkxx devices. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 181 pic18f87k22 family 12.7 portf, latf and trisf registers portf is a 7-bit wide, bidirectional port. the corresponding data direction and output latch registers are trisf and latf. all pins on portf are implemented with schmitt trigger input buffers. each pin is individually configurable as an input or output. pins, rf1 through rf6, may be used as comparator inputs or outputs by setting the appropriate bits in the cmcon register. to use rf<7:1> as digital inputs, it is also necessary to turn off the comparators. example 12-6: initializing portf note 1: on device resets, pins, rf<7:1>, are configured as analog inputs and are read as 0 . 2: to configure portf as a digital i/o, turn off the comparators and clear ancon1 and ancon2 to digital. clrf portf ; initialize portf by ; clearing output ; data latches clrf latf ; alternate method ; to clear output ; data latches banksel ancon1 ; select bank with ancon1 register movlw 1fh ; make an6, an7 and an5 digital movwf ancon1 ; movlw 0fh ; make an8, an9, an10 and an11 digital movwf ancon ; set portf as digital i/o banksel trisf ; select bank with trisf register movlw 0ceh ; value used to ; initialize data ; direction movwf trisf ; set rf3:rf1 as inputs ; rf5:rf4 as outputs ; rf7:rf6 as inputs table 12-11: portf functions pin name function tris setting i/o i/o type description rf1/an6/c2out/ ctdin rf1 0 o dig latf<1> data output; not affected by analog input. 1 i st portf<1> data input; disabled when analog input is enabled. an6 1 i ana a/d input channel 6. default configuration on por. c2out 0 o dig comparator 2 output; takes priority over port data. ctdin 1 i st ctmu pulse delay input. rf2/an7/c1out rf2 0 o dig latf<2> data output; not affected by analog input. 1 i st portf<2> data input; disabled when analog input is enabled. an7 1 i ana a/d input channel 7. default configuration on por. c1out 0 o dig comparator 1 output; takes priority over port data. rf3/an8/c2inb/ ctmui rf3 0 o dig latf<3> data output; not affected by analog input. 1 i st portf<3> data input; disabled when analog input is enabled. an8 1 i ana a/d input channel 8 and comparator c2+ input. default input configuration on por; not affected by analog output. c2inb 1 i ana comparator 2 input b. ctmui x o ctmu pulse generator charger for the c2inb comparator input. rf4/an9/c2ina rf4 0 o dig latf<4> data output; not affected by analog input. 1 i st portf<4> data input; disabled when analog input is enabled. an9 1 i ana a/d input channel 9 and comparator c2- input. default input configuration on por; does not affect digital output. c2ina 1 i ana comparator 2 input a. rf5/an10/cv ref / c1inb rf5 0 o dig latf<5> data output; not affected by analog input. disabled when cv ref output is enabled. 1 i st portf<5> data input; disabled when analog input is enabled. disabled when cv ref output is enabled. an10 1 i ana a/d input channel 10 and comparator c1+ input. default input configuration on por. cv ref x o ana comparator voltage reference output. enabling this feature disables digital i/o. c1inb 1 i ana comparator 1 input b. legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, ttl = ttl buffer input, x = dont care (tris bit does not affect port direction or is overridden for this option). downloaded from: http:///
pic18f87k22 family ds39960d-page 182 ? 2009-2011 microchip technology inc. table 12-12: summary of registers associated with portf rf6/an11/c1ina rf6 0 o dig latf<6> data output; not affected by analog input. 1 i st portf<6> data input; disabled when analog input is enabled. an11 1 i ana a/d input channel 11 and comparator c1- input. default input configuration on por; does not affect digital output. c1ina 1 i ana comparator 1 input a. rf7/an5/ss1 rf7 0 o dig latf<7> data output; not affected by analog input. 1 i st portf<7> data input; disabled when analog input is enabled. an5 1 i ana a/d input channel 5. default configuration on por. ss1 1 i ttl slave select input for mssp module. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 portf rf7 rf6 rf5 rf4 rf3 rf2 rf1 latf latf7 latf6 latf5 latf4 latf3 latf2 latf1 trisf trisf7 trisf6 trisf5 trisf4 trisf3 trisf2 trisf1 ancon0 ansel7 ansel6 ansel5 ansel4 ansel3 ansel2 ansel1 ansel0 ancon1 ansel15 ansel14 ansel13 ansel12 ansel11 ansel10 ansel9 ansel8 legend: = unimplemented, read as 0 . shaded cells are not used by portf. table 12-11: portf functions (continued) pin name function tris setting i/o i/o type description legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, ttl = ttl buffer input, x = dont care (tris bit does not affect port direction or is overridden for this option). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 183 pic18f87k22 family 12.8 portg, trisg and latg registers portg is a 5-bit wide, bidirectional port. the corresponding data direction and output latch registers are trisg and latg. portg is multiplexed with the ausart and ccp, eccp, analog, comparator, rtcc and timer input functions ( table 12-13 ). when operating as i/o, all portg pins have schmitt trigger input buffers. the open-drain functionality for the ccpx and uart can be configured using odconx. when enabling peripheral functions, care should be taken in defining tris bits for each portg pin. some peripherals override the tris bit to make a pin an output, while other peripherals override the tris bit to make a pin an input. the user should refer to the corresponding peripheral section for the correct tris bit settings. the pin override value is not loaded into the tris register. this allows read-modify-write of the tris register without concern due to peripheral overrides. example 12-7: initializing portg clrf portg ; initialize portg by ; clearing output ; data latches bcf cm1con, con ; disable ; comparator 1 clrf latg ; alternate method ; to clear output ; data latches banksel ancon2 ; select bank with acon2 register movlw 0f0h ; make an16 to an19 ; digital movwf ancon2 banksel trisg ; select bank with trisg register movlw 04h ; value used to ; initialize data ; direction movwf trisg ; set rg1:rg0 as ; outputs ; rg2 as input ; rg4:rg3 as inputs table 12-13: po rtg functions pin name function tris setting i/o i/o type description rg0/eccp3/ p3a rg0 0 o dig latg<0> data output. 1 i st portg<0> data input. eccp3 0 o dig eccp3 compare output and eccp3 pwm output; takes priority over port data. 1 i st eccp3 capture input. p3a 0 o eccp3 pwm output a. may be configured for tri-state during enhanced pwm shutdown events. rg1/tx2/ck2/ an19/c3out rg1 0 o dig latg<1> data output. 1 i st portg<1> data input. tx2 1 o dig synchronous serial data output (eusart module); takes priority over port data. ck2 1 o dig synchronous serial data input (eus art module); user must configure as an input. 1 i st synchronous serial clock input (eusart module). an19 1 i ana a/d input channel 19. default input configuration on por. does not affect digital output. c3out x o dig comparator 3 output. legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, x = dont care (tris bit does not affect port direction or is overridden for this opt ion). downloaded from: http:///
pic18f87k22 family ds39960d-page 184 ? 2009-2011 microchip technology inc. table 12-14: summary of registers associated with portg rg2/rx2/dt2/ an18/c3ina rg2 0 o dig latg<2> data output. 1 i st portg<2> data input. rx2 1 i st asynchronous serial receive data input (eusart module). dt2 1 o dig synchronous serial data output (eusart module); takes priority over port data. 1 i st synchronous serial data input (eus art module); user must configure as an input. an18 1 i ana a/d input channel 18. default input configuration on por; does not affect digital output. c3ina x i ana comparator 3 input a. rg3/ccp4/an17/ p3d/c3inb rg3 0 o dig latg<3> data output. 1 i st portg<3> data input. ccp4 0 o dig ccp4 compare/pwm output; takes priority over port data. 1 i st ccp4 capture input. an17 1 i ana a/d input channel 17. default input configuration on por; does not affect digital output. p3d 0 o eccp3 pwm output d. may be configured for tri-state during enhanced pwm. c3inb x i ana comparator 3 input b. rg4/rtcc/ t7cki/t5g/ ccp5/an16/ p1d/c3inc rg4 0 o dig latg<4> data output. 1 i st portg<4> data input. rtcc x o dig rtcc output. t7cki x i st timer7 clock input. t5g x i st timer5 external clock gate input. ccp5 0 o dig ccp5 compare/pwm output; takes priority over port data. 1 i st ccp5 capture input. an16 1 i ana a/d input channel 17. default input configuration on por; does not affect digital output. p1d 0 o eccp1 pwm output d. may be configured for tri-state during enhanced pwm. c3inc x i ana comparator 3 input c. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 portg r g 5 ( 2 ) rg4 rg3 rg2 rg1 rg0 trisg trisg4 trisg3 trisg2 trisg1 trisg0 ancon2 ansel23 ansel22 ansel21 ansel20 ansel19 ansel18 ansel17 ansel16 odcon1 ssp1od ccp2od ccp1od ssp2od odcon2 ccp10od ( 1 ) ccp9od ( 1 ) ccp8od ccp7od ccp6od ccp5od ccp4od ccp3od odcon3 u2od u1od ctmuds legend: = unimplemented, read as 0 . shaded cells are not used by portg. note 1: unimplemented on pic18fx5k22 devices, read as 0 . 2: this bit is available when master clear is disabled (mclre = 0 ). when mclre is set, the bit is unimplemented. table 12-13: portg f unctions (continued) pin name function tris setting i/o i/o type description legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, x = dont care (tris bit does not affect port direction or is overridden for this option). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 185 pic18f87k22 family 12.9 porth, lath and trish registers porth is an 8-bit wide, bidirectional i/o port. the corresponding data direction and output latch registers are trish and lath. all pins on porth are implemented with schmitt trigger input buffers. each pin is individually configurable as an input or output. example 12-8: initializing porth note: porth is available only on the 80-pin devices. clrf porth ; initialize porth by ; clearing output ; data latches clrf lath ; alternate method ; to clear output ; data latches banksel ancon2 ; select bank with ancon2 register movlw 0fh ; configure porth as movwf ancon2 ; digital i/o movlw 0fh ; configure porth as movwf ancon1 ; digital i/o banksel trish ; select bank with trish register movlw 0cfh ; value used to ; initialize data ; direction movwf trish ; set rh3:rh0 as inputs ; rh5:rh4 as outputs ; rh7:rh6 as inputs table 12-15: po rth functions pin name function tris setting i/o i/o type description rh0/an23/a16 rh0 0 o dig lath<0> data output. 1 i st porth<0> data input. an23 1 i ana a/d input channel 23. default input configuration on por; does not affect digital input. a16 x o dig external memory interface, address line 16; takes priority over port data. rh1/an22/a17 rh1 0 o dig lath<1> data output. 1 i st porth<1> data input. an22 1 i ana a/d input channel 22. default input configuration on por; does not affect digital input. a17 x o dig external memory interface, address line 17; takes priority over port data. rh2/an21/a18 rh2 0 o dig lath<2> data output. 1 i st porth<2> data input. an21 1 i ana a/d input channel 21. default input configuration on por; does not affect digital input. a18 x o dig external memory interface, address line 18; takes priority over port data. rh3/an20/a19 rh3 0 o dig lath<3> data output. 1 i st porth<3> data input. an20 1 i ana a/d input channel 20. default input configuration on por; does not affect digital input. a19 x o dig external memory interface, address line 19; takes priority over port data. legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, x = dont care (tris bit does not affect port direction or is overridden for this opt ion). downloaded from: http:///
pic18f87k22 family ds39960d-page 186 ? 2009-2011 microchip technology inc. rh4/ccp9/ p3c/an12/ c2inc rh4 0 o dig lath<4> data output. 1 i st porth<4> data input. ccp9 0 o dig ccp9 compare/pwm output; takes priority over port data. 1 i st ccp9 capture input. p3c 0 o eccp3 pwm output c. may be configured for tri-state during enhanced pwm. an12 1 i ana a/d input channel 12. default input configuration on por; does not affect digital input. c2inc x i ana comparator 2 input c. rh5/ccp8/ p3b/an13/ c2ind rh5 0 o dig lath<5> data output. 1 i st porth<5> data input. ccp8 0 o dig ccp8 compare/pwm output; takes priority over port data. 1 i st ccp8 capture input. p3b 0 o eccp3 pwm output b. may be configured for tri-state during enhanced pwm. an13 1 i ana a/d input channel 13. default input configuration on por; does not affect digital input. c2ind x i ana comparator 2 input d. rh6/ccp7/ p1c/an14/ c1inc rh6 0 o dig lath<6> data output. 1 i st porth<6> data input. ccp7 0 o dig ccp7 compare/pwm output; takes priority over port data. 1 i st ccp7 capture input. p1c 0 o eccp1 pwm output c. may be configured for tri-state during enhanced pwm. an14 1 i ana a/d input channel 14. default input configuration on por; does not affect digital input. c1inc x i ana comparator 1 input c. rh7/ccp6/ p1b/an15 rh7 0 o dig lath<7> data output. 1 i st porth<7> data input. ccp6 0 o dig ccp6 compare/pwm output; takes priority over port data. 1 i st ccp6 capture input. p1b 0 o eccp1 pwm output b. may be configured for tri-state during enhanced pwm. an15 1 i ana a/d input channel 15. default input configuration on por; does not affect digital input. table 12-15: porth functions (continued) pin name function tris setting i/o i/o type description legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, x = dont care (tris bit does not affect port direction or is overridden for this option). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 187 pic18f87k22 family table 12-16: summary of regist ers associated with porth 12.10 portj, trisj and latj registers portj is an 8-bit wide, bidirectional port. the corresponding data direction and output latch registers are trisj and latj. all pins on portj are implemented with schmitt trigger input buffers. each pin is individually configurable as an input or output. when the external memory interface is enabled, all of the portj pins function as control outputs for the inter- face. this occurs automatically when the interface is enabled by clearing the ebdis control bit (memcon<7>). the trisj bits are also overridden. each of the portj pins has a weak internal pull-up. the pull-ups are provided to keep the inputs at a known state for the external memory interface while powering up. a single control bit can turn off all the pull-ups. this is performed by clearing bit, rjpu (padcfg1<5>). the weak pull-up is automatically turned off when the port pin is configured as an output. the pull-ups are disabled on any device reset. example 12-9: initializing portj name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 porth ( 1 ) rh7 rh6 rh5 rh4 rh3 rh2 rh1 rh0 lath ( 1 ) lath7 lath6 lath5 lath4 lath3 lath2 lath1 lath0 trish ( 1 ) trish7 trish6 trish5 trish4 trish3 trish2 trish1 trish0 ancon1 ansel15 ansel14 ansel13 ansel12 ansel11 ansel10 ansel9 ansel8 ancon2 ansel23 ansel22 ansel21 ansel20 ansel19 ansel18 ansel17 ansel16 odcon2 ccp10od ( 2 ) ccp9od ( 2 ) ccp8od ccp7od ccp6od ccp5od ccp4od ccp3od note 1: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . 2: unimplemented on pic18fx5k22 devices, read as 0 . note: portj is available only on 80-pin devices. note: these pins are configured as digital inputs on any device reset. clrf portj ; initialize portj by ; clearing output latches clrf latj ; alternate method ; to clear output latches movlw 0cfh ; value used to ; initialize data ; direction movwf trisj ; set rj3:rj0 as inputs ; rj5:rj4 as output ; rj7:rj6 as inputs downloaded from: http:///
pic18f87k22 family ds39960d-page 188 ? 2009-2011 microchip technology inc. table 12-17: po rtj functions table 12-18: summary of registers associated with portj pin name function tris setting i/o i/o type description rj0/ale rj0 0 o dig latj<0> data output. 1 i st portj<0> data input. ale x o dig external memory interface address latch enable control output; takes priority over digital i/o. rj1/oe rj1 0 o dig latj<1> data output. 1 i st portj<1> data input. oe x o dig external memory interface output enable control output; takes priority over digital i/o. rj2/wrl rj2 0 o dig latj<2> data output. 1 i st portj<2> data input. wrl x o dig external memory bus write low byte control; takes priority over digital i/o. rj3/wrh rj3 0 o dig latj<3> data output. 1 i st portj<3> data input. wrh x o dig external memory interface write high-byte control; takes priority over digital i/o. rj4/ba0 rj4 0 o dig latj<4> data output. 1 i st portj<4> data input. ba0 x o dig external memory interface byte address 0 control output; takes priority over digital i/o. rj5/ce rj5 0 o dig latj<5> data output. 1 i st portj<5> data input. ce x o dig external memory interface chip enable control output; takes priority over digital i/o. rj6/lb rj6 0 o dig latj<6> data output. 1 i st portj<6> data input. lb x o dig external memory interface lower byte enable control output; takes priority over digital i/o. rj7/ub rj7 0 o dig latj<7> data output. 1 i st portj<7> data input. ub x o dig external memory interface upper byte enable control output; takes priority over digital i/o. legend: o = output, i = input, ana = analog signal, dig = digital output, st = schmitt trigger buffer input, x = dont care (tris bit does not affect port direction or is overridden for this option). name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 portj ( 1 ) rj7 rj6 rj5 rj4 rj3 rj2 rj1 rj0 latj ( 1 ) latj7 latj6 latj5 latj4 latj3 latj2 latj1 latj0 trisj ( 1 ) trisj7 trisj6 trisj5 trisj4 trisj3 trisj2 trisj1 trisj0 padcfg1 rdpu repu rjpu ( 1 ) rtsecsel1 rtsecsel0 legend: shaded cells are not used by portj. note 1: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 189 pic18f87k22 family 12.11 parallel slave port portd can function as an 8-bit-wide parallel slave port (psp), or microprocessor port, when control bit, pspmode (pspcon<4>), is set. the port is asyn- chronously readable and writable by the external world through the rd control input pin (re0/p2d/rd /ad8) and wr control input pin (re1/p2c/wr /ad9). the psp can directly interface to an 8-bit micro- processor data bus. the external microprocessor can read or write the portd latch as an eight-bit latch. setting bit, pspmode, enables port pin, re0/p2d/rd /ad8, to be the rd input, re1/p2c/wr /ad9 to be the wr input and re2/p2b/ccp10/cs /ad10 to be the cs (chip select) input. for this functionality, the corresponding data direction bits of the trise register (trise<2:0>) must be configured as inputs (= 111 ). a write to the psp occurs when both the cs and wr lines are first detected low and ends when either are detected high. the pspif and ibf flag bits (pir1<7> and pspcon<7>, respectively) are set when the write ends. a read from the psp occurs when both the cs and rd lines are first detected low. the data in portd is read out and the obf bit (pspcon<6>) is set. if the user writes new data to portd to set obf, the data is immediately read out, but the obf bit is not set. when either the cs or rd line is detected high, the portd pins return to the input state and the pspif bit is set. user applications should wait for pspif to be set before servicing the psp. when this happens, the ibf and obf bits can be polled and the appropriate action taken. the timing for the control signals in write and read modes is shown in figure 12-4 and figure 12-5 , respectively. figure 12-3: portd and porte block diagram (parallel slave port) note: the parallel slave port is available only in microcontroller mode. data bus wr latd rdx q d ck en qd en rd portd pin (1) one bit of portd set interrupt flag pspif (pir1<7>) read chip select write rd cs wr note: the i/o pin has protection diodes to v dd and v ss . ttl ttl ttl ttl or portd rd latd data latch tris latch downloaded from: http:///
pic18f87k22 family ds39960d-page 190 ? 2009-2011 microchip technology inc. figure 12-4: parallel slave port write waveforms register 12-5: pspcon: parallel slave port co ntrol register r-0 r-0 r/w-0 r/w-0 u-0 u-0 u-0 u-0 ibf obf ibov pspmode bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 ibf: input buffer full status bit 1 = a word has been received and is waiting to be read by the cpu 0 = no word has been received bit 6 obf: output buffer full status bit 1 = the output buffer still holds a previously written word 0 = the output buffer has been read bit 5 ibov: input buffer overflow detect bit 1 = a write occurred when a previously input word had not been read (must be cleared in software) 0 = no overflow occurred bit 4 pspmode: parallel slave port mode select bit 1 = parallel slave port mode 0 = general purpose i/o mode bit 3-0 unimplemented: read as 0 q1 q2 q3 q4 cs q1 q2 q3 q4 q1 q2 q3 q4 wr rd ibf obf pspif portd<7:0> downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 191 pic18f87k22 family figure 12-5: parallel slave port read waveforms table 12-19: registers associated with parallel slave port name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 portd rd7 rd6 rd5 rd4 rd3 rd2 rd1 rd0 latd latd7 latd6 latd5 latd4 latd3 latd2 latd1 latd0 trisd trisd7 trisd6 trisd5 trisd4 trisd3 trisd2 trisd1 trisd0 porte re7 re6 re5 re4 re3 re2 re1 re0 late late7 late6 late5 late4 late3 late2 late1 late0 trise trise7 trise6 trise5 trise4 trise3 trise2 trise1 trise0 pspcon ibf obf ibov pspmode intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir1 pspif adif rc1if tx1if ssp1if tmr1gif tmr2if tmr1if pie1 pspie adie rc1ie tx1ie ssp1ie tmr1gie tmr2ie tmr1ie ipr1 pspip adip rc1ip tx1ip ssp1ip tmr1gip tmr2ip tmr1ip pmd1 pspmd ctmumd rtccmd tmr4md tmr3md tmr2md tmr1md embdm legend: = unimplemented, read as 0 . shaded cells are not used by the parallel slave port. q1 q2 q3 q4 cs q1 q2 q3 q4 q1 q2 q3 q4 wr ibf pspif rd obf portd<7:0> downloaded from: http:///
pic18f87k22 family ds39960d-page 192 ? 2009-2011 microchip technology inc. notes: downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 193 pic18f87k22 family 13.0 timer0 module the timer0 module incorporates the following features: software-selectable operation as a timer or counter in both 8-bit or 16-bit modes readable and writable registers dedicated 8-bit, software programmable prescaler selectable clock source (internal or external) edge select for external clock interrupt-on-overflow the t0con register ( register 13-1 ) controls all aspects of the modules operation, including the prescale selection. it is both readable and writable. figure 13-1 provides a simplified block diagram of the timer0 module in 8-bit mode. figure 13-2 provides a simplified block diagram of the timer0 module in 16-bit mode. register 13-1: t0con: ti mer0 control register r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 tmr0on t08bit t0cs t0se psa t0ps2 t0ps1 t0ps0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 tmr0on: timer0 on/off control bit 1 = enables timer0 0 = stops timer0 bit 6 t08bit : timer0 8-bit/16-bit control bit 1 = timer0 is configured as an 8-bit timer/counter 0 = timer0 is configured as a 16-bit timer/counter bit 5 t0cs : timer0 clock source select bit 1 = transition on t0cki pin input edge 0 = internal clock (f osc /4) bit 4 t0se : timer0 source edge select bit 1 = increment on high-to-low transition on t0cki pin 0 = increment on low-to-high transition on t0cki pin bit 3 psa : timer0 prescaler assignment bit 1 = timer0 prescaler is not assigned; timer0 clock input bypasses prescaler 0 = timer0 prescaler is assigned; timer0 clock input comes from prescaler output bit 2-0 t0ps<2:0> : timer0 prescaler select bits 111 = 1:256 prescale value 110 = 1:128 prescale value 101 = 1:64 prescale value 100 = 1:32 prescale value 011 = 1:16 prescale value 010 = 1:8 prescale value 001 = 1:4 prescale value 000 = 1:2 prescale value downloaded from: http:///
pic18f87k22 family ds39960d-page 194 ? 2009-2011 microchip technology inc. 13.1 timer0 operation timer0 can operate as either a timer or a counter. the mode is selected with the t0cs bit (t0con<5>). in timer mode (t0cs = 0 ), the module increments on every clock by default unless a different prescaler value is selected (see section 13.3 prescaler ). if the tmr0 register is written to, the increment is inhibited for the following two instruction cycles. the user can work around this by writing an adjusted value to the tmr0 register. the counter mode is selected by setting the t0cs bit (= 1 ). in this mode, timer0 increments either on every rising edge or falling edge of the t0cki pin. the incrementing edge is determined by the timer0 source edge select bit, t0se (t0con<4>); clearing this bit selects the rising edge. restrictions on the external clock input are discussed below. an external clock source can be used to drive timer0; however, it must meet certain requirements to ensure that the external clock can be synchronized with the internal phase clock (t osc ). there is a delay between synchronization and the onset of incrementing the timer/counter. 13.2 timer0 reads and writes in 16-bit mode tmr0h is not the actual high byte of timer0 in 16-bit mode. it is actually a buffered version of the real high byte of timer0, which is not directly readable nor writable (see figure 13-2 ). tmr0h is updated with the contents of the high byte of timer0 during a read of tmr0l. this provides the ability to read all 16 bits of timer0 without having to verify that the read of the high and low byte was valid, due to a rollover between successive reads of the high and low byte. similarly, a write to the high byte of timer0 must also take place through the tmr0h buffer register. the high byte is updated with the contents of tmr0h when a write occurs to tmr0l. this allows all 16 bits of timer0 to be updated at once. figure 13-1: timer0 block diagram (8-bit mode) figure 13-2: timer0 block di agram (16-bit mode) note: upon reset, timer0 is enabled in 8-bit mode with clock input from t0cki max. prescale. t0cki pin t0se 0 1 1 0 t0cs f osc /4 programmable prescaler sync with internal clocks tmr0l (2 t cy delay) internal data bus psa t0ps<2:0> set tmr0if on overflow 3 8 8 note: upon reset, timer0 is enabled in 8-bit mode wit h clock input from t0cki max. prescale. t0cki pin t0se 0 1 1 0 t0cs f osc /4 sync with internal clocks tmr0l (2 t cy delay) internal data bus 8 psa t0ps<2:0> set tmr0if on overflow 3 tmr0 tmr0h high byte 8 8 8 read tmr0l write tmr0l 8 programmable prescaler downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 195 pic18f87k22 family 13.3 prescaler an 8-bit counter is available as a prescaler for the timer0 module. the prescaler is not directly readable or writable. its value is set by the psa and t0ps<2:0> bits (t0con<3:0>), which determine the prescaler assignment and prescale ratio. clearing the psa bit assigns the prescaler to the timer0 module. when it is assigned, prescale values from 1:2 through 1:256, in power-of-two increments, are selectable. when assigned to the timer0 module, all instructions writing to the tmr0 register (for example, clrf tmr0 , movwf tmr0 , bsf tmr0 ) clear the prescaler count. 13.3.1 switching prescaler assignment the prescaler assignment is fully under software control and can be changed on-the-fly during program execution. 13.4 timer0 interrupt the tmr0 interrupt is generated when the tmr0 register overflows from ffh to 00h in 8-bit mode, or from ffffh to 0000h in 16-bit mode. this overflow sets the tmr0if flag bit. the interrupt can be masked by clearing the tmr0ie bit (intcon<5>). before re- enabling the interrupt, the tmr0if bit must be cleared in software by the interrupt service routine (isr). since timer0 is shut down in sleep mode, the tmr0 interrupt cannot awaken the processor from sleep. table 13-1: registers associated with timer0 note: writing to tmr0 when the prescaler is assigned to timer0 will clear the prescaler count but will not change the prescaler assignment. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 tmr0l timer0 register low byte tmr0h timer0 register high byte intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif t0con tmr0on t08bit t0cs t0se psa t0ps2 t0ps1 t0ps0 legend: = unimplemented, read as 0 . shaded cells are not used by timer0. downloaded from: http:///
pic18f87k22 family ds39960d-page 196 ? 2009-2011 microchip technology inc. notes: downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 197 pic18f87k22 family 14.0 timer1 module the timer1 timer/counter module incorporates these features: software-selectable operation as a 16-bit timer or counter readable and writable 8-bit registers (tmr1h and tmr1l) selectable clock source (internal or external) with device clock or sosc oscillator internal options interrupt-on-overflow reset on eccp special event trigger timer with gated control figure 14-1 displays a simplified block diagram of the timer1 module. the timer1 oscillator can also be used as a low-power clock source for the microcontroller in power-managed operation. the timer1 can also work on the sosc oscillator. timer1 is controlled through the t1con control register ( register 14-1 ). it also contains the secondary oscillator enable bit (soscen). timer1 can be enabled or disabled by setting or clearing control bit, tmr1on (t1con<0>). the f osc clock source should not be used with the eccp capture/compare features. if the timer will be used with the capture or compare features, always select one of the other timer clocking options. register 14-1: t1con: ti mer1 control register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 tmr1cs1 tmr1cs0 t1ckps1 t1ckps0 soscen t1sync rd16 tmr1on bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-6 tmr1cs<1:0>: timer1 clock source select bits 10 = timer1 clock source is either from a pin or oscillator, depending on the soscen bit: soscen = 0 : external clock from the t1cki pin (on the rising edge). soscen = 1 : depending on the soscsel configuration bit, the clock source is either a crystal oscillator on the sosci/sosco pins or an internal clock from the sclki pin. 01 = timer1 clock source is the system clock (f osc ) ( 1 ) 00 = timer1 clock source is the instruction clock (f osc /4) bit 5-4 t1ckps<1:0>: timer1 input clock prescale select bits 11 = 1:8 prescale value 10 = 1:4 prescale value 01 = 1:2 prescale value 00 = 1:1 prescale value bit 3 soscen: sosc oscillator enable bit 1 = sosc is enabled and available for timer1 0 = sosc is disabled for timer1 the oscillator inverter and feedback resistor are turned off to eliminate power drain. bit 2 t1sync : timer1 external clock input synchronization select bit tmr1cs<1:0> = 10 : 1 = do not synchronize external clock input 0 = synchronize external clock input tmr1cs<1:0> = 0x : this bit is ignored. timer1 uses the internal clock when tmr1cs<1:0> = 1x . bit 1 rd16: 16-bit read/write mode enable bit 1 = enables register read/write of timer1 in one 16-bit operation 0 = enables register read/write of timer1 in two 8-bit operations bit 0 tmr1on: timer1 on bit 1 = enables timer1 0 =stops timer1 note 1: the f osc clock source should not be selected if the timer will be used with the eccp capture/compare features. downloaded from: http:///
pic18f87k22 family ds39960d-page 198 ? 2009-2011 microchip technology inc. 14.1 timer1 gate control register the timer1 gate control register (t1gcon), displayed in register 14-2 , is used to control the timer1 gate. register 14-2: t1gcon: timer1 gate control register ( 1 ) r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r-x r/w-0 r/w-0 tmr1ge t1gpol t1gtm t1gspm t1ggo/t1done t1gval t1gss1 t1gss0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 tmr1ge: timer1 gate enable bit if tmr1on = 0 : this bit is ignored. if tmr1on = 1 : 1 = timer1 counting is controlled by the timer1 gate function 0 = timer1 counts regardless of timer1 gate function bit 6 t1gpol: timer1 gate polarity bit 1 = timer1 gate is active-high (timer1 counts when gate is high) 0 = timer1 gate is active-low (timer1 counts when gate is low) bit 5 t1gtm: timer1 gate toggle mode bit 1 = timer1 gate toggle mode is enabled 0 = timer1 gate toggle mode is disabled and toggle flip-flop is cleared timer1 gate flip-flop toggles on every rising edge. bit 4 t1gspm: timer1 gate single pulse mode bit 1 = timer1 gate single pulse mode is enabled and is controlling timer1 gate 0 = timer1 gate single pulse mode is disabled bit 3 t1ggo/t1done : timer1 gate single pulse acquisition status bit 1 = timer1 gate single pulse acquisition is ready, waiting for an edge 0 = timer1 gate single pulse acquisition has completed or has not been started this bit is automatically cleared when t1gspm is cleared. bit 2 t1gval: timer1 gate current state bit indicates the current state of the timer1 gate that could be provided to tmr1h:tmr1l; unaffected by timer1 gate enable (tmr1ge) bit. bit 1-0 t1gss<1:0>: timer1 gate source select bits 11 = comparator 2 output 10 = comparator 1 output 01 = tmr2 to match pr2 output 00 = timer1 gate pin note 1: programming the t1gcon prior to t1con is recommended. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 199 pic18f87k22 family 14.2 timer1 operation the timer1 module is an 8 or 16-bit incrementing counter that is accessed through the tmr1h:tmr1l register pair. when used with an internal clock source, the module is a timer and increments on every instruction cycle. when used with an external clock source, the module can be used as either a timer or counter. it increments on every selected edge of the external source. timer1 is enabled by configuring the tmr1on and tmr1ge bits in the t1con and t1gcon registers, respectively. when sosc is selected as crystal mode (by soscsel), the rc1/sosci/eccp2/p2a and rc0/ sosco/sclki pins become inputs. this means the values of trisc<1:0> are ignored and the pins are read as 0 . 14.3 clock source selection the tmr1cs<1:0> and soscen bits of the t1con register are used to select the clock source for timer1. register 14-1 displays the clock source selections. 14.3.1 internal clock source when the internal clock source is selected, the tmr1h:tmr1l register pair will increment on multiples of f osc , as determined by the timer1 prescaler. 14.3.2 external clock source when the external clock source is selected, the timer1 module may work as a timer or a counter. when enabled to count, timer1 is incremented on the rising edge of the external clock input, t1cki. either of these external clock sources can be synchronized to the microcontroller system clock or they can run asynchronously. when used as a timer with a clock oscillator, an external, 32.768 khz crystal can be used in conjunction with the dedicated internal oscillator circuit. table 14-1: timer1 clo ck source selection note: in counter mode, a falling edge must be registered by the counter prior to the first incrementing rising edge after any one or more of the following conditions: timer1 enabled after por reset write to tmr1h or tmr1l timer1 is disabled timer1 is disabled (tmr1on = 0 ) when t1cki is high, timer1 is enabled (tmr1on = 1 ) when t1cki is low. tmr1cs1 tmr1cs0 soscen clock source 01x clock source (f osc ) 00x instruction clock (f osc /4) 100 external clock on t1cki pin 101 oscillator circuit on sosci/sosco pins downloaded from: http:///
pic18f87k22 family ds39960d-page 200 ? 2009-2011 microchip technology inc. figure 14-1: timer1 block diagram tmr1h tmr1l t1sync t1ckps<1:0> prescaler 1, 2, 4, 8 01 synchronized clock input 2 set flag bit, tmr1if, on overflow tmr1 (2) tmr1on note 1: st buffer is a high-speed type when using t1cki. 2: timer1 register increments on rising edge. 3: synchronization does not operate while in sleep. 4: the output of sosc is determined by the soscsel<1:0> configuration bits. t1g sosc f osc /4 internal clock sosco/sclki sosci 10 t1cki tmr1cs<1:0> (1) synchronize (3) det sleep input tmr1ge 01 00 01 10 11 from tmr2 from comparator 1 t1gpol d q ck q 01 t1gval t1gtm single pulse acq. control t1gspm t1ggo/t1done t1gss<1:0> en out (4) 1000 01 f osc internal clock from comparator 2 match pr2 r d en q q1 rd t1gcon data bus det interrupt tmr1gif set t1clk f osc /2 internal clock d en q t1g_in tmr1on output output t1con.soscen t3con.soscen soscgo scs<1:0> = 01 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 201 pic18f87k22 family 14.4 timer1 16-bit read/write mode timer1 can be configured for 16-bit reads and writes. when the rd16 control bit (t1con<1>) is set, the address for tmr1h is mapped to a buffer register for the high byte of timer1. a read from tmr1l loads the contents of the high byte of timer1 into the timer1 high byte buffer register. this provides the user with the ability to accurately read all 16 bits of timer1 without having to determine whether a read of the high byte, followed by a read of the low byte, has become invalid due to a rollover between reads. a write to the high byte of timer1 must also take place through the tmr1h buffer register. the timer1 high byte is updated with the contents of tmr1h when a write occurs to tmr1l. this allows a user to write all 16 bits at once to both the high and low bytes of timer1. the high byte of timer1 is not directly readable or writable in this mode. all reads and writes must take place through the timer1 high byte buffer register. writes to tmr1h do not clear the timer1 prescaler; the prescaler is only cleared on writes to tmr1l. 14.5 sosc oscillator an on-chip crystal oscillator circuit is incorporated between pins, sosci (input) and sosco (amplifier output). it is enabled by any peripheral that requests it. there are eight ways the sosc can be enabled: if the sosc is selected as the source by any of the odd timers, which is done by each respective soscen bit (txcon<3>), if the sosc is selected as the rtcc source by the rtcosc configuration bit (config3l<1>), if the sosc is selected as the cpu clock source by the scs bits (osccon<1:0>) or if the soscgo bit is set (osccon2<3>). the soscgo bit is used to warm up the sosc so that it is ready before any peripheral requests it. the oscillator is a low-power circuit, rated for 32 khz crystals. it will continue to run during all power-managed modes. the circuit for a typi- cal low-power oscillator is depicted in figure 14-2 . table 14-2 provides the capacitor selection for the sosc oscillator. the user must provide a software time delay to ensure proper start-up of the sosc oscillator. figure 14-2: external components for the sosc low-power oscillator table 14-2: capacitor selection for the timer oscillator ( 2,3,4,5 ) the sosc crystal oscillator drive level is determined based on the soscsel<1:0> (config1l<4:3>) con- figuration bits. the higher drive level mode, soscsel<1:0> = 11 , is intended to drive a wide variety of 32.768 khz crystals with a variety of capacitance load (cl) ratings. oscillator type freq. c1 c2 lp 32 khz 12 pf ( 1 ) 12 pf ( 1 ) note 1: microchip suggests these values as a starting point in validating the oscillator circuit. 2: higher capacitance increases the stabil- ity of the oscillator, but also increases the start-up time. 3: since each resonator/crystal has its own characteristics, the user should consult the resonator/crystal manufacturer for appropriate values of external components. 4: capacitor values are for design guid- ance only. values listed would be typical of a cl = 10 pf rated crystal when soscsel<1:0> = 11 . 5: incorrect capacitance value may result in a frequency not meeting the crystal manufacturers tolerance specification. note: see the notes with table 14-2 for additional information about capacitor selection. c1 c2 xtal sosci sosco 32.768 khz 12 pf 12 pf pic18f87k22 downloaded from: http:///
pic18f87k22 family ds39960d-page 202 ? 2009-2011 microchip technology inc. the lower drive level mode is highly optimized for extremely low-power consumption. it is not intended to drive all types of 32.768 khz crystals. in the low drive level mode, the crystal oscillator circuit may not work correctly if excessively large discrete capacitors are placed on the sosco and sosci pins. this mode is designed to work only with discrete capacitances of approximately 3 pf-10 pf on each pin. crystal manufacturers usually specify a cl (capaci- tance load) rating for their crystals. this value is related to, but not necessarily the same as, the values that should be used for c1 and c2 in figure 14-2 . for more details on selecting the optimum c1 and c2 for a given crystal, see the crystal manufacturers appli- cations information. the optimum value depends, in part, on the amount of parasitic capacitance in the circuit, which is often unknown. for that reason, it is highly recommended that thorough testing and valida- tion of the oscillator be performed after values have been selected. 14.5.1 using sosc as a clock source the sosc oscillator is also available as a clock source in power-managed modes. by setting the system clock select bits, scs<1:0> (osccon<1:0>), to 01 , the device switches to sec_run mode, and both the cpu and peripherals are clocked from the sosc oscil- lator. if the idlen bit (osccon<7>) is cleared and a sleep instruction is executed, the device enters sec_idle mode. additional details are available in section 4.0 power-managed modes . whenever the sosc oscillator is providing the clock source, the sosc system clock status flag, soscrun (osccon2<6>), is set. this can be used to determine the controllers current clocking mode. it can also indicate the clock source currently being used by the fail-safe clock monitor (fscm). if the clock monitor is enabled and the sosc oscillator fails while providing the clock, polling the socsrun bit will indicate whether the clock is being provided by the sosc oscillator or another source. 14.5.2 sosc oscillator layout considerations the sosc oscillator circuit draws very little power during operation. due to the low-power nature of the oscillator, it may also be sensitive to rapidly changing signals in close proximity. this is especially true when the oscillator is configured for extremely low-power mode, soscsel<1:0> (config1l<4:3>) = 01 . the oscillator circuit, displayed in figure 14-2 , should be located as close as possible to the microcontroller. there should be no circuits passing within the oscillator circuit boundaries other than v ss or v dd . if a high-speed circuit must be located near the oscillator, it may help to have a grounded guard ring around the oscillator circuit. the guard, as displayed in figure 14-3 , could be used on a single-sided pcb or in addition to a ground plane. (examples of a high-speed circuit include the eccp1 pin, in output compare or pwm mode, or the primary oscillator using the osc2 pin.) figure 14-3: oscillator circuit with grounded guard ring in the low drive level mode, soscsel<1:0> = 01 , it is critical that rc2 i/o pin signals be kept away from the oscillator circuit. configuring rc2 as a digital output, and toggling it, can potentially disturb the oscillator circuit, even with a relatively good pcb layout. if possible, either leave rc2 unused or use it as an input pin with a slew rate limited signal source. if rc2 must be used as a digital output, it may be necessary to use the higher drive level oscillator mode (soscsel<1:0> = 11 ) with many pcb layouts. even in the higher drive level mode, careful layout procedures should still be followed when designing the oscillator circuit. in addition to dv/dt induced noise considerations, it is important to ensure that the circuit board is clean. even a very small amount of conductive soldering flux residue can cause pcb leakage currents that can overwhelm the oscillator circuit. 14.6 timer1 interrupt the tmr1 register pair (tmr1h:tmr1l) increments from 0000h to ffffh and rolls over to 0000h. the timer1 interrupt, if enabled, is generated on overflow which is latched in interrupt flag bit, tmr1if (pir1<0>). this interrupt can be enabled or disabled by setting or clearing the timer1 interrupt enable bit, tmr1ie (pie1<0>). v dd osc1 v ss osc2 rc0 rc1 rc2 note: not drawn to scale. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 203 pic18f87k22 family 14.7 resetting timer1 using the eccp special event trigger if eccp modules are configured to use timer1 and to generate a special event trigger in compare mode (ccpxm<3:0> = 1011 ), this signal will reset timer1. the trigger from eccp2 will also start an a/d conversion, if the a/d module is enabled. (for more information, see section 20.3.4 special event trigger .) to take advantage of this feature, the module must be configured as either a timer or a synchronous counter. when used this way, the ccprxh:ccprxl register pair effectively becomes a period register for timer1. if timer1 is running in asynchronous counter mode, this reset operation may not work. in the event that a write to timer1 coincides with a special event trigger, the write operation will take precedence. 14.8 timer1 gate timer1 can be configured to count freely or the count can be enabled and disabled using the timer1 gate circuitry. this is also referred to as timer1 gate count enable. timer1 gate can also be driven by multiple selectable sources. 14.8.1 timer1 gate count enable the timer1 gate enable mode is enabled by setting the tmr1ge bit of the t1gcon register. the polarity of the timer1 gate enable mode is configured using the t1gpol bit (t1gcon<6>). when timer1 gate enable mode is enabled, timer1 will increment on the rising edge of the timer1 clock source. when timer1 gate enable mode is disabled, no incrementing will occur and timer1 will hold the current count. see figure 14-4 for timing details. table 14-3: timer1 gate enable selections note: the special event trigger from the eccpx module will only clear the tmr1 registers content, but not set the tmr1if interrupt flag bit (pir1<0>). t1clk ( ? ) t1gpol (t1gcon<6>) t1g pin timer1 operation ? 00 counts ? 01 holds count ? 10 holds count ? 11 counts ? the clock on which tmr1 is running. for more information, see figure 14-1 . note: the ccp and eccp modules use timers, 1 through 8, for some modes. the assign- ment of a particular timer to a ccp/eccp module is determined by the timer to ccp enable bits in the ccptmrsx registers. for more details, see register 19-2 , register 19-3 and register 20-2 . downloaded from: http:///
pic18f87k22 family ds39960d-page 204 ? 2009-2011 microchip technology inc. figure 14-4: timer1 gate count enable mode 14.8.2 timer1 gate source selection the timer1 gate source can be selected from one of four sources. source selection is controlled by the t1gssx (t1gcon<1:0>) bits (see table 14-4 ). table 14-4: timer1 gate sources the polarity for each available source is also selectable, controlled by the t1gpol bit (t1gcon<6>). 14.8.2.1 t1g pin gate operation the t1g pin is one source for timer1 gate control. it can be used to supply an external source to the timer1 gate circuitry. 14.8.2.2 timer2 match gate operation the tmr2 register will increment until it matches the value in the pr2 register. on the very next increment cycle, tmr2 will be reset to 00h. when this reset occurs, a low-to-high pulse will automatically be gener- ated and internally supplied to the timer1 gate circuitry. the pulse will remain high for one instruction cycle and will return back to a low state until the next match. the t1gpol bit determines when the timer1 counter increments based on this pulse. when t1gpol = 1 , timer1 increments for a single instruction cycle follow- ing a tmr2 match with pr2. when t1gpol = 0 , timer1 increments continuously, except for the cycle following the match, when the gate signal goes from low-to-high. 14.8.2.3 comparator 1 output gate operation the output of comparator 1 can be internally supplied to the timer1 gate circuitry. after setting up comparator 1 with the cm1con register, timer1 will increment depending on the transitions of the cmp1out (cmstat<5>) bit. 14.8.2.4 comparator 2 output gate operation the output of comparator 2 can be internally supplied to the timer1 gate circuitry. after setting up comparator 2 with the cm2con register, timer1 will increment depending on the transitions of the cmp2out (cmstat<6>) bit. tmr1ge t1gpol t1g_in t1cki t1gval timer1 n n + 1 n + 2 n + 3 n + 4 t1gss<1:0> timer1 gate source 00 timer1 gate pin 01 tmr2 to match pr2 (tmr2 increments to match pr2) 10 comparator 1 output (comparator logic high output) 11 comparator 2 output (comparator logic high output) downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 205 pic18f87k22 family 14.8.3 timer1 gate toggle mode when timer1 gate toggle mode is enabled, it is possible to measure the full cycle length of a timer1 gate signal, as opposed to the duration of a single level pulse. the timer1 gate source is routed through a flip-flop that changes state on every incrementing edge of the signal. (for timing details, see figure 14-5 .) the t1gval bit (t1gcon<2>) indicates when the toggled mode is active and the timer is counting. the timer1 gate toggle mode is enabled by setting the t1gtm bit (t1gcon<5>). when t1gtm is cleared, the flip-flop is cleared and held clear. this is necessary in order to control which edge is measured. figure 14-5: timer1 gate toggle mode tmr1ge t1gpol t1gtm t1g_in t1cki t1gval timer1 n n + 1 n + 2 n + 3 n + 4 n + 5 n + 6 n + 7 n + 8 downloaded from: http:///
pic18f87k22 family ds39960d-page 206 ? 2009-2011 microchip technology inc. 14.8.4 timer1 gate single pulse mode when timer1 gate single pulse mode is enabled, it is possible to capture a single pulse gate event. timer1 gate single pulse mode is enabled by setting the t1gspm bit (t1gcon<4>) and the t1ggo/t1done bit (t1gcon<3>). the timer1 will be fully enabled on the next incrementing edge. on the next trailing edge of the pulse, the t1ggo/ t1done bit will automatically be cleared. no other gate events will be allowed to increment timer1 until the t1ggo/t1done bit is once again set in software. clearing the t1gspm bit of the t1gcon register will also clear the t1ggo/t1done bit. (for timing details, see figure 14-6 .) simultaneously enabling the toggle and single pulse modes will permit both sections to work together. this allows the cycle times on the timer1 gate source to be measured. (for timing details, see figure 14-7 .) 14.8.5 timer1 gate value status when the timer1 gate value status is utilized, it is possible to read the most current level of the gate control value. the value is stored in the t1gval bit (t1gcon<2>). this bit is valid even when the timer1 gate is not enabled (tmr1ge bit is cleared). figure 14-6: timer1 gate single pulse mode tmr1ge t1gpol t1g_in t1cki t1gval timer1 n n + 1 n + 2 t1gspm t1ggo/ t1done set by software cleared by hardware on falling edge of t1gval set by hardware on falling edge of t1gval cleared by software cleared by software rtccif counting enabled on rising edge of t1g downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 207 pic18f87k22 family figure 14-7: timer1 gate single pulse and toggle combined mode table 14-5: registers associated with timer1 as a timer/counter name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir1 pspif adif rc1if tx1if ssp1if tmr1gif tmr2if tmr1if pie1 pspie adie rc1ie tx1ie ssp1ie tmr1gie tmr2ie tmr1ie ipr1 pspip adip rc1ip tx1ip ssp1ip tmr1gip tmr2ip tmr1ip tmr1l timer1 register low byte tmr1h timer1 register high byte t1con tmr1cs1 tmr1cs0 t1ckps1 t1ckps0 soscen t1sync rd16 tmr1on t1gcon tmr1ge t1gpol t1gtm t1gspm t1ggo/ t1done t1gval t1gss1 t1gss0 osccon2 soscrun s o s c g o mfiofs mfiosel pmd1 pspmd ctmumd rtccmd tmr4md tmr3md tmr2md tmr1md embdm legend: shaded cells are not used by the timer1 module. note 1: unimplemented on 32-kbyte devices (pic18fx5k22). tmr1ge t1gpol t1g_in t1cki t1gval timer1 n n + 1 n + 2 t1gspm t1ggo/ t1done set by software cleared by hardware on falling edge of t1gval set by hardware on falling edge of t1gval cleared by software cleared by software rtccif t1gtm counting enabled on rising edge of t1g n + 4 n + 3 downloaded from: http:///
pic18f87k22 family ds39960d-page 208 ? 2009-2011 microchip technology inc. notes: downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 209 pic18f87k22 family 15.0 timer2 module the timer2 module incorporates the following features: eight-bit timer and period registers (tmr2 and pr2, respectively) both registers are readable and writable software programmable prescaler (1:1, 1:4 and 1:16) software programmable postscaler (1:1 through 1:16) interrupt on tmr2 to pr2 match optional use as the shift clock for the mssp modules this module is controlled through the t2con register ( register 15-1 ) that enables or disables the timer, and configures the prescaler and postscaler. timer2 can be shut off by clearing control bit, tmr2on (t2con<2>), to minimize power consumption. a simplified block diagram of the module is shown in figure 15-1 . 15.1 timer2 operation in normal operation, tmr2 is incremented from 00h on each clock (f osc /4). a four-bit counter/prescaler on the clock input gives the prescale options of direct input, divide-by-4 or divide-by-16. these are selected by the prescaler control bits, t2ckps<1:0> (t2con<1:0>). the value of tmr2 is compared to that of the period reg- ister, pr2, on each clock cycle. when the two values match, the comparator generates a match signal as the timer output. this signal also resets the value of tmr2 to 00h on the next cycle and drives the output counter/ postscaler. (see section 15.2 timer2 interrupt .) the tmr2 and pr2 registers are both directly readable and writable. the tmr2 register is cleared on any device reset, while the pr2 register initializes at ffh. both the prescaler and postscaler counters are cleared on the following events: a write to the tmr2 register a write to the t2con register any device reset C power-on reset (por), mclr reset, watchdog timer reset (wdtr) or brown-out reset (bor) tmr2 is not cleared when t2con is written. note: the ccp and eccp modules use timers, 1 through 8, for some modes. the assign- ment of a particular timer to a ccp/eccp module is determined by the timer to ccp enable bits in the ccptmrsx registers. for more details, see register 20-2 , register 19-2 and register 19-3 . register 15-1: t2con: ti mer2 control register u-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 t2outps3 t2outps2 t2outps1 t2outps0 tmr2on t2ckps1 t2ckps0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 unimplemented: read as 0 bit 6-3 t2outps<3:0>: timer2 output postscale select bits 0000 = 1:1 postscale 0001 = 1:2 postscale 1111 = 1:16 postscale bit 2 tmr2on: timer2 on bit 1 = timer2 is on 0 = timer2 is off bit 1-0 t2ckps<1:0>: timer2 clock prescale select bits 00 = prescaler is 1 01 = prescaler is 4 1x = prescaler is 16 downloaded from: http:///
pic18f87k22 family ds39960d-page 210 ? 2009-2011 microchip technology inc. 15.2 timer2 interrupt timer2 can also generate an optional device interrupt. the timer2 output signal (tmr2 to pr2 match) provides the input for the 4-bit output counter/postscaler. this counter generates the tmr2 match interrupt flag, which is latched in tmr2if (pir1<1>). the interrupt is enabled by setting the tmr2 match interrupt enable bit, tmr2ie (pie1<1>). a range of 16 postscaler options (from 1:1 through 1:16 inclusive) can be selected with the postscaler control bits, t2outps<3:0> (t2con<6:3>). 15.3 timer2 output the unscaled output of tmr2 is available primarily to the eccp modules, where it is used as a time base for operations in pwm mode. timer2 can optionally be used as the shift clock source for the mssp modules operating in spi mode. additional information is provided in section 21.0 master synchronous serial port (mssp) module . figure 15-1: timer2 block diagram table 15-1: registers associated with timer2 as a timer/counter name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir1 pspif adif rc1if tx1if ssp1if tmr1gif tmr2if tmr1if pie1 pspie adie rc1ie tx1ie ssp1ie tmr1gie tmr2ie tmr1ie ipr1 pspip adip rc1ip tx1ip ssp1ip tmr1gip tmr2ip tmr1ip tmr2 timer2 register t2con t2outps3 t2outps2 t2outps1 t2outps0 tmr2on t2ckps1 t2ckps0 pr2 timer2 period register pmd1 pspmd ctmumd rtccmd tmr4md tmr3md tmr2md tmr1md embdm legend: = unimplemented, read as 0 . shaded cells are not used by the timer2 module. comparator tmr2 output tmr2 postscaler prescaler pr2 2 f osc /4 1:1 to 1:16 1:1, 1:4, 1:16 4 t2outps<3:0> t2ckps<1:0> set tmr2if internal data bus 8 reset tmr2/pr2 8 8 (to pwm or msspx) match downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 211 pic18f87k22 family 16.0 timer3/5/7 modules the timer3/5/7 timer/counter modules incorporate these features: software-selectable operation as a 16-bit timer or counter readable and writable eight-bit registers (tmrxh and tmrxl) selectable clock source (internal or external) with device clock or sosc oscillator internal options interrupt-on-overflow module reset on eccp special event trigger timer7 is unimplemented for devices with a program memory of 32 kbytes (pic18fx5k22). a simplified block diagram of the timer3/5/7 module is shown in figure 16-1 . the timer3/5/7 module is controlled through the txcon register ( register 16-1 ). it also selects the clock source options for the eccp modules. (for more information, see section 20.1.1 eccp module and timer resources .) the f osc clock source should not be used with the eccp capture/compare features. if the timer will be used with the capture or compare features, always select one of the other timer clocking options. note: throughout this section, generic references are used for register and bit names that are the same C except for an x variable that indicates the items association with the timer3, timer5 or timer7 module. for example, the control register is named txcon and refers to t3con, t5con and t7con. downloaded from: http:///
pic18f87k22 family ds39960d-page 212 ? 2009-2011 microchip technology inc. register 16-1: txcon: ti merx control register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 tmrxcs1 tmrxcs0 txckps1 txckps0 soscen txsync rd16 tmrxon bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-6 tmrxcs<1:0>: timerx clock source select bits 10 = timer1 clock source depends on the soscen bit: soscen = 0 : external clock from the t1cki pin (on the rising edge). soscen = 1 : depending on the soscsel fuses, either a crystal oscillator on the sosci/sosco pins or an external clock from the sclki pin. 01 = timerx clock source is the system clock (f osc ) ( 1 ) 00 = timerx clock source is the instruction clock (f osc /4) bit 5-4 txckps<1:0> : timerx input clock prescale select bits 11 = 1:8 prescale value 10 = 1:4 prescale value 01 = 1:2 prescale value 00 = 1:1 prescale value bit 3 soscen : sosc oscillator enable bit 1 = sosc/sclki are enabled for timerx (based on the soscsel fuses) 0 = sosc/sclki are disabled for timerx and txcki is enabled bit 2 txsync : timerx external clock input synchronization control bit (not usable if the device clock comes from timer1/timer3.) when tmrxcs<1:0> = 10 : 1 = do not synchronize external clock input 0 = synchronize external clock input when tmrxcs<1:0> = 0x : this bit is ignored; timer3 uses the internal clock. bit 1 rd16: 16-bit read/write mode enable bit 1 = enables register read/write of timerx in one 16-bit operation 0 = enables register read/write of timerx in two eight-bit operations bit 0 tmrxon: timerx on bit 1 = enables timerx 0 = stops timerx note 1: the f osc clock source should not be selected if the timer will be used with the eccp capture/compare features. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 213 pic18f87k22 family 16.1 timer3/5/7 gate control register the timer3/5/7 gate control register (txgcon), provided in register 14-2, is used to control the timerx gate. register 16-2: txgcon: timerx gate control register ( 1 ) r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r-x r/w-0 r/w-0 tmrxge txgpol txgtm txgspm txggo/txdone txgval txgss1 txgss0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 tmrxge: timerx gate enable bit if tmrxon = 0 : this bit is ignored. if tmrxon = 1 : 1 = timerx counting is controlled by the timerx gate function 0 = timerx counts regardless of timerx gate function bit 6 txgpol: timerx gate polarity bit 1 = timerx gate is active-high (timerx counts when gate is high) 0 = timerx gate is active-low (timerx counts when gate is low) bit 5 txgtm: timerx gate toggle mode bit 1 = timerx gate toggle mode is enabled. 0 = timerx gate toggle mode is disabled and toggle flip-flop is cleared timerx gate flip-flop toggles on every rising edge. bit 4 txgspm: timerx gate single pulse mode bit 1 = timerx gate single pulse mode is enabled and is controlling timerx gate 0 = timerx gate single pulse mode is disabled bit 3 txggo/txdone : timerx gate single pulse acquisition status bit 1 = timerx gate single pulse acquisition is ready, waiting for an edge 0 = timerx gate single pulse acquisition has completed or has not been started this bit is automatically cleared when txgspm is cleared. bit 2 txgval: timerx gate current state bit indicates the current state of the timerx gate that could be provided to tmrxh:tmrxl. unaffect ed by the timerx gate enable (tmrxge) bit. bit 1-0 txgss<1:0>: timerx gate source select bits 11 = comparator 2 output 10 = comparator 1 output 01 = tmr(x+1) to match pr(x+1) output ( 2 ) 00 = timer1 gate pin the watchdog timer oscillator is turned on if tmrxge = 1 , regardless of the state of tmrxon. note 1: programming the txgcon prior to txcon is recommended. 2: timer(x+1) will be timer4/6/8 for timerx (timer3/5/7), respectively. downloaded from: http:///
pic18f87k22 family ds39960d-page 214 ? 2009-2011 microchip technology inc. register 16-3: osccon2: osci llator control register 2 u-0 r-0 u-0 u-0 r/w-0 u-0 r-x r/w-0 soscrun s o s c g o mfiofs mfiosel bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 unimplemented: read as 0 bit 6 soscrun: sosc run status bit 1 = system clock comes from a secondary sosc 0 = system clock comes from an oscillator other than sosc bit 5-4 unimplemented: read as 0 bit 3 soscgo: oscillator start control bit 1 = oscillator is running even if no other sources are requesting it 0 = oscillator is shut off if no other sources are requesting it (when the sosc is selected to run from a digital clock input, rather than an external crystal, this bit has no effect.) bit 2 unimplemented: read as 0 bit 1 mfiofs: mf-intosc frequency stable bit 1 = mf-intosc is stable 0 = mf-intosc is not stable bit 0 mfiosel: mf-intosc select bit 1 = mf-intosc is used in place of hf-intosc frequencies of 500 khz, 250 khz and 31.25 khz 0 = mf-intosc is not used downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 215 pic18f87k22 family 16.2 timer3/5/7 operation timer3, timer5 and timer7 can operate in these modes: timer synchronous counter asynchronous counter timer with gated control the operating mode is determined by the clock select bits, tmrxcsx (txcon<7:6>). when the tmrxcsx bits are cleared (= 00 ), timer3/5/7 increments on every inter- nal instruction cycle (f osc /4). when tmrxcsx = 01 , the timer3/5/7 clock source is the system clock (f osc ), and when it is 10 , timer3/5/7 works as a counter from the external clock from the txcki pin (on the rising edge after the first falling edge) or the sosc oscillator. figure 16-1: timer3/5 /7 block diagram tmr3h tmr3l t3sync t3ckps<1:0> prescaler 1, 2, 4, 8 01 synchronized clock input 2 set flag bit tmr3if on overflow tmr3 (2) tmr3on note 1: st buffer is high-speed type when using t3cki. 2: timer3 registers increment on rising edge. 3: synchronization does not operate while in sleep. 4: the output of sosc is determined by the soscsel<1:0> configuration bits. t3g sosc f osc /4 internal clock sosco/sclki sosci 10 t3cki tmr3cs<1:0> (1) synchronize (3) det sleep input tmr3ge 01 00 01 10 11 from tmr4 from comparator 1 t3gpol d q ck q 01 t3gval t3gtm single pulse acq. control t3gspm t3ggo/t3done t3gss<1:0> en out (4) 1000 01 f osc internal clock from comparator 2 output match pr4 r d en q q1 rd t3gcon data bus det interrupt tmr3gif set t3clk f osc /2 internal clock d en q t3g_in tmr3on output t1con.soscen t3con.soscen soscgo scs<1:0> = 01 downloaded from: http:///
pic18f87k22 family ds39960d-page 216 ? 2009-2011 microchip technology inc. 16.3 timer3/5/7 16-bit read/write mode timer3/5/7 can be configured for 16-bit reads and writes (see figure 16.3 ). when the rd16 control bit (txcon<1>) is set, the address for tmrxh is mapped to a buffer register for the high byte of timer3/5/7. a read from tmrxl will load the contents of the high byte of timer3/5/7 into the timerx high byte buffer register. this provides users with the ability to accurately read all 16 bits of timer3/5/7 without having to determine whether a read of the high byte, followed by a read of the low byte, has become invalid due to a rollover between reads. a write to the high byte of timer3/5/7 must also take place through the tmrxh buffer register. the timer3/ 5/7 high byte is updated with the contents of tmrxh when a write occurs to tmrxl. this allows users to write all 16 bits to both the high and low bytes of timer3/5/7 at once. the high byte of timer3/5/7 is not directly readable or writable in this mode. all reads and writes must take place through the timerx high byte buffer register. writes to tmrxh do not clear the timer3/5/7 prescaler. the prescaler is only cleared on writes to tmrxl. 16.4 using the sosc oscillator as the timer3/5/7 clock source the sosc internal oscillator may be used as the clock source for timer3/5/7. the sosc oscillator is enabled by any p eripheral that requests it. there are eight ways the sosc can be enabled: if the sosc is selected as the source by any of the odd timers, which is done by each respective soscen bit (txcon<3>), if the sosc is selected as the rtcc source by the rtcosc configuration bit (config3l<1>), if the sosc is selected as the cpu clock source by the scs bits (osccon<1:0>) or if the soscgo bit is set (osccon2<3>). the soscgo bit is used to warm up the sosc so that it is ready before any peripheral requests it. to use it as the timer3/5/7 clock source, the tmrxcs bit must also be set. as previously noted, this also configures timer3/5/7 to increment on every rising edge of the oscillator source. the sosc oscillator is described in section 14.5 sosc oscillator . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 217 pic18f87k22 family 16.5 timer3/5/7 gates timer3/5/7 can be configured to count freely or the count can be enabled and disabled using the timer3/5/7 gate circuitry. this is also referred to as the timer3/5/7 gate count enable. the timer3/5/7 gate can also be driven by multiple selectable sources. 16.5.1 timer3/5/7 gate count enable the timerx gate enable mode is enabled by setting the tmrxge bit (txgcon<7>). the polarity of the timerx gate enable mode is configured using the txgpol bit (txgcon<6>). when timerx gate enable mode is enabled, timer3/5/7 will increment on the rising edge of the timer3/5/7 clock source. when timerx gate enable mode is disabled, no incrementing will occur and timer3/5/7 will hold the current count. see figure 16-2 for timing details. table 16-1: timer3/5/7 gate enable selections figure 16-2: timer3/5/7 gate count enable mode txclk ( ? ) txgpol (txgcon<6>) txg pin timerx operation ? 00 counts ? 01 holds count ? 10 holds count ? 11 counts ? the clock on which tmr3/5/7 is running. for more information, see txclk in figure 16-1 . tmrxge txgpol txg_in txcki txgval timer3/5/7 n n + 1 n + 2 n + 3 n + 4 downloaded from: http:///
pic18f87k22 family ds39960d-page 218 ? 2009-2011 microchip technology inc. 16.5.2 timer3/5/7 gate source selection the timer3/5/7 gate source can be selected from one of four different sources. source selection is controlled by the txgss<1:0> bits (txgcon<1:0>). the polarity for each available source is also selectable and is controlled by the txgpol bit (txgcon <6>). table 16-2: timer3/5/7 gate sources 16.5.2.1 txg pin gate operation the txg pin is one source for timer3/5/7 gate control. it can be used to supply an external source to the timerx gate circuitry. 16.5.2.2 timer4/6/8 match gate operation the tmr(x+1) register will increment until it matches the value in the pr(x+1) register. on the very next increment cycle, tmr2 will be reset to 00h. when this reset occurs, a low-to-high pulse will automatically be gener- ated and internally supplied to the timerx gate circuitry. the pulse will remain high for one instruction cycle and will return back to a low state until the next match. depending on txgpol, timerx increments differently when tmr(x+1) matches pr(x+1). when txgpol = 1 , timerx increments for a single instruction cycle following a tmr(x+1) match with pr(x+1). when txgpol = 0 , timerx increments continuously, except for the cycle following the match, when the gate signal goes from low-to-high. 16.5.2.3 comparator 1 output gate operation the output of comparator 1 can be internally supplied to the timerx gate circuitry. after setting up comparator 1 with the cm1con register, timerx will increment depending on the transitions of the cmp1out (cmstat<5>) bit. 16.5.2.4 comparator 2 output gate operation the output of comparator 2 can be internally supplied to the timerx gate circuitry. after setting up comparator 2 with the cm2con register, timerx will increment depending on the transitions of the cmp2out (cmstat<6>) bit. 16.5.3 timer3/5/7 gate toggle mode when timer3/5/7 gate toggle mode is enabled, it is possible to measure the full cycle length of a timer3/5/7 gate signal, as opposed to the duration of a single level pulse. the timerx gate source is routed through a flip-flop that changes state on every incrementing edge of the signal. (for timing details, see figure 16-3 .) the txgval bit will indicate when the toggled mode is active and the timer is counting. timer3/5/7 gate toggle mode is enabled by setting the txgtm bit (txgcon<5>). when the txgtm bit is cleared, the flip-flop is cleared and held clear. this is necessary in order to control which edge is measured. figure 16-3: timer3/5/7 gate toggle mode txgss<1:0> timerx gate source 00 timerx gate pin 01 tmr(x+1) to match pr(x+1) (tmr(x+1) increments to match pr(x+1)) 10 comparator 1 output (comparator logic high output) 11 comparator 2 output (comparator logic high output) tmrxge txgpol txgtm txg_in txcki txgval timer3/5/7 n n + 1 n + 2 n + 3 n + 4 n + 5 n + 6 n + 7 n + 8 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 219 pic18f87k22 family 16.5.4 timer3/5/7 gate single pulse mode when timer3/5/7 gate single pulse mode is enabled, it is possible to capture a single pulse gate event. timer3/5/7 gate single pulse mode is first enabled by setting the txgspm bit (txgcon<4>). next, the txggo/txdone bit (txgcon<3>) must be set. the timer3/5/7 will be fully enabled on the next incre- menting edge. on the next trailing edge of the pulse, the txggo/txdone bit will automatically be cleared. no other gate events will be allowed to increment timer3/5/7 until the txggo/txdone bit is once again set in software. clearing the txgspm bit also will clear the txggo/ txdone bit. (for timing details, see figure 16-4 .) simultaneously enabling the toggle mode and the single pulse mode will permit both sections to work together. this allows the cycle times on the timer3/5/7 gate source to be measured. (for timing details, see figure 16-5 .) figure 16-4: timer3/5/7 gate single pulse mode tmrxge txgpol txg_in txcki txgval timer3/5/7 n n + 1 n + 2 txgspm txggo/ txdone set by software cleared by hardware on falling edge of txgval set by hardware on falling edge of txgval cleared by software cleared by software tmrxgif counting enabled on rising edge of txg downloaded from: http:///
pic18f87k22 family ds39960d-page 220 ? 2009-2011 microchip technology inc. figure 16-5: timer3/5/7 gate single pulse and toggle combined mode 16.5.5 timer3/5/7 gate value status when timer3/5/7 gate value status is utilized, it is possible to read the most current level of the gate con- trol value. the value is stored in the txgval bit (txgcon<2>). the txgval bit is valid even when the timer3/5/7 gate is not enabled (tmrxge bit is cleared). 16.5.6 timer3/5/7 gate event interrupt when the timer3/5/7 gate event interrupt is enabled, it is possible to generate an interrupt upon the comple- tion of a gate event. when the falling edge of txgval occurs, the tmrxgif flag bit in the pirx register will be set. if the tmrxgie bit in the piex register is set, then an interrupt will be recognized. the tmrxgif flag bit operates even when the timer3/5/7 gate is not enabled (tmrxge bit is cleared). tmrxge txgpol txg_in txcki txgval timer3/5/7 n n + 1 n + 2 txgspm txggo/ txdone set by software cleared by hardware on falling edge of txgval set by hardware on falling edge of txgval cleared by software cleared by software tmrxgif txgtm counting enabled on rising edge of txg n + 4 n + 3 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 221 pic18f87k22 family 16.6 timer3/5/7 interrupt the tmrx register pair (tmrxh:tmrxl) increments from 0000h to ffffh and overflows to 0000h. the timerx interrupt, if enabled, is generated on overflow and is latched in the interrupt flag bit, tmrxif. table 16-3 gives each modules flag bit. this interrupt can be enabled or disabled by setting or clearing the tmrxie bit, respectively. table 16-4 gives each modules enable bit. 16.7 resetting timer3/5/7 using the eccp special event trigger if the eccp modules are configured to use timerx and to generate a special event trigger in compare mode (ccpxm<3:0> = 1011 ), this signal will reset timerx. the trigger from eccp2 will also start an a/d conversion if the a/d module is enabled. (for more information, see section 20.3.4 special event trigger .) the module must be configured as either a timer or synchronous counter to take advantage of this feature. when used this way, the ccprxh:ccprxl register pair effectively becomes a period register for timerx. if timerx is running in asynchronous counter mode, the reset operation may not work. in the event that a write to timerx coincides with a special event trigger from an eccp module, the write will take precedence. table 16-3: timer3/5/7 interrupt flag bits timer module flag bit 3 pir2<1> 5 pir5<1> 7 pir5<3> table 16-4: timer3/5/7 interrupt enable bits timer module flag bit 3 pie2<1> 5 pie5<1> 7 pie5<3> note: the special event triggers from the eccpx module will only clear the tmr3 registers content, but not set the tmr3if interrupt flag bit (pir1<0>). note: the ccp and eccp modules use timers, 1 through 8, for some modes. the assign- ment of a particular timer to a ccp/eccp module is determined by the timer to ccp enable bits in the ccptmrsx registers. for more details, see register 19-2 , register 19-3 and register 20-2 downloaded from: http:///
pic18f87k22 family ds39960d-page 222 ? 2009-2011 microchip technology inc. table 16-5: registers associated with timer3/5/7 as a timer/counter name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir5 tmr7gif ( 1 ) tmr12if ( 1 ) tmr10if ( 1 ) tmr8if tmr7if ( 1 ) tmr6if tmr5if tmr4if ipr5 tmr7gip ( 1 ) tmr12ip ( 1 ) tmr10ip ( 1 ) tmr8ip tmr7ip ( 1 ) tmr6ip tmr5ip tmr4ip pie5 tmr7gie ( 1 ) tmr12ie ( 1 ) tmr10ie ( 1 ) tmr8ie tmr7ie ( 1 ) tmr6ie tmr5ie tmr4ie pie3 tmr5gie rc2ie tx2ie ctmuie ccp2ie ccp1ie rtccie ipr3 tmr5gip rc2ip tx2ip ctmuip ccp2ip ccp1ip rtccip pir3 tmr5gif rc2if tx2if ctmuif ccp2if ccp1if rtccif pie2 oscfie ssp2ie bcl2ie bcl1ie hlvdie tmr3ie tmr3gie pir2 oscfif ssp2if bcl2if bcl1if hlvdif tmr3if tmr3gif ipr2 oscfip ssp2ip bcl2ip bcl1ip hlvdip tmr3ip tmr3gip tmr3h timer3 register high byte tmr3l timer3 register low byte t3gcon tmr3ge t3gpol t3gtm t3gspm t3ggo/ t3done t3gval t3gss1 t3gss0 t3con tmr3cs1 tmr3cs0 t3ckps1 t3ckps0 soscen t3sync rd16 tmr3on tmr5h timer5 register high byte tmr5l timer5 register low byte t5gcon tmr5ge t5gpol t5gtm t5gspm t5ggo/ t5done t5gval t5gss1 t5gss0 t5con tmr5cs1 tmr5cs0 t5ckps1 t5ckps0 soscen t5sync rd16 tmr5on tmr7h ( 1 ) timer7 register high byte tmr7l ( 1 ) timer7 register low byte t7gcon ( 1 ) tmr7ge t7gpol t7gtm t7gspm t7ggo/ t7done t7gval t7gss1 t7gss0 t7con ( 1 ) tmr7cs1 tmr7cs0 t7ckps1 t7ckps0 soscen t7sync rd16 tmr7on osccon2 soscrun s o s c g o mfiofs mfiosel pmd1 pspmd ctmumd rtccmd tmr4md tmr3md tmr2md tmr1md embmd pmd2 tmr10md ( 1 ) tmr8md tmr7md ( 1 ) tmr6md tmr5md cmp3md cmp2md cmp2md legend: = unimplemented, read as 0 . shaded cells are not used by the timer3/5/7 module. note 1: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 223 pic18f87k22 family 17.0 timer4/6/8/10/12 modules the timer4/6/8/10/12 timer modules have the following features: eight-bit timer register (tmrx) eight-bit period register (prx) readable and writable (all registers) software programmable prescaler (1:1, 1:4, 1:16) software programmable postscaler (1:1 to 1:16) interrupt on tmrx match of prx timer10 and timer12 are unimplemented for devices with a program memory of 32 kbytes (pic18fx5k22). the timer4/6/8/10/12 modules have a control register, which is shown in register 17-1 . timer4/6/8/10/12 can be shut off by clearing control bit, tmrxon (txcon<2>), to minimize power consumption. the prescaler and post- scaler selection of timer4/6/8/10/12 are also controlled by this register. figure 17-1 is a simplified block diagram of the timer4/6/8/10/12 modules. 17.1 timer4/6/8/10/12 operation timer4/6/8/10/12 can be used as the pwm time base for the pwm mode of the eccp modules. the tmrx registers are readable and writable, and are cleared on any device reset. the input clock (f osc /4) has a prescale option of 1:1, 1:4 or 1:16, selected by control bits, txckps<1:0> (txcon<1:0>). the match output of tmrx goes through a four-bit postscaler (that gives a 1:1 to 1:16 inclusive scaling) to generate a tmrx interrupt, latched in the flag bit, tmrxif. tab l e 1 7- 1 shows each modules flag bit. the interrupt can be enabled or disabled by setting or clearing the timerx interrupt enable bit (tmrxie), shown in tab l e 1 7- 2 . the prescaler and postscaler counters are cleared when any of the following occurs: a write to the tmrx register a write to the txcon register any device reset C power-on reset (por), mclr reset, watchdog timer reset (wdtr) or brown-out reset (bor) a tmrx is not cleared when a txcon is written. note: throughout this section, generic references are used for register and bit names that are the same, except for an x variable that indicates the items association with the timer4, timer6, timer8, timer10 or timer12 module. for example, the control register is named txcon and refers to t4con, t6con, t8con, t10con and t12con. table 17-1: timer4/6/8/10/12 flag bits timer module flag bit pir5 timer module flag bit pir5 401 05 621 26 84 table 17-2: timer4/6/8/10/12 interrupt enable bits timer module flag bit pie5 timer module flag bit pie5 401 05 621 26 84 note: the ccp and eccp modules use timers, 1 through 8, for some modes. the assign- ment of a particular timer to a ccp/eccp module is determined by the timer to ccp enable bits in the ccptmrsx registers. for more details, see register 19-2 , register 19-3 and register 20-2 . downloaded from: http:///
pic18f87k22 family ds39960d-page 224 ? 2009-2011 microchip technology inc. 17.2 timer4/6/8/10/12 interrupt the timer4/6/8/10/12 modules have eight-bit period registers, prx, that are both readable and writable. timer4/6/8/10/12 increment from 00h until they match pr4/6/8/10/12 and then reset to 00h on the next increment cycle. the prx registers are initialized to ffh upon reset. 17.3 output of tmrx the outputs of tmrx (before the postscaler) are used only as a pwm time base for the eccp modules. they are not used as baud rate clocks for the mssp modules as is the timer2 output. figure 17-1: timer4 block diagram register 17-1: txcon: ti merx control register u-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 txoutps3 txoutps2 txoutps1 txoutps0 tmrxon txckps1 txckps0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 unimplemented: read as 0 bit 6-3 txoutps<3:0>: timerx output postscale select bits 0000 = 1:1 postscale 0001 = 1:2 postscale 1111 = 1:16 postscale bit 2 tmrxon : timerx on bit 1 = timerx is on 0 = timerx is off bit 1-0 txckps<1:0>: timerx clock prescale select bits 00 = prescaler is 1 01 = prescaler is 4 1x = prescaler is 16 comparator tmrx output tmrx postscaler prescaler prx 2 f osc /4 1:1 to 1:16 1:1, 1:4, 1:16 4 txoutps<3:0> txckps<1:0> set tmrxif internal data bus 8 reset tmrx/prx 8 8 (to pwm) match downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 225 pic18f87k22 family table 17-3: registers associated with timer4/6/8/10/12 as a timer/counter name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif ipr5 tmr7gip ( 1 ) tmr12ip ( 1 ) tmr10ip ( 1 ) tmr8ip tmr7ip ( 1 ) tmr6ip tmr5ip tmr4ip pir5 tmr7gif ( 1 ) tmr12if ( 1 ) tmr10if ( 1 ) tmr8if tmr7if ( 1 ) tmr6if tmr5if tmr4if pie5 tmr7gie ( 1 ) tmr12ie ( 1 ) tmr10ie ( 1 ) tmr8ie tmr7ie ( 1 ) tmr6ie tmr5ie tmr4ie tmr4 timer4 register t4con t4outps3 t4outps2 t4outps1 t4 outps0 tmr4on t4ckps1 t4ckps0 pr4 timer4 period register tmr6 timer6 register t6con t6outps3 t6outps2 t6outps1 t6 outps0 tmr6on t6ckps1 t6ckps0 pr6 timer6 period register tmr8 timer8 register t8con t8outps3 t8outps2 t8outps1 t8 outps0 tmr8on t8ckps1 t8ckps0 pr8 timer8 period register tmr10 ( 1 ) timer10 register t10con ( 1 ) t10outps3 t10outps2 t10outps1 t10outps0 tmr10on t10ckps1 t10ckps0 pr10 ( 1 ) timer10 period register tmr12 ( 1 ) timer12 register t12con ( 1 ) t12outps3 t12outps2 t12outps1 t12outps0 tmr12on t12ckps1 t12ckps0 pr12 ( 1 ) timer12 period register pmd1 pspmd ctmumd rtccmd tmr4md tmr3md tmr2md tmr1md embmd pmd2 tmr10md ( 1 ) tmr8md tmr7md ( 1 ) tmr6md tmr5md cmp3md cmp2md cmp2md pmd3 ccp10md ( 1 ) ccp9md ( 1 ) ccp8md ccp7md ccp6md ccp5md ccp4md tmr12md ( 1 ) legend: = unimplemented, read as 0 . shaded cells are not used by the timer4/6/8/10/12 module. note 1: unimplemented on devices with a program memory of 32 kbytes (pic18fx5k22). downloaded from: http:///
pic18f87k22 family ds39960d-page 226 ? 2009-2011 microchip technology inc. notes: downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 227 pic18f87k22 family 18.0 real-time clock and calendar (rtcc) the key features of the real-time clock and calendar (rtcc) module are: time: hours, minutes and seconds twenty-four hour format (military time) calendar: weekday, date, month and year alarm configurable year range: 2000 to 2099 leap year correction bcd format for compact firmware optimized for low-power operation user calibration with auto-adjust calibration range: ? 2.64 seconds error per month requirements: external 32.768 khz clock crystal alarm pulse or seconds clock output on rtcc pin the rtcc module is intended for applications where accurate time must be maintained for extended period with minimum to no intervention from the cpu. the module is optimized for low-power usage in order to provide extended battery life while keeping track of time. the module is a 100-year clock and calendar with auto- matic leap year detection. the range of the clock is from 00:00:00 (midnight) on january 1, 2000 to 23:59:59 on december 31, 2099. hours are measured in 24-hour (military time) format. the clock provides a granularity of one second with half-second visibility to the user. figure 18-1: rtcc block diagram rtcc prescalers rtcc timer comparator compare registers repeat counter year mthdy wkdyhr minsec almthdy alwdhr alminsec with masks rtcc interrupt logic rtccfg alrmrpt alarm event 0.5s rtcc clock domain alarm pulse rtcc interrupt cpu clock domain rtcvalx alrmvalx rtcc pin rtcoe 32.768 khz input from sosc oscillator internal rc (lf-intosc) downloaded from: http:///
pic18f87k22 family ds39960d-page 228 ? 2009-2011 microchip technology inc. 18.1 rtcc module registers the rtcc module registers are divided into the following categories: rtcc control registers rtccfg rtccal padcfg1 alrmcfg alrmrpt rtcc value registers rtcvalh rtcvall both registers access the following registers: - year -month -day - weekday -hour - minute - second alarm value registers alrmvalh alrmvall both registers access the following registers: - alrmmnth -alrmday -alrmwd -alrmhr - alrmmin - alrmsec note: the rtcvalh and rtcvall registers can be accessed through rtcrpt<1:0> (rtccfg<1:0>). alrmvalh and alrmvall can be accessed through alrmptr<1:0> (alrmcfg<1:0>). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 229 pic18f87k22 family 18.1.1 rtcc control registers register 18-1: rtccfg: rtcc configuration register ( 1 ) r/w-0 u-0 r/w-0 r-0 r-0 r/w-0 r/w-0 r/w-0 rtcen ( 2 ) r t c w r e n ( 4 ) rtcsync halfsec ( 3 ) rtcoe rtcptr1 rtcptr0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 rtcen: rtcc enable bit ( 2 ) 1 = rtcc module is enabled 0 = rtcc module is disabled bit 6 unimplemented: read as 0 bit 5 rtcwren: rtcc value registers write enable bit ( 4 ) 1 = rtcvalh and rtcvall registers can be written to by the user 0 = rtcvalh and rtcvall registers are locked out from being written to by the user bit 4 rtcsync: rtcc value registers read synchronization bit 1 = rtcvalh, rtcvall and alrmrpt registers can change while reading if a rollover ripple results in an invalid data read. if the register is read twice and results in the same data, the data can be assumed to be valid. 0 = rtcvalh, rtcvall and alcfgrpt registers can be read without concern over a rollover ripple bit 3 halfsec: half-second status bit ( 3 ) 1 = second half period of a second 0 = first half period of a second bit 2 rtcoe: rtcc output enable bit 1 = rtcc clock output is enabled 0 = rtcc clock output is disabled bit 1-0 rtcptr<1:0>: rtcc value register window pointer bits points to the corresponding rtcc value registers when reading the rtcvalh and rtcvall registers. the rtcptr<1:0> value decrements on every read or write of rtcvalh<15:8> until it reaches 00 . rtcvalh: 00 = minutes 01 = weekday 10 = month 11 = reserved rtcvall: 00 = seconds 01 = hours 10 = day 11 = year note 1: the rtccfg register is only affected by a por. 2: a write to the rtcen bit is only allowed when rtcwren = 1 . 3: this bit is read-only; it is cleared to 0 on a write to the lower half of the minsec register. 4: rtcwren can only be written with the unlock sequence (see example 18-1 ). downloaded from: http:///
pic18f87k22 family ds39960d-page 230 ? 2009-2011 microchip technology inc. register 18-2: rtccal: rtcc calibration register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 cal7 cal6 cal5 cal4 cal3 cal2 cal1 cal0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-0 cal<7:0>: rtc drift calibration bits 01111111 = maximum positive adjustment. adds 508 rtc clock pulses every minute. .. . 00000001 = minimum positive adjustment. adds four rtc clock pulses every minute. 00000000 = no adjustment 11111111 = minimum negative adjustment. subtracts four rtc clock pulses every minute. .. . 10000000 = maximum negative adjustment. subtracts 512 rtc clock pulses every minute. register 18-3: padcfg1: pad configuration register r/w-0 r/w-0 r/w-0 u-0 u-0 r/w-0 r/w-0 u-0 rdpu repu rjpu ( 2 ) rtsecsel1 ( 1 ) rtsecsel0 ( 1 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 rdpu: portd pull-up enable bit 1 = portd pull-up resistors are enabled by individual port latch values 0 = all portd pull-up resistors are disabled bit 6 repu: porte pull-up enable bit 1 = porte pull-up resistors are enabled by individual port latch values 0 = all porte pull-up resistors are disabled bit 5 rjpu: portj pull-up enable bit ( 2 ) 1 = portj pull-up resistors are enabled by individual port latch values 0 = all portj pull-up resistors are disabled bit 2-1 rtsecsel<1:0>: rtcc seconds clock output select bits ( 1 ) 11 = reserved; do not use 10 = rtcc source clock is selected for the rtcc pin (pin can be lf-intosc or sosc, depending on the rtcosc (config3l<1>) bit setting) 01 = rtcc seconds clock is selected for the rtcc pin 00 = rtcc alarm pulse is selected for the rtcc pin bit 0 unimplemented: read as 0 note 1: to enable the actual rtcc output, the rtcoe (rtccfg<2>) bit must be set. 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 231 pic18f87k22 family register 18-4: alrmcfg: al arm configuration register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 alrmen chime amask3 amask2 amask1 amask0 alrmptr1 alrmptr0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 alrmen: alarm enable bit 1 = alarm is enabled (cleared automatically after an alarm event whenever arpt<7:0> = 00 and chime = 0 ) 0 = alarm is disabled bit 6 chime: chime enable bit 1 = chime is enabled; alrmptr<1:0> bits are allowed to roll over from 00h to ffh 0 = chime is disabled; alrmptr<1:0> bits stop once they reach 00h bit 5-2 amask<3:0>: alarm mask configuration bits 0000 = every half second 0001 = every second 0010 = every 10 seconds 0011 = every minute 0100 = every 10 minutes 0101 = every hour 0110 = once a day 0111 = once a week 1000 = once a month 1001 = once a year (except when configured for february 29 th , once every four years) 101x = reserved C do not use 11xx = reserved C do not use bit 1-0 alrmptr<1:0>: alarm value register window pointer bits points to the corresponding alarm value registers when reading the alrmvalh and alrmvall registers. the alrmptr<1:0> value decrements on every read or write of alrmvalh until it reaches 00 . alrmvalh: 00 = alrmmin 01 =alrmwd 10 =alrmmnth 11 = unimplemented alrmvall: 00 = alrmsec 01 =alrmhr 10 =alrmday 11 = unimplemented downloaded from: http:///
