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? 2010-2011 microchip technology inc. preliminary ds41414c pic16(l)f1946/1947 data sheet 64-pin flash-based, 8-bit cmos microcontrollers with lcd driver and nanowatt xlp technology
ds41414c-page 2 preliminary ? 2010-2011 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in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates.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 buyer?s 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, appl ication maestro, 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 tec hnology 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. ? 2010-2011, microchip technology incorporated, printed in the u.s.a., all rights reserved. printed on recycled paper. isbn: 978-1-61341-240-4 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 mo st 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 produc ts in a manner outside the operating specifications contained in microchip?s 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 microchip?s 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 company?s 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 and analog products. in addition, microchip?s quality system for the design and manufacture of development systems is iso 9001:2000 certified.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 3 pic16(l)f1946/1947 devices included in this data sheet: high-performance risc cpu: ? only 49 instructions to learn: - all single-cycle instructions except branches ? operating speed: - dc ? 32 mhz oscillator/clock input - dc ? 125 ns instruction cycle ? up to 16k x 14 words of flash program memory ? up to 1024 bytes of data memory (ram) ? interrupt capability with automatic context saving ? 16-level deep hardware stack ? direct, indirect and relative addressing modes ? processor read access to program memory special microcontroller features: ? precision internal oscillator: - factory calibrated to 1%, typical - software selectable frequency range from 32 mhz to 31 khz ? power-saving sleep mode ? power-on reset (por) ? power-up timer (pwrt) and oscillator start-up timer (ost) ? brown-out reset (bor): - selectable between two trip points - disable in sleep option ? multiplexed master clear with pull-up/input pin ? programmable code protection ? high endurance flash/eeprom cell: - 100,000 write flash endurance - 1,000,000 write eeprom endurance - flash/data eeprom retention: > 40 years ? wide operating voltage range: - 1.8v-5.5v (pic16f1946/47) - 1.8v-3.6v (pic16lf1946/47) pic16lf1946/47 low-power features: ? standby current: - 60 na @ 1.8v, typical ? operating current: -7.0 ? a @ 32 khz, 1.8v, typical (pic16lf1946/47) -75 ? a @ 1 mhz, 1.8v, typical (pic16lf1946/47) ? timer1 oscillator current: - 600 na @ 32 khz, 1.8v, typical ? low-power watchdog timer current: - 500 na @ 1.8v, typical (pic16lf1946/47) peripheral features: ? up to 54 i/o pins and 1 input-only pin: - high-current source/sink for direct led drive - individually programmable interrupt-on-pin change pins - individually programmable weak pull-ups ? integrated lcd controller: - up to 184 segments - variable clock input - contrast control - internal voltage reference selections ? capacitive sensing (csm) module (mtouch tm ): - up to 16 selectable channels ? a/d converter: - 10-bit resolution and up to 14 channels - selectable 1.024/2.048/4.096v voltage reference ? timer0: 8-bit timer/counter with 8-bit programmable prescaler ? enhanced timer1: - dedicated low-power 32 khz oscillator driver - 16-bit timer/counter with prescaler - external gate input mode with toggle and single shot modes - interrupt-on-gate completion ? timer2, 4, 6: 8-bit timer/counter with 8-bit period register, prescaler and postscaler ? two capture, compare, pwm modules (ccp): - 16-bit capture, max. resolution 125 ns - 16-bit compare, max. resolution 125 ns - 10-bit pwm, max. frequency 31.25 khz ? three enhanced capture, compare, pwm modules (eccp): - 3 pwm time-base options - auto-shutdown and auto-restart - pwm steering - programmable dead-band delay ? pic16f1946 ? pic16f1947 ? pic16lf1946 ? pic16lf1947 64-pin flash-based, 8-bit cmos microcontrollers with lcd driver and nanowatt xlp technology
pic16(l)f1946/1947 ds41414c-page 4 preliminary ? 2010-2011 microchip technology inc. peripheral features (continued): ? two master synchronous serial ports (mssps) with spi and i 2 c tm with: - 7-bit address masking - smbus/pmbus tm compatibility - auto-wake-up on start ? two enhanced universal synchronous: asynchronous receiver transmitters (eusarts) - rs-232, rs-485 and lin compatible - auto-baud detect ? sr latch (555 timer): - multiple set/reset input options - emulates 555 timer applications ? 2 comparators: - rail-to-rail inputs/outputs - power mode control - software enable hysteresis ? voltage reference module: - fixed voltage reference (fvr) with 1.024v, 2.048v and 4.096v output levels - 5-bit rail-to-rail resistive dac with positive and negative reference selection pic16f/lf1946/47 family types device program memory flash (words) data eeprom (bytes) sram (bytes) i/o?s 10-bit a/d (ch) capsense (ch) comparators timers 8/16-bit eusart i 2 c?/spi eccp ccp lcd pic16f1946 pic16lf1946 8192 256 512 54 17 17 3 4/1 2232184/4 pic16f1947 pic16lf1947 16384 256 1024 54 17 17 3 4/1 2232 184/4