pic18f87k22 family ds39960d-page 232 ? 2009-2011 microchip technology inc. 18.1.2 rtcvalh and rtcvall register mappings register 18-5: alrmrpt: alarm repeat register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 arpt7 arpt6 arpt5 arpt4 arpt3 arpt2 arpt1 arpt0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-0 arpt<7:0>: alarm repeat counter value bits 11111111 = alarm will repeat 255 more times .. . 00000000 = alarm will not repeat the counter decrements on any alarm event. the counter is prevented from rolling over from 00h to ffh unless chime = 1 . register 18-6: reserved register u-0 u-0 u-0 u-0 u-0 u-0 u-0 u-0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-0 unimplemented: read as 0 register 18-7: year: year value register ( 1 ) r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x yrten3 yrten2 yrten1 yrten0 yrone3 yrone2 yrone1 yrone0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-4 yrten<3:0>: binary coded decimal value of years tens digit bits contains a value from 0 to 9. bit 3-0 yrone<3:0>: binary coded decimal value of years ones digit bits contains a value from 0 to 9. note 1: a write to the year register is only allowed when rtcwren = 1 . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 233 pic18f87k22 family register 18-8: month: month value register ( 1 ) u-0 u-0 u-0 r/w-x r/w-x r/w-x r/w-x r/w-x mthten0 mthone3 mthone2 mthone1 mthone0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-5 unimplemented: read as 0 bit 4 mthten0: binary coded decimal value of months tens digit bit contains a value of 0 or 1. bit 3-0 mthone<3:0>: binary coded decimal value of months ones digit bits contains a value from 0 to 9. note 1: a write to this register is only allowed when rtcwren = 1 . register 18-9: day: day value register ( 1 ) u-0 u-0 r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x dayten1 dayten0 dayone3 dayone2 dayone1 dayone0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-6 unimplemented: read as 0 bit 5-4 dayten<1:0>: binary coded decimal value of days tens digit bits contains a value from 0 to 3. bit 3-0 dayone<3:0>: binary coded decimal value of days ones digit bits contains a value from 0 to 9. note 1: a write to this register is only allowed when rtcwren = 1 . register 18-10: weekday: weekday value register ( 1 ) u-0 u-0 u-0 u-0 u-0 r/w-x r/w-x r/w-x wday2 wday1 wday0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-3 unimplemented: read as 0 bit 2-0 wday<2:0>: binary coded decimal value of weekday digit bits contains a value from 0 to 6. note 1: a write to this register is only allowed when rtcwren = 1 . downloaded from: http:///
pic18f87k22 family ds39960d-page 234 ? 2009-2011 microchip technology inc. register 18-11: hour: hour value register ( 1 ) u-0 u-0 r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x hrten1 hrten0 hrone3 hrone2 hrone1 hrone0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-6 unimplemented: read as 0 bit 5-4 hrten<1:0>: binary coded decimal value of hours tens digit bits contains a value from 0 to 2. bit 3-0 hrone<3:0>: binary coded decimal value of hours ones digit bits contains a value from 0 to 9. note 1: a write to this register is only allowed when rtcwren = 1 . register 18-12: minute: minute value register u-0 r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x minten2 minten1 minten0 minone3 minone2 minone1 minone0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 unimplemented: read as 0 bit 6-4 minten<2:0>: binary coded decimal value of minutes tens digit bits contains a value from 0 to 5. bit 3-0 minone<3:0>: binary coded decimal value of minutes ones digit bits contains a value from 0 to 9. register 18-13: second: second value register u-0 r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x secten2 secten1 secten0 secone3 secone2 secone1 secone0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 unimplemented: read as 0 bit 6-4 secten<2:0>: binary coded decimal value of seconds tens digit bits contains a value from 0 to 5. bit 3-0 secone<3:0>: binary coded decimal value of seconds ones digit bits contains a value from 0 to 9. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 235 pic18f87k22 family 18.1.3 alrmvalh and alrmvall register mappings register 18-14: alrmmnth: alarm month value register ( 1 ) u-0 u-0 u-0 r/w-x r/w-x r/w-x r/w-x r/w-x mthten0 mthone3 mthone2 mthone1 mthone0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-5 unimplemented: read as 0 bit 4 mthten0: binary coded decimal value of months tens digit bits contains a value of 0 or 1. bit 3-0 mthone<3:0>: binary coded decimal value of months ones digit bits contains a value from 0 to 9. note 1: a write to this register is only allowed when rtcwren = 1 . register 18-15: alrmday: alarm day value register ( 1 ) u-0 u-0 r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x dayten1 dayten0 dayone3 dayone2 dayone1 dayone0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-6 unimplemented: read as 0 bit 5-4 dayten<1:0>: binary coded decimal value of days tens digit bits contains a value from 0 to 3. bit 3-0 dayone<3:0>: binary coded decimal value of days ones digit bits contains a value from 0 to 9. note 1: a write to this register is only allowed when rtcwren = 1 . register 18-16: alrmwd: alarm weekday value register ( 1 ) u-0 u-0 u-0 u-0 u-0 r/w-x r/w-x r/w-x wday2 wday1 wday0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-3 unimplemented: read as 0 bit 2-0 wday<2:0>: binary coded decimal value of weekday digit bits contains a value from 0 to 6. note 1: a write to this register is only allowed when rtcwren = 1 . downloaded from: http:///
pic18f87k22 family ds39960d-page 236 ? 2009-2011 microchip technology inc. register 18-17: alrmhr: alarm hours value register ( 1 ) u-0 u-0 r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x hrten1 hrten0 hrone3 hrone2 hrone1 hrone0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-6 unimplemented: read as 0 bit 5-4 hrten<1:0>: binary coded decimal value of hours tens digit bits contains a value from 0 to 2. bit 3-0 hrone<3:0>: binary coded decimal value of hours ones digit bits contains a value from 0 to 9. note 1: a write to this register is only allowed when rtcwren = 1 . register 18-18: alrmmin: alarm minutes value register u-0 r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x minten2 minten1 minten0 minone3 minone2 minone1 minone0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 unimplemented: read as 0 bit 6-4 minten<2:0>: binary coded decimal value of minutes tens digit bits contains a value from 0 to 5. bit 3-0 minone<3:0>: binary coded decimal value of minutes ones digit bits contains a value from 0 to 9. register 18-19: alrmsec: alarm seconds value register u-0 r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x secten2 secten1 secten0 secone3 secone2 secone1 secone0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 unimplemented: read as 0 bit 6-4 secten<2:0>: binary coded decimal value of seconds tens digit bits contains a value from 0 to 5. bit 3-0 secone<3:0>: binary coded decimal value of seconds ones digit bits contains a value from 0 to 9. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 237 pic18f87k22 family 18.1.4 rtcen bit write rtcwren (rtccfg<5>) must be set before a write to rtcen can take place. any write to the rtcen bit, while rtcwren = 0 , will be ignored. like the rtcen bit, the rtcvalh and rtcvall registers can only be written to when rtcwren = 1 . a write to these registers, while rtcwren = 0 , will be ignored. 18.2 operation 18.2.1 register interface the register interface for the rtcc and alarm values is implemented using the binary coded decimal (bcd) format. this simplifies the firmware when using the module, as each of the digits is contained within its own 4-bit value (see figure 18-2 and figure 18-3 ). figure 18-2: timer digit format figure 18-3: alarm digit format 0-6 0-9 0-9 0-3 0-9 0-9 0-9 0-9 0-2 0-5 0-5 0/1 day of week year day hours (24-hour format) minutes seconds 1/2 second bit 0-1 0-9 month (binary format) 0-6 0-3 0-9 0-9 0-9 0-9 0-2 0-5 0-5 day of week day hours (24-hour format) minutes seconds 0-1 0-9 month downloaded from: http:///
pic18f87k22 family ds39960d-page 238 ? 2009-2011 microchip technology inc. 18.2.2 clock source as previously mentioned, the rtcc module is intended to be clocked by an external real-time clock (rtc) crystal, oscillating at 32.768 khz, but an internal oscillator can be used. the rtcc clock selection is decided by the rtcosc bit (config3l<0>). calibration of the crystal can be done through this module to yield an error of 3 seconds or less per month. (for further details, see section 18.2.9 calibration .) figure 18-4: clock source multiplexing 18.2.2.1 real-time clock enable the rtcc module can be clocked by an external, 32.768 khz crystal (sosc oscillator) or the lf-intosc oscillator, which can be selected in config3l<0>. if the external clock is used, the sosc oscillator should be enabled. if lf-intosc is providing the clock, the intosc clock can be brought out to the rtcc pin by the rtsecsel<1:0> bits (padcfg<2:1>). 18.2.3 digit carry rules this section explains which timer values are affected when there is a rollover: time of day: from 23:59:59 to 00:00:00 with a carry to the day field month: from 12/31 to 01/01 with a carry to the year field day of week: from 6 to 0 with no carry (see table 18-1 ) year carry: from 99 to 00; this also surpasses the use of the rtcc for the day-to-month rollover schedule, see table 18-2 . because the following values are in bcd format, the carry to the upper bcd digit occurs at the count of 10, not 16 (seconds, minutes, hours, weekday, days and months). table 18-1: day of week schedule table 18-2: day to month rollover schedule note 1: writing to the lower half of the minsec register resets all counters, allowing fraction of a second synchronization; clock prescaler is held in reset when rtcen = 0 . 32.768 khz xtal 1:16384 half second (1) half-second clock one second clock year month day day of week second hour:minute clock prescaler (1) from sosc internal rc rtccfg day of week sunday 0 monday 1 tuesday 2 wednesday 3 thursday 4 friday 5 saturday 6 month maximum day field 01 (january) 31 02 (february) 28 or 29 ( 1 ) 03 (march) 31 04 (april) 30 05 (may) 31 06 (june) 30 07 (july) 31 08 (august) 31 09 (september) 30 10 (october) 31 11 (november) 30 12 (december) 31 note 1: see section 18.2.4 leap year . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 239 pic18f87k22 family 18.2.4 leap year since the year range on the rtcc module is 2000 to 2099, the leap year calculation is determined by any year divisible by four in the above range. only february is affected in a leap year. february will have 29 days in a leap year and 28 days in any other year. 18.2.5 general functionality all timer registers containing a time value of seconds or greater are writable. the us er configures the time by writing the required year, month, day, hour, minutes and seconds to the timer registers, via register pointers. (see section 18.2.8 register mapping .) the timer uses the newly written values and proceeds with the count from the required starting point. the rtcc is enabled by setting the rtcen bit (rtccfg<7>). if enabled, while adjusting these registers, the timer still continues to increment. however, any time the minsec register is written to, both of the timer prescalers are reset to 0 . this allows fraction of a second synchronization. the timer registers are updated in the same cycle as the write instructions execution by the cpu. the user must ensure that when rtcen = 1 , the updated registers will not be incremented at the same time. this can be accomplished in several ways: by checking the rtcsync bit (rtccfg<4>) by checking the preceding digits from which a carry can occur by updating the registers immediately following the seconds pulse (or an alarm interrupt) the user has visibility to the half-second field of the counter. this value is read-only and can be reset only by writing to the lower half of the seconds register. 18.2.6 safety window for register reads and writes the rtcsync bit indicates a time window during which the rtcc clock domain registers can be safely read and written without concern about a rollover. when rtcsync = 0 , the registers can be safely accessed by the cpu. whether rtcsync = 1 or 0 , the user should employ a firmware solution to ensure that the data read did not fall on a rollover boundary, resulting in an invalid or partial read. this firmware solution would consist of reading each register twice and then comparing the two values. if the two values matched, then a rollover did not occur. 18.2.7 write lock in order to perform a write to any of the rtcc timer registers, the rtcwren bit (rtccfg<5>) must be set. to avoid accidental writes to the rtcc timer register, it is recommended that the rtcwren bit (rtccfg<5>) be kept clear when not writing to the register. for the rtcwren bit to be set, there is only one instruction cycle time window allowed between the 55h/aa sequence and the setting of rtcwren. for that reason, it is recommended that users follow the code example in example 18-1 . example 18-1: setting the rtcwren bit 18.2.8 register mapping to limit the register interface, the rtcc timer and alarm timer registers are accessed through corresponding register pointers. the rtcc value register window (rtcvalh and rtcvall) uses the rtcptrx bits (rtccfg<1:0>) to select the required timer register pair. by reading or writing to the rtcvalh register, the rtcc pointer value (rtcptr<1:0>) decrements by 1 until it reaches 00 . when 00 is reached, the minutes and seconds value is accessible through rtcvalh and rtcvall until the pointer value is manually changed. table 18-3: rtcvalh and rtcvall register mapping the alarm value register windows (alrmvalh and alrmvall) use the alrmptr bits (alrmcfg<1:0>) to select the desired alarm register pair. by reading or writing to the alrmvalh register, the alarm pointer value, alrmptr<1:0>, decrements by one until it reaches 00 . when it reaches 00 , the alrmmin and alrmsec values are accessible through alrmvalh and alrmvall until the pointer value is manually changed. movlw 0x55 movwf eecon2 movlw 0xaa movwf eecon2 bsf rtccfg,rtcwren rtcptr<1:0> rtcc value register window rtcvalh rtcvall 00 minutes seconds 01 weekday hours 10 month day 11 year downloaded from: http:///
pic18f87k22 family ds39960d-page 240 ? 2009-2011 microchip technology inc. table 18-4: alrmval register mapping 18.2.9 calibration the real-time crystal input can be calibrated using the periodic auto-adjust feature. when properly calibrated, the rtcc can provide an error of less than three seconds per month. to perform this calibration, find the number of error clock pulses and store the value into the lower half of the rtccal register. the eight-bit, signed value, loaded into rtccal, is multiplied by four and will be either added or subtracted from the rtcc timer, once every minute. to calibrate the rtcc module: 1. use another timer resource on the device to find the error of the 32.768 khz crystal. 2. convert the number of error clock pulses per minute (see equation 18-1 ). if the oscillator is faster than ideal (negative result from step 2), the rcfgcall register value needs to be negative. this causes the specified number of clock pulses to be subtracted from the timer counter, once every minute. if the oscillator is slower than ideal (positive result from step 2), the rcfgcall register value needs to be positive. this causes the specified number of clock pulses to be added to the timer counter, once every minute. 3. load the rtccal register with the correct value. writes to the rtccal register should occur only when the timer is turned off or immediately after the rising edge of the seconds pulse. 18.3 alarm the alarm features and characteristics are: configurable from half a second to one year enabled using the alrmen bit (alrmcfg<7>, register 18-4 ) offers one-time and repeat alarm options 18.3.1 configuring the alarm the alarm feature is enabled using the alrmen bit. this bit is cleared when an alarm is issued. the bit will not be cleared if the chime bit = 1 or if alrmrpt ? 0 . the interval selection of the alarm is configured through the alrmcfg bits (amask<3:0>); see figure 18-5 . these bits determine which, and how many, digits of the alarm must match the clock value for the alarm to occur. the alarm can also be configured to repeat based on a preconfigured interval. the number of times this occurs, after the alarm is enabled, is stored in the alrmrpt register. alrmptr<1:0> alarm value register window alrmvalh alrmvall 00 alrmmin alrmsec 01 alrmwd alrmhr 10 alrmmnth alrmday 11 equation 18-1: converting error clock pulses (ideal frequency (32,758) C measured frequency) * 60 = error clocks per minute note: in determining the crystals error value, it is the users responsibility to include the crystals initial error from drift due to temperature or crystal aging. note: while the alarm is enabled (alrmen = 1 ), changing any of the registers, other than the rtccal, alrmcfg and alrmrpt registers and the chime bit, can result in a false alarm event leading to a false alarm interrupt. to avoid this, only change the timer and alarm values while the alarm is disabled (alrmen = 0 ). it is recom- mended that the alrmcfg and alrmrpt registers and chime bit be changed when rtcsync = 0 . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 241 pic18f87k22 family figure 18-5: alarm mask settings when alrmcfg = 00 and the chime bit = 0 (alrmcfg<6>), the repeat function is disabled and only a single alarm will occur. the alarm can be repeated up to 255 times by loading the alrmrpt register with ffh. after each alarm is issued, the alrmrpt register is decremented by one. once the register has reached 00 , the alarm will be issued one last time. after the alarm is issued a last time, the alrmen bit is cleared automatically and the alarm is turned off. indefinite repetition of the alarm can occur if the chime bit = 1 . when chime = 1 , the alarm is not disabled when the alrmrpt register reaches 00 , but it rolls over to ff and continues counting indefinitely. 18.3.2 alarm interrupt at every alarm event, an interrupt is generated. addi- tionally, an alarm pulse output is provided that operates at half the frequency of the alarm. the alarm pulse output is completely synchronous with the rtcc clock and can be used as a trigger clock to other peripherals. this output is available on the rtcc pin. the output pulse is a clock with a 50% duty cycle and a frequency half that of the alarm event (see figure 18-6 ). the rtcc pin also can output the seconds clock. the user can select between the alarm pulse, generated by the rtcc module, or the seconds clock output. the rtsecsel<1:0> bits (padcfg1<2:1>) select between these two outputs: alarm pulse C rtsecsel<1:0> = 00 seconds clock C rtsecsel<1:0> = 01 note 1: annually, except when configured for february 29. s ss mss mm s s hh mm ss dh h m m s s dd hh mm ss mm d d h h mm s s day of the week month day hours minutes seconds alarm mask setting amask<3:0> 0000 C every half second 0001 C every second 0010 C every 10 seconds 0011 C every minute 0100 C every 10 minutes 0101 C every hour 0110 C every day 0111 C every week 1000 C every month 1001 C every year (1) downloaded from: http:///
pic18f87k22 family ds39960d-page 242 ? 2009-2011 microchip technology inc. figure 18-6: timer pulse generation 18.4 sleep mode the timer and alarm continue to operate while in sleep mode. the operation of the alarm is not affected by sleep, as an alarm event can always wake up the cpu. the idle mode does not affect the operation of the timer or alarm. 18.5 reset 18.5.1 device reset when a device reset occurs, the alrmrpt register is forced to its reset state, causing the alarm to be disabled (if enabled prior to the reset). if the rtcc was enabled, it will continue to operate when a basic device reset occurs. 18.5.2 power-on reset (por) the rtccfg and alrmrpt registers are reset only on a por. once the device exits the por state, the clock registers should be reloaded with the desired values. the timer prescaler values can be reset only by writing to the seconds register. no device reset can affect the prescalers. rtcen bit alrmen bit rtcc alarm event rtcc pin downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 243 pic18f87k22 family 18.6 register maps table 18-5 , tab l e 1 8- 6 and table 18-7 summarize the registers associated with the rtcc module. table 18-5: rtcc control registers file name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 rtccfg rtcen rtcwren rtcsync halfsec rtcoe rtcptr1 rtcptr0 rtccal cal7 cal6 cal5 cal4 cal3 cal2 cal1 cal0 padcfg1 rdpu repu rjpu ( 1 ) rtsecsel1 rtsecsel0 alrmcfg alrmen chime amask3 amask2 amask1 amask0 alrmptr1 alrmptr0 alrmrpt arpt7 arpt6 arpt5 arpt4 arpt3 arpt2 arpt1 arpt0 pmd1 pspmd ctmumd rtccmd tmr4md tmr3md tmr2md tmr1md embdm legend: = unimplemented, read as 0 . reset values are shown in hexadecimal for 80-pin devices. note 1: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . table 18-6: rtcc value registers file name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 rtcvalh rtcc value high register window based on rtcptr<1:0> rtcvall rtcc value low register window based on rtcptr<1:0> table 18-7: alarm value registers file name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 alrmvalh alarm value high register window based on alrmptr<1:0> alrmvall alarm value low register window based on alrmptr<1:0> downloaded from: http:///
pic18f87k22 family ds39960d-page 244 ? 2009-2011 microchip technology inc. notes: downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 245 pic18f87k22 family 19.0 capture/compare/pwm (ccp) modules pic18f87k22 family devices have seven ccp (capture/compare/pwm) modules, designated ccp4 through ccp10. all the modules implement standard capture, compare and pulse-width modulation (pwm) modes. each ccp module contains a 16-bit register that can operate as a 16-bit capture register, a 16-bit compare register or a pwm master/slave duty cycle register. for the sake of clarity, all ccp module operation in the following sections is described with respect to ccp4, but is equally applicable to ccp5 through ccp10. note: throughout this section, generic references are used for register and bit names that are the same, except for an x variable that indicates the items association with the specific ccp module. for example, the control register is named ccpxcon and refers to ccp4con through ccp10con. note: the ccp9 and ccp10 modules are disabled on the devices with 32 kbytes of program memory (pic18fx5k22). register 19-1: ccpxcon: ccpx contro l register (ccp4-ccp10 modules) ( 1 ) r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 pxm1 pxm0 dcxb1 dcxb0 ccpxm3 ( 2 ) ccpxm2 ( 2 ) ccpxm1 ( 2 ) ccpxm0 ( 2 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-6 pxm<1:0>: pwm output configuration bits if ccpxm<3:2> = 00 , 01 , 10 : xx = pxa is assigned as a capture/compare input/ output; pxb, pxc and pxd are assigned as port pins if ccpxm<3:2> = 11 : 00 = single output: pxa, pxb, pxc and pxd are controlled by steering 01 = full-bridge output forward: pxd is modulated; pxa is active; pxb, pxc are inactive 10 = half-bridge output: pxa, pxb are modulated with dead-band control; pxc and pxd are assigned as port pins 11 = full-bridge output reverse: pxb is modulated; pxc is active; pxa and pxd are inactive bit 5-4 dcxb<1:0>: pwm duty cycle bit 1 and bit 0 for ccpx module capture mode: unused. compare mode: unused. pwm mode: these bits are the two least significant bits (bit 1 and bit 0) of the 10-bit pwm duty cycle. the eight most significant bits (dcx<9:2>) of the duty cycle are found in ccprxl. note 1: the ccp9 and ccp10 modules are not available on devices with 32 kbytes of program memory (pic18fx5k22). 2: ccpxm<3:0> = 1011 will only reset the timer and not start an a/d conversion on ccpx match. downloaded from: http:///
pic18f87k22 family ds39960d-page 246 ? 2009-2011 microchip technology inc. bit 3-0 ccpxm<3:0> : ccpx module mode select bits ( 2 ) 0000 = capture/compare/pwm disabled (resets ccpx module) 0001 = reserved 0010 = compare mode, toggle output on match (ccpxif bit is set) 0011 = reserved 0100 = capture mode: every falling edge 0101 = capture mode: every rising edge 0110 = capture mode: every 4th rising edge 0111 = capture mode: every 16th rising edge 1000 = compare mode: initialize ccpx pin low; on compar e match, force ccpx pin high (ccpxif bit is set) 1001 = compare mode: initialize ccpx pin high; on compare match, force ccpx pin low (ccpxif bit is set) 1010 = compare mode: generate software interrupt on compare match (ccpxif bit is set, ccpx pin reflects i/o state) 1011 = compare mode: special event trigger; reset timer on ccpx match (ccpxif bit is set) 11xx =pwm mode register 19-2: ccptmrs1: ccp timer select register 1 r/w-0 r/w-0 u-0 r/w-0 u-0 r/w-0 r/w-0 r/w-0 c7tsel1 c7tsel0 c6tsel0 c5tsel0 c4tsel1 c4tsel0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-6 c7tsel<1:0>: ccp7 timer selection bits 00 = ccp7 is based off of tmr1/tmr2 01 = ccp7 is based off of tmr5/tmr4 10 = ccp7 is based off of tmr5/tmr6 11 = ccp7 is based off of tmr5/tmr8 bit 5 unimplemented: read as 0 bit 4 c6tsel0: ccp6 timer selection bit 0 = ccp6 is based off of tmr1/tmr2 1 = ccp6 is based off of tmr5/tmr2 bit 3 unimplemented: read as 0 bit 2 c5tsel0: ccp5 timer selection bit 0 = ccp5 is based off of tmr1/tmr2 1 = ccp5 is based off of tmr5/tmr4 bit 1-0 c4tsel<1:0>: ccp4 timer selection bits 00 = ccp4 is based off of tmr1/tmr2 01 = ccp4 is based off of tmr3/tmr4 10 = ccp4 is based off of tmr3/tmr6 11 = reserved; do not use register 19-1: ccpxcon: ccpx contro l register (ccp4-ccp10 modules) ( 1 ) note 1: the ccp9 and ccp10 modules are not available on devices with 32 kbytes of program memory (pic18fx5k22). 2: ccpxm<3:0> = 1011 will only reset the timer and not start an a/d conversion on ccpx match. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 247 pic18f87k22 family register 19-3: ccptmrs2: ccp timer select register 2 u-0 u-0 u-0 r/w-0 u-0 r/w-0 r/w-0 r/w-0 c10tsel0 ( 1 ) c9tsel0 ( 1 ) c8tsel1 c8tsel0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-5 unimplemented: read as 0 bit 4 c10tsel0: ccp10 timer selection bit ( 1 ) 0 = ccp10 is based off of tmr1/tmr2 1 = ccp10 is based off of tmr7/tmr2 bit 3 unimplemented: read as 0 bit 2 c9tsel0: ccp9 timer selection bit ( 1 ) 0 = ccp9 is based off of tmr1/tmr2 1 = ccp9 is based off of tmr7/tmr4 bit 1-0 c8tsel<1:0>: ccp8 timer selection bits on non 32-byte device variants: 00 = ccp8 is based off of tmr1/tmr2 01 = ccp8 is based off of tmr7/tmr4 10 = ccp8 is based off of tmr7/tmr6 11 = reserved; do not use on 32- byte device variants (pic18f65k22 and pic18f85k22): 00 = ccp8 is based off of tmr1/tmr2 01 = ccp8 is based off of tmr1/tmr4 10 = ccp8 is based off of tmr1/tmr6 11 = reserved; do not use note 1: this bit is unimplemented and reads as 0 on devices with 32 kbytes of program memory (pic18fx5k22). downloaded from: http:///
pic18f87k22 family ds39960d-page 248 ? 2009-2011 microchip technology inc. register 19-4: ccprxl: ccpx period low byte register r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x ccprxl7 ccprxl6 ccprxl5 ccprxl4 ccprxl3 ccprxl2 ccprxl1 ccprxl0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-0 ccprxl<7:0>: ccpx period register low byte bits capture mode: capture register low byte compare mode: compare register low byte pwm mode: duty cycle register register 19-5: ccprxh: ccpx period high byte register r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x ccprxh7 ccprxh6 ccprxh5 ccprxh4 ccprxh3 ccprxh2 ccprxh1 ccprxh0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-0 ccprxh<7:0>: ccpx period register high byte bits capture mode: capture register high byte compare mode: compare register high byte pwm mode: duty cycle buffer register downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 249 pic18f87k22 family 19.1 ccp module configuration each capture/compare/pwm module is associated with a control register (generically, ccpxcon) and a data register (ccprx). the data register, in turn, is comprised of two 8-bit registers: ccprxl (low byte) and ccprxh (high byte). all registers are both readable and writable. 19.1.1 ccp modules and timer resources the ccp modules utilize timers, 1 through 8, which vary with the selected mode. various timers are avail- able to the ccp modules in capture, compare or pwm modes, as shown in table 19-1 . table 19-1: ccp mode C timer resource the assignment of a particular timer to a module is determined by the timer to ccp enable bits in the ccptmrsx registers (see register 19-2 and register 19-3 ). all of the modules may be active at once and may share the same timer resource if they are configured to operate in the same mode (capture/compare or pwm) at the same time. the ccptmrs1 register selects the timers for ccp modules, 7, 6, 5 and 4, and the ccptmrs2 register selects the timers for ccp modules, 10, 9 and 8. the possible configurations are shown in ta b l e 1 9 - 2 and table 19-3 . table 19-2: timer assignments for ccp modules 4, 5, 6 and 7 table 19-3: timer assignments for ccp modules 8, 9 and 10 ccp mode timer resource capture timer1, timer3, timer 5 or timer7 compare pwm timer2, timer4, timer 6 or timer8 ccptmrs1 register ccp4 ccp5 ccp6 ccp7 c4tsel <1:0> capture/ compare mode pwm mode c5tsel0 capture/ compare mode pwm mode c6tsel0 capture/ compare mode pwm mode c7tsel <1:0> capture/ compare mode pwm mode 00 tmr1 tmr2 0 tmr1 tmr2 0 tmr1 tmr2 00 tmr1 tmr2 01 tmr3 tmr4 1 tmr5 tmr4 1 tmr5 tmr2 01 tmr5 tmr4 10 tmr3 tmr6 10 tmr5 tmr6 11 reserved ( 1 ) 11 tmr5 tmr8 note 1: do not use the reserved bits. ccptmrs2 register ccp8 ccp8 devices with 32 kbytes ccp9 ( 1 ) ccp10 ( 1 ) c8tsel <1:0> capture/ compare mode pwm mode c8tsel <1:0> capture/ compare mode pwm mode c9tsel0 capture/ compare mode pwm mode c10tsel0 capture/ compare mode pwm mode 00 tmr1 tmr2 00 tmr1 tmr2 0 tmr1 tmr2 0 tmr1 tmr2 01 tmr7 tmr4 01 tmr1 tmr4 1 tmr7 tmr4 1 tmr7 tmr2 10 tmr7 tmr6 10 tmr1 tmr6 11 reserved ( 2 ) 11 reserved ( 2 ) note 1: the module is not available for devices with 32 kbytes of program memory (pic18f65k22 and pic18f85k22). 2: do not use the reserved setting. downloaded from: http:///
pic18f87k22 family ds39960d-page 250 ? 2009-2011 microchip technology inc. 19.1.2 open-drain output option when operating in output mode (the compare or pwm modes), the drivers for the ccpx pins can be optionally configured as open-drain outputs. this feature allows the voltage level on the pin to be pulled to a higher level through an external pull-up resistor and allows the output to communicate with external circuits without the need for additional level shifters. the open-drain output option is controlled by the ccpxod bits (odcon2<7:0>). setting the appropri- ate bit configures the pin for the corresponding module for open-drain operation. 19.1.3 pin assignment for ccp6, ccp7, ccp8 and ccp9 the pin assignment for ccp6/7/8/9 (capture input, compare and pwm output) can change, based on the device configuration. the eccpmx configuration bit (config3h<1>) determines the pin to which ccp6/7/8/9 is multiplexed. the pin assignments for these ccp modules are given in table 19-4 . table 19-4: ccp pin assignment 19.2 capture mode in capture mode, the ccpr4h:ccpr4l register pair captures the 16-bit value of the timer register selected in the ccptmrs1 when an event occurs on the ccp4 pin. an event is defined as one of the following: every falling edge every rising edge every 4th rising edge every 16th rising edge the event is selected by the mode select bits, ccp4m<3:0> (ccp4con<3:0>). when a capture is made, the interrupt request flag bit, ccp4if (pir4<1>), is set. (it must be cleared in software.) if another capture occurs before the value in ccpr4 is read, the old captured value is overwritten by the new captured value. figure 19-1 shows the capture mode block diagram. 19.2.1 ccp pin configuration in capture mode, the appropriate ccpx pin should be configured as an input by setting the corresponding tris direction bit. 19.2.2 timer1/3/5/7 mode selection for the available timers (1/3/5/7) to be used for the capture feature, the used timers must be running in timer mode or synchronized counter mode. in asynchronous counter mode, the capture operation may not work. the timer to be used with each ccp module is selected in the ccptmrsx registers. (see section 19.1.1 ccp modules and timer resources .) details of the timer assignments for the ccp modules are given in tab le 1 9- 2 and table 19-3 . eccpmx value pin mapped to ccp6 ccp7 ccp8 cc9 1 (default) re6 re5 re4 re3 0 rh7 rh6 rh5 rh4 note: if rc1 or re7 is configured as a ccp4 output, a write to the port causes a capture condition. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 251 pic18f87k22 family figure 19-1: capture mode operation block diagram 19.2.3 software interrupt when the capture mode is changed, a false capture interrupt may be generated. the user should keep the ccp4ie bit (pie4<1>) clear to avoid false interrupts and should clear the flag bit, ccp4if, following any such change in operating mode. 19.2.4 ccp prescaler there are four prescaler settings in capture mode. they are specified as part of the operating mode selected by the mode select bits (ccp4m<3:0>). whenever the ccp module is turned off, or the ccp module is not in capture mode, the prescaler counter is cleared. this means that any reset will clear the prescaler counter. switching from one capture prescaler to another may generate an interrupt. doing that will also not clear the prescaler counter C meaning the first capture may be from a non-zero prescaler. example 19-1 shows the recommended method for switching between capture prescalers. this example also clears the prescaler counter and will not generate the false interrupt. example 19-1: changing between capture prescalers ccpr5h ccpr5l tmr1h tmr1l set ccp5if tmr5 enable q1:q4 ccp5con<3:0> ccp5 pin prescaler ? 1, 4, 16 and edge detect tmr1 enable c5tsel0 c5tsel0 ccpr4h ccpr4l tmr1h tmr1l set ccp4if tmr3 enable ccp4con<3:0> ccp4 pin prescaler ? 1, 4, 16 tmr3h tmr3l tmr1 enable c4tsel0 c4tsel1 c4tsel0 c4tsel1 tmr5h tmr5l and edge detect 4 4 4 note: this block diagram uses ccp4 and ccp5, and their appropr iate timers as an example. for details on all of the ccp modules and their timer assignments, see table 19-2 and table 19-3 . clrf ccp4con ; turn ccp module off movlw new_capt_ps ; load wreg with the ; new prescaler mode; value and ccp on movwf ccp4con ; load ccp4con with ; this value downloaded from: http:///
pic18f87k22 family ds39960d-page 252 ? 2009-2011 microchip technology inc. 19.3 compare mode in compare mode, the 16-bit ccpr4 register value is constantly compared against the timer register pair value selected in the ccptmr1 register. when a match occurs, the ccp4 pin can be: driven high driven low toggled (high-to-low or low-to-high) unchanged (that is, reflecting the state of the i/o latch) the action on the pin is based on the value of the mode select bits (ccp4m<3:0>). at the same time, the interrupt flag bit, ccp4if, is set. figure 19-2 gives the compare mode block diagram 19.3.1 ccp pin configuration the user must configure the ccpx pin as an output by clearing the appropriate tris bit. 19.3.2 timer1/3/5/7 mode selection if the ccp module is using the compare feature in conjunction with any of the timer1/3/5/7 timers, the timers must be running in timer mode or synchronized counter mode. in asynchronous counter mode, the compare operation may not work. 19.3.3 software interrupt mode when the generate software interrupt mode is chosen (ccp4m<3:0> = 1010 ), the ccp4 pin is not affected. only a ccp interrupt is generated, if enabled, and the ccp4ie bit is set. 19.3.4 special event trigger both ccp modules are equipped with a special event trigger. this is an internal hardware signal generated in compare mode to trigger actions by other modules. the special event trigger is enabled by selecting the compare special event trigger mode (ccp4m<3:0> = 1011 ). for either ccp module, the special event trigger resets the timer register pair for whichever timer resource is currently assigned as the modules time base. this allows the ccprx registers to serve as a programmable period register for either timer. the special event trigger for ccp4 cannot start an a/d conversion. note: clearing the ccp4con register will force the rc1 or re7 compare output latch (depending on device configuration) to the default low level. this is not the portc or porte i/o data latch. note: details of the timer assignments for the ccp modules are given in table 19-2 and ta b l e 1 9 - 3 . note: the special event trigger of eccp2 can start an a/d conversion, but the a/d converter must be enabled. for more information, see section 19.0 capture/compare/pwm (ccp) modules . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 253 pic18f87k22 family figure 19-2: compare mode operat ion block diagram table 19-5: registers associated with capture, compare, timer1/3/5/7 name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif rcon ipen sboren cm ri to pd por bor pir4 ccp10if ( 1 ) ccp9if ( 1 ) ccp8if ccp7if ccp6if ccp5if ccp4if ccp3if pie4 ccp10ie ( 1 ) ccp9ie ( 1 ) ccp8ie ccp7ie ccp6ie ccp5ie ccp4ie ccp3ie ipr4 ccp10ip ( 1 ) ccp9ip ( 1 ) ccp8ip ccp7ip ccp6ip ccp5ip ccp4ip ccp3ip trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 trise trise7 trise6 trise5 trise4 trise3 trise2 trise1 trise0 trish ( 2 ) trish7 trish6 trish5 trish4 trish3 trish2 trish1 trish0 tmr1l timer1 register low byte legend: = unimplemented, read as 0 . shaded cells are not used by capture/compare or timer1/3/5/7. note 1: unimplemented on devices with a program memory of 32 kbytes (pic18f65k22 and pic18f85k22). 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . ccpr5h ccpr5l tmr1h tmr1l comparator q s r output logic special event trigger set ccp5if ccp5 pin tris ccp5con<3:0> output enable tmr5h tmr5l 1 0 compare 4 (timer1/5 reset) match note: this block diagram uses ccp4 and ccp5, and their appr opriate timers as an example. for details on all of the ccp modules and their timer assignments, see table 19-2 and table 19-3 . tmr1h tmr1l tmr5h tmr5l ccpr4h ccpr4l comparator c4tsel1 set ccp4if 1 0 q s r output logic special event trigger ccp4 pin tris ccp4con<3:0> output enable 4 (timer1/timer3 reset, a/d trigger) compare match c5tsel0 c4tsel0 downloaded from: http:///
pic18f87k22 family ds39960d-page 254 ? 2009-2011 microchip technology inc. tmr1h timer1 register high byte tmr3l timer3 register low byte tmr3h timer3 register high byte tmr5l timer5 register low byte tmr5h timer5 register high byte tmr7l ( 1 ) timer7 register low byte tmr7h ( 1 ) timer7 register high byte t1con tmr1cs1 tmr1cs0 t1c kps1 t1ckps0 soscen t1sync rd16 tmr1on t3con tmr3cs1 tmr3cs0 t3c kps1 t3ckps0 soscen t3sync rd16 tmr3on t5con tmr5cs1 tmr5cs0 t5c kps1 t5ckps0 soscen t5sync rd16 tmr5on t7con ( 1 ) tmr7cs1 tmr7cs0 t7ckps1 t7ckps0 soscen t7sync rd16 tmr7on ccpr4l capture/compare/pwm register 4 low byte ccpr4h capture/compare/pwm register 4 high byte ccpr5l capture/compare/pwm register 5 low byte ccpr5h capture/compare/pwm register 5 high byte ccpr6l capture/compare/pwm register 6 low byte ccpr6h capture/compare/pwm register 6 high byte ccpr7l capture/compare/pwm register 7 low byte ccpr7h capture/compare/pwm register 7 high byte ccpr8l capture/compare/pwm register 8 low byte ccpr8h capture/compare/pwm register 8 high byte ccpr9l ( 1 ) capture/compare/pwm register 9 low byte ccpr9h ( 1 ) capture/compare/pwm register 9 high byte ccpr10l ( 1 ) capture/compare/pwm register 10 low byte ccpr10h ( 1 ) capture/compare/pwm register 10 high byte ccp4con dc4b1 dc4b0 ccp4m3 ccp4m2 ccp4m1 ccp4m0 ccp5con dc5b1 dc5b0 ccp5m3 ccp5m2 ccp5m1 ccp5m0 ccp6con dc6b1 dc6b0 ccp6m3 ccp6m2 ccp6m1 ccp6m0 ccp7con dc7b1 dc7b0 ccp7m3 ccp7m2 ccp7m1 ccp7m0 ccp8con dc8b1 dc8b0 ccp8m3 ccp8m2 ccp8m1 ccp8m0 ccp9con ( 1 ) dc9b1 dc9b0 ccp9m3 ccp9m2 ccp9m1 ccp9m0 ccp10con ( 1 ) dc10b1 dc10b0 ccp10m3 ccp10m2 ccp10m1 ccp10m0 ccptmrs1 c7tsel1 c7tsel0 c6tsel0 c5tsel0 c4tsel1 c4tsel0 ccptmrs2 c10tsel0 ( 1 ) c9tsel0 ( 1 ) c8tsel1 c8tsel0 pmd3 ccp10md ( 1 ) ccp9md ( 1 ) ccp8md ccp7md ccp6md ccp5md ccp4md tmr12md ( 1 ) table 19-5: registers associated with capture, compare, timer1/3/5/7 (continued) name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 legend: = unimplemented, read as 0 . shaded cells are not used by capture/compare or timer1/3/5/7. note 1: unimplemented on devices with a program memory of 32 kbytes (pic18f65k22 and pic18f85k22). 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 255 pic18f87k22 family 19.4 pwm mode in pulse-width modulation (pwm) mode, the ccp4 pin produces up to a 10-bit resolution pwm output. since the ccp4 pin is multiplexed with a portc or porte data latch, the appropriate tris bit must be cleared to make the ccp4 pin an output. figure 19-3 shows a simplified block diagram of the eccp1 module in pwm mode. for a step-by-step procedure on how to set up the ccp module for pwm operation, see section 19.4.3 setup for pwm operation . figure 19-3: simplified pwm block diagram a pwm output ( figure 19-4 ) has a time base (period) and a time that the output stays high (duty cycle). the frequency of the pwm is the inverse of the period (1/period). figure 19-4: pwm output 19.4.1 pwm period the pwm period is specified by writing to the pr2 register. the pwm period can be calculated using the following formula: equation 19-1: pwm frequency is defined as 1/[pwm period]. when tmr2 is equal to pr2, the following three events occur on the next increment cycle: tmr2 is cleared the ccp4 pin is set (an exception: if pwm duty cycle = 0%, the ccp4 pin will not be set) the pwm duty cycle is latched from ccpr4l into ccpr4h note: clearing the ccp4con register will force the rc1 or re7 output latch (depending on device configuration) to the default low level. this is not the portc or porte i/o data latch. ccpr4l ccpr4h (slave) comparator tmr2 comparator pr2 (note 1) r q s duty cycle registers ccp4con<5:4> clear timer, eccp1 pin and latch d.c. trisc<2> rc2/eccp1 note 1: the 8-bit tmr2 value is concatenated with the 2-bit internal q clock, or 2 bits of the prescaler, to create the 10-bit time base. 2: ccp4 and its appropriate timers are used as an example. for details on all of the ccp modules and their timer assignments, see ta b l e 1 9 - 2 and table 19-3 . (note 2) (note 2) note: the timer2 postscalers (see section 15.0 timer2 module ) are not used in the determination of the pwm frequency. the postscaler could be used to have a servo update rate at a different frequency than the pwm output. period duty cycle tmr2 = pr2 tmr2 = duty cycle tmr2 = pr2 pwm period = [(pr2) + 1] 4 t osc (tmr2 prescale value) downloaded from: http:///
pic18f87k22 family ds39960d-page 256 ? 2009-2011 microchip technology inc. 19.4.2 pwm duty cycle the pwm duty cycle is specified to use ccp4, as an example, by writing to the ccpr4l register and to the ccp4con<5:4> bits. up to 10-bit resolution is avail- able. the ccpr4l contains the eight msbs and the ccp4con<5:4> bits contain the two lsbs. this 10-bit value is represented by ccpr4l:ccp4con<5:4>. the following equation is used to calculate the pwm duty cycle in time: equation 19-2: ccpr4l and ccp4con<5:4> can be written to at any time, but the duty cycle value is not latched into ccpr4h until after a match between pr2 and tmr2 occurs (that is, the period is complete). in pwm mode, ccpr4h is a read-only register. the ccpr4h register and a two-bit internal latch are used to double-buffer the pwm duty cycle. this double-buffering is essential for glitchless pwm operation. when the ccpr4h and two-bit latch match tmr2, concatenated with an internal two-bit q clock or two bits of the tmr2 prescaler, the ccp4 pin is cleared. the maximum pwm resolution (bits) for a given pwm frequency is shown in equation 19-3 : equation 19-3: table 19-6: example pwm frequencies and resolutions at 40 mhz 19.4.3 setup for pwm operation to configure the ccp module for pwm operation, using ccp4 as an example: 1. set the pwm period by writing to the pr2 register. 2. set the pwm duty cycle by writing to the ccpr4l register and ccp4con<5:4> bits. 3. make the ccp4 pin an output by clearing the appropriate tris bit. 4. set the tmr2 prescale value, then enable timer2 by writing to t2con. 5. configure the ccp4 module for pwm operation. pwm duty cycle = (ccpr4l:ccp4con<5:4>) t osc (tmr2 prescale value) note: if the pwm duty cycle value is longer than the pwm period, the ccp4 pin will not be cleared. f osc f pwm --------------- ?? ?? log 2 ?? log ----------------------------- b i t s = pwm resolution (max) pwm frequency 2.44 khz 9.77 khz 39.06 khz 156.25 khz 312.50 khz 416.67 khz t i m e r p r e s c a l e r ( 1 , 4 , 1 6 )1 641111 pr2 value ffh ffh ffh 3fh 1fh 17h maximum resolution (bits) 10 10 10 8 7 6.58 table 19-7: registers associated with pwm and timers name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif rcon ipen sboren cm ri to pd por bor pir4 ccp10if ( 1 ) ccp9if ( 1 ) ccp8if ccp7if ccp6if ccp5if ccp4if ccp3if pie4 ccp10ie ( 1 ) ccp9ie ( 1 ) ccp8ie ccp7ie ccp6ie ccp5ie ccp4ie ccp3ie ipr4 ccp10ip ( 1 ) ccp9ip ( 1 ) ccp8ip ccp7ip ccp6ip ccp5ip ccp4ip ccp3ip trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 trise trise7 trise6 trise5 trise4 trise3 trise2 trise1 trise0 legend: = unimplemented, read as 0 . shaded cells are not used by pwm or timer2/4/6/8. note 1: unimplemented on devices with a program memory of 32 kbytes (pic18f65k22 and pic18f85k22). 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 257 pic18f87k22 family trish ( 2 ) trish7 trish6 trish5 trish4 trish3 trish2 trish1 trish0 tmr2 timer2 register tmr4 timer4 register tmr6 timer6 register tmr8 timer8 register pr2 timer2 period register pr4 timer4 period register pr6 timer6 period register pr8 timer8 period register t2con t2outps3 t2outps2 t2outps1 t2outps0 tmr2on t2ckps1 t2ckps0 t4con t4outps3 t4outps2 t4outps1 t4outps0 tmr4on t4ckps1 t4ckps0 t6con t6outps3 t6outps2 t6outps1 t6outps0 tmr6on t6ckps1 t6ckps0 t8con t8outps3 t8outps2 t8outps1 t8outps0 tmr8on t8ckps1 t8ckps0 ccpr4l capture/compare/pwm register 4 low byte ccpr4h capture/compare/pwm register 4 high byte ccpr5l capture/compare/pwm register 5 low byte ccpr5h capture/compare/pwm register 5 high byte ccpr6l capture/compare/pwm register 6 low byte ccpr6h capture/compare/pwm register 6 high byte ccpr7l capture/compare/pwm register 7 low byte ccpr7h capture/compare/pwm register 7 high byte ccpr8l capture/compare/pwm register 8 low byte ccpr8h capture/compare/pwm register 8 high byte ccpr9l ( 1 ) capture/compare/pwm register 9 low byte ccpr9h ( 1 ) capture/compare/pwm register 9 high byte ccpr10l ( 1 ) capture/compare/pwm register 10 low byte ccpr10h ( 1 ) capture/compare/pwm register 10 high byte ccp4con dc4b1 dc4b0 ccp4m3 ccp4m2 ccp4m1 ccp4m0 ccp5con dc5b1 dc5b0 ccp5m3 ccp5m2 ccp5m1 ccp5m0 ccp6con dc6b1 dc6b0 ccp6m3 ccp6m2 ccp6m1 ccp6m0 ccp7con dc7b1 dc7b0 ccp7m3 ccp7m2 ccp7m1 ccp7m0 ccp8con dc8b1 dc8b0 ccp8m3 ccp8m2 ccp8m1 ccp8m0 ccp9con ( 1 ) dc9b1 dc9b0 ccp9m3 ccp9m2 ccp9m1 ccp9m0 ccp10con ( 1 ) dc10b1 dc10b0 ccp10m3 ccp10m2 ccp10m1 ccp10m0 ccptmrs1 c7tsel1 c7tsel0 c6tsel0 c5tsel0 c4tsel1 c4tsel0 ccptmrs2 c10tsel0 ( 1 ) c9tsel0 ( 1 ) c8tsel1 c8tsel0 pmd3 ccp10md ( 1 ) ccp9md ( 1 ) ccp8md ccp7md ccp6md ccp5md ccp4md tmr12md ( 1 ) table 19-7: registers associated with pwm and timers (continued) name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 legend: = unimplemented, read as 0 . shaded cells are not used by pwm or timer2/4/6/8. note 1: unimplemented on devices with a program memory of 32 kbytes (pic18f65k22 and pic18f85k22). 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . downloaded from: http:///
pic18f87k22 family ds39960d-page 258 ? 2009-2011 microchip technology inc. notes: downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 259 pic18f87k22 family 20.0 enhanced capture/compare/pwm (eccp) module pic18f87k22 family devices have three enhanced capture/compare/pwm (eccp) modules: eccp1, eccp2 and eccp3. these modules contain a 16-bit register, which can operate as a 16-bit capture register, a 16-bit compare register or a pwm master/slave duty cycle register. these eccp modules are upward compatible with ccp. eccp1, eccp2 and eccp3 are implemented as stan- dard ccp modules with enhanced pwm capabilities. these include: provision for two or four output channels output steering modes programmable polarity programmable dead-band control automatic shutdown and restart the enhanced features are discussed in detail in section 20.4 pwm (enhanced mode) . the eccp1, eccp2 and eccp3 modules use the control registers: ccp1con, ccp2con and ccp3con. the control registers, ccp4con through ccp10con, are for the modules, ccp4 through ccp10. note: throughout this section, generic references are used for register and bit names that are the same, except for an x variable that indi- cates the items association with the eccp1, eccp2 or eccp3 module. for example, the control register is named ccpxcon and refers to ccp1con, ccp2con and ccp3con. downloaded from: http:///
pic18f87k22 family ds39960d-page 260 ? 2009-2011 microchip technology inc. register 20-1: ccpxcon: enhanced capture/compare/pwmx control r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 pxm1 pxm0 dcxb1 dcxb0 ccpxm3 ccpxm2 ccpxm1 ccpxm0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-6 pxm<1:0>: enhanced pwm output configuration bits if ccpxm<3:2> = 00 , 01 , 10 : xx = pxa is assigned as capture/compare input/output; pxb, pxc and pxd are assigned as port pins if ccpxm<3:2> = 11 : 00 = single output: pxa, pxb, pxc and pxd are controlled by steering (see section 20.4.7 pulse steering mode ) 01 = full-bridge output forward: pxd is modulated; pxa is active; pxb, pxc are inactive 10 = half-bridge output: pxa, pxb are modulated with dead-band control; pxc and pxd are assigned as port pins 11 = full-bridge output reverse: pxb is modulated; pxc is active; pxa and pxd are inactive bit 5-4 dcxb<1:0> : pwm duty cycle bit 1 and bit 0 capture mode: unused. compare mode: unused. pwm mode: these bits are the two lsbs of the 10-bit pwm duty cycle. the eight msbs of the duty cycle are found in ccprxl. bit 3-0 ccpxm<3:0> : eccpx mode select bits 0000 = capture/compare/pwm off (resets eccpx module) 0001 = reserved 0010 = compare mode: toggle output on match 0011 = capture mode 0100 = capture mode: every falling edge 0101 = capture mode: every rising edge 0110 = capture mode: every fourth rising edge 0111 = capture mode: every 16 th rising edge 1000 = compare mode: initialize eccpx pin low, set output on compare match (set ccpxif) 1001 = compare mode: initialize eccpx pin high, clear output on compare match (set ccpxif) 1010 = compare mode: generate software interrupt only, eccpx pin reverts to i/o state 1011 = compare mode: trigger special event (eccpx resets tmr1 or tmr3, starts a/d conversion, sets ccpxif bit) 1100 = pwm mode: pxa and pxc are active-high; pxb and pxd are active-high 1101 = pwm mode: pxa and pxc are active-high; pxb and pxd are active-low 1110 = pwm mode: pxa and pxc are active-low; pxb and pxd are active-high 1111 = pwm mode: pxa and pxc are active-low; pxb and pxd are active-low downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 261 pic18f87k22 family register 20-2: ccptmrs0: ccp timer select 0 register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 c3tsel1 c3tsel0 c2tsel2 c2tsel1 c2tsel0 c1tsel2 c1tsel1 c1tsel0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-6 c3tsel<1:0>: eccp3 timer selection bits 00 = eccp3 is based off of tmr1/tmr2 01 = eccp3 is based off of tmr3/tmr4 10 = eccp3 is based off of tmr3/tmr6 11 = eccp3 is based off of tmr3/tmr8 bit 5-3 c2tsel<2:0>: eccp2 timer selection bits 000 = eccp2 is based off of tmr1/tmr2 001 = eccp2 is based off of tmr3/tmr4 010 = eccp2 is based off of tmr3/tmr6 011 = eccp2 is based off of tmr3/tmr8 100 = eccp2 is based off of tmr3/tmr10: option reserved on the 32-kbyte device variant; do not use 101 = reserved; do not use 110 = reserved; do not use 111 = reserved; do not use bit 2-0 c1tsel<2:0>: eccp1 timer selection bits 000 = eccp1 is based off of tmr1/tmr2 001 = eccp1 is based off of tmr3/tmr4 010 = eccp1 is based off of tmr3/tmr6 011 = eccp1 is based off of tmr3/tmr8 100 = eccp1 is based off of tmr3/tmr10: option reserved on the 32-kbyte device variant; do not use 101 = eccp1 is based off of tmr3/tmr12: option reserved on the 32-kbyte device variant; do not use 110 = reserved; do not use 111 = reserved; do not use downloaded from: http:///
pic18f87k22 family ds39960d-page 262 ? 2009-2011 microchip technology inc. in addition to the expanded range of modes available through the ccpxcon and eccpxas registers, the eccp modules have two additional registers associated with enhanced pwm operation and auto-shutdown features. they are: eccpxdel C enhanced pwm control pstrxcon C pulse steering control 20.1 eccp outputs and configuration the enhanced ccp module may have up to four pwm outputs, depending on the selected operating mode. the ccpxcon register is modified to allow control over four pwm outputs: eccpx/pxa, pxb, pxc and pxd. applications can use one, two or four of these outputs. the outputs that are active depend on the eccp selected operating mode. the pin assignments are summarized in table 20-3 . to configure the i/o pins as pwm outputs, the proper pwm mode must be selected by setting the pxm<1:0> and ccpxm<3:0> bits. the appropriate tris direction bits for the port pins must also be set as outputs. 20.1.1 eccp module and timer resources the eccp modules use timers, 1, 2, 3, 4, 6, 8, 10 or 12, depending on the mode selected. these timers are available to ccp modules in capture, compare or pwm modes, as shown in table 20-1 . table 20-1: eccp mode C timer resource the assignment of a particular timer to a module is determined by the timer to eccp enable bits in the ccptmrsx register ( register 20-2 ). the interactions between the two modules are depicted in figure 20-1 . capture operations are designed to be used when the timer is configured for synchronous counter mode. capture operations may not work as expected if the associated timer is configured for asynchronous counter mode. 20.1.2 eccp pin assignment the pin assignment for eccpx (capture input, compare and pwm output) can change, based on device configuration. the eccpmx (config3h<1>) configuration bit determines which pins eccp1 and eccp3 are multiplexed to. default/eccpmx = 1 : - eccp1 (p1b/p1c) is multiplexed onto re6 and re5 - eccp3 (p3b/p3c) is multiplexed onto re4 and re3 eccpmx = 0 : - eccp1 (p1b/p1c) is multiplexed onto rh7 and rh6 - eccp3 (p3b/p3c) is multiplexed onto rh5 and rh4. the pin assignment for eccp2 (capture input, compare and pwm output) can change, based on the device configuration. the ccp2mx configuration bit (config3h<0>) determines which pin eccp2 is multiplexed to. if ccp2mx = 1 (default) C eccp2 is multiplexed to rc1 if ccp2mx = 0 C eccp2 is multiplexed to re7 eccp mode timer resource capture timer1 or timer3 compare timer1 or timer3 pwm timer2, timer4, timer6, timer8, timer10 or timer12 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 263 pic18f87k22 family 20.2 capture mode in capture mode, the ccprxh:ccprxl register pair captures the 16-bit value of the tmr1 or tmr3 registers when an event occurs on the corresponding eccpx pin. an event is defined as one of the following: every falling edge every rising edge every fourth rising edge every 16 th rising edge the event is selected by the mode select bits, ccpxm<3:0> (ccpxcon<3:0>). when a capture is made, the interrupt request flag bit, ccpxif, is set (see table 20-2 ). the flag must be cleared by software. if another capture occurs before the value in the ccprxh/l register is read, the old captured value is overwritten by the new captured value. 20.2.1 eccp pin configuration in capture mode, the appropriate eccpx pin should be configured as an input by setting the corresponding tris direction bit. 20.2.2 timer1/2/3/4/6/8/10/12 mode selection the timers that are to be used with the capture feature (timer1 2, 3, 4, 6, 8, 10 or 12) must be running in timer mode or synchronized counter mode. in asynchro- nous counter mode, the capture operation may not work. the timer to be used with each eccp module is selected in the ccptmrs0 register ( register 20-2 ). 20.2.3 software interrupt when the capture mode is changed, a false capture interrupt may be generated. the user should keep the ccpxie interrupt enable bit clear to avoid false interrupts. the interrupt flag bit, ccpxif, should also be cleared following any such change in operating mode. 20.2.4 eccp prescaler there are four prescaler settings in capture mode; they are specified as part of the operating mode selected by the mode select bits (ccpxm<3:0>). whenever the eccp module is turned off, or capture mode is dis- abled, the prescaler counter is cleared. this means that any reset will clear the prescaler counter. switching from one capture prescaler to another may generate an interrupt. also, the prescaler counter will not be cleared; therefore, the first capture may be from a non-zero prescaler. example 20-1 provides the recommended method for switching between capture prescalers. this example also clears the prescaler counter and will not generate the false interrupt. example 20-1: changing between capture prescalers figure 20-1: capture mode operation block diagram table 20-2: eccp1/2/3 interrupt flag bits eccp module flag bit 1 pir3<1> 2 pir3<2> 3 pir4<0> note: if the eccpx pin is configured as an out- put, a write to the port can cause a capture condition. clrf ccp1con ; turn eccp module off movlw new_capt_ps ; load wreg with the ; new prescaler mode; value and eccp on movwf ccp1con ; load ccp1con with ; this value ccpr1h ccpr1l tmr1h tmr1l set ccp1if tmr3 enable q1:q4 ccp1con<3:0> eccp1 pin prescaler ? 1, 4, 16 and edge detect tmr1 enable c1tsel0 tmr3h tmr3l 4 4 c1tsel1 c1tsel2 c1tsel0 c1tsel1 c1tsel2 downloaded from: http:///
pic18f87k22 family ds39960d-page 264 ? 2009-2011 microchip technology inc. 20.3 compare mode in compare mode, the 16-bit ccprx register value is constantly compared against the timer register pair value selected in the ccptmr1 register. when a match occurs, the eccpx pin can be: driven high driven low toggled (high-to-low or low-to-high) unchanged (that is, reflecting the state of the i/o latch) the action on the pin is based on the value of the mode select bits (ccpxm<3:0>). at the same time, the interrupt flag bit, ccpxif, is set. 20.3.1 eccp pin configuration users must configure the eccpx pin as an output by clearing the appropriate tris bit. 20.3.2 timer1/2/3/4/6/8/10/12 mode selection timer1 2, 3, 4, 6, 8, 10 or 12 must be running in timer mode or synchronized counter mode if the eccp module is using the compare feature. in asynchronous counter mode, the compare operation will not work reliably. 20.3.3 software interrupt mode when the generate software interrupt mode is chosen (ccpxm<3:0> = 1010 ), the eccpx pin is not affected; only the ccpxif interrupt flag is affected. 20.3.4 special event trigger the eccp module is equipped with a special event trigger. this is an internal hardware signal generated in compare mode to trigger actions by other modules. the special event trigger is enabled by selecting the compare special event trigger mode (ccpxm<3:0> = 1011 ). the special event trigger resets the timer register pair for whichever timer resource is currently assigned as the modules time base. this allows the ccprx registers to serve as a programmable period register for either timer. the special event trigger can also start an a/d conver- sion. in order to do this, the a/d converter must already be enabled. figure 20-2: compare mode operation block diagram note: clearing the ccpxcon register will force the eccpx compare output latch (depending on device configuration) to the default low level. this is not the portx i/o data latch. tmr1h tmr1l tmr3h tmr3l ccpr1h ccpr1l comparator set ccp1if 1 0 q s r output logic eccp1 pin tris ccp1con<3:0> output enable 4 (timer1/timer3 reset, a/d trigger) compare match c1tsel0 c1tsel1 c1tsel2 special event trigger downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 265 pic18f87k22 family 20.4 pwm (enhanced mode) the enhanced pwm mode can generate a pwm signal on up to four different output pins with up to 10 bits of resolution. it can do this through four different pwm output modes: single pwm half-bridge pwm full-bridge pwm, forward mode full-bridge pwm, reverse mode to select an enhanced pwm mode, the pxm bits of the ccpxcon register must be set appropriately. the pwm outputs are multiplexed with i/o pins and are designated: pxa, pxb, pxc and pxd. the polarity of the pwm pins is configurable and is selected by setting the ccpxm bits in the ccpxcon register appropriately. table 20-1 provides the pin assignments for each enhanced pwm mode. figure 20-3 provides an example of a simplified block diagram of the enhanced pwm module. figure 20-3: example simplified block diagram of the enhanced pwm mode note: to prevent the generation of an incomplete waveform when the pwm is first enabled, the eccp module waits until the start of a new pwm period before generating a pwm signal. note 1: the tris register value for each pwm output must be configured appropriately. 2: any pin not used by an enhanced pwm mode is available for alternate pin functions. ccpr1l ccpr1h (slave) comparator tmr2 comparator pr2 (note 1) rq s duty cycle registers dc1b<1:0> clear timer2, toggle pwm pin and latch duty cycle note 1: the 8-bit tmr2 register is concatenated with the 2-bit internal q clock, or 2 bits of the prescaler to create the 10-bit time base. tris eccp1/output pi n tris output pi n tris output pi n tris output pi n output controller pxm<1:0> 2 ccpxm<3:0> 4 eccp1del eccpx/pxa pxb pxc pxd downloaded from: http:///
pic18f87k22 family ds39960d-page 266 ? 2009-2011 microchip technology inc. table 20-3: example pin assignments for various pwm enhanced modes figure 20-4: example pwm (enhanced mode) output relationships (active-high state) eccp mode pxm<1:0> pxa pxb pxc pxd single 00 yes ( 1 ) yes ( 1 ) yes ( 1 ) yes ( 1 ) half-bridge 10 yes yes no no full-bridge, forward 01 yes yes yes yes full-bridge, reverse 11 yes yes yes yes note 1: outputs are enabled by pulse steering in single mode (see register 20-5 ). 0 period 0010 01 11 signal pr2 + 1 pxm<1:0> pxa modulated pxa modulated pxb modulated pxa active pxb inactive pxc inactive pxd modulated pxa inactive pxb modulated pxc active pxd inactive pulse width (single output) (half-bridge) (full-bridge, forward) (full-bridge, reverse) delay (1) delay (1) relationships: period = 4 * t osc * (pr2 + 1) * (tmr2 prescale value) pulse width = t osc * (ccprxl<7:0>:ccpxcon<5:4>) * (tmr2 prescale value) delay = 4 * t osc * (eccpxdel<6:0>) note 1: dead-band delay is programmed using the eccpxdel register (see section 20.4.6 programmable dead-band delay mode ). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 267 pic18f87k22 family figure 20-5: example enhanced pwm outp ut relationships (active-low state) 0 period 0010 01 11 signal pr2 + 1 pxm<1:0> pxa modulated pxa modulated pxb modulated pxa active pxb inactive pxc inactive pxd modulated pxa inactive pxb modulated pxc active pxd inactive pulse width (single output) (half-bridge) (full-bridge, forward) (full-bridge, reverse) delay (1) delay (1) relationships: period = 4 * t osc * (pr2 + 1) * (tmr2 prescale value) pulse width = t osc * (ccprxl<7:0>:ccpxcon<5:4>) * (tmr2 prescale value) delay = 4 * t osc * (eccpxdel<6:0>) note 1: dead-band delay is programmed using the eccp1del register (see section 20.4.6 programmable dead-band delay mode ). downloaded from: http:///
pic18f87k22 family ds39960d-page 268 ? 2009-2011 microchip technology inc. 20.4.1 half-bridge mode in half-bridge mode, two pins are used as outputs to drive push-pull loads. the pwm output signal is output on the pxa pin, while the complementary pwm output signal is output on the pxb pin (see figure 20-6 ). this mode can be used for half-bridge applications, as shown in figure 20-7 , or for full-bridge applications, where four power switches are being modulated with two pwm signals. in half-bridge mode, the programmable dead-band delay can be used to prevent shoot-through current in half-bridge power devices. the value of the pxdc<6:0> bits of the eccpxdel register sets the number of instruction cycles before the output is driven active. if the value is greater than the duty cycle, the corresponding output remains inactive during the entire cycle. for more details on the dead-band delay operations, see section 20.4.6 programmable dead-band delay mode . since the pxa and pxb outputs are multiplexed with the port data latches, the associated tris bits must be cleared to configure pxa and pxb as outputs. figure 20-6: example of half-bridge pwm output figure 20-7: example of half-bridge applications period pulse width td td (1) pxa (2) pxb (2) td = dead-band delay period (1) (1) note 1: at this time, the tmr2 register is equal to the pr2 register. 2: output signals are shown as active-high. pxapxb fet driver fet driver load + - + - fet driver fet driver v+ load fet driver fet driver pxapxb standard half-bridge circuit (push-pull) half-bridge output driving a full-bridge circuit downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 269 pic18f87k22 family 20.4.2 full-bridge mode in full-bridge mode, all four pins are used as outputs. an example of a full-bridge application is provided in figure 20-8 . in the forward mode, the pxa pin is driven to its active state and the pxd pin is modulated, while the pxb and pxc pins are driven to their inactive state, as provided in figure 20-9 . in the reverse mode, the pxc pin is driven to its active state and the pxb pin is modulated, while the pxa and pxd pins are driven to their inactive state, as provided figure 20-9 . the pxa, pxb, pxc and pxd outputs are multiplexed with the port data latches. the associated tris bits must be cleared to configure the pxa, pxb, pxc and pxd pins as outputs. figure 20-8: example of full-bridge application pxapxc fet driver fet driver v+ v- load fet driver fet driver pxbpxd qaqb qd qc downloaded from: http:///
pic18f87k22 family ds39960d-page 270 ? 2009-2011 microchip technology inc. figure 20-9: example of full-bridge pwm output period pulse width pxa (2) pxb (2) pxc (2) pxd (2) forward mode (1) period pulse width pxa (2) pxc (2) pxd (2) pxb (2) reverse mode (1) (1) (1) note 1: at this time, the tmr2 register is equal to the pr2 register. 2: the output signal is shown as active-high. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 271 pic18f87k22 family 20.4.2.1 direction change in full-bridge mode in full-bridge mode, the pxm1 bit in the ccpxcon register allows users to control the forward/reverse direction. when the application firmware changes this direction control bit, the module will change to the new direction on the next pwm cycle. a direction change is initiated in software by changing the pxm1 bit of the ccpxcon register. the following sequence occurs prior to the end of the current pwm period: the modulated outputs (pxb and pxd) are placed in their inactive state. the associated unmodulated outputs (pxa and pxc) are switched to drive in the opposite direction. pwm modulation resumes at the beginning of the next period. for an illustration of this sequence, see figure 20-10 . the full-bridge mode does not provide a dead-band delay. as one output is modulated at a time, a dead-band delay is generally not required. there is a situation where a dead-band delay is required. this situation occurs when both of the following conditions are true: the direction of the pwm output changes when the duty cycle of the output is at or near 100%. the turn-off time of the power switch, including the power device and driver circuit, is greater than the turn-on time. figure 20-11 shows an example of the pwm direction changing from forward to reverse, at a near 100% duty cycle. in this example, at time, t1, the pxa and pxd outputs become inactive, while the pxc output becomes active. since the turn-off time of the power devices is longer than the turn-on time, a shoot-through current will flow through power devices, qc and qd (see figure 20-8 ), for the duration of t. the same phenomenon will occur to power devices, qa and qb, for pwm direction change from reverse to forward. if changing pwm direction at high duty cycle is required for an application, two possible solutions for eliminating the shoot-through current are: reduce pwm duty cycle for one pwm period before changing directions. use switch drivers that can drive the switches off faster than they can drive them on. other options to prevent shoot-through current may exist. figure 20-10: example of pwm direction change pulse width period (1) signal note 1: the direction bit, pxm1 of the ccpxcon register, is written any time during the pwm cycle. 2: when changing directions, the pxa and pxc signals switch before the end of the current pwm cycle. the modulated pxb and pxd signals are inactive at this time. the length of this time is: (1/f osc ) tmr2 prescale value . period (2) pxa (active-high) pxb (active-high) pxc (active-high) pxd (active-high) pulse width downloaded from: http:///
pic18f87k22 family ds39960d-page 272 ? 2009-2011 microchip technology inc. figure 20-11: example of pwm direct ion change at near 100% duty cycle (1) 20.4.3 start-up considerations when any pwm mode is used, the application hardware must use the proper external pull-up and/or pull-down resistors on the pwm output pins. the ccpxm<1:0> bits of the ccpxcon register allow the user to choose whether the pwm output signals are active-high or active-low for each pair of pwm output pins (pxa/pxc and pxb/pxd). the pwm output polarities must be selected before the pwm pin output drivers are enabled. changing the polarity configura- tion while the pwm pin output drivers are enabled is not recommended since it may result in damage to the application circuits. the pxa, pxb, pxc and pxd output latches may not be in the proper states when the pwm module is initialized. enabling the pwm pin output drivers at the same time as the enhanced pwm modes may cause damage to the application circuit. the enhanced pwm modes must be enabled in the proper output mode and complete a full pwm cycle before enabling the pwm pin output drivers. the completion of a full pwm cycle is indicated by the tmr2if or tmr4if bit of the pir1 or pir5 register being set as the second pwm period begins. 20.4.4 enhanced pwm auto-shutdown mode the pwm mode supports an auto-shutdown mode that will disable the pwm outputs when an external shutdown event occurs. auto-shutdown mode places the pwm output pins into a predetermined state. this mode is used to help prevent the pwm from damaging the application. the auto-shutdown sources are selected using the eccpxas<2:0> bits (eccpxas<6:4>). a shutdown event may be generated by: a logic 0 on the pin that is assigned the flt0 input function c1 comparator c2 comparator setting the eccpxase bit in firmware a shutdown condition is indicated by the eccpxase (auto-shutdown event status) bit (eccpxas<7>). if the bit is a 0 , the pwm pins are operating normally. if the bit is a 1 , the pwm outputs are in the shutdown state. forward period reverse period pxa t on (2) t off (3) t = t off C t on (2,3) pxb pxc pxd external switch d potential shoot-through current note 1: all signals are shown as active-high. 2: t on is the turn-on delay of pow er switch, qc, and its driver. 3: t off is the turn-off delay of power switch, qd, and its driver. external switch c t1 pw pw note: when the microcontroller is released from reset, all of the i/o pins are in the high-impedance state. the external circuits must keep the power switch devices in the off state until the micro- controller drives the i/o pins with the proper signal levels or activates the pwm output(s). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 273 pic18f87k22 family when a shutdown event occurs, two things happen: the eccpxase bit is set to 1 . the eccpxase will remain set until cleared in firmware or an auto-restart occurs. (see section 20.4.5 auto-restart mode .) the enabled pwm pins are asynchronously placed in their shutdown states. the pwm output pins are grouped into pairs (pxa/pxc) and (pxb/pxd). the state of each pin pair is determined by the pssxac and pssxbd bits (eccpxas<3:2> and <1:0>, respectively). each pin pair may be placed into one of three states: drive logic 1 drive logic 0 tri-state (high-impedance) register 20-3: eccpxas: eccpx auto-shutdown control register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 eccpxase eccpxas2 eccpxas1 eccpxas0 pssxac1 pssxac0 pssxbd1 pssxbd0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 eccpxase: eccp auto-shutdown event status bit 1 = a shutdown event has occurred; eccp outputs are in a shutdown state 0 = eccp outputs are operating bit 6-4 eccpxas<2:0>: eccp auto-shutdown source select bits 000 = auto-shutdown is disabled 001 = comparator c1out output is high 010 = comparator c2out output is high 011 = either comparator c1out or c2out is high 100 =v il on flt0 pin 101 =v il on flt0 pin or comparator c1out output is high 110 =v il on flt0 pin or comparator c2out output is high 111 =v il on flt0 pin or comparator c1out or comparator c2out is high bit 3-2 pssxac<1:0>: pxa and pxc pins shutdown state control bits 00 = drive pins, pxa and pxc, to 0 01 = drive pins, pxa and pxc, to 1 1x = pxa and pxc pins tri-state bit 1-0 pssxbd<1:0>: pins pxb and pxd shutdown state control bits 00 = drive pins, pxb and pxd, to 0 01 = drive pins, pxb and pxd, to 1 1x = pxb and pxd pins tri-state note 1: the auto-shutdown condition is a level-based signal, not an edge-based signal. as long as the level is present, the auto-shutdown will persist. 2: writing to the eccpxase bit is disabled while an auto-shutdown condition persists. 3: once the auto-shutdown condition has been removed and the pwm restarted (either through firmware or auto-restart), the pwm signal will always restart at the beginning of the next pwm period. downloaded from: http:///
pic18f87k22 family ds39960d-page 274 ? 2009-2011 microchip technology inc. figure 20-12: pwm auto-shutdown wi th firmware restart (pxrsen = 0 ) 20.4.5 auto-restart mode the enhanced pwm can be configured to automatically restart the pwm signal once the auto-shutdown condi- tion has been removed. auto-restart is enabled by setting the pxrsen bit (eccpxdel<7>). if auto-restart is enabled, the eccpxase bit will remain set as long as the auto-shutdown condition is active. when the auto-shutdown condition is removed, the eccpxase bit will be cleared via hardware and normal operation will resume. the module will wait until the next pwm period begins, however, before re-enabling the output pin. this behav- ior allows the auto-shutdown with auto-restart features to be used in applications based on current mode of pwm control. figure 20-13: pwm auto-shutdown wi th auto-restart enabled (pxrsen = 1 ) shutdown pwm eccpxase bit activity event shutdown event occurs shutdown event clears pwm resumes normal pwm start of pwm period eccpxase cleared by firmware pwm period shutdown pwm eccpxase bit activity event shutdown event occurs shutdown event clears pwm resumes normal pwm start of pwm period pwm period downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 275 pic18f87k22 family 20.4.6 programmable dead-band delay mode in half-bridge applications, where all power switches are modulated at the pwm frequency, the power switches normally require more time to turn off than to turn on. if both the upper and lower power switches are switched at the same time (one turned on and the other turned off), both switches may be on for a short period until one switch completely turns off. during this brief interval, a very high current (shoot-through current) will flow through both power switches, shorting the bridge supply. to avoid this potentially destructive shoot-through current from flowing during switching, turning on either of the power switches is normally delayed to allow the other switch to completely turn off. in half-bridge mode, a digitally programmable dead-band delay is available to avoid shoot-through current from destroying the bridge power switches. the delay occurs at the signal transition from the non-active state to the active state. for an illustration, see figure 20-14 . the lower seven bits of the associated eccpxdel register ( register 20-4 ) set the delay period in terms of microcontroller instruction cycles (t cy or 4 t osc ). figure 20-14: example of half-bridge pwm output figure 20-15: example of half-bridge applications period pulse width td td (1) pxa (2) pxb (2) td = dead-band delay period (1) (1) note 1: at this time, the tmr2 register is equal to the pr2 register. 2: output signals are shown as active-high. pxa pxb fet driver fet driver v+ v- load +v - +v - standard half-bridge circuit (push-pull) downloaded from: http:///
pic18f87k22 family ds39960d-page 276 ? 2009-2011 microchip technology inc. 20.4.7 pulse steering mode in single output mode, pulse steering allows any of the pwm pins to be the modulated signal. additionally, the same pwm signal can simultaneously be available on multiple pins. once the single output mode is selected (ccpxm<3:2> = 11 and pxm<1:0> = 00 of the ccpxcon register), the user firmware can bring out the same pwm signal to one, two, three or four output pins by setting the appropriate str bits (pstrxcon<3:0>), as provided in table 20-3 . while the pwm steering mode is active, the ccpxm<1:0> bits (ccpxcon<1:0>) select the pwm output polarity for the px pins. the pwm auto-shutdown operation also applies to the pwm steering mode, as described in section 20.4.4 enhanced pwm auto-shutdown mode . an auto-shutdown event will only affect pins that have pwm outputs enabled. register 20-4: eccpxdel: e nhanced pwm control register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 pxrsen pxdc6 pxdc5 pxdc4 pxdc3 pxdc2 pxdc1 pxdc0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 pxrsen: pwm restart enable bit 1 = upon auto-shutdown, the eccpxase bit clears automatically once the shutdown event goes away; the pwm restarts automatically 0 = upon auto-shutdown, eccpxase must be cleared by software to restart the pwm bit 6-0 pxdc<6:0>: pwm delay count bits pxdcn = number of f osc /4 (4 * t osc ) cycles between the scheduled time when a pwm signal should transition active and the actual time it does transition active. note: the associated tris bits must be set to output ( 0 ) to enable the pin output driver in order to see the pwm signal on the pin. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 277 pic18f87k22 family register 20-5: pstrxcon: pulse steering control ( 1 ) r/w-0 r/w-0 u-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-1 cmpl1 cmpl0 strsync strd strc strb stra bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-6 cmpl<1:0>: complementary mode output assignment steering sync bits 00 = see str 01 = pa and pb are selected as the complementary output pair 10 = pa and pc are selected as the complementary output pair 11 = pa and pd are selected as the complementary output pair bit 5 unimplemented: read as 0 bit 4 strsync: steering sync bit 1 = output steering update occurs on the next pwm period 0 = output steering update occurs at the beginning of the instruction cycle boundary bit 3 strd: steering enable bit d 1 = pxd pin has the pwm waveform with polarity control from ccpxm<1:0> 0 = pxd pin is assigned to the port pin bit 2 strc: steering enable bit c 1 = pxc pin has the pwm waveform with polarity control from ccpxm<1:0> 0 = pxc pin is assigned to the port pin bit 1 strb: steering enable bit b 1 = pxb pin has the pwm waveform with polarity control from ccpxm<1:0> 0 = pxb pin is assigned to the port pin bit 0 stra: steering enable bit a 1 = pxa pin has the pwm waveform with polarity control from ccpxm<1:0> 0 = pxa pin is assigned to the port pin note 1: the pwm steering mode is available only when the ccpxcon register bits, ccpxm<3:2> = 11 and pxm<1:0> = 00 . downloaded from: http:///
pic18f87k22 family ds39960d-page 278 ? 2009-2011 microchip technology inc. figure 20-16: simplified steering block diagram 20.4.7.1 steering synchronization the strsync bit of the pstrxcon register gives the user two choices for when the steering event will happen. when the strsync bit is 0 , the steering event will happen at the end of the instruction that writes to the pstrxcon register. in this case, the out- put signal at the px pins may be an incomplete pwm waveform. this operation is useful when the user firmware needs to immediately remove a pwm signal from the pin. when the strsync bit is 1 , the effective steering update will happen at the beginning of the next pwm period. in this case, steering on/off the pwm output will always produce a complete pwm waveform. figures 20-17 and 20-18 illustrate the timing diagrams of the pwm steering depending on the strsync setting. figure 20-17: example of steering ev ent at end of instruction (strsync = 0) figure 20-18: example of steering event at beginning of instruction (strsync = 1) 10 tris output pin (1) port data pxa signal stra (2) 10 tris output pin (1) port data strb (2) 10 tris output pin (1) port data strc (2) 10 tris output pin (1) port data strd (2) note 1: port outputs are configured as displayed when the ccpxcon register bits, pxm<1:0> = 00 and ccp1m<3:2> = 11 . 2: single pwm output requires setting at least one of the strx bits. ccpxm1 ccpxm0 ccpxm1 ccpxm0 pwm p1n = pwm strn p1 port data pwm period port data pwm port data p1n = pwm strn p1 port data downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 279 pic18f87k22 family 20.4.8 operation in power-managed modes in sleep mode, all clock sources are disabled. timer2/4/6/8 will not increment and the state of the module will not change. if the eccpx pin is driving a value, it will continue to drive that value. when the device wakes up, it will continue from this state. if two-speed start-ups are enabled, the initial start-up frequency from hf-intosc and the postscaler may not be immediately stable. in pri_idle mode, the primary clock will continue to clock the eccpx module without change. 20.4.8.1 operation with fail-safe clock monitor (fscm) if the fail-safe clock monitor (fscm) is enabled, a clock failure will force the device into the power-managed rc_run mode and the oscfif bit of the pir2 register will be set. the eccpx will then be clocked from the internal oscillator clock source, which may have a different clock frequency than the primary clock. 20.4.9 effects of a reset both power-on reset and subsequent resets will force all ports to input mode and the eccp registers to their reset states. this forces the eccp module to reset to a state compatible with previous, non-enhanced ccp modules used on other pic18 and pic16 devices. table 20-4: registers associated with eccp1/2/3 module and timer1/2/3/4/6/8/10/12 file name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif rcon ipen sboren cm ri to pd por bor pir3 tmr5gif rc2if tx2if ctmuif ccp2if ccp1if rtccif pir4 ccp10if ( 1 ) ccp9if ( 1 ) ccp8if ccp7if ccp6if ccp5if ccp4if ccp3if pie3 tmr5gie rc2ie tx2ie ctmuie ccp2ie ccp1ie rtccie pie4 ccp10ie ( 1 ) ccp9ie ( 1 ) ccp8ie ccp7ie ccp6ie ccp5ie ccp4ie ccp3ie ipr3 tmr5gip rc2ip tx2ip ctmuip ccp2ip ccp1ip rtccip ipr4 ccp10ip ( 1 ) ccp9ip ( 1 ) ccp8ip ccp7ip ccp6ip ccp5ip ccp4ip ccp3ip trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 trise trise7 trise6 trise5 trise4 trise3 trise2 trise1 trise0 trish ( 2 ) trish7 trish6 trish5 trish4 trish3 trish2 trish1 trish0 tmr1h timer1 register high byte tmr1l timer1 register low byte tmr2 timer2 register tmr3h timer3 register high byte tmr3l timer3 register low byte tmr4 timer4 register tmr6 timer6 register tmr8 timer8 register tmr10 ( 1 ) tmr10 register tmr12 ( 1 ) tmr10 register pr2 timer2 period register pr4 timer4 period register pr6 timer6 period register pr8 timer8 period register pr10 ( 1 ) timer10 period register pr12 ( 1 ) timer12 period register note 1: unimplemented on devices with a program memory of 32 kbytes (pic18f65k22 and pic 18f85k22). 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . downloaded from: http:///
pic18f87k22 family ds39960d-page 280 ? 2009-2011 microchip technology inc. t1con tmr1cs1 tmr1cs0 t1ckps1 t1ckps0 soscen t1sync rd16 tmr1on t2con t2outps3 t2outps2 t2outps1 t2outps0 tmr2on t2ckps1 t2ckps0 t3con tmr3cs1 tmr3cs0 t3ckps1 t3ckps0 soscen t3sync rd16 tmr3on t4con t4outps3 t4outps2 t4outps1 t4outps0 tmr4on t4ckps1 t4ckps0 t6con t6outps3 t6outps2 t6outps1 t6outps0 tmr6on t6ckps1 t6ckps0 t8con t8outps3 t8outps2 t8outps1 t8outps0 tmr8on t8ckps1 t8ckps0 t10con ( 1 ) t10outps3 t10outps2 t10outps1 t10outps0 tmr10on t10ckps1 t10ckps0 t12con ( 1 ) t12outps3 t12outps2 t12outps1 t12outps0 tmr12on t12ckps1 t12ckps0 ccpr1h capture/compare/pwm register 1 high byte ccpr1l capture/compare/pwm register 1 low byte ccpr2h capture/compare/pwm register 2 high byte ccpr2l capture/compare/pwm register 2 low byte ccpr3h capture/compare/pwm register 3 high byte ccpr3l capture/compare/pwm register 3 low byte ccp1con p1m1 p1m0 dc1b1 dc1b0 ccp1m3 ccp1m2 ccp1m1 ccp1m0 ccp2con p2m1 p2m0 dc2b1 dc2b0 ccp2m3 ccp2m2 ccp2m1 ccp2m0 ccp3con ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd pmd0 ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd table 20-4: registers associated with eccp1/2/3 module and timer1/2/3/4/6/8/10/12 (continued) file name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 note 1: unimplemented on devices with a program memory of 32 kbytes (pic18f65k22 and pic 18f85k22). 2: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 281 pic18f87k22 family 21.0 master synchronous serial port (mssp) module 21.1 master ssp (mssp) module overview the master synchronous serial port (mssp) module is a serial interface, useful for communicating with other peripheral or microcontroller devices. these peripheral devices may be serial eeproms, shift registers, display drivers, a/d converters, etc. the mssp module can operate in one of two modes: serial peripheral interface (spi) inter-integrated circuit? (i 2 c?) - full master mode - slave mode (with general address call) the i 2 c interface supports the following modes in hardware: master mode multi-master mode slave mode with 5-bit and 7-bit address masking (with address masking for both 10-bit and 7-bit addressing) all members of the pic18f87k22 family have two mssp modules, designated as mssp1 and mssp2. each module operates independently of the other. 21.2 control registers each mssp module has three associated control regis- ters. these include a status register (sspxstat) and two control registers (sspxcon1 and sspxcon2). the use of these registers and their individual configuration bits differ significantly depending on whether the mssp module is operated in spi or i 2 c mode. additional details are provided under the individual sections. 21.3 spi mode the spi mode allows 8 bits of data to be synchronously transmitted and received simultaneously. all four modes of spi are supported. to accomplish communication, typically three pins are used: serial data out (sdox) C rc5/sdo1 or rd4/psp4/sdo2 serial data in (sdix) C rc4/sdi1/sda1 or rd5/psp5/sdi2/sda2 serial clock (sckx) C rc3/sck1/scl1 or rd6/psp6/sck2/scl2 additionally, a fourth pin may be used when in a slave mode of operation: slave select (ssx ) C rf7/an5/ss1 or rd7/ss2 figure 21-1 shows the block diagram of the mssp module when operating in spi mode. figure 21-1: mssp block diagram (spi mode) note: throughout this section, generic refer- ences to an mssp module in any of its operating modes may be interpreted as being equally applicable to mssp1 or mssp2. register names and module i/o signals use the generic designator x to indicate the use of a numeral to distinguish a particular module when required. control bit names are not individuated. note: in devices with more than one mssp module, it is very important to pay close attention to sspxcon register names. ssp1con1 and ssp1con2 control different operational aspects of the same module, while ssp1con1 and ssp2con1 control the same features for two different modules. note: the sspxbuf register cannot be used with read-modify-write instructions, such as bcf , comf , etc. to avoid lost data in master mode, a read of the sspxbuf must be performed to clear the buffer full (bf) detect bit (sspstat<0>) between each transmission. ( ) read write internal data bus sspxsr reg sspm<3:0> bit 0 shift clock ssx control enable edge select clock select tmr2 output t osc prescaler 4, 16, 64 2 edge select 2 4 data to txx/rxx in sspxsr tris bit 2 smp:cke sdox sspxbuf reg sdix ssx sckx note: only port i/o names are used in this diagram for the sake of brevity. refer to the text for a full list of multiplexed functions. downloaded from: http:///
pic18f87k22 family ds39960d-page 282 ? 2009-2011 microchip technology inc. 21.3.1 registers each mssp module has four registers for spi mode operation. these are: msspx control register 1 (sspxcon1) msspx status register (sspxstat) serial receive/transmit buffer register (sspxbuf) msspx shift register (sspxsr) C not directly accessible sspxcon1 and sspxstat are the control and status registers in spi mode operation. the sspxcon1 register is readable and writable. the lower 6 bits of the sspxstat are read-only. the upper two bits of the sspxstat are read/write. sspxsr is the shift register used for shifting data in or out. sspxbuf is the buffer register to which data bytes are written to or read from. in receive operations, sspxsr and sspxbuf together create a double-buffered receiver. when sspxsr receives a complete byte, it is transferred to sspxbuf and the sspxif interrupt is set. during transmission, the sspxbuf is not double-buffered. a write to sspxbuf will write to both sspxbuf and sspxsr. register 21-1: sspxstat: msspx status register (spi mode) r/w-0 r/w-0 r-0 r-0 r-0 r-0 r-0 r-0 smp cke ( 1 ) d/a psr / w ua bf bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 smp: sample bit spi master mode: 1 = input data is sampled at the end of data output time 0 = input data is sampled at the middle of data output time spi slave mode: smp must be cleared when spi is used in slave mode. bit 6 cke: spi clock select bit ( 1 ) 1 = transmit occurs on the transition from active to idle clock state 0 = transmit occurs on the transition from idle to active clock state bit 5 d/a : data/address bit used in i 2 c? mode only. bit 4 p: stop bit used in i 2 c mode only. this bit is cleared when the msspx module is disabled; sspen is cleared. bit 3 s: start bit used in i 2 c mode only. bit 2 r/w : read/write information bit used in i 2 c mode only. bit 1 ua: update address bit used in i 2 c mode only. bit 0 bf: buffer full status bit (receive mode only) 1 = receive is complete, sspxbuf is full 0 = receive is not complete, sspxbuf is empty note 1: polarity of clock state is set by the ckp bit (sspxcon1<4>). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 283 pic18f87k22 family register 21-2: sspxcon1: msspx co ntrol register 1 (spi mode) r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 wcol sspov ( 1 ) sspen ( 2 ) ckp sspm3 ( 3 ) sspm2 ( 3 ) sspm1 ( 3 ) sspm0 ( 3 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 wcol: write collision detect bit 1 = the sspxbuf register is written while it is still transmitting the previous word (must be cleared in software) 0 = no collision bit 6 sspov: receive overflow indicator bit ( 1 ) spi slave mode: 1 = a new byte is received while the sspxbuf register is still holding the previous data. in case of overflow, the data in sspxsr is lost. overflow can only occur in slave mode. the user must read the sspxbuf, even if only transmitting data, to avoid setting overflow (must be cleared in software). 0 = no overflow bit 5 sspen: master synchronous serial port enable bit ( 2 ) 1 = enables serial port and configures sckx, sdox, sdix and ssx as serial port pins 0 = disables serial port and configures these pins as i/o port pins bit 4 ckp: clock polarity select bit 1 = idle state for the clock is a high level 0 = idle state for the clock is a low level bit 3-0 sspm<3:0>: master synchronous serial port mode select bits ( 3 ) 1010 = spi master mode: clock = f osc /8 0101 = spi slave mode: clock = sckx pin; ssx pin control disabled; ssx can be used as i/o pin 0100 = spi slave mode: clock = sckx pin; ssx pin control enabled 0011 = spi master mode: clock = tmr2 output/2 0010 = spi master mode: clock = f osc /64 0001 = spi master mode: clock = f osc /16 0000 = spi master mode: clock = f osc /4 note 1: in master mode, the overflow bit is not set since each new reception (and transmission) is initiated by writing to the sspxbuf register. 2: when enabled, these pins must be properly configured as inputs or outputs. 3: bit combinations not specifically listed here are either reserved or implemented in i 2 c? mode only. downloaded from: http:///
pic18f87k22 family ds39960d-page 284 ? 2009-2011 microchip technology inc. 21.3.2 operation when initializing the spi, several options need to be specified. this is done by programming the appropriate control bits (sspxcon1<5:0> and sspxstat<7:6>). these control bits allow the following to be specified: master mode (sckx is the clock output) slave mode (sckx is the clock input) clock polarity (idle state of sckx) data input sample phase (middle or end of data output time) clock edge (output data on rising/falling edge of sckx) clock rate (master mode only) slave select mode (slave mode only) each mssp module consists of a transmit/receive shift register (sspxsr) and a serial input buffer regis- ter (sspxbuf). the sspxsr shifts the data in and out of the device, msb first. the sspxbuf holds the data that was written to the sspxsr until the received data is ready. once the 8 bits of data have been received, that byte is moved to the sspxbuf register. then, the buffer full detect bit, bf (sspxstat<0>), and the interrupt flag bit, sspxif, are set. this double-buffering of the received data (sspxbuf) allows the next byte to start reception before reading the data that was just received. any write to the sspxbuf register during transmission/reception of data will be ignored and the write collision detect bit, wcol (sspxcon1<7>), will be set. user software must clear the wcol bit so that it can be determined if the following write(s) to the sspxbuf register completed successfully. when the application software is expecting to receive valid data, the sspxbuf should be read before the next byte of data to transfer is written to the sspxbuf. the buffer full bit, bf (sspxstat<0>), indicates when sspxbuf has been loaded with the received data (transmission is complete). when the sspxbuf is read, the bf bit is cleared. this data may be irrelevant if the spi is only a transmitter. generally, the mssp interrupt is used to determine when the transmission/reception has completed. if the interrupt method is not going to be used, then software polling can be done to ensure that a write collision does not occur. example 21-1 shows the loading of the sspxbuf (sspxsr) for data transmission. the sspxsr is not directly readable or writable and can only be accessed by addressing the sspxbuf register. additionally, the sspxstat register indicates the various status conditions. 21.3.3 open-drain output option the drivers for the sdox output and sckx clock pins can be optionally configured as open-drain outputs. this feature allows the voltage level on the pin to be pulled to a higher level through an external pull-up resistor, and allows the output to communicate with external circuits without the need for additional level shifters. for more information, see section 12.1.3 open-drain outputs . the open-drain output option is controlled by the ssp2od and ssp1od bits (odcon3<1:0>). setting an sspxod bit configures the sdox and sckx pins for the corresponding module for open-drain operation. example 21-1: loading the ssp1buf (ssp1sr) register note: to avoid lost data in master mode, a read of the sspxbuf must be per- formed to clear the buffer full (bf) detect bit (sspxstat<0>) between each transmission. loop btfss ssp1stat, bf ;has data been received (transmit complete)? bra loop ;no movf ssp1buf, w ;wreg reg = contents of ssp1buf movwf rxdata ;save in user ram, if data is meaningful movf txdata, w ;w reg = contents of txdata movwf ssp1buf ;new data to xmit downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 285 pic18f87k22 family 21.3.4 enabling spi i/o to enable the serial port, mssp enable bit, sspen (sspxcon1<5>), must be set. to reset or reconfigure spi mode, clear the sspen bit, re-initialize the sspxcon registers and then set the sspen bit. this configures the sdix, sdox, sckx and ssx pins as serial port pins. for the pins to behave as the serial port function, some must have their data direction bits (in the tris register) appropriately programmed as follows: sdix must have the trisc<4> or trisd<5> bit set sdox must have the trisc<5> or trisd<4> bit cleared sckx (master mode) must have the trisc<3> or trisd<6>bit cleared sckx (slave mode) must have the trisc<3> or trisd<6> bit set ssx must have the trisf<7> or trisd<7> bit set any serial port function that is not desired may be overridden by programming the corresponding data direction (tris) register to the opposite value. 21.3.5 typical connection figure 21-2 shows a typical connection between two microcontrollers. the master controller (processor 1) initiates the data transfer by sending the sckx signal. data is shifted out of both shift registers on their pro- grammed clock edge and latched on the opposite edge of the clock. both processors should be programmed to the same clock polarity (ckp), then both controllers would send and receive data at the same time. whether the data is meaningful (or dummy data) depends on the application software. this leads to three scenarios for data transmission: master sends data ? C ? slave sends dummy data master sends data ? C ? slave sends data master sends dummy data ? C ? slave sends data figure 21-2: spi master/s lave connection serial input buffer (sspxbuf) shift register (sspxsr) msb lsb sdox sdix processor 1 sckx spi master sspm<3:0> = 00xxb serial input buffer (sspxbuf) shift register (sspxsr) lsb msb sdix sdox processor 2 sckx spi slave sspm<3:0> = 010xb serial clock downloaded from: http:///
pic18f87k22 family ds39960d-page 286 ? 2009-2011 microchip technology inc. 21.3.6 master mode the master can initiate the data transfer at any time because it controls the sckx. the master determines when the slave (processor 1, figure 21-2 ) is to broadcast data by the software protocol. in master mode, the data is transmitted/received as soon as the sspxbuf register is written to. if the spi is only going to receive, the sdox output could be dis- abled (programmed as an input). the sspxsr register will continue to shift in the signal present on the sdix pin at the programmed clock rate. as each byte is received, it will be loaded into the sspxbuf register as if a normal received byte (interrupts and status bits appropriately set). this could be useful in receiver applications as a line activity monitor mode. the clock polarity is selected by appropriately programming the ckp bit (sspxcon1<4>). this, then, would give waveforms for spi communication, as shown in figure 21-3 , figure 21-5 and figure 21-6 , where the msb is transmitted first. in master mode, the spi clock rate (bit rate) is user-programmable to be one of the following: f osc /4 (or t cy ) f osc /16 (or 4 t cy ) f osc /64 (or 16 t cy ) timer2 output/2 this allows a maximum data rate (at 40 mhz) of 10.00 mbps. figure 21-3 shows the waveforms for master mode. when the cke bit is set, the sdox data is valid before there is a clock edge on sckx. the change of the input sample is shown based on the state of the smp bit. the time when the sspxbuf is loaded with the received data is shown. figure 21-3: spi mode waveform (master mode) sckx (ckp = 0 sckx (ckp = 1 sckx (ckp = 0 sckx (ckp = 1 4 clock modes input sample input sample sdix bit 7 bit 0 sdox bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 bit 7 sdix sspxif (smp = 1 ) (smp = 0 ) (smp = 1 ) cke = 1 ) cke = 0 ) cke = 1 ) cke = 0 ) (smp = 0 ) write to sspxbuf sspxsr to sspxbuf sdox bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 (cke = 0 ) (cke = 1 ) next q4 cycle after q2 ? bit 0 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 287 pic18f87k22 family 21.3.7 slave mode in slave mode, the data is transmitted and received as the external clock pulses appear on sckx. when the last bit is latched, the sspxif interrupt flag bit is set. while in slave mode, the external clock is supplied by the external clock source on the sckx pin. this external clock must meet the minimum high and low times as specified in the electrical specifications. while in sleep mode, the slave can transmit/receive data. when a byte is received, the device can be configured to wake up from sleep. 21.3.8 slave select synchronization the ssx pin allows a synchronous slave mode. the spi must be in slave mode with the ssx pin control enabled (sspxcon1<3:0> = 04h). when the ssx pin is low, transmission and reception are enabled and the sdox pin is driven. when the ssx pin goes high, the sdox pin is no longer driven, even if in the middle of a transmitted byte and becomes a floating output. external pull-up/pull-down resistors may be desirable depending on the application. when the spi module resets, the bit counter is forced to 0 . this can be done by either forcing the ssx pin to a high level or clearing the sspen bit. to emulate two-wire communication, the sdox pin can be connected to the sdix pin. when the spi needs to operate as a receiver, the sdox pin can be configured as an input. this disables transmissions from the sdox. the sdix can always be left as an input (sdix function) since it cannot create a bus conflict. figure 21-4: slave synchroniza tion waveform note: when the spi is in slave mode with the ssx pin control enabled (sspxcon1<3:0> = 0100 ), the spi module will reset if the ssx pin is set to v dd . if the spi is used in slave mode with cke set, then the ssx pin control must be enabled. sckx (ckp = 1 sckx (ckp = 0 input sample sdix bit 7 sdox bit 7 bit 6 bit 7 sspxif interrupt (smp = 0 ) cke = 0 ) cke = 0 ) (smp = 0 ) write to sspxbuf sspxsr to sspxbuf ssx flag bit 0 bit 7 bit 0 next q4 cycle after q2 ? downloaded from: http:///
pic18f87k22 family ds39960d-page 288 ? 2009-2011 microchip technology inc. figure 21-5: spi mode waveform (slave mode with cke = 0 ) figure 21-6: spi mode waveform (slave mode with cke = 1 ) sckx (ckp = 1 sckx (ckp = 0 input sample sdix bit 7 sdox bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 sspxif interrupt (smp = 0 ) cke = 0 ) cke = 0 ) (smp = 0 ) write to sspxbuf sspxsr to sspxbuf ssx flag optional next q4 cycle after q2 ? bit 0 sckx (ckp = 1 sckx (ckp = 0 input sample sdix bit 7 bit 0 sdox bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 sspxif interrupt (smp = 0 ) cke = 1 ) cke = 1 ) (smp = 0 ) write to sspxbuf sspxsr to sspxbuf ssx flag not optional next q4 cycle after q2 ? downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 289 pic18f87k22 family 21.3.9 operation in power-managed modes in spi master mode, module clocks may be operating at a different speed than when in full-power mode. in the case of sleep mode, all clocks are halted. in idle modes, a clock is provided to the peripherals. that clock can be from the primary clock source, the secondary clock (sosc oscillator) or the intosc source. see section 3.3 clock sources and oscillator switching for additional information. in most cases, the speed that the master clocks spi data is not important; however, this should be evaluated for each system. if mssp interrupts are enabled, they can wake the con- troller from sleep mode, or one of the idle modes, when the master completes sending data. if an exit from sleep or idle mode is not desired, mssp interrupts should be disabled. if the sleep mode is selected, all module clocks are halted and the transmission/reception will remain in that state until the device wakes. after the device returns to run mode, the module will resume transmitting and receiving data. in spi slave mode, the spi transmit/receive shift register operates asynchronously to the device. this allows the device to be placed in any power-managed mode and data to be shifted into the spi transmit/receive shift register. when all 8 bits have been received, the mssp interrupt flag bit will be set, and if enabled, will wake the device. 21.3.10 effects of a reset a reset disables the mssp module and terminates the current transfer. 21.3.11 bus mode compatibility table 21-1 shows the compatibility between the standard spi modes and the states of the ckp and cke control bits. table 21-1: spi bus modes there is also an smp bit which controls when the data is sampled. 21.3.12 spi clock speed and module interactions because mssp1 and mssp2 are independent modules, they can operate simultaneously at different data rates. setting the sspm<3:0> bits of the sspxcon1 register determines the rate for the corresponding module. an exception is when both modules use timer2 as a time base in master mode. in this instance, any changes to the timer2 modules operation will affect both mssp modules equally. if different bit rates are required for each module, the user should select one of the other three time base options for one of the modules. standard spi mode terminology control bits state ckp cke 0, 0 0 1 0, 1 0 0 1, 0 1 1 1, 1 1 0 downloaded from: http:///
pic18f87k22 family ds39960d-page 290 ? 2009-2011 microchip technology inc. table 21-2: registers associat ed with spi operation name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir2 oscfif ssp2if bcl2if bcl1if hlvdif tmr3if tmr3gif pie2 oscfie ssp2ie bcl2ie bcl1ie hlvdie tmr3ie tmr3gie ipr2 oscfip ssp2ip bcl2ip bcl1ip hlvdip tmr3ip tmr3gip pir3 tmr5gif rc2if tx2if ctmuif ccp2if ccp1if rtccif pie3 tmr5gie rc2ie tx2ie ctmuie ccp2ie ccp1ie rtccie ipr3 tmr5gip rc2ip tx2ip ctmuip ccp2ip ccp1ip rtccip trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 trisd trisd7 trisd6 trisd5 trisd4 trisd3 trisd2 trisd1 trisd0 trisf trisf7 trisf6 trisf5 trisf4 trisf3 trisf2 trisf1 ssp1buf mssp1 receive buffer/transmit register ssp1con1 wcol sspov sspen ckp sspm3 sspm2 sspm1 sspm0 ssp1con2 gcen ackstat ackdt acken rcen pen rsen sen ssp1stat smp cke d/a p s r/w ua bf ssp2con1 wcol sspov sspen ckp sspm3 sspm2 sspm1 sspm0 ssp2con2 gcen ackstat ackdt acken rcen pen rsen sen ssp2stat smp cke d/a p s r/w ua bf ssp2buf mssp2 receive buffer/transmit register odcon1 ssp1od ccp2od ccp1od ssp2od pmd0 ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd legend: shaded cells are not used by the mssp module in spi mode. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 291 pic18f87k22 family 21.4 i 2 c mode the mssp module in i 2 c mode fully implements all master and slave functions (including general call support), and provides interrupts on start and stop bits in hardware to determine a free bus (multi-master function). the mssp module implements the standard mode specifications, as well as 7-bit and 10-bit addressing. two pins are used for data transfer: serial clock (sclx) C rc3/sck1/scl1 or rd6/sck2/scl2 serial data (sdax) C rc4/sdi1/sda1 or rd5/sdi2/sda2 the user must configure these pins as inputs by setting the associated tris bits. figure 21-7: mssp block diagram (i 2 c? mode) 21.4.1 registers the mssp module has seven registers for i 2 c operation. these are: msspx control register 1 (sspxcon1) msspx control register 2 (sspxcon2) msspx status register (sspxstat) serial receive/transmit buffer register (sspxbuf) msspx shift register (sspxsr) C not directly accessible msspx address register (sspxadd) i 2 c slave address mask register (sspxmsk) sspxcon1, sspxcon2 and sspxstat are the control and status registers in i 2 c mode operation. the sspxcon1 and sspxcon2 registers are readable and writable. the lower 6 bits of the sspxstat are read-only. the upper two bits of the sspxstat are read/write. sspxsr is the shift register used for shifting data in or out. sspxbuf is the buffer register to which data bytes are written to or read from. sspxadd contains the slave device address when the mssp is configured in i 2 c slave mode. when the mssp is configured in master mode, the lower seven bits of sspxadd act as the baud rate generator reload value. sspxmsk holds the slave address mask value when the module is configured for 7-bit address masking mode. while it is a separate register, it shares the same sfr address as sspxadd; it is only accessible when the sspm<3:0> bits are specifically set to permit access. additional details are provided in section 21.4.3.4 7-bit address masking mode . in receive operations, sspxsr and sspxbuf together, create a double-buffered receiver. when sspxsr receives a complete byte, it is transferred to sspxbuf and the sspxif interrupt is set. during transmission, the sspxbuf is not double-buffered. a write to sspxbuf will write to both sspxbuf and sspxsr. read write sspxsr reg match detect sspxadd reg sspxbuf reg internal data bus addr match set, reset s, p bits (sspxstat reg) shift clock msb lsb note: only port i/o names are used in this diagram for the sake of brevity. refer to the text for a full list of multiplexed functions. sclx sdax start and stop bit detect address mask downloaded from: http:///
pic18f87k22 family ds39960d-page 292 ? 2009-2011 microchip technology inc. register 21-3: sspxstat: msspx status register (i 2 c? mode) r/w-0 r/w-0 r-0 r-0 r-0 r-0 r-0 r-0 smp cke d/a p ( 1 ) s ( 1 ) r/w ( 2 , 3 ) ua bf bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 smp: slew rate control bit in master or slave mode: 1 = slew rate control is disabled for standard speed mode (100 khz and 1 mhz) 0 = slew rate control is enabled for high-speed mode (400 khz) bit 6 cke: smbus select bit in master or slave mode: 1 = enable smbus-specific inputs 0 = disable smbus-specific inputs bit 5 d/a : data/address bit in master mode: reserved. in slave mode: 1 = indicates that the last byte received or transmitted was data 0 = indicates that the last byte received or transmitted was address bit 4 p: stop bit ( 1 ) 1 = indicates that a stop bit has been detected last 0 = stop bit was not detected last bit 3 s: start bit ( 1 ) 1 = indicates that a start bit has been detected last 0 = start bit was not detected last bit 2 r/w : read/write information bit ( 2 , 3 ) in slave mode: 1 = read 0 = write in master mode: 1 = transmit is in progress 0 = transmit is not in progress bit 1 ua: update address bit (10-bit slave mode only) 1 = indicates that the user needs to update the address in the sspxadd register 0 = address does not need to be updated bit 0 bf: buffer full status bit in transmit mode: 1 = sspxbuf is full 0 = sspxbuf is empty in receive mode: 1 = sspxbuf is full (does not include the ack and stop bits) 0 = sspxbuf is empty (does not include the ack and stop bits) note 1: this bit is cleared on reset and when sspen is cleared. 2: this bit holds the r/w bit information following the last address match. this bit is only valid from the address match to the next start bit, stop bit or not ack bit. 3: oring this bit with sen, rsen, pen, rcen or acken w ill indicate if the msspx is in active mode. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 293 pic18f87k22 family register 21-4: sspxcon1: msspx control register 1 (i 2 c? mode) r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 wcol sspov sspen ( 1 ) ckp sspm3 ( 2 ) sspm2 ( 2 ) sspm1 ( 2 ) sspm0 ( 2 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 wcol: write collision detect bit in master transmit mode: 1 = a write to the sspxbuf register was attempted while the i 2 c conditions were not valid for a transmission to be started (must be cleared in software) 0 = no collision in slave transmit mode: 1 = the sspxbuf register is written while it is still transmitting the previous word (must be cleared in software) 0 = no collision in receive mode (master or slave modes): this is a dont care bit. bit 6 sspov: receive overflow indicator bit in receive mode: 1 = a byte is received while the sspxbuf register is still holding the previous byte (must be cleared in software) 0 = no overflow in transmit mode: this is a dont care bit in transmit mode. bit 5 sspen: master synchronous serial port enable bit ( 1 ) 1 = enables the serial port and configures the sdax and sclx pins as the serial port pins 0 = disables serial port and configures these pins as i/o port pins bit 4 ckp: sckx release control bit in slave mode: 1 = releases clock 0 = holds clock low (clock stretch), used to ensure data setup time in master mode: unused in this mode. bit 3-0 sspm<3:0>: master synchronous serial port mode select bits ( 2 ) 1111 = i 2 c slave mode: 10-bit address with start and stop bit interrupts enabled 1110 = i 2 c slave mode: 7-bit address with start and stop bit interrupts enabled 1011 = i 2 c firmware controlled master mode (slave idle) 1001 = load sspmsk register at sspxadd sfr address ( 3 , 4 ) 1000 = i 2 c master mode: clock = f osc /(4 * (sspxadd + 1)) 0111 = i 2 c slave mode: 10-bit address 0110 = i 2 c slave mode: 7-bit address note 1: when enabled, the sdax and sclx pins must be configured as inputs. 2: bit combinations not specifically listed here are either reserved or implemented in spi mode only. 3: when sspm<3:0> = 1001 , any reads or writes to the sspxadd sfr address actually accesses the sspxmsk register. 4: this mode is only available when 7-bit address masking mode is selected (msspmsk configuration bit is 1 ). downloaded from: http:///
pic18f87k22 family ds39960d-page 294 ? 2009-2011 microchip technology inc. register 21-5: sspxcon2: msspx control register 2 (i 2 c? master mode) r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 gcen ackstat ackdt ( 1 ) acken ( 2 ) rcen ( 2 ) pen ( 2 ) rsen ( 2 ) sen ( 2 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 gcen: general call enable bit unused in master mode. bit 6 ackstat: acknowledge status bit (master transmit mode only) 1 = acknowledge was not received from slave 0 = acknowledge was received from slave bit 5 ackdt: acknowledge data bit (master receive mode only) ( 1 ) 1 = not acknowledge 0 = acknowledge bit 4 acken: acknowledge sequence enable bit ( 2 ) 1 = initiates acknowledge sequence on sdax and sclx pins and transmits ackdt data bit. automatically cleared by hardware. 0 = acknowledge sequence is idle bit 3 rcen: receive enable bit (master receive mode only) ( 2 ) 1 = enables receive mode for i 2 c? 0 = receive is idle bit 2 pen: stop condition enable bit ( 2 ) 1 = initiates stop condition on sdax and sclx pins. automatically cleared by hardware. 0 = stop condition is idle bit 1 rsen: repeated start condition enable bit ( 2 ) 1 = initiates repeated start condition on sdax and sclx pins. automatically cleared by hardware. 0 = repeated start condition is idle bit 0 sen: start condition enable bit ( 2 ) 1 = initiates start condition on sdax and sclx pins. automatically cleared by hardware. 0 = start condition is idle note 1: value that will be transmitted when the user initiates an acknowledge sequence at the end of a receive. 2: if the i 2 c module is active, these bits may not be set (no spooling) and the sspxbuf may not be written (or writes to the sspxbuf are disabled). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 295 pic18f87k22 family register 21-6: sspxcon2: msspx control register 2 (i 2 c? slave mode) register 21-7: sspxmsk: i 2 c? slave address mask register (7-bit masking mode) ( 1 ) r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 gcen ackstat ackdt ( 1 ) acken ( 1 ) rcen ( 1 ) pen ( 1 ) rsen ( 1 ) sen ( 1 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 gcen: general call enable bit 1 = enables interrupt when a general call address (0000h) is received in the sspxsr 0 = general call address is disabled bit 6 ackstat: acknowledge status bit unused in slave mode. bit 5 ackdt: acknowledge data bit (master receive mode only) ( 1 ) 1 = not acknowledge 0 = acknowledge bit 4 acken: acknowledge sequence enable bit ( 1 ) 1 = initiates acknowledge sequence on sdax and sclx pins and transmits ackdt data bit. automatically cleared by hardware. 0 = acknowledge sequence is idle bit 3 rcen: receive enable bit (master receive mode only) ( 1 ) 1 = enables receive mode for i 2 c 0 = receive is idle bit 2 pen: stop condition enable bit ( 1 ) 1 = initiates stop condition on sdax and sclx pins. automatically cleared by hardware. 0 = stop condition is idle bit 1 rsen: repeated start condition enable bit ( 1 ) 1 = initiates repeated start condition on sdax and sclx pins. automatically cleared by hardware. 0 = repeated start condition is idle bit 0 sen: stretch enable bit ( 1 ) 1 = clock stretching is enabled for both slave transmit and slave receive (stretch enabled) 0 = clock stretching is disabled note 1: if the i 2 c module is active, this bit may not be set (no spooling) and the sspxbuf may not be written (or writes to the sspxbuf are disabled). r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 msk7 msk6 msk5 msk4 msk3 msk2 msk1 msk0 ( 2 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-0 msk<7:0>: slave address mask select bit 1 = masking of corresponding bit of sspxadd is enabled 0 = masking of corresponding bit of sspxadd is disabled note 1: this register shares the same sfr address as sspxadd and is only addressable in select msspx operating modes. see section 21.4.3.4 7-bit address masking mode for more details. 2: msk0 is not used as a mask bit in 7-bit addressing. downloaded from: http:///
pic18f87k22 family ds39960d-page 296 ? 2009-2011 microchip technology inc. 21.4.2 operation the mssp module functions are enabled by setting the mssp enable bit, sspen (sspxcon1<5>). the sspxcon1 register allows control of the i 2 c operation. four mode selection bits (sspxcon1<3:0>) allow one of the following i 2 c modes to be selected: i 2 c master mode, clock i 2 c slave mode (7-bit address) i 2 c slave mode (10-bit address) i 2 c slave mode (7-bit address) with start and stop bit interrupts enabled i 2 c slave mode (10-bit address) with start and stop bit interrupts enabled i 2 c firmware controlled master mode, slave is idle selection of any i 2 c mode with the sspen bit set forces the sclx and sdax pins to be open-drain, provided these pins are programmed as inputs by setting the appropriate trisc or trisd bits. to ensure proper operation of the module, pull-up resistors must be provided externally to the sclx and sdax pins. 21.4.3 slave mode in slave mode, the sclx and sdax pins must be configured as inputs (trisc<4:3> set). the mssp module will override the input state with the output data when required (slave-transmitter). the i 2 c slave mode hardware will always generate an interrupt on an address match. address masking will allow the hardware to generate an interrupt for more than one address (up to 31 in 7-bit addressing and up to 63 in 10-bit addressing). through the mode select bits, the user can also choose to interrupt on start and stop bits. when an address is matched, or the data transfer after an address match is received, the hardware auto- matically will generate the acknowledge (ack ) pulse and load the sspxbuf register with the received value currently in the sspxsr register. any combination of the following conditions will cause the mssp module not to give this ack pulse: the buffer full bit, bf (sspxstat<0>), was set before the transfer was received. the overflow bit, sspov (sspxcon1<6>), was set before the transfer was received. in this case, the sspxsr register value is not loaded into the sspxbuf, but bit, sspxif, is set. the bf bit is cleared by reading the sspxbuf register, while bit, sspov, is cleared through software. the sclx clock input must have a minimum high and low for proper operation. the high and low times of the i 2 c specification, as well as the requirement of the mssp module, are shown in timing parameter 100 and parameter 101. 21.4.3.1 addressing once the mssp module has been enabled, it waits for a start condition to occur. following the start condition, the 8 bits are shifted into the sspxsr register. all incoming bits are sampled with the rising edge of the clock (sclx) line. the value of register, sspxsr<7:1>, is compared to the value of the sspxadd register. the address is compared on the falling edge of the eighth clock (sclx) pulse. if the addresses match and the bf and sspov bits are clear, the following events occur: 1. the sspxsr register value is loaded into the sspxbuf register. 2. the buffer full bit, bf, is set. 3. an ack pulse is generated. 4. the mssp interrupt flag bit, sspxif, is set (and an interrupt is generated, if enabled) on the falling edge of the ninth sclx pulse. in 10-bit addressing mode, two address bytes need to be received by the slave. the five most significant bits (msbs) of the first address byte specify if this is a 10-bit address. the r/w (sspxstat<2>) bit must specify a write so the slave device will receive the second address byte. for a 10-bit address, the first byte would equal 11110 a9 a8 0 , where a9 and a8 are the two msbs of the address. the sequence of events for 10-bit addressing is as follows, with steps 7 through 9 for the slave-transmitter: 1. receive first (high) byte of address (bits, sspxif, bf and ua, are set on address match). 2. update the sspxadd register with second (low) byte of address (clears bit, ua, and releases the sclx line). 3. read the sspxbuf register (clears bit, bf) and clear flag bit, sspxif. 4. receive second (low) byte of address (bits, sspxif, bf and ua, are set). 5. update the sspxadd register with the first (high) byte of address. if match releases sclx line, this will clear bit, ua. 6. read the sspxbuf register (clears bit, bf) and clear flag bit, sspxif. 7. receive repeated start condition. 8. receive first (high) byte of address (bits, sspxif and bf, are set). 9. read the sspxbuf register (clears bit, bf) and clear flag bit, sspxif. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 297 pic18f87k22 family 21.4.3.2 address masking modes masking an address bit causes that bit to become a dont care. when one address bit is masked, two addresses will be acknowledged and cause an interrupt. it is possible to mask more than one address bit at a time, which greatly expands the number of addresses acknowledged. the i 2 c slave behaves the same way whether address masking is used or not. however, when address masking is used, the i 2 c slave can acknowledge multiple addresses and cause interrupts. when this occurs, it is necessary to determine which address caused the interrupt by checking the sspxbuf. the pic18f87k22 family of devices is capable of using two different address masking modes in i 2 c slave operation: 5-bit address masking and 7-bit address masking. the masking mode is selected at device configuration using the msspmsk configuration bit. the default device configuration is 7-bit address masking. both masking modes, in turn, support address masking of 7-bit and 10-bit addresses. the combination of masking modes and addresses provides different ranges of acknowledgable addresses for each combination. while both masking modes function in roughly the same manner, the way they use address masks are different. 21.4.3.3 5-bit address masking mode as the name implies, 5-bit address masking mode uses an address mask of up to 5 bits to create a range of addresses to be acknowledged, using bits, 5 through 1, of the incoming address. this allows the module to acknowledge up to 31 addresses when using 7-bit addressing, or 63 addresses with 10-bit addressing (see example 21-2 ). this masking mode is selected when the msspmsk configuration bit is programmed ( 0 ). the address mask in this mode is stored in the sspxcon2 register, which stops functioning as a con- trol register in i 2 c slave mode ( register 21-6 ). in 7-bit address masking mode, address mask bits, admsk<5:1> (sspxcon2<5:1>), mask the corre- sponding address bits in the sspxadd register. for any admsk bits that are set (admsk = 1 ), the cor- responding address bit is ignored (sspxadd = x ). for the module to issue an address acknowledge, it is sufficient to match only on addresses that do not have an active address mask. in 10-bit address masking mode, bits, admsk<5:2>, mask the corresponding address bits in the sspxadd register. in addition, admsk1 simultaneously masks the two lsbs of the address (sspxadd<1:0>). for any admsk bits that are active (admsk = 1 ), the cor- responding address bit is ignored (spxadd = x ). also note, that although in 10-bit address masking mode, the upper address bits reuse part of the sspxadd register bits. the address mask bits do not interact with those bits; they only affect the lower address bits. example 21-2: address masking examples in 5-bit masking mode note 1: admsk1 masks the two least significant bits of the address. 2: the two most significant bits of the address are not affected by address masking. 7-bit addressing: sspxadd<7:1>= a0h ( 1010000 ) (sspxadd<0> is assumed to be 0 ) admsk<5:1> = 00111 addresses acknowledged: a0h, a2h, a4h, a6h, a8h, aah, ach, aeh 10-bit addressing: sspxadd<7:0> = a0h ( 10100000 ) (the two msb of the address are ignored in this example, since they are not affected by masking) admsk<5:1> = 00111 addresses acknowledged: a0h, a1h, a2h, a3h, a4h, a5h, a6h, a7h, a8h, a9h, aah, abh, ach, adh, aeh, afh downloaded from: http:///
pic18f87k22 family ds39960d-page 298 ? 2009-2011 microchip technology inc. 21.4.3.4 7-bit address masking mode unlike 5-bit masking, 7-bit address masking mode uses a mask of up to 8 bits (in 10-bit addressing) to define a range of addresses that can be acknowl- edged, using the lowest bits of the incoming address. this allows the module to acknowledge up to 127 different addresses with 7-bit addressing, or 255 with 10-bit addressing (see example 21-3 ). this mode is the default configuration of the module, which is selected when msspmsk is unprogrammed ( 1 ). the address mask for 7-bit address masking mode is stored in the sspxmsk register, instead of the sspxcon2 register. sspxmsk is a separate hard- ware register within the module, but it is not directly addressable. instead, it shares an address in the sfr space with the sspxadd register. to access the sspxmsk register, it is necessary to select mssp mode, 1001 (sspxcon1<3:0> = 1001 ) and then read or write to the location of sspxadd. to use 7-bit address masking mode, it is necessary to initialize sspxmsk with a value before selecting the i 2 c slave addressing mode. thus, the required sequence of events is: 1. select sspxmsk access mode (sspxcon2<3:0> = 1001 ). 2. write the mask value to the appropriate sspadd register address (fc8h for mssp1, f6eh for mssp2). 3. set the appropriate i 2 c slave mode (sspxcon2<3:0> = 0111 for 10-bit addressing, 0110 for 7-bit addressing). setting or clearing mask bits in sspxmsk behaves in the opposite manner of the admsk bits in 5-bit address masking mode. that is, clearing a bit in sspxmsk causes the corresponding address bit to be masked; setting the bit requires a match in that position. sspxmsk resets to all 1 s upon any reset condition and, therefore, has no effect on the standard mssp operation until written with a mask value. with 7-bit addressing, sspxmsk<7:1> bits mask the corresponding address bits in the sspxadd register. for any sspxmsk bits that are active (sspxmsk = 0 ), the corresponding sspxadd address bit is ignored (sspxadd = x ). for the module to issue an address acknowledge, it is sufficient to match only on addresses that do not have an active address mask. with 10-bit addressing, sspxmsk<7:0> bits mask the corresponding address bits in the sspxadd register. for any sspxmsk bits that are active (= 0 ), the corre- sponding sspxadd address bit is ignored (sspxadd = x ). example 21-3: address masking examples in 7-bit masking mode note: the two most significant bits of the address are not affected by address masking. 7-bit addressing: sspxadd<7:1> = 1010 000 sspxmsk<7:1> = 1111 001 addresses acknowledged = ach, a8h, a4h, a0h 10-bit addressing: sspxadd<7:0> = 1010 0000 (the two msb are ignored in this example since they are not affected) sspxmsk<5:1> = 1111 0011 addresses acknowledged = ach, a8h, a4h, a0h downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 299 pic18f87k22 family 21.4.3.5 reception when the r/w bit of the address byte is clear and an address match occurs, the r/w bit of the sspxstat register is cleared. the received address is loaded into the sspxbuf register and the sdax line is held low (ack ). when the address byte overflow condition exists, then the no acknowledge (ack ) pulse is given. an overflow condition is defined as either bit, bf (sspxstat<0>), is set or bit, sspov (sspxcon1<6>), is set. an mssp interrupt is generated for each data transfer byte. the interrupt flag bit, sspxif, must be cleared in software. the sspxstat register is used to determine the status of the byte. if sen is enabled (sspxcon2<0> = 1 ), sclx will be held low (clock stretch) following each data transfer. the clock must be released by setting bit, ckp (sspxcon1<4>). see section 21.4.4 clock stretching for more details. 21.4.3.6 transmission when the r/w bit of the incoming address byte is set and an address match occurs, the r/w bit of the sspxstat register is set. the received address is loaded into the sspxbuf register. the ack pulse will be sent on the ninth bit and pin sclx is held low regard- less of sen (see section 21.4.4 clock stretching for more details). by stretching the clock, the master will be unable to assert another clock pulse until the slave is done preparing the transmit data. the transmit data must be loaded into the sspxbuf register which also loads the sspxsr register. then, pin sclx should be enabled by setting bit, ckp (sspxcon1<4>). the eight data bits are shifted out on the falling edge of the sclx input. this ensures that the sdax signal is valid during the sclx high time ( figure 21-10 ). the ack pulse from the master-receiver is latched on the rising edge of the ninth sclx input pulse. if the sdax line is high (not ack ), then the data transfer is complete. in this case, when the ack is latched by the slave, the slave logic is reset and the slave monitors for another occurrence of the start bit. if the sdax line was low (ack ), the next transmit data must be loaded into the sspxbuf register. again, pin sclx must be enabled by setting bit, ckp. an mssp interrupt is generated for each data transfer byte. the sspxif bit must be cleared in software and the sspxstat register is used to determine the status of the byte. the sspxif bit is set on the falling edge of the ninth clock pulse. downloaded from: http:///
pic18f87k22 family ds39960d-page 300 ? 2009-2011 microchip technology inc. figure 21-8: i 2 c? slave mode timing with sen = 0 (reception, 7-bit address) sdax sclx sspxif (pir1<3> or pir3<7>) bf (sspxstat<0>) sspov (sspxcon1<6>) s 1 2 34 567 89 1 2 34 5 67 89 1 23 45 7 89 p a7 a6 a5 a4 a3 a2 a1 d7 d6 d5 d4 d3 d2 d1 d0 d7 d6 d5 d4 d3 d1 d0 ack receiving data ack receiving data r/w = 0 ack receiving address cleared in software sspxbuf is read bus master terminates transfer sspov is set because sspxbuf is still full. ack is not sent. d2 6 ckp (sspxcon<4>) (ckp does not reset to 0 when sen = 0 ) downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 301 pic18f87k22 family figure 21-9: i 2 c? slave mode timing with sen = 0 and admsk<5:1> = 01011 (reception, 7-bit address) sdax sclx sspxif (pir1<3> or pir3<7>) bf (sspxstat<0>) sspov (sspxcon1<6>) s 12345678912345678912345 789 p a7 a6 a5 x a3 x x d7d6d5d4d3d2d1 d0 d7d6d5d4d3 d1d0 ack receiving data ack receiving data r/w = 0 ack receiving address cleared in software sspxbuf is read bus master terminates transfer sspov is set because sspxbuf is still full. ack is not sent. d2 6 ckp (sspxcon<4>) (ckp does not reset to 0 when sen = 0 ) note 1: x = dont care (i.e., address bit can either be a 1 or a 0 ). 2: in this example, an address equal to a7.a6.a5.x.a3.x.x will be acknowledged and cause an in terrupt. downloaded from: http:///
pic18f87k22 family ds39960d-page 302 ? 2009-2011 microchip technology inc. figure 21-10: i 2 c? slave mode timing (transmission, 7-bit address) sdax sclx bf (sspxstat<0>) a6 a5 a4 a3 a2 a1 d6 d5 d4 d3 d2 d1 d0 1 2 3 4 5 6 7 8 2 3 4 5 6 7 8 9 sspxbuf is written in software cleared in software data in sampled s ack transmitting data r/w = 1 ack receiving address a7 d7 9 1 d6 d5 d4 d3 d2 d1 d0 2 3 4 5 6 7 8 9 sspxbuf is written in software cleared in software from sspxif isr transmitting data d7 1 ckp (sspxcon<4>) p ack ckp is set in software ckp is set in software sclx held low while cpu responds to sspxif sspxif (pir1<3> or pir3<7>) from sspxif isr clear by reading downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 303 pic18f87k22 family figure 21-11: i 2 c? slave mode timing with sen = 0 and admsk<5:1> = 01001 (reception, 10-bit address) sdax sclx sspxif (pir1<3> or pir3<7>) bf (sspxstat<0>) s 123456789 123456789 12345 789 p 1 1 1 1 0 a9 a8 a7 a6 a5 x a3 a2 x x d7 d6 d5 d4 d3 d1 d0 receive data byte ack r/w = 0 ack receive first byte of address cleared in software d2 6 cleared in software receive second byte of address cleared by hardware when sspxadd is updated with low byte of address ua (sspxstat<1>) clock is held low until update of sspxadd has taken place ua is set indicating that the sspxadd needs to be updated ua is set indicating that sspxadd needs to be updated cleared by hardware when sspxadd is updated with high byte of address sspxbuf is written with contents of sspxsr dummy read of sspxbuf to clear bf flag ack ckp (sspxcon<4>) 12345 789 d7 d6 d5 d4 d3 d1 d0 receive data byte bus master terminates transfer d2 6 ack cleared in software cleared in software sspov (sspxcon1<6>) sspov is set because sspxbuf is still full. ack is not sent. (ckp does not reset to 0 when sen = 0 ) clock is held low until update of sspxadd has taken place note 1: x = dont care (i.e., address bit can either be a 1 or a 0 ). 2: in this example, an address equal to a9.a8.a7.a6.a5 .x.a3.a2.x.x will be acknowl edged and cause an interrupt. 3: note that the most significant bits of the address are not affected by the bit masking. downloaded from: http:///
pic18f87k22 family ds39960d-page 304 ? 2009-2011 microchip technology inc. figure 21-12: i 2 c? slave mode timing with sen = 0 (reception, 10-bit address) sdax sclx sspxif (pir1<3> or pir3<7>) bf (sspxstat<0>) s 123456789 123456789 12345 789 p 1 1 1 1 0 a9a8 a7 a6a5 a4a3a2a1 a0 d7 d6d5d4d3 d1d0 receive data byte ack r/w = 0 ack receive first byte of address cleared in software d2 6 cleared in software receive second byte of address cleared by hardware when sspxadd is updated with low byte of address ua (sspxstat<1>) clock is held low until update of sspxadd has taken place ua is set indicating that the sspxadd needs to be updated ua is set indicating that sspxadd needs to be updated cleared by hardware when sspxadd is updated with high byte of address sspxbuf is written with contents of sspxsr dummy read of sspxbuf to clear bf flag ack ckp (sspxcon<4>) 12345 789 d7 d6 d5 d4 d3 d1 d0 receive data byte bus master terminates transfer d2 6 ack cleared in software cleared in software sspov (sspxcon1<6>) sspov is set because sspxbuf is still full. ack is not sent. (ckp does not reset to 0 when sen = 0 ) clock is held low until update of sspxadd has taken place downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 305 pic18f87k22 family figure 21-13: i 2 c? slave mode timing (tra nsmission, 10-bit address) sdax sclx sspxif (pir1<3> or pir3<7>) bf (sspxstat<0>) s 1234 5 6789 1 2345 678 9 12345 7 89 p 1 1 1 1 0 a9a8 a7 a6a5a4a3a2a1a0 1 1 1 1 0 a8 r/w = 1 ack ack r/w = 0 ack receive first byte of address cleared in software bus master terminates transfer a9 6 receive second byte of address cleared by hardware when sspxadd is updated with low byte of address ua (sspxstat<1>) clock is held low until update of sspxadd has taken place ua is set indicating that the sspxadd needs to be updated ua is set indicating that sspxadd needs to be updated cleared by hardware when sspxadd is updated with high byte of address. sspxbuf is written with contents of sspxsr dummy read of sspxbuf to clear bf flag receive first byte of address 12345 789 d7 d6 d5 d4 d3 d1 ack d2 6 transmitting data byte d0 dummy read of sspxbuf to clear bf flag sr cleared in software write of sspxbuf initiates transmit cleared in software completion of clears bf flag ckp (sspxcon1<4>) ckp is set in software ckp is automatically cleared in hardware, holding sclx low clock is held low until update of sspxadd has taken place data transmission clock is held low until ckp is set to 1 third address sequence bf flag is clear at the end of the downloaded from: http:///
pic18f87k22 family ds39960d-page 306 ? 2009-2011 microchip technology inc. 21.4.4 clock stretching both 7-bit and 10-bit slave modes implement automatic clock stretching during a transmit sequence. the sen bit (sspxcon2<0>) allows clock stretching to be enabled during receives. setting sen will cause the sclx pin to be held low at the end of each data receive sequence. 21.4.4.1 clock stretching for 7-bit slave receive mode (sen = 1 ) in 7-bit slave receive mode, on the falling edge of the ninth clock at the end of the ack sequence, if the bf bit is set, the ckp bit in the sspxcon1 register is automatically cleared, forcing the sclx output to be held low. the ckp bit being cleared to 0 will assert the sclx line low. the ckp bit must be set in the users isr before reception is allowed to continue. by holding the sclx line low, the user has time to service the isr and read the contents of the sspxbuf before the master device can initiate another receive sequence. this will prevent buffer overruns from occurring (see figure 21-15 ). 21.4.4.2 clock stretching for 10-bit slave receive mode (sen = 1 ) in 10-bit slave receive mode, during the address sequence, clock stretching automatically takes place but ckp is not cleared. during this time, if the ua bit is set after the ninth clock, clock stretching is initiated. the ua bit is set after receiving the upper byte of the 10-bit address and following the receive of the second byte of the 10-bit address with the r/w bit cleared to 0 . the release of the clock line occurs upon updating sspxadd. clock stretching will occur on each data receive sequence as described in 7-bit mode. 21.4.4.3 clock stretching for 7-bit slave transmit mode the 7-bit slave transmit mode implements clock stretching by clearing the ckp bit after the falling edge of the ninth clock if the bf bit is clear. this occurs regardless of the state of the sen bit. the users isr must set the ckp bit before transmis- sion is allowed to continue. by holding the sclx line low, the user has time to service the isr and load the contents of the sspxbuf before the master device can initiate another transmit sequence (see figure 21-10 ). 21.4.4.4 clock stretching for 10-bit slave transmit mode in 10-bit slave transmit mode, clock stretching is controlled during the first two address sequences by the state of the ua bit, just as it is in 10-bit slave receive mode. the first two addresses are followed by a third address sequence, which contains the high-order bits of the 10-bit address and the r/w bit set to 1 . after the third address sequence is performed, the ua bit is not set, the module is now configured in transmit mode and clock stretching is controlled by the bf flag as in 7-bit slave transmit mode (see figure 21-13 ). note 1: if the user reads the contents of the sspxbuf before the falling edge of the ninth clock, thus clearing the bf bit, the ckp bit will not be cleared and clock stretching will not occur. 2: the ckp bit can be set in software regardless of the state of the bf bit. the user should be careful to clear the bf bit in the isr before the next receive sequence in order to prevent an overflow condition. note: if the user polls the ua bit and clears it by updating the sspxadd register before the falling edge of the ninth clock occurs, and if the user hasnt cleared the bf bit by reading the sspxbuf register before that time, then the ckp bit will still not be asserted low. clock stretching, on the basis of the state of the bf bit, only occurs during a data sequence, not an address sequence. note 1: if the user loads the contents of sspxbuf, setting the bf bit before the falling edge of the ninth clock, the ckp bit will not be cleared and clock stretching will not occur. 2: the ckp bit can be set in software regardless of the state of the bf bit. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 307 pic18f87k22 family 21.4.4.5 clock synchronization and the ckp bit when the ckp bit is cleared, the sclx output is forced to 0 . however, clearing the ckp bit will not assert the sclx output low until the sclx output is already sampled low. therefore, the ckp bit will not assert the sclx line until an external i 2 c master device has already asserted the sclx line. the sclx output will remain low until the ckp bit is set and all other devices on the i 2 c bus have deasserted sclx. this ensures that a write to the ckp bit will not violate the minimum high time requirement for sclx (see figure 21-14 ). figure 21-14: clock synchronization timing sdax sclx dx C 1 dx wr q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 sspxcon1 ckp master device deasserts clock master device asserts clock downloaded from: http:///
pic18f87k22 family ds39960d-page 308 ? 2009-2011 microchip technology inc. figure 21-15: i 2 c? slave mode timing with sen = 1 (reception, 7-bit address) sdax sclx sspxif (pir1<3> or pir3<7>) bf (sspxstat<0>) sspov (sspxcon1<6>) s 1 234 56 7 8 9 1 2345 67 89 1 23 45 7 89 p a7 a6 a5 a4 a3 a2 a1 d7 d6 d5 d4 d3 d2 d1 d0 d7 d6 d5 d4 d3 d1 d0 ack receiving data ack receiving data r/w = 0 ack receiving address cleared in software sspxbuf is read bus master terminates transfer sspov is set because sspxbuf is still full. ack is not sent. d2 6 ckp (sspxcon<4>) ckp written to 1 in if bf is cleared prior to the falling edge of the 9th clock, ckp will not be reset to 0 and no clock stretching will occur software clock is held low until ckp is set to 1 clock is not held low because buffer full bit is clear prior to falling edge of 9th clock clock is not held low because ack = 1 bf is set after falling edge of the 9th clock, ckp is reset to 0 and clock stretching occurs downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 309 pic18f87k22 family figure 21-16: i 2 c? slave mode timing with sen = 1 (reception, 10-bit address) sdax sclx sspxif (pir1<3> or pir3<7>) bf (sspxstat<0>) s 123456789 123456789 12345 789 p 1 1 1 1 0 a9a8 a7 a6a5a4a3a2a1 a0 d7d6d5d4d3 d1d0 receive data byte ack r/w = 0 ack receive first byte of address cleared in software d2 6 cleared in software receive second byte of address cleared by hardware when sspxadd is updated with low byte of address after falling edge ua (sspxstat<1>) clock is held low until update of sspxadd has taken place ua is set indicating that the sspxadd needs to be updated ua is set indicating that sspxadd needs to be updated cleared by hardware when sspxadd is updated with high byte of address after falling edge sspxbuf is written with contents of sspxsr dummy read of sspxbuf to clear bf flag ack ckp (sspxcon<4>) 12345 789 d7 d6 d5 d4 d3 d1 d0 receive data byte bus master terminates transfer d2 6 ack cleared in software cleared in software sspov (sspxcon1<6>) ckp written to 1 note: an update of the sspxadd register before the falling edge of the ninth clock will have no effect on ua and ua will remain set. note: an update of the sspxadd register before the falling edge of the ninth clock will have no effect on ua and ua will remain set. in software clock is held low until update of sspxadd has taken place of ninth clock of ninth clock sspov is set because sspxbuf is still full. ack is not sent. dummy read of sspxbuf to clear bf flag clock is held low until ckp is set to 1 clock is not held low because ack = 1 downloaded from: http:///
pic18f87k22 family ds39960d-page 310 ? 2009-2011 microchip technology inc. 21.4.5 general call address support the addressing procedure for the i 2 c bus is such that the first byte after the start condition usually determines which device will be the slave addressed by the master. the exception is the general call address which can address all devices. when this address is used, all devices should, in theory, respond with an acknowledge. the general call address is one of eight addresses reserved for specific purposes by the i 2 c protocol. it consists of all 0 s with r/w = 0 . the general call address is recognized when the general call enable bit, gcen, is enabled (sspxcon2<7> set). following a start bit detect, eight bits are shifted into the sspxsr and the address is compared against the sspxadd. it is also compared to the general call address and fixed in hardware. if the general call address matches, the sspxsr is transferred to the sspxbuf, the bf flag bit is set (eighth bit), and on the falling edge of the ninth bit (ack bit), the sspxif interrupt flag bit is set. when the interrupt is serviced, the source for the interrupt can be checked by reading the contents of the sspxbuf. the value can be used to determine if the address was device-specific or a general call address. in 10-bit addressing mode, the sspxadd is required to be updated for the second half of the address to match and the ua bit is set (sspxstat<1>). if the gen- eral call address is sampled when the gcen bit is set, while the slave is configured in 10-bit addressing mode, then the second half of the address is not necessary, the ua bit will not be set and the slave will begin receiving data after the acknowledge ( figure 21-17 ). figure 21-17: slave mode general call address sequence (7 or 10-bit addressing mode) sdax sclx s sspxif bf (sspxstat<0>) sspov (sspxcon1<6>) cleared in software sspxbuf is read r/w = 0 ack general call address address is compared to general call address gcen (sspxcon2<7>) receiving data ack 123456789123456789 d7 d6 d5 d4 d3 d2 d1 d0 after ack , set interrupt 0 1 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 311 pic18f87k22 family 21.4.6 master mode master mode is enabled by setting and clearing the appropriate sspm bits in sspxcon1, and by setting the sspen bit. in master mode, the sclx and sdax lines are manipulated by the mssp hardware if the tris bits are set. the master mode of operation is supported by interrupt generation on the detection of the start and stop conditions. the stop (p) and start (s) bits are cleared from a reset or when the mssp module is disabled. control of the i 2 c bus may be taken when the p bit is set, or the bus is idle, with both the s and p bits clear. in firmware controlled master mode, user code conducts all i 2 c bus operations based on start and stop bit conditions. once master mode is enabled, the user has six options. 1. assert a start condition on sdax and sclx. 2. assert a repeated start condition on sdax and sclx. 3. write to the sspxbuf register, initiating transmission of data/address. 4. configure the i 2 c port to receive data. 5. generate an acknowledge condition at the end of a received byte of data. 6. generate a stop condition on sdax and sclx. the following events will cause the mssp interrupt flag bit, sspxif, to be set (and mssp interrupt, if enabled): start condition stop condition data transfer byte transmitted/received acknowledge transmitted repeated start figure 21-18: mssp block diagram (i 2 c? master mode) note: the mssp module, when configured in i 2 c master mode, does not allow queueing of events. for instance, the user is not allowed to initiate a start condition and immediately write the sspxbuf register to initiate transmission before the start condition is complete. in this case, the sspxbuf will not be written to and the wcol bit will be set, indicating that a write to the sspxbuf did not occur. read write sspxsr start bit, stop bit, sspxbuf internal data bus set/reset s, p (sspxstat), wcol (sspxcon1); shift clock msb lsb sdax acknowledge generate stop bit detect write collision detect clock arbitration state counter for end of xmit/rcv sclx sclx in bus collision sdax in receive enable clock cntl clock arbitrate/wcol detect (hold off clock source) sspxadd<6:0> baud set sspxif, bclxif; reset ackstat, pen (sspxcon2) rate generator sspm<3:0> start bit detect downloaded from: http:///
pic18f87k22 family ds39960d-page 312 ? 2009-2011 microchip technology inc. 21.4.6.1 i 2 c? master mode operation the master device generates all of the serial clock pulses and the start and stop conditions. a transfer is ended with a stop condition or with a repeated start condition. since the repeated start condition is also the beginning of the next serial transfer, the i 2 c bus will not be released. in master transmitter mode, serial data is output through sdax while sclx outputs the serial clock. the first byte transmitted contains the slave address of the receiving device (7 bits) and the read/write (r/w ) bit. in this case, the r/w bit will be logic 0 . serial data is transmitted, 8 bits at a time. after each byte is transmit- ted, an acknowledge bit is received. start and stop conditions are output to indicate the beginning and the end of a serial transfer. in master receive mode, the first byte transmitted contains the slave address of the transmitting device (7 bits) and the r/w bit. in this case, the r/w bit will be logic 1 . thus, the first byte transmitted is a 7-bit slave address, followed by a 1 to indicate the receive bit. serial data is received via sdax, while sclx outputs the serial clock. serial data is received, 8 bits at a time. after each byte is received, an acknowledge bit is transmitted. start and stop conditions indicate the beginning and end of transmission. the baud rate generator, used for the spi mode operation, is used to set the sclx clock frequency for either 100 khz, 400 khz or 1 mhz i 2 c operation. see section 21.4.7 baud rate for more details. a typical transmit sequence would go as follows: 1. the user generates a start condition by setting the start enable bit, sen (sspxcon2<0>). 2. sspxif is set. the mssp module will wait the required start time before any other operation takes place. 3. the user loads the sspxbuf with the slave address to transmit. 4. address is shifted out the sdax pin until all 8 bits are transmitted. 5. the mssp module shifts in the ack bit from the slave device and writes its value into the sspxcon2 register (sspxcon2<6>). 6. the mssp module generates an interrupt at the end of the ninth clock cycle by setting the sspxif bit. 7. the user loads the sspxbuf with eight bits of data. 8. data is shifted out the sdax pin until all 8 bits are transmitted. 9. the mssp module shifts in the ack bit from the slave device and writes its value into the sspxcon2 register (sspxcon2<6>). 10. the mssp module generates an interrupt at the end of the ninth clock cycle by setting the sspxif bit. 11. the user generates a stop condition by setting the stop enable bit, pen (sspxcon2<2>). 12. interrupt is generated once the stop condition is complete. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 313 pic18f87k22 family 21.4.7 baud rate in i 2 c master mode, the baud rate generator (brg) reload value is placed in the lower 7 bits of the sspxadd register ( figure 21-19 ). when a write occurs to sspxbuf, the baud rate generator will automatically begin counting. the brg counts down to 0 and stops until another reload has taken place. the brg count is decremented twice per instruction cycle (t cy ) on the q2 and q4 clocks. in i 2 c master mode, the brg is reloaded automatically. once the given operation is complete (i.e., transmis- sion of the last data bit is followed by ack ), the internal clock will automatically stop counting and the sclx pin will remain in its last state. table 21-3 demonstrates clock rates based on instruction cycles and the brg value loaded into sspxadd. the sspxadd brg value of 0x00 is not supported. 21.4.7.1 baud rate and module interdependence because mssp1 and mssp2 are independent, they can operate simultaneously in i 2 c master mode at different baud rates. this is done by using different brg reload values for each module. because this mode derives its basic clock source from the system clock, any changes to the clock will affect both modules in the same proportion. it may be possible to change one or both baud rates back to a previous value by changing the brg reload value. figure 21-19: baud rate generato r block diagram table 21-3: i 2 c? clock rate w/brg f osc f cy f cy * 2 brg value f scl (2 rollovers of brg) 40 mhz 10 mhz 20 mhz 18h 400 khz 40 mhz 10 mhz 20 mhz 1fh 312.5 khz 40 mhz 10 mhz 20 mhz 63h 100 khz 16 mhz 4 mhz 8 mhz 09h 400 khz 16 mhz 4 mhz 8 mhz 0ch 308 khz 16 mhz 4 mhz 8 mhz 27h 100 khz 4 mhz 1 mhz 2 mhz 02h 333 khz 4 mhz 1 mhz 2 mhz 09h 100 khz 16 mhz 4 mhz 8 mhz 03h 1 mhz ( 1 ) note 1: a minimum of 16 mhz f osc is required to get 1 mhz i 2 c. sspm<3:0> brg down counter clko f osc /4 sspxadd<6:0> sspm<3:0> sclx reload control reload downloaded from: http:///
pic18f87k22 family ds39960d-page 314 ? 2009-2011 microchip technology inc. 21.4.7.2 clock arbitration clock arbitration occurs when the master, during any receive, transmit or repeated start/stop condition, deasserts the sclx pin (sclx allowed to float high). when the sclx pin is allowed to float high, the baud rate generator (brg) is suspended from counting until the sclx pin is actually sampled high. when the sclx pin is sampled high, the baud rate generator is reloaded with the contents of sspxadd<6:0> and begins counting. this ensures that the sclx high time will always be at least one brg rollover count in the event that the clock is held low by an external device ( figure 21-20 ). figure 21-20: baud rate generator timing with clock arbitration sdax sclx sclx deasserted but slave holds dx C 1 dx brg sclx is sampled high, reload takes place and brg starts its count 03h 02h 01h 00h (hold off) 03h 02h reload brg value sclx low (clock arbitration) sclx allowed to transition high brg decrements on q2 and q4 cycles downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 315 pic18f87k22 family 21.4.8 i 2 c? master mode start condition timing to initiate a start condition, the user sets the start enable bit, sen (sspxcon2<0>). if the sdax and sclx pins are sampled high, the baud rate generator is reloaded with the contents of sspxadd<6:0> and starts its count. if sclx and sdax are both sampled high when the baud rate generator times out (t brg ), the sdax pin is driven low. the action of the sdax being driven low while sclx is high is the start condi- tion and causes the s bit (sspxstat<3>) to be set. following this, the baud rate generator is reloaded with the contents of sspxadd<6:0> and resumes its count. when the baud rate generator times out (t brg ), the sen bit (sspxcon2<0>) will be automatically cleared by hardware. the baud rate generator is suspended, leaving the sdax line held low and the start condition is complete. 21.4.8.1 wcol status flag if the user writes the sspxbuf when a start sequence is in progress, the wcol bit is set and the contents of the buffer are unchanged (the write doesnt occur). figure 21-21: first start bit timing note: if, at the beginning of the start condition, the sdax and sclx pins are already sampled low, or if during the start condi- tion, the sclx line is sampled low before the sdax line is driven low, a bus collision occurs, the bus collision interrupt flag, bclxif, is set, the start condition is aborted and the i 2 c module is reset into its idle state. note: because queueing of events is not allowed, writing to the lower 5 bits of sspxcon2 is disabled until the start condition is complete. sdax sclx s t brg 1st bit 2nd bit t brg sdax = 1 , at completion of start bit, sclx = 1 write to sspxbuf occurs here t brg hardware clears sen bit t brg write to sen bit occurs here set s bit (sspxstat<3>) and sets sspxif bit downloaded from: http:///
pic18f87k22 family ds39960d-page 316 ? 2009-2011 microchip technology inc. 21.4.9 i 2 c? master mode repeated start condition timing a repeated start condition occurs when the rsen bit (sspxcon2<1>) is programmed high and the i 2 c logic module is in the idle state. when the rsen bit is set, the sclx pin is asserted low. when the sclx pin is sampled low, the baud rate generator is loaded with the contents of sspxadd<5:0> and begins counting. the sdax pin is released (brought high) for one baud rate generator count (t brg ). when the baud rate generator times out, and if sdax is sampled high, the sclx pin will be deasserted (brought high). when sclx is sampled high, the baud rate generator is reloaded with the contents of sspxadd<6:0> and begins counting. sdax and sclx must be sampled high for one t brg . this action is then followed by assertion of the sdax pin (sdax = 0 ) for one t brg while sclx is high. following this, the rsen bit (sspxcon2<1>) will be automatically cleared and the baud rate generator will not be reloaded, leaving the sdax pin held low. as soon as a start condition is detected on the sdax and sclx pins, the s bit (sspxstat<3>) will be set. the sspxif bit will not be set until the baud rate generator has timed out. immediately following the sspxif bit getting set, the user may write the sspxbuf with the 7-bit address in 7-bit mode or the default first address in 10-bit mode. after the first eight bits are transmitted and an ack is received, the user may then transmit an additional eight bits of address (10-bit mode) or eight bits of data (7-bit mode). 21.4.9.1 wcol status flag if the user writes the sspxbuf when a repeated start sequence is in progress, the wcol is set and the contents of the buffer are unchanged (the write doesnt occur). figure 21-22: repeated start co ndition waveform note 1: if rsen is programmed while any other event is in progress, it will not take effect. 2: a bus collision during the repeated start condition occurs if: sdax is sampled low when sclx goes from low-to-high. sclx goes low before sdax is asserted low. this may indicate that another master is attempting to transmit a data 1 . note: because queueing of events is not allowed, writing of the lower 5 bits of sspxcon2 is disabled until the repeated start condition is complete. sdax sclx sr = repeated start write to sspxcon2 occurs here: write to sspxbuf occurs here on falling edge of ninth clock, end of xmit at completion of start bit, hardware clears rsen bit 1st bit s bit set by hardware t brg sdax = 1 , sdax = 1 , sclx (no change). sclx = 1 and sets sspxif rsen bit set by hardware t brg t brg t brg t brg downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 317 pic18f87k22 family 21.4.10 i 2 c? master mode transmission transmission of a data byte, a 7-bit address or the other half of a 10-bit address, is accomplished by simply writing a value to the sspxbuf register. this action will set the buffer full flag bit, bf, and allow the baud rate generator to begin counting and start the next transmission. each bit of address/data will be shifted out onto the sdax pin after the falling edge of sclx is asserted (see data hold time specification parameter 106). sclx is held low for one baud rate generator rollover count (t brg ). data should be valid before sclx is released high (see data setup time specification parameter 107). when the sclx pin is released high, it is held that way for t brg . the data on the sdax pin must remain stable for that duration and some hold time after the next falling edge of sclx. after the eighth bit is shifted out (the falling edge of the eighth clock), the bf flag is cleared and the master releases sdax. this allows the slave device being addressed to respond with an ack bit during the ninth bit time if an address match occurred, or if data was received properly. the status of ack is written into the ackdt bit on the falling edge of the ninth clock. if the master receives an acknowledge, the acknowledge status bit, ackstat, is cleared; if not, the bit is set. after the ninth clock, the sspxif bit is set and the master clock (baud rate generator) is suspended until the next data byte is loaded into the sspxbuf, leaving sclx low and sdax unchanged ( figure 21-23 ). after the write to the sspxbuf, each bit of the address will be shifted out on the falling edge of sclx until all seven address bits and the r/w bit are completed. on the falling edge of the eighth clock, the master will deassert the sdax pin, allowing the slave to respond with an acknowledge. on the falling edge of the ninth clock, the master will sample the sdax pin to see if the address was recognized by a slave. the status of the ack bit is loaded into the ackstat status bit (sspxcon2<6>). following the falling edge of the ninth clock transmission of the address, the sspxif flag is set, the bf flag is cleared and the baud rate generator is turned off until another write to the sspxbuf takes place, holding sclx low and allowing sdax to float. 21.4.10.1 bf status flag in transmit mode, the bf bit (sspxstat<0>) is set when the cpu writes to sspxbuf and is cleared when all 8 bits are shifted out. 21.4.10.2 wcol status flag if the user writes the sspxbuf when a transmit is already in progress (i.e., sspxsr is still shifting out a data byte), the wcol bit is set and the contents of the buffer are unchanged (the write doesnt occur) after 2t cy after the sspxbuf write. if sspxbuf is rewritten within 2 t cy , the wcol bit is set and sspxbuf is updated. this may result in a corrupted transfer. the user should verify that the wcol bit is clear after each write to sspxbuf to ensure the transfer is correct. in all cases, wcol must be cleared in software. 21.4.10.3 ackstat status flag in transmit mode, the ackstat bit (sspxcon2<6>) is cleared when the slave has sent an acknowledge (ack = 0 ) and is set when the slave does not acknowl- edge (ack = 1 ). a slave sends an acknowledge when it has recognized its address (including a general call), or when the slave has properly received its data. 21.4.11 i 2 c? master mode reception master mode reception is enabled by programming the receive enable bit, rcen (sspxcon2<3>). the baud rate generator begins counting, and on each rollover, the state of the sclx pin changes (high-to-low/low-to-high) and data is shifted into the sspxsr. after the falling edge of the eighth clock, the receive enable flag is automatically cleared, the con- tents of the sspxsr are loaded into the sspxbuf, the bf flag bit is set, the sspxif flag bit is set and the baud rate generator is suspended from counting, holding sclx low. the mssp is now in idle state awaiting the next command. when the buffer is read by the cpu, the bf flag bit is automatically cleared. the user can then send an acknowledge bit at the end of reception by setting the acknowledge sequence enable bit, acken (sspxcon2<4>). 21.4.11.1 bf status flag in receive operation, the bf bit is set when an address or data byte is loaded into sspxbuf from sspxsr. it is cleared when the sspxbuf register is read. 21.4.11.2 sspov status flag in receive operation, the sspov bit is set when 8 bits are received into the sspxsr and the bf flag bit is already set from a previous reception. 21.4.11.3 wcol status flag if the user writes the sspxbuf when a receive is already in progress (i.e., sspxsr is still shifting in a data byte), the wcol bit is set and the contents of the buffer are unchanged (the write doesnt occur). note: the mssp module must be in an inactive state before the rcen bit is set or the rcen bit will be disregarded. downloaded from: http:///
pic18f87k22 family ds39960d-page 318 ? 2009-2011 microchip technology inc. figure 21-23: i 2 c? master mode waveform (transmission, 7 or 10-bit address) sdax sclx sspxif bf (sspxstat<0>) sen a7 a6 a5 a4 a3 a2 a1 ack = 0 d7 d6 d5 d4 d3 d2 d1 d0 ack transmitting data or second half r/w = 0 transmit address to slave 123456789 123456789 p cleared in software service routine sspxbuf is written in software from mssp interrupt after start condition, sen cleared by hardware s sspxbuf written with 7-bit address and r/w , start transmit sclx held low while cpu responds to sspxif sen = 0 of 10-bit address write sspxcon2<0> (sen = 1 ), start condition begins from slave, clear ackstat bit (sspxcon2<6>) ackstat in sspxcon2 = 1 cleared in software sspxbuf written pen r/w cleared in software downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 319 pic18f87k22 family figure 21-24: i 2 c? master mode waveform (reception, 7-bit address) p 9 8 7 6 5 d0 d1 d2 d3 d4 d5 d6 d7 s a7 a6 a5 a4 a3 a2 a1 sdax sclx 12 3 4 5 6 7 8 9 12 3 4 5 678 9 1234 bus master terminates transfer ack receiving data from slave receiving data from slave d0 d1 d2 d3 d4 d5 d6 d7 ack r/w = 1 transmit address to slave sspxif bf ack is not sent write to sspxcon2<0> (sen = 1 ), write to sspxbuf occurs here, ack from slave master configured as a receiver by programming sspxcon2<3> (rcen = 1 ) pen bit = 1 written here data shifted in on falling edge of clk cleared in software start xmit sen = 0 sspov sdax = 0 , sclx = 1 , while cpu (sspxstat<0>) ack cleared in software cleared in software set sspxif interrupt at end of receive set p bit (sspxstat<4>) and sspxif ack from master, set sspxif at end set sspxif interrupt at end of acknowledge sequence set sspxif interrupt at end of acknowledge sequence of receive set acken, start acknowledge sequence, sdax = ackdt = 1 rcen cleared automatically rcen = 1 , start next receive write to sspxcon2<4> to start acknowledge sequence, sdax = ackdt (sspxcon2<5>) = 0 rcen cleared automatically responds to sspxif acken begin start condition cleared in software sdax = ackdt = 0 last bit is shifted into sspxsr and contents are unloaded into sspxbuf cleared in software sspov is set because sspxbuf is still full downloaded from: http:///
pic18f87k22 family ds39960d-page 320 ? 2009-2011 microchip technology inc. 21.4.12 acknowledge sequence timing an acknowledge sequence is enabled by setting the acknowledge sequence enable bit, acken (sspxcon2<4>). when this bit is set, the sclx pin is pulled low and the contents of the acknowledge data bit are presented on the sdax pin. if the user wishes to gen- erate an acknowledge, then the ackdt bit should be cleared. if not, the user should set the ackdt bit before starting an acknowledge sequence. the baud rate gen- erator then counts for one rollover period (t brg ) and the sclx pin is deasserted (pulled high). when the sclx pin is sampled high (clock arbitration), the baud rate gener- ator counts for t brg ; the sclx pin is then pulled low. following this, the acken bit is automatically cleared, the baud rate generator is turned off and the mssp module then goes into an inactive state ( figure 21-25 ). 21.4.12.1 wcol status flag if the user writes the sspxbuf when an acknowledge sequence is in progress, then wcol is set and the contents of the buffer are unchanged (the write doesnt occur). 21.4.13 stop condition timing a stop bit is asserted on the sdax pin at the end of a receive/transmit by setting the stop sequence enable bit, pen (sspxcon2<2>). at the end of a receive/transmit, the sclx line is held low after the falling edge of the ninth clock. when the pen bit is set, the master will assert the sdax line low. when the sdax line is sampled low, the baud rate generator is reloaded and counts down to 0. when the baud rate generator times out, the sclx pin will be brought high and one t brg (baud rate generator rollover count) later, the sdax pin will be deasserted. when the sdax pin is sampled high while sclx is high, the p bit (sspxstat<4>) is set. a t brg later, the pen bit is cleared and the sspxif bit is set (see figure 21-26 ). 21.4.13.1 wcol status flag if the user writes the sspxbuf when a stop sequence is in progress, then the wcol bit is set and the contents of the buffer are unchanged (the write doesnt occur). figure 21-25: acknowledge sequen ce waveform figure 21-26: stop cond ition receive or transmit mode note: t brg = one baud rate generator period. sdax sclx sspxif set at acknowledge sequence starts here, write to sspxcon2, acken automatically cleared cleared in t brg t brg the end of receive 8 acken = 1 , ackdt = 0 d0 9 sspxif software sspxif set at the end of acknowledge sequence cleared in software ack sclx sdax sdax asserted low before rising edge of clock write to sspxcon2, set pen falling edge of sclx = 1 for t brg , followed by sdax = 1 for t brg 9th clock sclx brought high after t brg note: t brg = one baud rate generator period. t brg t brg after sdax sampled high. p bit (sspxstat<4>) is set t brg to set up stop condition ack p t brg pen bit (sspxcon2<2>) is cleared by hardware and the sspxif bit is set downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 321 pic18f87k22 family 21.4.14 sleep operation while in sleep mode, the i 2 c module can receive addresses or data, and when an address match or complete byte transfer occurs, wake the processor from sleep (if the mssp interrupt is enabled). 21.4.15 effects of a reset a reset disables the mssp module and terminates the current transfer. 21.4.16 multi-master mode in multi-master mode, the interrupt generation on the detection of the start and stop conditions allows the determination of when the bus is free. the stop (p) and start (s) bits are cleared from a reset or when the mssp module is disabled. control of the i 2 c bus may be taken when the p bit (sspxstat<4>) is set, or the bus is idle, with both the s and p bits clear. when the bus is busy, enabling the mssp interrupt will generate the interrupt when the stop condition occurs. in multi-master operation, the sdax line must be monitored for arbitration to see if the signal level is the expected output level. this check is performed in hardware with the result placed in the bclxif bit. the states where arbitration can be lost are: address transfer data transfer a start condition a repeated start condition an acknowledge condition 21.4.17 multi -master communication, bus collision and bus arbitration multi-master mode support is achieved by bus arbitra- tion. when the master outputs address/data bits onto the sdax pin, arbitration takes place when the master outputs a 1 on sdax, by letting sdax float high, and another master asserts a 0 . when the sclx pin floats high, data should be stable. if the expected data on sdax is a 1 and the data sampled on the sdax pin = 0 , then a bus collision has taken place. the master will set the bus collision interrupt flag, bclxif, and reset the i 2 c port to its idle state ( figure 21-27 ). if a transmit was in progress when the bus collision occurred, the transmission is halted, the bf flag is cleared, the sdax and sclx lines are deasserted and the sspxbuf can be written to. when the user services the bus collision interrupt service routine and if the i 2 c bus is free, the user can resume communication by asserting a start condition. if a start, repeated start, stop or acknowledge condition was in progress when the bus collision occurred, the con- dition is aborted, the sdax and sclx lines are deasserted and the respective control bits in the sspxcon2 register are cleared. when the user services the bus collision interrupt service routine (isr), and if the i 2 c bus is free, the user can resume communication by asserting a start condition. the master will continue to monitor the sdax and sclx pins. if a stop condition occurs, the sspxif bit will be set. a write to the sspxbuf will start the transmission of data at the first data bit regardless of where the transmitter left off when the bus collision occurred. in multi-master mode, the interrupt generation on the detection of start and stop conditions allows the determi- nation of when the bus is free. control of the i 2 c bus can be taken when the p bit is set in the sspxstat register, or the bus is idle and the s and p bits are cleared. figure 21-27: bus collision timing for transmit and acknowledge sdax sclx bclxif sdax released sdax line pulled low by another source sample sdax. while sclx is high, data doesnt match what is driven bus collision has occurred set bus collision interrupt (bclxif) by the master; by master data changes while sclx = 0 downloaded from: http:///
pic18f87k22 family ds39960d-page 322 ? 2009-2011 microchip technology inc. 21.4.17.1 bus collision during a start condition during a start condition, a bus collision occurs if: a) sdax or sclx is sampled low at the beginning of the start condition ( figure 21-28 ). b) sclx is sampled low before sdax is asserted low ( figure 21-29 ). during a start condition, both the sdax and the sclx pins are monitored. if the sdax pin is already low, or the sclx pin is already low, then all of the following occur: the start condition is aborted the bclxif flag is set the mssp module is reset to its inactive state ( figure 21-28 ) the start condition begins with the sdax and sclx pins deasserted. when the sdax pin is sampled high, the baud rate generator is loaded from sspxadd<6:0> and counts down to 0. if the sclx pin is sampled low while sdax is high, a bus collision occurs because it is assumed that another master is attempting to drive a data 1 during the start condition. if the sdax pin is sampled low during this count, the brg is reset and the sdax line is asserted early ( figure 21-30 ). if, however, a 1 is sampled on the sdax pin, the sdax pin is asserted low at the end of the brg count. the baud rate generator is then reloaded and counts down to 0. if the sclx pin is sampled as 0 during this time, a bus collision does not occur. at the end of the brg count, the sclx pin is asserted low. figure 21-28: bus collision during st art condition (sdax only) note: the reason that a bus collision is not a factor during a start condition is that no two bus masters can assert a start condition at the exact same time. therefore, one master will always assert sdax before the other. this condition does not cause a bus collision because the two masters must be allowed to arbitrate the first address following the start condition. if the address is the same, arbitration must be allowed to continue into the data portion, repeated start or stop conditions. sdax sclx sen sdax sampled low before sdax goes low before the sen bit is set. s bit and sspxif set because mssp module reset into idle state sen cleared automatically because of bus collision, s bit and sspxif set because set sen, enable start condition if sdax = 1 , sclx = 1 sdax = 0 , sclx = 1 bclxif s sspxif sdax = 0 , sclx = 1 sspxif and bclxif are cleared in software sspxif and bclxif are cleared in software set bclxif, start condition, set bclxif, downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 323 pic18f87k22 family figure 21-29: bus collision d uring start condition (sclx = 0 ) figure 21-30: brg reset due to sdax arbitr ation during start condition sdax sclx sen bus collision occurs, set bclxif sclx = 0 before sdax = 0 , set sen, enable start sequence if sdax = 1 , sclx = 1 t brg t brg sdax = 0 , sclx = 1 bclxif s sspxif interrupt cleared in software bus collision occurs, set bclxif sclx = 0 before brg time-out, 0 0 0 0 sdax sclx sen set s less than t brg t brg sdax = 0 , sclx = 1 bclxif s sspxif s interrupts cleared in software set sspxif sdax = 0 , sclx = 1 , sclx pulled low after brg time-out set sspxif 0 sdax pulled low by other master, reset brg and assert sdax set sen, enable start sequence if sdax = 1 , sclx = 1 downloaded from: http:///