? 2010-2011 microchip technology inc. preliminary ds41414c-page 5 pic16(l)f1946/1947 pin diagram ? 64-pin tqfp/qfn ( pic16(l)f1946/1947) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 38 37 36 35 34 33 50 49 17 18 19 20 21 22 23 24 25 26 re2/p2b (1) /vlcd3 re3/p3c (1) /com0 re4/p3b (1) /com1 re5/p1c (1) /com2 re6/p1b (1) /com3 re7/ccp2 (2) /p2a (2) /seg31 rd0/p2d (2) /seg0 v dd v ss rd1/p2c (2) /seg1 rd2/p2b (2) /seg2 rd3/p3c (2) /seg3 rd4/sdo2/p3b (2) /seg4 rd5/sdi2/sda2/p1c (2) /seg5 rd6/sck2/scl2/p1b (2) /seg6 rd7/ss2 /seg7 vlcd2/p2c (1) /re1 vlcd1/p2d (1) /re0 seg42/p3a/ccp3/rg0 seg43/c3out/ck2/tx2/cps15/an15/rg1 seg44/c3in+/dt2/rx2/cps14/an14/rg2 seg45/p3d/ccp4/c3in0-/cps13/an13/rg3 v pp /mclr /rg5 seg26/p1d/ccp5/c3in1-/cps12/an12/rg4 v ss v dd seg25/ss1 /c1in3-/c2in3-/c3in3-/cps5/an5/rf7 seg24/c1in+/cps11/an11/rf6 seg23/dacout/c1in1-/c2in1-/cps10/an10/rf5 seg22/c2in+/cps9/an9/rf4 seg21/c1in2-/c2in2-/c3in2-/cps8/an8/rf3 seg20/srq/c1out/cps7/an7/rf2 rb0/int/sri/flt0/seg30 rb1/seg8 rb2/seg9 rb3/seg10 rb4/seg11 rb5/t1g/seg29 rb6/icspclk/icdclk/seg38 v ss ra6/osc2/clkout/seg36 ra7/osc1/clkin/seg37 v dd rb7/icspdat/icddat/seg39 rc4/sdi1/sda1/seg16 rc3/sck1/scl1/seg17 rc2/ccp1/p1a/seg13 v cap /seg41/c1in0-/c2in0-/cps16/an16/rf0 seg19/srnq/c2out/cps6/an6/rf1 av dd av ss seg35/cps3/v ref +/an3/ra3 seg34/cps2/v ref -/an2/ra2 seg18/cps1/an1/ra1 seg33/cps0/an0/ra0 v ss v dd seg14/t0cki/ra4 seg15/cps4/an4/ra5 seg32/ccp2 (1) /p2a (1) / /t1osi/rc1 seg40/t1cki/t1oso/rc0 seg28/dt1/rx1/rc7 seg27/ck1/tx1/rc6 rc5/sdo1/seg12 15 16 31 40 39 27 28 29 30 32 48 47 46 45 44 43 42 41 54 53 52 51 58 57 56 55 60 59 64 63 62 61 64-pin tqfp, qfn note 1: pin location selected by apfcon register setting. default location. 2: pin function can be moved using the apfcon register. alternate location. 3: qfn package orientation is the same. no leads are present on the qfn package. pic16(l)f1946/1947
pic16(l)f1946/1947 ds41414c-page 6 preliminary ? 2010-2011 microchip technology inc. table 1: 64-pin summary(pic16(l)f1946/1947) i/o 64-pin tqfp, qfn ansel a/d reference cap sense comparator sr latch timers ccp usart mssp lcd interrupt pull-up basic ra0 24 y an0 ? cps0 ? ? ? ? ? ? seg33 ? ? ? ra1 23 y an1 ? cps1 ? ? ? ? ? ? seg18 ? ? ? ra2 22 y an2 v ref - cps2 ? ? ? ? ? ? seg34 ? ? ? ra3 21 y an3 v ref + cps3 ? ? ? ? ? ? seg35 ? ? ? ra4 28 ? ? ? ? ? ? t0cki ? ? ? seg14 ? ? ? ra5 27 y an4 ? cps4 ? ? ? ? ? ? seg15 ? ? ? ra6 40 ? ? ? ? ? ? ? ? ? ? seg36 ? ? osc2/ clk- out ra739??? ???? ? ??seg37??osc1/ clkin rb0 48 ? ? ? ? ? sri ? flt0 ? ? seg30 int/ ioc y ? rb147??? ???? ? ??seg8iocy ? rb2 46 ? ? ? ? ? ? ? ? ? ? seg9 ioc y ? rb345??? ???? ? ??seg10iocy ? rb4 44 ? ? ? ? ? ? ? ? ? ? seg11 ioc y ? rb543??? ???t1g? ??seg29iocy ? rb6 42 ? ? ? ? ? ? ? ? ? ? seg38 ioc y icsp- clk/ icdclk rb7 37 ? ? ? ? ? ? ? ? ? ? seg39 ioc y icsp- dat/ icddat rc0 30 ? ? ? ? ? ? t1oso/ t1cki ? ? ? seg40 ? ? ? rc1 29 ? ? ? ? ? ? t1osi ccp2 (1) / p2a (1) ? ? seg32 ? ? ? rc2 33 ? ? ? ? ? ? ? ccp1 / p1a ? ? seg13 ? ? ? rc334?????????sck1/ scl1 seg17 ? ? ? rc4 35 ? ? ? ? ? ? ? ? ? sdi1/ sda1 seg16 ? ? ? rc536??? ???? ? ?sdo1seg12??? rc6 31 ? ? ? ? ? ? ? ? tx1/ ck1 ? seg27 ? ? ? rc732??? ???? ?rx1/ dt1 ? seg28 ? ? ? rd0 58 ? ? ? ? ? ? ? p2d (2) ? ? seg0 ? ? ? rd155??? ????p2c (2) ? ? seg1 ? ? ? rd2 54 ? ? ? ? ? ? ? p2b (2) ? ? seg2 ? ? ? rd353??? ???? p3c (2) ? ? seg3 ? ? ? rd4 52 ? ? ? ? ? ? ? p3b (2) ? sdo2 seg4 ? ? ? rd551??? ????p1c (2) ?sdi2 sda2 seg5 ? ? ? rd6 50 ? ? ? ? ? ? ? p1b (2) ? sck2/ scl2 seg6 ? ? ? note 1: pin functions can be moved using the apfcon register(s). default location. 2: pin function can be moved using the apfcon register. alternate location. 3: weak pull-up always enabled when mclr is enabled, otherwise the pu ll-up is under user control. 4: see section 8.0 ?low dropout (ldo) voltage regulator? .
? 2010-2011 microchip technology inc. preliminary ds41414c-page 7 pic16(l)f1946/1947 rd749?????????ss2 seg7 ? ? ? re0 2 y ? ? ? ? ? ? p2d (1) ? vlcd1 ? ? ? re11y?? ????p2c (1) ??vlcd2??? re2 64 y ? ? ? ? ? ? p2b (1) ? ? vlcd3 ? ? ? re363??? ????p3c (1) ??com0??? re4 62 ? ? ? ? ? ? ? p3b (1) ? ? com1 ? ? ? re561??? ????p1c (1) ??com2??? re6 60 ? ? ? ? ? ? ? p1b (1) ? ? com3 ? ? ? re759??? ???? ccp2 (2) / p2a (2) ? ? seg31 ? ? ? rf0 18 y an16 ? cps16 c1in0- c2in0- ? ? ? ? ? seg41 ? ? v cap (3) rf1 17 y an6 ? cps6 c2out srnq ? ? ? ? seg19 ? ? ? rf2 16 y an7 ? cps7 c1out srq ? ? ? ? seg20 ? ? ? rf3 15 y an8 cps8 c1in2- c2in2- c3in2- ?? ? ??seg21??? rf4 14 y an9 ? cps9 c2in+ ? ? ? ? ? seg22 ? ? ? rf5 13 y an10 dacout cps10 c1in1- c2in1- ? ? ? ? seg23 ? ? ? rf6 12 y an11 ? cps11 c1in+ ? ? ? ? ? seg24 ? ? ? rf7 11 y an5 ? cps5 c1in3- c2in3- c3in3- ????ss1 seg25 ? ? ? rg0 3 ? ? ? ? ? ? ? ccp3 p3a ? ? seg42 ? ? ? rg1 4 y an15 ? cps15 c3out ? ? ? tx2/ ck2 ? seg43 ? ? ? rg2 5 y an14 ? cps14 c3in+ ? ? ? rx2/ dt2 ? seg44 ? ? ? rg3 6 y an13 ? cps13 c3in0- ? ? ccp4 p3d ?? seg45 ??? rg4 8 y an12 ? cps12 c3in1- ? ? ccp5 p1d ? ? seg26 ? ? ? rg57???????????? y (2) mclr / v pp v dd 10 26 38 57 ? ? ? ? ? ? ? ? ? ? ? ? ? v dd v ss 9 25 41 56 ??? ???? ? ?????v ss av dd 19 ? ? ? ? ? ? ? ? ? ? ? ? ? av dd av ss 20??? ???? ? ?????av ss table 1: 64-pin summary(pic16(l)f1946/1947) (continued) i/o 64-pin tqfp, qfn ansel a/d reference cap sense comparator sr latch timers ccp usart mssp lcd interrupt pull-up basic note 1: pin functions can be moved using the apfcon register(s). default location. 2: pin function can be moved using the apfcon register. alternate location. 3: weak pull-up always enabled when mclr is enabled, otherwise the pu ll-up is under user control. 4: see section 8.0 ?low dropout (ldo) voltage regulator? .
pic16(l)f1946/1947 ds41414c-page 8 preliminary ? 2010-2011 microchip technology inc. table of contents 1.0 device overview ............................................................................................................. ........................................................... 11 2.0 enhanced mid-range cpu ...................................................................................................... .................................................. 19 3.0 memory organization ......................................................................................................... ........................................................ 21 4.0 device configuration ........................................................................................................ .......................................................... 55 5.0 oscillator module (with fail-safe clock monitor)............................................................................ ........................................... 61 6.0 resets ...................................................................................................................... .................................................................. 79 7.0 interrupts .................................................................................................................. .................................................................. 87 8.0 low dropout (ldo) voltage regulator ......................................................................................... ........................................... 103 9.0 power-down mode (sleep) ..................................................................................................... ................................................. 105 10.0 watchdog timer ............................................................................................................. .......................................................... 107 11.0 data eeprom and flash program memory control ............................................................................... ................................ 111 12.0 i/o ports .................................................................................................................. ................................................................. 125 13.0 interrupt-on-change ........................................................................................................ ........................................................ 151 14.0 fixed voltage reference (fvr) .............................................................................................. ................................................. 155 15.0 temperature indicator module ............................................................................................... .................................................. 157 16.0 analog-to-digital converter (adc) module ................................................................................... ........................................... 159 17.0 digital-to-analog converter (dac) module ................................................................................... ........................................... 173 18.0 comparator module.......................................................................................................... ........................................................ 177 19.0 sr latch................................................................................................................... ................................................................ 187 20.0 timer0 module .............................................................................................................. ........................................................... 193 21.0 timer1 module with gate control............................................................................................ ................................................. 197 22.0 timer2/4/6 modules......................................................................................................... ......................................................... 209 23.0 capture/compare/pwm modules ................................................................................................ ............................................ 213 24.0 master synchronous serial port (mssp1 and mssp2) module .................................................................... .......................... 241 25.0 enhanced universal synchronous asynchronous receiver transmitter (eusart) .................................................. ............. 297 26.0 capacitive sensing (cps) module ............................................................................................ ............................................... 327 27.0 liquid crystal display (lcd) driver module ................................................................................. ............................................ 335 28.0 in-circuit serial programming? (icsp?) ..................................................................................... .......................................... 371 29.0 instruction set summary .................................................................................................... ...................................................... 375 30.0 electrical specifications.................................................................................................. .......................................................... 389 31.0 dc and ac characteristics graphs and charts ................................................................................ ....................................... 423 32.0 development support........................................................................................................ ....................................................... 425 33.0 packaging information...................................................................................................... ........................................................ 429 appendix a: data sheet revision history........................................................................................ .................................................. 435 appendix b: migrating from other pic ? devices....................................................................................................................... ....... 435 index .......................................................................................................................... ........................................................................ 437 the microchip web site ......................................................................................................... ............................................................ 445 customer change notification service ........................................................................................... ................................................... 445 customer support ............................................................................................................... ............................................................... 445 reader response ................................................................................................................ .............................................................. 446 product identification system.................................................................................................. ........................................................... 447
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pic16(l)f1946/1947 ds41414c-page 10 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 11 pic16(l)f1946/1947 1.0 device overview the pic16(l)f1946/1947 are described within this data sheet. they are available in 64-pin packages. figure 1-1 shows a block diagram of the pic16(l)f1946/1947 devices. ta b l e 1 - 2 shows the pinout descriptions. reference tab l e 1 - 1 for peripherals available per device. table 1-1: device peripheral summary peripheral pic16f1946/47 pic16lf1946/47 adc capacitive sensing (cps) module data eeprom digital-to-analog converter (dac) fixed voltage reference (fvr) lcd sr latch capture/compare/pwm modules eccp1 eccp2 eccp3 ccp4 ccp5 comparators c1 c2 c3 eusarts eusart1 eusart2 master synchronous serial ports mssp1 mssp2 timers timer0 timer1 timer2 timer4 timer6
pic16(l)f1946/1947 ds41414c-page 12 preliminary ? 2010-2011 microchip technology inc. figure 1-1: pic16(l)f1946/1947 block diagram porta eusartx comparators msspx timer2 timer1 timer4 timer0 eccp1 adc 10-bit eccp2 eccp3 ccp4 ccp5 timer6 portb portc portd porte lcd sr latch note 1: see applicable chapters for more information on peripherals. cpu program flash memory eeprom ram timing generation intrc oscillator mclr figure 2-1 osc1/clkin osc2/clkout portf portg
? 2010-2011 microchip technology inc. preliminary ds41414c-page 13 pic16(l)f1946/1947 table 1-2: pic16(l)f1946/1947 pinout description name function input type output type description ra0/an0/cps0/seg33 ra0 ttl cmos general purpose i/o. an0 an ? a/d channel 0 input. cps0 an ? capacitive sensing input 0. seg33 ? an lcd analog output. ra1/an1/cps1/seg18 ra1 ttl cmos general purpose i/o. an1 an ? a/d channel 1 input. cps1 an ? capacitive sensing input 1. seg18 ? an lcd analog output. ra2/an2/v ref -/cps2/seg34 ra2 ttl cmos general purpose i/o. an2 an ? a/d channel 2 input. v ref - an ? a/d negative voltage reference input. cps2 an ? capacitive sensing input 2. seg34 ? an lcd analog output. ra3/an3/v ref +/cps3/seg35 ra3 ttl cmos general purpose i/o. an3 an ? a/d channel 3 input. v ref + an ? a/d voltage reference input. cps3 an ? capacitive sensing input 3. seg35 ? an lcd analog output. ra4/t0cki/seg14 ra4 ttl cmos general purpose i/o. t0cki st ? timer0 clock input. seg14 ? an lcd analog output. ra5/an4/cps4/seg15 ra5 ttl cmos general purpose i/o. an4 an ? a/d channel 4 input. cps4 an ? capacitive sensing input 4. seg5 ? an lcd analog output. ra6/osc2/clkout/seg36 ra6 ttl cmos general purpose i/o. osc2 ? xtal crystal/resonator (lp, xt, hs modes). clkout ? cmos f osc /4 output. seg36 ? an lcd analog output. ra7/osc1/clkin/seg37 ra7 ttl cmos general purpose i/o. osc1 xtal ? crystal/resonator (lp, xt, hs modes). clkin cmos ? external clock input (ec mode). seg37 ? an lcd analog output. rb0/int/sri/flt0/seg30 rb0 ttl cmos general purpose i/o. individually controlled interrupt-on-change. individually enabled pull-up. int st ? external interrupt. sri ? st sr latch input. flt0 st ? eccp auto-shutdown fault input. seg30 ? an lcd analog output. rb1/seg8 rb1 ttl cmos general purpose i/o. i ndividually controlled interrupt-on-change. individually enabled pull-up. seg8 ? an lcd analog output. legend: an = analog input or output cmos = cmos compatible input or output od = open drain ttl = ttl compatible input st = schmitt trigger input with cmos levels i 2 c? = schmitt trigger input with i 2 c hv = high voltage xtal = crystal levels note 1: pin function is selectable via the apfcon register.