pic18f87k22 family ds39960d-page 324 ? 2009-2011 microchip technology inc. 21.4.17.2 bus collision during a repeated start condition during a repeated start condition, a bus collision occurs if: a) a low level is sampled on sdax when sclx goes from a low level to a high level. b) sclx goes low before sdax is asserted low, indicating that another master is attempting to transmit a data 1 . when the user deasserts sdax and the pin is allowed to float high, the brg is loaded with sspxadd<6:0> and counts down to 0. the sclx pin is then deasserted and when sampled high, the sdax pin is sampled. if sdax is low, a bus collision has occurred (i.e., another master is attempting to transmit a data 0 , figure 21-31 ). if sdax is sampled high, the brg is reloaded and begins counting. if sdax goes from high-to-low before the brg times out, no bus collision occurs because no two masters can assert sdax at exactly the same time. if sclx goes from high-to-low before the brg times out and sdax has not already been asserted, a bus collision occurs. in this case, another master is attempting to transmit a data 1 during the repeated start condition (see figure 21-32 ). if, at the end of the brg time-out, both sclx and sdax are still high, the sdax pin is driven low and the brg is reloaded and begins counting. at the end of the count, regardless of the status of the sclx pin, the sclx pin is driven low and the repeated start condition is complete. figure 21-31: bus collision during a repeat ed start condition (case 1) figure 21-32: bus collision during repeated start condition (case 2) sdax sclx rsen bclxif s sspxif sample sdax when sclx goes high, if sdax = 0 , set bclxif and release sdax and sclx cleared in software 0 0 sdax sclx bclxif rsen s sspxif interrupt cleared in software sclx goes low before sdax, set bclxif, release sdax and sclx t brg t brg 0 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 325 pic18f87k22 family 21.4.17.3 bus collision during a stop condition bus collision occurs during a stop condition if: a) after the sdax pin has been deasserted and allowed to float high, sdax is sampled low after the brg has timed out. b) after the sclx pin is deasserted, sclx is sampled low before sdax goes high. the stop condition begins with sdax asserted low. when sdax is sampled low, the sclx pin is allowed to float. when the pin is sampled high (clock arbitration), the baud rate generator is loaded with sspxadd<6:0> and counts down to 0. after the brg times out, sdax is sampled. if sdax is sampled low, a bus collision has occurred. this is due to another master attempting to drive a data 0 ( figure 21-33 ). if the sclx pin is sampled low before sdax is allowed to float high, a bus collision occurs. this is another case of another master attempting to drive a data 0 ( figure 21-34 ). figure 21-33: bus collision during a stop condition (case 1) figure 21-34: bus collision during a stop condition (case 2) sdax sclx bclxif pen p sspxif t brg t brg t brg sdax asserted low sdax sampled low after t brg , set bclxif 0 0 sdax sclx bclxif pen p sspxif t brg t brg t brg assert sdax sclx goes low before sdax goes high, set bclxif 0 0 downloaded from: http:///
pic18f87k22 family ds39960d-page 326 ? 2009-2011 microchip technology inc. table 21-4: registers associated with i 2 c? operation name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir1 pspif adif rc1if tx1if ssp1if tmr1gif tmr2if tmr1if pie1 pspie adie rc1ie tx1ie ssp1ie tmr1gie tmr2ie tmr1ie ipr1 pspip adip rc1ip tx1ip ssp1ip tmr1gip tmr2ip tmr1ip pir2 oscfif ssp2if blc2if bcl1if hlvdif tmr3if tmr3gif pie2 oscfie ssp2ie blc2ie bcl1ie hlvdie tmr3ie tmr3gie ipr2 oscfip ssp2ip blc2ip bcl1ip hlvdip tmr3ip tmr3gip pir3 tmr5gif rc2if tx2if ctmuif ccp2if ccp1if rtccif pie3 tmr5gie rc2ie tx2ie ctmuie ccp2ie ccp1ie rtccie ipr3 tmr5gip rc2ip tx2ip ctmuip ccp2ip ccp1ip rtccip trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 trisd trisd7 trisd6 trisd5 trisd4 trisd3 trisd2 trisd1 trisd0 ssp1buf mssp1 receive buffer/transmit register ssp1add mssp1 address register (i 2 c slave mode), mssp1 baud rate reload register (i 2 c master mode) ssp1msk ( 1 ) msk7 msk6 msk5 msk4 msk3 msk2 msk1 msk0 ssp1con1 wcol sspov sspen ckp sspm3 sspm2 sspm1 sspm0 ssp1con2 gcen ackstat ackdt acken rcen pen rsen sen gcen ackstat admsk5 ( 2 ) admsk4 ( 2 ) admsk3 ( 2 ) admsk2 ( 2 ) admsk1 ( 2 ) sen ssp1stat smp cke d/a psr / w ua bf ssp2buf mssp2 receive buffer/transmit register ssp2add mssp2 address register (i 2 c slave mode), mssp2 baud rate reload register (i 2 c master mode) ssp2msk ( 1 ) msk7 msk6 msk5 msk4 msk3 msk2 msk1 msk0 ssp2con1 wcol sspov sspen ckp sspm3 sspm2 sspm1 sspm0 ssp2con2 gcen ackstat ackdt acken rcen pen rsen sen gcen ackstat admsk5 ( 2 ) admsk4 ( 2 ) admsk3 ( 2 ) admsk2 ( 2 ) admsk1 ( 2 ) sen ssp2stat smp cke d/a psr / w ua bf pmd0 ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd legend: = unimplemented, read as 0 . shaded cells are not used by the mssp module in i 2 c? mode. note 1: sspxmsk shares the same address in sfr space as sspxadd, but is only accessible in certain i 2 c slave operating modes in 7-bit masking mode. see section 21.4.3.4 7-bit address masking mode for more details. 2: alternate bit definitions for use in i 2 c slave mode operations only. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 327 pic18f87k22 family 22.0 enhanced universal synchronous asynchronous receiver transmitter (eusart) the enhanced universal synchronous asynchronous receiver transmitter (eusart) module is one of two serial i/o modules. (generically, the eusart is also known as a serial communications interface or sci.) the eusart can be configured as a full-duplex, asynchronous system that can communicate with peripheral devices, such as crt terminals and personal computers. it can also be configured as a half-duplex synchronous system that can communicate with peripheral devices, such as a/d or d/a integrated circuits, serial eeproms, etc. the enhanced usart module implements additional features, including automatic baud rate detection and calibration, automatic wake-up on sync break recep- tion and 12-bit break character transmit. these make it ideally suited for use in local interconnect network bus (lin/j2602 bus) systems. all members of the pic18f87k22 family are equipped with two independent eusart modules, referred to as eusart1 and eusart2. they can be configured in the following modes: asynchronous (full duplex) with: - auto-wake-up on character reception - auto-baud calibration - 12-bit break character transmission synchronous C master (half duplex) with selectable clock polarity synchronous C slave (half duplex) with selectable clock polarity the pins of eusart1 and eusart2 are multiplexed with the functions of portc (rc6/tx1/ck1 and rc7/rx1/dt1) and portg (rg1/tx2/ck2/an19/c3out and rg2/rx2/dt2/an18/c3ina), respectively. in order to configure these pins as an eusart: for eusart1: - bit, spen (rcsta1<7>), must be set (= 1 ) - bit, trisc<7>, must be set (= 1 ) - bit, trisc<6>, must be cleared (= 0 ) for asynchronous and synchronous master modes - bit, trisc<6>, must be set (= 1 ) for synchronous slave mode for eusart2: - bit, spen (rcsta2<7>), must be set (= 1 ) - bit, trisg<2>, must be set (= 1 ) - bit trisg<1> must be cleared (= 0 ) for asynchronous and synchronous master modes - bit, trisc<6>, must be set (= 1 ) for synchronous slave mode the operation of each enhanced usart module is controlled through three registers: transmit status and control (txstax) receive status and control (rcstax) baud rate control (baudconx) these are detailed on the following pages in register 22-1 , register 22-2 and register 22-3 , respectively. note: the eusart control will automatically reconfigure the pin from input to output as needed. note: throughout this section, references to register and bit names that may be asso- ciated with a specific eusart module are referred to generically by the use of x in place of the specific module number. thus, rcstax might refer to the receive status register for either eusart1 or eusart2. downloaded from: http:///
pic18f87k22 family ds39960d-page 328 ? 2009-2011 microchip technology inc. register 22-1: txstax: transmit status and control register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r-1 r/w-0 csrc tx9 txen ( 1 ) sync sendb brgh trmt tx9d bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 csrc: clock source select bit asynchronous mode: dont care. synchronous mode: 1 = master mode (clock generated internally from brg) 0 = slave mode (clock from external source) bit 6 tx9: 9-bit transmit enable bit 1 = selects 9-bit transmission 0 = selects 8-bit transmission bit 5 txen: transmit enable bit ( 1 ) 1 = transmit is enabled 0 = transmit is disabled bit 4 sync: eusart mode select bit 1 = synchronous mode 0 = asynchronous mode bit 3 sendb: send break character bit asynchronous mode: 1 = send sync break on next transmission (cleared by hardware upon completion) 0 = sync break transmission has completed synchronous mode: dont care. bit 2 brgh: high baud rate select bit asynchronous mode: 1 = high speed 0 = low speed synchronous mode: unused in this mode. bit 1 trmt: transmit shift register status bit 1 = tsr is empty 0 = tsr is full bit 0 tx9d: 9th bit of transmit data can be address/data bit or a parity bit. note 1: sren/cren overrides txen in sync mode. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 329 pic18f87k22 family register 22-2: rcstax: receive stat us and control register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r-0 r-0 r-x spen rx9 sren cren adden ferr oerr rx9d bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 spen: serial port enable bit 1 = serial port is enabled 0 = serial port is disabled (held in reset) bit 6 rx9: 9-bit receive enable bit 1 = selects 9-bit reception 0 = selects 8-bit reception bit 5 sren: single receive enable bit asynchronous mode : dont care. synchronous mode C master: 1 = enables single receive 0 = disables single receive this bit is cleared after reception is complete. synchronous mode C slave: dont care. bit 4 cren: continuous receive enable bit asynchronous mode: 1 = enables receiver 0 = disables receiver synchronous mode: 1 = enables continuous receive until enable bit, cren, is cleared (cren overrides sren) 0 = disables continuous receive bit 3 adden: address detect enable bit asynchronous mode 9-bit (rx9 = 1 ): 1 = enables address detection, enables interrupt and loads the receive buffer when rsr<8> is set 0 = disables address detection, all bytes are received and the ninth bit can be used as a parity bit asynchronous mode 8- bit (rx9 = 0 ): dont care. bit 2 ferr: framing error bit 1 = framing error (can be cleared by reading the rcregx register and receiving the ne xt valid byte) 0 = no framing error bit 1 oerr: overrun error bit 1 = overrun error (can be cleared by clearing bit, cren) 0 = no overrun error bit 0 rx9d: 9th bit of received data this can be an address/data bit or a parity bit and must be calculated by user firmware. downloaded from: http:///
pic18f87k22 family ds39960d-page 330 ? 2009-2011 microchip technology inc. register 22-3: baudconx: baud rate control register r/w-0 r-1 r/w-0 r/w-0 r/w-0 u-0 r/w-0 r/w-0 abdovf rcidl rxdtp txckp brg16 wue abden bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 abdovf: auto-baud acquisition rollover status bit 1 = a brg rollover has occurred during auto-baud rate detect mode (must be cleared in software) 0 = no brg rollover has occurred bit 6 rcidl: receive operation idle status bit 1 = receive operation is idle 0 = receive operation is active bit 5 rxdtp: data/receive polarity select bit asynchronous mode: 1 = receive data (rxx) is inverted (active-low) 0 = receive data (rxx) is not inverted (active-high) synchronous mode: 1 = data (dtx) is inverted (active-low) 0 = data (dtx) is not inverted (active-high) bit 4 txckp: synchronous clock polarity select bit asynchronous mode: 1 = idle state for transmit (txx) is a low level 0 = idle state for transmit (txx) is a high level synchronous mode: 1 = idle state for clock (ckx) is a high level 0 = idle state for clock (ckx) is a low level bit 3 brg16: 16-bit baud rate register enable bit 1 = 16-bit baud rate generator C spbrghx and spbrgx 0 = 8-bit baud rate generator C spbrgx only (compatible mode), spbrghx value ignored bit 2 unimplemented: read as 0 bit 1 wue: wake-up enable bit asynchronous mode: 1 = eusart will continue to sample the rxx pin C interrupt generated on falling edge; bit cleared in hardware on following rising edge 0 = rxx pin not monitored or rising edge detected synchronous mode: unused in this mode. bit 0 abden: auto-baud detect enable bit asynchronous mode: 1 = enable baud rate measurement on the next character. requires reception of a sync field (55h); cleared in hardware upon completion. 0 = baud rate measurement is disabled or has completed synchronous mode: unused in this mode. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 331 pic18f87k22 family 22.1 baud rate generator (brg) the brg is a dedicated, 8-bit or 16-bit generator that supports both the asynchronous and synchronous modes of the eusart. by default, the brg operates in 8-bit mode; setting the brg16 bit (baudconx<3>) selects 16-bit mode. the spbrghx:spbrgx register pair controls the period of a free-running timer. in asynchronous mode, bits, brgh (txstax<2>) and brg16 (baudconx<3>), also control the baud rate. in synchronous mode, brgh is ignored. table 22-1 shows the formula for computation of the baud rate for different eusart modes which only apply in master mode (internally generated clock). given the desired baud rate and f osc , the nearest integer value for the spbrghx:spbrgx registers can be calculated using the formulas in tab le 2 2- 1 . from this, the error in baud rate can be determined. an example calculation is shown in example 22-1 . typical baud rates and error values for the various asynchronous modes are shown in ta b l e 2 2 - 2 . it may be advantageous to use the high baud rate (brgh = 1 ) or the 16-bit brg to reduce the baud rate error, or achieve a slow baud rate for a fast oscillator frequency. writing a new value to the spbrghx:spbrgx registers causes the brg timer to be reset (or cleared). this ensures the brg does not wait for a timer over- flow before outputting the new baud rate. when operated in the synchronous mode, spbrgh:spbrg values of 0000h and 0001h are not supported. in the asynchronous mode, all brg values may be used. 22.1.1 operation in power-managed modes the device clock is used to generate the desired baud rate. when one of the power-managed modes is entered, the new clock source may be operating at a different frequency. this may require an adjustment to the value in the spbrgx register pair. 22.1.2 sampling the data on the rxx pin (either rc7/rx1/dt1 or rg2/rx2/dt2/an18/c3ina) is sampled three times by a majority detect circuit to determine if a high or a low level is present at the rxx pin. table 22-1: baud rate formulas configuration bits brg/eusart mode baud rate formula sync brg16 brgh 000 8-bit/asynchronous f osc /[64 (n + 1)] 001 8-bit/asynchronous f osc /[16 (n + 1)] 010 16-bit/asynchronous 011 16-bit/asynchronous f osc /[4 (n + 1)] 10x 8-bit/synchronous 11x 16-bit/synchronous legend: x = dont care, n = value of spbrghx:spbrgx register pair downloaded from: http:///
pic18f87k22 family ds39960d-page 332 ? 2009-2011 microchip technology inc. example 22-1: calculat ing baud rate error table 22-2: registers associated with baud rate generator name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 txsta1 csrc tx9 txen sync sendb brgh trmt tx9d rcsta1 spen rx9 sren cren adden ferr oerr rx9d baudcon1 abdovf rcidl rxdtp txckp brg16 wue abden spbrgh1 eusart1 baud rate generator register high byte spbrg1 eusart1 baud rate generator register txsta2 csrc tx9 txen sync sendb brgh trmt tx9d rcsta2 spen rx9 sren cren adden ferr oerr rx9d baudcon2 abdovf rcidl rxdtp txckp brg16 wue abden spbrgh2 eusart2 baud rate generator register high byte spbrg2 eusart2 baud rate generator register pmd0 ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd legend: = unimplemented, read as 0 . shaded cells are not used by the brg. for a device with f osc of 16 mhz, desired baud rate of 9600, asynchronous mode, and 8-bit brg: desired baud rate = f osc /(64 ([spbrghx:spbrgx] + 1)) solving for spbrghx:spbrgx: x = ((f osc /desired baud rate)/64) C 1 = ((16000000/9600)/64) C 1 = [25.042] = 25 calculated baud rate = 16000000/(64 (25 + 1)) = 9615 error = (calculated baud rate C de sired baud rate)/desired baud rate = (9615 C 9600)/9600 = 0.16% downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 333 pic18f87k22 family table 22-3: baud rates for asynchronous modes baud rate (k) sync = 0 , brgh = 0 , brg16 = 0 f osc = 40.000 mhz f osc = 20.000 mhz f osc = 10.000 mhz f osc = 8.000 mhz actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) 0 . 3 1.2 1.221 1.73 255 1.202 0.16 129 1.201 -0.16 103 2.4 2.441 1.73 255 2.404 0.16 129 2.404 0.16 64 2.403 -0.16 51 9.6 9.615 0.16 64 9.766 1.73 31 9.766 1.73 15 9.615 -0.16 12 19.2 19.531 1.73 31 19.531 1.73 15 19.531 1.73 7 57.6 56.818 -1.36 10 62.500 8.51 4 52.083 -9.58 2 115.2 125.000 8.51 4 104.167 -9.58 2 78.125 -32.18 1 baud rate (k) sync = 0 , brgh = 0 , brg16 = 0 f osc = 4.000 mhz f osc = 2.000 mhz f osc = 1.000 mhz actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) 0.3 0.300 0.16 207 0.300 -0.16 103 0.300 -0.16 51 1.2 1.202 0.16 51 1.201 -0.16 25 1.201 -0.16 12 2.4 2.404 0.16 25 2.403 -0.16 12 9.6 8.929 -6.99 6 19.2 20.833 8.51 2 57.6 62.500 8.51 0 115.2 62.500 -45.75 0 baud rate (k) sync = 0 , brgh = 1 , brg16 = 0 f osc = 40.000 mhz f osc = 20.000 mhz f osc = 10.000 mhz f osc = 8.000 mhz actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) 0 . 3 1 . 2 2.4 2.441 1.73 255 2.403 -0.16 207 9.6 9.766 1.73 255 9.615 0.16 129 9.615 0.16 64 9.615 -0.16 51 19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19.230 -0.16 25 57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55.555 3.55 8 115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4 baud rate (k) sync = 0 , brgh = 1 , brg16 = 0 f osc = 4.000 mhz f osc = 2.000 mhz f osc = 1.000 mhz actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) 0.3 0.300 -0.16 207 1.2 1.202 0.16 207 1.201 -0.16 103 1.201 -0.16 51 2.4 2.404 0.16 103 2.403 -0.16 51 2.403 -0.16 25 9.6 9.615 0.16 25 9.615 -0.16 12 19.2 19.231 0.16 12 57.6 62.500 8.51 3 115.2 125.000 8.51 1 downloaded from: http:///
pic18f87k22 family ds39960d-page 334 ? 2009-2011 microchip technology inc. baud rate (k) sync = 0 , brgh = 0 , brg16 = 1 f osc = 40.000 mhz f osc = 20.000 mhz f osc = 10.000 mhz f osc = 8.000 mhz actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) 0.3 0.300 0.00 8332 0.300 0.02 4165 0.300 0.02 2082 0.300 -0.04 1665 1.2 1.200 0.02 2082 1.200 -0.03 1041 1.200 -0.03 520 1.201 -0.16 415 2.4 2.402 0.06 1040 2.399 -0.03 520 2.404 0.16 259 2.403 -0.16 207 9.6 9.615 0.16 259 9.615 0.16 129 9.615 0.16 64 9.615 -0.16 51 19.2 19.231 0.16 129 19.231 0.16 64 19.531 1.73 31 19.230 -0.16 25 57.6 58.140 0.94 42 56.818 -1.36 21 56.818 -1.36 10 55.555 3.55 8 115.2 113.636 -1.36 21 113.636 -1.36 10 125.000 8.51 4 baud rate (k) sync = 0 , brgh = 0 , brg16 = 1 f osc = 4.000 mhz f osc = 2.000 mhz f osc = 1.000 mhz actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) 0.3 0.300 0.04 832 0.300 -0.16 415 0.300 -0.16 207 1.2 1.202 0.16 207 1.201 -0.16 103 1.201 -0.16 51 2.4 2.404 0.16 103 2.403 -0.16 51 2.403 -0.16 25 9.6 9.615 0.16 25 9.615 -0.16 12 19.2 19.231 0.16 12 57.6 62.500 8.51 3 115.2 125.000 8.51 1 baud rate (k) sync = 0 , brgh = 1 , brg16 = 1 or sync = 1 , brg16 = 1 f osc = 40.000 mhz f osc = 20.000 mhz f osc = 10.000 mhz f osc = 8.000 mhz actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) 0.3 0.300 0.00 33332 0.300 0.00 16665 0.300 0.00 8332 0.300 -0.01 6665 1.2 1.200 0.00 8332 1.200 0.02 4165 1.200 0.02 2082 1.200 -0.04 1665 2.4 2.400 0.02 4165 2.400 0.02 2082 2.402 0.06 1040 2.400 -0.04 832 9.6 9.606 0.06 1040 9.596 -0.03 520 9.615 0.16 259 9.615 -0.16 207 19.2 19.193 -0.03 520 19.231 0.16 259 19.231 0.16 129 19.230 -0.16 103 57.6 57.803 0.35 172 57.471 -0.22 86 58.140 0.94 42 57.142 0.79 34 115.2 114.943 -0.22 86 116.279 0.94 42 113.636 -1.36 21 117.647 -2.12 16 baud rate (k) sync = 0 , brgh = 1 , brg16 = 1 or sync = 1 , brg16 = 1 f osc = 4.000 mhz f osc = 2.000 mhz f osc = 1.000 mhz actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) actual rate (k) % error spbrg value (decimal) 0.3 0.300 0.01 3332 0.300 -0.04 1665 0.300 -0.04 832 1.2 1.200 0.04 832 1.201 -0.16 415 1.201 -0.16 207 2.4 2.404 0.16 415 2.403 -0.16 207 2.403 -0.16 103 9.6 9.615 0.16 103 9.615 -0.16 51 9.615 -0.16 25 19.2 19.231 0.16 51 19.230 -0.16 25 19.230 -0.16 12 57.6 58.824 2.12 16 55.555 3.55 8 115.2 111.111 -3.55 8 table 22-3: baud rates for asynchronous modes (continued) downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 335 pic18f87k22 family 22.1.3 auto-baud rate detect the enhanced usart module supports the automatic detection and calibration of baud rate. this feature is active only in asynchronous mode and while the wue bit is clear. the automatic baud rate measurement sequence ( figure 22-1 ) begins whenever a start bit is received and the abden bit is set. the calculation is self-averaging. in the auto-baud rate detect (abd) mode, the clock to the brg is reversed. rather than the brg clocking the incoming rxx signal, the rxx signal is timing the brg. in abd mode, the internal baud rate generator is used as a counter to time the bit period of the incoming serial byte stream. once the abden bit is set, the state machine will clear the brg and look for a start bit. the auto-baud rate detect must receive a byte with the value, 55h (ascii u, which is also the lin/j2602 bus sync character), in order to calculate the proper bit rate. the measurement is taken over both a low and a high bit time in order to minimize any effects caused by asymmetry of the incom- ing signal. after a start bit, the spbrgx begins counting up, using the preselected clock source on the first rising edge of rxx. after eight bits on the rxx pin or the fifth rising edge, an accumulated value totalling the proper brg period is left in the spbrghx:spbrgx register pair. once the 5th edge is seen (this should correspond to the stop bit), the abden bit is automatically cleared. if a rollover of the brg occurs (an overflow from ffffh to 0000h), the event is trapped by the abdovf status bit (baudconx<7>). it is set in hardware by brg roll- overs and can be set or cleared by the user in software. abd mode remains active after rollover events and the abden bit remains set ( figure 22-2 ). while calibrating the baud rate period, the brg regis- ters are clocked at 1/8th the preconfigured clock rate. the brg clock will be configured by the brg16 and brgh bits. the brg16 bit must be set to use both spbrg1 and spbrgh1 as a 16-bit counter. this allows the user to verify that no carry occurred for 8-bit modes by checking for 00h in the spbrghx register. refer to table 22-4 for counter clock rates to the brg. while the abd sequence takes place, the eusart state machine is held in idle. the rcxif interrupt is set once the fifth rising edge on rxx is detected. the value in the rcregx needs to be read to clear the rcxif interrupt. the contents of rcregx should be discarded. table 22-4: brg counter clock rates 22.1.3.1 abd and eusart transmission since the brg clock is reversed during abd acquisi- tion, the eusart transmitter cannot be used during abd. this means that whenever the abden bit is set, txregx cannot be written to. users should also ensure that abden does not become set during a transmit sequence. failing to do this may result in unpredictable eusart operation. note 1: if the wue bit is set with the abden bit, auto-baud rate detection will occur on the byte following the break character. 2: it is up to the user to determine that the incoming character baud rate is within the range of the selected brg clock source. some combinations of oscillator fre- quency and eusart baud rates are not possible due to bit error rates. overall system timing and communication baud rates must be taken into consideration when using the auto-baud rate detection feature. 3: to maximize baud rate range, if that feature is used, it is recommended that the brg16 bit (baudconx<3>) be set. brg16 brgh brg counter clock 00 f osc /512 01 f osc /128 10 f osc /128 11 f osc /32 downloaded from: http:///
pic18f87k22 family ds39960d-page 336 ? 2009-2011 microchip technology inc. figure 22-1: automatic baud rate calculation figure 22-2: brg overflow sequence brg value rxx pin abden bit rcxif bit bit 0 bit 1 (interrupt) read rcregx brg clock start auto-cleared set by user xxxxh 0000h edge #1 bit 2 bit 3 edge #2 bit 4 bit 5 edge #3 bit 6 bit 7 edge #4 001ch note: the abd sequence requires the eusart module to be configured in asynchronous mode and wue = 0 . spbrgx xxxxh 1ch spbrghx xxxxh 00h edge #5 stop bit start bit 0 xxxxh 0000h 0000h ffffh brg clock abden bit rxx pin abdovf bit brg value downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 337 pic18f87k22 family 22.2 eusart asynchronous mode the asynchronous mode of operation is selected by clearing the sync bit (txstax<4>). in this mode, the eusart uses standard non-return-to-zero (nrz) format (one start bit, eight or nine data bits and one stop bit). the most common data format is 8 bits. an on-chip, dedicated 8-bit/16-bit baud rate generator can be used to derive standard baud rate frequencies from the oscillator. the eusart transmits and receives the lsb first. the eusarts transmitter and receiver are functionally independent but use the same data format and baud rate. the baud rate generator produces a clock, either x16 or x64 of the bit shift rate, depending on the brgh and brg16 bits (txstax<2> and baudconx<3>). parity is not supported by the hardware but can be implemented in software and stored as the 9th data bit. when operating in asynchronous mode, the eusart module consists of the following important elements: baud rate generator sampling circuit asynchronous transmitter asynchronous receiver auto-wake-up on sync break character 12-bit break character transmit auto-baud rate detection 22.2.1 eusart asynchronous transmitter the eusart transmitter block diagram is shown in figure 22-3 . the heart of the transmitter is the transmit (serial) shift register (tsr). the shift register obtains its data from the read/write transmit buffer register, txregx. the txregx register is loaded with data in software. the tsr register is not loaded until the stop bit has been transmitted from the previous load. as soon as the stop bit is transmitted, the tsr is loaded with new data from the txregx register (if available). once the txregx register transfers the data to the tsr register (occurs in one t cy ), the txregx register is empty and the txxif flag bit is set. this interrupt can be enabled or disabled by setting or clearing the inter- rupt enable bit, txxie. txxif will be set regardless of the state of txxie; it cannot be cleared in software. txxif is also not cleared immediately upon loading txregx, but becomes valid in the second instruction cycle following the load instruction. polling txxif immediately following a load of txregx will return invalid results. while txxif indicates the status of the txregx regis- ter; another bit, trmt (txstax<1>), shows the status of the tsr register. trmt is a read-only bit which is set when the tsr register is empty. no interrupt logic is tied to this bit so the user has to poll this bit in order to determine if the tsr register is empty. to set up an asynchronous transmission: 1. initialize the spbrghx:spbrgx registers for the appropriate baud rate. set or clear the brgh and brg16 bits, as required, to achieve the desired baud rate. 2. enable the asynchronous serial port by clearing bit, sync, and setting bit, spen. 3. if interrupts are desired, set enable bit, txxie. 4. if 9-bit transmission is desired, set transmit bit, tx9; can be used as an address/data bit. 5. enable the transmission by setting bit, txen, which will also set bit, txxif. 6. if 9-bit transmission is selected, the ninth bit should be loaded in bit, tx9d. 7. load data to the txregx register (starts transmission). 8. if using interrupts, ensure that the gie and peie bits in the intcon register (intcon<7:6>) are set. note 1: the tsr register is not mapped in data memory, so it is not available to the user. 2: flag bit, txxif, is set when enable bit, txen, is set. downloaded from: http:///
pic18f87k22 family ds39960d-page 338 ? 2009-2011 microchip technology inc. figure 22-3: eusart transmit block diagram figure 22-4: asynchronous transmission figure 22-5: asynchronous transmiss ion (back-to-back) txxif txxie interrupt txen baud rate clk spbrgx baud rate generator tx9d msb lsb data bus txregx register tsr register (8) 0 tx9 trmt spen txx pin pin buffer and control 8 ????????? spbrghx brg16 word 1 word 1 transmit shift reg start bit bit 0 bit 1 bit 7/8 write to txregx brg output (shift clock) txx (pin) txxif bit (transmit buffer reg. empty flag) trmt bit (transmit shift reg. empty flag) 1 t cy stop bit word 1 transmit shift reg. write to txregx brg output (shift clock) txx (pin) txxif bit (interrupt reg. flag) trmt bit (transmit shift reg. empty flag) word 1 word 2 word 1 word 2 stop bit start bit transmit shift reg. word 1 word 2 bit 0 bit 1 bit 7/8 bit 0 note: this timing diagram shows two consecutive transmissions. 1 t cy 1 t cy start bit downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 339 pic18f87k22 family table 22-5: registers associated wi th asynchronous transmission name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir1 pspif adif rc1if tx1if ssp1if tmr1gif tmr2if tmr1if pie1 pspie adie rc1ie tx1ie ssp1ie tmr1gie tmr2ie tmr1ie ipr1 pspip adip rc1ip tx1ip ssp1ip tmr1gip tmr2ip tmr1ip pir3 tmr5gif rc2if tx2if ctmuif ccp2if ccp1if rtccif pie3 tmr5gie rc2ie tx2ie ctmuie ccp2ie ccp1ie rtccie ipr3 tmr5gip rc2ip tx2ip ctmuip ccp2ip ccp1ip rtccip rcsta1 spen rx9 sren cren adden ferr oerr rx9d txreg1 eusart1 transmit register txsta1 csrc tx9 txen sync sendb brgh trmt tx9d baudcon1 abdovf rcidl rxdtp txckp brg16 wue abden spbrgh1 eusart1 baud rate generator register high byte spbrg1 eusart1 baud rate generator register rcsta2 spen rx9 sren cren adden ferr oerr rx9d txreg2 eusart2 transmit register txsta2 csrc tx9 txen sync sendb brgh trmt tx9d baudcon2 abdovf rcidl rxdtp txckp brg16 wue abden spbrgh2 eusart2 baud rate generator register high byte spbrg2 eusart2 baud rate generator register odcon3 u2od u1od ctmuds pmd0 ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd legend: = unimplemented locations read as 0 . shaded cells are not used for asynchronous transmission. downloaded from: http:///
pic18f87k22 family ds39960d-page 340 ? 2009-2011 microchip technology inc. 22.2.2 eusart asynchronous receiver the receiver block diagram is shown in figure 22-6 . the data is received on the rxx pin and drives the data recovery block. the data recovery block is actually a high-speed shifter operating at x16 times the baud rate, whereas the main receive serial shifter operates at the bit rate or at f osc . this mode would typically be used in rs-232 systems. to set up an asynchronous reception: 1. initialize the spbrghx:spbrgx registers for the appropriate baud rate. set or clear the brgh and brg16 bits, as required, to achieve the desired baud rate. 2. enable the asynchronous serial port by clearing bit, sync, and setting bit, spen. 3. if interrupts are desired, set enable bit, rcxie. 4. if 9-bit reception is desired, set bit, rx9. 5. enable the reception by setting bit, cren. 6. flag bit, rcxif, will be set when reception is complete and an interrupt will be generated if enable bit, rcxie, was set. 7. read the rcstax register to get the 9th bit (if enabled) and determine if any error occurred during reception. 8. read the 8-bit received data by reading the rcregx register. 9. if any error occurred, clear the error by clearing enable bit, cren. 10. if using interrupts, ensure that the gie and peie bits in the intcon register (intcon<7:6>) are set. 22.2.3 setting up 9-bit mode with address detect this mode would typically be used in rs-485 systems. to set up an asynchronous reception with address detect enable: 1. initialize the spbrghx:spbrgx registers for the appropriate baud rate. set or clear the brgh and brg16 bits, as required, to achieve the desired baud rate. 2. enable the asynchronous serial port by clearing the sync bit and setting the spen bit. 3. if interrupts are required, set the rcen bit and select the desired priority level with the rcxip bit. 4. set the rx9 bit to enable 9-bit reception. 5. set the adden bit to enable address detect. 6. enable reception by setting the cren bit. 7. the rcxif bit will be set when reception is complete. the interrupt will be acknowledged if the rcxie and gie bits are set. 8. read the rcstax register to determine if any error occurred during reception, as well as read bit 9 of data (if applicable). 9. read rcregx to determine if the device is being addressed. 10. if any error occurred, clear the cren bit. 11. if the device has been addressed, clear the adden bit to allow all received data into the receive buffer and interrupt the cpu. figure 22-6: eusart receiv e block diagram x64 baud rate clk baud rate generator rxx pin buffer and control spen data recovery cren oerr ferr rsr register msb lsb rx9d rcregx register fifo interrupt rcxif rcxie data bus 8 ? 64 ? 16 or stop start (8) 7 1 0 rx9 ??????? spbrgx spbrghx brg16 or ? 4 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 341 pic18f87k22 family figure 22-7: asynchronous reception table 22-6: registers associated with asynchronous reception name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir1 pspif adif rc1if tx1if ssp1if tmr1gif tmr2if tmr1if pie1 pspie adie rc1ie tx1ie ssp1ie tmr1gie tmr2ie tmr1ie ipr1 pspip adip rc1ip tx1ip ssp1ip tmr1gip tmr2ip tmr1ip pir3 tmr5gif rc2if tx2if ctmuif ccp2if ccp1if rtccif pie3 tmr5gie rc2ie tx2ie ctmuie ccp2ie ccp1ie rtccie ipr3 tmr5gip rc2ip tx2ip ctmuip ccp2ip ccp1ip rtccip rcsta1 spen rx9 sren cren adden ferr oerr rx9d rcreg1 eusart1 receive register txsta1 csrc tx9 txen sync sendb brgh trmt tx9d baudcon1 abdovf rcidl rxdtp txckp brg16 wue abden spbrgh1 eusart1 baud rate generator register high byte spbrg1 eusart1 baud rate generator register rcsta2 spen rx9 sren cren adden ferr oerr rx9d rcreg2 eusart2 receive register txsta2 csrc tx9 txen sync sendb brgh trmt tx9d baudcon2 abdovf rcidl rxdtp txckp brg16 wue abden spbrgh2 eusart2 baud rate generator register high byte spbrg2 eusart2 baud rate generator register odcon3 u2od u1od ctmuds pmd0 ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd legend: = unimplemented locations read as 0 . shaded cells are not used for asynchronous reception. start bit bit 7/8 bit 1 bit 0 bit 7/8 bit 0 stop bit start bit start bit bit 7/8 stop bit rxx (pin) rcv buffer reg rcv shift reg read rcv buffer reg rcregx rcxif (interrupt flag) oerr bit cren word 1 rcregx word 2 rcregx stop bit note: this timing diagram shows three words appearing on the rxx input. the rcregx (r eceive buffer) is read after the third word, causing the oerr (overrun) bit to be set. downloaded from: http:///
pic18f87k22 family ds39960d-page 342 ? 2009-2011 microchip technology inc. 22.2.4 auto-wake-up on sync break character during sleep mode, all clocks to the eusart are suspended. because of this, the baud rate generator is inactive and a proper byte reception cannot be per- formed. the auto-wake-up feature allows the controller to wake up due to activity on the rxx/dtx line while the eusart is operating in asynchronous mode. the auto-wake-up feature is enabled by setting the wue bit (baudconx<1>). once set, the typical receive sequence on rxx/dtx is disabled and the eusart remains in an idle state, monitoring for a wake-up event independent of the cpu mode. a wake-up event consists of a high-to-low transition on the rxx/dtx line. (this coincides with the start of a sync break or a wake-up signal character for the lin/j2602 protocol.) following a wake-up event, the module generates an rcxif interrupt. the interrupt is generated synchro- nously to the q clocks in normal operating modes ( figure 22-8 ) and asynchronously if the device is in sleep mode ( figure 22-9 ). the interrupt condition is cleared by reading the rcregx register. the wue bit is automatically cleared once a low-to-high transition is observed on the rxx line following the wake-up event. at this point, the eusart module is in idle mode and returns to normal operation. this signals to the user that the sync break event is over. 22.2.4.1 special considerations using auto-wake-up since auto-wake-up functions by sensing rising edge transitions on rxx/dtx, information with any state changes before the stop bit may signal a false end-of-character (eoc) and cause data or framing errors. to work properly, therefore, the initial character in the transmission must be all 0 s. this can be 00h (8 bits) for standard rs-232 devices or 000h (12 bits) for the lin/j2602 bus. oscillator start-up time must also be considered, especially in applications using oscillators with longer start-up intervals (i.e., hs or hspll mode). the sync break (or wake-up signal) character must be of sufficient length and be followed by a sufficient interval to allow enough time for the selected oscillator to start and provide proper initialization of the eusart. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 343 pic18f87k22 family 22.2.4.2 special considerations using the wue bit the timing of wue and rcxif events may cause some confusion when it comes to determining the validity of received data. as noted, setting the wue bit places the eusart in an idle mode. the wake-up event causes a receive interrupt by setting the rcxif bit. the wue bit is cleared after this when a rising edge is seen on rxx/dtx. the interrupt condition is then cleared by reading the rcregx register. ordinarily, the data in rcregx will be dummy data and should be discarded. the fact that the wue bit has been cleared (or is still set), and the rcxif flag is set, should not be used as an indicator of the integrity of the data in rcregx. users should consider implementing a parallel method in firmware to verify received data integrity. to assure that no actual data is lost, check the rcidl bit to verify that a receive operation is not in process. if a receive operation is not occurring, the wue bit may then be set just prior to entering sleep mode. figure 22-8: auto-wake-up bit (wue) timings during no rmal operation figure 22-9: auto-wake-up bit (wue) timings during sleep q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 osc1 wue bit (1) rxx/dtx line rcxif note 1: the eusart remains in idle while the wue bit is set. bit set by user cleared due to user read of rcregx auto-cleared q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 osc1 wue bit (2) rxx/dtx line rcxif cleared due to user read of rcregx sleep command executed note 1: if the wake-up event requires long oscillator warm-up time, the auto-clear of the wue bit can occur before the oscillator is re ady. this sequence should not depend on the presence of q clocks. 2: the eusart remains in idle while the wue bit is set. sleep ends note 1 auto-cleared bit set by user downloaded from: http:///
pic18f87k22 family ds39960d-page 344 ? 2009-2011 microchip technology inc. 22.2.5 break character sequence the eusart module has the capability of sending the special break character sequences that are required by the lin/j2602 bus standard. the break character transmit consists of a start bit, followed by twelve 0 bits and a stop bit. the frame break character is sent whenever the sendb and txen bits (txstax<3> and txstax<5>, respectively) are set while the transmit shift register is loaded with data. note that the value of data written to txregx will be ignored and all 0 s will be transmitted. the sendb bit is automatically reset by hardware after the corresponding stop bit is sent. this allows the user to preload the transmit fifo with the next transmit byte following the break character (typically, the sync character in the lin/j2602 specification). note that the data value written to the txregx for the break character is ignored. the write simply serves the purpose of initiating the proper sequence. the trmt bit indicates when the transmit operation is active or idle, just as it does during normal transmis- sion. see figure 22-10 for the timing of the break character sequence. 22.2.5.1 break and sync transmit sequence the following sequence will send a message frame header made up of a break, followed by an auto-baud sync byte. this sequence is typical of a lin/j2602 bus master. 1. configure the eusart for the desired mode. 2. set the txen and sendb bits to set up the break character. 3. load the txregx with a dummy character to initiate transmission (the value is ignored). 4. write 55h to txregx to load the sync character into the transmit fifo buffer. 5. after the break has been sent, the sendb bit is reset by hardware. the sync character now transmits in the preconfigured mode. when the txregx becomes empty, as indicated by the txxif, the next data byte can be written to txregx. 22.2.6 receiving a break character the enhanced usart module can receive a break character in two ways. the first method forces configuration of the baud rate at a frequency of 9/13 the typical speed. this allows for the stop bit transition to be at the correct sampling location (13 bits for break versus start bit and 8 data bits for typical data). the second method uses the auto-wake-up feature described in section 22.2.4 auto-wake-up on sync break character . by enabling this feature, the eusart will sample the next two transitions on rxx/dtx, cause an rcxif interrupt and receive the next data byte followed by another interrupt. note that following a break character, the user will typically want to enable the auto-baud rate detect feature. for both methods, the user can set the abden bit once the txxif interrupt is observed. figure 22-10: send break character sequence write to txregx brg output (shift clock) start bit bit 0 bit 1 bit 11 stop bit break txxif bit (transmit buffer reg. empty flag) txx (pin) trmt bit (transmit shift reg. empty flag) sendb bit (transmit shift reg. empty flag) sendb sampled here auto-cleared dummy write downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 345 pic18f87k22 family 22.3 eusart synchronous master mode the synchronous master mode is entered by setting the csrc bit (txstax<7>). in this mode, the data is transmitted in a half-duplex manner (i.e., transmission and reception do not occur at the same time). when transmitting data, the reception is inhibited and vice versa. synchronous mode is entered by setting bit, sync (txstax<4>). in addition, enable bit, spen (rcstax<7>), is set in order to configure the txx and rxx pins to ckx (clock) and dtx (data) lines, respectively. the master mode indicates that the processor trans- mits the master clock on the ckx line. clock polarity is selected with the txckp bit (baudconx<4>). setting txckp sets the idle state on ckx as high, while clear- ing the bit sets the idle state as low. this option is provided to support microwire devices with this module. 22.3.1 eusart synchronous master transmission the eusart transmitter block diagram is shown in figure 22-3 . the heart of the transmitter is the transmit (serial) shift register (tsr). the shift register obtains its data from the read/write transmit buffer register, txregx. the txregx register is loaded with data in software. the tsr register is not loaded until the last bit has been transmitted from the previous load. as soon as the last bit is transmitted, the tsr is loaded with new data from the txregx (if available). once the txregx register transfers the data to the tsr register (occurs in one t cy ), the txregx is empty and the txxif flag bit is set. the interrupt can be enabled or disabled by setting or clearing the interrupt enable bit, txxie. txxif is set regardless of the state of enable bit, txxie; it cannot be cleared in software. it will reset only when new data is loaded into the txregx register. while flag bit, txxif, indicates the status of the txregx register, another bit, trmt (txstax<1>), shows the status of the tsr register. trmt is a read-only bit which is set when the tsr is empty. no interrupt logic is tied to this bit, so the user must poll this bit in order to determine if the tsr register is empty. the tsr is not mapped in data memory so it is not available to the user. to set up a synchronous master transmission: 1. initialize the spbrghx:spbrgx registers for the appropriate baud rate. set or clear the brg16 bit, as required, to achieve the desired baud rate. 2. enable the synchronous master serial port by setting bits, sync, spen and csrc. 3. if interrupts are desired, set enable bit, txxie. 4. if 9-bit transmission is desired, set bit, tx9. 5. enable the transmission by setting bit, txen. 6. if 9-bit transmission is selected, the ninth bit should be loaded in bit, tx9d. 7. start transmission by loading data to the txregx register. 8. if using interrupts, ensure that the gie and peie bits in the intcon register (intcon<7:6>) are set. figure 22-11: synchronous transmission bit 0 bit 1 bit 7 word 1 q1 q2 q3q4 q1 q2 q3 q4 q1 q2 q3 q4 q1q2 q3 q4 q1 q2 q3 q4 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 bit 2 bit 0 bit 1 bit 7 pin rc6/tx1/ck1/ write to txreg1 reg tx1if bit (interrupt flag) txen bit 1 1 word 2 trmt bit write word 1 write word 2 note: sync master mode, spbrgx = 0 , continuous transmission of two 8-bit words. this example is equally applicable to eusart2 (rg1/tx2/ck2/an19/c3out and rg2/rx2/dt2/an18/c3ina). rc7/rx1/dt1/ pin (txckp = 0 ) rc6/tx1/ck1/ pin (txckp = 1 ) downloaded from: http:///
pic18f87k22 family ds39960d-page 346 ? 2009-2011 microchip technology inc. figure 22-12: synchronous transmis sion (through txen) table 22-7: registers associated with synchronous master transmission name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir1 pspif adif rc1if tx1if ssp1if tmr1gif tmr2if tmr1if pie1 pspie adie rc1ie tx1ie ssp1ie tmr1gie tmr2ie tmr1ie ipr1 pspip adip rc1ip tx1ip ssp1ip tmr1gip tmr2ip tmr1ip pir3 tmr5gif rc2if tx2if ctmuif ccp2if ccp1if rtccif pie3 tmr5gie rc2ie tx2ie ctmuie ccp2ie ccp1ie rtccie ipr3 tmr5gip rc2ip tx2ip ctmuip ccp2ip ccp1ip rtccip rcsta1 spen rx9 sren cren adden ferr oerr rx9d txreg1 eusart1 transmit register txsta1 csrc tx9 txen sync sendb brgh trmt tx9d baudcon1 abdovf rcidl rxdtp txckp brg16 wue abden spbrgh1 eusart1 baud rate generator register high byte spbrg1 eusart1 baud rate generator register rcsta2 spen rx9 sren cren adden ferr oerr rx9d txreg2 eusart2 transmit register txsta2 csrc tx9 txen sync sendb brgh trmt tx9d baudcon2 abdovf rcidl rxdtp txckp brg16 wue abden spbrgh2 eusart2 baud rate generator register high byte spbrg2 eusart2 baud rate generator register odcon3 u2od u1od ctmuds pmd0 ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd legend: = unimplemented, read as 0 . shaded cells are not used for synchronous master transmission. rc7/rx1/dt1 pin rc6/tx1/ck1 pin write to txreg1 reg tx1if bit trmt bit bit 0 bit 1 bit 2 bit 6 bit 7 txen bit note: this example is equally applicable to eusart2 (rg1/tx2/ck2/an19/c3out and rg2/rx2/dt2/an18/c3ina). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 347 pic18f87k22 family 22.3.2 eusart synchronous master reception once synchronous mode is selected, reception is enabled by setting either the single receive enable bit, sren (rcstax<5>), or the continuous receive enable bit, cren (rcstax<4>). data is sampled on the rxx pin on the falling edge of the clock. if enable bit, sren, is set, only a single word is received. if enable bit, cren, is set, the reception is continuous until cren is cleared. if both bits are set, then cren takes precedence. to set up a synchronous master reception: 1. initialize the spbrghx:spbrgx registers for the appropriate baud rate. set or clear the brg16 bit, as required, to achieve the desired baud rate. 2. enable the synchronous master serial port by setting bits, sync, spen and csrc. 3. ensure bits, cren and sren, are clear. 4. if interrupts are desired, set enable bit, rcxie. 5. if 9-bit reception is desired, set bit, rx9. 6. if a single reception is required, set bit, sren. for continuous reception, set bit, cren. 7. interrupt flag bit, rcxif, will be set when recep- tion is complete and an interrupt will be generated if the enable bit, rcxie, was set. 8. read the rcstax register to get the 9th bit (if enabled) and determine if any error occurred during reception. 9. read the 8-bit received data by reading the rcregx register. 10. if any error occurred, clear the error by clearing bit cren. 11. if using interrupts, ensure that the gie and peie bits in the intcon register (intcon<7:6>) are set. figure 22-13: synchronous reception (master mode, sren) cren bit write to bit, sren sren bit rc1if bit (interrupt) read rcreg1 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q2 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 0 bit 0 bit 1 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7 0 q1 q2 q3 q4 note: timing diagram demonstrates sync master mode with bit, sren = 1, and bit, brgh = 0 . this example is equally applicable to eusart2 (rg1/tx2/ck2/an19/c3out and rg2/rx2/dt2/an18/c3ina). pin rc7/rx1/dt1 rc6/tx1/ck1 pin (txckp = 0 ) rc6/tx1/ck1 pin (txckp = 1 ) downloaded from: http:///
pic18f87k22 family ds39960d-page 348 ? 2009-2011 microchip technology inc. table 22-8: registers associated with synchronous master reception name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir1 pspif adif rc1if tx1if ssp1if tmr1gif tmr2if tmr1if pie1 pspie adie rc1ie tx1ie ssp1ie tmr1gie tmr2ie tmr1ie ipr1 pspip adip rc1ip tx1ip ssp1ip tmr1gip tmr2ip tmr1ip pir3 tmr5gif r c 2 i f tx2if ctmuif ccp2if ccp1if rtccif pie3 tmr5gie r c 2 i e tx2ie ctmuie ccp2ie ccp1ie rtccie ipr3 tmr5gip r c 2 i p tx2ip ctmuip ccp2ip ccp1ip rtccip rcsta1 spen rx9 sren cren adden ferr oerr rx9d rcreg1 eusart1 receive register txsta1 csrc tx9 txen sync sendb brgh trmt tx9d baudcon1 abdovf rcidl rxdtp txckp brg16 wue abden spbrgh1 eusart1 baud rate generator register high byte spbrg1 eusart1 baud rate generator register rcsta2 spen rx9 sren cren adden ferr oerr rx9d rcreg2 eusart2 receive register txsta2 csrc tx9 txen sync sendb brgh trmt tx9d baudcon2 abdovf rcidl rxdtp txckp brg16 wue abden spbrgh2 eusart2 baud rate generator register high byte spbrg2 eusart2 baud rate generator register odcon3 u2od u1od ctmuds pmd0 ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd legend: = unimplemented, read as 0 . shaded cells are not used for synchronous master reception. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 349 pic18f87k22 family 22.4 eusart synchronous slave mode synchronous slave mode is entered by clearing bit, csrc (txstax<7>). this mode differs from the synchronous master mode in that the shift clock is sup- plied externally at the ckx pin (instead of being supplied internally in master mode). this allows the device to transfer or receive data while in any low-power mode. 22.4.1 eusart synchronous slave transmission the operation of the synchronous master and slave modes is identical, except in the case of sleep mode. if two words are written to the txregx and then the sleep instruction is executed, the following will occur: a) the first word will immediately transfer to the tsr register and transmit. b) the second word will remain in the txregx register. c) flag bit, txxif, will not be set. d) when the first word has been shifted out of tsr, the txregx register will transfer the second word to the tsr and flag bit, txxif, will now be set. e) if enable bit, txxie, is set, the interrupt will wake the chip from sleep. if the global interrupt is enabled, the program will branch to the interrupt vector. to set up a synchronous slave transmission: 1. enable the synchronous slave serial port by setting bits, sync and spen, and clearing bit, csrc. 2. clear bits, cren and sren. 3. if interrupts are desired, set enable bit, txxie. 4. if 9-bit transmission is desired, set bit, tx9. 5. enable the transmission by setting enable bit, txen. 6. if 9-bit transmission is selected, the ninth bit should be loaded in bit, tx9d. 7. start transmission by loading data to the txregx register. 8. if using interrupts, ensure that the gie and peie bits in the intcon register (intcon<7:6>) are set. table 22-9: registers associated with synchronous slave transmission name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir1 pspif adif rc1if tx1if ssp1if tmr1gif tmr2if tmr1if pie1 pspie adie rc1ie tx1ie ssp1ie tmr1gie tmr2ie tmr1ie ipr1 pspip adip rc1ip tx1ip ssp1ip tmr1gip tmr2ip tmr1ip pir3 tmr5gif rc2if tx2if ctmuif ccp2if ccp1if rtccif pie3 tmr5gie rc2ie tx2ie ctmuie ccp2ie ccp1ie rtccie ipr3 tmr5gip rc2ip tx2ip ctmuip ccp2ip ccp1ip rtccip rcsta1 spen rx9 sren cren adden ferr oerr rx9d txreg1 eusart1 transmit register txsta1 csrc tx9 txen sync sendb brgh trmt tx9d baudcon1 abdovf rcidl rxdtp txckp brg16 wue abden spbrgh1 eusart1 baud rate generator register high byte spbrg1 eusart1 baud rate generator register rcsta2 spen rx9 sren cren adden ferr oerr rx9d txreg2 eusart2 transmit register txsta2 csrc tx9 txen sync sendb brgh trmt tx9d baudcon2 abdovf rcidl rxdtp txckp brg16 wue abden spbrgh2 eusart2 baud rate generator register high byte spbrg2 eusart2 baud rate generator register odcon3 u2od u1od ctmuds pmd0 ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd legend: = unimplemented, read as 0 . shaded cells are not used for synchronous slave transmission. downloaded from: http:///
pic18f87k22 family ds39960d-page 350 ? 2009-2011 microchip technology inc. 22.4.2 eusart synchronous slave reception the operation of the synchronous master and slave modes is identical except in the case of sleep, or any idle mode, and bit, sren, which is a dont care in slave mode. if receive is enabled by setting the cren bit prior to entering sleep or any idle mode, then a word may be received while in this low-power mode. once the word is received, the rsr register will transfer the data to the rcregx register. if the rcxie enable bit is set, the interrupt generated will wake the chip from the low-power mode. if the global interrupt is enabled, the program will branch to the interrupt vector. to set up a synchronous slave reception: 1. enable the synchronous master serial port by setting bits, sync and spen, and clearing bit, csrc. 2. if interrupts are desired, set enable bit, rcxie. 3. if 9-bit reception is desired, set bit, rx9. 4. to enable reception, set enable bit, cren. 5. flag bit, rcxif, will be set when reception is complete. an interrupt will be generated if enable bit, rcxie, was set. 6. read the rcstax register to get the 9th bit (if enabled) and determine if any error occurred during reception. 7. read the 8-bit received data by reading the rcregx register. 8. if any error occurred, clear the error by clearing bit, cren. 9. if using interrupts, ensure that the gie and peie bits in the intcon register (intcon<7:6>) are set. table 22-10: registers associated wi th synchronous slave reception name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir1 pspif adif rc1if tx1if ssp1if tmr1gif tmr2if tmr1if pie1 pspie adie rc1ie tx1ie ssp1ie tmr1gie tmr2ie tmr1ie ipr1 pspip adip rc1ip tx1ip ssp1ip tmr1gip tmr2ip tmr1ip pir3 tmr5gif rc2if tx2if ctmuif ccp2if ccp1if rtccif pie3 tmr5gie rc2ie tx2ie ctmuie ccp2ie ccp1ie rtccie ipr3 tmr5gip rc2ip tx2ip ctmuip ccp2ip ccp1ip rtccip rcsta1 spen rx9 sren cren adden ferr oerr rx9d rcreg1 eusart1 receive register txsta1 csrc tx9 txen sync sendb brgh trmt tx9d baudcon1 abdovf rcidl rxdtp txckp brg16 wue abden spbrgh1 eusart1 baud rate generator register high byte spbrg1 eusart1 baud rate generator register rcsta2 spen rx9 sren cren adden ferr oerr rx9d rcreg2 eusart2 receive register txsta2 csrc tx9 txen sync sendb brgh trmt tx9d baudcon2 abdovf rcidl rxdtp txckp brg16 wue abden spbrgh2 eusart2 baud rate generator register high byte spbrg2 eusart2 baud rate generator register odcon3 u2od u1od ctmuds pmd0 ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd legend: = unimplemented, read as 0 . shaded cells are not used for synchronous slave reception. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 351 pic18f87k22 family 23.0 12-bit analog-to-digital converter (a/d) module the analog-to-digital (a/d) converter module in the pic18f87k22 family of devices has 16 inputs for the 64-pin devices and 24 inputs for the 80-pin devices. this module allows conversion of an analog input signal to a corresponding 12-bit digital number. the module has these registers: a/d control register 0 (adcon0) a/d control register 1 (adcon1) a/d control register 2 (adcon2) a/d port configuration register 0 (ancon0) a/d port configuration register 1 (ancon1) a/d port configuration register 2 (ancon2) adresh (the upper, a/d results register) adresl (the lower, a/d results register) the adcon0 register, shown in register 23-1 , con- trols the operation of the a/d module. the adcon1 register, shown in register 23-2 , configures the voltage reference and special trigger selection. the adcon2 register, shown in register 23-3 , configures the a/d clock source and programmed acquisition time and justification. 23.1 differential a/d converter the converter in pic18f87k22 family devices is implemented as a differential a/d where the differential voltage between two channels is measured and converted to digital values (see figure 23-1 ). the converter can also be configured to measure a voltage from a single input by clearing the chsn bits (adcon1<2:0>). with this configuration, the negative channel input is connected internally to av ss (see figure 23-2 ). figure 23-1: differential channel measurement differential conversion feeds the two input channels to a unity gain differential amplifier. the positive channel input is selected using the chs bits (adcon0<6:2>) and the negative channel input is selected using the chsn bits (adcon1<2:0>). the output from the amplifier is fed to the a/d con- verter, as shown in figure 23-1 . the 12-bit result is available on the adresh and adresl registers. an additional bit indicates if the 12-bit result is a positive or negative value. figure 23-2: single channel measurement in the single channel measurement mode, the nega- tive input is connected to a vss by clearing the chsn bits (adcon1<2:0>). adc positive input chs<4:0> negative input chsn<2:0> adc positive input chs<4:0> chsn<2:0> = 000 downloaded from: http:///
pic18f87k22 family ds39960d-page 352 ? 2009-2011 microchip technology inc. 23.2 a/d registers 23.2.1 a/d control registers register 23-1: adcon0: a/ d control register 0 u-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 chs4 chs3 chs2 chs1 chs0 go/done adon bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 unimplemented: read as 0 bit 6-2 chs<4:0>: analog channel select bits 00000 = channel 00 (an0) 10000 = channel 16 (an16) 00001 = channel 01 (an1) 10001 = channel 17 (an17) 00010 = channel 02 (an2) 10010 = channel 18 (an18) 00011 = channel 03 (an3) 10011 = channel 19 (an19) 00100 = channel 04 (an4) 10100 = channel 20 (an20) ( 1 , 2 ) 00101 = channel 05 (an5) 10101 = channel 21 (an21) ( 1 , 2 ) 00110 = channel 06 (an6) 10110 = channel 22 (an22) ( 1 , 2 ) 00111 = channel 07 (an7) 10111 = channel 23 (an23) ( 1 , 2 ) 01000 = channel 08 (an8) 11000 =(reserved) ( 2 ) 01001 = channel 09 (an9) 11001 =(reserved) ( 2 ) 01010 = channel 10 (an10 11010 =(reserved) ( 2 ) 01011 = channel 11 (an11) 11011 =(reserved) ( 2 ) 01100 = channel 12 (an12) ( 1 , 2 ) 11100 = channel 28 (reserved ctmu) 01101 = channel 13 (an13) ( 1 , 20 ) 11101 = channel 29 (internal temperature diode) 01110 = channel 14 (an14) ( 1 , 2 ) 11110 = channel 30 (v ddcore ) 01111 = channel 15 (an15) ( 1 , 2 ) 11111 = channel 31 (v1.024v band gap) bit 1 go/done : a/d conversion status bit 1 = a/d (or calibration) cycle in progress. setting this bit starts an a/d conversion cycle. the bit is cleared automatically by hardware when the a/d conversion is completed. 0 = a/d conversion has completed or is not in progress bit 0 adon: a/d on bit 1 = a/d converter is operating 0 = a/d conversion module is shut off and consuming no operating current note 1: these channels are not implemented on 64-pin devices. 2: performing a conversion on unimplemented channels will return random values. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 353 pic18f87k22 family register 23-2: adcon1: a/ d control register 1 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 trigsel1 trigsel0 vcfg1 vcfg0 vncfg chsn2 chsn1 chsn0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-6 trigsel<1:0>: special trigger select bits 11 = selects the special trigger from the rtcc 10 = selects the special trigger from the timer1 01 = selects the special trigger from the ctmu 00 = selects the special trigger from the eccp2 bit 5-4 vcfg<1:0>: a/d v ref + configuration bits 11 = internal v ref + (4.096v) 10 = internal v ref + (2.048v) 01 = external v ref + 00 = av dd bit 3 vncfg: a/d v ref - configuration bit 1 =external v ref 0 =av ss bit 2-0 chsn<2:0>: analog negative channel select bits 111 = channel 07 (an6) 110 = channel 06 (an5) 101 = channel 05 (an4) 100 = channel 04 (an3) 011 = channel 03 (an2) 010 = channel 02 (an1) 001 = channel 01 (an0) 000 = channel 00 (av ss ) downloaded from: http:///
pic18f87k22 family ds39960d-page 354 ? 2009-2011 microchip technology inc. register 23-3: adcon2: a/ d control register 2 r/w-0 u-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 adfm acqt2 acqt1 acqt0 adcs2 adcs1 adcs0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 adfm: a/d result format select bit 1 = right justified 0 = left justified bit 6 unimplemented: read as 0 bit 5-3 acqt<2:0>: a/d acquisition time select bits 111 = 20 t ad 110 = 16 t ad 101 = 12 t ad 100 = 8 t ad 011 = 6 t ad 010 = 4 t ad 001 = 2 t ad 000 = 0 t ad ( 1 ) bit 2-0 adcs<2:0>: a/d conversion clock select bits 111 = f rc (clock derived from a/d rc oscillator) ( 1 ) 110 = f osc /64 101 = f osc /16 100 = f osc /4 011 = f rc (clock derived from a/d rc oscillator) ( 1 ) 010 = f osc /32 001 = f osc /8 000 = f osc /2 note 1: if the a/d frc clock source is selected, a delay of one t cy (instruction cycle) is added before the a/d clock starts. this allows the sleep instruction to be executed before starting a conversion. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 355 pic18f87k22 family 23.2.2 a/d result registers the adresh:adresl register pair is where the 12-bit a/d result and extended sign bits (adsgn) are loaded at the completion of a conversion. this register pair is 16 bits wide. the a/d module gives the flexibility of left or right justifying the 12-bit result in the 16-bit result register. the a/d format select bit (adfm) controls this justification. figure 23-3 shows the operation of the a/d result justi- fication and location of the extended sign bits (adsgn). the extended sign bits allow for easier 16-bit math to be performed on the result . the results are represented as a two's compliment binary valu e. this means that when sign bits and magnitude bits are considered together in right justification, the adresh and adresl registers can be read as a single signed integer value. when the a/d converter is disabled, these 8-bit registers can be used as tw o general purpose registers. figure 23-3: a/d result justification result bits adsgn bit adresh adresl adresh adresl 12-bit result left justified adfm = 0 right justified adfm = 1 twos complement example results number line left justified right justified hex decimal hex decimal 0xfff0 4095 0x0fff 4095 0xffe0 4094 0x0ffe 4094 0x0020 2 0x0002 2 0x0010 1 0x0001 1 0x0000 0 0x0000 0 0xffff -1 0xffff -1 0xffef -2 0xfffe -2 0x001f -4095 0xf001 -4095 0x000f -4096 0xf000 -4096 downloaded from: http:///
pic18f87k22 family ds39960d-page 356 ? 2009-2011 microchip technology inc. register 23-4: adresh: a/d result high byte register, left justified (adfm = 0 ) r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x adres11 adres10 adres9 adres8 adres7 adres6 adres5 adres4 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-0 adres<11:4>: a/d result high byte bits register 23-5: adresl: a/d result high byte register, left justified (adfm = 0 ) r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x adres3 adres2 adres1 adres0 adsgn adsgn adsgn adsgn bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-4 adres<3:0>: a/d result low byte bits bit 3-0 adsgn: a/d result sign bit 1 = a/d result is negative 0 = a/d result is positive downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 357 pic18f87k22 family register 23-6: adresh: a/d result high byte register, right justified (adfm = 1 ) r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x adsgn adsgn adsgn adsgn adres11 adres10 adres9 adres8 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-4 adsgn: a/d result sign bit 1 = a/d result is negative 0 = a/d result is positive bit 3-0 adresh<11:8>: a/d result high byte bits register 23-7: adresl: a/d result low byte register, right justified (adfm = 1 ) r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x r/w-x adres7 adres6 adres5 adres4 adres3 adres2 adres1 adres0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-0 adres<7:0>: a/d result low byte bits downloaded from: http:///
pic18f87k22 family ds39960d-page 358 ? 2009-2011 microchip technology inc. the anconx registers are used to configure the operation of the i/o pin associated with each analog channel. clearing an anselx bit configures the corresponding pin (anx) to operate as a digital only i/o. setting a bit configures the pin to operate as an analog input for either the a/d converter or the comparator module, with all digital peripherals disabled and digital inputs read as 0 . as a rule, i/o pins that are multiplexed with analog inputs default to analog operation on any device reset. register 23-8: ancon0: a/d port configuration register 0 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 ansel7 ansel6 ansel5 ansel4 a nsel3 ansel2 ansel1 ansel0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-0 ansel<7:0>: analog port configuration bits (an7 and an0) 1 = pin is configured as an analog channel; digital input is disabled and any inputs read as 0 0 = pin is configured as a digital port register 23-9: ancon1: a/d port configuration register 1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 ansel15 ( 1 ) ansel14 ( 1 ) ansel13 ( 1 ) ansel12 ( 1 ) ansel11 ansel10 ansel9 ansel8 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-0 ansel<15:8>: analog port configuration bits (an15 through an8) ( 1 ) 1 = pin is configured as an analog channel; digital input is disabled and any inputs read as 0 0 = pin is configured as a digital port note 1: an15 through an12 and an23 to an20 are implemented only on 80-pin devices. for 64-pin devices, the corresponding anselx bits are still implemented for these channels, but have no effect. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 359 pic18f87k22 family the analog reference voltage is software-selectable to either the devices positive and negative supply voltage (av dd and av ss ) or the voltage level on the ra3/an3/v ref + and ra2/an2/v ref - pins. v ref + has two additional internal reference voltage selections: 2.048v and 4.096v. the a/d converter can uniquely operate while the device is in sleep mode. to operate in sleep, the a/d conversion clock must be derived from the a/d converters internal rc oscillator. the output of the sample-and-hold (s/h) is the input into the converter, which generates the result via successive approximation. each port pin associated with the a/d converter can be configured as an analog input or a digital i/o. the adresh and adresl registers contain the result of the a/d conversion. when the a/d conversion is com- plete, the result is loaded into the adresh:adresl register pair, the go/done bit (adcon0<1>) is cleared and the a/d interrupt flag bit, adif (pir1<6>), is set. a device reset forces all registers to their reset state. this forces the a/d module to be turned off and any conversion in progress is aborted. the value in the adresh:adresl register pair is not modified for a power-on reset. these registers will contain unknown data after a power-on reset. the block diagram of the a/d module is shown in figure 23-4 . register 23-10: ancon2: a/d port configuration register 2 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 r/w-1 ansel23 ( 1 ) ansel22 ( 1 ) ansel21 ( 1 ) ansel20 ( 1 ) ansel19 ansel18 ansel17 ansel16 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-0 ansel<23:16>: analog port configuration bits (an23 through an16) ( 1 ) 1 = pin is configured as an analog channel; digital input is disabled and any inputs read as 0 0 = pin is configured as a digital port note 1: an15 through an12 and an23 through an20 are implemented only on 80-pin devices. for 64-pin devices, the corresponding anselx bits are still implemented for these channels, but have no effect. downloaded from: http:///
pic18f87k22 family ds39960d-page 360 ? 2009-2011 microchip technology inc. figure 23-4: a/d block diagram v ref + reference voltage vncfg chs<4:0> an23 (1) an22 (1) an4an3 an2 an1 an0 1011110110 00100 00011 00010 00001 00000 12-bit a/d v ref - v ss (2) converter 1.024v band gap v ddcore reserved ctmu (unimplemented) 11111 11110 11101 11100 11011 11010 11001 11000 note 1: channels, an15 through an12, and an20 through an23, are not available on 64-pin devices. 2: i/o pins have diode protection to v dd and v ss . (unimplemented) (unimplemented) (unimplemented) negative input voltage positive input voltage chsn<2:0> an6 an5 an0 av ss 111110 001 000 an2 vcfg<1:0> an3 v dd 1110 01 00 internal v ref + (4.096v) internal v ref + (2.048v) reserved temperature diode downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 361 pic18f87k22 family after the a/d module has been configured as desired, the selected channel must be acquired before the conversion can start. the analog input channels must have their corresponding tris bits selected as inputs. to determine acquisition time, see section 23.3 a/d acquisition requirements . after this acquisition time has elapsed, the a/d conversion can be started. an acquisition time can be programmed to occur between setting the go/done bit and the actual start of the conversion. to do an a/d conversion, follow these steps: 1. configure the a/d module: configure the required adc pins as analog pins (ancon0, ancon1 and ancon2) set the voltage reference (adcon1) select the a/d positive and negative input channels (adcon0 and adcon1) select the a/d acquisition time (adcon2) select the a/d conversion clock (adcon2) turn on the a/d module (adcon0) 2. configure the a/d interrupt (if desired): clear the adif bit (pir1<6>) set the adie bit (pie1<6>) set the gie bit (intcon<7>) 3. wait the required acquisition time (if required). 4. start the conversion: set the go/done bit (adcon0<1>) 5. wait for a/d conversion to complete, by either: polling for the go/done bit to be cleared or waiting for the a/d interrupt 6. read a/d result registers (adresh:adresl) and, if required, clear bit, adif. 7. for the next conversion, begin with step 1 or 2, as required. the a/d conversion time per bit is defined as t ad . before the next acquisition starts, a minimum wait of 2 t ad is required. figure 23-5: analog input model v ain c pin r s anx 5 pf v dd v t = 0.6v v t = 0.6v i leakage r ic ?? 1k sampling switch ss r ss c hold = 25 pf v ss sampling switch 123 4 (k ? ) v dd 100 na legend: c pin v t i leakage r ic ssc hold = input capacitance = threshold voltage = leakage current at the pin due to = interconnect resistance = sampling switch = sample/hold capacitance (from dac) various junctions = sampling switch resistance r ss downloaded from: http:///
pic18f87k22 family ds39960d-page 362 ? 2009-2011 microchip technology inc. 23.3 a/d acquisition requirements for the a/d converter to meet its specified accuracy, the charge holding (c hold ) capacitor must be allowed to fully charge to the input channel voltage level. the analog input model is shown in figure 23-5 . the source impedance (r s ) and the internal sampling switch (r ss ) impedance directly affect the time required to charge the capacitor c hold . the sampling switch (r ss ) impedance varies over the device voltage (v dd ). the source impedance affects the offset voltage at the analog input (due to pin leakage current). the maxi- mum recommended impedance for analog sources is 2.5 k ? . after the analog input channel is selected or changed, the channel must be sampled for at least the minimum acquisition time before starting a conversion. to calculate the minimum acquisition time, equation 23-1 can be used. this equation assumes that 1/2 lsb error is used (1,024 steps for the a/d). the 1/2 lsb error is the maximum error allowed for the a/d to meet its specified resolution. equation 23-3 shows the calculation of the minimum required acquisition time, t acq . this calculation is based on the following application system assumptions: equation 23-1: acquisition time equation 23-2: a/d minimum charging time equation 23-3: calculating the minimum required acquisition time note: when the conversion is started, the holding capacitor is disconnected from the input pin. c hold =25 pf rs = 2.5 k ?? conversion error ? 1/2 lsb v dd =3v ? rss = 2 k ? temperature = 85 ? c t acq = amplifier settling time + holding capacitor charging time + temperature coefficie nt =t amp + t c + t coff v hold = (v ref C (v ref /2048)) (1 C e (-t c /c hold (r ic + r ss + r s )) ) or t c = -(c hold )(r ic + r ss + r s ) ln(1/2048) t acq =t amp + t c + t coff t amp =0.2 ? s t coff = (temp C 25 ? c)(0.02 ? s/ ? c) (85 ? c C 25 ? c)(0.02 ? s/ ? c) 1.2 ? s temperature coefficient is only required for temperatures > 25 ? c. below 25 ? c, t coff = 0 ms. t c = -(c hold )(r ic + r ss + r s ) ln(1/2048) ? s -(25 pf) (1 k ? + 2 k ? + 2.5 k ? ) ln(0.0004883) ? s 1.05 ? s t acq =0.2 ? s + 1.05 ? s + 1.2 ? s 2.45 ? s downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 363 pic18f87k22 family 23.4 selecting and configuring automatic acquisition time the adcon2 register allows the user to select an acquisition time that occurs each time the go/done bit is set. when the go/done bit is set, sampling is stopped and a conversion begins. the user is responsible for ensur- ing the required acquisition time has passed between selecting the desired input channel and setting the go/done bit. this occurs when the acqt<2:0> bits (adcon2<5:3>) remain in their reset state ( 000 ), which is compatible with devices that do not offer programmable acquisition times. if desired, the acqtx bits can be set to select a pro- grammable acquisition time for the a/d module. when the go/done bit is set, the a/d module continues to sample the input for the selected acquisition time, then automatically begins a conversion. since the acquisi- tion time is programmed, there may be no need to wait for an acquisition time between selecting a channel and setting the go/done bit. in either case, when the conversion is completed, the go/done bit is cleared, the adif flag is set and the a/d begins sampling the currently selected channel again. if an acquisition time is programmed, there is nothing to indicate if the acquisition time has ended or if the conversion has begun. 23.5 selecting the a/d conversion clock the a/d conversion time per bit is defined as t ad . the a/d conversion requires 14 t ad per 12-bit conversion. the source of the a/d conversion clock is software-selectable. the possible options for t ad are: 2 t osc 4 t osc 8 t osc 16 t osc 32 t osc 64 t osc using the internal rc oscillator for correct a/d conversions, the a/d conversion clock (t ad ) must be as short as possible, but greater than the minimum t ad . (for more information, see parameter 130 in table 31-28 .) table 23-1 shows the resultant t ad times derived from the device operating frequencies and the a/d clock source selected. table 23-1: t ad vs. device operating frequencies 23.6 configuring analog port pins the ancon0, ancon1, ancon2, trisa, trisf, trisg and trish registers control the operation of the a/d port pins. the port pins needed as analog inputs must have their corresponding trisx bits set (input). if the trisx bit is cleared (output), the digital output level (v oh or v ol ) will be converted. the a/d operation is independent of the state of the chs<3:0> bits and the trisx bits. ad clock source (t ad )m a x i m u m device frequency operation adcs<2:0> 2 t osc 000 2.50 mhz 4 t osc 100 5.00 mhz 8 t osc 001 10.00 mhz 16 t osc 101 20.00 mhz 32 t osc 010 40.00 mhz 64 t osc 110 64.00 mhz rc ( 2 ) x11 1.00 mhz ( 1 ) note 1: the rc source has a typical t ad time of 4 ? s. 2: for device frequencies above 1 mhz, the device must be in sleep mode for the entire conversion or the a/d accuracy may be out of specification. note 1: when reading the port register, all pins configured as analog input channels will read as cleared (a low level). pins config- ured as digital inputs will convert an analog input. analog levels on a digitally configured input will be accurately converted. 2: analog levels on any pin defined as a digital input may cause the digital input buffer to consume current out of the devices specification limits. downloaded from: http:///
pic18f87k22 family ds39960d-page 364 ? 2009-2011 microchip technology inc. 23.7 a/d conversions figure 23-6 shows the operation of the a/d converter after the go/done bit has been set and the acqt<2:0> bits are cleared. a conversion is started after the following instruction to allow entry into sleep mode before the conversion begins. figure 23-7 shows the operation of the a/d converter after the go/done bit has been set, the acqt<2:0> bits set to 010 and a 4 t ad acquisition time selected. clearing the go/done bit during a conversion will abort the current conversion. the a/d result register pair will not be updated with the partially completed a/d conversion sample. this means the adresh:adresl registers will continue to contain the value of the last completed conversion (or the last value written to the adresh:adresl registers). after the a/d conversion is completed or aborted, a 2t ad wait is required before the next acquisition can be started. after this wait, acquisition on the selected channel is automatically started. figure 23-6: a/d conversion t ad cycles (acqt<2:0> = 000 , t acq = 0 ) figure 23-7: a/d conversion t ad cycles (acqt<2:0> = 010 , t acq = 4 t ad ) note: the go/done bit should not be set in the same instruction that turns on the a/d. t ad 1 t ad 2 t ad 3 t ad 4t ad 5 t ad 6 t ad 7 t ad 8 t ad 11 set go/done bit holding capacitor is disconnected from analog input (typically 100 ns) t ad 9 t ad 10 t cy - t ad next q4: adresh:adresl is loaded, go/done bit is cleared, adif bit is set, holding capacitor is connected to analog input. conversion starts b2 b11 b8 b7 b6 b5 b4 b3 b10 b9 t ad 13 t ad 12 b0 b1 1 2 3 4 5 6 7 8 11 set go/done bit (holding capacitor is disconnected) 9 10 next q4: adresh:adresl is loaded, go/done bit is cleared, adif bit is set, holding capacitor is reconnected to analog input. conversion starts 1 2 3 4 (holding capacitor continues acquiring input) t acqt cycles t ad cycles automatic acquisition time b2 b11 b8 b7 b6 b5 b4 b3 b10 b9 13 12 b0 b1 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 365 pic18f87k22 family 23.8 use of the special event triggers a/d conversion can be started by the special event trigger of any of these modules: eccp2 C requires ccp2m<3:0> bits (ccp2con<3:0>) set at 1011 ctmu C requires the setting of the cttrig bit (ctmuconh<0>) timer1 rtcc to start an a/d conversion: the a/d module must be enabled (adon = 1 ) the appropriate analog input channel is selected the minimum acquisition period is set one of these ways: - timing provided by the user - selection made of an appropriate t acq time with these conditions met, the trigger sets the go/done bit and the a/d acquisition starts. if the a/d module is not enabled (adon = 0 ), the module ignores the special event trigger. 23.9 operation in power-managed modes the selection of the automatic acquisition time and a/d conversion clock is determined, in part, by the clock source and frequency while in a power-managed mode. if the a/d is expected to operate while the device is in a power-managed mode, the acqt<2:0> and adcs<2:0> bits in adcon2 should be updated in accordance with the power-managed mode clock that will be used. after the power-managed mode is entered (either of the power-managed run modes), an a/d acquisition or conversion may be started. once an acquisition or con- version is started, the device should continue to be clocked by the same power-managed mode clock source until the conversion has been completed. if desired, the device may be placed into the corresponding power-managed idle mode during the conversion. if the power-managed mode clock frequency is less than 1 mhz, the a/d rc clock source should be selected. operation in sleep mode requires that the a/d rc clock be selected. if bits, acqt<2:0>, are set to 000 and a conversion is started, the conversion will be delayed one instruction cycle to allow execution of the sleep instruction and entry into sleep mode. the idlen and scs<1:0> bits in the osccon register must have already been cleared prior to starting the conversion. note: with an eccp2 trigger, timer1 or timer 3 is cleared. the timers reset to automati- cally repeat the a/d acquisition period with minimal software overhead (moving adresh:adresl to the desired loca- tion). if the a/d module is not enabled, the special event trigger is ignored by the module, but the timers counter resets. downloaded from: http:///
pic18f87k22 family ds39960d-page 366 ? 2009-2011 microchip technology inc. table 23-2: registers associat ed with a/d module name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir1 pspif adif rc1if tx1if ssp1if tmr1gif tmr2if tmr1if pie1 pspie adie rc1ie tx1ie ssp1ie tmr1gie tmr2ie tmr1ie ipr1 pspip adip rc1ip tx1ip ssp1ip tmr1gip tmr2ip tmr1ip pir3 tmr5gif rc2if tx2if ctmuif ccp2if ccp1if rtccif pie3 tmr5gie rc2ie tx2ie ctmuie ccp2ie ccp1ie rtccie ipr3 tmr5gip rc2ip tx2ip ctmuip ccp2ip ccp1ip rtccip adresh a/d result register high byte adresl a/d result register low byte adcon0 chs4 chs3 chs2 chs1 chs0 go/done adon adcon1 trigsel1 trigsel0 vcfg1 vcfg0 vncfg chsn2 chsn1 chsn0 adcon2 adfm acqt2 acqt1 acqt0 adcs2 adcs1 adcs0 ancon0 ansel7 ansel6 ansel5 ansel 4 ansel3 ansel2 ansel1 ansel0 ancon1 ansel15 ansel14 ansel13 ansel 12 ansel11 ansel10 ansel9 ansel8 ancon2 ansel23 ansel22 ansel21 ansel 20 ansel19 ansel18 ansel17 ansel16 ccp2con p2m1 p2m0 dc2b1 dc2b0 ccp2m3 ccp2m2 ccp2m1 ccp2m0 porta ra7 ( 2 ) ra6 ( 2 ) ra5 ra4 ra3 ra2 ra1 ra0 trisa trisa7 ( 2 ) trisa6 ( 2 ) trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 portf rf7 rf6 rf5 rf4 rf3 rf2 rf1 trisf trisf7 trisf6 trisf5 t risf4 trisf3 trisf2 trisf1 portg rg5 ( 3 ) rg4 rg3 rg2 rg1 rg0 trisg trisg4 trisg3 trisg2 trisg1 trisg0 porth ( 1 ) rh7 rh6 rh5 rh4 rh3 rh2 rh1 rh0 trish ( 1 ) trish7 trish6 trish5 trish4 trish3 trish2 trish1 trish0 pmd0 ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd legend: = unimplemented, read as 0 . shaded cells are not used for a/d conversion. note 1: this register is not implemented on 64-pin devices. 2: these bits are available only in certain oscillator modes, when the fosc2 configuration bit = 0 . if that configuration bit is cleared, this signal is not implemented. 3: this bit is available when master clear is disabled (mclre = 0 ). when mclre is set, the bit is unimplemented. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 367 pic18f87k22 family 24.0 comparator module the analog comparator module contains three compar- ators that can be independently configured in a variety of ways. the inputs can be selected from the analog inputs and two internal reference voltages. the digital outputs are available at the pin level and can also be read through the control register. multiple output and interrupt event generation are also available. a generic single comparator from the module is shown in figure 24-1 . key features of the module includes: independent comparator control programmable input configuration output to both pin and register levels programmable output polarity independent interrupt generation for each comparator with configurable interrupt-on-change 24.1 registers the cmxcon registers (cm1con, cm2con and cm3con) select the input and output configuration for each comparator, as well as the settings for interrupt generation (see register 24-1 ). the cmstat register ( register 24-2 ) provides the out- put results of the comparators. the bits in this register are read-only. figure 24-1: comparator simplified block diagram cx v in - v in + coe cxout 0 1 2 3 0 1 cch<1:0> cxinb cxinc (2) c2inb/c2ind (1,2) v bg cxina cv ref con interrupt logic evpol<1:0> cmpxout (cmstat<7:5>) cmpxif cpol polarity logic cref note 1: comparators, 1 and 3, use c2inb as an input to the inverting terminal. comparator 2 uses c2ind as an input to the inverted terminal. 2: c1inc, c2inc and c2ind are all unavailable for 64-pin devices (pic18f6xk22). downloaded from: http:///
pic18f87k22 family ds39960d-page 368 ? 2009-2011 microchip technology inc. register 24-1: cmxcon: comparator control x register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 con coe cpol evpol1 evpol0 cref cch1 cch0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 con: comparator enable bit 1 = comparator is enabled 0 = comparator is disabled bit 6 coe: comparator output enable bit 1 = comparator output is present on the cxout pin 0 = comparator output is internal only bit 5 cpol: comparator output polarity select bit 1 = comparator output is inverted 0 = comparator output is not inverted bit 4-3 evpol<1:0>: interrupt polarity select bits 11 = interrupt generation on any change of the output ( 1 ) 10 = interrupt generation only on high-to-low transition of the output 01 = interrupt generation only on low-to-high transition of the output 00 = interrupt generation is disabled bit 2 cref: comparator reference select bit (non-inverting input) 1 = non-inverting input connects to internal cv ref voltage 0 = non-inverting input connects to cxina pin bit 1-0 cch<1:0>: comparator channel select bits 11 = inverting input of comparator connects to v bg 10 = inverting input of comparator connects to c2inb or c2ind pin ( 2 , 3 ) 01 = inverting input of comparator connects to cxinc pin 00 = inverting input of comparator connects to cxinb pin note 1: the cmpxif bit is automatically set any time this mode is selected and must be cleared by the application after the initial configuration. 2: comparators, 1 and 3, use c2inb as an input to the inverting terminal. compar ator 2 uses c2ind. 3: c1inc, c2inc and c2ind are all unavailable for 64-pin devices (pic18f6xk22). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 369 pic18f87k22 family register 24-2: cmstat: comparator status register r-x r-x r-x u-0 u-0 u-0 u-0 u-0 cmp3out cmp2out cmp1out bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-5 cmp<3:1>out: comparator x status bits if cpol (cmxcon<5>)= 0 (non-inverted polarity): 1 = comparator xs v in + > v in - 0 = comparator xs v in + < v in - if cpol = 1 (inverted polarity): 1 = comparator xs v in + < v in - 0 = comparator xs v in + > v in - bit 4-0 unimplemented: read as 0 downloaded from: http:///