pic16(l)f1946/1947 ds41414c-page 14 preliminary ? 2010-2011 microchip technology inc. rb2/seg9 rb2 ttl cmos general purpose i/o. i ndividually controlled interrupt-on-change. individually enabled pull-up. seg9 ? an lcd analog output. rb3/seg10 rb3 ttl cmos general purpose i/o. i ndividually controlled interrupt-on-change. individually enabled pull-up. seg10 ? an lcd analog output. rb4/seg11 rb4 ttl cmos general purpose i/o. i ndividually controlled interrupt-on-change. individually enabled pull-up. seg11 ? an lcd analog output. rb5/t1g/seg29 rb5 ttl cmos general purpose i/o. individually controlled interrupt-on-change. individually enabled pull-up. t1g st ? timer1 gate input. seg29 ? an lcd analog output. rb6/icspclk/icdclk/seg38 rb6 ttl cmos general purpose i /o. individually controlled interrupt-on-change. individually enabled pull-up. icspclk st ? serial programming clock. icdclk st ? in-circuit debug clock. seg38 ? an lcd analog output. rb7/icspdat/icddat/seg39 rb7 ttl cmos general purpose i /o. individually controlled interrupt-on-change. individually enabled pull-up. icspdat st cmos icsp? data i/o. icddat st cmos in-circuit data i/o. seg39 ? an lcd analog output. rc0/t1oso/t1cki/seg40 rc0 st cmos general purpose i/o. t1oso xtal xtal timer1 oscillator connection. t1cki st ? timer1 clock input. seg40 ? an lcd analog output. rc1/t1osi/p2a (1) /ccp2 (1) / seg32 rc1 st cmos general purpose i/o. t1osi xtal xtal timer1 oscillator connection. p2a ? cmos pwm output. ccp2 st cmos capture/compare/pwm2. seg32 ? an lcd analog output. rc2/ccp1/p1a/seg13 rc2 st cmos general purpose i/o. ccp1 st cmos capture/compare/pwm1. p1a ? cmos pwm output. seg13 ? an lcd analog output. rc3/sck/scl/seg17 rc3 st cmos general purpose i/o. sck st cmos spi clock. scl i 2 codi 2 c? clock. seg17 ? an lcd analog output. rc4/sdi1/sda1/seg16 rc4 st cmos general purpose i/o. sdi1 st ? spi data input. sda1 i 2 codi 2 c? data input/output. seg16 ? an lcd analog output. table 1-2: pic16(l)f1946/1947 pinout description (continued) name function input type output type description legend: an = analog input or output cmos = cmos compatible input or output od = open drain ttl = ttl compatible input st = schmitt trigger input with cmos levels i 2 c? = schmitt trigger input with i 2 c hv = high voltage xtal = crystal levels note 1: pin function is selectable via the apfcon register.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 15 pic16(l)f1946/1947 rc5/sdo1/seg12 rc5 st cmos general purpose i/o. sdo1 ? cmos spi data output. seg12 ? an lcd analog output. rc6/tx1/ck1/seg27 rc6 st cmos general purpose i/o. tx1 ? cmos usart1 asynchronous transmit. ck1 st cmos usart1 synchronous clock. seg27 ? an lcd analog output. rc7/rx1/dt1/seg28 rc7 st cmos general purpose i/o. rx st ? usart1 asynchronous input. dt1 st cmos usart1 synchronous data. seg28 ? an lcd analog output. rd0/p2d (1) /seg0 rd0 st cmos general purpose i/o. p2d ? cmos pwm output. seg0 ? an lcd analog output. rd1/p2c (1) /seg1 rd1 st cmos general purpose i/o. p2c ? cmos pwm output. seg1 ? an lcd analog output. rd2/p2b (1) /seg2 rd2 st cmos general purpose i/o. p2b ? cmos pwm output. seg2 ? an lcd analog output. rd3/p3c (1) /seg3 rd3 st cmos general purpose i/o. p3c ? cmos pwm output. seg3 ? an lcd analog output. rd4/sdo2/p3b (1) /seg4 rd4 st cmos general purpose i/o. sdo2 ? cmos spi data output. p3b ? cmos pwm output. seg4 ? an lcd analog output. rd5/sdi2/sda2/p1c (1) /seg5 rd5 st cmos general purpose i/o. sdi2 st ? spi data input. sda2 i 2 codi 2 c? data input/output. p1c ? cmos pwm output. seg5 ? an lcd analog output. rd6/sck2/scl2/p1b (1) /seg6 rd6 st cmos general purpose i/o. sck2 st cmos spi clock. scl2 i 2 codi 2 c? clock. p1b ? cmos pwm output. seg6 ? an lcd analog output. rd7/ss2 /seg7 rd7 st cmos general purpose i/o. ss2 st ? slave select input. seg7 ? an lcd analog output. re0/p2d (1) /vlcd1 re0 st cmos general purpose i/o. p2d ? cmos pwm output. vlcd1 an ? lcd analog input. table 1-2: pic16(l)f1946/1947 pinout description (continued) name function input type output type description legend: an = analog input or output cmos = cmos compatible input or output od = open drain ttl = ttl compatible input st = schmitt trigger input with cmos levels i 2 c? = schmitt trigger input with i 2 c hv = high voltage xtal = crystal levels note 1: pin function is selectable via the apfcon register.
pic16(l)f1946/1947 ds41414c-page 16 preliminary ? 2010-2011 microchip technology inc. re1/p2c (1) /vlcd2 re1 st cmos general purpose i/o. p2c ? cmos pwm output. vlcd2 an ? lcd analog input. re2/p2b (1) /vlcd3 re2 st cmos general purpose i/o. p2b ? cmos pwm output. vlcd3 an ? lcd analog input. re3/p3c (1) /com0 re3 ttl ? general purpose input. p3c ? cmos pwm output. com0 ? an lcd analog output. re4/p3b (1) /com1 re4 ttl ? general purpose input. p3b ? cmos pwm output. com1 ? an lcd analog output. re5/p1c (1) /com2 re5 ttl ? general purpose input. p1c ? cmos pwm output. com2 ? an lcd analog output. re6/p1b (1) /com3 re6 ttl ? general purpose input. p1b ? cmos pwm output. com3 ? an lcd analog output. re7/ccp2 (1) /p2a (1) /seg31 re7 ttl ? general purpose input. ccp2 st cmos capture/compare/pwm2. p2a ? cmos pwm output. seg31 ? an lcd analog output. rf0/an16/cps16/c12in0-/ seg41/v cap rf0 ttl cmos general purpose i/o. an16 an ? a/d channel 16 input. cps16 an ? capacitive sensing input 16. c1in0- an ? comparator c1 negative input. c2in0- an ? comparator c2 negative input. seg41 ? an lcd analog output. v cap power power filter capacitor for voltage regulator. rf1/an6/cps6/c2out/srnq/ seg19 rf1 ttl cmos general purpose i/o. an6 an ? a/d channel 6 input. cps6 an ? capacitive sensing input 6. c2out ? cmos comparator c2 output. srnq ? cmos sr latch inverting output. seg19 ? an lcd analog output. rf2/an7/cps7/c1out/srq/ seg20 rf2 ttl cmos general purpose i/o. an7 an ? a/d channel 7 input. cps7 an ? capacitive sensing input 7. c1out ? cmos comparator c1 output. srq ? cmos sr latch non-inverting output. seg20 ? an lcd analog output. table 1-2: pic16(l)f1946/1947 pinout description (continued) name function input type output type description legend: an = analog input or output cmos = cmos compatible input or output od = open drain ttl = ttl compatible input st = schmitt trigger input with cmos levels i 2 c? = schmitt trigger input with i 2 c hv = high voltage xtal = crystal levels note 1: pin function is selectable via the apfcon register.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 17 pic16(l)f1946/1947 rf3/an8/cps8/c123in2-/ seg21 rf3 ttl cmos general purpose i/o. an8 an ? a/d channel 8 input. cps8 an ? capacitive sensing input 8. c1in2- an ? comparator c1 negative input. c2in2- an ? comparator c2 negative input. c3in2- an ? comparator c3 negative input. seg21 ? an lcd analog output. rf4/an9/cps9/c2in+/seg22 rf4 ttl cmos general purpose i/o. an9 an ? a/d channel 9 input. cps9 an ? capacitive sensing input 9. c2in+ an ? comparator c2 positive input. seg22 ? an lcd analog output. rf5/an10/cps10/c12in1-/ dacout/seg23 rf5 ttl cmos general purpose i/o. an10 an ? a/d channel 10 input. cps10 an ? capacitive sensing input 10. c1in1- an ? comparator c1 negative input. c2in1- an ? comparator c2 negative input. dacout ? an voltage reference output. seg23 ? an lcd analog output. rf6/an11/cps11/c1in+/seg24 rf6 ttl cmos general purpose i/o. an11 an ? a/d channel 11 input. cps11 an ? capacitive sensing input 11. c1in+ an ? comparator c1 positive input. seg24 ? an lcd analog output. rf7/an5/cps5/c123in3-/ss1 / seg25 rf7 ttl cmos general purpose i/o. an5 an ? a/d channel 5 input. cps5 an ? capacitive sensing input 5. c1in3- an ? comparator c1negative input. c2in3- an ? comparator c2 negative input. c3in3- an ? comparator c3 negative input. ss1 st ? slave select input. seg25 ? an lcd analog output. rg0/ccp3/p3a/seg42 rg0 st cmos general purpose i/o. ccp3 st cmos capture/compare/pwm3. p3a ? cmos pwm output. seg42 ? an lcd analog output. rg1/an15/cps15/tx2/ck2/ c3out/seg43 rg1 st cmos general purpose i/o. an15 an ? a/d channel 15 input. cps15 an ? capacitive sensing input 15. tx2 ? cmos usart2 asynchronous transmit. ck2 st cmos usart2 synchronous clock. c3out ? cmos comparator c3 output. seg43 ? an lcd analog output. table 1-2: pic16(l)f1946/1947 pinout description (continued) name function input type output type description legend: an = analog input or output cmos = cmos compatible input or output od = open drain ttl = ttl compatible input st = schmitt trigger input with cmos levels i 2 c? = schmitt trigger input with i 2 c hv = high voltage xtal = crystal levels note 1: pin function is selectable via the apfcon register.
pic16(l)f1946/1947 ds41414c-page 18 preliminary ? 2010-2011 microchip technology inc. rg2/an14/cps14/rx2/dt2/ c3in+/seg44 rg2 st cmos general purpose i/o. an14 an ? a/d channel 14 input. cps14 an ? capacitive sensing input 14. rx2 st ? usart2 asynchronous input. dt2 st cmos usart2 synchronous data. c3in+ an ? comparator c3 positive input. seg44 ? an lcd analog output. rg3/an13/cps13/c3in0-/ ccp4/p3d/seg45 rg3 st cmos general purpose i/o. an13 an ? a/d channel 13 input. cps13 an ? capacitive sensing input 13. c3in0- an ? comparator c3 negative input. ccp4 st cmos capture/compare/pwm4. p3d ? cmos pwm output. seg45 ? an lcd analog output. rg4/an12/cps12/c3in1-/ ccp5/p1d/seg26 rg4 st cmos general purpose i/o. an12 an ? a/d channel 12 input. cps12 an ? capacitive sensing input 12. c3in1- an ? comparator c3 negative input. ccp5 st cmos capture/compare/pwm5. p1d ? cmos pwm output. seg26 ? an lcd analog output. rg5/mclr /v pp rg5 ttl ? general purpose input. mclr st ? master clear with internal pull-up. v pp hv ? programming voltage. v dd v dd power ? positive supply. v ss v ss power ? ground reference. table 1-2: pic16(l)f1946/1947 pinout description (continued) name function input type output type description legend: an = analog input or output cmos = cmos compatible input or output od = open drain ttl = ttl compatible input st = schmitt trigger input with cmos levels i 2 c? = schmitt trigger input with i 2 c hv = high voltage xtal = crystal levels note 1: pin function is selectable via the apfcon register.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 19 pic16(l)f1946/1947 2.0 enhanced mid-range cpu this family of devices contain an enhanced mid-range 8-bit cpu core. the cpu has 49 instructions. interrupt capability includes automatic context saving. the hardware stack is 16 levels deep and has overflow and underflow reset capability. direct, indirect, and relative addressing modes are available. two file select registers (fsrs) provide the ability to read program and data memory. ? automatic interrupt context saving ? 16-level stack with overflow and underflow ? file select registers ? instruction set 2.1 automatic interrupt context saving during interrupts, certain registers are automatically saved in shadow registers and restored when returning from the interrupt. this saves stack space and user code. see section 7.5 ?automatic context saving? , for more information. 2.2 16-level stack with overflow and underflow these devices have an external stack memory 15 bits wide and 16 words deep. a stack overflow or under- flow will set the appropriate bit (stkovf or stkunf) in the pcon register, and if enabled will cause a soft- ware reset. see section section 3.4 ?stack? for more details. 2.3 file select registers there are two 16-bit file select registers (fsr). fsrs can access all file registers and program memory, which allows one data pointer for all memory. when an fsr points to program memory, there is 1 additional instruction cycle in instructions using indf to allow the data to be fetched. general purpose memory can now also be addressed linearly, providing the ability to access contiguous data larger than 80 bytes. there are also new instructions to support the fsrs. see section 3.5 ?indirect addressing? for more details. 2.4 instruction set there are 49 instructions for the enhanced mid-range cpu to support the features of the cpu. see section 29.0 ?instruction set summary? for more details.
pic16(l)f1946/1947 ds41414c-page 20 preliminary ? 2010-2011 microchip technology inc. figure 2-1: core block diagram data bus 8 14 program bus instruction reg program counter 8 level stack (13-bit) direct addr 7 12 addr mux fsr reg status reg mux alu power-up timer oscillator start-up timer power-on reset watchdog timer instruction decode & control timing generation osc1/clkin osc2/clkout v dd 8 8 brown-out reset 12 3 v ss internal oscillator block configuration data bus 8 14 program bus instruction reg program counter 8 level stack (13-bit) direct addr 7 addr mux fsr reg status reg mux alu w reg instruction decode & control timing generation v dd 8 8 3 v ss internal oscillator block configuration 15 data bus 8 14 program bus instruction reg program counter 16-level stack (15-bit) direct addr 7 ram addr addr mux indirect addr fsr0 reg status reg mux alu instruction decode and control timing generation v dd 8 8 3 v ss internal oscillator block configuration flash program memory ram fsr reg fsr reg fsr1 reg 15 15 mux 15 program memory read (pmr) 12 fsr reg fsr reg bsr reg 5
? 2010-2011 microchip technology inc. preliminary ds41414c-page 21 pic16(l)f1946/1947 3.0 memory organization there are three types of memory in pic16f/lf1946/47 devices: data memory, program memory and data eeprom memory (1) . ? program memory ? data memory - core registers - special function registers - general purpose ram - common ram - device memory maps - special function registers summary ? data eeprom memory (1) the following features are associated with access and control of program memory and data memory: ? pcl and pclath ?stack ? indirect addressing 3.1 program memory organization the enhanced mid-range core has a 15-bit program counter capable of addr essing 32k x 14 program memory space. table 3-1 shows the memory sizes implemented for the pic16f/lf1946/47 family. accessing a location above these boundaries will cause a wrap-around within the implemented memory space. the reset vector is at 0000h and the interrupt vector is at 0004h (see figures 3-1 and 3-2 ). note 1: the data eeprom memory and the method to access flash memory through the eecon registers is described in section 11.0 ?data eeprom and flash program memory control? . table 3-1: device sizes and addresses device program memory space (words) last program memory address pic16f/lf1946 8,192 1fffh pic16f/lf1947 16,384 3fffh