pic18f87k22 family ds39960d-page 370 ? 2009-2011 microchip technology inc. 24.2 comparator operation a single comparator is shown in figure 24-2 , along with the relationship between the analog input levels and the digital output. when the analog input at v in + is less than the analog input, v in -, the output of the compara- tor is a digital low level. when the analog input at v in + is greater than the analog input, v in -, the output of the comparator is a digital high level. the shaded areas of the output of the comparator, in figure 24-2 , represent the uncertainty due to input offsets and response time. figure 24-2: single comparator 24.3 comparator response time response time is the minimum time, after selecting a new reference voltage or input source, before the com- parator output has a valid level. the response time of the comparator differs from the settling time of the volt- age reference. therefore, both of these times must be considered when determining the total response to a comparator input change; otherwise, the maximum delay of the comparators should be used (see section 31.0 electrical characteristics ). 24.4 analog input connection considerations a simplified circuit for an analog input is shown in figure 24-3 . since the analog pins are connected to a digital output, they have reverse biased diodes to v dd and v ss . the analog input, therefore, must be between v ss and v dd . if the input voltage deviates from this range by more than 0.6v in either direction, one of the diodes is forward biased and a latch-up condition may occur. a maximum source impedance of 10 k ? is recommended for the analog sources. any external component connected to an analog input pin, such as a capacitor or a zener diode, should have very little leakage current. figure 24-3: comparator analog input model output v in - v in + C + v in + v in - output va r s a in c pin 5 pf v dd v t = 0.6v v t = 0.6v r ic i leakage 100 na v ss legend: c pin = input capacitance v t = threshold voltage i leakage = leakage current at the pin due to various junctions r ic = interconnect resistance r s = source impedance va = analog voltage comparator input <10k ? downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 371 pic18f87k22 family 24.5 comparator control and configuration each comparator has up to eight possible combina- tions of inputs: up to four external analog inputs and one of two internal reference voltages. all of the comparators allow a selection of the signal from pin, cxina, or the voltage from the comparator reference (cv ref ) on the non-inverting channel. this is compared to either cxinb, cxinc, c2inb/c2ind or the microcontrollers fixed internal reference voltage (v bg , 1.024v nominal) on the inverting channel. the comparator inputs and outputs are tied to fixed i/o pins, defined in table 24-1 . the available comparator config- urations and their corresponding bit settings are shown in figure 24-4 . table 24-1: comparator inputs and outputs 24.5.1 comparator enable and input selection setting the con bit of the cmxcon register (cmxcon<7>) enables the comparator for operation. clearing the con bit disables the comparator, resulting in minimum current consumption. the cch<1:0> bits in the cmxcon register (cmxcon<1:0>) direct either one of three analog input pins, or the internal reference voltage (vbg), to the comparator, v in -. depending on the comparator operating mode, either an external or internal refer- ence voltage may be used. for external analog pins that are unavailable in 64-pin devices (c1inc, c2inc and c2ind), the corresponding configurations that use them as inputs are unavailable. the analog signal present at v in - is compared to the signal at v in + and the digital output of the comparator is adjusted accordingly. the external reference is used when cref = 0 (cmxcon<2>) and v in + is connected to the cxina pin. when external reference voltages are used, the comparator module can be configured to have the reference sources externally. the reference signal must be between v ss and v dd , and can be applied to either pin of the comparator. the comparator module also allows the selection of an internally generated reference voltage from the com- parator voltage reference (cv ref ) module. this module is described in more detail in section 25.0 comparator voltage reference module . the reference from the comparator reference voltage module is only available when cref = 1 . in this mode, the internal reference voltage is applied to the comparators v in + pin. 24.5.2 comparator enable and output selection the comparator outputs are read through the cmstat register. the cmstat<5> bit reads the comparator 1 output, cmstat<6> reads comparator 2 output and cmstat<7> reads comparator 3 output. these bits are read-only. the comparator outputs may also be directly output to the rf2, rf1 and rg1 i/o pins by setting the coe bit (cmxcon<6>). when enabled, multiplexers in the output path of the pins switch to the output of the com- parator. while in this mode, the trisf<2:1> and trisg<1> bits still function as the digital output enable bits for the rf2, rf1 and rg1 pins. by default, the comparators output is at logic high whenever the voltage on v in + is greater than on v in -. the polarity of the comparator outputs can be inverted using the cpol bit (cmxcon<5>). the uncertainty of each of the comparators is related to the input offset voltage and the response time given in the specifications, as discussed in section 24.2 comparator operation . comparator input or output i/o pin 1 c1ina (v in +) rf6 c1inb (v in -) rf5 c1inc ( 1 ) (v in -) rh6 c2inb (v in -) rf3 c1out rf2 2 c2ina (v in +) rf4 c2inb (v in -) rf3 c2inc ( 1 ) (v in -) rh4 c2ind ( 1 ) (v in -) rh5 c2out rf1 3 c3ina (v in +) rg2 c3inb (v in -) rg3 c3inc (v in -) rg4 c2inb (v in -) rf3 c3out rg1 note 1: c1inc, c2inc and c2ind are all unavailable for 64-pin devices (pic18f6xk22). note: the comparator input pin, selected by cch<1:0>, must be configured as an input by setting both the corresponding trisf, trisg or trish bit and the corresponding anselx bit in the anconx register. downloaded from: http:///
pic18f87k22 family ds39960d-page 372 ? 2009-2011 microchip technology inc. figure 24-4: comparator configurations cx v in - v in + off (read as 0 ) comparator off con = 0 , cref = x , cch<1:0> = xx coe cx v in - v in + coe comparator cxinb > cxina compare con = 1 , cref = 0 , cch<1:0> = 00 cxinb cxina cx v in - v in + coe comparator cxinc > cxina compare (2,3) con = 1 , cref = 0 , cch<1:0> = 01 cxinc cxina cx v in - v in + coe comparator cxind > cxina compare (3) con = 1 , cref = 0 , cch<1:0> = 10 c2inb/ cxina cx v in - v in + coe comparator v irv > cxina compare con = 1 , cref = 0 , cch<1:0> = 11 v bg (1) cxina cx v in - v in + coe comparator cxinb > cv ref compare con = 1, cref = 1 , cch<1:0> = 00 cxinb cv ref cx v in - v in + coe comparator cxinc > cv ref compare (2,3) con = 1 , cref = 1 , cch<1:0> = 01 cxinc cv ref cx v in - v in + coe comparator cxind > cv ref compare (3) con = 1, cref = 1 , cch<1:0> = 10 cv ref cx v in - v in + coe pin comparator v irv > cv ref compare con = 1 , cref = 1 , cch<1:0> = 11 v bg (1) cv ref cxout note 1: vbg is the internal reference voltage (1.024v nominal). 2: configuration is unavailable for cm1c on on 64-pin devices (pic18f6xk22). 3: configuration is unavailable for cm2c on on 64-pin devices (pic18f6xk22). pin cxout pin cxout pin cxout pin cxout pin cxout pin cxout pin cxout pin cxout c2ind c2inb/ c2ind downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 373 pic18f87k22 family 24.6 comparator interrupts the comparator interrupt flag is set whenever any of the following occurs: low-to-high transition of the comparator output high-to-low transition of the comparator output any change in the comparator output the comparator interrupt selection is done by the evpol<1:0> bits in the cmxcon register (cmxcon<4:3>). in order to provide maximum flexibility, the output of the comparator may be inverted using the cpol bit in the cmxcon register (cmxcon<5>). this is functionally identical to reversing the inverting and non-inverting inputs of the comparator for a particular mode. an interrupt is generated on the low-to-high or high-to- low transition of the comparator output. this mode of interrupt generation is dependent on evpol<1:0> in the cmxcon register. when evpol<1:0> = 01 or 10 , the interrupt is generated on a low-to-high or high-to- low transition of the comparator output. once the interrupt is generated, it is required to clear the interrupt flag by software. when evpol<1:0> = 11 , the comparator interrupt flag is set whenever there is a change in the output value of either comparator. software will need to maintain information about the status of the output bits, as read from cmstat<7:5>, to determine the actual change that occurred. the cmpxif bits (pir6<2:0>) are the comparator interrupt flags. the cmpxif bits must be reset by clearing them. since it is also possible to write a 1 to this register, a simulated interrupt may be initiated. table 24-2 shows the interrupt generation with respect to comparator input voltages and evpol bit settings. both the cmpxie bits (pie6<2:0>) and the peie bit (intcon<6>) must be set to enable the interrupt. in addition, the gie bit (intcon<7>) must also be set. if any of these bits are clear, the interrupt is not enabled, though the cmpxif bits will still be set if an interrupt condition occurs. a simplified diagram of the interrupt section is shown in figure 24-3 . table 24-2: comparator interrupt generation note: the cmpxif bits will not be set when evpol<1:0> = 00 . cpol evpol<1:0> comparator input change cxout transition interrupt generated 0 00 v in + > v in - low-to-high no v in + < v in -h i g h - t o - l o w n o 01 v in + > v in - low-to-high yes v in + < v in -h i g h - t o - l o w n o 10 v in + > v in - low-to-high no v in + < v in -h i g h - t o - l o w y e s 11 v in + > v in - low-to-high yes v in + < v in -h i g h - t o - l o w y e s 1 00 v in + > v in -h i g h - t o - l o w n o v in + < v in - low-to-high no 01 v in + > v in -h i g h - t o - l o w n o v in + < v in - low-to-high yes 10 v in + > v in -h i g h - t o - l o w y e s v in + < v in - low-to-high no 11 v in + > v in -h i g h - t o - l o w y e s v in + < v in - low-to-high yes downloaded from: http:///
pic18f87k22 family ds39960d-page 374 ? 2009-2011 microchip technology inc. 24.7 comparator operation during sleep when a comparator is active and the device is placed in sleep mode, the comparator remains active and the interrupt is functional, if enabled. this interrupt will wake up the device from sleep mode, when enabled. each operational comparator will consume additional current. to minimize power consumption while in sleep mode, turn off the comparators (con = 0 ) before entering sleep. if the device wakes up from sleep, the contents of the cmxcon register are not affected. 24.8 effects of a reset a device reset forces the cmxcon registers to their reset state. this forces both comparators and the voltage reference to the off state. table 24-3: registers associated with comparator module name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir6 eeif cmp3if cmp2if cmp1if pie6 eeie cmp3ie cmp2ie cmp1ie ipr6 eeip cmp3ip cmp2ip cmp1ip cm1con con coe cpol evpol1 evpol0 cref cch1 cch0 cm2con con coe cpol evpol1 evpol0 cref cch1 cch0 cm3con con coe cpol evpol1 evpol0 cref cch1 cch0 cvrcon cvren cvroe cvrss cvr4 cvr3 cvr2 cvr1 cvr0 cmstat cmp3out cmp2out cmp1out portf rf7 rf6 rf5 rf4 rf3 rf2 rf1 latf latf7 latf6 latf5 latf4 latf3 latf2 latf1 trisf trisf7 trisf6 trisf5 trisf4 trisf3 trisf2 trisf1 portg rg5 ( 1 ) rg4 rg3 rg2 rg1 rg0 latg latg4 latg3 latg2 latg1 latg0 trisg trisg4 trisg3 trisg2 trisg1 trisg0 porth rh7 rh6 rh5 rh4 rh3 rh2 rh1 rh0 lath lath7 lath6 lath5 lath4 lath3 lath2 lath1 lath0 trish trish7 trish6 trish5 trish4 trish3 trish2 trish1 trish0 ancon0 ansel7 ansel6 ansel5 ansel4 ansel3 ansel2 ansel1 ansel0 ancon1 ansel15 ansel14 ansel13 ansel 12 ansel11 ansel10 ansel9 ansel8 ancon2 ansel23 ansel22 ansel21 ansel20 ansel19 ansel18 ansel17 ansel16 pmd0 ccp3md ccp2md ccp1md uart2md uart1md ssp2md ssp1md adcmd legend: = unimplemented, read as 0 . note 1: bit is available when master clear is disabled (mclre = 0 ). when mclre is set, the bit is unimplemented. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 375 pic18f87k22 family 25.0 comparator voltage reference module the comparator voltage reference is a 32-tap resistor ladder network that provides a selectable reference voltage. although its primary purpose is to provide a reference for the analog comparators, it may also be used independently of them. a block diagram of the module is shown in figure 25-1 . the resistor ladder is segmented to provide a range of cv ref values and has a power-down function to conserve power when the reference is not being used. the modules supply reference can be provided from either device v dd /v ss or an external voltage reference. 25.1 configuring the comparator voltage reference the comparator voltage reference module is controlled through the cvrcon register ( register 25-1 ). the comparator voltage reference provides a range of output voltage with 32 levels. the cvr<4:0> selection bits (cvrcon<4:0>) offer a range of output voltages. equation 25-1 shows the how the comparator voltage reference is computed. equation 25-1: the comparator reference supply voltage can come from either v dd and v ss , or the external v ref + and v ref - that are multiplexed with ra3 and ra2. the voltage source is selected by the cvrss bit (cvrcon<5>). the settling time of the comparator voltage reference must be considered when changing the cv ref output (see table 31-2 in section 31.0 electrical characteristics ). c vref = (v ref -) + (cvr<4:0>/32) (v ref + C v ref -) if cvrss = 1 : c vref = (av ss ) + (cvr<4:0>/32) (av dd C av ss ) if cvrss = 0 : register 25-1: cvrcon: comparator vo ltage reference control register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 cvren cvroe cvrss cvr4 cvr3 cvr2 cvr1 cvr0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 cvren: comparator voltage reference enable bit 1 =cv ref circuit is powered on 0 =cv ref circuit is powered down bit 6 cvroe: comparator v ref output enable bit 1 =cv ref voltage level is output on cv ref pin 0 =cv ref voltage level is disconnected from cv ref pin bit 5 cvrss: comparator v ref source selection bit 1 = comparator reference source, cv rsrc = v ref +Cv ref - 0 = comparator reference source, cv rsrc = av dd Cav ss bit 4-0 cvr<4:0>: comparator v ref value selection 0 ? cvr<4:0> ? 31 bits when cvrss = 1 : cv ref = (v ref -) + (cvr<4:0>/32) ? (v ref + C v ref -) when cvrss = 0 : cv ref = (av ss ) + (cvr<4:0>/32) ? (av dd C av ss ) downloaded from: http:///
pic18f87k22 family ds39960d-page 376 ? 2009-2011 microchip technology inc. figure 25-1: comparator voltage reference block diagram 25.2 voltage reference accuracy/error the full range of voltage reference cannot be realized due to the construction of the module. the transistors on the top and bottom of the resistor ladder network ( figure 25-1 ) keep cv ref from approaching the refer- ence source rails. the voltage reference is derived from the reference source; therefore, the cv ref output changes with fluctuations in that source. the tested absolute accuracy of the voltage reference can be found in section 31.0 electrical characteristics . 25.3 operation during sleep when the device wakes up from sleep through an interrupt or a watchdog timer time-out, the contents of the cvrcon register are not affected. to minimize current consumption in sleep mode, the voltage reference should be disabled. 25.4 effects of a reset a device reset disables the voltage reference by clearing bit, cvren (cvrcon<7>). this reset also disconnects the reference from the rf5 pin by clearing bit, cvroe (cvrcon<6>). 25.5 connection considerations the voltage reference module operates independently of the comparator module. the output of the reference generator may be connected to the rf5 pin if the cvroe bit is set. enabling the voltage reference out- put onto rf5 when it is configured as a digital input will increase current consumption. connecting rf5 as a digital output, with cvrss enabled, will also increase current consumption. the rf5 pin can be used as a simple d/a output with limited drive capability. due to the limited current drive capability, a buffer must be used on the voltage reference output for external connections to v ref . figure 25-2 shows an example buffering technique. 32-to-1 mux cvr<4:0> r cvren cvrss = 0 av dd v ref + cvrss = 1 rr r r r r 32 steps cv ref v ref - cvrss = 1 cvrss = 0 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 377 pic18f87k22 family figure 25-2: comparator voltage refere nce output buffer example table 25-1: registers associated with comparator voltage reference name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 cvrcon cvren cvroe cvrss cvr4 cvr3 cvr2 cvr1 cvr0 cm1con con coe cpol evpol1 evpol0 cref cch1 cch0 cm2con con coe cpol evpol1 evpol0 cref cch1 cch0 cm3con con coe cpol evpol1 evpol0 cref cch1 cch0 trisf trisf7 trisf6 trisf5 trisf4 trisf3 trisf2 trisf1 trisa trisa7 trisa6 trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 ancon0 ansel7 ansel6 ansel5 ansel4 ansel3 ansel2 ansel1 ansel0 ancon1 ansel15 ansel14 ansel13 ansel12 ansel11 ansel10 ansel9 ansel8 legend: = unimplemented, read as 0 . shaded cells are not used with the comparator voltage reference. cv ref output +C cv ref module voltage reference output impedance r (1) pic18f87k22 note 1: r is dependent upon the voltage reference configuration bits, cvrcon<3:0> and cvrcon<5>. rf5 downloaded from: http:///
pic18f87k22 family ds39960d-page 378 ? 2009-2011 microchip technology inc. notes: downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 379 pic18f87k22 family 26.0 high/low-voltage detect (hlvd) the pic18f87k22 family of devices has a high/low- voltage detect module (hlvd). this is a programmable circuit that sets both a device voltage trip point and the direction of change from that point. if the device experi- ences an excursion past the trip point in that direction, an interrupt flag is set. if the interrupt is enabled, the pro- gram execution branches to the interrupt vector address and the software responds to the interrupt. the high/low-voltage detect control register ( register 26-1 ) completely controls the operation of the hlvd module. this allows the circuitry to be turned off by the user under software control, which minimizes the current consumption for the device. the modules block diagram is shown in figure 26-1 . register 26-1: hlvdcon: high/low-v oltage detect control register r/w-0 r-0 r-0 r/w-0 r/w-0 r/w-1 r/w-0 r/w-0 vdirmag bgvst irvst hlvden hlvdl3 ( 1 ) hlvdl2 ( 1 ) hlvdl1 ( 1 ) hlvdl0 ( 1 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 vdirmag: voltage direction magnitude select bit 1 = event occurs when voltage equals or exceeds trip point (hlvdl<3:0>) 0 = event occurs when voltage equals or falls below trip point (hlvdl<3:0>) bit 6 bgvst: band gap reference voltages stable status flag bit 1 = internal band gap voltage references are stable 0 = internal band gap voltage references are not stable bit 5 irvst: internal reference voltage stable flag bit 1 = indicates that the voltage detect logic will generate the interrupt flag at the specified voltage range 0 = indicates that the voltage detect logic will not generate the interrupt flag at the specified voltage range and the hlvd interrupt should not be enabled bit 4 hlvden: high/low-voltage detect power enable bit 1 = hlvd is enabled 0 = hlvd is disabled bit 3-0 hlvdl<3:0>: voltage detection limit bits ( 1 ) 1111 = external analog input is used (input comes from the hlvdin pin) 1110 = maximum setting .. . 0000 = minimum setting note 1: for the electrical specifications, see parameter d420. downloaded from: http:///
pic18f87k22 family ds39960d-page 380 ? 2009-2011 microchip technology inc. the module is enabled by setting the hlvden bit (hlvdcon<4>). each time the hlvd module is enabled, the circuitry requires some time to stabilize. the irvst bit (hlvdcon<5>) is a read-only bit used to indicate when the circuit is stable. the module can only generate an interrupt after the circuit is stable and irvst is set. the vdirmag bit (hlvdcon<7>) determines the overall operation of the module. when vdirmag is cleared, the module monitors for drops in v dd below a predetermined set point. when the bit is set, the module monitors for rises in v dd above the set point. 26.1 operation when the hlvd module is enabled, a comparator uses an internally generated voltage reference as the set point. the set point is compared with the trip point, where each node in the resistor divider represents a trip point voltage. the trip point voltage is the voltage level at which the device detects a high or low-voltage event, depending on the configuration of the module. when the supply voltage is equal to the trip point, the voltage tapped off of the resistor array is equal to the internal reference voltage generated by the voltage reference module. the comparator then generates an interrupt signal by setting the hlvdif bit. the trip point voltage is software programmable to any of 16 values. the trip point is selected by programming the hlvdl<3:0> bits (hlvdcon<3:0>). the hlvd module has an additional feature that allows the user to supply the trip voltage to the module from an external source. this mode is enabled when bits, hlvdl<3:0>, are set to 1111 . in this state, the comparator input is multiplexed from the external input pin, hlvdin. this gives users the flexibility of configur- ing the high/low-voltage detect interrupt to occur at any voltage in the valid operating range. figure 26-1: hlvd mo dule block diagram (with external input) set v dd 16-to-1 mux hlvden hlvdcon hlvdl<3:0> register hlvdin v dd externally generated trip point hlvdif hlvden boren internal voltage reference vdirmag 1.024v typical downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 381 pic18f87k22 family 26.2 hlvd setup to set up the hlvd module: 1. select the desired hlvd trip point by writing the value to the hlvdl<3:0> bits. 2. set the vdirmag bit to detect high voltage (vdirmag = 1 ) or low voltage (vdirmag = 0 ). 3. enable the hlvd module by setting the hlvden bit. 4. clear the hlvd interrupt flag (pir2<2>), which may have been set from a previous interrupt. 5. if interrupts are desired, enable the hlvd inter- rupt by setting the hlvdie and gie bits (pie2<2> and intcon<7>, respectively). an interrupt will not be generated until the irvst bit is set. 26.3 current consumption when the module is enabled, the hlvd comparator and voltage divider are enabled and consume static current. the total current consumption, when enabled, is specified in electrical specification parameter d022b ( table 31-13 ). depending on the application, the hlvd module does not need to operate constantly. to reduce current requirements, the hlvd circuitry may only need to be enabled for short periods where the voltage is checked. after such a check, the module could be disabled. 26.4 hlvd start-up time the internal reference voltage of the hlvd module, specified in electrical specification parameter 37 ( section 31.0 electrical characteristics ), may be used by other internal circuitry, such as the programmable brown-out reset. if the hlvd or other circuits using the voltage reference are disabled to lower the devices current consumption, the reference voltage circuit will require time to become stable before a low or high-voltage condition can be reliably detected. this start-up time, t irvst , is an interval that is independent of device clock speed. it is specified in electrical specification parameter 37 ( table 31-13 ). the hlvd interrupt flag is not enabled until t irvst has expired and a stable reference voltage is reached. for this reason, brief excursions beyond the set point may not be detected during this interval (see figure 26-2 or figure 26-3 ). note: before changing any module settings (v dirmag , lvdl<3:0>), first disable the module (lvden = 0 ), make the changes and re-enable the module. this prevents the generation of false hlvd events. downloaded from: http:///
pic18f87k22 family ds39960d-page 382 ? 2009-2011 microchip technology inc. figure 26-2: low-voltage detect operation (vdirmag = 0 ) v hlvd v dd hlvdif v hlvd v dd enable hlvd t irvst hlvdif may not be set enable hlvd hlvdif hlvdif cleared in software hlvdif cleared in software hlvdif cleared in software, case 1: case 2: hlvdif remains set since hlvd condition still exists t irvst internal reference is stable internal reference is stable irvst irvst downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 383 pic18f87k22 family figure 26-3: high-voltage detect operation (vdirmag = 1 ) 26.5 applications in many applications, it is desirable to detect a drop below, or rise above, a particular voltage threshold. for example, the hlvd module could be periodically enabled to detect universal serial bus (usb) attach or detach. this assumes the device is powered by a lower voltage source than the usb when detached. an attach would indicate a high-voltage detect from, for example, 3.3v to 5v (the voltage on usb) and vice versa for a detach. this feature could save a design a few extra components and an attach signal (input pin). for general battery applications, figure 26-4 shows a possible voltage curve. over time, the device voltage decreases. when the device voltage reaches voltage, v a , the hlvd logic generates an interrupt at time, t a . the interrupt could cause the execution of an interrupt service routine (isr), which would allow the applica- tion to perform housekeeping tasks and a controlled shutdown before the device voltage exits the valid operating range at t b . this would give the application a time window, represented by the difference between t a and t b , to safely exit. figure 26-4: typical low-voltage detect application v hlvd v dd hlvdif v hlvd v dd enable hlvd t irvst hlvdif may not be set enable hlvd hlvdif hlvdif cleared in software hlvdif cleared in software hlvdif cleared in software, case 1: case 2: hlvdif remains set since hlvd condition still exists t irvst irvst internal reference is stable internal reference is stable irvst time voltage v a v b t a t b v a = hlvd trip point v b = minimum valid device operating voltage legend: downloaded from: http:///
pic18f87k22 family ds39960d-page 384 ? 2009-2011 microchip technology inc. 26.6 operation during sleep when enabled, the hlvd circuitry continues to operate during sleep. if the device voltage crosses the trip point, the hlvdif bit will be set and the device will wake up from sleep. device execution will continue from the interrupt vector address if interrupts have been globally enabled. 26.7 effects of a reset a device reset forces all registers to their reset state. this forces the hlvd module to be turned off. table 26-1: registers associated wi th high/low-voltage detect module name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 hlvdcon vdirmag bgvst irvst hlvden hlvdl3 hlvdl2 hlvdl1 hlvdl0 intcon gie/gieh peie/giel tmr0ie int0ie rbie tmr0if int0if rbif pir2 oscfif ssp2if blc2if bcl1if hlvdif tmr3if tmr3gif pie2 oscfie ssp2ie blc2ie bcl1ie hlvdie tmr3ie tmr3gie ipr2 oscfip ssp2ip blc2ip bcl1ip hlvdip tmr3ip tmr3gip trisa trisa7 ( 1 ) trisa6 ( 1 ) trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 ancon0 ansel7 ansel6 ansel5 ansel4 ansel3 ansel2 ansel1 ansel0 legend: = unimplemented, read as 0 . shaded cells are unused by the hlvd module. note 1: porta<7:6> and their direction bits are individually configured as port pins based on various primary oscillator modes. when disabled, these bits read as 0 . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 385 pic18f87k22 family 27.0 charge time measurement unit (ctmu) the charge time measurement unit (ctmu) is a flexible analog module that provides accurate differen- tial time measurement between pulse sources, as well as asynchronous pulse generation. by working with other on-chip analog modules, the ctmu can precisely measure time, capacitance and relative changes in capacitance or generate output pulses with a specific time delay. the ctmu is ideal for interfacing with capacitive-based sensors. the module includes these key features: up to 24 channels available for capacitive or time measurement input on-chip precision current source four-edge input trigger sources polarity control for each edge source control of edge sequence control of response to edges time measurement resolution of 1 nanosecond high-precision time measurement time delay of external or internal signal asynchronous to system clock accurate current source suitable for capacitive measurement the ctmu works in conjunction with the a/d converter to provide up to 24 channels for time or charge measurement, depending on the specific device and the number of a/d channels available. when config- ured for time delay, the ctmu is connected to one of the analog comparators. the level-sensitive input edge sources can be selected from four sources: two external inputs or the eccp1/eccp2 special event triggers. the ctmu special event can trigger the analog-to-digital converter module. figure 27-1 provides a block diagram of the ctmu. figure 27-1: ctmu block diagram cted1 cted2 current source edge control logic ctmucon pulse generator a/d converter comparator 2 input eccp2 eccp1 current control itrim<5:0> irng<1:0> ctmuicon ctmu control logic edgen edgseqen edg1selx edg1pol edg2selx edg2pol edg1stat edg2stat tgen idissen cttrig a/d trigger ctpls comparator 2 output downloaded from: http:///
pic18f87k22 family ds39960d-page 386 ? 2009-2011 microchip technology inc. 27.1 ctmu registers the control registers for the ctmu are: ctmuconh ctmuconl ctmuicon the ctmuconh and ctmuconl registers ( register 27-1 and register 27-2 ) contain control bits for configuring the ctmu module edge source selec- tion, edge source polarity selection, edge sequencing, a/d trigger, analog circuit capacitor discharge and enables. the ctmuicon register ( register 27-3 ) has bits for selecting the current source range and current source trim. register 27-1: ctmuconh: ct mu control high register r/w-0 u-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 ctmuen ctmusidl tgen edgen edgseqen idissen cttrig bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 ctmuen: ctmu enable bit 1 = module is enabled 0 = module is disabled bit 6 unimplemented: read as 0 bit 5 ctmusidl: stop in idle mode bit 1 = discontinue module operation when device enters idle mode 0 = continue module operation in idle mode bit 4 tgen: time generation enable bit 1 = enables edge delay generation 0 = disables edge delay generation bit 3 edgen: edge enable bit 1 = edges are not blocked 0 = edges are blocked bit 2 edgseqen: edge sequence enable bit 1 = edge 1 event must occur before edge 2 event can occur 0 = no edge sequence is needed bit 1 idissen: analog current source control bit 1 = analog current source output is grounded 0 = analog current source output is not grounded bit 0 cttrig: trigger control bit 1 = trigger output is enabled 0 = trigger output is disabled downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 387 pic18f87k22 family register 27-2: ctmuconl: ct mu control low register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 edg2pol edg2sel1 edg2sel0 edg1pol ed g1sel1 edg1sel0 edg2stat edg1stat bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 edg2pol: edge 2 polarity select bit 1 = edge 2 is programmed for a positive edge response 0 = edge 2 is programmed for a negative edge response bit 6-5 edg2sel<1:0>: edge 2 source select bits 11 = cted1 pin 10 = cted2 pin 01 = eccp1 special event trigger 00 = eccp2 special event trigger bit 4 edg1pol: edge 1 polarity select bit 1 = edge 1 is programmed for a positive edge response 0 = edge 1 is programmed for a negative edge response bit 3-2 edg1sel<1:0>: edge 1 source select bits 11 = cted1 pin 10 = cted2 pin 01 = eccp1 special event trigger 00 = eccp2 special event trigger bit 1 edg2stat: edge 2 status bit 1 = edge 2 event has occurred 0 = edge 2 event has not occurred bit 0 edg1stat: edge 1 status bit 1 = edge 1 event has occurred 0 = edge 1 event has not occurred downloaded from: http:///
pic18f87k22 family ds39960d-page 388 ? 2009-2011 microchip technology inc. register 27-3: ctmuicon: ctmu current control register r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 r/w-0 itrim5 itrim4 itrim3 itrim2 itrim1 itrim0 irng1 irng0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-2 itrim<5:0>: current source trim bits 011111 = maximum positive change from nominal current 011110 . . . 000001 = minimum positive change from nominal current 000000 = nominal current output specified by irng<1:0> 111111 = minimum negative change from nominal current .. . 100010 100001 = maximum negative change from nominal current bit 1-0 irng<1:0>: current source range select bits 11 = 100 x base current 10 = 10 x base current 01 = base current level (0.55 ? a nominal) 00 = current source disabled downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 389 pic18f87k22 family 27.2 ctmu operation the ctmu works by using a fixed current source to charge a circuit. the type of circuit depends on the type of measurement being made. in the case of charge measurement, the current is fixed and the amount of time the current is applied to the cir- cuit is fixed. the amount of voltage read by the a/d becomes a measurement of the circuits capacitance. in the case of time measurement, the current, as well as the capacitance of the circuit, is fixed. in this case, the voltage read by the a/d is representative of the amount of time elapsed from the time the current source starts and stops charging the circuit. if the ctmu is being used as a time delay, both capaci- tance and current source are fixed, as well as the voltage supplied to the comparator circuit. the delay of a signal is determined by the amount of time it takes the voltage to charge to the comparator threshold voltage. 27.2.1 theory of operation the operation of the ctmu is based on the equation for charge: more simply, the amount of charge measured in coulombs in a circuit is defined as current in amperes ( i ) multiplied by the amount of time in seconds that the current flows ( t ). charge is also defined as the capaci- tance in farads ( c ) multiplied by the voltage of the circuit ( v ). it follows that: the ctmu module provides a constant, known current source. the a/d converter is used to measure ( v ) in the equation, leaving two unknowns: capacitance ( c ) and time ( t ). the above equation can be used to calcu- late capacitance or time, by either the relationship using the known fixed capacitance of the circuit: or by: using a fixed time that the current source is applied to the circuit. 27.2.2 current source at the heart of the ctmu is a precision current source, designed to provide a constant reference for measure- ments. the level of current is user-selectable across three ranges or a total of two orders of magnitude, with the ability to trim the output in 2% increments (nominal). the current range is selected by the irng<1:0> bits (ctmuicon<1:0>), with a value of 00 representing the lowest range. current trim is provided by the itrim<5:0> bits (ctmuicon<7:2>). these six bits allow trimming of the current source in steps of approximately 2% per step. half of the range adjusts the current source posi- tively and the other half reduces the current source. a value of 000000 is the neutral position (no change). a value of 100000 is the maximum negative adjustment (approximately -62%) and 011111 is the maximum positive adjustment (approximately +62%). 27.2.3 edge selection and control ctmu measurements are controlled by edge events occurring on the modules two input channels. each channel, referred to as edge 1 and edge 2, can be con- figured to receive input pulses from one of the edge input pins (cted1 and cted2) or ccpx special event triggers. the input channels are level-sensitive, responding to the instantaneous level on the channel rather than a transition between levels. the inputs are selected using the edg1sel and edg2sel bit pairs (ctmuconl<3:2, 6:5>). in addition to source, each channel can be configured for event polarity using the edge2pol and edge1pol bits (ctmuconl<7,4>). the input channels can also be filtered for an edge event sequence (edge 1 occur- ring before edge 2) by setting the edgseqen bit (ctmuconh<2>). 27.2.4 edge status the ctmucon register also contains two status bits: edg2stat and edg1stat (ctmuconl<1:0>). their primary function is to show if an edge response has occurred on the corresponding channel. the ctmu automatically sets a particular bit when an edge response is detected on its channel. the level-sensitive nature of the input channels also means that the status bits become set immediately if the channels configura- tion is changed and matches the channels current state. the module uses the edge status bits to control the cur- rent source output to external analog modules (such as the a/d converter). current is only supplied to external modules when only one (not both) of the status bits is set. current is shut off when both bits are either set or cleared. this allows the ctmu to measure current only during the interval between edges. after both status bits are set, it is necessary to clear them before another measurement is taken. both bits should be cleared simultaneously, if possible, to avoid re-enabling the ctmu current source. in addition to being set by the ctmu hardware, the edge status bits can also be set by software. this per- mits a user application to manually enable or disable the current source. setting either (but not both) of the bits enables the current source. setting or clearing both bits at once disables the source. c = i dv dt i t = c v t = (c v)/i c = (i t)/v downloaded from: http:///
pic18f87k22 family ds39960d-page 390 ? 2009-2011 microchip technology inc. 27.2.5 interrupts the ctmu sets its interrupt flag (pir3<3>) whenever the current source is enabled, then disabled. an inter- rupt is generated only if the corresponding interrupt enable bit (pie3<3>) is also set. if edge sequencing is not enabled (i.e., edge 1 must occur before edge 2), it is necessary to monitor the edge status bits and determine which edge occurred last and caused the interrupt. 27.3 ctmu module initialization the following sequence is a general guideline used to initialize the ctmu module: 1. select the current source range using the irngx bits (ctmuicon<1:0>). 2. adjust the current source trim using the itrimx bits (ctmuicon<7:2>). 3. configure the edge input sources for edge 1 and edge 2 by setting the edg1sel and edg2sel bits (ctmuconl<3:2> and <6:5>, respectively). 4. configure the input polarities for the edge inputs using the edg2pol and edg1pol bits (ctmuconl<7,4>). the default configuration is for negative edge polarity (high-to-low transitions). 5. enable edge sequencing using the edgseqen bit (ctmuconh<2>). by default, edge sequencing is disabled. 6. select the operating mode (measurement or time delay) with the tgen bit. the default mode is time/capacitance measurement. 7. configure the module to automatically trigger an a/d conversion when the second edge event has occurred, using the cttrig bit (ctmuconh<0>). the conversion trigger is disabled by default. 8. discharge the connected circuit by setting the idissen bit (ctmuconh<1>). 9. after waiting a sufficient time for the circuit to discharge, clear idissen. 10. disable the module by clearing the ctmuen bit (ctmuconh<7>). 11. clear the edge status bits, edg2stat and edg1stat (ctmuconl<1:0>). 12. enable both edge inputs by setting the edgen bit (ctmuconh<3>). 13. enable the module by setting the ctmuen bit. depending on the type of measurement or pulse generation being performed, one or more additional modules may also need to be initialized and configured with the ctmu module: edge source generation: in addition to the external edge input pins, ccpx special event triggers can be used as edge sources for the ctmu. capacitance or time measurement: the ctmu module uses the a/d converter to measure the voltage across a capacitor that is connected to one of the analog input channels. pulse generation: when generating system clock independent, output pulses, the ctmu module uses comparator 2 and the associated comparator voltage reference. 27.4 calibrating the ctmu module the ctmu requires calibration for precise measure- ments of capacitance and time, as well as for accurate time delay. if the application only requires measurement of a relative change in capacitance or time, calibration is usually not necessary. an example of a less precise application is a capacitive touch switch, in which the touch circuit has a baseline capacitance and the added capacitance of the human body changes the overall capacitance of a circuit. if actual capacitance or time measurement is required, two hardware calibrations must take place: the current source needs calibration to set it to a precise current. the circuit being measured needs calibration to measure or nullify any capacitance other than that to be measured. 27.4.1 current source calibration the current source on board the ctmu module has a range of 60% nominal for each of three current ranges. for precise measurements, it is possible to measure and adjust this current source by placing a high-precision resistor, r cal , onto an unused analog channel. an example circuit is shown in figure 27-2 . to measure the current source: 1. initialize the a/d converter. 2. initialize the ctmu. 3. enable the current source by setting edg1stat (ctmuconl<0>). 4. issue the settling time delay. 5. perform the a/d conversion. 6. calculate the current source current using i=v/r cal , where r cal is a high-precision resistance and v is measured by performing an a/d conversion. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 391 pic18f87k22 family the ctmu current source may be trimmed with the trim bits in ctmuicon using an iterative process to get the exact current desired. alternatively, the nominal value without adjustment may be used. that value may be stored by software for use in all subsequent capacitive or time measurements. to calculate the value for r cal , the nominal current must be chosen. then, the resistance can be calculated. for example, if the a/d converter reference voltage is 3.3v, use 70% of full scale (or 2.31v) as the desired approximate voltage to be read by the a/d converter. if the range of the ctmu current source is selected to be 0.55 ? a, the resistor value needed is calculated as r cal = 2.31v/0.55 ? a , for a value of 4.2 m ? . similarly, if the current source is chosen to be 5.5 ? a, r cal would be 420,000 ? , and 42,000 ? if the current source is set to 55 ? a. figure 27-2: ctmu current source calibration circuit a value of 70% of full-scale voltage is chosen to make sure that the a/d converter was in a range that is well above the noise floor. if an exact current is chosen to incorporate the trimming bits from ctmuicon, the resistor value of r cal may need to be adjusted accord- ingly. r cal may also be adjusted to allow for available resistor values. r cal should be of the highest precision available, in light of the precision needed for the circuit that the ctmu will be measuring. a recommended minimum would be 0.1% tolerance. the following examples show a typical method for performing a ctmu current calibration. example 27-1 demonstrates how to initialize the a/d converter and the ctmu. this routine is typical for applications using both modules. example 27-2 demonstrates one method for the actual calibration routine. this method manually triggers the a/d converter to demonstrate the entire step-wise process. it is also possible to automatically trigger the conversion by setting the ctmus cttrig bit (ctmuconh<0>). a/d converter ctmu anx r cal current source a/d trigger mux a/d pic18f87k22 downloaded from: http:///
pic18f87k22 family ds39960d-page 392 ? 2009-2011 microchip technology inc. example 27-1: setup for ct mu calibration routines #include "p18cxxx.h" /**************************************************************************/ /*setup ctmu *****************************************************************/ /**************************************************************************/ void setup(void) { //ctmucon - ctmu control register ctmuconh = 0x00; //make sure ctmu is disabled ctmuconl = 0x90; //ctmu continues to run when emulator is stopped,ctmu continues //to run in idle mode,time generation mode disabled, edges are blocked //no edge sequence order, analog current source not grounded, trigger //output disabled, edge2 polarity = positive level, edge2 source = //source 0, edge1 polarity = positive level, edge1 source = source 0, // set edge status bits to zero //ctmuicon - ctmu current control register ctmuicon = 0x01; //0.55ua, nominal - no adjustment /**************************************************************************/ //setup ad converter; /**************************************************************************/ trisa=0x04; //set channel 2 as an input // configured an2 as an analog channel // ancon0 ancon0 = 0x04; // ancon1 ancon1 = 0xe0; // adcon2 adcon2bits.adfm=1; // resulst format 1= right justified adcon2bits.acqt=1; // acquition time 7 = 20tad 2 = 4tad 1=2tad adcon2bits.adcs=2; // clock conversion bits 6= fosc/64 2=fosc/32 // adcon0 adcon1bits.vcfg0 =0; // vref+ = avdd adcon0bits.vcfg1 =0; // vref+ = avdd adcon0bits.vcfg = 0; // vref- = avss adcon0bits.chs=2; // select adc channel adcon0bits.adon=1; // turn on adc } downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 393 pic18f87k22 family example 27-2: current calibration routine #include "p18cxxx.h" #define count 500 //@ 8mhz = 125us. #define delay for(i=0;i pic18f87k22 family ds39960d-page 394 ? 2009-2011 microchip technology inc. 27.4.2 capacitance calibration there is a small amount of capacitance from the inter- nal a/d converter sample capacitor, as well as stray capacitance from the circuit board traces and pads that affect the precision of capacitance measurements. a measurement of the stray capacitance can be taken by making sure the desired capacitance to be measured has been removed. after removing the capacitance to be measured: 1. initialize the a/d converter and the ctmu. 2. set edg1stat (= 1 ). 3. wait for a fixed delay of time, t . 4. clear edg1stat. 5. perform an a/d conversion. 6. calculate the stray and a/d sample capacitances: where: i is known from the current source measurement step t is a fixed delay v is measured by performing an a/d conversion this measured value is then stored and used for calculations of time measurement or subtracted for capacitance measurement. for calibration, it is expected that the capacitance of c stray + c ad is approximately known; c ad is approximately 4 pf. an iterative process may be required to adjust the time, t , that the circuit is charged to obtain a reasonable volt- age reading from the a/d converter. the value of t may be determined by setting c offset to a theoretical value and solving for t . for example, if c stray is theoretically calculated to be 11 pf, and v is expected to be 70% of v dd or 2.31v, t would be: or 63 ? s. see example 27-3 for a typical routine for ctmu capacitance calibration. c offset = c stray + c ad = (i t)/v (4 pf + 11 pf) 2.31v/0.55 ? a downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 395 pic18f87k22 family example 27-3: capacitance calibration routine #include "p18cxxx.h" #define count 25 //@ 8mhz intfrc = 62.5 us. #define etime count*2.5 //time in us #define delay for(i=0;i pic18f87k22 family ds39960d-page 396 ? 2009-2011 microchip technology inc. 27.5 measuring capacitance with the ctmu there are two ways to measure capacitance with the ctmu. the absolute method measures the actual capacitance value. the relative method only measures for any change in the capacitance. 27.5.1 absolute capacitance measurement for absolute capacitance measurements, both the current and capacitance calibration steps found in section 27.4 calibrating the ctmu module should be followed. to perform these measurements: 1. initialize the a/d converter. 2. initialize the ctmu. 3. set edg1stat. 4. wait for a fixed delay, t . 5. clear edg1stat. 6. perform an a/d conversion. 7. calculate the total capacitance, c total = (i * t)/v , where: i is known from the current source measurement step ( section 27.4.1 current source calibration ) t is a fixed delay v is measured by performing an a/d conversion 8. subtract the stray and a/d capacitance ( c offset from section 27.4.2 capacitance calibration ) from c total to determine the measured capacitance. 27.5.2 relative charge measurement not all applications require precise capacitance measurements. when detecting a valid press of a capacitance-based switch, only a relative change of capacitance needs to be detected. in such an application, when the switch is open (or not touched), the total capacitance is the capacitance of the combination of the board traces, the a/d converter and other elements. a larger voltage will be measured by the a/d converter. when the switch is closed (or touched), the total capacitance is larger due to the addition of the capacitance of the human body to the above listed capacitances and a smaller voltage will be measured by the a/d converter. to detect capacitance changes simply: 1. initialize the a/d converter and the ctmu. 2. set edg1stat. 3. wait for a fixed delay. 4. clear edg1stat. 5. perform an a/d conversion. the voltage measured by performing the a/d conver- sion is an indication of the relative capacitance. in this case, no calibration of the current source or circuit capacitance measurement is needed. (for a sample software routine for a capacitive touch switch, see example 27-4 .) downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 397 pic18f87k22 family example 27-4: routine fo r capacitive touch switch #include "p18cxxx.h" #define count 500 //@ 8mhz = 125us. #define delay for(i=0;i opensw - trip + hyst) { switchstate = unpressed; } } downloaded from: http:///
pic18f87k22 family ds39960d-page 398 ? 2009-2011 microchip technology inc. 27.6 measuring time with the ctmu module time can be precisely measured after the ratio ( c/i ) is measured from the current and capacitance calibration step. to do that: 1. initialize the a/d converter and the ctmu. 2. set edg1stat. 3. set edg2stat. 4. perform an a/d conversion. 5. calculate the time between edges as t = (c/i) * v , where: i is calculated in the current calibration step ( section 27.4.1 current source calibration ) c is calculated in the capacitance calibra- tion step ( section 27.4.2 capacitance calibration ) v is measured by performing the a/d conversion it is assumed that the time measured is small enough that the capacitance, c offset , provides a valid voltage to the a/d converter. for the smallest time measure- ment, always set the a/d channel select register (ad1chs) to an unused a/d channel, the correspond- ing pin for which is not connected to any circuit board trace. this minimizes added stray capacitance, keep- ing the total circuit capacitance close to that of the a/d converter itself (25 pf). to measure longer time intervals, an external capacitor may be connected to an a/d channel and that channel selected whenever making a time measurement. figure 27-3: typical co nnections and internal configuration for time measurement a/d converter ctmu cted1 cted2 an x output pulse edg1 edg2 c ad r pr current source pic18f87k22 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 399 pic18f87k22 family 27.7 creating a delay with the ctmu module a unique feature on board the ctmu module is its ability to generate system clock independent output pulses, based on either an external voltage or an external capacitor value. when using an external voltage, this is accomplished using the ctdin input pin as a trigger for the pulse delay. when using an external capacitor value, this is accomplished using the internal compara- tor voltage reference module and comparator 2 input pin.the pulse is output onto the ctpls pin. to enable this mode, set the tgen bit. see figure 27-4 for an example circuit. when ctmuds (odcon3<0>) is cleared, the pulse delay is determined by the output of comparator 2, and when it is set, the pulse delay is determined by the input of ctdin. c delay is chosen by the user to determine the output pulse width on ctpls. the pulse width is calcu- lated by t = (c delay /i) * v , where i is known from the current source measurement step ( section 27.4.1 current source calibration ) and v is the internal reference voltage (cv ref ). an example use of the external capacitor feature is interfacing with variable capacitive-based sensors, such as a humidity sensor. as the humidity varies, the pulse-width output on ctpls will vary. an example use of the ctdin feature is interfacing with a digital sensor. the ctpls output pin can be connected to an input capture pin and the varying pulse width measured to determine the sensors output in the application. to use this feature: 1. if ctmuds is cleared, initialize comparator 2. 2. if ctmuds is cleared, initialize the comparator voltage reference. 3. initialize the ctmu and enable time delay generation by setting the tgen bit. 4. set edg1stat. when ctmuds is cleared, as soon as c delay charges to the value of the voltage reference trip point, an out- put pulse is generated on ctpls. when ctmuds is set, as soon as ctdin is set, an output pulse is generated on ctpls. figure 27-4: typical co nnections and internal co nfiguration for pulse delay generation c2 cv ref ctpls current source comparator ctmu cted1 ctmui c delay edg1 pic18f87k22 ctmuds c1 external reference external comparator ctdin downloaded from: http:///
pic18f87k22 family ds39960d-page 400 ? 2009-2011 microchip technology inc. 27.8 measuring temperature with the ctmu module the ctmu, along with an internal diode, can be used to measure the temperature. the adc can be con- nected to the internal diode and the ctmu module can source the current to the diode. the adc reading will reflect the temperature. with the increase, the adc readings will go low. this can be used for low-cost temperature measurement applications. example 27-5: routine for temperature measurement using internal diode // initialize ctmu ctmuicon = 0x03; ctmuconhbits.ctmuen = 1; ctmuconlbits.edg1stat = 1; // initialize adc adcon0 = 0xe5; // enable adc and connect to internal diode adcon1 = 0x00; adcon2 = 0xbe; // right justified adcon0bits.go = 1; // start conversion while(adcon0bits.g0); temp = adres; // read adc results (inversely proportional to temperature) note: the temperature diode is not calibrated or standardized; the user must calibrate the diode to their application. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 401 pic18f87k22 family 27.9 operation during sleep/idle modes 27.9.1 sleep mode when the device enters any sleep mode, the ctmu module current source is always disabled. if the ctmu is performing an operation that depends on the current source when sleep mode is invoked, the operation may not terminate correctly. capacitance and time measurements may return erroneous values. 27.9.2 idle mode the behavior of the ctmu in idle mode is determined by the ctmusidl bit (ctmuconh<5>). if ctmusidl is cleared, the module will continue to operate in idle mode. if ctmusidl is set, the modules current source is disabled when the device enters idle mode. in this case, if the module is performing an operation when idle mode is invoked, the results will be similar to those with sleep mode. 27.10 effects of a reset on ctmu upon reset, all registers of the ctmu are cleared. this disables the ctmu module, turns off its current source and returns all configuration options to their default set- tings. the module needs to be re-initialized following any reset. if the ctmu is in the process of taking a measurement at the time of reset, the measurement will be lost. a partial charge may exist on the circuit that was being measured, which should be properly discharged before the ctmu makes subsequent attempts to make a measurement. the circuit is discharged by setting and clearing the idissen bit (ctmuconh<1>) while the a/d converter is connected to the appropriate channel. table 27-1: registers associated with ctmu module name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 ctmuconh ctmuen ctmusidl tgen edgen edgseqen idissen cttrig ctmuconl edg2pol edg2sel1 edg2sel0 edg1pol edg1sel1 edg1sel0 edg2stat edg1stat ctmuicon itrim5 itrim4 itrim3 itrim2 itrim1 itrim0 irng1 irng0 pir3 tmr5gif rc2if tx2if ctmuif ccp2if ccp1if rtccif pie3 tmr5gie rc2ie tx2ie ctmuie ccp2ie ccp1ie rtccie ipr3 tmr5gip rc2ip tx2ip ctmuip ccp2ip ccp1ip rtccip legend: = unimplemented, read as 0 . shaded cells are not used during eccp operation. downloaded from: http:///
pic18f87k22 family ds39960d-page 402 ? 2009-2011 microchip technology inc. notes: downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 403 pic18f87k22 family 28.0 special features of the cpu the pic18f87k22 family of devices includes several features intended to maximize reliability and minimize cost through elimination of external components. these include: oscillator selection resets: - power-on reset (por) - power-up timer (pwrt) - oscillator start-up timer (ost) - brown-out reset (bor) interrupts watchdog timer (wdt) and on-chip regulator fail-safe clock monitor two-speed start-up code protection id locations in-circuit serial programming? (icsp?) the oscillator can be configured for the application depending on frequency, power, accuracy and cost. all of the options are discussed in detail in section 3.0 oscillator configurations . a complete discussion of device resets and interrupts is available in previous sections of this data sheet. in addition to their power-up and oscillator start-up timers provided for resets, the pic18f87k22 family of devices has a watchdog timer, which is either perma- nently enabled via the configuration bits or software controlled (if configured as disabled). the inclusion of an internal rc oscillator (lf-intosc) also provides the additional benefits of a fail-safe clock monitor (fscm) and two-speed start-up. fscm provides for background monitoring of the peripheral clock and automatic switchover in the event of its fail- ure. two-speed start-up enables code to be executed almost immediately on start-up, while the primary clock source completes its start-up delays. all of these features are enabled and configured by setting the appropriate configuration register bits. 28.1 configuration bits the configuration bits can be programmed (read as 0 ) or left unprogrammed (read as 1 ) to select various device configurations. these bits are mapped starting at program memory location, 300000h. the user will note that address, 300000h, is beyond the user program memory space. in fact, it belongs to the configuration memory space (300000h-3fffffh), which can only be accessed using table reads and table writes. software programming of the configuration registers is done in a manner similar to programming the flash memory. the wr bit in the eecon1 register starts a self-timed write to the configuration register. in normal operation mode, a tblwt instruction, with the tblptr pointing to the configuration register, sets up the address and the data for the configuration register write. setting the wr bit starts a long write to the configuration register. the configuration registers are written a byte at a time. to write or erase a configuration cell, a tblwt instruction can write a 1 or a 0 into the cell. for additional details on flash programming, refer to section 7.5 writing to flash program memory . downloaded from: http:///
pic18f87k22 family ds39960d-page 404 ? 2009-2011 microchip technology inc. table 28-1: configuration bits and device ids file name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 default/ unprogrammed value 300000h config1l x i n s t soscsel1 soscsel0 intoscsel r e t e n -1-1 1--1 300001h config1h ieso fcmen pllcfg fosc3 fosc2 fosc1 fosc0 00-0 1000 300002h config2l borpwr1 borwpr0 borv1 borv0 boren1 boren0 pwrten -111 1111 300003h config2h wdtps4 wdtps3 wdtps2 wdtps1 wdtps0 wdten1 wdten0 -111 1111 300004h config3l wait ( 2 ) bw ( 2 ) abw1 ( 2 ) abw0 ( 2 ) eashft ( 2 ) r t c o s c ---- ---1 300005h config3h mclre msspmsk e c c p m x ( 2 ) ccp2mx 1--- 1-11 300006h config4l debug b b s i z 0 s t v r e n 1--1 ---1 300008h config5l cp7 ( 1 ) cp6 ( 1 ) cp5 ( 1 ) cp4 ( 1 ) cp3 cp2 cp1 cp0 1111 1111 300009h config5h cpd cpb 11-- ---- 30000ah config6l wrt7 ( 1 ) wrt6 ( 1 ) wrt5 ( 1 ) wrt4 ( 1 ) wrt3 wrt2 wrt1 wrt0 1111 1111 30000bh config6h wrtd wrtb wrtc 111- ---- 30000ch config7l ebtr7 ( 1 ) ebtr6 ( 1 ) ebtr5 ( 1 ) ebtr4 ( 1 ) ebtr3 ebtr2 ebtr1 ebtr0 1111 1111 30000dh config7h e b t r b -1-- ---- 3ffffeh devid1 ( 3 ) dev2 dev1 dev0 rev4 rev3 rev2 rev1 rev0 xxxx xxxx 3fffffh devid2 ( 3 ) dev10 dev9 dev8 dev7 dev6 dev5 dev4 dev3 xxxx xxxx legend: x = unknown, u = unchanged, - = unimplemented, q = value depends on condition. shaded cells are unimplemented, read as 0 . note 1: implemented only on the pic18f67k22 and pic18f87k22 devices. 2: implemented only on the 80-pin devices (pic18f8xk22). 3: see register 28-14 for devid1 values. devid registers are read-only and cannot be programmed by the user. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 405 pic18f87k22 family register 28-1: config1l: configuration register 1 low (byte address 300000h) u-0 r/p-1 u-0 r/p-1 r/p-1 r/p-1 u-0 r/p-1 x i n s t soscsel1 soscsel0 intoscsel reten bit 7 bit 0 legend: p = programmable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 unimplemented: read as 0 bit 6 xinst: extended instruction set enable bit 1 = instruction set extension and indexed addressing mode are enabled 0 = instruction set extension and indexed addressing mode are disabled (legacy mode) bit 5 unimplemented: read as 0 bit 4-3 soscsel<1:0>: sosc power selection and mode configuration bits 11 = high-power sosc circuit is selected 10 = digital (sclki) mode; i/o port functionality of rc0 and rc1 is enabled 01 = low-power sosc circuit is selected 00 = reserved bit 2 intoscsel: lf-intosc low-power enable bit 1 = lf-intosc is in high-power mode during sleep 0 = lf-intosc is in low-power mode during sleep bit 1 unimplemented: read as 0 bit 0 reten : v reg sleep enable bit 1 = regulator power while in sleep mode is controlled by vregslp (wdtcon<7>) 0 = regulator power while in sleep mode is controlled by sreten (wdtcon<4>). ultra low-power regulator is enabled. downloaded from: http:///
pic18f87k22 family ds39960d-page 406 ? 2009-2011 microchip technology inc. register 28-2: config1h: configuration register 1 high (byte address 300001h) r/p-0 r/p-0 u-0 u-0 r/p-1 r/p-0 r/p-0 r/p-0 ieso fcmen p l l c f g ( 1 ) fosc3 ( 2 ) fosc2 ( 2 ) fosc1 ( 2 ) fosc0 ( 2 ) bit 7 bit 0 legend: p = programmable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 ieso: internal/external oscillator switchover bit 1 = two-speed start-up is enabled 0 = two-speed start-up is disabled bit 6 fcmen: fail-safe clock monitor enable bit 1 = fail-safe clock monitor is enabled 0 = fail-safe clock monitor is disabled bit 5 unimplemented: read as 0 bit 4 pllcfg: 4x pll enable bit ( 1 ) 1 = oscillator is multiplied by 4 0 = oscillator is used directly bit 3-0 fosc<3:0>: oscillator selection bits ( 2 ) 1101 = ec1, ec oscillator (low power, dc-160 khz) 1100 = ec1io, ec oscillator with clkout function on ra6 (low power, dc-160 khz) 1011 = ec2, ec oscillator (medium power, 160 khz-16 mhz) 1010 = ec2io, ec oscillator with clkout function on ra6 (medium power, dc-160 khz-16 mhz) 1001 = intio1, internal rc oscillator with clkout function on ra6 1000 = intio2, internal rc oscillator 0111 = rc, external rc oscillator 0110 = rcio, external rc oscillator with cklout function on ra6 0101 = ec3, ec oscillator (high power, 4 mhz-64 mhz) 0100 = ec3io, ec oscillator with clkout function on ra6 (high power, 4 mhz-64 mhz) 0011 = hs1, hs oscillator (medium power, 4 mhz-16 mhz) 0010 = hs2, hs oscillator (high power, 16 mhz-25 mhz) 0001 = xt oscillator 0000 = lp oscillator note 1: not valid for the intiox pll mode. 2: intio + pll can be enabled only by the pllen bit (osctune<6>). other pll modes can be enabled by either the pllen bit or the pllcfg (config1h<4>) bit. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 407 pic18f87k22 family register 28-3: config2l: configuration register 2 low (byte address 300002h) u-0 r/p-1 r/p-1 r/p-1 r/p-1 r/p-1 r/p-1 r/p-1 b o r p w r 1 ( 1 ) borpwr0 ( 1 ) borv1 ( 1 ) borv0 ( 1 ) boren1 ( 2 ) boren0 ( 2 ) pwrten ( 2 ) bit 7 bit 0 legend: p = programmable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 unimplemented: read as 0 bit 6-5 borpwr<1:0>: bormv power-level bits ( 1 ) 11 = zpborvmv instead of bormv is selected 10 = bormv is set to a high-power level 01 = bormv is set to a medium power level 00 = bormv is set to a low-power level bit 4-3 borv<1:0>: brown-out reset voltage bits ( 1 ) 11 =v bormv is set to 1.8v 10 =v bormv is set to 2.0v 01 =v bormv is set to 2.7v 00 =v bormv is set to 3.0v bit 2-1 boren<1:0>: brown-out reset enable bits ( 2 ) 11 = brown-out reset is enabled in hardware only (sboren is disabled) 10 = brown-out reset is enabled in hardware only and disabled in sleep mode (sboren is disabled) 01 = brown-out reset is enabled and controlled by software (sboren is enabled) 00 = brown-out reset is disabled in hardware and software bit 0 pwrten : power-up timer enable bit ( 2 ) 1 = pwrt is disabled 0 = pwrt is enabled note 1: for the specifications, see section 31.1 dc characteristics: supply voltage pic18f87k22 family (industrial/extended) . 2: the power-up timer is decoupled from brown-out reset, allowing these features to be independently controlled. downloaded from: http:///
pic18f87k22 family ds39960d-page 408 ? 2009-2011 microchip technology inc. register 28-4: config2h: configuration register 2 high (byte address 300003h) u-0 r/p-1 r/p-1 r/p-1 r/p-1 r/p-1 r/p-1 r/p-1 wdtps4 wdtps3 wdtps2 wdtps1 wdtps0 wdten1 wdten0 bit 7 bit 0 legend: p = programmable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 unimplemented: read as 0 bit 6-2 wdtps<4:0>: watchdog timer postscale select bits 10101-11111 = reserved 10100 = 1:1,048,576 (4,194.304s) 10011 = 1:524,288 (2,097.152s) 10010 = 1:262,144 (1,048.576s) 10001 = 1:131,072 (524.288s) 10000 = 1:65,536 (262.144s) 01111 = 1:32,768 (131.072s) 01110 = 1:16,384 (65.536s) 01101 = 1:8,192 (32.768s) 01100 = 1:4,096 (16.384s) 01011 = 1:2,048 (8.192s) 01010 = 1:1,024 (4.096s) 01001 = 1:512 (2.048s) 01000 = 1:256 (1.024s) 00111 = 1:128 (512 ms) 00110 = 1:64 (256 ms) 00101 = 1:32 (128 ms) 00100 = 1:16 (64 ms) 00011 = 1:8 (32 ms) 00010 = 1:4 (16 ms) 00001 = 1:2 (8 ms) 00000 = 1:1 (4 ms) bit 1-0 wdten<1:0>: watchdog timer enable bits 11 = wdt is enabled in hardware; swdten bit is disabled 10 = wdt is controlled by the swdten bit setting 01 = wdt is enabled only while the device is active and disabled in sleep mode; swdten bit is disabled 00 = wdt is disabled in hardware; swdten bit is disabled downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 409 pic18f87k22 family register 28-5: config3l: configuration register 3 low (byte address 300004h) u-1 u-1 u-1 u-1 u-1 u-0 u-0 r/p-1 wait ( 1 ) bw ( 1 ) abw1 ( 1 ) abw0 ( 1 ) eashft ( 1 ) r t c o s c bit 7 bit 0 legend: p = programmable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 wait: external bus wait enable bit ( 1 ) 1 = wait states on the external bus are disabled 0 = wait states on the external bus are enabled and selected by memcon <5:4> bit 6 bw: data bus width select bit ( 1 ) 1 = 16-bit data width modes 0 = 8-bit data width modes bit 5-4 abw<1:0>: external memory bus configuration bits ( 1 ) 11 = 8-bit address mode (microcontroller mode) 10 = 12-bit address mode 01 = 16-bit address mode 00 = 20-bit address mode bit 3 eashft: external address bus shift enable bit ( 1 ) 1 = address shifting is enabled; external address is shifted to start at 000000h 0 = address shifting is disabled; external address bus reflects the pc value bit 2-1 unimplemented: read as 0 bit 0 rtcosc: rtcc reference clock select bit 1 = rtcc uses sosc as the reference clock 0 = rtcc uses lf-intosc as the reference clock note 1: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . downloaded from: http:///
pic18f87k22 family ds39960d-page 410 ? 2009-2011 microchip technology inc. register 28-6: config3h: configuration register 3 high (byte address 300005h) r/p-1 u-0 u-0 u-0 r/p-1 u-0 r/p-1 r/p-1 mclre msspmsk e c c p m x ( 1 ) ccp2mx bit 7 bit 0 legend: p = programmable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 mclre: mclr pin enable bit 1 = mclr pin is enabled; rg5 input pin is disabled 0 = rg5 input pin is enabled; mclr is disabled bit 6-4 unimplemented: read as 0 bit 3 msspmsk: mssp v3 7-bit address masking mode enable bit 1 = 7-bit address masking mode is enabled 0 = 5-bit address masking mode is enabled bit 2 unimplemented: read as 0 bit 1 eccpmx: eccp mux bit ( 1 ) 1 = - eccp1 (p1b/p1c) is multiplexed onto re6 and re5, ccp6 onto re6, and ccp7 onto re5 - eccp3 (p3b/p3c) is multiplexed onto re4 and re3, ccp8 onto re4, and ccp9 onto re3 0 = - eccp1 (p1b/p1c) is multiplexed onto rh7 and rh6, ccp6 onto rh7, and ccp7 ( 2 ) onto rh6 - eccp3 (p3b/p3c) is multiplexed onto rh5 and rh4, ccp8 onto rh5, and ccp9 ( 2 ) onto rh4 bit 0 ccp2mx: eccp2 mux bit 1 = eccp2 is multiplexed with rc1 0 = eccp2 is multiplexed with rb3 in extended microcontroller mode; eccp2 is multiplexed with re7 in microcontroller mode note 1: unimplemented on 64-pin devices (pic18f6xk22), read as 0 . 2: not implemented on 32k devices (pic18f65k22 and pic18f85k22). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 411 pic18f87k22 family register 28-7: config4l: configuration register 4 low (byte address 300006h) r/p-1 u-0 u-0 r/p-0 u-0 u-0 u-0 r/p-1 debug bbsiz0 s t v r e n bit 7 bit 0 legend: p = programmable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 debug : background debugger enable bit 1 = background debugger is disabled, rb6 and rb7 are configured as general purpose i/o pins 0 = background debugger is enabled, rb6 and rb7 are dedicated to in-circuit debug bit 6-5 unimplemented: read as 0 bit 4 bbsiz0: boot block size select bit 1 = 2 kw boot block size 0 = 1 kw boot block size bit 3-1 unimplemented: read as 0 bit 0 stvren: stack full/underflow reset enable bit 1 = stack full/underflow will cause reset 0 = stack full/underflow will not cause reset downloaded from: http:///
pic18f87k22 family ds39960d-page 412 ? 2009-2011 microchip technology inc. register 28-8: config5l: configuration register 5 low (byte address 300008h) r/c-1 r/c-1 r/c-1 r/c-1 r/c-1 r/c-1 r/c-1 r/c-1 cp7 ( 1 ) cp6 ( 1 ) cp5 ( 1 ) cp4 ( 1 ) cp3 cp2 cp1 cp0 bit 7 bit 0 legend: c = clearable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 cp7: code protection bit ( 1 ) 1 = block 7 is not code-protected ( 2 ) 0 = block 7 is code-protected ( 2 ) bit 6 cp6: code protection bit ( 1 ) 1 = block 6 is not code-protected ( 2 ) 0 = block 6 is code-protected ( 2 ) bit 5 cp5: code protection bit ( 1 ) 1 = block 5 is not code-protected ( 2 ) 0 = block 5 is code-protected ( 2 ) bit 4 cp4: code protection bit ( 1 ) 1 = block 4 is not code-protected ( 2 ) 0 = block 4 is code-protected ( 2 ) bit 3 cp3: code protection bit 1 = block 3 is not code-protected ( 2 ) 0 = block 3 is code-protected ( 2 ) bit 2 cp2: code protection bit 1 = block 2 is not code-protected ( 2 ) 0 = block 2 is code-protected ( 2 ) bit 1 cp1: code protection bit 1 = block 1 is not code-protected ( 2 ) 0 = block 1 is code-protected ( 2 ) bit 0 cp0: code protection bit 1 = block 0 is not code-protected ( 2 ) 0 = block 0 is code-protected ( 2 ) note 1: this bit is available only on pic18f67k22 and pic18f87k22 devices. 2: for the memory size of the blocks, see figure 28-6 . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 413 pic18f87k22 family register 28-9: config5h: configuration register 5 high (byte address 300009h) r/c-1 r/c-1 u-0 u-0 u-0 u-0 u-0 u-0 cpd cpb bit 7 bit 0 legend: c = clearable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 cpd: data eeprom code protection bit 1 = data eeprom is not code-protected 0 = data eeprom is code-protected bit 6 cpb: boot block code protection bit 1 = boot block is not code-protected ( 1 ) 0 = boot block is code-protected ( 1 ) bit 5-0 unimplemented: read as 0 note 1: for the memory size of the blocks, see figure 28-6 . the boot block size changes with bbsiz0. downloaded from: http:///
pic18f87k22 family ds39960d-page 414 ? 2009-2011 microchip technology inc. register 28-10: config6l: configuration register 6 low (byte address 30000ah) r/c-1 r/c-1 r/c-1 r/c-1 r/c-1 r/c-1 r/c-1 r/c-1 wrt7 ( 1 ) wrt6 ( 1 ) wrt5 ( 1 ) wrt4 ( 1 ) wrt3 wrt2 wrt1 wrt0 bit 7 bit 0 legend: c = clearable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 wrt7: write protection bit ( 1 ) 1 = block 7 is not write-protected ( 2 ) 0 = block 7 is write-protected ( 2 ) bit 6 wrt6: write protection bit ( 1 ) 1 = block 6 is not write-protected ( 2 ) 0 = block 6 is write-protected ( 2 ) bit 5 wrt5: write protection bit ( 1 ) 1 = block 5 is not write-protected ( 2 ) 0 = block 5 is write-protected ( 2 ) bit 4 wrt4: write protection bit ( 1 ) 1 = block 4 is not write-protected ( 2 ) 0 = block 4 is write-protected ( 2 ) bit 3 wrt3: write protection bit 1 = block 3 is not write-protected ( 2 ) 0 = block 3 is write-protected ( 2 ) bit 2 wrt2: write protection bit 1 = block 2 is not write-protected ( 2 ) 0 = block 2 is write-protected ( 2 ) bit 1 wrt1: write protection bit 1 = block 1 is not write-protected ( 2 ) 0 = block 1 is write-protected ( 2 ) bit 0 wrt0: write protection bit 1 = block 0 is not write-protected ( 2 ) 0 = block 0 is write-protected ( 2 ) note 1: this bit is available only on pic18f67k22 and pic18f87k22 devices. 2: for the memory size of the blocks, see figure 28-6 . downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 415 pic18f87k22 family register 28-11: config6h: configuration register 6 high (byte address 30000bh) r/c-1 r/c-1 r-1 u-0 u-0 u-0 u-0 u-0 wrtd wrtb wrtc ( 1 ) bit 7 bit 0 legend: c = clearable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 wrtd: data eeprom write protection bit 1 = data eeprom is not write-protected 0 = data eeprom is write-protected bit 6 wrtb: boot block write protection bit 1 = boot block is not write-protected ( 2 ) 0 = boot block is write-protected ( 2 ) bit 5 wrtc: configuration register write protection bit ( 1 ) 1 = configuration registers are not write-protected ( 2 ) 0 = configuration registers are write-protected ( 2 ) bit 4-0 unimplemented: read as 0 note 1: this bit is read-only in normal execution mode; it can be written only in program mode . 2: for the memory size of the blocks, see figure 28-6 . downloaded from: http:///
pic18f87k22 family ds39960d-page 416 ? 2009-2011 microchip technology inc. register 28-12: config7l: configuration register 7 low (byte address 30000ch) r/c-1 r/c-1 r/c-1 r/c-1 r/c-1 r/c-1 r/c-1 r/c-1 ebtr7 ( 1 , 3 ) ebtr6 ( 1 , 3 ) ebtr5 ( 1 , 3 ) ebtr4 ( 1 , 3 ) ebtr3 ( 3 ) ebtr2 ( 3 ) ebtr1 ( 3 ) ebtr0 ( 3 ) bit 7 bit 0 legend: c = clearable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 ebtr7: table read protection bit ( 1 , 3 ) 1 = block 7 is not protected from table reads executed in other blocks ( 2 ) 0 = block 7 is protected from table reads executed in other blocks ( 2 ) bit 6 ebtr6: table read protection bit ( 1 , 3 ) 1 = block 6 is not protected from table reads executed in other blocks ( 2 ) 0 = block 6 is protected from table reads executed in other blocks ( 2 ) bit 5 ebtr5: table read protection bit ( 1 , 3 ) 1 = block 5 is not protected from table reads executed in other blocks ( 2 ) 0 = block 5 is protected from table reads executed in other blocks ( 2 ) bit 4 ebtr4: table read protection bit ( 1 , 3 ) 1 = block 4 is not protected from table reads executed in other blocks ( 2 ) 0 = block 4 is protected from table reads executed in other blocks ( 2 ) bit 3 ebtr3: table read protection bit ( 3 ) 1 = block 3 is not protected from table reads executed in other blocks ( 2 ) 0 = block 3 is protected from table reads executed in other blocks ( 2 ) bit 2 ebtr2 : table read protection bit ( 3 ) 1 = block 2 is not protected from table reads executed in other blocks ( 2 ) 0 = block 2 is protected from table reads executed in other blocks ( 2 ) bit 1 ebtr1: table read protection bit ( 3 ) 1 = block 1 is not protected from table reads executed in other blocks ( 2 ) 0 = block 1 is protected from table reads executed in other blocks ( 2 ) bit 0 ebtr0: table read protection bit ( 3 ) 1 = block 0 is not protected from table reads executed in other blocks ( 2 ) 0 = block 0 is protected from table reads executed in other blocks ( 2 ) note 1: this bit is available only on pic18f67k22 and pic18f87k22 devices. 2: for the memory size of the blocks, see figure 28-6 3: enable the corresponding cpx bit to protect the block from external read operations. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 417 pic18f87k22 family register 28-13: config7h: configuration register 7 high (byte address 30000dh) u-0 r/c-1 u-0 u-0 u-0 u-0 u-0 u-0 ebtrb ( 2 ) bit 7 bit 0 legend: c = clearable bit r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 unimplemented: read as 0 bit 6 ebtrb: boot block table read protection bit ( 2 ) 1 = boot block is not protected from table reads executed in other blocks ( 1 ) 0 = boot block is protected from table reads executed in other blocks ( 1 ) bit 5-0 unimplemented: read as 0 note 1: for the memory size of the blocks, see figure 28-6 . 2: enable the corresponding cpx bit to protect the block from external read operations. downloaded from: http:///
pic18f87k22 family ds39960d-page 418 ? 2009-2011 microchip technology inc. register 28-14: devid1: device id register 1 for the pic18f87k22 family rrrrrrrr dev2 dev1 dev0 rev4 rev3 rev2 rev1 rev0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-5 dev<2:0>: device id bits devices with dev<10:3> of 0101 0010 (see devid2): 010 = pic18f65k22 000 = pic18f66k22 101 = pic18f85k22 011 = pic18f86k22 devices with dev<10:3> of 0101 0001 : 000 = pic18f67k22 010 = pic18f87k22 bit 4-0 rev<4:0>: revision id bits these bits are used to indicate the device revision. register 28-15: devid2: device id register 2 for the pic18f87k22 family rrrrrrrr dev10 ( 1 ) dev9 ( 1 ) dev8 ( 1 ) dev7 ( 1 ) dev6 ( 1 ) dev5 ( 1 ) dev4 ( 1 ) dev3 ( 1 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7-0 dev<10:3>: device id bits ( 1 ) these bits are used with the dev<2:0> bits in the device id register 1 to identify the part number. 0101 0010 = pic18f65k22, pic18f66k22, pic18f85k22 and pic18f86k22 0101 0001 = pic18f67k22 and pic18f87k22 note 1: these values for dev<10:3> may be shared with other devices. the specific device is always identified by using the entire dev<10:0> bit sequence. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 419 pic18f87k22 family 28.2 watchdog timer (wdt) for the pic18f87k22 family of devices, the wdt is driven by the lf-intosc source. when the wdt is enabled, the clock source is also enabled. the nominal wdt period is 4 ms and has the same stability as the lf-intosc oscillator. the 4 ms period of the wdt is multiplied by a 16-bit postscaler. any output of the wdt postscaler is selected by a multiplexer, controlled by bits in configuration register 2h. available periods range from 4 ms to 4,194 seconds (about one hour). the wdt and postscaler are cleared when any of the following events occur: a sleep or clrwdt instruction is executed, the ircf bits (osccon<6:4>) are changed or a clock failure has occurred. the wdt can be operated in one of four modes as determined by the wdten<1:0> (config2h<1:0> bits. the four modes are: wdt enabled wdt disabled wdt under software control, swdten (wdtcon<0>) wdt - enabled during normal operation - disabled during sleep figure 28-1: wdt block diagram note 1: the clrwdt and sleep instructions clear the wdt and postscaler counts when executed. 2: changing the setting of the ircf bits (osccon<6:4>) clears the wdt and postscaler counts. 3: when a clrwdt instruction is executed, the postscaler count will be cleared. intrc source wdt reset wdt counter programmable postscaler 1:1 to 1:1,048,576 enable wdt wdtps<3:0> clrwdt 4 reset all device resets sleep ? 128 change on ircf bits intrc source enable wdt swdten wdten<1:0> wdt enabled, swdten disabled wdt controlled with swdten bit setting wdt disabled in hardware, swdten disabled wdt enabled only while device is active, disabled wake-up from power-managed modes wdten1 wdten0 downloaded from: http:///
pic18f87k22 family ds39960d-page 420 ? 2009-2011 microchip technology inc. 28.2.1 control register register 28-16 shows the wdtcon register. this is a readable and writable register which contains a control bit that allows software to override the wdt enable configuration bit, but only if the configuration bit has disabled the wdt. table 28-2: summary of watchdog timer registers register 28-16: wdtcon: wat chdog timer control register r/w-0 u-0 r-x r/w-0 u-0 r/w-0 r/w-0 r/w-0 regslp u l p l v l s r e t e n ( 2 ) ulpen ulpsink swdten ( 1 ) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as 0 -n = value at por 1 = bit is set 0 = bit is cleared x = bit is unknown bit 7 regslp: regulator voltage sleep enable bit 1 = regulator goes into low-power mode when devices sleep mode is enabled 0 = regulator stays in normal operation mode when devices sleep mode is activated bit 6 unimplemented : read as 0 bit 5 ulplvl: ultra low-power wake-up output bit not valid unless ulpen = 1 . 1 = voltage on ra0 pin > ~ 0.5v 0 = voltage on ra0 pin < ~ 0.5v. bit 4 sreten: regulator voltage sleep disable bit ( 2 ) 1 = if reten (config1l<0>) = 0 and the regulator is enabled, the device goes into ultra low-power mode in sleep 0 = the regulator is on when the devices sleep mode is enabled and the low-power mode is controlled by regslp bit 3 unimplemented : read as 0 bit 2 ulpen: ultra low-power wake-up module enable bit 1 = ultra low-power wake-up module is enabled; ulplvl bit indicates the comparator output 0 = ultra low-power wake-up module is disabled bit 1 ulpsink: ultra low-power wake-up current sink enable bit not valid unless ulpen = 1 . 1 = ultra low-power wake-up current sink is enabled 0 = ultra low-power wake-up current sink is disabled bit 0 swdten: software controlled watchdog timer enable bit ( 1 ) 1 = watchdog timer is on 0 = watchdog timer is off note 1: this bit has no effect if the configuration bits, wdten<1:0>, are enabled. 2: this bit is available only when envreg = 1 and reten = 0 . name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 rcon ipen sboren cm ri to pd por bor wdtcon regslp u l p l v ls r e t e n ulpen ulpsink swdten legend: = unimplemented, read as 0 . shaded cells are not used by the watchdog timer. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 421 pic18f87k22 family 28.3 on-chip voltage regulator all of the pic18f87k22 family devices power their core digital logic at a nominal 3.3v. for designs that are required to operate at a higher typical voltage, such as 5v, all family devices incorporate two on-chip regula- tors that allow the device to run its core logic from v dd . those regulators are: normal on-chip regulator ultra low-power on-chip regulator the hardware configuration of these regulators is the same and is explained in section 28.3.1 regulator enable/disable by hardware . the regulators only differences relate to when the device enters sleep, as explained in section 28.3.2 operation of regulator in sleep . 28.3.1 regulator enable/disable by hardware the regulator can be enabled or disabled only by hard- ware. the regulator is controlled by the envreg pin and the v ddcore /v cap pin. 28.3.1.1 regulator enable mode tying v dd to the pin enables the regulator, which in turn, provides power to the core from the other v dd pins. when the regulator is enabled, a low-esr filter capac- itor must be connected to the v ddcore /v cap pin (see figure 28-2 ). this helps maintain the regulators stability. the recommended value for the filter capacitor is given in section 31.2 dc characteristics: power- down and supply current pic18f87k22 family (industrial/extended) . 28.3.1.2 regulator disable mode if the regulator is disabled by connecting v ss to the envreg pin, the power to the core is supplied directly by v dd . the voltage levels for v dd must not exceed the specified v ddcore levels. in regulator disabled mode, a 0.1 f capacitor should be connected to the v ddcore /v cap pin (see figure 28-2 ). when the regulator is being used, the overall voltage budget is very tight. the regulator should operate the device down to 1.8v. when v dd drops below 3.3v, the regulator no longer regulates, but the output voltage fol- lows the input until v dd reaches 1.8v. below this voltage, the output of the regulator output may drop to 0v. figure 28-2: conne ctions for the on-chip regulator v dd envreg v ddcore /v cap v ss c f 5v regulator enabled (envreg tied to v dd ): v dd envreg v ddcore /v cap v ss 3.3v (1) regulator disabled (envreg tied to v ss ): note 1: these are typical operating voltages. for the full operating ranges of v dd and v ddcore , see section 31.2 dc characteristics: power-down and supply current pic18f87k22 family (industrial/ extended) . pic18f87k22 pic18f87k22 0.1f downloaded from: http:///
pic18f87k22 family ds39960d-page 422 ? 2009-2011 microchip technology inc. 28.3.2 operation of regulator in sleep the difference in the two regulators operation arises with sleep mode. the ultra low-power regulator gives the device the lowest current in the regulator enabled mode. the on-chip regulator can go into a lower power mode, when the device goes to sleep, by setting the regslp bit (wdtcon<7>). this puts the regulator in a standby mode so that the device consumes much less current. the on-chip regulator can also go into the ultra low- power mode, which consumes the lowest current possible with the regulator enabled. this mode is controlled by the reten bit (config1l<0>) and sreten bit (wdtcon<4>). the various modes of regulator operation are shown in table 28-3 . when the ultra low-power regulator is in sleep mode, the internal reference voltages in the chip will be shut off and any interrupts referring to the internal reference will not wake up the device. if the bor or lvd is enabled, the regulator will keep the internal references on and the lowest possible current will not be achieved. when using the ultra low-power regulator in sleep mode, the device will take about 250 ? s, typical, to start executing the code after it wakes up. table 28-3: sleep mode regulator settings ( 1 ) regulator power mode vregslp wdtcon<7> sreten wdtcon<4> reten config1l<0> enabled normal operation (sleep) 0x1 enabled low-power mode (sleep) 1x1 enabled normal operation (sleep) 00x enabled low-power mode (sleep) 10x enabled ultra low-power mode (sleep) x10 note 1: x = indicates that v it status is invalid. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 423 pic18f87k22 family 28.4 two-speed start-up the two-speed start-up feature helps to minimize the latency period, from oscillator start-up to code execution, by allowing the microcontroller to use the intosc (lf-intosc, mf-intosc, hf-intosc) oscillator as a clock source until the primary clock source is available; it is enabled by setting the ieso configuration bit. two-speed start-up should be enabled only if the primary oscillator mode is lp, xt or hs (crystal-based modes). other sources do not require an ost start-up delay; for these, two-speed start-up should be disabled. when enabled, resets and wake-ups from sleep mode cause the device to configure itself to run from the internal oscillator block as the clock source, following the time-out of the power-up timer after a power-on reset is enabled. this allows almost immediate code execution while the primary oscillator starts and the ost is running. once the ost times out, the device automatically switches to pri_run mode. to use a higher clock speed on wake-up, the intosc or postscaler clock sources can be selected to provide a higher clock speed by setting bits, ircf<2:0>, immediately after reset. for wake-ups from sleep, the intosc or postscaler clock sources can be selected by setting the ircf<2:0> bits prior to entering sleep mode. in all other power-managed modes, two-speed start- up is not used. the device will be clocked by the currently selected clock source until the primary clock source becomes available. the setting of the ieso bit is ignored. 28.4.1 special considerations for using two-speed start-up while using the intosc oscillator in two-speed start- up, the device still obeys the normal command sequences for entering power-managed modes, including multiple sleep instructions (refer to section 4.1.4 multiple sleep commands ). in practice, this means that user code can change the scs<1:0> bit settings or issue sleep instructions before the ost times out. this would allow an application to briefly wake up, perform routine housekeeping tasks and return to sleep before the device starts to operate from the primary oscillator. user code can also check if the primary clock source is currently providing the device clocking by checking the status of the osts bit (osccon<3>). if the bit is set, the primary oscillator is providing the clock. otherwise, the internal oscillator block is providing the clock during wake-up from reset or sleep mode. figure 28-3: timing transition for tw o-speed start-up (intosc to hspll) q1 q3 q4 osc1 peripheral program pc pc + 2 intosc pll clock q1 pc + 6 q2 output q3 q4 q1 cpu clock pc + 4 clock counter q2 q2 q3 note 1: t ost = 1024 t osc ; t pll = 2 ms (approx). these intervals are not shown to scale. 2: clock transition typically occurs within 2-4 t osc . wake from interrupt event t pll (1) 12 n-1n clock osts bit set transition (2) multiplexer t ost (1) downloaded from: http:///
pic18f87k22 family ds39960d-page 424 ? 2009-2011 microchip technology inc. 28.5 fail-safe clock monitor the fail-safe clock monitor (fscm) allows the microcontroller to continue operation in the event of an external oscillator failure by automatically switching the device clock to the internal oscillator block. the fscm function is enabled by setting the fcmen configuration bit. when fscm is enabled, the lf-intosc oscillator runs at all times to monitor clocks to peripherals and provide a backup clock in the event of a clock failure. clock monitoring (shown in figure 28-4 ) is accomplished by creating a sample clock signal, which is the output from the lf-intosc, divided by 64. this allows ample time between fscm sample clocks for a peripheral clock edge to occur. the peripheral device clock and the sample clock are presented as inputs to the clock monitor (cm) latch. the cm is set on the falling edge of the device clock source, but cleared on the rising edge of the sample clock. figure 28-4: fscm block diagram clock failure is tested for on the falling edge of the sample clock. if a sample clock falling edge occurs while cm is still set, a clock failure has been detected ( figure 28-5 ). this causes the following: the fscm generates an oscillator fail interrupt by setting bit, oscfif (pir2<7>) the device clock source switches to the internal oscillator block (osccon is not updated to show the current clock source C this is the fail-safe condition) the wdt is reset during switchover, the postscaler frequency from the internal oscillator block may not be sufficiently stable for timing-sensitive applications. in these cases, it may be desirable to select another clock configuration and enter an alternate power-managed mode. this can be done to attempt a partial recovery or execute a controlled shut- down. see section 4.1.4 multiple sleep commands and section 28.4.1 special considerations for using two-speed start-up for more details. to use a higher clock speed on wake-up, the intosc or postscaler clock sources can be selected to provide a higher clock speed by setting bits, ircf<2:0>, immediately after reset. for wake-ups from sleep, the intosc or postscaler clock sources can be selected by setting the ircf<2:0> bits prior to entering sleep mode. the fscm will detect only failures of the primary or secondary clock sources. if the internal oscillator block fails, no failure would be detected nor would any action be possible. 28.5.1 fscm and the watchdog timer both the fscm and the wdt are clocked by the intosc oscillator. since the wdt operates with a separate divider and counter, disabling the wdt has no effect on the operation of the intosc oscillator when the fscm is enabled. as already noted, the clock source is switched to the intosc clock when a clock failure is detected. depending on the frequency selected by the ircf<2:0> bits, this may mean a substantial change in the speed of code execution. if the wdt is enabled with a small prescale value, a decrease in clock speed allows a wdt time-out to occur and a subsequent device reset. for this reason, fail-safe clock events also reset the wdt and postscaler, allowing it to start timing from when execution speed was changed, and decreasing the likelihood of an erroneous time-out. 28.5.2 exiting fail-safe operation the fail-safe condition is terminated by either a device reset or by entering a power-managed mode. on reset, the controller starts the primary clock source specified in configuration register 1h (with any required start-up delays that are required for the oscillator mode, such as the ost or pll timer). the intosc multiplexer provides the device clock until the primary clock source becomes ready (similar to a two- speed start-up). the clock source is then switched to the primary clock (indicated by the osts bit in the osccon register becoming set). the fail-safe clock monitor then resumes monitoring the peripheral clock. the primary clock source may never become ready during start-up. in this case, operation is clocked by the intosc multiplexer. the osccon register will remain in its reset state until a power-managed mode is entered. peripheral intrc 64 s c q (32 ? s) 488 hz (2.048 ms) clock monitor latch (cm) (edge-triggered) clock failure detected source clock q downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 425 pic18f87k22 family figure 28-5: fscm timing diagram 28.5.3 fscm interrupts in power-managed modes by entering a power-managed mode, the clock multiplexer selects the clock source selected by the osccon register. fail-safe clock monitoring of the power-managed clock source resumes in the power-managed mode. if an oscillator failure occurs during power-managed operation, the subsequent events depend on whether or not the oscillator failure interrupt flag bit is enabled (oscfif = 1 ). if enabled, code execution will be clocked by the intosc multiplexer. an automatic transition back to the failed clock source will not occur. if the interrupt is disabled, subsequent interrupts while in idle mode will cause the cpu to begin executing instructions while being clocked by the intosc source. 28.5.4 por or wake from sleep the fscm is designed to detect oscillator failure at any point after the device has exited power-on reset (por) or low-power sleep mode. when the primary device clock is ec, rc or intrc modes, monitoring can begin immediately following these events. for oscillator modes involving a crystal or resonator (hs, hspll, lp or xt), the situation is somewhat different. since the oscillator may require a start-up time considerably longer than the fcsm sample clock time, a false clock failure may be detected. to prevent this, the internal oscillator block is automatically config- ured as the device clock and functions until the primary clock is stable (when the ost and pll timers have timed out). this is identical to two-speed start-up mode. once the primary clock is stable, the intosc returns to its role as the fscm source. as noted in section 28.4.1 special considerations for using two-speed start-up , it is also possible to select another clock configuration and enter an alternate power-managed mode while waiting for the primary clock to become stable. when the new power- managed mode is selected, the primary clock is disabled. oscfif cm output device clock output sample clock failure detected oscillator failure note: the device clock is normally at a much higher frequency t han the sample clock. the relative frequencies in this example have been chosen for clarity. (q ) cm test cm test cm test note: the same logic that prevents false oscilla- tor failure interrupts on por, or wake from sleep, also prevents the detection of the oscillators failure to start at all following these events. this can be avoided by monitoring the osts bit and using a timing routine to determine if the oscillator is taking too long to start. even so, no oscillator failure interrupt will be flagged. downloaded from: http:///
pic18f87k22 family ds39960d-page 426 ? 2009-2011 microchip technology inc. 28.6 program verification and code protection the user program memory is divided into four blocks for the pic18fx5k22 and pic18fx6k22 devices, and eight blocks for pic18fx7k22 devices. one of these is a boot block of 1 or 2 kbytes. the remainder of the memory is divided into blocks on binary boundaries. each of the blocks has three code protection bits associated with them. they are: code-protect bit (cpx) write-protect bit (wrtx) external block table read bit (ebtrx) figure 28-6 shows the program memory organization for 48, 64, 96 and 128 kbyte devices and the specific code protection bit associated with each block. the actual locations of the bits are summarized in table 28-4 . figure 28-6: code-protect ed program memory for the pic18f87k22 family ( 1 ) 000000h200000h 3fffffh 01ffffh note 1: sizes of memory areas are not to scale. 2: boot block size is determined by the bbsiz0 bit (config4l<4>). code memory unimplemented read as 0 configuration and id space device/memory size (2) address pic18fx7k22 pic18fx6k22 pic18fx5k22 bbsiz = 1 bbsiz = 0 bbsiz = 1 bbsiz = 0 bbsiz = 1 bbsiz = 0 boot block 2kw boot block boot block 2kw boot block boot block 2kw boot block 0000h block 0 7kw block 0 7kw block 0 3kw 0800h block 0 6kw block 0 6kw block 0 2kw 1000h 17ffh block 1 4kw block 1 4kw 1800 3fff block 1 8kw block 1 8kw block 1 8kw block 1 8kw block 2 4kw block 2 4kw 4000h 5fffh block 3 4kw block 3 4kw 6000h 7fff block 2 8kw block 2 8kw block 2 8kw block 2 8kw 8000h bfffh block 3 8kw block 3 8kw block 3 8kw block 3 8kw c000h ffffh block 4 8kw block 4 8kw 10000h 13fffh block 5 8kw block 5 8kw 14000h 17fffh block 6 8kw block 6 8kw 18000h 1bfffh block 7 8kw block 7 8kw 1c000h 1ffffh downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 427 pic18f87k22 family table 28-4: summary of code protection registers 28.6.1 program memory code protection the program memory may be read to, or written from, any location using the table read and table write instructions. the device id may be read with table reads. the configuration registers may be read and written with the table read and table write instructions. in normal execution mode, the cpx bits have no direct effect. cpx bits inhibit external reads and writes. a block of user memory may be protected from table writes if the wrtx configuration bit is 0 . the ebtrx bits control table reads. for a block of user memory, with the ebtrx bit set to 0 , a table read instruction that executes from within that block is allowed to read. a table read instruction that executes from a location outside of that block is not allowed to read and will result in reading 0 s. figures 28-7 through 28-9 illustrate table write and table read protection. figure 28-7: table writ e (wrtx) disallowed file name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 300008h config5l cp7 ( 1 ) cp6 ( 1 ) cp5 ( 1 ) cp4 ( 1 ) cp3 cp2 cp1 cp0 300009h config5h cpd cpb 30000ah config6l wrt7 ( 1 ) wrt6 ( 1 ) wrt5 ( 1 ) wrt4 ( 1 ) wrt3 wrt2 wrt1 wrt0 30000bh config6h wrtd wrtb wrtc 30000ch config7l ebtr7 ( 1 ) ebtr6 ( 1 ) ebtr5 ( 1 ) ebtr4 ( 1 ) ebtr3 ebtr2 ebtr1 ebtr0 30000dh config7h ebtrb legend: shaded cells are unimplemented. note 1: this bit is available only on the pic18f67k22 and pic18f87k22 devices. note: code protection bits may only be written to a 0 from a 1 state. it is not possible to write a 1 to a bit in the 0 state. code protection bits are only set to 1 by a full chip erase or block erase function. the full chip erase and block erase functions can only be initiated via icsp or an external programmer. refer to the device programming specification for more information. 000000h 0007ffh 000800h 003fffh 004000h 007fffh 008000h 00bfffh 00c000h 00ffffh wrtb, ebtrb = 11 wrt0, ebtr0 = 01 wrt1, ebtr1 = 11 wrt2, ebtr2 = 11 wrt3, ebtr3 = 11 tblwt* tblptr = 0008ffh pc = 003ffeh tblwt* pc = 00bffeh register values program memory configuration bit settings results: all table writes are disabled to blockn whenever wrtx = 0 . downloaded from: http:///
pic18f87k22 family ds39960d-page 428 ? 2009-2011 microchip technology inc. figure 28-8: external block table read (ebtrx) disallowed figure 28-9: external block table read (ebtrx) allowed wrtb, ebtrb = 11 wrt0, ebtr0 = 10 wrt1, ebtr1 = 11 wrt2, ebtr2 = 11 wrt3, ebtr3 = 11 tblrd* tblptr = 0008ffh pc = 007ffeh results: all table reads from external blocks to blockn are disabled whenever ebtrx = 0 . the tablat register returns a value of 0 . register values program memory configuration bit settings 000000h 0007ffh 000800h 003fffh 004000h 007fffh 008000h 00bfffh 00c000h 00ffffh wrtb, ebtrb = 11 wrt0, ebtr0 = 10 wrt1, ebtr1 = 11 wrt2, ebtr2 = 11 wrt3, ebtr3 = 11 tblrd* tblptr = 0008ffh pc = 003ffeh register values program memory configuration bit settings results: table reads are permitted within blockn, even when ebtrbx = 0 . the tablat register returns the value of the data at the location, tblptr. 000000h 0007ffh 000800h 003fffh 004000h 007fffh 008000h 00bfffh 00c000h 00ffffh downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 429 pic18f87k22 family 28.6.2 data eeprom code protection the entire data eeprom is protected from external reads and writes by two bits: cpd and wrtd. cpd inhibits external reads and writes of data eeprom. wrtd inhibits internal and external writes to data eeprom. the cpu can always read data eeprom under normal operation, regardless of the protection bit settings. 28.6.3 configuration register protection the configuration registers can be write-protected. the wrtc bit controls protection of the configuration registers. in normal execution mode, the wrtc bit is readable only. wrtc can only be written via icsp or an external programmer. 28.7 id locations eight memory locations (200000h-200007h) are designated as id locations, where the user can store checksum or other code identification numbers. these locations are both readable and writable, during normal execution, through the tblrd and tblwt instructions or during program/verify. the id locations can be read when the device is code-protected. 28.8 in-circuit serial programming the pic18f87k22 family of devices can be serially programmed while in the end application circuit. this is simply done with two lines for clock and data, and three other lines for power, ground and the programming voltage. this allows customers to manufacture boards with unprogrammed devices and then program the microcontroller just before shipping the product. this also allows the most recent firmware or a custom firmware to be programmed. for the various programming modes, see the device programming specification. 28.9 in-circuit debugger when the debug configuration bit is programmed to a 0 , the in-circuit debugger (icd) functionality is enabled. this function allows simple debugging functions when used with mplab ? ide. when the microcontroller has this feature enabled, some resources are not available for general use. tab l e 2 8- 5 shows which resources are required by the background debugger. table 28-5: debugger resources to use the in-circuit debugger function of the micro- controller, the design must implement in-circuit serial programming connections to mclr /rg5/v pp , v dd , v ss , rb7 and rb6. this will interface to the in-circuit debugger module, available from microchip or one of the third-party development tool companies. i/o pins: rb6, rb7 stack: two levels program memory: 512 bytes data memory: 10 bytes downloaded from: http:///
pic18f87k22 family ds39960d-page 430 ? 2009-2011 microchip technology inc. notes: downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 431 pic18f87k22 family 29.0 instruction set summary the pic18f87k22 family of devices incorporates the standard set of 75 pic18 core instructions, as well as an extended set of 8 new instructions for the optimiza- tion of code that is recursive or that utilizes a software stack. the extended set is discussed later in this section. 29.1 standard instruction set the standard pic18 mcu instruction set adds many enhancements to the previous pic ? mcu instruction sets, while maintaining an easy migration from these pic mcu instruction sets. most instructions are a single program memory word (16 bits), but there are four instructions that require two program memory locations. each single-word instruction is a 16-bit word divided into an opcode, which specifies the instruction type and one or more operands, which further specify the operation of the instruction. the instruction set is highly orthogonal and is grouped into four basic categories: byte-oriented operations bit-oriented operations literal operations control operations the pic18 instruction set summary in table 29-2 lists byte-oriented , bit-oriented , literal and control operations. table 29-1 shows the opcode field descriptions. most byte-oriented instructions have three operands: 1. the file register (specified by f) 2. the destination of the result (specified by d) 3. the accessed memory (specified by a) the file register designator, f, specifies which file reg- ister is to be used by the instruction. the destination designator, d, specifies where the result of the operation is to be placed. if d is zero, the result is placed in the wreg register. if d is one, the result is placed in the file register specified in the instruction. all bit-oriented instructions have three operands: 1. the file register (specified by f) 2. the bit in the file register (specified by b) 3. the accessed memory (specified by a) the bit field designator, b, selects the number of the bit affected by the operation, while the file register desig- nator, f, represents the number of the file in which the bit is located. the literal instructions may use some of the following operands: a literal value to be loaded into a file register (specified by k) the desired fsr register to load the literal value into (specified by f) no operand required (specified by ) the control instructions may use some of the following operands: a program memory address (specified by n) the mode of the call or return instructions (specified by s) the mode of the table read and table write instructions (specified by m) no operand required (specified by ) all instructions are a single word, except for four double-word instructions. these instructions were made double-word to contain the required information in 32 bits. in the second word, the 4 msbs are 1 s. if this second word is executed as an instruction (by itself), it will execute as a nop . all single-word instructions are executed in a single instruction cycle, unless a conditional test is true or the program counter is changed as a result of the instruc- tion. in these cases, the execution takes two instruction cycles with the additional instruction cycle(s) executed as a nop . the double-word instructions execute in two instruction cycles. one instruction cycle consists of four oscillator periods. thus, for an oscillator frequency of 4 mhz, the normal instruction execution time is 1 ? s. if a conditional test is true, or the program counter is changed as a result of an instruction, the instruction execution time is 2 ? s. two-word branch instructions (if true) would take 3 ? s. figure 29-1 shows the general formats that the instruc- tions can have. all examples use the convention nnh to represent a hexadecimal number. the instruction set summary, shown in table 29-2 , lists the standard instructions recognized by the microchip mpasm tm assembler. section 29.1.1 standard instruction set provides a description of each instruction. downloaded from: http:///
pic18f87k22 family ds39960d-page 432 ? 2009-2011 microchip technology inc. table 29-1: opcode field descriptions field description a ram access bit: a = 0 : ram location in access ram (bsr register is ignored) a = 1 : ram bank is specified by bsr register bbb bit address within an 8-bit file register (0 to 7). bsr bank select register. used to select the current ram bank. c, dc, z, ov, n alu status bits: c arry, d igit c arry, z ero, ov erflow, n egative. d destination select bit: d = 0 : store result in wreg d = 1 : store result in file register f dest destination: either the wreg register or the specified register file location. f 8-bit register file address (00h to ffh), or 2-bit fsr designator (0h to 3h). f s 12-bit register file address (000h to fffh). this is the source address. f d 12-bit register file address (000h to fffh). this is the destination address. gie global interrupt enable bit. k literal field, constant data or label (may be either an 8-bit, 12-bit or a 20-bit value). label label name. mm the mode of the tblptr register for the table read and table write instructions. only used with table read and table write instructions: * no change to register (such as tblptr with table reads and writes) *+ post-increment register (such as tblptr with table reads and writes) *- post-decrement register (such as tblptr with table reads and writes) +* pre-increment register (such as tblptr with table reads and writes) n the relative address (2s complement number) for relative branch instructions or the direct address for call/branch and return instructions. pc program counter. pcl program counter low byte. pch program counter high byte. pclath program counter high byte latch. pclatu program counter upper byte latch. pd power-down bit. prodh product of multiply high byte. prodl product of multiply low byte. s fast call/return mode select bit: s = 0 : do not update into/from shadow registers s = 1 : certain registers loaded into/from shadow registers (fast mode) tblptr 21-bit table pointer (points to a program memory location). tablat 8-bit table latch. to time-out bit. tos top-of-stack. u unused or unchanged. wdt watchdog timer. wreg working register (accumulator). x dont care ( 0 or 1 ). the assembler will generate code with x = 0 . it is the recommended form of use for compatibility with all microchip software tools. z s 7-bit offset value for indirect addressing of register files (source). z d 7-bit offset value for indirect addressing of register files (destination). { } optional argument. [text] indicates an indexed address. (text) the contents of text . [expr] specifies bit n of the register indicated by the pointer expr . ? assigned to. < > register bit field. ? in the set of. italics user-defined term (font is courier new). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 433 pic18f87k22 family figure 29-1: general format for instructions byte-oriented file register operations 15 10 9 8 7 0 d = 0 for result destination to be wreg register opcode d a f (file #) d = 1 for result destination to be file register (f) a = 0 to force access bank bit-oriented file register operations 15 12 11 9 8 7 0 opcode b (bit #) a f (file #) b = 3-bit position of bit in file register (f) literal operations 15 8 7 0 opcode k (literal) k = 8-bit immediate value byte to byte move operations (2-word) 15 12 11 0 opcode f (source file #) call , goto and branch operations 15 8 7 0 opcode n<7:0> (literal) n = 20-bit immediate value a = 1 for bsr to select bank f = 8-bit file register address a = 0 to force access bank a = 1 for bsr to select bank f = 8-bit file register address 15 12 11 0 1111 n<19:8> (literal) 15 12 11 0 1111 f (destination file #) f = 12-bit file register address control operations example instruction addwf myreg, w, b movff myreg1, myreg2 bsf myreg, bit, b movlw 7fh goto label 15 8 7 0 opcode s n<7:0> (literal) 15 12 11 0 1111 n<19:8> (literal) call myfunc 15 11 10 0 opcode n<10:0> (literal) s = fast bit bra myfunc 15 8 7 0 opcode n<7:0> (literal) bc myfunc downloaded from: http:///
pic18f87k22 family ds39960d-page 434 ? 2009-2011 microchip technology inc. table 29-2: pic18f87k22 family instruction set mnemonic, operands description cycles 16-bit instruction word status affected notes msb lsb byte-oriented operations addwf addwfc andwf clrf comf cpfseq cpfsgt cpfslt decf decfsz dcfsnz incf incfsz infsnz iorwf movf movff movwf mulwf negf rlcf rlncf rrcf rrncf setf subfwb subwf subwfb swapf tstfsz xorwf f, d, a f, d, a f, d, a f, a f, d, a f, a f, a f, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f, d, a f s , f d f, af, a f, a f, d, a f, d, a f, d, a f, d, a f, a f, d, a f, d, a f, d, a f, d, a f, a f, d, a add wreg and f add wreg and carry bit to f and wreg with f clear f complement f compare f with wreg, skip = compare f with wreg, skip > compare f with wreg, skip < decrement f decrement f, skip if 0 decrement f, skip if not 0 increment f increment f, skip if 0 increment f, skip if not 0 inclusive or wreg with f move f move f s (source) to 1st word f d (destination) 2nd word move wreg to f multiply wreg with f negate f rotate left f through carry rotate left f (no carry) rotate right f through carry rotate right f (no carry) set f subtract f from wreg with borrow subtract wreg from f subtract wreg from f with borrow swap nibbles in f test f, skip if 0 exclusive or wreg with f 11 1 1 1 1 (2 or 3) 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 (2 or 3) 1 (2 or 3) 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 (2 or 3) 1 00100010 0001 0110 0001 0110 0110 0110 0000 0010 0100 0010 0011 0100 0001 0101 1100 1111 0110 0000 0110 0011 0100 0011 0100 0110 0101 0101 0101 0011 0110 0001 01da 00da 01da 101a 11da 001a 010a 000a 01da 11da 11da 10da 11da 10da 00da 00da ffff ffff 111a 001a 110a 01da 01da 00da 00da 100a 01da 11da 10da 10da 011a 10da ffffffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffffffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff c, dc, z, ov, n c, dc, z, ov, n z, n z z, n none none none c, dc, z, ov, n none none c, dc, z, ov, n none none z, n z, n none none none c, dc, z, ov, n c, z, n z, n c, z, n z, n none c, dc, z, ov, n c, dc, z, ov, n c, dc, z, ov, n none none z, n 1 , 2 1 , 2 1 , 2 21 , 2 44 1 , 2 1 , 2 , 3 , 4 1 , 2 , 3 , 4 1 , 2 1 , 2 , 3 , 4 41 , 2 1 , 2 11 , 2 1 , 2 1 , 2 1 , 2 41 , 2 note 1: when a port register is modified as a function of itself (e.g., movf portb, 1, 0 ), the value used will be that value present on the pins themselves. for example, if the data latch is 1 for a pin configured as input and is driven low by an external device, the data will be written back with a 0 . 2: if this instruction is executed on the tmr0 register (and, where applicable, d = 1 ), the prescaler will be cleared if assigned. 3: if the program counter (pc) is modified or a conditional test is true, the instruction requires two cycles. the second cycle is executed as a nop . 4: some instructions are two-word instructions. the second word of these i nstructions will be executed as a nop unless the first word of the instruction retrieves the information embedded in these 16 bits. this ensures that all program memory locations have a valid instruction. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 435 pic18f87k22 family bit-oriented operations bcf bsf btfsc btfss btg f, b, a f, b, a f, b, a f, b, a f, b, a bit clear f bit set f bit test f, skip if clear bit test f, skip if set bit toggle f 11 1 (2 or 3) 1 (2 or 3) 1 10011000 1011 1010 0111 bbba bbba bbba bbba bbba ffffffff ffff ffff ffff ffffffff ffff ffff ffff none none none none none 1 , 2 1 , 2 3 , 4 3 , 4 1 , 2 control operations bc bn bnc bnn bnov bnz bov bra bz call clrwdt daw goto nop nop pop push rcall reset retfie retlw return sleep nn n n n n n n n n, s n n s k s branch if carry branch if negative branch if not carry branch if not negative branch if not overflow branch if not zero branch if overflow branch unconditionally branch if zero call subroutine 1st word 2nd word clear watchdog timer decimal adjust wreg go to address 1st word 2nd word no operation no operation pop top of return stack (tos) push top of return stack (tos) relative call software device reset return from interrupt enable return with literal in wreg return from subroutine go into standby mode 1 (2)1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 1 (2) 2 1 (2) 2 1 1 2 1 1 1 1 2 1 2 2 2 1 11101110 1110 1110 1110 1110 1110 1101 1110 1110 1111 0000 0000 1110 1111 0000 1111 0000 0000 1101 0000 0000 0000 0000 0000 0010 0110 0011 0111 0101 0001 0100 0nnn 0000 110s kkkk 0000 0000 1111 kkkk 0000 xxxx 0000 0000 1nnn 0000 0000 1100 0000 0000 nnnnnnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0000 0000 kkkk kkkk 0000 xxxx 0000 0000 nnnn 1111 0001 kkkk 0001 0000 nnnnnnnn nnnn nnnn nnnn nnnn nnnn nnnn nnnn kkkk kkkk 0100 0111 kkkk kkkk 0000 xxxx 0110 0101 nnnn 1111 000s kkkk 001s 0011 none none none none none none none none none none to , pd c none none none none none none all gie/gieh, peie/giel none none to , pd 4 table 29-2: pic18f87k22 family instruction set (continued) mnemonic, operands description cycles 16-bit instruction word status affected notes msb lsb note 1: when a port register is modified as a function of itself (e.g., movf portb, 1, 0 ), the value used will be that value present on the pins themselves. for example, if the data latch is 1 for a pin configured as input and is driven low by an external device, the data will be written back with a 0 . 2: if this instruction is executed on the tmr0 register (and, where applicabl e, d = 1 ), the prescaler will be cleared if assigned. 3: if the program counter (pc) is modified or a conditional test is true, the instruction requires two cycles. the second cycle is executed as a nop . 4: some instructions are two-word instructions. the second word of these i nstructions will be executed as a nop unless the first word of the instruction retrieves the information embedded in these 16 bits. this ensures that all program memory locations have a valid instruction. downloaded from: http:///
pic18f87k22 family ds39960d-page 436 ? 2009-2011 microchip technology inc. literal operations addlw andlw iorlw lfsr movlb movlw mullw retlw sublw xorlw kk k f, k k k k k k k add literal and wreg and literal with wreg inclusive or literal with wreg move literal (12-bit) 2nd word to fsr(f) 1st word move literal to bsr<3:0> move literal to wreg multiply literal with wreg return with literal in wreg subtract wreg from literal exclusive or literal with wreg 11 1 2 1 1 1 2 1 1 00000000 0000 1110 1111 0000 0000 0000 0000 0000 0000 11111011 1001 1110 0000 0001 1110 1101 1100 1000 1010 kkkkkkkk kkkk 00ff kkkk 0000 kkkk kkkk kkkk kkkk kkkk kkkkkkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk c, dc, z, ov, n z, n z, n none none none none none c, dc, z, ov, n z, n data memory ? program memory operations tblrd* tblrd*+ tblrd*- tblrd+* tblwt* tblwt*+ tblwt*- tblwt+* table read table read with post-increment table read with post-decrement table read with pre-increment table write table write with post-increment table write with post-decrement table write with pre-increment 22 00000000 0000 0000 0000 0000 0000 0000 00000000 0000 0000 0000 0000 0000 0000 00000000 0000 0000 0000 0000 0000 0000 10001001 1010 1011 1100 1101 1110 1111 none none none none none none none none table 29-2: pic18f87k22 family instruction set (continued) mnemonic, operands description cycles 16-bit instruction word status affected notes msb lsb note 1: when a port register is modified as a function of itself (e.g., movf portb, 1, 0 ), the value used will be that value present on the pins themselves. for example, if the data latch is 1 for a pin configured as input and is driven low by an external device, the data will be written back with a 0 . 2: if this instruction is executed on the tmr0 register (and, where applicable, d = 1 ), the prescaler will be cleared if assigned. 3: if the program counter (pc) is modified or a conditional test is true, the instruction requires two cycles. the second cycle is executed as a nop . 4: some instructions are two-word instructions. the second word of these i nstructions will be executed as a nop unless the first word of the instruction retrieves the information embedded in these 16 bits. this ensures that all program memory locations have a valid instruction. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 437 pic18f87k22 family 29.1.1 standard instruction set addlw add literal to w syntax: addlw k operands: 0 ? k ? 255 operation: (w) + k ? w status affected: n, ov, c, dc, z encoding: 0000 1111 kkkk kkkk description: the contents of w are added to the 8-bit literal k and t he result is placed in w. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read literal k process data write to w example: addlw 15h before instruction w = 10h after instruction w = 25h addwf add w to f syntax: addwf f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (w) + (f) ? dest status affected: n, ov, c, dc, z encoding: 0010 01da ffff ffff description: add w to register f. if d is 0 , the result is stored in w. if d is 1 , the result is stored back in register f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example: addwf reg, 0, 0 before instruction w = 17h reg = 0c2h after instruction w = 0d9h reg = 0c2h note: all pic18 instructions may take an optional label argument preceding the instruction m nemonic for use in symbolic addressing. if a label is used, the instruction format then becomes: {labe l} instruction argument(s). downloaded from: http:///
pic18f87k22 family ds39960d-page 438 ? 2009-2011 microchip technology inc. addwfc add w and carry bit to f syntax: addwfc f {,d {,a}} operands: 0 ? f ? 255 d ?? [0,1] a ?? [0,1] operation: (w) + (f) + (c) ? dest status affected: n,ov, c, dc, z encoding: 0010 00da ffff ffff description: add w, the carry flag and data memory location f. if d is 0 , the result is placed in w. if d is 1 , the result is placed in data memory location f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example: addwfc reg, 0, 1 before instruction carry bit = 1 reg = 02h w=4 d h after instruction carry bit = 0 reg = 02h w = 50h andlw and literal with w syntax: andlw k operands: 0 ? k ? 255 operation: (w) .and. k ? w status affected: n, z encoding: 0000 1011 kkkk kkkk description: the contents of w are anded with the 8-bit literal k. the result is placed in w. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read literal k process data write to w example: andlw 05fh before instruction w=a 3 h after instruction w = 03h downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 439 pic18f87k22 family andwf and w with f syntax: andwf f {,d {,a}} operands: 0 ? f ? 255 d ?? [0,1] a ?? [0,1] operation: (w) .and. (f) ? dest status affected: n, z encoding: 0001 01da ffff ffff description: the contents of w are anded with register f. if d is 0 , the result is stored in w. if d is 1 , the result is stored back in register f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example: andwf reg, 0, 0 before instruction w = 17h reg = c2h after instruction w = 02h reg = c2h bc branch if carry syntax: bc n operands: -128 ? n ? 127 operation: if carry bit is 1 , (pc) + 2 + 2n ? pc status affected: none encoding: 1110 0010 nnnn nnnn description: if the carry bit is 1 , then the program will branch. the 2s complement number 2n is added to the pc. since the pc will have incremented to fetch the next instruction, the new address will be pc + 2 + 2n. this instruction is then a two-cycle instruction. words: 1 cycles: 1(2) q cycle activity: if jump: q1 q2 q3 q4 decode read literal n process data write to pc no operation no operation no operation no operation if no jump: q1 q2 q3 q4 decode read literal n process data no operation example: here bc 5 before instruction pc = address (here) after instruction if carry = 1 ; pc = address (here + 12) if carry = 0 ; pc = address (here + 2) downloaded from: http:///
pic18f87k22 family ds39960d-page 440 ? 2009-2011 microchip technology inc. bcf bit clear f syntax: bcf f, b {,a} operands: 0 ? f ? 255 0 ? b ? 7 a ?? [0,1] operation: 0 ? f status affected: none encoding: 1001 bbba ffff ffff description: bit b in register f is cleared. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write register f example: bcf flag_reg, 7, 0 before instruction flag_reg = c7h after instruction flag_reg = 47h bn branch if negative syntax: bn n operands: -128 ? n ? 127 operation: if negative bit is 1 , (pc) + 2 + 2n ? pc status affected: none encoding: 1110 0110 nnnn nnnn description: if the negative bit is 1 , then the program will branch. the 2s complement number 2n is added to the pc. since the pc will have incremented to fetch the next instruction, the new address will be pc + 2 + 2n. this instruction is then a two-cycle instruction. words: 1 cycles: 1(2) q cycle activity: if jump: q1 q2 q3 q4 decode read literal n process data write to pc no operation no operation no operation no operation if no jump: q1 q2 q3 q4 decode read literal n process data no operation example: here bn jump before instruction pc = address (here) after instruction if negative = 1 ; pc = address (jump) if negative = 0 ; pc = address (here + 2) downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 441 pic18f87k22 family bnc branch if not carry syntax: bnc n operands: -128 ? n ? 127 operation: if carry bit is 0 , (pc) + 2 + 2n ? pc status affected: none encoding: 1110 0011 nnnn nnnn description: if the carry bit is 0 , then the program will branch. the 2s complement number 2n is added to the pc. since the pc will have incremented to fetch the next instruction, the new address will be pc + 2 + 2n. this instruction is then a two-cycle instruction. words: 1 cycles: 1(2) q cycle activity: if jump: q1 q2 q3 q4 decode read literal n process data write to pc no operation no operation no operation no operation if no jump: q1 q2 q3 q4 decode read literal n process data no operation example: here bnc jump before instruction pc = address (here) after instruction if carry = 0 ; pc = address (jump) if carry = 1 ; pc = address (here + 2) bnn branch if not negative syntax: bnn n operands: -128 ? n ? 127 operation: if negative bit is 0 , (pc) + 2 + 2n ? pc status affected: none encoding: 1110 0111 nnnn nnnn description: if the negative bit is 0 , then the program will branch. the 2s complement number 2n is added to the pc. since the pc will have incremented to fetch the next instruction, the new address will be pc + 2 + 2n. this instruction is then a two-cycle instruction. words: 1 cycles: 1(2) q cycle activity: if jump: q1 q2 q3 q4 decode read literal n process data write to pc no operation no operation no operation no operation if no jump: q1 q2 q3 q4 decode read literal n process data no operation example: here bnn jump before instruction pc = address (here) after instruction if negative = 0 ; pc = address (jump) if negative = 1 ; pc = address (here + 2) downloaded from: http:///
pic18f87k22 family ds39960d-page 442 ? 2009-2011 microchip technology inc. bnov branch if not overflow syntax: bnov n operands: -128 ? n ? 127 operation: if overflow bit is 0 , (pc) + 2 + 2n ? pc status affected: none encoding: 1110 0101 nnnn nnnn description: if the overflow bit is 0 , then the program will branch. the 2s complement number 2n is added to the pc. since the pc will have incremented to fetch the next instruction, the new address will be pc + 2 + 2n. this instruction is then a two-cycle instruction. words: 1 cycles: 1(2) q cycle activity: if jump: q1 q2 q3 q4 decode read literal n process data write to pc no operation no operation no operation no operation if no jump: q1 q2 q3 q4 decode read literal n process data no operation example: here bnov jump before instruction pc = address (here) after instruction if overflow = 0 ; pc = address (jump) if overflow = 1 ; pc = address (here + 2) bnz branch if not zero syntax: bnz n operands: -128 ? n ? 127 operation: if zero bit is 0 , (pc) + 2 + 2n ? pc status affected: none encoding: 1110 0001 nnnn nnnn description: if the zero bit is 0 , then the program will branch. the 2s complement number 2n is added to the pc. since the pc will have incremented to fetch the next instruction, the new address will be pc + 2 + 2n. this instruction is then a two-cycle instruction. words: 1 cycles: 1(2) q cycle activity: if jump: q1 q2 q3 q4 decode read literal n process data write to pc no operation no operation no operation no operation if no jump: q1 q2 q3 q4 decode read literal n process data no operation example: here bnz jump before instruction pc = address (here) after instruction if zero = 0 ; pc = address (jump) if zero = 1 ; pc = address (here + 2) downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 443 pic18f87k22 family bra unconditional branch syntax: bra n operands: -1024 ? n ? 1023 operation: (pc) + 2 + 2n ? pc status affected: none encoding: 1101 0nnn nnnn nnnn description: add the 2s complement number 2n to the pc. since the pc will have incremented to fetch the next instruction, the new address will be pc + 2 + 2n. this instruction is a two-cycle instruction. words: 1 cycles: 2 q cycle activity: q1 q2 q3 q4 decode read literal n process data write to pc no operation no operation no operation no operation example: here bra jump before instruction pc = address (here) after instruction pc = address (jump) bsf bit set f syntax: bsf f, b {,a} operands: 0 ? f ? 255 0 ? b ? 7 a ?? [0,1] operation: 1 ? f status affected: none encoding: 1000 bbba ffff ffff description: bit b in register f is set. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write register f example: bsf flag_reg, 7, 1 before instruction flag_reg = 0ah after instruction flag_reg = 8ah downloaded from: http:///
pic18f87k22 family ds39960d-page 444 ? 2009-2011 microchip technology inc. btfsc bit test file, skip if clear syntax: btfsc f, b {,a} operands: 0 ? f ? 255 0 ? b ? 7 a ?? [0,1] operation: skip if (f) = 0 status affected: none encoding: 1011 bbba ffff ffff description: if bit b in register f is 0 , then the next instruction is skipped. if bit b is 0 , then the next instruction fetched during the current instruction execution is discarded and a nop is executed instead, making this a two-cycle instruction. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1(2) note: 3 cycles if skip and followed by a 2-word instruction. q cycle activity: q1 q2 q3 q4 decode read register f process data no operation if skip: q1 q2 q3 q4 no operation no operation no operation no operation if skip and followed by 2-word instruction: q1 q2 q3 q4 no operation no operation no operation no operation no operation no operation no operation no operation example: here false true btfsc: : flag, 1, 0 before instruction pc = address (here) after instruction if flag<1> = 0 ; pc = address (true) if flag<1> = 1 ; pc = address (false) btfss bit test file, skip if set syntax: btfss f, b {,a} operands: 0 ? f ? 255 0 ? b < 7 a ?? [0,1] operation: skip if (f) = 1 status affected: none encoding: 1010 bbba ffff ffff description: if bit b in register f is 1 , then the next instruction is skipped. if bit b is 1 , then the next instruction fetched during the current instruction execution is discarded and a nop is executed instead, making this a two-cycle instruction. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1(2) note: 3 cycles if skip and followed by a 2-word instruction. q cycle activity: q1 q2 q3 q4 decode read register f process data no operation if skip: q1 q2 q3 q4 no operation no operation no operation no operation if skip and followed by 2-word instruction: q1 q2 q3 q4 no operation no operation no operation no operation no operation no operation no operation no operation example: herefalse true btfss: : flag, 1, 0 before instruction pc = address (here) after instruction if flag<1> = 0 ; pc = address (false) if flag<1> = 1 ; pc = address (true) downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 445 pic18f87k22 family btg bit toggle f syntax: btg f, b {,a} operands: 0 ? f ? 255 0 ? b < 7 a ?? [0,1] operation: (f ) ? f status affected: none encoding: 0111 bbba ffff ffff description: bit b in data memory location, f, is inverted. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write register f example: btg portc, 4, 0 before instruction: portc = 0111 0101 [75h] after instruction: portc = 0110 0101 [65h] bov branch if overflow syntax: bov n operands: -128 ? n ? 127 operation: if overflow bit is 1 , (pc) + 2 + 2n ? pc status affected: none encoding: 1110 0100 nnnn nnnn description: if the overflow bit is 1 , then the program will branch. the 2s complement number 2n is added to the pc. since the pc will have incremented to fetch the next instruction, the new address will be pc + 2 + 2n. this instruction is then a two-cycle instruction. words: 1 cycles: 1(2) q cycle activity: if jump: q1 q2 q3 q4 decode read literal n process data write to pc no operation no operation no operation no operation if no jump: q1 q2 q3 q4 decode read literal n process data no operation example: here bov jump before instruction pc = address (here) after instruction if overflow = 1 ; pc = address (jump) if overflow = 0 ; pc = address (here + 2) downloaded from: http:///
pic18f87k22 family ds39960d-page 446 ? 2009-2011 microchip technology inc. bz branch if zero syntax: bz n operands: -128 ? n ? 127 operation: if zero bit is 1 , (pc) + 2 + 2n ? pc status affected: none encoding: 1110 0000 nnnn nnnn description: if the zero bit is 1 , then the program will branch. the 2s complement number 2n is added to the pc. since the pc will have incremented to fetch the next instruction, the new address will be pc + 2 + 2n. this instruction is then a two-cycle instruction. words: 1 cycles: 1(2) q cycle activity: if jump: q1 q2 q3 q4 decode read literal n process data write to pc no operation no operation no operation no operation if no jump: q1 q2 q3 q4 decode read literal n process data no operation example: here bz jump before instruction pc = address (here) after instruction if zero = 1 ; pc = address (jump) if zero = 0 ; pc = address (here + 2) call subroutine call syntax: call k {,s} operands: 0 ? k ? 1048575 s ?? [0,1] operation: (pc) + 4 ? tos, k ? pc<20:1>; if s = 1 (w) ? ws, (status) ? statuss, (bsr) ? bsrs status affected: none encoding: 1st word (k<7:0>) 2nd word(k<19:8>) 11101111 110s k 19 kkk k 7 kkk kkkk kkkk 0 kkkk 8 description: subroutine call of entire 2-mbyte memory range. first, return address (pc+ 4) is pushed onto the return stack. if s = 1 , the w, status and bsr registers are also pushed into their respective shadow registers, ws, statuss and bsrs. if s = 0 , no update occurs. then, the 20-bit value k is loaded into pc<20:1>. call is a two-cycle instruction. words: 2 cycles: 2 q cycle activity: q1 q2 q3 q4 decode read literal k<7:0>, push pc to stack read literal k<19:8>, write to pc no operation no operation no operation no operation example: here call there,1 before instruction pc = address (here) after instruction pc = address (there) tos = address (here + 4) ws = w bsrs = bsr statuss = status downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 447 pic18f87k22 family clrf clear f syntax: clrf f {,a} operands: 0 ? f ? 255 a ?? [0,1] operation: 000h ? f, 1 ? z status affected: z encoding: 0110 101a ffff ffff description: clears the contents of the specified register. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write register f example: clrf flag_reg,1 before instruction flag_reg = 5ah after instruction flag_reg = 00h clrwdt clear watchdog timer syntax: clrwdt operands: none operation: 000h ? wdt, 000h ? wdt postscaler, 1 ? to , 1 ? pd status affected: to , pd encoding: 0000 0000 0000 0100 description: clrwdt instruction resets the watchdog timer. it also resets the post- scaler of the wdt. status bits, to and pd , are set. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode no operation process data no operation example: clrwdt before instruction wdt counter = ? after instruction wdt counter = 00h wdt postscaler = 0 to = 1 pd = 1 downloaded from: http:///
pic18f87k22 family ds39960d-page 448 ? 2009-2011 microchip technology inc. comf complement f syntax: comf f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: f ? dest status affected: n, z encoding: 0001 11da ffff ffff description: the contents of register f are complemented. if d is 0 , the result is stored in w. if d is 1 , the result is stored back in register f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example: comf reg, 0, 0 before instruction reg = 13h after instruction reg = 13h w=e c h cpfseq compare f with w, skip if f = w syntax: cpfseq f {,a} operands: 0 ? f ? 255 a ? [0,1] operation: (f) C (w), skip if (f) = (w) (unsigned comparison) status affected: none encoding: 0110 001a ffff ffff description: compares the contents of data memory location f to the contents of w by performing an unsigned subtraction. if f = w , then the fetched instruction is discarded and a nop is executed instead, making this a two-cycle instruction. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1(2) note: 3 cycles if skip and followed by a 2-word instruction. q cycle activity: q1 q2 q3 q4 decode read register f process data no operation if skip: q1 q2 q3 q4 no operation no operation no operation no operation if skip and followed by 2-word instruction: q1 q2 q3 q4 no operation no operation no operation no operation no operation no operation no operation no operation example: here cpfseq reg, 0 nequal : equal : before instruction pc address = here w= ? reg = ? after instruction if reg = w; pc = address (equal) if reg ? w; pc = address (nequal) downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 449 pic18f87k22 family cpfsgt compare f with w, skip if f > w syntax: cpfsgt f {,a} operands: 0 ? f ? 255 a ? [0,1] operation: (f) C ?? w), skip if (f) > (w) (unsigned comparison) status affected: none encoding: 0110 010a ffff ffff description: compares the contents of data memory location f to the contents of the w by performing an unsigned subtraction. if the contents of f are greater than the contents of wreg , then the fetched instruction is discarded and a nop is executed instead, making this a two-cycle instruction. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1(2) note: 3 cycles if skip and followed by a 2-word instruction. q cycle activity: q1 q2 q3 q4 decode read register f process data no operation if skip: q1 q2 q3 q4 no operation no operation no operation no operation if skip and followed by 2-word instruction: q1 q2 q3 q4 no operation no operation no operation no operation no operation no operation no operation no operation example: here cpfsgt reg, 0 ngreater : greater : before instruction pc = address (here) w= ? after instruction if reg ? w; pc = address (greater) if reg ? w; pc = address (ngreater) cpfslt compare f with w, skip if f < w syntax: cpfslt f {,a} operands: 0 ? f ? 255 a ? [0,1] operation: (f) C ?? w), skip if (f) < (w) (unsigned comparison) status affected: none encoding: 0110 000a ffff ffff description: compares the contents of data memory location f to the contents of w by performing an unsigned subtraction. if the contents of f are less than the contents of w, then the fetched instruction is discarded and a nop is executed instead, making this a two-cycle instruction. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. words: 1 cycles: 1(2) note: 3 cycles if skip and followed by a 2-word instruction. q cycle activity: q1 q2 q3 q4 decode read register f process data no operation if skip: q1 q2 q3 q4 no operation no operation no operation no operation if skip and followed by 2-word instruction: q1 q2 q3 q4 no operation no operation no operation no operation no operation no operation no operation no operation example: here cpfslt reg, 1 nless : less : before instruction pc = address (here) w= ? after instruction if reg < w; pc = address (less) if reg ? w; pc = address (nless) downloaded from: http:///
pic18f87k22 family ds39960d-page 450 ? 2009-2011 microchip technology inc. daw decimal adjust w register syntax: daw operands: none operation: if [w<3:0> > 9] or [dc = 1 ], then (w<3:0>) + 6 ? w<3:0>; else (w<3:0>) ? w<3:0> if [w<7:4> > 9] or [c = 1 ], then (w<7:4>) + 6 ? w<7:4>; c = ? 1 ; else (w<7:4>) ? w<7:4> status affected: c encoding: 0000 0000 0000 0111 description: daw adjusts the 8-bit value in w, resulting from the earlier addition of two variables (each in packed bcd format) and produces a correct packed bcd result. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register w process data write w example 1: daw before instruction w=a 5 h c= 0 dc = 0 after instruction w = 05h c= 1 dc = 0 example 2: before instruction w=c e h c= 0 dc = 0 after instruction w = 34h c= 1 dc = 0 decf decrement f syntax: decf f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (f) C 1 ? dest status affected: c, dc, n, ov, z encoding: 0000 01da ffff ffff description: decrement register, f. if d is 0 , the result is stored in w. if d is 1 , the result is stored back in register f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example: decf cnt, 1, 0 before instruction cnt = 01h z= 0 after instruction cnt = 00h z= 1 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 451 pic18f87k22 family decfsz decrement f, skip if 0 syntax: decfsz f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (f) C 1 ? dest, skip if result = 0 status affected: none encoding: 0010 11da ffff ffff description: the contents of register f are decremented. if d is 0 , the result is placed in w. if d is 1 , the result is placed back in register f. if the result is 0 , the next instruction which is already fetched is discarded and a nop is executed instead, making it a two-cycle instruction. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1(2) note: 3 cycles if skip and followed by a 2-word instruction. q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination if skip: q1 q2 q3 q4 no operation no operation no operation no operation if skip and followed by 2-word instruction: q1 q2 q3 q4 no operation no operation no operation no operation no operation no operation no operation no operation example: here decfsz cnt, 1, 1 goto loop continue before instruction pc = address (here) after instruction cnt = cnt C 1 if cnt = 0 ; pc = address (continue) if cnt ? 0 ; pc = address (here + 2) dcfsnz decrement f, skip if not 0 syntax: dcfsnz f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (f) C 1 ? dest, skip if result ? 0 status affected: none encoding: 0100 11da ffff ffff description: the contents of register f are decremented. if d is 0 , the result is placed in w. if d is 1 , the result is placed back in register f. if the result is not 0 , the next instruction which is already fetched is discarded and a nop is executed instead, making it a two-cycle instruction. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1(2) note: 3 cycles if skip and followed by a 2-word instruction. q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination if skip: q1 q2 q3 q4 no operation no operation no operation no operation if skip and followed by 2-word instruction: q1 q2 q3 q4 no operation no operation no operation no operation no operation no operation no operation no operation example: here dcfsnz temp, 1, 0 zero : nzero : before instruction temp = ? after instruction temp = temp C 1, if temp = 0 ; pc = address (zero) if temp ? 0 ; pc = address (nzero) downloaded from: http:///
pic18f87k22 family ds39960d-page 452 ? 2009-2011 microchip technology inc. goto unconditional branch syntax: goto k operands: 0 ? k ? 1048575 operation: k ? pc<20:1> status affected: none encoding: 1st word (k<7:0>) 2nd word(k<19:8>) 11101111 1111 k 19 kkk k 7 kkk kkkk kkkk 0 kkkk 8 description: goto allows an unconditional branch anywhere within entire 2-mbyte memory range. the 20-bit value k is loaded into pc<20:1>. goto is always a two-cycle instruction. words: 2 cycles: 2 q cycle activity: q1 q2 q3 q4 decode read literal k<7:0>, no operation read literal k<19:8>, write to pc no operation no operation no operation no operation example: goto there after instruction pc = address (there) incf increment f syntax: incf f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (f) + 1 ? dest status affected: c, dc, n, ov, z encoding: 0010 10da ffff ffff description: the contents of register f are incremented. if d is 0 , the result is placed in w. if d is 1 , the result is placed back in register f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example: incf cnt, 1, 0 before instruction cnt = ffh z= 0 c= ? dc = ? after instruction cnt = 00h z= 1 c= 1 dc = 1 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 453 pic18f87k22 family incfsz increment f, skip if 0 syntax: incfsz f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (f) + 1 ? dest, skip if result = 0 status affected: none encoding: 0011 11da ffff ffff description: the contents of register f are incremented. if d is 0 , the result is placed in w. if d is 1 , the result is placed back in register f. if the result is 0 , the next instruction which is already fetched is discarded and a nop is executed instead, making it a two-cycle instruction. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1(2) note: 3 cycles if skip and followed by a 2-word instruction. q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination if skip: q1 q2 q3 q4 no operation no operation no operation no operation if skip and followed by 2-word instruction: q1 q2 q3 q4 no operation no operation no operation no operation no operation no operation no operation no operation example: here incfsz cnt, 1, 0 nzero : zero : before instruction pc = address (here) after instruction cnt = cnt + 1 if cnt = 0 ; pc = address (zero) if cnt ? 0 ; pc = address (nzero) infsnz increment f, skip if not 0 syntax: infsnz f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (f) + 1 ? dest, skip if result ? 0 status affected: none encoding: 0100 10da ffff ffff description: the contents of register f are incremented. if d is 0 , the result is placed in w. if d is 1 , the result is placed back in register f. if the result is not 0 , the next instruction which is already fetched is discarded and a nop is executed instead, making it a two-cycle instruction. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1(2) note: 3 cycles if skip and followed by a 2-word instruction. q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination if skip: q1 q2 q3 q4 no operation no operation no operation no operation if skip and followed by 2-word instruction: q1 q2 q3 q4 no operation no operation no operation no operation no operation no operation no operation no operation example: here infsnz reg, 1, 0 zero nzero before instruction pc = address (here) after instruction reg = reg + 1 if reg ? 0 ; pc = address (nzero) if reg = 0 ; pc = address (zero) downloaded from: http:///
pic18f87k22 family ds39960d-page 454 ? 2009-2011 microchip technology inc. iorlw inclusive or literal with w syntax: iorlw k operands: 0 ? k ? 255 operation: (w) .or. k ? w status affected: n, z encoding: 0000 1001 kkkk kkkk description: the contents of w are ored with the eight-bit literal k. the result is placed in w. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read literal k process data write to w example: iorlw 35h before instruction w=9 a h after instruction w=b f h iorwf inclusive or w with f syntax: iorwf f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (w) .or. (f) ? dest status affected: n, z encoding: 0001 00da ffff ffff description: inclusive or w with register f. if d is 0 , the result is placed in w. if d is 1 , the result is placed back in register f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example: iorwf result, 0, 1 before instruction result = 13h w = 91h after instruction result = 13h w = 93h downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 455 pic18f87k22 family lfsr load fsr syntax: lfsr f, k operands: 0 ? f ? 2 0 ? k ? 4095 operation: k ? fsrf status affected: none encoding: 11101111 11100000 00ff k 7 kkk k 11 kkk kkkk description: the 12-bit literal k is loaded into the file select register pointed to by f. words: 2 cycles: 2 q cycle activity: q1 q2 q3 q4 decode read literal k msb process data write literal k msb to fsrfh decode read literal k lsb process data write literal k to fsrfl example: lfsr 2, 3abh after instruction fsr2h = 03h fsr2l = abh movf move f syntax: movf f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: f ? dest status affected: n, z encoding: 0101 00da ffff ffff description: the contents of register f are moved to a destination dependent upon the status of d. if d is 0 , the result is placed in w. if d is 1 , the result is placed back in register f. location f can be anywhere in the 256-byte bank. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write w example: movf reg, 0, 0 before instruction reg = 22h w= f f h after instruction reg = 22h w = 22h downloaded from: http:///
pic18f87k22 family ds39960d-page 456 ? 2009-2011 microchip technology inc. movff move f to f syntax: movff f s ,f d operands: 0 ? f s ? 4095 0 ? f d ? 4095 operation: (f s ) ? f d status affected: none encoding: 1st word (source) 2nd word (destin.) 11001111 ffffffff ffffffff ffff s ffff d description: the contents of source register, f s , are moved to destination register f d . location of source f s can be anywhere in the 4096-byte data space (000h to fffh) and location of destination f d can also be anywhere from 000h to fffh. either source or destination can be w (a useful special situation). movff is particularly useful for transferring a data memory location to a peripheral register (such as the transmit buffer or an i/o port). the movff instruction cannot use the pcl, tosu, tosh or tosl as the destination register words: 2 cycles: 2 q cycle activity: q1 q2 q3 q4 decode read register f (src) process data no operation decode no operation no dummy read no operation write register f (dest) example: movff reg1, reg2 before instruction reg1 = 33h reg2 = 11h after instruction reg1 = 33h reg2 = 33h movlb move literal to low nibble in bsr syntax: movlb k operands: 0 ? k ? 255 operation: k ? bsr status affected: none encoding: 0000 0001 kkkk kkkk description: the eight-bit literal k is loaded into the bank select register (bsr). the value of bsr<7:4> always remains 0 regardless of the value of k 7 :k 4 . words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read literal k process data write literal k to bsr example: movlb 5 before instruction bsr register = 02h after instruction bsr register = 05h downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 457 pic18f87k22 family movlw move literal to w syntax: movlw k operands: 0 ? k ? 255 operation: k ? w status affected: none encoding: 0000 1110 kkkk kkkk description: the eight-bit literal k is loaded into w. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read literal k process data write to w example: movlw 5ah after instruction w=5 a h movwf move w to f syntax: movwf f {,a} operands: 0 ? f ? 255 a ? [0,1] operation: (w) ? f status affected: none encoding: 0110 111a ffff ffff description: move data from w to register f. location f can be anywhere in the 256-byte bank. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write register f example: movwf reg, 0 before instruction w=4 f h reg = ffh after instruction w=4 f h reg = 4fh downloaded from: http:///
pic18f87k22 family ds39960d-page 458 ? 2009-2011 microchip technology inc. mullw multiply literal with w syntax: mullw k operands: 0 ? k ? 255 operation: (w) x k ? prodh:prodl status affected: none encoding: 0000 1101 kkkk kkkk description: an unsigned multiplication is carried out between the contents of w and the 8-bit literal k. the 16-bit result is placed in the prodh:prodl register pair. prodh contains the high byte. w is unchanged. none of the status flags are affected. note that neither overflow nor carry is possible in this operation. a zero result is possible but not detected. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read literal k process data write registers prodh: prodl example: mullw 0c4h before instruction w= e 2 h prodh = ? prodl = ? after instruction w= e 2 h prodh = adh prodl = 08h mulwf multiply w with f syntax: mulwf f {,a} operands: 0 ? f ? 255 a ? [0,1] operation: (w) x (f) ? prodh:prodl status affected: none encoding: 0000 001a ffff ffff description: an unsigned multiplication is carried out between the contents of w and the register file location f. the 16-bit result is stored in the prodh:prodl register pair. prodh contains the high byte. both w and f are unchanged. none of the status flags are affected. note that neither overflow nor carry is possible in this operation. a zero result is possible but not detected. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write registers prodh: prodl example: mulwf reg, 1 before instruction w= c 4 h reg = b5h prodh = ? prodl = ? after instruction w= c 4 h reg = b5h prodh = 8ah prodl = 94h downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 459 pic18f87k22 family negf negate f syntax: negf f {,a} operands: 0 ? f ? 255 a ? [0,1] operation: (f ) + 1 ? f status affected: n, ov, c, dc, z encoding: 0110 110a ffff ffff description: location f is negated using twos complement. the result is placed in the data memory location f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write register f example: negf reg, 1 before instruction reg = 0011 1010 [3ah] after instruction reg = 1100 0110 [c6h] nop no operation syntax: nop operands: none operation: no operation status affected: none encoding: 00001111 0000xxxx 0000xxxx 0000xxxx description: no operation. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode no operation no operation no operation example: none. downloaded from: http:///
pic18f87k22 family ds39960d-page 460 ? 2009-2011 microchip technology inc. pop pop top of return stack syntax: pop operands: none operation: (tos) ? bit bucket status affected: none encoding: 0000 0000 0000 0110 description: the tos value is pulled off the return stack and is discarded. the tos value then becomes the previous value that was pushed onto the return stack. this instruction is provided to enable the user to properly manage the return stack to incorporate a software stack. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode no operation pop tos value no operation example: pop goto new before instruction tos = 0031a2h stack (1 level down) = 014332h after instruction tos = 014332h pc = new push push top of return stack syntax: push operands: none operation: (pc + 2) ? tos status affected: none encoding: 0000 0000 0000 0101 description: the pc + 2 is pushed onto the top of the return stack. the previous tos value is pushed down on the stack. this instruction allows implementing a software stack by modifying tos and then pushing it onto the return stack. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode push pc + 2 onto return stack no operation no operation example: push before instruction tos = 345ah pc = 0124h after instruction pc = 0126h tos = 0126h stack (1 level down) = 345ah downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 461 pic18f87k22 family rcall relative call syntax: rcall n operands: -1024 ? n ? 1023 operation: (pc) + 2 ? tos, (pc) + 2 + 2n ? pc status affected: none encoding: 1101 1nnn nnnn nnnn description: subroutine call with a jump up to 1k from the current location. first, return address (pc + 2) is pushed onto the stack. then, add the 2s complement number 2n to the pc. since the pc will have incremented to fetch the next instruction, the new address will be pc + 2 + 2n. this instruction is a two-cycle instruction. words: 1 cycles: 2 q cycle activity: q1 q2 q3 q4 decode read literal n push pc to stack process data write to pc no operation no operation no operation no operation example: here rcall jump before instruction pc = address (here) after instruction pc = address (jump) tos = address (here + 2) reset reset syntax: reset operands: none operation: reset all registers and flags that are affected by a mclr reset. status affected: all encoding: 0000 0000 1111 1111 description: this instruction provides a way to execute a mclr reset in software. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode start reset no operation no operation example: reset after instruction registers = reset value flags* = reset value downloaded from: http:///
pic18f87k22 family ds39960d-page 462 ? 2009-2011 microchip technology inc. retfie return from interrupt syntax: retfie {s} operands: s ? [0,1] operation: (tos) ? pc, 1 ? gie/gieh or peie/giel; if s = 1 , (ws) ? w, (statuss) ? status, (bsrs) ? bsr, pclatu, pclath are unchanged status affected: gie/gieh, peie/giel. encoding: 0000 0000 0001 000s description: return from interrupt. stack is popped and top-of-stack (tos) is loaded into the pc. interrupts are enabled by setting either the high or low-priority global interrupt enable bit. if s = 1 , the contents of the shadow registers ws, statuss and bsrs are loaded into their corresponding registers w, status and bsr. if s = 0 , no update of these registers occurs. words: 1 cycles: 2 q cycle activity: q1 q2 q3 q4 decode no operation no operation pop pc from stack set gieh or giel no operation no operation no operation no operation example: retfie 1 after interrupt pc = tos w= w s bsr = bsrs status = statuss gie/gieh, peie/giel = 1 retlw return literal to w syntax: retlw k operands: 0 ? k ? 255 operation: k ? w, (tos) ? pc, pclatu, pclath are unchanged status affected: none encoding: 0000 1100 kkkk kkkk description: w is loaded with the 8-bit literal k. the program counter is loaded from the top of the stack (the return address). the high address latch (pclath) remains unchanged. words: 1 cycles: 2 q cycle activity: q1 q2 q3 q4 decode read literal k process data pop pc from stack, write to w no operation no operation no operation no operation example: call table ; w contains table ; offset value ; w now has ; table value : table addwf pcl ; w = offset retlw k0 ; begin table retlw k1 ; : : retlw kn ; end of table before instruction w = 07h after instruction w = value of kn downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 463 pic18f87k22 family return return from subroutine syntax: return {s} operands: s ? [0,1] operation: (tos) ? pc; if s = 1 , (ws) ? w, (statuss) ? status, (bsrs) ? bsr, pclatu, pclath are unchanged status affected: none encoding: 0000 0000 0001 001s description: return from subroutine. the stack is popped and the top of the stack (tos) is loaded into the program counter. if s= 1 , the contents of the shadow registers ws, statuss and bsrs are loaded into their corresponding registers w, status and bsr. if s = 0 , no update of these registers occurs. words: 1 cycles: 2 q cycle activity: q1 q2 q3 q4 decode no operation process data pop pc from stack no operation no operation no operation no operation example: return after instruction: pc = tos rlcf rotate left f through carry syntax: rlcf f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (f) ? dest, (f<7>) ? c, (c) ? dest<0> status affected: c, n, z encoding: 0011 01da ffff ffff description: the contents of register f are rotated one bit to the left through the carry flag. if d is 0 , the result is placed in w. if d is 1 , the result is stored back in register f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example: rlcf reg, 0, 0 before instruction reg = 1110 0110 c= 0 after instruction reg = 1110 0110 w= 1100 1100 c= 1 c register f downloaded from: http:///
pic18f87k22 family ds39960d-page 464 ? 2009-2011 microchip technology inc. rlncf rotate left f (no carry) syntax: rlncf f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (f) ? dest, (f<7>) ? dest<0> status affected: n, z encoding: 0100 01da ffff ffff description: the contents of register f are rotated one bit to the left. if d is 0 , the result is placed in w. if d is 1 , the result is stored back in register f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example: rlncf reg, 1, 0 before instruction reg = 1010 1011 after instruction reg = 0101 0111 register f rrcf rotate right f through carry syntax: rrcf f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (f) ? dest, (f<0>) ? c, (c) ? dest<7> status affected: c, n, z encoding: 0011 00da ffff ffff description: the contents of register f are rotated one bit to the right through the carry flag. if d is 0 , the result is placed in w. if d is 1 , the result is placed back in register f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example: rrcf reg, 0, 0 before instruction reg = 1110 0110 c= 0 after instruction reg = 1110 0110 w= 0111 0011 c= 0 c register f downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 465 pic18f87k22 family rrncf rotate right f (no carry) syntax: rrncf f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (f) ? dest, (f<0>) ? dest<7> status affected: n, z encoding: 0100 00da ffff ffff description: the contents of register f are rotated one bit to the right. if d is 0 , the result is placed in w. if d is 1 , the result is placed back in register f. if a is 0 , the access bank will be selected, overriding the bsr value. if a is 1 , then the bank will be selected as per the bsr value. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example 1: rrncf reg, 1, 0 before instruction reg = 1101 0111 after instruction reg = 1110 1011 example 2: rrncf reg, 0, 0 before instruction w=? reg = 1101 0111 after instruction w= 1110 1011 reg = 1101 0111 register f setf set f syntax: setf f {,a} operands: 0 ? f ? 255 a ?? [0,1] operation: ffh ? f status affected: none encoding: 0110 100a ffff ffff description: the contents of the specified register are set to ffh. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write register f example: setf reg,1 before instruction reg = 5ah after instruction reg = ffh downloaded from: http:///
pic18f87k22 family ds39960d-page 466 ? 2009-2011 microchip technology inc. sleep enter sleep mode syntax: sleep operands: none operation: 00h ? wdt, 0 ? wdt postscaler, 1 ? to , 0 ? pd status affected: to , pd encoding: 0000 0000 0000 0011 description: the power-down status bit (pd ) is cleared. the time-out status bit (to ) is set. the watchdog timer and its postscaler are cleared. the processor is put into sleep mode with the oscillator stopped. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode no operation process data go to sleep example: sleep before instruction to =? pd =? after instruction to = 1 ? pd = 0 ? if wdt causes wake-up, this bit is cleared. subfwb subtract f from w with borrow syntax: subfwb f {,d {,a}} operands: 0 ?? f ?? 255 d ? [0,1] a ? [0,1] operation: (w) C (f) C (c ) ?? dest status affected: n, ov, c, dc, z encoding: 0101 01da ffff ffff description: subtract register f and carry flag (borrow) from w (2s complement method). if d is 0 , the result is stored in w. if d is 1 , the result is stored in register f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example 1: subfwb reg, 1, 0 before instruction reg = 3 w=2 c= 1 after instruction reg = ff w=2 c= 0 z= 0 n = 1 ; result is negative example 2: subfwb reg, 0, 0 before instruction reg = 2 w=5 c= 1 after instruction reg = 2 w=3 c= 1 z= 0 n = 0 ; result is positive example 3: subfwb reg, 1, 0 before instruction reg = 1 w=2 c= 0 after instruction reg = 0 w=2 c= 1 z = 1 ; result is zero n= 0 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 467 pic18f87k22 family sublw subtract w from literal syntax: sublw k operands: 0 ?? k ?? 255 operation: k C (w) ?? w status affected: n, ov, c, dc, z encoding: 0000 1000 kkkk kkkk description: w is subtracted from the eight-bit literal k. the result is placed in w. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read literal k process data write to w example 1: sublw 02h before instruction w = 01h c= ? after instruction w = 01h c= 1 ; result is positive z= 0 n= 0 example 2: sublw 02h before instruction w = 02h c= ? after instruction w = 00h c= 1 ; result is zero z= 1 n= 0 example 3: sublw 02h before instruction w = 03h c= ? after instruction w = ffh ; (2s complement) c= 0 ; result is negative z= 0 n= 1 subwf subtract w from f syntax: subwf f {,d {,a}} operands: 0 ?? f ?? 255 d ? [0,1] a ? [0,1] operation: (f) C (w) ?? dest status affected: n, ov, c, dc, z encoding: 0101 11da ffff ffff description: subtract w from register f (2s complement method). if d is 0 , the result is stored in w. if d is 1 , the result is stored back in register f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example 1: subwf reg, 1, 0 before instruction reg = 3 w=2 c= ? after instruction reg = 1 w=2 c = 1 ; result is positive z= 0 n= 0 example 2: subwf reg, 0, 0 before instruction reg = 2 w=2 c= ? after instruction reg = 2 w=0 c = 1 ; result is zero z= 1 n= 0 example 3: subwf reg, 1, 0 before instruction reg = 1 w=2 c= ? after instruction reg = ffh ;(2s complement) w=2 c = 0 ; result is negative z= 0 n= 1 downloaded from: http:///
pic18f87k22 family ds39960d-page 468 ? 2009-2011 microchip technology inc. subwfb subtract w from f with borrow syntax: subwfb f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (f) C (w) C (c ) ?? dest status affected: n, ov, c, dc, z encoding: 0101 10da ffff ffff description: subtract w and the carry flag (borrow) from register f (2s complement method). if d is 0 , the result is stored in w. if d is 1 , the result is stored back in register f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example 1: subwfb reg, 1, 0 before instruction reg = 19h (0001 1001) w=0 d h (0000 1101) c= 1 after instruction reg = 0ch (0000 1011) w=0 d h (0000 1101) c= 1 z= 0 n= 0 ; result is positive example 2: subwfb reg, 0, 0 before instruction reg = 1bh (0001 1011) w=1 a h (0001 1010) c= 0 after instruction reg = 1bh (0001 1011) w = 00h c= 1 z= 1 ; result is zero n= 0 example 3: subwfb reg, 1, 0 before instruction reg = 03h (0000 0011) w=0 e h (0000 1101) c= 1 after instruction reg = f5h (1111 0100) ; [2s comp] w=0 e h (0000 1101) c= 0 z= 0 n= 1 ; result is negative swapf swap f syntax: swapf f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (f<3:0>) ? dest<7:4>, (f<7:4>) ? dest<3:0> status affected: none encoding: 0011 10da ffff ffff description: the upper and lower nibbles of register f are exchanged. if d is 0 , the result is placed in w. if d is 1 , the result is placed in register f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example: swapf reg, 1, 0 before instruction reg = 53h after instruction reg = 35h downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 469 pic18f87k22 family tblrd table read syntax: tblrd ( *; *+; *-; +*) operands: none operation: if tblrd *, (prog mem (tblptr)) ? tablat; tblptr C no change if tblrd *+, (prog mem (tblptr)) ? tablat; (tblptr) + 1 ? tblptr if tblrd *-, (prog mem (tblptr)) ? tablat; (tblptr) C 1 ? tblptr if tblrd +*, (tblptr) + 1 ? tblptr; (prog mem (tblptr)) ? tablat status affected: none encoding: 0000 0000 0000 10nn nn=0 * =1 *+ =2 *- =3 +* description: this instruction is used to read the contents of program memory (p.m.). to address the program memory, a pointer called table pointer (tblptr) is used. the tblptr (a 21-bit pointer) points to each byte in the program memory. tblptr has a 2-mbyte address range. tblptr<0> = 0 :least significant byte of program memory word tblptr<0> = 1 :most significant byte of program memory word the tblrd instruction can modify the value of tblptr as follows: no change post-increment post-decrement pre-increment words: 1 cycles: 2 q cycle activity: q1 q2 q3 q4 decode no operation no operation no operation no operation no operation (read program memory) no operation no operation (write tablat) tblrd table read (continued) example 1: tblrd *+ ; before instruction tablat = 55h tblptr = 00a356h memory(00a356h) = 34h after instruction tablat = 34h tblptr = 00a357h example 2: tblrd +* ; before instruction tablat = aah tblptr = 01a357h memory(01a357h) = 12h memory(01a358h) = 34h after instruction tablat = 34h tblptr = 01a358h downloaded from: http:///
pic18f87k22 family ds39960d-page 470 ? 2009-2011 microchip technology inc. tblwt table write syntax: tblwt ( *; *+; *-; +*) operands: none operation: if tblwt*, (tablat) ? holding register; tblptr C no change if tblwt*+, (tablat) ? holding register; (tblptr) + 1 ? tblptr if tblwt*-, (tablat) ? holding register; (tblptr) C 1 ? tblptr if tblwt+*, (tblptr) + 1 ? tblptr; (tablat) ? holding register status affected: none encoding: 0000 0000 0000 11nn nn=0 * =1 *+ =2 *- =3 +* description: this instruction uses the 3 lsbs of tblptr to determine which of the 8 holding registers the tablat is written to. the holding registers are used to program the contents of program memory (p.m.). (refer to section 6.0 memory organization for additional details on programming flash memory.) the tblptr (a 21-bit pointer) points to each byte in the program memory. tblptr has a 2-mbyte address range. the lsb of the tblptr selects which byte of the program memory location to access. tblptr[0] = 0 :least significant byte of program memory word tblptr[0] = 1 :most significant byte of program memory word the tblwt instruction can modify the value of tblptr as follows: no change post-increment post-decrement pre-increment words: 1 cycles: 2 q cycle activity: q1 q2 q3 q4 decode no operation no operation no operation no operation no operation (read tablat) no operation no operation (write to holding register) tblwt table write (continued) example 1: tblwt *+; before instruction tablat = 55h tblptr = 00a356h holding register (00a356h) = ffh after instructions (table write completion) tablat = 55h tblptr = 00a357h holding register (00a356h) = 55h example 2: tblwt +*; before instruction tablat = 34h tblptr = 01389ah holding register (01389ah) = ffh holding register (01389bh) = ffh after instruction (table write completion) tablat = 34h tblptr = 01389bh holding register (01389ah) = ffh holding register (01389bh) = 34h downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 471 pic18f87k22 family tstfsz test f, skip if 0 syntax: tstfsz f {,a} operands: 0 ? f ? 255 a ? [0,1] operation: skip if f = 0 status affected: none encoding: 0110 011a ffff ffff description: if f = 0 , the next instruction fetched during the current instruction execution is discarded and a nop is executed, making this a two-cycle instruction. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1(2) note: 3 cycles if skip and followed by a 2-word instruction. q cycle activity: q1 q2 q3 q4 decode read register f process data no operation if skip: q1 q2 q3 q4 no operation no operation no operation no operation if skip and followed by 2-word instruction: q1 q2 q3 q4 no operation no operation no operation no operation no operation no operation no operation no operation example: here tstfsz cnt, 1 nzero : zero : before instruction pc = address (here) after instruction if cnt = 00h, pc = address (zero) if cnt ? 00h, pc = address (nzero) xorlw exclusive or literal with w syntax: xorlw k operands: 0 ?? k ?? 255 operation: (w) .xor. k ?? w status affected: n, z encoding: 0000 1010 kkkk kkkk description: the contents of w are xored with the 8-bit literal k. the result is placed in w. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read literal k process data write to w example: xorlw 0afh before instruction w=b 5 h after instruction w=1 a h downloaded from: http:///
pic18f87k22 family ds39960d-page 472 ? 2009-2011 microchip technology inc. xorwf exclusive or w with f syntax: xorwf f {,d {,a}} operands: 0 ? f ? 255 d ? [0,1] a ? [0,1] operation: (w) .xor. (f) ?? dest status affected: n, z encoding: 0001 10da ffff ffff description: exclusive or the contents of w with register f. if d is 0 , the result is stored in w. if d is 1 , the result is stored back in the register f. if a is 0 , the access bank is selected. if a is 1 , the bsr is used to select the gpr bank. if a is 0 and the extended instruction set is enabled, this instruction operates in indexed literal offset addressing mode whenever f ?? 95 (5fh). see section 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode for details. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example: xorwf reg, 1, 0 before instruction reg = afh w=b 5 h after instruction reg = 1ah w=b 5 h downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 473 pic18f87k22 family 29.2 extended instruction set in addition to the standard 75 instructions of the pic18 instruction set, the pic18f87k22 family of devices also provides an optional extension to the core cpu func- tionality. the added features include eight additional instructions that augment indirect and indexed addressing operations and the implementation of indexed literal offset addressing for many of the standard pic18 instructions. the additional features of the extended instruction set are enabled by default on unprogrammed devices. users must properly set or clear the xinst configura- tion bit during programming to enable or disable these features. the instructions in the extended set can all be classified as literal operations, which either manipulate the file select registers, or use them for indexed addressing. two of the instructions, addfsr and subfsr , each have an additional special instantiation for using fsr2. these versions ( addulnk and subulnk ) allow for automatic return after execution. the extended instructions are specifically implemented to optimize re-entrant program code (that is, code that is recursive or that uses a software stack) written in high-level languages, particularly c. among other things, they allow users working in high-level languages to perform certain operations on data structures more efficiently. these include: dynamic allocation and deallocation of software stack space when entering and leaving subroutines function pointer invocation software stack pointer manipulation manipulation of variables located in a software stack a summary of the instructions in the extended instruc- tion set is provided in tab l e 2 9- 3 . detailed descriptions are provided in section 29.2.2 extended instruction set . the opcode field descriptions in tab l e 2 9- 1 (page 432 ) apply to both the standard and extended pic18 instruction sets. 29.2.1 extended instruction syntax most of the extended instructions use indexed argu- ments, using one of the file select registers and some offset to specify a source or destination register. when an argument for an instruction serves as part of indexed addressing, it is enclosed in square brackets ([ ]). this is done to indicate that the argument is used as an index or offset. the mpasm? assembler will flag an error if it determines that an index or offset value is not bracketed. when the extended instruction set is enabled, brackets are also used to indicate index arguments in byte-oriented and bit-oriented instructions. this is in addition to other changes in their syntax. for more details, see section 29.2.3.1 extended instruction syntax with standard pic18 commands . table 29-3: extensions to the pic18 instruction set note: the instruction set extension and the indexed literal offset addressing mode were designed for optimizing applications written in c; the user may likely never use these instructions directly in assembler. the syntax for these commands is provided as a reference for users who may be reviewing code that has been generated by a compiler. note: in the past, square brackets have been used to denote optional arguments in the pic18 and earlier instruction sets. in this text and going forward, optional arguments are denoted by braces ({ }). mnemonic, operands description cycles 16-bit instruction word status affected msb lsb addfsr addulnk callw movsf movss pushl subfsr subulnk f, k k z s , f d z s , z d k f, k k add literal to fsr add literal to fsr2 and return call subroutine using wreg move z s (source) to 1st word f d (destination) 2nd word move z s (source) to 1st word z d (destination) 2nd word store literal at fsr2, decrement fsr2 subtract literal from fsr subtract literal from fsr2 and return 12 2 2 2 1 1 2 11101110 0000 1110 1111 1110 1111 1110 1110 1110 1000 1000 0000 1011 ffff 1011 xxxx 1010 1001 1001 ffkk 11kk 0001 0zzzffff 1zzz xzzz kkkk ffkk 11kk kkkkkkkk 0100 zzzz ffff zzzz zzzz kkkk kkkk kkkk none none none none none none none none downloaded from: http:///
pic18f87k22 family ds39960d-page 474 ? 2009-2011 microchip technology inc. 29.2.2 extended instruction set addfsr add literal to fsr syntax: addfsr f, k operands: 0 ? k ? 63 f ? [ 0, 1, 2 ] operation: fsr(f) + k ? fsr(f) status affected: none encoding: 1110 1000 ffkk kkkk description: the 6-bit literal k is added to the contents of the fsr specified by f. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read literal k process data write to fsr example: addfsr 2, 23h before instruction fsr2 = 03ffh after instruction fsr2 = 0422h addulnk add literal to fsr2 and return syntax: addulnk k operands: 0 ? k ? 63 operation: fsr2 + k ? fsr2, (tos) ?? pc status affected: none encoding: 1110 1000 11kk kkkk description: the 6-bit literal k is added to the contents of fsr2. a return is then executed by loading the pc with the tos. the instruction takes two cycles to execute; a nop is performed during the second cycle. this may be thought of as a special case of the addfsr instruction, where f = 3 (binary 11 ); it operates only on fsr2. words: 1 cycles: 2 q cycle activity: q1 q2 q3 q4 decode read literal k process data write to fsr no operation no operation no operation no operation example: addulnk 23h before instruction fsr2 = 03ffh pc = 0100h after instruction fsr2 = 0422h pc = (tos) note: all pic18 instructions may take an optional label argument preceding the instruction m nemonic for use in symbolic addressing. if a label is used, the instruction format then becomes: {label} i nstruction argument(s). downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 475 pic18f87k22 family callw subroutine call using wreg syntax: callw operands: none operation: (pc + 2) ? tos, (w) ? pcl, (pclath) ? pch, (pclatu) ? pcu status affected: none encoding: 0000 0000 0001 0100 description first, the return address (pc + 2) is pushed onto the return stack. next, the contents of w are written to pcl; the existing value is discarded. then, the contents of pclath and pclatu are latched into pch and pcu, respectively. the second cycle is executed as a nop instruction while the new next instruction is fetched. unlike call , there is no option to update w, status or bsr. words: 1 cycles: 2 q cycle activity: q1 q2 q3 q4 decode read wreg push pc to stack no operation no operation no operation no operation no operation example: here callw before instruction pc = address (here) pclath = 10h pclatu = 00h w = 06h after instruction pc = 001006h tos = address (here + 2) pclath = 10h pclatu = 00h w = 06h movsf move indexed to f syntax: movsf [z s ], f d operands: 0 ? z s ? 127 0 ? f d ? 4095 operation: ((fsr2) + z s ) ? f d status affected: none encoding: 1st word (source) 2nd word (destin.) 11101111 1011ffff 0zzzffff zzzz s ffff d description: the contents of the source register are moved to destination register f d . the actual address of the source register is determined by adding the 7-bit literal offset z s , in the first word, to the value of fsr2. the address of the destination register is specified by the 12-bit literal f d in the second word. both addresses can be anywhere in the 4096-byte data space (000h to fffh). the movsf instruction cannot use the pcl, tosu, tosh or tosl as the destination register. if the resultant source address points to an indirect addressing register, the value returned will be 00h. words: 2 cycles: 2 q cycle activity: q1 q2 q3 q4 decode determine source addr determine source addr read source reg decode no operation no dummy read no operation write register f (dest) example: movsf [05h], reg2 before instruction fsr2 = 80h contents of 85h = 33h reg2 = 11h after instruction fsr2 = 80h contents of 85h = 33h reg2 = 33h downloaded from: http:///