pic16(l)f1946/1947 ds41414c-page 22 preliminary ? 2010-2011 microchip technology inc. figure 3-1: program memory map and stack for pic16f/lf1946 figure 3-2: program memory map and stack for pic16f/lf1947 pc<14:0> 15 0000h 0004h stack level 0 stack level 15 reset vector interrupt vector stack level 1 0005h on-chip program memory page 0 07ffh rollover to page 0 0800h 0fffh 1000h 7fffh page 1 rollover to page 3 page 2 page 3 17ffh 1800h 1fffh 2000h call, callw return, retlw interrupt , retfie pc<14:0> 15 0000h 0004h stack level 0 stack level 15 reset vector interrupt vector stack level 1 0005h on-chip program memory page 0 07ffh rollover to page 0 0800h 0fffh 1000h 7fffh page 1 rollover to page 7 page 2 page 3 17ffh 1800h 1fffh 2000h page 4 page 7 3fffh 4000h call, callw return, retlw interrupt , retfie
? 2010-2011 microchip technology inc. preliminary ds41414c-page 23 pic16(l)f1946/1947 3.1.1 reading program memory as data there are two methods of accessing constants in pro- gram memory. the first method is to use tables of retlw instructions. the second method is to set an fsr to point to the program memory. 3.1.1.1 retlw instruction the retlw instruction can be used to provide access to tables of constants. the recommended way to create such a table is shown in example 3-1 . example 3-1: retlw instruction the brw instruction makes this type of table very simple to implement. if your code must remain portable with previous generations of microcontrollers, then the brw instruction is not available so the older table read method must be used. constants brw ;add index in w to ;program counter to ;select data retlw data0 ;index0 data retlw data1 ;index1 data retlw data2 retlw data3 my_function ;? lots of code? movlw data_index call constants ;? the constant is in w
pic16(l)f1946/1947 ds41414c-page 24 preliminary ? 2010-2011 microchip technology inc. 3.1.1.2 indirect read with fsr the program memory can be accessed as data by set- ting bit 7 of the fsrxh register and reading the match- ing indfx register. the moviw instruction will place the lower 8 bits of the addressed word in the w register. writes to the program memory cannot be performed via the indf registers. instructions that access the pro- gram memory via the fsr require one extra instruction cycle to complete. example 3-2 demonstrates access- ing the program memory via an fsr. the high directive will set bit<7> if a label points to a location in program memory. example 3-2: accessing program memory via fsr 3.2 data memory organization the data memory is partitioned in 32 memory banks with 128 bytes in a bank. each bank consists of ( figure 3-3 ): ? 12 core registers ? 20 special function registers (sfr) ? up to 80 bytes of general purpose ram (gpr) ? 16 bytes of common ram the active bank is selected by writing the bank number into the bank select register (bsr). unimplemented memory will read as ? 0 ?. all data memory can be accessed either directly (via instructions that use the file registers) or indirectly via the two file select registers (fsr). see section 3.5 ?indirect addressing? for more information. 3.2.1 core registers the core registers contain the registers that directly affect the basic operation of the pic16f/lf1946/47. these registers are listed below: ? indf0 ? indf1 ?pcl ?status ?fsr0 low ? fsr0 high ?fsr1 low ? fsr1 high ? bsr ?wreg ?pclath ? intcon constants retlw data0 ;index0 data retlw data1 ;index1 data retlw data2 retlw data3 my_function ;? lots of code? movlw low constants movwf fsr1l movlw high constants movwf fsr1h moviw 0[fsr1] ;the program memory is in w note: the core registers are the first 12 addresses of every data memory bank.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 25 pic16(l)f1946/1947 3.2.1.1 status register the status register, shown in register 3-1 , contains: ? the arithmetic status of the alu ? the reset status the status register can be the destination for any instruction, like any other register. if the status register is the destination for an instruction that affects the z, dc or c bits, then the write to these three bits is disabled. these bits are set or cleared according to the device logic. furthermore, the to and pd bits are not writable. therefore, the result of an instruction with the status register as destination may be different than intended. for example, clrf status will clear the upper three bits and set the z bit. this leaves the status register as ? 000u u1uu ? (where u = unchanged). it is recommended, therefore, that only bcf, bsf, swapf and movwf instructions are used to alter the status register, because these instructions do not affect any status bits. for other instructions not affecting any status bits (refer to section 29.0 ?instruction set summary? ). note 1: the c and dc bits operate as borrow and digit borrow out bits, respectively, in subtraction. register 3-1: status: status register u-0 u-0 u-0 r-1/q r-1/q r/w-0/u r/w-0/u r/w-0/u ? ? ? to pd zdc (1) c (1) bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared q = value depends on condition bit 7-5 unimplemented: read as ? 0 ? bit 4 to : time-out bit 1 = after power-up, clrwdt instruction or sleep instruction 0 = a wdt time-out occurred bit 3 pd : power-down bit 1 = after power-up or by the clrwdt instruction 0 = by execution of the sleep instruction 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/digit borrow bit ( addwf , addlw,sublw,subwf instructions) (1) 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 (1) ( addwf , addlw, sublw, subwf instructions) (1) 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 executed by adding the two?s complement of the second operand. for rotate ( rrf , rlf ) instructions, this bit is loaded with either the high-order or low-order bit of the source register.
pic16(l)f1946/1947 ds41414c-page 26 preliminary ? 2010-2011 microchip technology inc. 3.2.2 special function register the special function registers are registers used by the application to control the desired operation of peripheral functions in the device. the registers asso- ciated with the operation of the peripherals are described in the appropriate peripheral chapter of this data sheet. 3.2.3 general purpose ram there are up to 80 bytes of gpr in each data memory bank. 3.2.3.1 linear access to gpr the general purpose ram can be accessed in a non-banked method via the fsrs. this can simplify access to large memory structures. see section 3.5.2 ?linear data memory? for more information. 3.2.4 common ram there are 16 bytes of common ram accessible from all banks. figure 3-3: banked memory partitioning 3.2.5 device memory maps the memory maps for the device family are as shown in table 3-2 . 0bh 0ch 1fh 20h 6fh 70h 7fh 00h common ram (16 bytes) general purpose ram (80 bytes maximum) core registers (12 bytes) special function registers (20 bytes maximum) memory region 7-bit bank offset table 3-2: memory map tables device banks table no. pic16f/lf1946/47 0-7 table 3-3 8-15 table 3-4 , table 3-7 16-23 table 3-5 23-31 table 3-6 , table 3-8