pic18f87k22 family ds39960d-page 476 ? 2009-2011 microchip technology inc. movss move indexed to indexed syntax: movss [z s ], [z d ] operands: 0 ? z s ? 127 0 ? z d ? 127 operation: ((fsr2) + z s ) ? ((fsr2) + z d ) status affected: none encoding: 1st word (source) 2nd word (dest.) 11101111 1011xxxx 1zzzxzzz zzzz s zzzz d description the contents of the source register are moved to the destination register. the addresses of the source and destination registers are determined by adding the 7-bit literal offsets, z s or z d , respectively, to the value of fsr2. both registers can be located anywhere in the 4096-byte data memory space (000h to fffh). the movss instruction cannot use the pcl, tosu, tosh or tosl as the destination register. if the resultant source address points to an indirect addressing register, the value returned will be 00h. if the resultant destination address points to an indirect addressing register, the instruction will execute as a nop . words: 2 cycles: 2 q cycle activity: q1 q2 q3 q4 decode determine source addr determine source addr read source reg decode determine dest addr determine dest addr write to dest reg example: movss [05h], [06h] before instruction fsr2 = 80h contents of 85h = 33h contents of 86h = 11h after instruction fsr2 = 80h contents of 85h = 33h contents of 86h = 33h pushl store literal at fsr2, decrement fsr2 syntax: pushl k operands: 0 ??? k ? 255 operation: k ? (fsr2), fsr2 C 1 ? fsr2 status affected: none encoding: 1110 1010 kkkk kkkk description: the 8-bit literal k is written to the data memory address specified by fsr2. fsr2 is decremented by 1 after the operation. this instruction allows users to push values onto a software stack. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read k process data write to destination example: pushl 08h before instruction fsr2h:fsr2l = 01ech memory (01ech) = 00h after instruction fsr2h:fsr2l = 01ebh memory (01ech) = 08h downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 477 pic18f87k22 family subfsr subtract literal from fsr syntax: subfsr f, k operands: 0 ? k ? 63 f ? [ 0, 1, 2 ] operation: fsrf C k ? fsrf status affected: none encoding: 1110 1001 ffkk kkkk description: the 6-bit literal k is subtracted from the contents of the fsr specified by f. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example: subfsr 2, 23h before instruction fsr2 = 03ffh after instruction fsr2 = 03dch subulnk subtract literal from fsr2 and return syntax: subulnk k operands: 0 ? k ? 63 operation: fsr2 C k ? fsr2, (tos) ?? pc status affected: none encoding: 1110 1001 11kk kkkk description: the 6-bit literal k is subtracted from the contents of the fsr2. a return is then executed by loading the pc with the tos. the instruction takes two cycles to execute; a nop is performed during the second cycle. this may be thought of as a special case of the subfsr instruction, where f = 3 (binary 11 ); it operates only on fsr2. words: 1 cycles: 2 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination no operation no operation no operation no operation example: subulnk 23h before instruction fsr2 = 03ffh pc = 0100h after instruction fsr2 = 03dch pc = (tos) downloaded from: http:///
pic18f87k22 family ds39960d-page 478 ? 2009-2011 microchip technology inc. 29.2.3 byte-oriented and bit-oriented instructions in indexed literal offset mode in addition to eight new commands in the extended set, enabling the extended instruction set also enables indexed literal offset addressing ( section 6.6.1 indexed addressing with literal offset ). this has a significant impact on the way that many commands of the standard pic18 instruction set are interpreted. when the extended set is disabled, addresses embed- ded in opcodes are treated as literal memory locations: either as a location in the access bank (a = 0 ) or in a gpr bank designated by the bsr (a = 1 ). when the extended instruction set is enabled and a = 0 , however, a file register argument of 5fh or less is interpreted as an offset from the pointer value in fsr2 and not as a literal address. for practical purposes, this means that all instructions that use the access ram bit as an argument C that is, all byte-oriented and bit-oriented instructions, or almost half of the core pic18 instruc- tions C may behave differently when the extended instruction set is enabled. when the content of fsr2 is 00h, the boundaries of the access ram are essentially remapped to their original values. this may be useful in creating backward compatible code. if this technique is used, it may be necessary to save the value of fsr2 and restore it when moving back and forth between c and assembly routines in order to preserve the stack pointer. users must also keep in mind the syntax requirements of the extended instruction set (see section 29.2.3.1 extended instruction syntax with standard pic18 commands ). although the indexed literal offset mode can be very useful for dynamic stack and pointer manipulation, it can also be very annoying if a simple arithmetic opera- tion is carried out on the wrong register. users who are accustomed to the pic18 programming must keep in mind, that when the extended instruction set is enabled, register addresses of 5fh or less are used for indexed literal offset addressing. representative examples of typical byte-oriented and bit-oriented instructions in the indexed literal offset mode are provided on the following page to show how execution is affected. the operand conditions shown in the examples are applicable to all instructions of these types. 29.2.3.1 extended instruction syntax with standard pic18 commands when the extended instruction set is enabled, the file register argument f in the standard byte-oriented and bit-oriented commands is replaced with the literal offset value k. as already noted, this occurs only when f is less than or equal to 5fh. when an offset value is used, it must be indicated by square brackets ([ ]). as with the extended instructions, the use of brackets indicates to the compiler that the value is to be interpreted as an index or an offset. omitting the brackets, or using a value greater than 5fh within the brackets, will generate an error in the mpasm? assembler. if the index argument is properly bracketed for indexed literal offset addressing, the access ram argument is never specified; it will automatically be assumed to be 0 . this is in contrast to standard operation (extended instruction set disabled), when a is set on the basis of the target address. declaring the access ram bit in this mode will also generate an error in the mpasm assembler. the destination argument, d, functions as before. in the latest versions of the mpasm assembler, language support for the extended instruction set must be explicitly invoked. this is done with either the command line option, /y , or the pe directive in the source listing. 29.2.4 considerations when enabling the extended instruction set it is important to note that the extensions to the instruc- tion set may not be beneficial to all users. in particular, users who are not writing code that uses a software stack may not benefit from using the extensions to the instruction set. additionally, the indexed literal offset addressing mode may create issues with legacy applications written to the pic18 assembler. this is because instructions in the legacy code may attempt to address registers in the access bank below 5fh. since these addresses are interpreted as literal offsets to fsr2 when the instruction set extension is enabled, the application may read or write to the wrong data addresses. when porting an application to the pic18f87k22 family, it is very important to consider the type of code. a large, re-entrant application that is written in c and would benefit from efficient compilation will do well when using the instruction set extensions. legacy applications that heavily use the access bank will most likely not benefit from using the extended instruction set. note: enabling the pic18 instruction set exten- sion may cause legacy applications to behave erratically or fail entirely. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 479 pic18f87k22 family addwf add w to indexed (indexed literal offset mode) syntax: addwf [k] {,d} operands: 0 ? k ? 95 d ? [0,1] operation: (w) + ((fsr2) + k) ? dest status affected: n, ov, c, dc, z encoding: 0010 01d0 kkkk kkkk description: the contents of w are added to the contents of the register indicated by fsr2, offset by the value k. if d is 0 , the result is stored in w. if d is 1 , the result is stored back in register f. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read k process data write to destination example: addwf [ofst] ,0 before instruction w = 17h ofst = 2ch fsr2 = 0a00h contents of 0a2ch = 20h after instruction w = 37h contents of 0a2ch = 20h bsf bit set indexed (indexed literal offset mode) syntax: bsf [k], b operands: 0 ? f ? 95 0 ? b ? 7 operation: 1 ? ((fsr2) + k) status affected: none encoding: 1000 bbb0 kkkk kkkk description: bit b of the register indicated by fsr2, offset by the value k, is set. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read register f process data write to destination example: bsf [flag_ofst], 7 before instruction flag_ofst = 0ah fsr2 = 0a00h contents of 0a0ah = 55h after instruction contents of 0a0ah = d5h setf set indexed (indexed literal offset mode) syntax: setf [k] operands: 0 ? k ? 95 operation: ffh ? ((fsr2) + k) status affected: none encoding: 0110 1000 kkkk kkkk description: the contents of the register indicated by fsr2, offset by k, are set to ffh. words: 1 cycles: 1 q cycle activity: q1 q2 q3 q4 decode read k process data write register example: setf [ofst] before instruction ofst = 2ch fsr2 = 0a00h contents of 0a2ch = 00h after instruction contents of 0a2ch = ffh downloaded from: http:///
pic18f87k22 family ds39960d-page 480 ? 2009-2011 microchip technology inc. 29.2.5 special considerations with microchip mplab ? ide tools the latest versions of microchips software tools have been designed to fully support the extended instruction set for the pic18f87k22 family. this includes the mplab c18 c compiler, mpasm assembly language and mplab integrated development environment (ide). when selecting a target device for software development, mplab ide will automatically set default configuration bits for that device. the default setting for the xinst configuration bit is 0 , disabling the extended instruction set and indexed literal offset addressing. for proper execution of applications developed to take advantage of the extended instruction set, xinst must be set during programming. to develop software for the extended instruction set, the user must enable support for the instructions and the indexed addressing mode in their language tool(s). depending on the environment being used, this may be done in several ways: a menu option or dialog box within the environment that allows the user to configure the language tool and its settings for the project a command line option a directive in the source code these options vary between different compilers, assemblers and development environments. users are encouraged to review the documentation accompany- ing their development systems for the appropriate information. downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 481 pic18f87k22 family 30.0 development support the pic ? microcontrollers and dspic ? digital signal controllers are supported with a full range of software and hardware development tools: integrated development environment - mplab ? ide software compilers/assemblers/linkers - mplab c compiler for various device families - hi-tech c for various device families - mpasm tm assembler -mplink tm object linker/ mplib tm object librarian - mplab assembler/linker/librarian for various device families simulators - mplab sim software simulator emulators - mplab real ice? in-circuit emulator in-circuit debuggers - mplab icd 3 - pickit? 3 debug express device programmers - pickit? 2 programmer - mplab pm3 device programmer low-cost demonstration/development boards, evaluation kits, and starter kits 30.1 mplab integrated development environment software the mplab ide software brings an ease of software development previously unseen in the 8/16/32-bit microcontroller market. the mplab ide is a windows ? operating system-based application that contains: a single graphical interface to all debugging tools - simulator - programmer (sold separately) - in-circuit emulator (sold separately) - in-circuit debugger (sold separately) a full-featured editor with color-coded context a multiple project manager customizable data windows with direct edit of contents high-level source code debugging mouse over variable inspection drag and drop variables from source to watch windows extensive on-line help integration of select third party tools, such as iar c compilers the mplab ide allows you to: edit your source files (either c or assembly) one-touch compile or assemble, and download to emulator and simulator tools (automatically updates all project information) debug using: - source files (c or assembly) - mixed c and assembly - machine code mplab ide supports multiple debugging tools in a single development paradigm, from the cost-effective simulators, through low-cost in-circuit debuggers, to full-featured emulators. this eliminates the learning curve when upgrading to tools with increased flexibility and power. downloaded from: http:///
pic18f87k22 family ds39960d-page 482 ? 2009-2011 microchip technology inc. 30.2 mplab c compilers for various device families the mplab c compiler code development systems are complete ansi c compilers for microchips pic18, pic24 and pic32 families of microcontrollers and the dspic30 and dspic33 families of digital signal control- lers. these compilers provide powerful integration capabilities, superior code optimization and ease of use. for easy source level debugging, the compilers provide symbol information that is optimized to the mplab ide debugger. 30.3 hi-tech c for various device families the hi-tech c compiler code development systems are complete ansi c compilers for microchips pic family of microcontrollers and the dspic family of digital signal controllers. these compilers provide powerful integration capabilities, omniscient code generation and ease of use. for easy source level debugging, the compilers provide symbol information that is optimized to the mplab ide debugger. the compilers include a macro assembler, linker, pre- processor, and one-step driver, and can run on multiple platforms. 30.4 mpasm assembler the mpasm assembler is a full-featured, universal macro assembler for pic10/12/16/18 mcus. the mpasm assembler generates relocatable object files for the mplink object linker, intel ? standard hex files, map files to detail memory usage and symbol reference, absolute lst files that contain source lines and generated machine code and coff files for debugging. the mpasm assembler features include: integration into mplab ide projects user-defined macros to streamline assembly code conditional assembly for multi-purpose source files directives that allow complete control over the assembly process 30.5 mplink object linker/ mplib object librarian the mplink object linker combines relocatable objects created by the mpasm assembler and the mplab c18 c compiler. it can link relocatable objects from precompiled libraries, using directives from a linker script. the mplib object librarian manages the creation and modification of library files of precompiled code. when a routine from a library is called from a source file, only the modules that contain that routine will be linked in with the application. this allows large libraries to be used efficiently in many different applications. the object linker/library features include: efficient linking of single libraries instead of many smaller files enhanced code maintainability by grouping related modules together flexible creation of libraries with easy module listing, replacement, deletion and extraction 30.6 mplab assembler, linker and librarian for various device families mplab assembler produces relocatable machine code from symbolic assembly language for pic24, pic32 and dspic devices. mplab c compiler uses the assembler to produce its object file. the assembler generates relocatable object files that can then be archived or linked with other relocatable object files and archives to create an executable file. notable features of the assembler include: support for the entire device instruction set support for fixed-point and floating-point data command line interface rich directive set flexible macro language mplab ide compatibility downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 483 pic18f87k22 family 30.7 mplab sim software simulator the mplab sim software simulator allows code development in a pc-hosted environment by simulat- ing the pic mcus and dspic ? dscs on an instruction level. on any given instruction, the data areas can be examined or modified and stimuli can be applied from a comprehensive stimulus controller. registers can be logged to files for further run-time analysis. the trace buffer and logic analyzer display extend the power of the simulator to record and track program execution, actions on i/o, most peripherals and internal registers. the mplab sim software simulator fully supports symbolic debugging using the mplab c compilers, and the mpasm and mplab assemblers. the soft- ware simulator offers the flexibility to develop and debug code outside of the hardware laboratory envi- ronment, making it an excellent, economical software development tool. 30.8 mplab real ice in-circuit emulator system mplab real ice in-circuit emulator system is microchips next generation high-speed emulator for microchip flash dsc and mcu devices. it debugs and programs pic ? flash mcus and dspic ? flash dscs with the easy-to-use, powerful graphical user interface of the mplab integrated development environment (ide), included with each kit. the emulator is connected to the design engineers pc using a high-speed usb 2.0 interface and is connected to the target with either a connector compatible with in- circuit debugger systems (rj11) or with the new high- speed, noise tolerant, low-voltage differential signal (lvds) interconnection (cat5). the emulator is field upgradable through future firmware downloads in mplab ide. in upcoming releases of mplab ide, new devices will be supported, and new features will be added. mplab real ice offers significant advantages over competitive emulators including low-cost, full-speed emulation, run-time variable watches, trace analysis, complex breakpoints, a ruggedized probe interface and long (up to three meters) interconnection cables. 30.9 mplab icd 3 in-circuit debugger system mplab icd 3 in-circuit debugger system is micro- chips most cost effective high-speed hardware debugger/programmer for microchip flash digital sig- nal controller (dsc) and microcontroller (mcu) devices. it debugs and programs pic ? flash microcon- trollers and dspic ? dscs with the powerful, yet easy- to-use graphical user interface of mplab integrated development environment (ide). the mplab icd 3 in-circuit debugger probe is con- nected to the design engineers pc using a high-speed usb 2.0 interface and is connected to the target with a connector compatible with the mplab icd 2 or mplab real ice systems (rj-11). mplab icd 3 supports all mplab icd 2 headers. 30.10 pickit 3 in-circuit debugger/ programmer and pickit 3 debug express the mplab pickit 3 allows debugging and program- ming of pic ? and dspic ? flash microcontrollers at a most affordable price point using the powerful graphical user interface of the mplab integrated development environment (ide). the mplab pickit 3 is connected to the design engineers pc using a full speed usb interface and can be connected to the target via an microchip debug (rj-11) connector (compatible with mplab icd 3 and mplab real ice). the connector uses two device i/o pins and the reset line to imple- ment in-circuit debugging and in-circuit serial pro- gramming?. the pickit 3 debug express include the pickit 3, demo board and microcontroller, hookup cables and cdrom with users guide, lessons, tutorial, compiler and mplab ide software. downloaded from: http:///
pic18f87k22 family ds39960d-page 484 ? 2009-2011 microchip technology inc. 30.11 pickit 2 development programmer/debugger and pickit 2 debug express the pickit? 2 development programmer/debugger is a low-cost development tool with an easy to use inter- face for programming and debugging microchips flash families of microcontrollers. the full featured windows ? programming interface supports baseline (pic10f, pic12f5xx, pic16f5xx), midrange (pic12f6xx, pic16f), pic18f, pic24, dspic30, dspic33, and pic32 families of 8-bit, 16-bit, and 32-bit microcontrollers, and many microchip serial eeprom products. with microchips powerful mplab integrated development environment (ide) the pickit? 2 enables in-circuit debugging on most pic ? microcon- trollers. in-circuit-debugging runs, halts and single steps the program while the pic microcontroller is embedded in the application. when halted at a break- point, the file registers can be examined and modified. the pickit 2 debug express include the pickit 2, demo board and microcontroller, hookup cables and cdrom with users guide, lessons, tutorial, compiler and mplab ide software. 30.12 mplab pm3 device programmer the mplab pm3 device programmer is a universal, ce compliant device programmer with programmable voltage verification at v ddmin and v ddmax for maximum reliability. it features a large lcd display (128 x 64) for menus and error messages and a modu- lar, detachable socket assembly to support various package types. the icsp? cable assembly is included as a standard item. in stand-alone mode, the mplab pm3 device programmer can read, verify and program pic devices without a pc connection. it can also set code protection in this mode. the mplab pm3 connects to the host pc via an rs-232 or usb cable. the mplab pm3 has high-speed communications and optimized algorithms for quick programming of large memory devices and incorporates an mmc card for file storage and data applications. 30.13 demonstration/development boards, evaluation kits, and starter kits a wide variety of demonstration, development and evaluation boards for various pic mcus and dspic dscs allows quick application development on fully func- tional systems. most boards include prototyping areas for adding custom circuitry and provide application firmware and source code for examination and modification. the boards support a variety of features, including leds, temperature sensors, switches, speakers, rs-232 interfaces, lcd displays, potentiometers and additional eeprom memory. the demonstration and development boards can be used in teaching environments, for prototyping custom circuits and for learning about various microcontroller applications. in addition to the picdem? and dspicdem? demon- stration/development board series of circuits, microchip has a line of evaluation kits and demonstration software for analog filter design, k ee l oq ? security ics, can, irda ? , powersmart battery management, seeval ? evaluation system, sigma-delta adc, flow rate sensing, plus many more. also available are starter kits that contain everything needed to experience the specified device. this usually includes a single application and debug capability, all on one board. check the microchip web page ( www.microchip.com ) for the complete list of demonstration, development and evaluation kits. downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 485 pic18f87k22 family 31.0 electrical characteristics absolute maximum ratings (?) ambient temperature under bias................................................................................................. ............-40c to +125c storage temperature ............................................................................................................ .................. -65c to +150c voltage on any digital only i/o pin with respect to v ss (except v dd )........................................................... -0.3v to 7.5v voltage on mclr with respect to v ss ........................................................................................................... 0.3v to 9.0v voltage on any combined digital and analog pin with respect to v ss (except v dd and mclr )...... -0.3v to (v dd + 0.3v) voltage on v dd with respect to v ss (with regulator enabled) ..................................................................... -0.3v to 5.5v voltage on v dd with respect to v ss (with regulator disabled)..................................................................... -0.3v to 3.6v total power dissipation (note 1 ) ..................................................................................................................................1w maximum current out of v ss pin ........................................................................................................................... 300 ma maximum current into v dd pin ..............................................................................................................................250 ma input clamp current, i ik (v i < 0 or v i > v dd ) .......................................................................................................... 20 ma output clamp current, i ok (v o < 0 or v o > v dd ) ...................................................................................................20 ma maximum output current sunk by porta<7:6> and any portb and portc i/o pins.........................................25 ma maximum output current sunk by any portd, porte and portj i/o pins ..........................................................8 ma maximum output current sunk by porta<5:0> and any portf, portg and porth i/o pins ............................2 ma maximum output current sourced by porta<7:6> and any portb and portc i/o pins ...................................25 ma maximum output current sourced by any portd, porte and portj i/o pins .....................................................8 ma maximum output current sourced by porta<5:0> and any portf, portg and porth i/o pins .......................2 ma maximum current sunk by ? all ports combined.......................................................................................................200 ma note 1: power dissipation is calculated as follows: pdis = v dd x {i dd C ? i oh } + ? {(v dd C v oh ) x i oh } + ? (v ol x i ol ) ? notice: stresses above those listed under absolute maximum ratings may cause permanent damage to the device. this is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operation listings of this specification is not implied. exposure to maximum rating conditions for extended periods may affect device reliability. downloaded from: http:///
pic18f87k22 family ds39960d-page 486 ? 2011 microchip technology inc. figure 31-1: voltage-frequency graph, regulator enabled (industrial/extended) (1) figure 31-2: voltage-frequency graph, regulator disabled (industrial/extended) (1,2) frequency voltage (v dd ) 6v 1.8v 64 mhz (1) 5v4v 3v 5.5v 3v 0 4 mhz pic18f87k22 family (extended) note 1: f max = 25 mhz in 8-bit external memory mode. for v dd values, 1.8v to 3v, f max = (v dd C 1.72)/0.02 mhz. 2: f max = 64 mhz in all other modes. for v dd values, 1.8v to 3v, f max = (v dd C 1.72)/0.02 mhz. 48 mhz pic18f87k22 family (industrial only) frequency voltage (v dd ) 4v 1.8v 64 mhz 3.75v 3.25v 2.5v 3.6v 4 mhz 3v note 1: when the on-chip voltage regulator is disabled, v dd must be maintained so that v dd ?? 3.6v. 2: for v dd values, 1.8v to 3v, f max = (v dd C 1.72)/0.02 mhz. pic18f87k22 family (extended) 48 mhz pic18f87k22 family (industrial only) downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 487 pic18f87k22 family 31.1 dc characteristics: supply voltage pic18f87k22 family (industrial/extended) pic18f87k22 family (industrial/extended) standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. symbol characteristic min typ max units conditions d001 v dd supply voltage 1.81.8 3.65.5 vv envreg tied to v ss envreg tied to v dd d001c av dd analog supply voltage v dd C 0.3 v dd + 0.3 v d001d av ss analog ground potential v ss C 0.3 v ss + 0.3 v d002 v dr ram data retention voltage ( 1 ) 1.5 v d003 v por v dd start voltage to ensure internal power-on reset signal 0 . 7v s e e section 5.3 power-on reset (por) for details d004 s vdd v dd rise rate to ensure internal power-on reset signal 0.05 v/ms see section 5.3 power-on reset (por) for details d005 b vdd brown-out reset voltage (high/medium/ low-power mode) ( 2 ) borv<1:0> = 11 ( 3 ) borv<1:0> = 10 borv<1:0> = 01 borv<1:0> = 00 1.69 1.88 2.53 2.82 1.8 2.0 2.7 3.0 1.91 2.12 2.86 3.18 note 1: this is the limit to which v dd can be lowered in sleep mode, or during a device reset, without losing ram data. 2: the following values are taken in hp-bor mode. 3: the device will operate normally until brown-out reset occurs, even though v dd may be below v ddmin . downloaded from: http:///
pic18f87k22 family ds39960d-page 488 ? 2011 microchip technology inc. 31.2 dc characteristics: power-down and supply current pic18f87k22 family (industrial/extended) pic18f87k22 family (industrial/extended) standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device typ max units conditions power-down current (i pd ) ( 1 ) all devices 10 500 na -40c v dd = 1.8v ( 4 ) ( sleep mode) regulator disabled 20 500 na +25c 120 600 na +60c 630 1800 na +85c 4 9 a +125oc all devices 50 700 na -40c v dd = 3.3v ( 4 ) ( sleep mode) regulator disabled 60 700 na +25c 170 800 na +60c 700 2700 na +85c 5 11 a +125oc all devices 350 1300 na -40c v dd = 5v ( 5 ) ( sleep mode) regulator enabled 400 1400 na +25c 550 1500 na +60c 1350 4000 na +85c 6 12 a +125oc note 1: the power-down current in sleep mode does not depend on the oscillator type. power-down current is measured with the part in sleep mode, with all i/o pins in a high-impedance state and tied to v dd or v ss , and all features that add delta current are disabled (such as wdt, sosc oscillator, bor, etc.). 2: the supply current is mainly a function of operating voltage, frequency and mode. other factors, such as i/o pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also hav e an impact on the current consumption. the test conditions for all i dd measurements in active operation mode are: osc1 = external square wave, from rail-to-rail; all i/o pins tri-stated, pulled to v dd ; mclr = v dd ; wdt enabled/disabled as specified. 3: standard, low-cost 32 khz crystals have an operating temperature range of -10c to +70c. extended temperature crystals are available at a much higher cost. 4: voltage regulator disabled (envreg = 0 , tied to v ss , reten (config1l<0>) = 1 ). 5: voltage regulator enabled (envreg = 1 , tied to v dd , sreten (wdtcon<4>) = 1 and reten (config1l<0>) = 0 ). 6: 48 mhz, maximum frequency at +125oc. downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 489 pic18f87k22 family supply current (i dd ) (2,3) all devices 5.3 10 a -40c v dd = 1.8v ( 4 ) regulator disabled f osc = 31 khz ( rc_run mode, lf-intosc) 5.5 10 a +25c 5.5 10 a +85c 12 24 a +125oc all devices 10 15 a -40c v dd = 3.3v ( 4 ) regulator disabled 10 16 a +25c 11 17 a +85c 15 35 a +125oc all devices 70 180 a -40c v dd = 5v ( 5 ) regulator enabled 80 185 a +25c 90 190 a +85c 200 500 a +125oc all devices 410 850 a -40c v dd = 1.8v ( 4 ) regulator disabled f osc = 1 mhz ( rc_run mode, hf-intosc) 410 800 a +25c 410 830 a +85c 700 1500 a +125oc all devices 680 990 a -40c v dd = 3.3v ( 4 ) regulator disabled 680 960 a +25c 670 950 a +85c 800 1700 a +125oc all devices 760 1400 a -40c v dd = 5v ( 5 ) regulator enabled 780 1400 a +25c 800 1500 a +85c 1200 2400 a +125oc all devices 760 1300 a -40c v dd = 1.8v ( 4 ) regulator disabled f osc = 4 mhz ( rc_run mode, hf-intosc) 760 1400 a +25c 770 1500 a +85c 800 1700 a +125oc all devices 1.4 2.5 ma -40c v dd = 3.3v ( 4 ) regulator disabled 1.4 2.5 ma +25c 1.4 2.5 ma +85c 1.5 3.0 ma +125oc all devices 1.5 2.7 ma -40c v dd = 5v ( 5 ) regulator enabled 1.5 2.7 ma +25c 1.5 2.7 ma +85c 1.6 3.3 ma +125oc 31.2 dc characteristics: power-down and supply current pic18f87k22 family (industrial/extended) (continued) pic18f87k22 family (industrial/extended) standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device typ max units conditions note 1: the power-down current in sleep mode does not depend on the oscillator type. power-down current is measured with the part in sleep mode, with all i/o pins in a high-impedance state and tied to v dd or v ss , and all features that add delta current are disabled (such as wdt, sosc oscillator, bor, etc.). 2: the supply current is mainly a function of operating voltage, frequency and mode. other factors, such as i/o pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also hav e an impact on the current consumption. the test conditions for all i dd measurements in active operation mode are: osc1 = external square wave, from rail-to-rail; all i/o pins tri-stated, pulled to v dd ; mclr = v dd ; wdt enabled/disabled as specified. 3: standard, low-cost 32 khz crystals have an operating temperature range of -10c to +70c. extended temperature crystals are available at a much higher cost. 4: voltage regulator disabled (envreg = 0 , tied to v ss , reten (config1l<0>) = 1 ). 5: voltage regulator enabled (envreg = 1 , tied to v dd , sreten (wdtcon<4>) = 1 and reten (config1l<0>) = 0 ). 6: 48 mhz, maximum frequency at +125oc. downloaded from: http:///
pic18f87k22 family ds39960d-page 490 ? 2011 microchip technology inc. supply current (i dd ) cont. (2,3) all devices 2.1 5.5 a -40c v dd = 1.8v ( 4 ) regulator disabled f osc = 31 khz ( rc_idle mode, lf-intosc) 2.1 5.7 a +25c 2.2 6.0 a +85c 10 20 a +125oc all devices 3.7 7.5 a -40c v dd = 3.3v ( 4 ) regulator disabled 3.9 7.8 a +25c 3.9 8.5 a +85c 12 24 a +125oc all devices 70 180 a -40c v dd = 5v ( 5 ) regulator enabled 80 190 a +25c 80 200 a +85c 200 420 a +125oc all devices 330 650 a -40c v dd = 1.8v ( 4 ) regulator disabled f osc = 1 mhz ( rc_idle mode, hf-intosc) 330 640 a +25c 330 630 a +85c 500 850 a +125oc all devices 520 850 a -40c v dd = 3.3v ( 4 ) regulator disabled 520 900 a +25c 520 850 a +85c 800 1200 a +125oc all devices 590 940 a -40c v dd = 5v ( 5 ) regulator enabled 600 960 a +25c 620 990 a +85c 1000 1400 a +125oc all devices 470 770 a -40c v dd = 1.8v ( 4 ) regulator disabled f osc = 4 mhz ( rc_idle mode, internal hf-intosc) 470 770 a +25c 460 760 a +85c 700 1000 a +125oc all devices 800 1400 a -40c v dd = 3.3v ( 4 ) regulator disabled 800 1350 a +25c 790 1300 a +85c 1100 1400 a +125oc all devices 880 1600 a -40c v dd = 5v ( 5 ) regulator enabled 890 1700 a +25c 910 1800 a +85c 1200 2200 a +125oc 31.2 dc characteristics: power-down and supply current pic18f87k22 family (industrial/extended) (continued) pic18f87k22 family (industrial/extended) standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device typ max units conditions note 1: the power-down current in sleep mode does not depend on the oscillator type. power-down current is measured with the part in sleep mode, with all i/o pins in a high-impedance state and tied to v dd or v ss , and all features that add delta current are disabled (such as wdt, sosc oscillator, bor, etc.). 2: the supply current is mainly a function of operating voltage, frequency and mode. other factors, such as i/o pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also hav e an impact on the current consumption. the test conditions for all i dd measurements in active operation mode are: osc1 = external square wave, from rail-to-rail; all i/o pins tri-stated, pulled to v dd ; mclr = v dd ; wdt enabled/disabled as specified. 3: standard, low-cost 32 khz crystals have an operating temperature range of -10c to +70c. extended temperature crystals are available at a much higher cost. 4: voltage regulator disabled (envreg = 0 , tied to v ss , reten (config1l<0>) = 1 ). 5: voltage regulator enabled (envreg = 1 , tied to v dd , sreten (wdtcon<4>) = 1 and reten (config1l<0>) = 0 ). 6: 48 mhz, maximum frequency at +125oc. downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 491 pic18f87k22 family supply current (i dd ) cont. (2,3) all devices 130 390 a -40c v dd = 1.8v ( 4 ) regulator disabled f osc = 1 mh z ( pri_run mode, ec oscillator) 130 390 a +25c 130 390 a +85c 250 500 a +125oc all devices 270 790 a -40c v dd = 3.3v ( 4 ) regulator disabled 270 790 a +25c 270 790 a +85c 400 900 a +125oc all devices 430 990 a -40c v dd = 5v ( 5 ) regulator enabled 450 980 a +25c 460 980 a +85c 600 1300 a +125oc all devices 430 860 a -40c v dd = 1.8v ( 4 ) regulator disabled f osc = 4 mhz ( pri_run mode, ec oscillator) 530 900 a +25c 490 880 a +85c 750 1600 a +125oc all devices 850 1750 a -40c v dd = 3.3v ( 4 ) regulator disabled 850 1700 a +25c 850 1800 a +85c 1150 2400 a +125oc all devices 1.1 2.7 ma -40c v dd = 5v ( 5 ) regulator enabled 1.1 2.6 ma +25c 1.1 2.6 ma +85c 2.0 4.0 ma +125oc all devices 12 19 ma -40c v dd = 3.3v ( 4 ) regulator disabled f osc = 64 mh z ( pri_run mode, ec oscillator) 12 19 ma +25c 12 19 ma +85c 13 22 ma +125oc ( 6 ) all devices 13 20 ma -40c v dd = 5v ( 4 ) regulator enabled 13 20 ma +25c 13 20 ma +85c 14 23 ma +125oc ( 6 ) 31.2 dc characteristics: power-down and supply current pic18f87k22 family (industrial/extended) (continued) pic18f87k22 family (industrial/extended) standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device typ max units conditions note 1: the power-down current in sleep mode does not depend on the oscillator type. power-down current is measured with the part in sleep mode, with all i/o pins in a high-impedance state and tied to v dd or v ss , and all features that add delta current are disabled (such as wdt, sosc oscillator, bor, etc.). 2: the supply current is mainly a function of operating voltage, frequency and mode. other factors, such as i/o pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also hav e an impact on the current consumption. the test conditions for all i dd measurements in active operation mode are: osc1 = external square wave, from rail-to-rail; all i/o pins tri-stated, pulled to v dd ; mclr = v dd ; wdt enabled/disabled as specified. 3: standard, low-cost 32 khz crystals have an operating temperature range of -10c to +70c. extended temperature crystals are available at a much higher cost. 4: voltage regulator disabled (envreg = 0 , tied to v ss , reten (config1l<0>) = 1 ). 5: voltage regulator enabled (envreg = 1 , tied to v dd , sreten (wdtcon<4>) = 1 and reten (config1l<0>) = 0 ). 6: 48 mhz, maximum frequency at +125oc. downloaded from: http:///
pic18f87k22 family ds39960d-page 492 ? 2011 microchip technology inc. supply current (i dd ) cont. (2,3) all devices 3.3 5.6 ma -40c v dd = 3.3v ( 4 ) regulator disabled f osc = 16 mh z , ( pri_run mode, 4 mhz ec oscillator with pll) 3.3 5.5 ma +25c 3.3 5.5 ma +85c 3.6 6.0 ma +125oc all devices 3.5 5.9 ma -40c v dd = 5v ( 5 ) regulator enabled 3.5 5.8 ma +25c 3.5 5.8 ma +85c 3.8 7.0 ma +125oc all devices 12 18 ma -40c v dd = 3.3v ( 4 ) regulator disabled f osc = 64 mh z , ( pri_run mode, 16 mhz ec oscillator with pll) 12 18 ma +25c 12 18 ma +85c 13 22 ma +125oc ( 6 ) all devices 13 20 ma -40c v dd = 5v ( 5 ) regulator enabled 13 20 ma +25c 13 20 ma +85c 14 24 ma +125oc ( 6 ) 31.2 dc characteristics: power-down and supply current pic18f87k22 family (industrial/extended) (continued) pic18f87k22 family (industrial/extended) standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device typ max units conditions note 1: the power-down current in sleep mode does not depend on the oscillator type. power-down current is measured with the part in sleep mode, with all i/o pins in a high-impedance state and tied to v dd or v ss , and all features that add delta current are disabled (such as wdt, sosc oscillator, bor, etc.). 2: the supply current is mainly a function of operating voltage, frequency and mode. other factors, such as i/o pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also hav e an impact on the current consumption. the test conditions for all i dd measurements in active operation mode are: osc1 = external square wave, from rail-to-rail; all i/o pins tri-stated, pulled to v dd ; mclr = v dd ; wdt enabled/disabled as specified. 3: standard, low-cost 32 khz crystals have an operating temperature range of -10c to +70c. extended temperature crystals are available at a much higher cost. 4: voltage regulator disabled (envreg = 0 , tied to v ss , reten (config1l<0>) = 1 ). 5: voltage regulator enabled (envreg = 1 , tied to v dd , sreten (wdtcon<4>) = 1 and reten (config1l<0>) = 0 ). 6: 48 mhz, maximum frequency at +125oc. downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 493 pic18f87k22 family supply current (i dd ) cont. (2,3) all devices 42 73 a -40c v dd = 1.8v ( 4 ) regulator disabled f osc = 1 mhz ( pri_idle mode, ec oscillator) 42 73 a +25c 43 74 a +85c 53 100 a +125oc all devices 110 190 a -40c v dd = 3.3v ( 4 ) regulator disabled 110 195 a +25c 110 195 a +85c 130 250 a +125oc all devices 280 450 a -40c v dd = 5v ( 5 ) regulator enabled 290 440 a +25c 300 460 a +85c 330 500 a +125oc all devices 160 360 a -40c v dd = 1.8v ( 4 ) regulator disabled f osc = 4 mhz ( pri_idle mode, ec oscillator) 160 360 a +25c 170 370 a +85c 200 400 a +125oc all devices 330 650 a -40c v dd = 3.3v ( 4 ) regulator disabled 340 660 a +25c 340 660 a +85c 370 700 a +125oc all devices 510 900 a -40c v dd = 5v ( 5 ) regulator enabled 520 950 a +25c 540 990 a +85c 600 1200 a +125oc all devices 4.7 9 ma -40c v dd = 3.3v ( 4 ) regulator disabled f osc = 64 mhz ( pri_idle mode, ec oscillator) 4.8 9 ma +25c 4.8 10 ma +85c 5.2 12 ma +125oc ( 6 ) all devices 5.1 11 ma -40c v dd = 5v ( 5 ) regulator enabled 5.1 11 ma +25c 5.2 12 ma +85c 5.7 14 ma +125oc ( 6 ) 31.2 dc characteristics: power-down and supply current pic18f87k22 family (industrial/extended) (continued) pic18f87k22 family (industrial/extended) standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device typ max units conditions note 1: the power-down current in sleep mode does not depend on the oscillator type. power-down current is measured with the part in sleep mode, with all i/o pins in a high-impedance state and tied to v dd or v ss , and all features that add delta current are disabled (such as wdt, sosc oscillator, bor, etc.). 2: the supply current is mainly a function of operating voltage, frequency and mode. other factors, such as i/o pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also hav e an impact on the current consumption. the test conditions for all i dd measurements in active operation mode are: osc1 = external square wave, from rail-to-rail; all i/o pins tri-stated, pulled to v dd ; mclr = v dd ; wdt enabled/disabled as specified. 3: standard, low-cost 32 khz crystals have an operating temperature range of -10c to +70c. extended temperature crystals are available at a much higher cost. 4: voltage regulator disabled (envreg = 0 , tied to v ss , reten (config1l<0>) = 1 ). 5: voltage regulator enabled (envreg = 1 , tied to v dd , sreten (wdtcon<4>) = 1 and reten (config1l<0>) = 0 ). 6: 48 mhz, maximum frequency at +125oc. downloaded from: http:///
pic18f87k22 family ds39960d-page 494 ? 2011 microchip technology inc. supply current (i dd ) cont. (2,3) all devices 3.7 8.5 a -40c v dd = 1.8v ( 4 ) regulator disabled f osc = 32 khz ( 3 ) ( sec_run mode, soscsel = 01 ) 5.4 10 a +25c 6.6 13 a +85c 13 30 a +125oc all devices 8.7 18 a -40c v dd = 3.3v ( 4 ) regulator disabled 10 20 a +25c 12 23 a +85c 25 60 a +125oc all devices 60 160 a -40c v dd = 5v ( 4 ) regulator enabled 90 190 a +25c 100 240 a +85c 200 450 a +125oc all devices 1.2 4 a -40c v dd = 1.8v ( 4 ) regulator disabled f osc = 32 khz ( 3 ) ( sec_idle mode, soscsel = 01 ) 1.7 5 a +25c 2.6 6 a +85c 9 20 a +125oc all devices 1.6 7 a -40c v dd = 3.3v ( 4 ) regulator disabled 2.8 9 a +25c 4.1 10 a +85c 17 40 a +125oc all devices 60 150 a -40c v dd = 5v ( 5 ) regulator enabled 80 180 a +25c 100 240 a +85c 180 440 a +125oc 31.2 dc characteristics: power-down and supply current pic18f87k22 family (industrial/extended) (continued) pic18f87k22 family (industrial/extended) standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device typ max units conditions note 1: the power-down current in sleep mode does not depend on the oscillator type. power-down current is measured with the part in sleep mode, with all i/o pins in a high-impedance state and tied to v dd or v ss , and all features that add delta current are disabled (such as wdt, sosc oscillator, bor, etc.). 2: the supply current is mainly a function of operating voltage, frequency and mode. other factors, such as i/o pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also hav e an impact on the current consumption. the test conditions for all i dd measurements in active operation mode are: osc1 = external square wave, from rail-to-rail; all i/o pins tri-stated, pulled to v dd ; mclr = v dd ; wdt enabled/disabled as specified. 3: standard, low-cost 32 khz crystals have an operating temperature range of -10c to +70c. extended temperature crystals are available at a much higher cost. 4: voltage regulator disabled (envreg = 0 , tied to v ss , reten (config1l<0>) = 1 ). 5: voltage regulator enabled (envreg = 1 , tied to v dd , sreten (wdtcon<4>) = 1 and reten (config1l<0>) = 0 ). 6: 48 mhz, maximum frequency at +125oc. downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 495 pic18f87k22 family d022 ( ? i wdt ) d022( ? i wdt ) module differential currents ( ? i wdt , ? i bor , ? i hlvd , ? i oscb , ? i ad ) watchdog timer all devices 0.3 1 a -40c v dd = 1.8v ( 4 ) regulator disabled 0.3 1 a +25c 0.3 1 a +85c 0.5 2 a +125oc all devices 0.6 2 a -40c v dd = 3.3v ( 4 ) regulator disabled 0.6 2 a +25c 0.7 2 a +85c 1 3 a +125oc all devices 0.6 2 a -40c v dd = 5v ( 5 ) regulator enabled 0.6 2 a +25c 0.7 2 a +85c 1.5 4 a +125oc d022a ( ? i bor ) ( ? i bor ) brown-out reset all devices 4.6 19 a -40c v dd = 3.3v ( 4 ) regulator disabled high-power bor 4.5 20 a +25c 4.7 20 a +85c 18 40 a +125oc all devices 4.2 20 a -40c v dd = 5v ( 5 ) regulator enabled high-power bor 4.3 20 a +25c 4.4 20 a +85c 20 40 a +125oc d022b ( ? i hlvd ) high/low-voltage detect all devices 3.8 9 a -40c v dd = 1.8v ( 4 ) regulator disabled 4.2 9 a +25c 4.3 10 a +85c 4.5 12 a +125oc all devices 4.5 11 a -40c v dd = 3.3v ( 4 ) regulator disabled 4.8 12 a +25c 4.8 12 a +85c 5.0 14 a +125oc all devices 4.9 13 a -40c v dd = 5v ( 5 ) regulator enabled 4.9 13 a +25c 4.9 13 a +85c 5.3 15 a +125oc 31.2 dc characteristics: power-down and supply current pic18f87k22 family (industrial/extended) (continued) pic18f87k22 family (industrial/extended) standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device typ max units conditions note 1: the power-down current in sleep mode does not depend on the oscillator type. power-down current is measured with the part in sleep mode, with all i/o pins in a high-impedance state and tied to v dd or v ss , and all features that add delta current are disabled (such as wdt, sosc oscillator, bor, etc.). 2: the supply current is mainly a function of operating voltage, frequency and mode. other factors, such as i/o pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also hav e an impact on the current consumption. the test conditions for all i dd measurements in active operation mode are: osc1 = external square wave, from rail-to-rail; all i/o pins tri-stated, pulled to v dd ; mclr = v dd ; wdt enabled/disabled as specified. 3: standard, low-cost 32 khz crystals have an operating temperature range of -10c to +70c. extended temperature crystals are available at a much higher cost. 4: voltage regulator disabled (envreg = 0 , tied to v ss , reten (config1l<0>) = 1 ). 5: voltage regulator enabled (envreg = 1 , tied to v dd , sreten (wdtcon<4>) = 1 and reten (config1l<0>) = 0 ). 6: 48 mhz, maximum frequency at +125oc. downloaded from: http:///
pic18f87k22 family ds39960d-page 496 ? 2011 microchip technology inc. d025 ( ? i rtcc ) real-time clock/calendar with sosc oscillator all devices 0.7 2.7 a -40c v dd = 1.8v ( 4 ) regulator disabled 32.768 khz, soscrun = 1 0.7 2.8 a +25c 1.1 2.8 a +60c 1.1 +85c 2.9 a 2.2 4.4 a +125oc all devices 1.2 2.9 a -40c v dd = 3.3v ( 4 ) regulator disabled 1.1 2.8 a +25c 2 4.6 a +60c 2 4.8 a +85c 4 6.5 a +125oc all devices 1.5 4.4 a -40c v dd = 5v ( 5 ) regulator enabled 1.5 4.4 a +25c 1.7 4.7 a +60c 1.7 4.7 a +85c 3.5 6.9 a +125oc 31.2 dc characteristics: power-down and supply current pic18f87k22 family (industrial/extended) (continued) pic18f87k22 family (industrial/extended) standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device typ max units conditions note 1: the power-down current in sleep mode does not depend on the oscillator type. power-down current is measured with the part in sleep mode, with all i/o pins in a high-impedance state and tied to v dd or v ss , and all features that add delta current are disabled (such as wdt, sosc oscillator, bor, etc.). 2: the supply current is mainly a function of operating voltage, frequency and mode. other factors, such as i/o pin loading and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also hav e an impact on the current consumption. the test conditions for all i dd measurements in active operation mode are: osc1 = external square wave, from rail-to-rail; all i/o pins tri-stated, pulled to v dd ; mclr = v dd ; wdt enabled/disabled as specified. 3: standard, low-cost 32 khz crystals have an operating temperature range of -10c to +70c. extended temperature crystals are available at a much higher cost. 4: voltage regulator disabled (envreg = 0 , tied to v ss , reten (config1l<0>) = 1 ). 5: voltage regulator enabled (envreg = 1 , tied to v dd , sreten (wdtcon<4>) = 1 and reten (config1l<0>) = 0 ). 6: 48 mhz, maximum frequency at +125oc. downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 497 pic18f87k22 family 31.3 dc characteristics: pic18f87k22 family (industrial/extended) dc characteristics standard operating conditions (unless otherwise stated) operating temperature -40c ?? t a ? +85c for industrial -40c ?? t a ? +125c for extended param no. symbol characteristic min max units conditions v il input low voltage all i/o ports: d030 with ttl buffer v ss 0.15 v dd vv dd < 4.5v d031 with schmitt trigger buffer rc3, rc4 rd5, rd6 v ss v ss 0.8 0.2 v dd 1.5 vv v 4.5v ? v dd ?? 5.5v v dd < 4.5 4.5v ? v dd ?? 5.5v d031a rc3, rc4 v ss 0.3 v dd vi 2 c? enabled d031b rd5, rd6 v ss 0.8 v smbus enabled d032 mclr v ss 0.2 v dd v d033 osc1 v ss 0.2 v dd v lp, xt, hs modes d033a d034 osc1 sosci v ss v ss 0.2 v dd 0.3 v dd vv ec modes v ih input high voltage i/o ports with analog functions: d040 with ttl buffer 0.25 v dd 2.0 v dd v dd vv v dd < 4.5v 4.5v ? v dd ?? 5.5v d041 with schmitt trigger buffer rc3, rc4 rd5, rd6 0.8 0.7 v dd 3v v dd v dd 5.5 vv v v dd < 4.5v v dd < 4.5v 4.5v ? v dd ?? 5.5v d041a rc3, rc4 0.7 v dd v dd vi 2 c enabled d041b rd5, rd6 2.1 v dd v smbus enabled d042 mclr 0.8 v dd v dd v d043 osc1 0.9 v dd v dd v rc mode d043a d044 osc1 sosci 0.7 v dd 0.7 v dd v dd v dd vv hs mode i il input leakage current ( 1 ) d060 i/o ports 50 200 na v ss ?? v pin ?? v dd , pin at high-impedance d061 mclr 5 ? avss ?? v pin ?? v dd , +85c d063 osc1 5 ? avss ?? v pin ?? v dd i pu weak pull-up current d070 i purb portb weak pull-up current 50 400 ? av dd = 3.3v, v pin = v ss note 1: negative current is defined as current sourced by the pin. downloaded from: http:///
pic18f87k22 family ds39960d-page 498 ? 2011 microchip technology inc. 31.4 dc characteristics: ctmu current source specifications v ol output low voltage d080 i/o ports: porta, portb, portc 0.6 v i ol = 8.5 ma, v dd = 4.5v, -40 ? c to +125 ? c portd, porte, portf, portg, porth, portj 0 . 6v i ol = 3.5 ma, v dd = 4.5v, -40 ? c to +125 ? c d083 osc2/clko (ec modes) 0.6 v i ol = 1.6 ma. v dd = 5.5v, -40 ? c to +125 ? c v oh output high voltage ( 1 ) d090 i/o ports: v porta, portb, portc v dd C 0.7 v i oh = -3 ma, v dd = 4.5v, -40 ? c to +125 ? c portd, porte, portf, portg, porth, portj v dd C 0.7 v i oh = -2 ma, v dd = 4.5v, -40 ? c to +125 ? c d092 osc2/clko (intosc, ec modes) v dd C 0.7 v i oh = -1 ma, v dd = 5.5v, -40 ? c to +125 ? c capacitive loading specs on output pins d100 cosc2 osc2 pin 20 pf in hs mode when external clock is used to drive osc1 d101 c io all i/o pins and osc2 50 pf to meet the ac timing specifications d102 c b sclx, sdax 400 pf i 2 c? specification dc characteristics standard operating conditions: 1.8v to 5.5v (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. sym characteristic min typ ( 1 ) max units conditions i out 1 ctmu current source, base range 550 na ctmuicon<1:0> = 01 i out 2 ctmu current source, 10x range 5 . 5 ? a ctmuicon<1:0> = 10 i out 3 ctmu current source, 100x range 5 5 ? a ctmuicon<1:0> = 11 note 1: nominal value at center point of current trim range (ctmuicon<7:2> = 000000 ). 31.3 dc characteristics: pic18f87k22 family (industrial/extended) (continued) dc characteristics standard operating conditions (unless otherwise stated) operating temperature -40c ?? t a ? +85c for industrial -40c ?? t a ? +125c for extended param no. symbol characteristic min max units conditions note 1: negative current is defined as current sourced by the pin. downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 499 pic18f87k22 family table 31-1: memory programming requirements dc characteristics standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. sym characteristic min typ? max units conditions internal program memory programming specifications ( 1 ) d110 v pp voltage on mclr /v pp /re5 pin v dd + 1.5 10 v (note 3 , note 4 ) d113 i ddp supply current during programming 1 0m a data eeprom memory (note 2 ) d120 e d byte endurance 100k e/w -40 ? c to +125 ? c d121 v drw v dd for read/write 1.8 5.5 v using eecon to read/ write, envreg tied to v dd 1.8 3.6 v using eecon to read/ write, envreg tied to v ss d122 t dew erase/write cycle time 4 ms d123 t retd characteristic retention 40 year provided no other specifications are violated d124 t ref number of total erase/write cycles before refresh ( 2 ) 1m 10m e/w -40c to +125c program flash memory d130 e p cell endurance 10k e/w -40 ? c to +125 ? c d131 v pr v dd for read 1.8 5.5 v envreg tied to v dd 1.8 3.6 v envreg tied to v ss d132b v pew voltage for self-timed erase or write operations v dd 1.8 5.5 v envreg tied to v dd d133a t iw self-timed write cycle time 2 ms d134 t retd characteristic retention 40 year provided no other specifications are violated d135 i ddp supply current during programming 1 0m a d140 t we writes per erase cycle 1 for each physical address ? data in typ column is at 3.3v, 25c unless otherwise stated. these parameters are for design guidance only and are not tested. note 1: these specifications are for programming the on-chip program memory through the use of table write instructions. 2: refer to section 9.8 using the data eeprom for a more detailed discussion on data eeprom endurance. 3: required only if single-supply programming is disabled. 4: the mplab ? icd 2 does not support variable v pp output. circuitry to limit the mplab icd 2 v pp voltage must be placed between the mplab icd 2 and the target system when programming or debugging with the mplab icd 2. downloaded from: http:///
pic18f87k22 family ds39960d-page 500 ? 2011 microchip technology inc. table 31-2: comparator specifications table 31-3: voltage reference specifications table 31-4: internal voltage regulator specifications operating conditions: 1.8v ? v dd ? 5v, -40c ? t a ? +125c (unless otherwise stated) param no. sym characteristics min typ max units comments d300 v ioff input offset voltage 5.0 40 mv d301 v icm input common mode voltage av dd C 1.5 v d302 cmrr common mode rejection ratio 55 db d303 t resp response time ( 1 ) 150 400 ns d304 t mc 2 ov comparator mode change to output valid* 1 0 ? s note 1: response time measured with one comparator input at (av dd C 1.5)/2, while the other input transitions from v ss to v dd . operating conditions: 1.8v ? v dd ? 5v, -40c ? t a ? +125c (unless otherwise stated) param no. sym characteristics min typ max units comments d310 v res resolution v dd /32 l s b d311 vr aa absolute accuracy 1/2 lsb d312 vr ur unit resistor value (r) 2k ? d313 t set settling time ( 1 ) 10 ? s note 1: settling time measured while cvrr = 1 and cvr<3:0> transitions from 0000 to 1111 . operating conditions: -40c ? t a ? +125c (unless otherwise stated) param no. sym characteristics min typ max units comments v rgout regulator output voltage 3.3 v c efc external filter capacitor value 4.7 10 ? f capacitor must be low-esr, a low series resistance (< 5 ? ) downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 501 pic18f87k22 family 31.5 ac (timing) characteristics 31.5.1 timing parameter symbology the timing parameter symbols have been created following one of the following formats: 1. tpps2pps 3. t cc : st (i 2 c specifications only) 2. tpps 4. ts (i 2 c specifications only) t f frequency t time lowercase letters (pp) and their meanings: pp cc ccp1 osc osc1 ck clko rd rd cs cs rw rd or wr di sdi sc sck do sdo ss ss dt data in t0 t0cki io i/o port t1 t1cki mc mclr wr wr uppercase letters and their meanings: s f fall p period hh i g h rr i s e i invalid (high-impedance) v valid l low z high-impedance i 2 c only aa output access high high buf bus free low low t cc : st (i 2 c specifications only) cc hd hold su setup st dat data input hold sto stop condition sta start condition downloaded from: http:///
pic18f87k22 family ds39960d-page 502 ? 2011 microchip technology inc. 31.5.2 timing conditions the temperature and voltages specified in tab l e 3 1- 5 apply to all timing specifications unless otherwise noted. figure 31-3 specifies the load conditions for the timing specifications. table 31-5: temperature and voltage specifications C ac figure 31-3: load conditions for de vice timing specifications ac characteristics standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ?? +85c for industrial -40c ? t a ?? +125c for extended operating voltage v dd range as described in section 31.1 and section 31.3 . v dd /2 c l r l pin pin v ss v ss c l r l =464 ? c l = 50 pf for all pins except osc2/clko/ra6 and including d and e outputs as ports c l = 15 pf for osc2/clko/ra6 load condition 1 load condition 2 downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 503 pic18f87k22 family 31.5.3 timing diagrams and specifications figure 31-4: external clock timing table 31-6: external clock timing requirements param. no. symbol characteristic min max units conditions 1a f osc external clkin frequency ( 1 ) dc 64 mhz ec, ecio oscillator mode -40c ta +85c dc 48 mhz -40c ta +125c oscillator frequency ( 1 ) dc 4 mhz rc oscillator mode 0.1 4 mhz xt oscillator mode 4 16 mhz hs oscillator mode 4 16 mhz hs + pll oscillator mode 5 33 khz lp oscillator mode 1t osc external clkin period ( 1 ) 15.6 ns ec, ecio oscillator mode oscillator period ( 1 ) 250 ns rc oscillator mode 250 10,000 ns xt oscillator mode 40 62.5 250 250 nsns hs oscillator mode hs + pll oscillator mode 52 0 0 ? s lp oscillator mode 2t cy instruction cycle time ( 1 ) 62.5 ns t cy = 4/f osc 3t os l, t os h external clock in (osc1) high or low time 30 ns xt oscillator mode 2.5 ? s lp oscillator mode 10 ns hs oscillator mode 4t os r, t os f external clock in (osc1) rise or fall time 20 ns xt oscillator mode 50 ns lp oscillator mode 7.5 ns hs oscillator mode note 1: instruction cycle period (t cy ) equals four times the input oscillator time base period for all configurations except pll. all specified values are based on characterization data for that particular oscillator type under standard operating conditions with the device executing code. exceeding these specified limits may result in an unstable oscillator operation and/or higher than expected current consumpti on. all devices are tested to operate at min. values with an external clock applied to the osc1/clkin pin. when an external clock input is used, the max. cycle time limit is dc (no clock) for all devices. osc1 clko q4 q1 q2 q3 q4 q1 1 2 3 3 4 4 downloaded from: http:///
pic18f87k22 family ds39960d-page 504 ? 2011 microchip technology inc. table 31-7: pll clock timing specifications (v dd = 1.8v to 5.5v) table 31-8: internal rc accuracy (intosc) param no. sym characteristic min typ? max units conditions f10 f osc oscillator frequency range 4 5 mhz v dd = 1.8-5.5v 41 6m h z v dd = 3.0-5.5v, -40c to +85c 41 2m h z v dd = 3.0-5.5v, -40c to +125c f11 f sys on-chip vco system frequency 16 20 mhz v dd = 1.8-5.5v 16 64 mhz v dd = 3.0-5.5v, -40c to +85c 16 48 mhz v dd = 3.0-5.5v, -40c to +125c f12 t rc pll start-up time (lock time) 2 ms f13 ? clk clkout stability (jitter) -2 +2 % ? data in typ column is at 3v, 25 ? c unless otherwise stated. these parameters are for design guidance only and are not tested. pic18f87k22 family standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +125c param no. min typ max units conditions oa1 hfintosc/mfintosc accuracy @ freq = 16 mhz, 8 mhz, 4 mhz, 2 mhz, 1 mhz, 500 khz, 250 khz ( 1 ) -2 2 % +25c v dd = 3.0-5.5v -5 5 % -5 5 % -40c to +85c v dd = 1.8-5.5v -10 10 % -40c to +125c v dd = 1.8-5.5v oa2 lfintosc accuracy @ freq = 31 khz -15 15 % -40c to +125c v dd = 1.8-5.5v note 1: frequency calibrated at 25c. osctune register can be used to compensate for temperature drift. downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 505 pic18f87k22 family figure 31-5: clko and i/o timing table 31-9: clko and i/o timing requirements param no. symbol characteristic min typ max units conditions 10 t os h2 ck losc1 ? to clko ? 7 52 0 0n s (note 1 ) 11 t os h2 ck hosc1 ? to clko ? 7 52 0 0n s (note 1 ) 12 t ck rc l k o r i s e t i m e 1 5 3 0 n s (note 1 ) 13 t ck f clko fall time 15 30 ns (note 1 ) 14 t ck l2 io vclko ? to port out valid 0.5 t cy + 20 ns 15 t io v2 ck h port in valid before clko ? 0.25 t cy + 25 ns 16 t ck h2 io i port in hold after clko ? 0n s 17 t os h2 io vosc1 ? (q1 cycle) to port out valid 50 150 ns 18 t os h2 io iosc1 ? (q2 cycle) to port input invalid (i/o in hold time) 100 ns 19 t io v2 os h port input valid to osc1 ?? (i/o in setup time) 0n s 20 t io r port output rise time 10 25 ns 21 t io f port output fall time 10 25 ns 22 ? t inp intx pin high or low time 20 ns 23 ? t rbp rb<7:4> change intx high or low time t cy n s ? these parameters are asynchronous events not related to any internal clock edges. note 1: measurements are taken in ec mode, where clko output is 4 x t osc . note: refer to figure 31-3 for load conditions. osc1 clko i/o pin (input) i/o pin (output) q4 q1 q2 q3 10 13 14 17 20, 21 19 18 15 11 12 16 old value new value downloaded from: http:///
pic18f87k22 family ds39960d-page 506 ? 2011 microchip technology inc. figure 31-6: program memory fe tch timing diagram (8-bit) table 31-10: program memory fet ch timing requirements (8-bit) param no symbol characteristics min typ max units 150 tadv2ail address out valid to ale ? (address setup time) 0.25 t cy C 10 ns 151 tail2adl ale ? to address out invalid (address hold time) 5 ns 153 b a 01 ba0 ? to most significant data valid 0.125 t cy n s 154 b a 02 ba0 ? to least significant data valid 0.125 t cy n s 155 tail2oel ale ? to oe ? 0.125 t cy n s 161 toeh2add oe ? to a/d driven 0.125 t cy C 5 ns 162 tadv2oeh least significant data valid before oe ? (data setup time) 20 ns 162a tadv2oeh most significant data valid before oe ? (data setup time) 0.25 t cy + 20 ns 163 toeh2adi oe ? to data in invalid (data hold time) 0 ns 166 taih2aih ale ? to ale ? (cycle time) t cy n s 167 t acc address valid to data valid 0.5 t cy C 10 ns 168 toe oe ? to data valid 0.125 t cy + 5 ns 170 tubh2oeh ba0 = 0 valid before oe ? 0.25 t cy n s 170a tubl2oeh ba0 = 1 valid before oe ? 0.5 t cy n s q1 q2 q3 q4 q1 q2 osc1 ale oe address data 170 161 162 ad<7:0> address address a<19:8> address 162a ba0 data 170a 151 150 166 167 155 153 163 154 168 ce note: fmax = 25 mhz in 8-bit external memory mode. downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 507 pic18f87k22 family figure 31-7: program memo ry read timing diagram table 31-11: clko and i/o timing requirements param. no symbol characteristics min typ max units 150 tadv2all address out valid to ale ?? (address setup time) 0.25 t cy C 10 ns 151 tall2adl ale ? to address out invalid (address hold time) 5n s 155 tall2oel ale ?? to oe ? 10 0.125 t cy n s 160 tadz2oel ad high-z to oe ?? (bus release to oe )0n s 161 toeh2add oe ? to ad driven 0.125 t cy C 5 ns 162 tadv2oeh ls data valid before oe ?? (data setup time) 20 ns 163 toeh2adl oe ? to data in invalid (data hold time) 0 ns 164 talh2all ale pulse width 0.25 t cy n s 165 toel2oeh oe pulse width 0.5 t cy C 5 0.5 t cy n s 166 talh2alh ale ? to ale ? (cycle time) t cy n s 167 tacc address valid to data valid 0.75 t cy C 25 ns 168 toe oe ? to data valid 0.5 t cy C 25 ns 169 tall2oeh ale ?? to oe ? 0.625 t cy C 10 0.625 t cy + 10 ns 171 talh2csl chip enable active to ale ? 0.25 t cy C 20 ns 171a tubl2oeh ad valid to chip enable active 10 ns q1 q2 q3 q4 q1 q2 osc1 ale oe address data from external 166 160 165 161 151 162 163 ad<15:0> 167 168 155 address address 150 a<19:16> address 169 ba0 ce 171 171a operating conditions: 2.0v < v cc < 3.6v, -40c < t a < +125c unless otherwise stated. 164 downloaded from: http:///
pic18f87k22 family ds39960d-page 508 ? 2011 microchip technology inc. figure 31-8: program memory write timing diagram table 31-12: program memory write timing requirements param. no symbol characteristics min typ max units 150 tadv2all address out valid to ale ?? (address setup time) 0.25 t cy C 10 ns 151 tall2adl ale ? to address out invalid (address hold time) 5 ns 153 twrh2adl wrn ? to data out invalid (data hold time) 5 ns 154 twrl wrn pulse width 0.5 t cy C 5 0.5 t cy n s 156 tadv2wrh data valid before wrn ?? (data setup time) 0.5 t cy C 10 ns 157 tbsv2wrl byte select valid before wrn ?? (byte select setup time) 0.25 t cy n s 157a twrh2bsi wrn ? to byte select invalid (byte select hold time) 0.125 t cy C 5 ns 166 talh2alh ale ? to ale ? (cycle time) t cy n s 171 talh2csl chip enable active to ale ? 0.25 t cy C 20 ns 171a tubl2oeh ad valid to chip enable active 10 ns q1 q2 q3 q4 q1 q2 osc1 ale address data 156 150 151 153 ad<15:0> address wrh or wrl ub or lb 157 154 157a address a<19:16> address ba0 166 ce 171 171a operating conditions: 2.0v < v cc < 3.6v, -40c < t a < +125c unless otherwise stated. downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 509 pic18f87k22 family figure 31-9: reset, watchdog timer, oscillator start-up timer and power-up timer timing figure 31-10: brown-out r eset timing v dd mclr internal por pwrt time-out oscillator time-out internal reset watchdog timer reset 33 32 30 31 34 i/o pins 34 note: refer to figure 31-3 for load conditions. v dd bv dd 35 v bgap = 1.2v v irvst enable internal internal reference 36 reference voltage voltage stable downloaded from: http:///
pic18f87k22 family ds39960d-page 510 ? 2011 microchip technology inc. table 31-13: reset, watchdog timer, oscill ator start-up timer, power-up timer and brown-out reset requirements param. no. symbol characteristic min typ max units conditions 30 tmcl mclr pulse width (low) 2 ? s 31 t wdt watchdog timer time-out period (no postscaler) 4 . 0 0 m s 32 t ost oscillation start-up timer period 1024 t osc 1024 t osc t osc = osc1 period 33 t pwrt power-up timer period 65.5 140 ms 34 t ioz i/o high-impedance from mclr low or watchdog timer reset 2 ? s 35 t bor brown-out reset pulse width 200 ? sv dd ? bv dd (see d005) 36 t irvst time for internal reference voltage to become stable 2 5 ? s 37 t hlvd high/low-voltage detect pulse width 200 ? sv dd ? v hlvd 38 t csd cpu start-up time 5 10 ? s 39 t iobst time for intosc to stabilize 1 ? s downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 511 pic18f87k22 family figure 31-11: high/low-volt age detect characteristics table 31-14: high/low-voltage detect characteristics standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. sym characteristic min typ max units conditions d420 hlvd voltage on v dd transition high-to-low hlvdl<3:0> = 0000 1.80 1.86 1.90 v hlvdl<3:0> = 0001 2.03 2.12 2.13 v hlvdl<3:0> = 0010 2.24 2.33 2.35 v hlvdl<3:0> = 0011 2.40 2.49 2.53 v hlvdl<3:0> = 0100 2.50 2.59 2.62 v hlvdl<3:0> = 0101 2.70 2.75 2.84 v hlvdl<3:0> = 0110 2.82 2.93 2.97 v hlvdl<3:0> = 0111 2.95 3.07 3.10 v hlvdl<3:0> = 1000 3.24 3.30 3.41 v hlvdl<3:0> = 1001 3.42 3.48 3.59 v hlvdl<3:0> = 1010 3.61 3.67 3.79 v hlvdl<3:0> = 1011 3.82 3.87 4.01 v hlvdl<3:0> = 1100 4.06 4.21 4.26 v hlvdl<3:0> = 1101 4.33 4.42 4.55 v hlvdl<3:0> = 1110 4.64 4.77 4.87 v v hlvd hlvdif v dd (hlvdif set by hardware) (hlvdif can be cleared in software) v hlvd for vdirmag = 1 : for vdirmag = 0 : v dd downloaded from: http:///
pic18f87k22 family ds39960d-page 512 ? 2011 microchip technology inc. figure 31-12: timer0 and timer1 exte rnal clock timings table 31-15: timer0 and timer1 external clock requirements param no. symbol characteristic min max units conditions 40 t t 0h t0cki high pulse width no prescaler 0.5 t cy + 20 ns with prescaler 10 ns 41 t t 0l t0cki low pulse width no prescaler 0.5 t cy + 20 ns with prescaler 10 ns 42 t t 0p t0cki period no prescaler t cy + 10 ns with prescaler greater of: 20 ns or (t cy + 40)/n n sn = p r e s c a l e value (1, 2, 4,..., 256) 45 t t 1h t1cki high time synchronous, no prescaler 0.5 t cy + 20 ns synchronous, with prescaler 10 ns asynchronous 30 ns 46 t t 1l t1cki low time synchronous, no prescaler 0.5 t cy + 5 ns synchronous, with prescaler 10 ns asynchronous 30 ns 47 t t 1p t1cki input period synchronous greater of: 20 ns or (t cy + 40)/n n sn = p r e s c a l e value (1, 2, 4, 8) asynchronous 60 ns f t 1 t1cki oscillator input frequency range dc 50 khz 48 t cke 2 tmr i delay from external t1cki clock edge to timer increment 2 t osc 7 t osc note: refer to figure 31-3 for load conditions. 46 47 45 48 41 42 40 t0cki t1cki tmr0 or tmr1 downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 513 pic18f87k22 family figure 31-13: capture/compare/pwm timi ngs (eccp1, eccp2 modules) table 31-16: capture/compare/pwm requirements (eccp1, eccp2 modules) param no. symbol characteristic min max units conditions 50 t cc l ccpx input low time no prescaler 0.5 t cy + 20 ns with prescaler 10 ns 51 t cc h ccpx input high time no prescaler 0.5 t cy + 20 ns with prescaler 10 ns 52 t cc p ccpx input period 3 t cy + 40 n ns n = prescale value (1, 4 or 16) 53 t cc r ccpx output fall time 25 ns 54 t cc f ccpx output fall time 25 ns note: refer to figure 31-3 for load conditions. ccpx (capture mode) 50 51 52 ccpx 53 54 (compare or pwm mode) downloaded from: http:///
pic18f87k22 family ds39960d-page 514 ? 2011 microchip technology inc. figure 31-14: example spi ma ster mode timing (cke = 0 ) table 31-17: example spi mode requirements (master mode, cke = 0 ) param no. symbol characteristic min max units conditions 73 t di v2 sc h, t di v2 sc l setup time of sdix data input to sckx edge 20 ns 73a t b 2 b last clock edge of byte 1 to the 1st clock edge of byte 2 1.5 t cy + 40 ns 74 t sc h2 di l, t sc l2 di l hold time of sdix data input to sckx edge 40 ns 75 t do r sdox data output rise time 25 ns 76 t do f sdox data output fall time 25 ns 78 t sc r sckx output rise time (master mode) 25 ns 79 t sc f sckx output fall time (master mode) 25 ns 80 t sc h2 do v, t sc l2 do v sdox data output valid after sckx edge 50 ns sckx (ckpx = 0 ) sckx (ckpx = 1 ) sdox sdix 73 74 75, 76 78 79 80 79 78 msb lsb bit 6 - - - - - - 1 lsb in bit 6 - - - - 1 note: refer to figure 31-3 for load conditions. msb in downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 515 pic18f87k22 family figure 31-15: example spi ma ster mode timing (cke = 1 ) table 31-18: example spi mode requirements (master mode, cke = 1 ) param. no. symbol characteristic min max units conditions 73 t di v2 sc h, t di v2 sc l setup time of sdix data input to sckx edge 20 ns 73a t b 2 b last clock edge of byte 1 to the 1st clock edge of byte 2 1.5 t cy + 40 ns 74 t sc h2 di l, t sc l2 di l hold time of sdix data input to sckx edge 40 ns 75 t do r sdox data output rise time 25 ns 76 t do f sdox data output fall time 25 ns 78 t sc r sckx output rise time (master mode) 25 ns 79 t sc f sckx output fall time (master mode) 25 ns 80 t sc h2 do v, t sc l2 do v sdox data output valid after sckx edge 50 ns 81 t do v2 sc h, t do v2 sc l sdox data output setup to sckx edge t cy n s sckx (ckpx = 0 ) sckx (ckpx = 1 ) sdox sdix 81 74 75, 76 78 80 msb 79 73 bit 6 - - - - - - 1 lsb in bit 6 - - - - 1 lsb note: refer to figure 31-3 for load conditions. msb in downloaded from: http:///
pic18f87k22 family ds39960d-page 516 ? 2011 microchip technology inc. figure 31-16: example spi slave mode timing (cke = 0 ) table 31-19: example spi mode requirements (slave mode timing, cke = 0 ) param no. symbol characteristic min max units conditions 70 t ss l2 sc h, t ss l2 sc l ssx ? to sckx ? or sckx ? input 3 t cy n s 70a t ss l2wb ssx to write to sspbuf 3 t cy n s 71 t sc h sckx input high time (slave mode) continuous 1.25 t cy + 30 ns 71a single byte 40 ns (note 1 ) 72 t sc l sckx input low time (slave mode) continuous 1.25 t cy + 30 ns 72a single byte 40 ns (note 1 ) 73 t di v2 sc h, t di v2 sc l setup time of sdix data input to sckx edge 20 ns 73a t b 2 b last clock edge of byte 1 to the first clock edge of byte 2 1.5 t cy + 40 ns (note 2 ) 74 t sc h2 di l, t sc l2 di l hold time of sdix data input to sckx edge 40 ns 75 t do r sdox data output rise time 25 ns 76 t do f sdox data output fall time 25 ns 77 t ss h2 do z ssx ? to sdox output high-impedance 10 50 ns 78 t sc r sckx output rise time (master mode) 25 ns 79 t sc f sckx output fall time (master mode) 25 ns 80 t sc h2 do v, t sc l2 do v sdox data output valid after sckx edge 50 ns 83 t sc h2 ss h, t sc l2 ss h ssx ? after sckx edge 1.5 t cy + 40 ns note 1: requires the use of parameter #73a. 2: only if parameter #71a and #72a are used. ssx sckx (ckpx = 0 ) sckx (ckp = 1 ) sdox sdix 70 71 72 73 74 75, 76 77 78 79 80 79 78 msb lsb bit 6 - - - - - - 1 bit 6 - - - - 1 lsb in 83 note: refer to figure 31-3 for load conditions. msb in downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 517 pic18f87k22 family figure 31-17: example spi slave mode timing (cke = 1 ) table 31-20: example spi slave mode requirements (cke = 1 ) param no. symbol characteristic min max units conditions 70 t ss l2 sc h, t ss l2 sc l ssx ? to sckx ? or sckx ? input 3 t cy n s 70a t ss l2wb ssx to write to sspbuf 3 t cy n s 71 t sc h sckx input high time (slave mode) continuous 1.25 t cy + 30 ns 71a single byte 40 ns (note 1 ) 72 t sc l sckx input low time (slave mode) continuous 1.25 t cy + 30 ns 72a single byte 40 ns (note 1 ) 73a t b 2 b last clock edge of byte 1 to the first clock edge of byte 2 1.5 t cy + 40 ns (note 2 ) 74 t sc h2 di l, t sc l2 di l hold time of sdix data input to sckx edge 40 ns 75 t do r sdox data output rise time 25 ns 76 t do f sdox data output fall time 25 ns 77 t ss h2 do z ssx ? to sdox output high-impedance 10 50 ns 78 t sc r sckx output rise time (master mode) 25 ns 79 t sc f sckx output fall time (master mode) 25 ns 80 t sc h2 do v, t sc l2 do v sdox data output valid after sckx edge 50 ns 82 t ss l2 do v sdox data output valid after ssx ? edge 50 ns 83 t sc h2 ss h, t sc l2 ss h ssx ? after sckx edge 1.5 t cy + 40 ns note 1: requires the use of parameter #73a. 2: only if parameter #71a and #72a are used. ssx sckx (ckpx = 0 ) sckx (ckpx = 1 ) sdox sdix 70 71 72 82 74 75, 76 msb bit 6 - - - - - - 1 lsb 77 bit 6 - - - - 1 lsb in 80 83 note: refer to figure 31-3 for load conditions. msb in downloaded from: http:///
pic18f87k22 family ds39960d-page 518 ? 2011 microchip technology inc. figure 31-18: i 2 c? bus start/stop bits timing table 31-21: i 2 c? bus start/stop bits requirements (slave mode) param. no. symbol characteristic min max units conditions 90 t su : sta start condition 100 khz mode 4700 ns only relevant for repeated start condition setup time 400 khz mode 600 91 t hd : sta start condition 100 khz mode 4000 ns after this period, the first clock pulse is generated hold time 400 khz mode 600 92 t su : sto stop condition 100 khz mode 4700 ns setup time 400 khz mode 600 93 t hd : sto stop condition 100 khz mode 4000 ns hold time 400 khz mode 600 note: refer to figure 31-3 for load conditions. 91 92 93 sclx sdax start condition stop condition 90 downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 519 pic18f87k22 family figure 31-19: i 2 c? bus data timing table 31-22: i 2 c? bus data requirements (slave mode) param. no. symbol characteristic min max units conditions 100 t high clock high time 100 khz mode 4.0 ? s 400 khz mode 0.6 ? s mssp module 1.5 t cy 101 t low clock low time 100 khz mode 4.7 ? s 400 khz mode 1.3 ? s mssp module 1.5 t cy 102 t r sdax and sclx rise time 100 khz mode 1000 ns 400 khz mode 20 + 0.1 c b 300 ns c b is specified to be from 10 to 400 pf 103 t f sdax and sclx fall time 100 khz mode 300 ns 400 khz mode 20 + 0.1 c b 300 ns c b is specified to be from 10 to 400 pf 90 t su : sta start condition setup time 100 khz mode 4.7 ? s only relevant for repeated start condition 400 khz mode 0.6 ? s 91 t hd : sta start condition hold time 100 khz mode 4.0 ? s after this period, the first clock pulse is generated 400 khz mode 0.6 ? s 106 t hd : dat data input hold time 100 khz mode 0 ns 400 khz mode 0 0.9 ? s 107 t su : dat data input setup time 100 khz mode 250 ns (note 2 ) 400 khz mode 100 ns 92 t su : sto stop condition setup time 100 khz mode 4.7 ? s 400 khz mode 0.6 ? s 109 t aa output valid from clock 100 khz mode 3500 ns (note 1 ) 400 khz mode ns 110 t buf bus free time 100 khz mode 4.7 ? s time the bus must be free before a new transmission can start 400 khz mode 1.3 ? s d102 c b bus capacitive loading 400 pf note 1: as a transmitter, the device must provide this internal mi nimum delay time to bridge the undefined region (min. 300 ns) of the falling edge of sclx to avoid unintended generation of start or stop conditions. 2: a fast mode i 2 c? bus device can be used in a standard mode i 2 c bus system, but the requirement, t su : dat ? 250 ns, must then be met. this will automatically be the case if the device does not stretch the low period of the sclx signal. if such a device does stretch the low period of the sclx si gnal, it must output the next data bit to the sdax line, t r max. + t su : dat = 1000 + 250 = 1250 ns (according to the standard mode i 2 c bus specification), before the sclx line is released. note: refer to figure 31-3 for load conditions. 90 91 92 100 101 103 106 107 109 109 110 102 sclx sdax in sdax out downloaded from: http:///
pic18f87k22 family ds39960d-page 520 ? 2011 microchip technology inc. figure 31-20: mssp i 2 c? bus start/stop bits timing waveforms table 31-23: mssp i 2 c? bus start/stop bits requirements figure 31-21: mssp i 2 c? bus data timing param. no. symbol characteristic min max units conditions 90 t su : sta start condition 100 khz mode 2(t osc )(brg + 1) ns only relevant for repeated start condition setup time 400 khz mode 2(t osc )(brg + 1) 1 mhz mode ( 1 ) 2(t osc )(brg + 1) 91 t hd : sta start condition 100 khz mode 2(t osc )(brg + 1) ns after this period, the first clock pulse is generated hold time 400 khz mode 2(t osc )(brg + 1) 1 mhz mode ( 1 ) 2(t osc )(brg + 1) 92 t su : sto stop condition 100 khz mode 2(t osc )(brg + 1) ns setup time 400 khz mode 2(t osc )(brg + 1) 1 mhz mode ( 1 ) 2(t osc )(brg + 1) 93 t hd : sto stop condition 100 khz mode 2(t osc )(brg + 1) ns hold time 400 khz mode 2(t osc )(brg + 1) 1 mhz mode ( 1 ) 2(t osc )(brg + 1) note 1: maximum pin capacitance = 10 pf for all i 2 c? pins. note: refer to figure 31-3 for load conditions. 91 93 sclx sdax start condition stop condition 90 92 note: refer to figure 31-3 for load conditions. 90 91 92 100 101 103 106 107 109 109 110 102 sclx sdax in sdax out downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 521 pic18f87k22 family table 31-24: mssp i 2 c? bus data requirements param. no. symbol characteristic min max units conditions 100 t high clock high time 100 khz mode 2(t osc )(brg + 1) 400 khz mode 2(t osc )(brg + 1) 1 mhz mode ( 1 ) 2(t osc )(brg + 1) 101 t low clock low time 100 khz mode 2(t osc )(brg + 1) 400 khz mode 2(t osc )(brg + 1) 1 mhz mode ( 1 ) 2(t osc )(brg + 1) 102 t r sdax and sclx rise time 100 khz mode 1000 ns c b is specified to be from 10 to 400 pf 400 khz mode 20 + 0.1 c b 300 ns 1 mhz mode ( 1 ) 300 ns 103 t f sdax and sclx fall time 100 khz mode 300 ns c b is specified to be from 10 to 400 pf 400 khz mode 20 + 0.1 c b 300 ns 1 mhz mode ( 1 ) 100 ns 90 t su : sta start condition setup time 100 khz mode 2(t osc )(brg + 1) only relevant for repeated start condition 400 khz mode 2(t osc )(brg + 1) 1 mhz mode ( 1 ) 2(t osc )(brg + 1) 91 t hd : sta start condition hold time 100 khz mode 2(t osc )(brg + 1) after this period, the first clock pulse is generated 400 khz mode 2(t osc )(brg + 1) 1 mhz mode ( 1 ) 2(t osc )(brg + 1) 106 t hd : dat data input hold time 100 khz mode 0 ns 400 khz mode 0 0.9 ? s 1 mhz mode ( 1 ) n s 107 t su : dat data input setup time 100 khz mode 250 ns (note 2 ) 400 khz mode 100 ns 1 mhz mode ( 1 ) n s 92 t su : sto stop condition setup time 100 khz mode 2(t osc )(brg + 1) 400 khz mode 2(t osc )(brg + 1) 1 mhz mode ( 1 ) 2(t osc )(brg + 1) 109 t aa output valid from clock 100 khz mode 3500 ns 400 khz mode 1000 ns 1 mhz mode ( 1 ) n s 110 t buf bus free time 100 khz mode 4.7 ? s time the bus must be free before a new transmission can start 400 khz mode 1.3 ? s 1 mhz mode ( 1 ) ? s d102 c b bus capacitive loading 400 pf note 1: maximum pin capacitance = 10 pf for all i 2 c? pins. 2: a fast mode i 2 c bus device can be used in a standard mode i 2 c bus system, but parameter #107 ? 250 ns must then be met. this will automatically be the case if the device does not stretch the low period of the sclx signal. if such a device does stretch the low period of the sclx signal, it must output the next data bit to the sdax line, parameter #102 + parameter #107 = 1000 + 250 = 1250 ns (for 100 khz mode), before the sclx line is released. downloaded from: http:///
pic18f87k22 family ds39960d-page 522 ? 2011 microchip technology inc. figure 31-22: eusart synchrono us transmission (master/slave) timing table 31-25: eusart/ausart synchronous transmission requirements figure 31-23: eusart/ausart sy nchronous receive (master/slave) timing table 31-26: eusart/ausart synchronous receive requirements param no. symbol characteristic min max units conditions 120 t ck h2 dt v sync xmit (master and slave) clock high to data out valid 40 ns 121 t ckrf clock out rise time and fall time (master mode) 20 ns 122 t dtrf data out rise time and fall time 20 ns param. no. symbol characteristic min max units conditions 125 t dt v2 ckl sync rcv (master and slave) data hold before ckx ? (dtx hold time) 10 ns 126 t ck l2 dtl data hold after ckx ? (dtx hold time) 15 ns 121 121 120 122 txx/ckx rxx/dtx pin pin note: refer to figure 31-3 for load conditions. 125 126 txx/ckx rxx/dtx pin pin note: refer to figure 31-3 for load conditions. downloaded from: http:///
? 2011 microchip technology inc. ds39960d-page 523 pic18f87k22 family table 31-27: a/d converter characteristics: pic18f87k22 family (industrial) param no. sym characteristic min typ max units conditions a01 n r resolution 12 bit ? v ref ? 5.0v a03 e il integral linearity error 1 6.0 lsb ? v ref = 5.0v a04 e dl differential linearity error 1 +3.0/-1.0 lsb ? v ref = 5.0v a06 e off offset error 1 9.0 lsb ? v ref = 5.0v a07 e gn gain error 1 8.0 lsb ? v ref = 5.0v a10 monotonicity ( 1 ) ?? v ss ? v ain ? v ref a20 ? v ref reference voltage range (v refh C v refl ) 3v dd C v ss v a21 v refh reference voltage high v ss + 3.0v v dd + 0.3v v a22 v refl reference voltage low v ss C 0.3v v dd C 3.0v v a25 v ain analog input voltage v refl v refh v a30 z ain recommended impedance of analog voltage source 2 . 5k ? a50 i ref v ref input current ( 2 ) 5 150 ? a ? a during v ain acquisition during a/d conversion cycle note 1: the a/d conversion result doesnt decrease with an increase in the input voltage. 2: v refh current is from the ra3/an3/v ref + pin or v dd , whichever is selected as the v refh source. v refl current is from the ra2/an2/v ref - pin or v ss , whichever is selected as the v refl source. downloaded from: http:///
pic18f87k22 family ds39960d-page 524 ? 2011 microchip technology inc. figure 31-24: a/d conversion timing table 31-28: a/d conversion requirements param no. symbol characteristic min max units conditions 130 t ad a/d clock period 0.8 12.5 ( 1 ) s t osc -based, v ref ? 3.0v 1.4 25 ( 1 ) s v dd = 3.0v; t osc -based, v ref full range 1 s a/d rc mode 3 s v dd = 3.0v; a/d rc mode 131 t cnv conversion time (not including acquisition time) ( 2 ) 14 15 t ad 132 t acq acquisition time ( 3 ) 1.4 s -40c to +125c 135 t swc switching time from convert ? sample (note 4 ) 137 t dis discharge time 0.2 s -40c to +125c note 1: the time of the a/d clock period is dependent on the device frequency and the t ad clock divider. 2: adres registers may be read on the following t cy cycle. 3: the time for the holding capacitor to acquire the new input voltage wh en the voltage changes full scale after the conversion (v dd to v ss or v ss to v dd ). the source impedance ( r s ) on the input channels is 50 ? . 4: on the following cycle of the device clock. 131 130 132 bsf adcon0, go q4 a/d clk a/d data adres adif go sample old_data sampling stopped done new_data (note 2) 11 10 9 2 1 0 note 1: if the a/d clock source is selected as rc, a time of t cy is added before the a/d clock starts. this allows the sleep instruction to be executed. 2: this is a minimal rc delay (typically 100 ns), which also disconnects the holding capacitor from the analog input. . . . . . . t cy (note 1) downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 525 pic18f87k22 family 32.0 packaging information 32.1 package marking information 3 e 3 e 64-lead tqfp xxxxxxxxxx xxxxxxxxxx xxxxxxxxxx yywwnnn example 18f67k22 -i/pt 1110017 80-lead tqfp xxxxxxxxxxxx xxxxxxxxxxxx yywwnnn example pic18f87k22 -i/pt 1110017 legend: xx...x customer-specific information y year code (last digit of calendar year) yy year code (last 2 digits of calendar year) ww week code (week of january 1 is week 01) nnn alphanumeric traceability code pb-free jedec designator for matte tin (sn) * this package is pb-free. the pb-free jedec designator ( ) can be found on the outer packaging for this package. note : in the event the full microchip part number cannot be marked on one line, it will be carried over to the next line, thus limiting the number of available characters for customer-specific information. 3 e 3 e 3 e 64-lead qfn xxxxxxxxxx xxxxxxxxxx xxxxxxxxxx yywwnnn example 18f67k22 -i/mr 1110017 downloaded from: http:///
pic18f87k22 family ds39960d-page 526 ? 2009-2011 microchip technology inc. 32.2 package details the following sections give the technical details of the packages.

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? 2009-2011 microchip technology inc. ds39960d-page 527 pic18f87k22 family note: for the most current package drawings, please see the microchip packaging specification located at http://www.microchip.com/packaging downloaded from: http:///
pic18f87k22 family ds39960d-page 528 ? 2009-2011 microchip technology inc. note: for the most current package drawings, please see the microchip packaging specification located at http://www.microchip.com/packaging downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 529 pic18f87k22 family note: for the most current package drawings, please see the microchip packaging specification located at http://www.microchip.com/packaging downloaded from: http:///
pic18f87k22 family ds39960d-page 530 ? 2009-2011 microchip technology inc. note: for the most current package drawings, please see the microchip packaging specification located at http://www.microchip.com/packaging downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 531 pic18f87k22 family )

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pic18f87k22 family ds39960d-page 532 ? 2009-2011 microchip technology inc. note: for the most current package drawings, please see the microchip packaging specification located at http://www.microchip.com/packaging downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 533 pic18f87k22 family appendix a: revision history revision a (november 2009) original data sheet for pic18f87k22 family devices. revision b (may 2010) minor edits to text throughout document. replaced all tbds with the correct value. revision c (march 2011) section 2.4 voltage regulator pins (envreg and v cap /v ddcore ) has been replaced with a new and more detailed description and the 80-pin tqfp diagrams have been updated. minor text edits throughout document. revision d (june 2011) updated section 31.2 dc characteristics: power-down and supply current pic18f87k22 family (industrial/extended) and table 31-8 with new electrical specification information. the extended temperature information has been included in this revision. downloaded from: http:///
pic18f87k22 family ds39960d-page 534 ? 2009-2011 microchip technology inc. appendix b: migration from pic18f87j11 and pic18f8722 to pic18f87k22 devices in the pic18f87k22, pic18f87j11 and pic18f8722 families are similar in their functions and features. code can be migrated from the other families to the pic18f87k22 without many changes. the differ- ences between the device families are listed in table b-1 . table b-1: notable differences between pic18f87k22, pic18f87j11 and pic18f8722 families characteristic pic18f87k22 family 18f87j11 family pic18f8722 family max operating frequency 64 mhz 48 mhz 40 mhz max program memory 128 kbytes 128 kbytes 128 kbytes data memory 3,862 bytes 3,930 bytes 3,930 bytes program memory endurance 10,000 write/erase (minimum) 10,000 write/erase (minimum) 10,000 write/erase (minimum) single word write for flash no yes no oscillator options pll can be used with intosc pll can be used with intosc pll can be used with intosc ctmu yes no no rtcc yes no no sosc oscillator options ticki clock low-power oscillator option for sosc t1cki can be used as a clock without enabling the sosc oscillator no no intosc up to 16 mhz up to 8 mhz up to 8 mhz spi/i 2 c? 2 2 2 timers 11 5 5 eccp 3 3 ccp 7 2 2 data eeprom yes no yes programmable bor multiple level bor one level bor multiple level bor wdt prescale options 22 16 16 5v operation yes no (3.3v) yes nanowatt xlp yes no no regulator yes yes no low-power bor yes no no a/d converter 12-bit resolution, 24 input channels, differential 10-bit resolution, 15 input channels, non-differential 10-bit resolution, 16 input channels, non-differential internal temperature sensor yes no no programmable hlvd yes no yes eusart 2 eusarts 2 eusarts 2 eusarts comparators 3 2 2 oscillator options 14 options by f osc <3:0> 8 options by f osc <3:0> 12 options by f osc <3:0> ultra-low-power wake-up (ulpw) yes no no power-up timer yes yes yes mclr pin as input port yes no yes downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 535 pic18f87k22 family index a a/d .................................................................................... 351 acquisition requirements ........................................ . 362 analog port pins, configuring................................... 363 associated registers ................................................ 366 automatic acquisition time, selecting and configuring ....................................................... 363 configuring the module........................................... .. 361 control registers ...................................................... 352 conversion clock (t ad ) ............................................ 363 conversion requirements ........................................ 524 conversion sequence............................................... 361 conversion status (go/done bit) ........................... 359 conversions .............................................................. 364 converter characteristics ......................................... 523 converter interrupt, configuring ............................... 361 differential converter ................................................ 3 51 operation in power-managed modes ....................... 365 use of special event triggers .................................. 365 absolute maximum ratings .............................................. 485 ac (timing) characteristics .............................................. 50 1 load conditions for device timing specifications.... 502 parameter symbology .............................................. 501 temperature and voltage specifications .................. 502 timing conditions ............................................ ......... 502 ackstat ......................................................................... 31 7 ackstat status flag ...................................................... 317 adcon0 register go/done bit............................................................ 359 addfsr ........................................................................... 474 addlw ............................................................................. 437 addulnk......................................................................... 474 addwf ............................................................................. 437 addwfc .......................................................................... 4 38 analog-to-digital converter. see a/d. andlw ............................................................................. 438 andwf ............................................................................. 439 assembler mpasm assembler................................................... 482 auto-wake-up on sync break character .......................... 342 b baud rate generator .............................................. .......... 313 bc ..................................................................................... 439 bcf ................................................................................... 440 bf ..................................................................................... 317 bf status flag .................................................................. 317 block diagrams 16-bit byte select mode ........................................... 127 16-bit byte write mode ............................................. 125 16-bit word write mode............................................ 126 8-bit multiplexed mode example .............................. 129 a/d ............................................................................ 360 a/d result justification ............................................. 355 analog input model ............................................. ...... 361 baud rate generator.............................................. .. 313 capture mode operation .................................. 251, 263 comparator analog input model ............................... 370 comparator configurations....................................... 372 comparator simplified .............................................. 367 comparator voltage reference ................................ 376 comparator voltage reference output buffer example ................................................. 377 compare mode operation ................................ 253, 264 connections for on-chip voltage regulator ............ 421 crystal/ceramic resonator operation (hs or hspll).................................................... 50 ctmu ....................................................................... 385 ctmu current source calibration circuit ................ 391 ctmu typical connections and internal configuration for pulse delay generation ........ 399 ctmu typical connections and internal configuration for time measurement ............... 398 device clock............................................................... 44 differential channel measurement ........................... 351 enhanced pwm mode........................................... ... 265 eusart receive ..................................................... 340 eusart transmit .................................................... 338 external clock input operation (ec) .......................... 51 external clock input operation (hs) .......................... 51 external components for sosc low-power oscillator.......................... ........................... ...... 201 external power-on reset circuit (slow v dd power-up) ......................................... 75 fail-safe clock monitor (fscm)............................... 424 full-bridge application example............................... 269 generic i/o port operation....................................... 165 half-bridge applications .......................................... . 275 high/low-voltage detect with external input ........... 380 interrupt logic............................................ ............... 142 intio1 oscillator mode .............................................. 52 intio2 oscillator mode .............................................. 52 mssp (spi mode) .......................................... .......... 281 msspx (i 2 c master mode) ....................................... 311 msspx (i 2 c mode) ................................................. .. 291 on-chip reset circuit................................................. 73 pic18f6xk22............................................................. 13 pic18f8xk22............................................................. 14 pll ............................................................................. 51 portd and porte (parallel slave port)................ 189 pwm operation (simplified) ..................................... 255 rc oscillator mode .................................................... 49 rcio oscillator mode................ ................................. 49 reads from flash program memory ........................ 115 rtcc........................................................................ 227 rtcc clock source multiplexing ............................. 238 simplified steering.................................................... 278 single channel measurement .................................. 351 single comparator.................................................... 370 spi master/slave connection................................... 285 table read operation ............................................ .. 111 table write operation .............................................. 112 table writes to flash program memory ................... 117 timer0 in 16-bit mode .............................................. 194 timer0 in 8-bit mode ................................................ 194 timer1 ...................................................................... 200 timer2 ...................................................................... 210 timer3/5/7 ................................................................ 215 timer4 ...................................................................... 224 ultra low-power wake-up initialization...................... 70 using open-drain output (usart) ......................... 167 watchdog timer ............................................ ........... 419 bn..................................................................................... 440 bnc .................................................................................. 441 bnn .................................................................................. 441 bnov ............................................................................... 442 downloaded from: http:///
pic18f87k22 family ds39960d-page 536 ? 2009-2011 microchip technology inc. bnz ................................................................................... 442 bor. see brown-out reset. bov................................................................................... 445 bra................................................................................... 443 break character (12-bit) transmit and receive ............... 344 brg. see baud rate generator. brown-out reset (bor) ...................................................... 75 detecting..................................................................... 75 bsf ................................................................................... 443 btfsc .............................................................................. 444 btfss............................................................................... 444 btg................................................................................... 445 bz...................................................................................... 446 c c compilers mplab c18 .............................................................. 482 call ................................................................................. 446 callw.............................................................................. 475 capture (ccp module)........................................... ........... 250 ccpr4h:ccpr4l registers.................................... 250 pin configuration ...................................................... 250 prescaler................................................................... 2 51 software interrupt ..................................................... 251 timer1/3/5/7 mode selection .................................. .. 250 capture (eccp module) ............................................ ....... 263 ccprxh:ccprxl registers .................................... 263 pin configuration ...................................................... 263 prescaler................................................................... 2 63 software interrupt ..................................................... 263 timer1/2/3/4/6/8/10/12 mode selection .................... 263 capture, compare, timer1/3/5/7 associated registers ................................................ 253 capture/compare/pwm (ccp)......................................... 245 capture mode. see capture. ccp mode and timer resources ............................. 249 ccp6/7/8/9 pin assignment ..................................... 250 ccprxh register ..................................................... 249 ccprxl register...................................................... 249 compare mode. see compare. configuration............................................................. 249 open-drain output option ........................................ 250 charge time measurement unit (ctmu) ......................... 385 associated registers ................................................ 401 calibrating the module .............................................. 390 creating a delay ....................................................... 399 effects of a reset...................................................... 401 measuring capacitance with the ctmu ................... 396 measuring temperature............................................ 400 measuring time ........................................................ 398 module initialization ........................................ .......... 390 operation .................................................................. 389 during sleep and idle modes............................ 401 clock sources ..................................................................... 48 default system clock on reset .................................. 49 selection ..................................................................... 4 8 clrf................................................................................. 447 clrwdt........................................................................... 447 code examples 16 x 16 signed multiply routine ............................... 140 16 x 16 unsigned multiply routine ........................... 140 8 x 8 signed multiply routine ................................... 139 8 x 8 unsigned multiply routine ............................... 139 capacitance calibration routine .............................. 395 changing between capture prescalers ............ 251, 263 computed goto using an offset value.................... 91 current calibration routine ...................................... 393 data eeprom read................................................ 136 data eeprom refresh routine............................... 137 data eeprom write ................................................ 136 erasing a flash program memory row.................... 116 fast register stack .................................................... 91 how to clear ram (bank 1) using indirect addressing........................................... 105 initializing porta..................................................... 170 initializing portb..................................................... 172 initializing portc .................................................... 174 initializing portd .................................................... 176 initializing porte..................................................... 178 initializing portf..................................................... 181 initializing portg .................................................... 183 initializing porth .................................................... 185 initializing portj ..................................................... 187 loading the ssp1buf (ssp1sr) register.............. 284 reading a flash program memory word ................. 115 routine for capacitive touch switch........................ 397 routine for temperature measurement using internal diode ......................................... 400 saving status, wreg and bsr registers in ram.............................................................. 163 setting the rtcwren bit ........................................ 239 setup for ctmu calibration routines ...................... 392 ultra low-power wake-up initialization ...................... 70 writing to flash program memory .................... 119C120 code protection ............................................. ................... 403 comf ............................................................................... 448 comparator....................................................................... 367 analog input connection, considerations ................ 370 associated registers ................................................ 374 configuration and control......................................... 371 effects of a reset ..................................................... 374 enable and input selection....................................... 371 enable and output selection .................................... 371 interrupts .................................................................. 373 operation .................................................................. 370 operation during sleep ............................................ 374 response time.............................................. ........... 370 comparator specifications................................................ 500 comparator voltage reference ....................................... . 375 accuracy and error ................................................... 376 associated registers ................................................ 377 configuring ............................................................... 375 connection considerations....................................... 376 effects of a reset ..................................................... 376 operation during sleep ............................................ 376 compare (ccp module) ............................................. ...... 252 ccp pin configuration.............................................. 252 ccpr4 register ....................................................... 252 software interrupt ..................................................... 252 special event trigger ............................................... 252 timer1/3/5/7 mode selection.................................... 252 compare (eccp module)............................................. .... 264 ccprx register ....................................................... 264 pin configuration ...................................................... 2 64 software interrupt ..................................................... 264 special event trigger ....................................... 221, 264 timer1/2/3/4/6/8/10/12 mode selection.................... 264 computed goto................................................................ 91 configuration bits ............................................................. 403 configuration mismatch (cm) reset................................... 76 configuration register protection..................................... 42 9 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 537 pic18f87k22 family core features easy migration ............................................................ 10 extended instruction set....................................... ........ 9 external memory bus (emb) ........................................ 9 memory options............................................................ 9 nanowatt technology ............................................. ...... 9 oscillator options and features ................................... 9 cpfseq ........................................................................... 448 cpfsgt ........................................................................... 449 cpfslt ............................................................................ 449 crystal oscillator/ceramic resonator ................................. 50 customer change notification service ............................. 547 customer notification service........................................... 547 customer support.............................................. ............... 547 d data addressing modes............................................ ........ 105 comparing addressing modes with the extended instruction set enabled .................... 109 direct......................................................................... 105 indexed literal offset........................................... ..... 108 bsr .................................................................. 110 instructions affected ......................................... 108 mapping access bank ...................................... 110 indirect ...................................................................... 105 inherent and literal ............................................ ....... 105 data eeprom code protection ............................................. ........... 429 data eeprom memory associated registers ................................................ 138 eeadr and eeadrh registers .............................. 133 eecon1 and eecon2 registers ............................ 133 operation during code-protect ................................ 137 overview ................................................................... 133 reading.................................................. ................... 135 spurious write protection ......................................... 137 using......................................................................... 137 write verify ............................................................... 135 writing....................................................................... 135 data memory ...................................................................... 94 access bank ............................................................... 96 bank select register (bsr)........................................ 94 extended instruction set....................................... .... 108 general purpose registers......................................... 96 memory maps pic18fx5k22/x7kj22 devices ......................... 95 special function registers ................................. 97 special function registers (sfrs)............................. 97 daw.................................................................................. 450 dc characteristics ctmu current source .............................................. 498 pic18f87k22 family (industrial).............................. 497 power-down and supply current ............................. 488 supply voltage.............................................. ............ 487 dcfsnz ........................................................................... 451 decf ................................................................................ 450 decfsz............................................................................ 451 default system clock.......................................................... 49 details on individual family members ................................ 11 development support .............................................. ......... 481 device overview ................................................................... 9 features (64-pin devices) .......................................... 12 features (80-pin devices) .......................................... 12 direct addressing.............................................................. 106 e effect on standard pic18 instructions.............................. 478 effects of power-managed modes on various clock sources ............................................................ 55 electrical characteristics .................................................. 48 5 enhanced capture/compare/pwm (eccp)..................... 259 capture mode. see capture. compare mode. see compare. enhanced pwm mode........................................... ... 265 auto-restart ..................................................... 274 auto-shutdown ................................................. 272 direction change in full-bridge output mode............................................. 271 full-bridge application...................................... 269 full-bridge mode ............................................. . 269 half-bridge application ..................................... 268 half-bridge application examples .................... 275 half-bridge mode.............................................. 268 output relationships (active-high and active-low)............................................... 266 output relationships diagram.......................... 267 programmable dead-band delay..................... 275 shoot-through current..................................... 275 start-up considerations.................................... 272 outputs and configuration........................................ 262 timer resources ...................................................... 262 enhanced capture/compare/pwm (eccp) and timer1/2/3/4/6/8/10/12 associated registers................................................ 279 enhanced universal synchronous asynchronous receiver transmitter (eusart). see eusart. equations 16 x 16 signed multiplication algorithm.................... 140 16 x 16 unsigned multiplication algorithm................ 140 a/d acquisition time ................................................ 362 a/d minimum charging time ................................... 362 calculating the minimum required acquisition time ............................................... 362 errata .............................................................................. ...... 8 eusart asynchronous mode.............................................. ... 337 12-bit break transmit and receive.................. 344 associated registers, receive......................... 341 associated registers, transmit........................ 339 auto-wake-up on sync break .......................... 342 receiver ........................................................... 340 reception sequence ........................................ 340 reception with address detect enabled sequence ................................................ . 340 setting up 9-bit mode with address detect ...... 340 transmission sequence ................................... 337 transmitter ....................................................... 337 baud rate generator operation in power-managed mode................. 331 baud rate generator (brg) .................................... 331 associated registers........................................ 332 auto-baud rate detect..................................... 335 baud rate error, calculating............................ 332 baud rates, asynchronous modes .................. 333 high baud rate select (brgh bit) .................. 331 sampling .......................................................... 331 downloaded from: http:///
pic18f87k22 family ds39960d-page 538 ? 2009-2011 microchip technology inc. synchronous master mode ....................................... 345 associated registers, receive ......................... 348 associated registers, transmit ........................ 346 reception.......................................................... 347 reception sequence......................................... 347 transmission..................................................... 345 transmission sequence ................................... 345 synchronous slave mode ......................................... 349 associated registers, receive ......................... 350 associated registers, transmit ........................ 349 reception.......................................................... 350 reception sequence......................................... 350 transmission..................................................... 349 transmission sequence ................................... 349 extended instruction set addfsr ................................................................... 474 addulnk................................................................. 474 callw...................................................................... 475 movsf ..................................................................... 475 movss ..................................................................... 476 pushl ...................................................................... 476 subfsr ................................................................... 477 subulnk ................................................................. 477 external memory bus (emb)............................................. 121 16-bit byte write mode ............................................. 125 16-bit data width modes ....................................... ... 124 16-bit mode timing ......................................... .......... 128 16-bit word write mode............................................ 126 8-bit data width mode.............................................. 129 8-bit mode timing .......................................... ........... 130 address and data lines for different address and data widths (table) .................................... 123 address and data width .......................................... . 123 address shifting........................................................ 123 associated registers ................................................ 131 control ...................................................................... 122 i/o port functions ..................................................... 121 operation in power-managed modes ....................... 131 program memory modes .......................................... 124 extended microcontroller .................................. 124 microcontroller .................................................. 124 wait states................................................................ 124 weak pull-ups on port pins ...................................... 124 external memory bus emb) 16-bit byte select mode ........................................... 127 external oscillator modes clock input (ec modes).............................................. 51 hs ............................................................................... 50 f fail-safe clock monitor........................................ ..... 403, 424 exiting operation ...................................................... 424 interrupts in power-managed modes ........................ 425 por or wake from sleep ......................................... 425 wdt during oscillator failure .................................. 424 fast register stack............................................................. 91 firmware instructions........................................................ 431 flash program memory..................................................... 111 associated registers ................................................ 120 control registers ...................................................... 112 eecon1 and eecon2 .................................... 112 tablat (table latch) register........................ 114 tblptr (table pointer) register ..................... 114 tblptr (table pointer) register, boundaries.............................................. .. 114 erase sequence .............................................. ......... 116 erasing ..................................................................... 116 operation during code-protect ................................ 120 reading .................................................. .................. 115 table pointer boundaries based on operation ...................... 114 table reads and table writes ................................. 111 write sequence ............................................... ......... 118 writing ...................................................................... 117 protection against spurious writes .................. 120 unexpected termination .................................. 120 write verify ....................................................... 120 fscm. see fail-safe clock monitor. g goto ............................................................................... 452 h hardware multiplier........................................................... 139 8 x 8 multiplication algorithms .................................. 139 operation .................................................................. 139 performance comparison (table).............................. 139 high/low-voltage detect ............................................ ...... 379 applications .............................................................. 383 associated registers ................................................ 384 current consumption................................................ 381 effects of a reset ..................................................... 384 operation .................................................................. 380 during sleep..................................................... 384 setup ........................................................................ 381 start-up time ............................................................ 381 typical application.................................................... 383 hlvd. see high/low-voltage detect. i i/o ports............................................................................ 165 open-drain outputs................................................. . 167 output pin drive ....................................................... 165 pin capabilities ............................................. ............ 165 pull-up configuration ................................................ 165 i 2 c mode (mssp) acknowledge sequence timing ............................... 320 associated registers ................................................ 326 baud rate generator .............................................. . 313 bus collision during a repeated start condition................... 324 during a stop condition ................................... 325 clock arbitration ....................................................... 314 clock stretching........................................................ 306 10-bit slave receive mode (sen = 1) ............. 306 10-bit slave transmit mode ............................. 306 7-bit slave receive mode (sen = 1) ............... 306 7-bit slave transmit mode ............................... 306 clock synchronization and the ckp bit .................... 307 effects of a reset ..................................................... 321 general call address support .................................. 310 i 2 c clock rate w/brg.............................................. 313 master mode............................................................. 311 operation.......................................................... 312 reception ......................................................... 317 repeated start condition timing ..................... 316 start condition timing ...................................... 315 transmission .................................................... 317 transmit sequence .......................................... 312 multi-master communication, bus collision and arbitration ............................................. ..... 321 multi-master mode .................................................... 321 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 539 pic18f87k22 family operation .................................................................. 296 read/write bit information (r/w bit) ................ 296, 299 registers................................................................... 291 serial clock (rc3/sckx/sclx) ................................ 299 slave mode ............................................................... 296 address masking modes 5-bit .......................................................... 297 7-bit .......................................................... 298 addressing........................................................ 296 reception.......................................................... 299 transmission .................................................... 299 sleep operation ............................................... ......... 321 stop condition timing............................................... 320 id locations ............................................... ............... 403, 429 incf.................................................................................. 452 incfsz ............................................................................. 453 in-circuit debugger ........................................... ................ 429 in-circuit serial programming (icsp) ....................... 403, 429 indexed literal offset addressing and standard pic18 instructions .............................. 478 indexed literal offset mode ........................................ ...... 478 indirect addressing ........................................................... 106 infsnz ............................................................................. 453 initialization conditions for all registers ....................... 79C86 instruction cycle ................................................................. 92 clocking scheme ........................................................ 92 flow/pipelining............................................................ 92 instruction set ................................................................... 43 1 addlw ..................................................................... 437 addwf..................................................................... 437 addwf (indexed literal offset mode) ..................... 479 addwfc .................................................................. 438 andlw ..................................................................... 438 andwf..................................................................... 439 bc ............................................................................. 439 bcf........................................................................... 440 bn ............................................................................. 440 bnc .......................................................................... 441 bnn .......................................................................... 441 bnov........................................................................ 442 bnz........................................................................... 442 bov .......................................................................... 445 bra........................................................................... 443 bsf ........................................................................... 443 bsf (indexed literal offset mode) ........................... 479 btfsc ...................................................................... 444 btfss ...................................................................... 444 btg........................................................................... 445 bz ............................................................................. 446 call ......................................................................... 446 clrf......................................................................... 447 clrwdt................................................................... 447 comf ....................................................................... 448 cpfseq ................................................................... 448 cpfsgt ................................................................... 449 cpfslt .................................................................... 449 daw.......................................................................... 450 dcfsnz ................................................................... 451 decf ........................................................................ 450 decfsz.................................................................... 451 extended instructions ........................................ ....... 473 considerations when enabling ......................... 478 syntax .............................................................. 473 use with mplab ide tools.............................. 480 general format ............................................... ......... 433 goto ....................................................................... 452 incf ......................................................................... 452 incfsz..................................................................... 453 infsnz..................................................................... 453 iorlw...................................................................... 454 iorwf...................................................................... 454 lfsr ........................................................................ 455 movf ....................................................................... 455 movff ..................................................................... 456 movlb ..................................................................... 456 movlw .................................................................... 457 movwf.................................................................... 457 mullw..................................................................... 458 mulwf .................................................................... 458 negf........................................................................ 459 nop.......................................................................... 459 opcode field descriptions ....................................... 432 pop .......................................................................... 460 push........................................................................ 460 rcall ...................................................................... 461 reset...................................................................... 461 retfie..................................................................... 462 retlw ..................................................................... 462 return................................................................... 463 rlcf ........................................................................ 463 rlncf...................................................................... 464 rrcf....................................................... ................. 464 rrncf .................................................. ................... 465 setf ........................................................................ 465 setf (indexed literal offset mode) ......................... 479 sleep ...................................................................... 466 standard instructions.......................................... ...... 431 subfwb .................................................................. 466 sublw..................................................................... 467 subwf..................................................................... 467 subwfb .................................................................. 468 swapf..................................................................... 468 tblrd...................................................................... 469 tblwt ..................................................................... 470 tstfsz .................................................................... 471 xorlw .................................................................... 471 xorwf .................................................................... 472 intcon register rbif bit .................................................................... 172 inter-integrated circuit. see i 2 c. internal oscillator block ...................................................... 52 adjustment.................................................................. 53 intio modes ............................................. ................. 52 intosc frequency drift .............................................. ..... 53 output frequency............................................. .. 53 intpll modes............................................. ............... 52 internal rc oscillator use with wdt........................................................... 419 internal voltage regulator specifications......................... 500 internet address ............................................................... 547 downloaded from: http:///
pic18f87k22 family ds39960d-page 540 ? 2009-2011 microchip technology inc. interrupt sources............................................................... 4 03 a/d conversion complete ........................................ 361 capture complete (ccp).......................................... 251 capture complete (eccp) ....................................... 263 compare complete (ccp)........................................ 252 compare complete (eccp) ..................................... 264 interrupt-on-change (rb7:rb4) ............................... 172 tmr0 overflow ......................................................... 195 tmr1 overflow ......................................................... 202 tmr2 to pr2 match (pwm) ..................................... 255 tmrx overflow .............................................. ... 211, 221 interrupts ........................................................................... 141 associated registers ................................................ 164 during, context saving ............................................. 163 intx pin .................................................................... 163 portb, interrupt-on-change ................................... 163 tmr0 ........................................................................ 163 interrupts, flag bits interrupt-on-change (rb7:rb4) flag (rbif bit) ...... 172 intosc, intrc. see internal oscillator block. iorlw .............................................................................. 454 iorwf .............................................................................. 454 l lfsr ................................................................................. 455 m master clear (mclr ) .......................................................... 75 master synchronous serial port (mssp). see mssp. memory organization............................................ .............. 87 data memory .............................................................. 94 program memory maps .............................................. 87 memory programming requirements ............................... 499 microchip internet web site .............................................. 547 migration from pic18f87j11 and pic18f8722 to pic18f87k22 ....................................................... 534 movf................................................................................ 455 movff.............................................................................. 456 movlb.............................................................................. 456 movlw............................................................................. 457 movsf ............................................................................. 475 movss ............................................................................. 476 movwf ............................................................................ 457 mplab asm30 assembler, linker, librarian ................... 482 mplab integrated development environment software.................................................................... 481 mplab pm3 device programmer..................................... 484 mplab real ice in-circuit emulator system................. 483 mplink object linker/mplib object librarian ................ 482 mssp ack pulse................................................ ......... 296, 299 i 2 c mode. see i 2 c mode. module overview ................................................. ..... 281 spi master/slave connection ................................... 285 tmrx output for clock shift ..................................... 224 mullw ............................................................................. 458 mulwf ............................................................................. 458 n negf ................................................................................ 459 nop .................................................................................. 459 notable differences between pic18f87k22, pic18f87j11 and pic18f8722 families ........................................ 534 o on-chip voltage regulator ................................................ .................. 421 disable.............................................................. 421 enable ................................................. ............. 421 sleep ................................................................ 422 oscillator configuration ...................................................... 43 ec............................................................................... 43 ecio........................................................................... 43 hs............................................................................... 43 internal oscillator block .............................................. 52 intio1 ........................................................................ 43 intio2 ........................................................................ 43 lp ............................................................................... 43 rc .............................................................................. 43 rcio........................................................................... 43 xt ............................................................................... 43 oscillator selection ..................... ................................ ...... 403 oscillator start-up timer (ost) ...... .................................... 55 oscillator switching ...................... ...................................... 48 oscillator transitions .................... ...................................... 49 oscillator, timer1...................... ................................ ........ 197 oscillator, timer3/5/7.................. ................................ ...... 211 p p1a/p1b/p1c/p1d. see enhanced capture/compare/pwm (eccp). ............................. 265 packaging ......................................................................... 525 details....................................................................... 526 marking..................................................................... 525 parallel slave port (psp)................................................ .. 189 associated registers ................................................ 191 portd ..................................................................... 189 pin functions av dd ..................................................................... 23, 36 av ss ..................................................................... 23, 36 envreg .............................................................. 23, 36 mclr /rg5 ........................................................... 15, 24 osc1/clki/ra7 ................................................... 15, 24 osc2/clko/ra6 ................................................. 15, 24 ra0/an0/ulpwu................................................. 16, 25 ra1/an1............................................................... 16, 25 ra2/an2/v ref - .................................................... 16, 25 ra3/an3/v ref + ................................................... 16, 25 ra4/t0cki ........................................................... 16, 25 ra5/an4/t1cki/t3g/hlvdin ............................. 16, 25 rb0/int0/flt0........................................................... 26 rb0/int0/flto.......................................................... 17 rb1/int1 .............................................................. 17, 26 rb2/int2/cted1 ................................................. 17, 26 rb3/int3/cted2/eccp2/p2a ............................ 17, 26 rb4/kbi0 .............................................................. 17, 26 rb5/kbi1/t3cki/t1g........................................... 17, 26 rb6/kbi2/pgc ..................................................... 17, 26 rb7/kbi3/pgd ..................................................... 17, 26 rc0/sosco/sckli ................................................... 27 rc0/sosco/sclki ................................................... 18 rc1/sosci/eccp2/p2a...................................... 18, 27 rc2/eccp1/p1a.................................................. 18, 27 rc3/sck1/scl1 .................................................. 18, 27 rc4/sdi1/sda1 ................................................... 18, 27 rc5/sdo1............................................................ 18, 27 rc6/tx1/ck1 ....................................................... 18, 27 rc7/rx1/dt1....................................................... 18, 27 rd0/psp0/ctpls...................................................... 19 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 541 pic18f87k22 family rd0/psp0/ctpls/ad0 .............................................. 28 rd1/psp1/t5cki/t7g ............................................... 19 rd1/t5cki/t7g/psp1/ad1 ....................................... 28 rd2/psp2................................................................... 19 rd2/psp2/ad2........................................................... 28 rd3/psp3................................................................... 19 rd3/psp3/ad3........................................................... 28 rd4/psp4/sdo2........................................................ 19 rd4/sdo2/psp4/ad4................................................ 28 rd5/psp5/sdi2/sda2 ............................................... 19 rd5/sdi2/sda2/psp5/ad5 ....................................... 28 rd6/psp6/sck2/scl2 .............................................. 19 rd6/sck2/scl2/psp6/ad6 ...................................... 29 rd7/psp7/ss2 ........................................................... 19 rd7/ss2 /psp7/ad7................................................... 29 re0/p2d/rd /ad8....................................................... 30 re0/rd /p2d............................................................... 20 re1/p2c/wr /ad9 ...................................................... 30 re1/wr /p2c .............................................................. 20 re2/cs /p2b/ccp10................................................... 20 re2/p2b/ccp10/cs /ad10......................................... 30 re3/p3c/ccp9/refo ............................................... 20 re3/p3c/ccp9/refo/ad11 ..................................... 30 re4/p3b/ccp8........................................................... 20 re4/p3b/ccp8/ad12................................................. 30 re5/p1c/ccp7 .......................................................... 20 re5/p1c/ccp7/ad13 ................................................ 30 re6/p1b/ccp6........................................................... 20 re6/p1b/ccp6/ad14................................................. 31 re7/eccp2/p2a ........................................................ 20 re7/eccp2/p2a/ad15 .............................................. 31 rf1/an6/c2out/ctdin ...................................... 21, 32 rf2/an7/c1out .................................................. 21, 32 rf3/an8/c2inb/ctmui ....................................... 21, 32 rf4/an9/c2ina.................................................... 21, 32 rf5/an10/c1inb........................................................ 32 rf5/an10/cv ref /c1inb............................................ 21 rf6/an11/c1ina.................................................. 21, 32 rf7/an5/ss1 ....................................................... 21, 32 rg0/eccp3/p3a.................................................. 22, 33 rg1/tx2/ck2/an19/c3out................................ 22, 33 rg2/rx2/dt2/an18/c3ina ................................. 22, 33 rg3/ccp4/an17/p3d/c3inb .............................. 22, 33 rg4/rtcc/t7cki/t5g/ccp5/an16/ p1d/c3inc ................................................... 22, 33 rh0/an23/a16 ........................................................... 34 rh1/an22/a17 ........................................................... 34 rh2/an21/a18 ........................................................... 34 rh3/an20/a19 ........................................................... 34 rh4/ccp9/p3c/an12/c2inc .................................... 34 rh5/ccp8/p3b/an13/c2ind..................................... 34 rh6/ccp7/p1c/an14/c1inc .................................... 34 rh7/ccp6/p1b/an15 ................................................ 35 rj0/ale...................................................................... 36 rj1/oe ....................................................................... 36 rj2/wrl ..................................................................... 36 rj3/wrh .................................................................... 36 rj4/ba0...................................................................... 36 rj5/ce ........................................................................ 36 rj6/lb ........................................................................ 36 rj7/ub ........................................................................ 36 v dd ....................................................................... 23, 36 v ddcore /v cap ...................................................... 23, 36 v ss ........................................................................ 23, 36 pinout i/o descriptions pic18f6xk22............................................................. 15 pic18f8xk22............................................................. 24 pll ..................................................................................... 51 hspll and ecpll oscillator modes ......................... 51 use with hf-intosc ................................................. 51 pop .................................................................................. 460 por. see power-on reset. porta associated registers................................................ 171 lata register .......................................................... 170 porta register....................................................... 170 trisa register......................................................... 170 portb associated registers................................................ 173 latb register .......................................................... 172 portb register....................................................... 172 rb7:rb4 interrupt-on-change flag (rbif bit) ........ 172 trisb register......................................................... 172 portc associated registers................................................ 175 latc register .......................................................... 174 portc register....................................................... 174 rc3/sckx/sclx pin ................................................ 299 trisc register ........................................................ 174 portd associated registers................................................ 177 latd register .......................................................... 176 portd register....................................................... 176 trisd register ........................................................ 176 porte associated registers................................................ 180 late register .......................................................... 178 porte register....................................................... 178 re0/p2d/rd /ad8 pin .............................................. 189 re1/p2c/wr /ad9 pin ............................................. 189 re2/p2b/ccp10/cs /ad10 pin ................................ 189 trise register......................................................... 178 portf associated registers................................................ 182 latf register .......................................................... 181 portf register ....................................................... 181 trisf register......................................................... 181 portg associated registers................................................ 184 latg register.......................................................... 183 portg register ...................................................... 183 trisg register ........................................................ 183 porth associated registers................................................ 187 lath register .......................................................... 185 porth register....................................................... 185 trish register ........................................................ 185 portj associated registers................................................ 188 latj register........................................................... 187 portj register ....................................................... 187 trisj register ......................................................... 187 downloaded from: http:///
pic18f87k22 family ds39960d-page 542 ? 2009-2011 microchip technology inc. power-managed modes ........................................... ........... 57 and eusart operation............................................ 331 and pwm operation ........................................... ...... 279 and spi operation ............................................. ....... 289 clock transitions and status indicators...................... 58 entering....................................................................... 57 exiting idle and sleep modes ..................................... 69 by interrupt.......................................................... 69 by reset.............................................................. 69 by wdt time-out................................................ 69 without an oscillator start-up delay................... 69 idle modes ............................................... ................... 62 pri_idle ............................................................ 63 rc_idle............................................................. 64 sec_idle........................................................... 63 multiple sleep commands ......................................... . 58 run modes................................................. ................. 58 pri_run ............................................................ 58 rc_run ............................................................. 60 sec_run........................................................... 58 selecting ..................................................................... 5 7 sleep mode ............................................... .................. 62 osc1 and osc2 pin states ............................... 55 summary (table) ......................................................... 57 power-on reset (por) ....................................................... 75 power-up delays................................................................. 55 power-up timer (pwrt)............................................... 55, 76 time-out sequence............................................ ......... 76 prescaler, timer0.............................................................. 1 95 prescaler, timer2.............................................................. 2 56 pri_idle mode .................................................................. 63 pri_run mode ........................................................ .......... 58 program counter............................................. .................... 89 pcl, pch and pcu registers.................................... 89 pclath and pclatu registers ............................... 89 program memory code protection ............................................. ........... 427 extended instruction set ....................................... .... 107 hard memory vectors ................................................. 88 instructions.................................................................. 93 two-word ........................................................... 93 interrupt vector ........................................................... 88 look-up tables ................................................ ........... 91 memory maps ............................................................. 87 reset vector ............................................................... 88 program verification and code protection........................ 426 associated registers ................................................ 427 programming, device instructions .................................... 431 psp. see parallel slave port. pulse steering.............................................................. ..... 276 pulse-width modulation. see pwm (ccp module). push ................................................................................ 460 push and pop instructions ............................................... 90 pushl .............................................................................. 476 pwm (ccp module) associated registers ................................................ 256 duty cycle................................................................. 256 example frequencies/resolutions ........................... 256 period........................................................................ 255 setup for pwm operation......................................... 256 tmr2 to pr2 match ................................................. 255 pwm (eccp module) effects of a reset ..................................................... 279 operation in power-managed modes ....................... 279 operation with fail-safe clock monitor .................... 279 pulse steering mode ................................................ 276 steering synchronization.......................................... 278 pwm mode. see enhanced capture/compare/pwm. q q clock ............................................................................. 256 r ram. see data memory. rc_idle mode................................................................... 64 rc_run mode................................................ ................... 60 rcall .............................................................................. 461 rcon register bit status during initialization ..................................... 78 reader response................................................. ............ 548 real-time clock and calendar (rtcc) ........................... 227 registers .................................................................. 228 reference clock output ..................................................... 53 register file........................................................................ 96 register file summary ............................................ ... 98C103 registers adcon0 (a/d control 0).......................................... 352 adcon1 (a/d control 1).......................................... 353 adcon2 (a/d control 2).......................................... 354 adresh (a/d result high byte left justified, adfm = 0) ........................................................ 356 adresh (a/d result high byte right justified, adfm = 1) ....................................................... 357 adresl (a/d result high byte left justified, adfm = 0) ........................................................ 356 adresl (a/d result low byte right justified, adfm = 1) ........................................................ 357 alrmcfg (alarm configuration) ............................. 231 alrmday (alarm day value) .................................. 235 alrmhr (alarm hours value) ................................. 236 alrmmin (alarm minutes value)............................. 236 alrmmnth (alarm month value) ........................... 235 alrmrpt (alarm repeat) ....................................... 232 alrmsec (alarm seconds value) .......................... 236 alrmwd (alarm weekday value)........................... 235 ancon0 (a/d port configuration 0) ........................ 358 ancon1 (a/d port configuration 1) ........................ 358 ancon2 (a/d port configuration 2) ........................ 359 baudconx (baud rate control) ............................. 330 ccprxh (ccpx period high byte) .......................... 248 ccprxl (ccpx period low byte)............................ 248 ccptmrs0 (ccp timer select 0)........................... 261 ccptmrs1 (ccp timer select 1)........................... 246 ccptmrs2 (ccp timer select 2)........................... 247 ccpxcon (ccp4-ccp10 control) .......................... 245 ccpxcon (enhanced capture/compare/ pwmx control) ................................................. 260 cmstat (comparator status) ................................. 369 cmxcon (comparator control x)............................. 368 config1h (configuration 1 high) ........................... 406 config1l (configuration 1 low) ............................ 405 config2h (configuration 2 high) ........................... 408 config2l (configuration 2 low) ............................ 407 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 543 pic18f87k22 family config3h (configuration 3 high) ........................... 410 config3l (configuration 3 low)............................. 409 config4l (configuration 4 low)............................. 411 config5h (configuration 5 high) ........................... 413 config5l (configuration 5 low)............................. 412 config6h (configuration 6 high) ........................... 415 config6l (configuration 6 low)............................. 414 config7h (configuration 7 high) ........................... 417 config7l (configuration 7 low)............................. 416 ctmuconh (ctmu control high) .......................... 386 ctmuconl (ctmu control low)............................ 387 ctmuicon (ctmu current control) ....................... 388 cvrcon (comparator voltage reference control) ........................................... 375 day (day value)....................................................... 233 devid1 (device id 1) ............................................... 418 devid2 (device id 2) ............................................... 418 eccpxas (eccpx auto-shutdown control) ............ 273 eccpxdel (enhanced pwm control) ..................... 276 eecon1 (data eeprom control 1) ........................ 134 eecon1 (eeprom control 1)................................. 113 hlvdcon (high/low-voltage detect control)......... 379 hour (hour value) .................................................. 234 intcon (interrupt control)....................................... 143 intcon2 (interrupt control 2).................................. 144 intcon3 (interrupt control 3).................................. 145 ipr1 (peripheral interrupt priority 1)......................... 157 ipr2 (peripheral interrupt priority 2)......................... 158 ipr3 (peripheral interrupt priority 3)......................... 159 ipr4 (peripheral interrupt priority 4)......................... 159 ipr5 (peripheral interrupt priority 5)......................... 160 ipr6 (peripheral interrupt priority 6)......................... 161 memcon (external memory bus control) ............... 122 minute (minute value)............................................ 234 month (month value) ............................................. 233 odcon1 (peripheral open-drai n control 1)............ 167 odcon2 (peripheral open-drai n control 2)............ 168 odcon3 (peripheral open-drai n control 3)............ 169 osccon (oscillator control) ........ ............................. 45 osccon2 (oscillator control 2) ........................ 46, 214 osctune (oscillator tuning) .................................... 47 padcfg1 (pad configuration)......................... 166, 230 pie1 (peripheral interrupt enable 1)......................... 152 pie2 (peripheral interrupt enable 2)......................... 153 pie3 (peripheral interrupt enable 3)......................... 154 pie4 (peripheral interrupt enable 4)......................... 154 pie5 (peripheral interrupt enable 5)......................... 155 pie6 (peripheral interrupt enable 6)......................... 156 pir1 (peripheral interrupt request (flag) 1) ............ 146 pir2 (peripheral interrupt request (flag) 2) ............ 147 pir3 (peripheral interrupt request (flag) 3) ............ 148 pir4 (peripheral interrupt request (flag) 4) ............ 149 pir5 (peripheral interrupt request (flag) 5) ............ 150 pir6 (peripheral interrupt request (flag) 6) ............ 151 pmd0 (peripheral module disable 0) ......................... 68 pmd1 (peripheral module disable 1) ......................... 67 pmd2 (peripheral module disable 2) ......................... 66 pmd3 (peripheral module disable 3) ......................... 65 pspcon (parallel slave port control) ..................... 190 pstrxcon (pulse steering control) ....................... 277 rcon (reset control) ........................................ 74, 162 rcstax (receive status and control)..................... 329 refocon (reference oscillator control) ................. 54 reserved................................................................... 232 rtccal (rtcc calibration) .................................... 230 rtccfg (rtcc configuration)............................... 229 second (second value) ........................................ 234 sspxcon1 (msspx control 1, i 2 c mode) .............. 293 sspxcon1 (msspx control 1, spi mode).............. 283 sspxcon2 (msspx control 2, i 2 c master mode) ............................................. 294 sspxcon2 (msspx control 2, i 2 c slave mode) ............................................... 295 sspxmsk (i 2 c slave address mask, 7-bit masking mode)......................................... 295 sspxstat (msspx status, i 2 c mode).................... 292 sspxstat (msspx status, spi mode) ................... 282 status ................................................................... 104 stkptr (stack pointer)............................................. 90 t0con (timer0 control) .......................................... 193 t1con (timer1 control) .......................................... 197 t1gcon (timer1 gate control)............................... 198 t2con (timer2 control) .......................................... 209 txcon (timerx control, timer3/5/7) ....................... 212 txcon (timerx control, timer4/6/8/10/12) ............. 224 txgcon (timerx gate control) ............................... 213 txstax (transmit status and control) .................... 328 wdtcon (watchdog timer control) ....................... 420 weekday (weekday value) ................................... 233 year (year value)................................................... 232 reset.............................................................................. 461 reset .................................................................................. 73 brown-out reset (bor).............................................. 73 configuration mismatch (cm)..................................... 73 mclr , during power-managed modes...................... 73 mclr , normal operation ........................................... 73 power-on reset (por)............................................... 73 reset instruction ...................................................... 73 stack full.................................................................... 73 stack underflow ............................................. ............ 73 watchdog timer (wdt).......................................... .... 73 resets .............................................................................. 403 brown-out reset (bor)............................................ 403 oscillator start-up timer (ost)................................ 403 power-on reset (por)............................................. 403 power-up timer (pwrt) .......................................... 403 retfie ............................................................................. 462 retlw ............................................................................. 462 return........................................................................... 463 return address stack......................................................... 89 return stack pointer (stkptr) ......................................... 90 revision history................................................................ 533 rlcf ................................................................................ 463 rlncf.............................................................................. 464 rrcf........................................................... ..................... 464 rrncf .................................................. ........................... 465 rtcc alarm ........................................................................ 240 configuring ....................................................... 240 interrupt ............................................................ 241 mask settings ................................................... 241 alarm value registers (alrmvall, alrmvalh) ............................... 235 associated alarm value registers ........................... 243 associated control registers ................................... 2 43 associated value registers...................................... 243 control registers...................................................... 229 downloaded from: http:///
pic18f87k22 family ds39960d-page 544 ? 2009-2011 microchip technology inc. operation .................................................................. 237 calibration......................................................... 240 clock source..................................................... 238 digit carry rules............................................... 238 general functionality ........................................ 239 leap year ................................................. ........ 239 register mapping.............................................. 239 alrmval ................................................. 240 rtcval.................................................... 239 safety window for register reads and writes............................................... .. 239 write lock ......................................................... 239 register interface...................................................... 237 register maps........................................................... 243 reset......................................................................... 242 device ............................................................... 242 power-on reset (por) ..................................... 242 sleep mode ............................................... ................ 242 value registers (rtcval) ....................................... 232 rtcen bit write ............................................................... 2 37 s sckx ................................................................................. 281 sdix .................................................................................. 281 sdox................................................................................. 281 sec_idle mode................................................................. 63 sec_run mode ................................................ ................. 58 selective peripheral module control................................... 64 serial clock, sckx............................................................ 281 serial data in (sdix) ......................................................... 281 serial data out (sdox)..................................................... 281 serial peripheral interface. see spi mode. setf ................................................................................. 465 shoot-through current ............................................... ...... 275 slave select (ssx ) ............................................................ 281 sleep............................................................................... 466 software simulator (mplab sim)..................................... 483 special event trigger. see compare (ccp module). special event trigger. see compare (eccp mode). spi mode (mssp).......................................... ................... 281 associated registers ................................................ 290 bus mode compatibility ......................................... ... 289 clock speed, interactions ......................................... 289 effects of a reset...................................................... 289 enabling spi i/o ....................................................... 285 master mode ............................................................. 286 master/slave connection ....................................... ... 285 operation .................................................................. 284 operation in power-managed modes ....................... 289 serial clock............................................................... 281 serial data in ............................................................ 281 serial data out ......................................................... 281 slave mode ............................................................... 287 slave select .............................................................. 281 slave select synchronization ................................... 287 spi clock .................................................................. 286 sspxbuf register ................................................... 286 sspxsr register...................................................... 286 typical connection ................................................... 285 sspov.............................................................................. 317 sspov status flag........................................................... 317 sspxstat register r/w bit ................................................ .............. 296, 299 ssx ................................................................................... 281 stack full/underflow resets..................................... .......... 91 subfsr ........................................................................... 477 subfwb .......................................................................... 46 6 sublw ............................................................................. 467 subulnk......................................................................... 477 subwf............................................................................. 467 subwfb .......................................................................... 468 swapf ............................................................................. 468 t table pointer operations (table)....................................... 114 table reads/table writes ........................................... ....... 91 tblrd .............................................................................. 469 tblwt.............................................................................. 470 timer0............................................................................... 193 associated registers ................................................ 195 operation .................................................................. 194 overflow interrupt ..................................................... 195 prescaler .................................................................. 195 switching assignment ...................................... 195 prescaler assignment (psa bit) ............................... 195 prescaler select (t0ps2:t0ps0 bits) ...................... 195 reads and writes in 16-bit mode ............................. 194 source edge select (t0se bit) ................................ 194 source select (t0cs bit).......................................... 194 timer1............................................................................... 197 16-bit read/write mode ........................................... 201 associated registers ................................................ 207 clock source selection............................................. 199 gate .......................................................................... 203 interrupt .................................................................... 202 operation .................................................................. 199 oscillator............................. ................................ ...... 197 sosc layout considerations........................... 202 oscillator, as secondary clock.................................. . 48 resetting, using the eccp special event trigger .................................................... 203 sosc oscillator........................................................ 201 tmr1h register ....................................................... 197 tmr1l register........................................................ 197 using sosc as a clock source ............................... 202 timer2............................................................................... 209 associated registers ................................................ 210 interrupt .................................................................... 210 operation .................................................................. 209 output ....................................................................... 210 pr2 register ............................................................ 255 tmr2 to pr2 match interrupt................................... 255 timer3/5/7......................................................................... 211 16-bit read/write mode ........................................... 216 associated registers ................................................ 222 gates ........................................................................ 217 operation .................................................................. 215 oscillator............................. ................................ ...... 211 overflow interrupt .......................................... ... 211, 221 special event trigger (eccp) .................................. 221 tmrxh register ....................................................... 211 tmrxl register........................................................ 211 using sosco oscillator as clock source ............... 216 timer4 mssp clock shift ..................................................... 224 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 545 pic18f87k22 family timer4/6/8/10/12............................................................... 223 associated registers ................................................ 225 interrupt..................................................................... 224 operation .................................................................. 223 output ....................................................................... 224 postscaler. see postscaler, timer4/6/8/10/12. prescaler. see prescaler, timer4/6/8/10/12. prx register............................................................. 223 tmrx register .......................................................... 223 timing diagrams a/d conversion......................................................... 524 asynchronous reception .......................................... 341 asynchronous transmission..................................... 338 asynchronous transmission (back-to-back) ............ 338 automatic baud rate calculation ............................. 336 auto-wake-up bit (wue) during normal operation .......................................................... 343 auto-wake-up bit (wue) during sleep .................... 343 baud rate generator with clock arbitration ............. 314 brg overflow sequence.......................................... 336 brg reset due to sdax arbitration during start condition ............................................. ..... 323 brown-out reset (bor) ............................................ 509 bus collision during repeated start condition (case 1) ............................................................ 324 bus collision during repeated start condition (case 2) ............................................................ 324 bus collision during start condition (sclx = 0) ...... 323 bus collision during start condition (sdax only).... 322 bus collision during stop condition (case 1) .......... 325 bus collision during stop condition (case 2) .......... 325 bus collision for transmit and acknowledge............ 321 capture/compare/pwm............................................ 513 clko and i/o ............................................. .............. 505 clock synchronization .............................................. 307 clock/instruction cycle ............................................... 92 eusart synchronous transmission (master/slave) .................................................. 522 eusart/ausart synchronous receive (master/slave) .................................................. 522 example spi master mode (cke = 0) ...................... 514 example spi master mode (cke = 1) ...................... 515 example spi slave mode (cke = 0) ........................ 516 example spi slave mode (cke = 1) ........................ 517 external clock........................................................... 503 external memory bus for sleep (extended microcontroller mode) ............................... 128, 130 external memory bus for tblrd (extended microcontroller mode) ............................... 128, 130 fail-safe clock monitor (fscm) ............................... 425 first start bit timing ................................................. 315 full-bridge pwm output ........................................ ... 270 half-bridge pwm output .................................. 268, 275 high-voltage detect operation (vdirmag = 1)....... 383 hlvd characteristics................................................ 511 i 2 c acknowledge sequence ..................................... 320 i 2 c bus data ............................................................. 519 i 2 c bus start/stop bits.............................................. 518 i 2 c master mode (7 or 10-bit transmission) ............ 318 i 2 c master mode (7-bit reception)........................... 319 i 2 c slave mode (10-bit reception, sen = 0, admsk = 01001)............................................ .. 303 i 2 c slave mode (10-bit reception, sen = 0) ........... 304 i 2 c slave mode (10-bit reception, sen = 1) ........... 309 i 2 c slave mode (10-bit transmission)...................... 305 i 2 c slave mode (7-bit reception, sen = 0, admsk = 01011) ............................................ . 301 i 2 c slave mode (7-bit reception, sen = 0) ............. 300 i 2 c slave mode (7-bit reception, sen = 1) ............. 308 i 2 c slave mode (7-bit transmission) ....................... 302 i 2 c slave mode general call address sequence (7 or 10-bit addressing mode).......................... 310 i 2 c stop condition receive or transmit mode......... 320 low-voltage detect operation (vdirmag = 0) ....... 382 mssp i 2 c bus data ................................................. 520 mssp i 2 c bus start/stop bits .................................. 520 parallel slave port (psp) read................................ 191 parallel slave port (psp) write ................................ 190 program memory fetch (8-bit) ................................. 506 program memory read ............................................ 507 program memory write ............................................ 508 pwm auto-shutdown with auto-restart enabled (pxrsen = 1)................................................... 274 pwm auto-shutdown with firmware restart (pxrsen = 0)................................................... 274 pwm direction change ............................................ 271 pwm direction change at near 100% duty cycle ........................................................ 272 pwm output ............................................................. 255 pwm output (active-high) ....................................... 266 pwm output (active-low) ........................................ 267 repeated start condition ......................................... 316 reset, watchdog timer (wdt), oscillator start-up timer (ost) and power-up timer (pwrt) ...... 509 send break character sequence............................. 344 slave synchronization .............................................. 287 slow rise time (mclr tied to v dd , v dd rise > t pwrt )............................................. 77 spi mode (master mode) ......................................... 286 spi mode (slave mode, cke = 0) ............................ 288 spi mode (slave mode, cke = 1) ............................ 288 steering event at beginning of instruction (strsync = 1)................................................ 278 steering event at end of instruction (strsync = 0)................................................ 278 synchronous reception (master mode, sren) ....... 347 synchronous transmission ...................................... 345 synchronous transmission (through txen) ........... 346 time-out sequence on power-up (mclr not tied to v dd ), case 1.................................... 77 time-out sequence on power-up (mclr not tied to v dd ), case 2.................................... 77 time-out sequence on power-up (mclr tied to v dd , v dd rise t pwrt ) ........................... 76 timer pulse generation......................................... ... 242 timer0 and timer1 external clock ........................... 512 timer1 gate count enable mode............................. 204 timer1 gate single pulse mode............................... 206 timer1 gate single pulse/toggle combined mode ............................................... 207 timer1 gate toggle mode........................................ 205 timer3/5/7 gate count enable mode....................... 217 timer3/5/7 gate single pulse mode......................... 219 timer3/5/7 gate single pulse/toggle combined mode ............................................... 220 timer3/5/7 gate toggle mode.................................. 218 transition for entry to idle mode ................................ 63 transition for entry to sec_run mode ..................... 59 transition for entry to sleep mode ............................. 62 downloaded from: http:///
pic18f87k22 family ds39960d-page 546 ? 2009-2011 microchip technology inc. transition for two-speed start-up (intosc to hspll).......................................... 423 transition for wake from idle to run mode ................ 63 transition for wake from sleep (hspll).................... 62 transition from rc_run mode to pri_run mode ................................................ .. 61 transition from sec_run mode to pri_run mode (hspll) ................................... 59 transition to rc_run mode ...................................... 61 timing diagrams and specifications capture/compare/pwm requirements .................... 513 clko and i/o requirements ............................ 505, 507 eusart/ausart synchronous receive requirements................................................ .... 522 eusart/ausart synchronous transmission requirements................................................ .... 522 example spi mode requirements (master mode, cke = 0) ........................................................... 514 example spi mode requirements (master mode, cke = 1) ........................................................... 515 example spi mode requirements (slave mode, cke = 0) ........................................................... 516 example spi slave mode requirements (cke = 1) .......................................................... 517 external clock requirements ................................... 503 hlvd characteristics................................................ 511 i 2 c bus data requirements (slave mode) ............... 519 i 2 c bus start/stop bits requirements (slave mode).............................................. ....... 518 internal rc accuracy (intosc) ............................... 504 mssp i 2 c bus data requirements .......................... 521 mssp i 2 c bus start/stop bits requirements ........... 520 pll clock.................................................................. 504 program memory fetch requirements (8-bit)........... 506 program memory write requirements ..................... 508 reset, watchdog timer, oscillator start-up timer, power-up timer and brown-out reset requirements ......................................... 510 timer0 and timer1 external clock requirements .... 512 top-of-stack access ........................................................... 89 tstfsz............................................................................. 471 two-speed start-up ........................................... ....... 403, 423 ieso (config1h, internal/external oscillator switchover bit ................................................... 406 two-word instructions example cases........................................................... 93 txstax register brgh bit .................................................................. 331 u ultra low-power wake-up exit delay ................................................................... 71 overview..................................................................... 70 v voltage reference specifications..................................... 500 w watchdog timer (wdt).......................................... .. 403, 419 associated registers ................................................ 420 control register........................................................ 420 during oscillator failure ........................................... 424 programming considerations ................................... 419 wcol .................................................. ..... 315, 316, 317, 320 wcol status flag.................................... 315, 316, 317, 320 www address ................................................ ................. 547 www, on-line support ........................................... ............ 8 x xorlw............................................................................. 471 xorwf ............................................................................ 472 downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 547 pic18f87k22 family the microchip web site microchip provides online support via our www site at www.microchip.com . this web site is used as a means to make files and information easily available to customers. accessible by using your favorite internet browser, the web site contains the following information: product support C data sheets and errata, application notes and sample programs, design resources, users guides and hardware support documents, latest software releases and archived software general technical support C frequently asked questions (faq), technical support requests, online discussion groups, microchip consultant program member listing business of microchip C product selector and ordering guides, latest microchip press releases, listing of seminars and events, listings of microchip sales offices, distributors and factory representatives customer change notification service microchips customer notification service helps keep customers current on microchip products. subscribers will receive e-mail notification whenever there are changes, updates, revisions or errata related to a specified product family or development tool of interest. to register, access the microchip web site at www.microchip.com . under support, click on customer change notification and follow the registration instructions. customer support users of microchip products can receive assistance through several channels: distributor or representative local sales office field application engineer (fae) technical support development systems information line customers should contact their distributor, representative or field application engineer (fae) for support. local sales offices are also available to help customers. a listing of sales offices and locations is included in the back of this document. technical support is available through the web site at: http://microchip.com/support downloaded from: http:///
pic18f87k22 family ds39960d-page 548 ? 2009-2011 microchip technology inc. reader response it is our intention to provide you with the best documentation possible to ensure successful use of your microchip product. if you wish to provide your comments on organization, clarity, subject matter, and ways in whic h our documentation can better serve you, please fax your comments to the technical publications manager at (480) 792-4150. please list the following information, and use this outline to provide us with your comments about this docume nt. to: technical publications manager re: reader response total pages sent ________ from: name company address city / state / zip / country telephone: (_______) _________ - _________ application (optional): would you like a reply? y n device: literature number: questions: fax: (______) _________ - _________ ds39960d pic18f87k22 family 1. what are the best features of this document? 2. how does this document meet your hardware and software development needs? 3. do you find the organization of this document easy to follow? if not, why? 4. what additions to the document do you think would enhance the structure and subject? 5. what deletions from the document could be made without affecting the overall usefulness? 6. is there any incorrect or misleading information (what and where)? 7. how would you improve this document? downloaded from: http:///
? 2009-2011 microchip technology inc. ds39960d-page 549 pic18f87k22 family product identification system to order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office . part no. x /xx xxx pattern package temperature range device device (1,2) pic18f65k22, pic18f65k22t pic18f66k22, pic18f66k22t pic18f67k22, pic18f67k22t pic18f85k22, pic18f85k22t pic18f86k22, pic18f86k22t pic18f87k22, pic18f87k22t temperature range i = -40 ? c to +85 ? c (industrial) e=-40 ? c to +125 ? c (extended) package pt = tqfp (plastic thin quad flatpack) mr = qfn (plastic quad flat) pattern qtp, sqtp, code or special requirements (blank otherwise) examples: a) pic18f87k22-i/pt 301 = industrial temperature, tqfp package, qtp pattern #301. b) pic18f87k22t-i/pt = tape and reel, industrial temperature, tqfp package c) pic18f87k22t-e/pt = tape and reel, extended temperature, tqfp package note 1: f = standard voltage range 2: t = in tape and reel plcc and tqfp packages only 3: rsl = silicon revision a3 downloaded from: http:///
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