pic16(l)f1946/1947 ds41414c-page 27 preliminary ? 2010-2011 microchip technology inc. table 3-3: pic16f/lf1946/1947 memory map, banks 0-7 legend: = unimplemented data memory locations, read as ? 0 ?. note 1: not available on pic16f1946. bank 0 bank 1 bank 2 bank 3 bank 4 bank 5 bank 6 bank 7 000h indf0 080h indf0 100h indf0 180h indf0 200h indf0 280h indf0 300h indf0 380h indf0 001h indf1 081h indf1 101h indf1 181h indf1 201h indf1 281h indf1 301h indf1 381h indf1 002h pcl 082h pcl 102h pcl 182h pcl 202h pcl 282h pcl 302h pcl 382h pcl 003h status 083h status 103h status 183h status 203h status 283h status 303h status 383h status 004h fsr0l 084h fsr0l 104h fsr0l 184h fsr0l 204h fsr0l 284h fsr0l 304h fsr0l 384h fsr0l 005h fsr0h 085h fsr0h 105h fsr0h 185h fsr0h 205h fsr0h 285h fsr0h 305h fsr0h 385h fsr0h 006h fsr1l 086h fsr1l 106h fsr1l 186h fsr1l 206h fsr1l 286h fsr1l 306h fsr1l 386h fsr1l 007h fsr1h 087h fsr1h 107h fsr1h 187h fsr1h 207h fsr1h 287h fsr1h 307h fsr1h 387h fsr1h 008h bsr 088h bsr 108h bsr 188h bsr 208h bsr 288h bsr 308h bsr 388h bsr 009h wreg 089h wreg 109h wreg 189h wreg 209h wreg 289h wreg 309h wreg 389h wreg 00ah pclath 08ah pclath 10ah pclath 18ah pclath 20ah pclath 28ah pclath 30ah pclath 38ah pclath 00bh intcon 08bh intcon 10bh intcon 18bh intcon 20bh intcon 28bh intcon 30bh intcon 38bh intcon 00ch porta 08ch trisa 10ch lata 18ch ansela 20ch ? 28ch portf 30ch trisf 38ch latf 00dh portb 08dh trisb 10dh latb 18dh ? 20dh wpub 28dh portg 30dh trisg 38dh latg 00eh portc 08eh trisc 10eh latc 18eh ?20eh ?28eh ?30eh ?38eh ? 00fh portd 08fh trisd 10fh latd 18fh ?20fh ?28fh ?30fh ?38fh ? 010h porte 090h trise 110h late 190h ansele 210h ?290h ? 310h ? 390h ? 011h pir1 091h pie1 111h cm1con0 191h eeadrl 211h ssp1buf 291h ccpr1l 311h ccpr3l 391h ? 012h pir2 092h pie2 112h cm1con1 192h eeadrh 212h ssp1add 292h ccpr1h 312h ccpr3h 392h ? 013h pir3 093h pie3 113h cm2con0 193h eedatl 213h ssp1msk 293h ccp1con 313h ccp3con 393h ? 014h pir4 094h pie4 114h cm2con1 194h eedath 214h ssp1stat 294h pwm1con 314h pwm3con 394h iocbp 015h tmr0 095h option 115h cmout 195h eecon1 215h ssp1con1 295h ccp1as 315h ccp3as 395h iocbn 016h tmr1l 096h pcon 116h borcon 196h eecon2 216h ssp1con2 296h pstr1con 316h pstr3con 396h iocbf 017h tmr1h 097h wdtcon 117h fvrcon 197h ? 217h ssp1con3 297h ? 317h ? 397h ? 018h t1con 098h osctune 118h daccon0 198h ?218h ? 298h ccpr2l 318h ccpr4l 398h ? 019h t1gcon 099h osccon 119h daccon1 199h rc1reg 219h ssp2buf 299h ccpr2h 319h ccpr4h 399h ? 01ah tmr2 09ah oscstat 11ah srcon0 19ah tx1reg 21ah ssp2add 29ah ccp2con 31ah ccp4con 39ah ? 01bh pr2 09bh adresl 11bh srcon1 19bh sp1brgl 21bh ssp2msk 29bh pwm2con 31bh ?39bh ? 01ch t2con 09ch adresh 11ch ? 19ch sp1brgh 21ch ssp2stat 29ch ccp2as 31ch ccpr5l 39ch ? 01dh ? 09dh adcon0 11dh apfcon 19dh rc1sta 21dh ssp2con1 29dh pstr2con 31dh ccpr5h 39dh ? 01eh cpscon0 09eh adcon1 11eh cm3con0 19eh tx1sta 21eh ssp2con2 29eh ccptmrs0 31eh ccp5con 39eh ? 01fh cpscon1 09fh ? 11fh cm3con1 19fh baud1con 21fh ssp2con3 29fh ccptmrs1 31fh ?39fh ? 020h general purpose register 96 bytes 0a0h general purpose register 80 bytes 120h general purpose register 80 bytes 1a0h general purpose register 80 bytes 220h general purpose register 80 bytes 2a0h general purpose register 80 bytes 320h general purpose register 16 bytes 3a0h general purpose register 80 bytes (1) 32fh 330h general purpose register 64 bytes (1) 06fh 0efh 16fh 1efh 26fh 2efh 36fh 3efh 070h 0f0h accesses 70h ? 7fh 170h accesses 70h ? 7fh 1f0h accesses 70h ? 7fh 270h accesses 70h ? 7fh 2f0h accesses 70h ? 7fh 370h accesses 70h ? 7fh 3f0h accesses 70h ? 7fh 07fh 0ffh 17fh 1ffh 27fh 2ffh 37fh 3ffh
pic16(l)f1946/1947 ds41414c-page 28 preliminary ? 2010-2011 microchip technology inc. table 3-4: pic16f/lf1946/1947 memory map, banks 8-15 legend: = unimplemented data memory locations, read as ? 0 ? note 1: not available on pic16f1946. bank 8 bank 9 bank 10 bank 11 bank 12 bank 13 bank 14 bank 15 400h indf0 480h indf0 500h indf0 580h indf0 600h indf0 680h indf0 700h indf0 780h indf0 401h indf1 481h indf1 501h indf1 581h indf1 601h indf1 681h indf1 701h indf1 781h indf1 402h pcl 482h pcl 502h pcl 582h pcl 602h pcl 682h pcl 702h pcl 782h pcl 403h status 483h status 503h status 583h status 603h status 683h status 703h status 783h status 404h fsr0l 484h fsr0l 504h fsr0l 584h fsr0l 604h fsr0l 684h fsr0l 704h fsr0l 784h fsr0l 405h fsr0h 485h fsr0h 505h fsr0h 585h fsr0h 605h fsr0h 685h fsr0h 705h fsr0h 785h fsr0h 406h fsr1l 486h fsr1l 506h fsr1l 586h fsr1l 606h fsr1l 686h fsr1l 706h fsr1l 786h fsr1l 407h fsr1h 487h fsr1h 507h fsr1h 587h fsr1h 607h fsr1h 687h fsr1h 707h fsr1h 787h fsr1h 408h bsr 488h bsr 508h bsr 588h bsr 608h bsr 688h bsr 708h bsr 788h bsr 409h wreg 489h wreg 509h wreg 589h wreg 609h wreg 689h wreg 709h wreg 789h wreg 40ah pclath 48ah pclath 50ah pclath 58ah pclath 60ah pclath 68ah pclath 70ah pclath 78ah pclath 40bh intcon 48bh intcon 50bh intcon 58bh intcon 60bh intcon 68bh intcon 70bh intcon 78bh intcon 40ch anself 48ch ? 50ch ? 58ch ? 60ch ? 68ch ? 70ch ? 78ch ? 40dh anselg 48dh wpug 50dh ? 58dh ? 60dh ? 68dh ? 70dh ? 78dh ? 40eh ? 48eh ? 50eh ? 58eh ? 60eh ? 68eh ? 70eh ? 78eh ? 40fh ? 48fh ? 50fh ? 58fh ? 60fh ? 68fh ? 70fh ? 78fh ? 410h ? 490h ? 510h ? 590h ? 610h ? 690h ? 710h ? 790h ? 411h ? 491h rc2reg 511h ? 591h ? 611h ? 691h ? 711h ? 791h see ta b l e 3 - 7 412h ? 492h tx2reg 512h ? 592h ? 612h ? 692h ? 712h ? 792h 413h ? 493h sp2brg 513h ? 593h ? 613h ? 693h ? 713h ? 793h 414h ? 494h sp2brgh 514h ? 594h ? 614h ? 694h ? 714h ? 794h 415h tmr4 495h rc2sta 515h ? 595h ? 615h ? 695h ? 715h ? 795h 416h pr4 496h tx2sta 516h ? 596h ? 616h ? 696h ? 716h ? 796h 417h t4con 497h baudcon2 517h ? 597h ? 617h ? 697h ? 717h ? 797h 418h ? 498h ? 518h ? 598h ? 618h ? 698h ? 718h ? 798h 419h ? 499h ? 519h ? 599h ? 619h ? 699h ? 719h ? 799h 41ah ? 49ah ? 51ah ? 59ah ? 61ah ? 69ah ? 71ah ? 79ah 41bh ? 49bh ? 51bh ? 59bh ? 61bh ? 69bh ? 71bh ? 79bh 41ch tmr6 49ch ? 51ch ? 59ch ? 61ch ? 69ch ? 71ch ? 79ch 41dh pr6 49dh ? 51dh ? 59dh ? 61dh ? 69dh ? 71dh ? 79dh 41eh t6con 49eh ? 51eh ? 59eh ? 61eh ? 69eh ? 71eh ? 79eh 41fh ? 49fh ? 51fh ? 59fh ? 61fh ? 69fh ? 71fh ? 79fh 420h general purpose register 80 bytes (1) 4a0h general purpose register 80 bytes (1) 520h general purpose register 80 bytes (1) 5a0h general purpose register 80 bytes (1) 620h general purpose register 48 bytes (1) 6a0h unimplemented read as ? 0 ? 720h unimplemented read as ? 0 ? 7a0h unimplemented read as ? 0 ? 46fh 4efh 56fh 5efh 66fh 6efh 76fh 7efh 470h accesses 70h ? 7fh 4f0h accesses 70h ? 7fh 570h accesses 70h ? 7fh 5f0h accesses 70h ? 7fh 670h accesses 70h ? 7fh 6f0h accesses 70h ? 7fh 770h accesses 70h ? 7fh 7f0h accesses 70h ? 7fh 47fh 4ffh 57fh 5ffh 67fh 6ffh 77fh 7ffh
pic16(l)f1946/1947 ds41414c-page 29 preliminary ? 2010-2011 microchip technology inc. table 3-5: pic16f/lf1946/47 memory map, banks 16-23 legend: = unimplemented data memory locations, read as ? 0 ?. bank 16 bank 17 bank 18 bank 19 bank 20 bank 21 bank 22 bank 23 800h indf0 880h indf0 900h indf0 980h indf0 a00h indf0 a80h indf0 b00h indf0 b80h indf0 801h indf1 881h indf1 901h indf1 981h indf1 a01h indf1 a81h indf1 b01h indf1 b81h indf1 802h pcl 882h pcl 902h pcl 982h pcl a02h pcl a82h pcl b02h pcl b82h pcl 803h status 883h status 903h status 983h status a03h status a83h status b03h status b83h status 804h fsr0l 884h fsr0l 904h fsr0l 984h fsr0l a04h fsr0l a84h fsr0l b04h fsr0l b84h fsr0l 805h fsr0h 885h fsr0h 905h fsr0h 985h fsr0h a05h fsr0h a85h fsr0h b05h fsr0h b85h fsr0h 806h fsr1l 886h fsr1l 906h fsr1l 986h fsr1l a06h fsr1l a86h fsr1l b06h fsr1l b86h fsr1l 807h fsr1h 887h fsr1h 907h fsr1h 987h fsr1h a07h fsr1h a87h fsr1h b07h fsr1h b87h fsr1h 808h bsr 888h bsr 908h bsr 988h bsr a08h bsr a88h bsr b08h bsr b88h bsr 809h wreg 889h wreg 909h wreg 989h wreg a09h wreg a89h wreg b09h wreg b89h wreg 80ah pclath 88ah pclath 90ah pclath 98ah pclath a0ah pclath a8ah pclath b0ah pclath b8ah pclath 80bh intcon 88bh intcon 90bh intcon 98bh intcon a0bh intcon a8bh intcon b0bh intcon b8bh intcon 80ch ? 88ch ? 90ch ? 98ch ?a0ch ?a8ch ?b0ch ?b8ch ? 80dh ? 88dh ? 90dh ? 98dh ?a0dh ?a8dh ?b0dh ?b8dh ? 80eh ?88eh ?90eh ?98eh ?a0eh ?a8eh ?b0eh ?b8eh ? 80fh ?88fh ?90fh ?98fh ?a0fh ?a8fh ?b0fh ?b8fh ? 810h ?890h ?910h ?990h ?a10h ?a90h ?b10h ?b90h ? 811h ?891h ?911h ?991h ?a11h ?a91h ?b11h ?b91h ? 812h ?892h ?912h ?992h ?a12h ?a92h ?b12h ?b92h ? 813h ?893h ?913h ?993h ?a13h ?a93h ?b13h ?b93h ? 814h ?894h ?914h ?994h ?a14h ?a94h ?b14h ?b94h ? 815h ?895h ?915h ?995h ?a15h ?a95h ?b15h ?b95h ? 816h ?896h ?916h ?996h ?a16h ?a96h ?b16h ?b96h ? 817h ?897h ?917h ?997h ?a17h ?a97h ?b17h ?b97h ? 818h ?898h ?918h ?998h ?a18h ?a98h ?b18h ?b98h ? 819h ?899h ?919h ?999h ?a19h ?a99h ?b19h ?b99h ? 81ah ?89ah ?91ah ?99ah ?a1ah ?a9ah ?b1ah ?b9ah ? 81bh ?89bh ?91bh ?99bh ?a1bh ?a9bh ?b1bh ?b9bh ? 81ch ? 89ch ? 91ch ? 99ch ?a1ch ?a9ch ?b1ch ?b9ch ? 81dh ? 89dh ? 91dh ? 99dh ?a1dh ?a9dh ?b1dh ?b9dh ? 81eh ?89eh ?91eh ?99eh ?a1eh ?a9eh ?b1eh ?b9eh ? 81fh ?89fh ?91fh ?99fh ?a1fh ?a9fh ?b1fh ?b9fh ? 820h unimplemented read as ? 0 ? 8a0h unimplemented read as ? 0 ? 920h unimplemented read as ? 0 ? 9a0h unimplemented read as ? 0 ? a20h unimplemented read as ? 0 ? aa0h unimplemented read as ? 0 ? b20h unimplemented read as ? 0 ? ba0h unimplemented read as ? 0 ? 86fh 8efh 96fh 9efh a6fh aefh b6fh befh 870h accesses 70h ? 7fh 8f0h accesses 70h ? 7fh 970h accesses 70h ? 7fh 9f0h accesses 70h ? 7fh a70h accesses 70h ? 7fh af0h accesses 70h ? 7fh b70h accesses 70h ? 7fh bf0h accesses 70h ? 7fh 87fh 8ffh 97fh 9ffh a7fh affh b7fh bffh
pic16(l)f1946/1947 ds41414c-page 30 preliminary ? 2010-2011 microchip technology inc. table 3-6: pic16f/lf1946/47 memory map, banks 24-31 legend: = unimplemented data memory locations, read as ? 0 ?. bank 24 bank 25 bank 26 bank 27 bank 28 bank 29 bank 30 bank 31 c00h indf0 c80h indf0 d00h indf0 d80h indf0 e00h indf0 e80h indf0 f00h indf0 f80h indf0 c01h indf1 c81h indf1 d01h indf1 d81h indf1 e01h indf1 e81h indf1 f01h indf1 f81h indf1 c02h pcl c82h pcl d02h pcl d82h pcl e02h pcl e82h pcl f02h pcl f82h pcl c03h status c83h status d03h status d83h status e03h status e83h status f03h status f83h status c04h fsr0l c84h fsr0l d04h fsr0l d84h fsr0l e04h fsr0l e84h fsr0l f04h fsr0l f84h fsr0l c05h fsr0h c85h fsr0h d05h fsr0h d85h fsr0h e05h fsr0h e85h fsr0h f05h fsr0h f85h fsr0h c06h fsr1l c86h fsr1l d06h fsr1l d86h fsr1l e06h fsr1l e86h fsr1l f06h fsr1l f86h fsr1l c07h fsr1h c87h fsr1h d07h fsr1h d87h fsr1h e07h fsr1h e87h fsr1h f07h fsr1h f87h fsr1h c08h bsr c88h bsr d08h bsr d88h bsr e08h bsr e88h bsr f08h bsr f88h bsr c09h wreg c89h wreg d09h wreg d89h wreg e09h wreg e89h wreg f09h wreg f89h wreg c0ah pclath c8ah pclath d0ah pclath d8ah pclath e0ah pclath e8ah pclath f0ah pclath f8ah pclath c0bh intcon c8bh intcon d0bh intcon d8bh intcon e0bh intcon e8bh intcon f0bh intcon f8bh intcon c0ch ?c8ch ?d0ch ?d8ch ?e0ch ?e8ch ?f0ch ?f8ch see ta b l e 3 - 8 c0dh ?c8dh ?d0dh ?d8dh ?e0dh ?e8dh ?f0dh ?f8dh c0eh ?c8eh ?d0eh ?d8eh ?e0eh ?e8eh ?f0eh ?f8eh c0fh ?c8fh ?d0fh ?d8fh ?e0fh ?e8fh ?f0fh ?f8fh c10h ?c90h ?d10h ?d90h ?e10h ?e90h ?f10h ?f90h c11h ?c91h ?d11h ?d91h ?e11h ?e91h ?f11h ?f91h c12h ?c92h ?d12h ?d92h ?e12h ?e92h ?f12h ?f92h c13h ?c93h ?d13h ?d93h ?e13h ?e93h ?f13h ?f93h c14h ?c94h ?d14h ?d94h ?e14h ?e94h ?f14h ?f94h c15h ?c95h ?d15h ?d95h ?e15h ?e95h ?f15h ?f95h c16h ?c96h ?d16h ?d96h ?e16h ?e96h ?f16h ?f96h c17h ?c97h ?d17h ?d97h ?e17h ?e97h ?f17h ?f97h c18h ?c98h ?d18h ?d98h ?e18h ?e98h ?f18h ?f98h c19h ?c99h ?d19h ?d99h ?e19h ?e99h ?f19h ?f99h c1ah ?c9ah ?d1ah ?d9ah ?e1ah ?e9ah ?f1ah ?f9ah c1bh ?c9bh ?d1bh ?d9bh ?e1bh ?e9bh ?f1bh ?f9bh c1ch ?c9ch ?d1ch ?d9ch ?e1ch ?e9ch ?f1ch ?f9ch c1dh ?c9dh ?d1dh ?d9dh ?e1dh ?e9dh ?f1dh ?f9dh c1eh ?c9eh ?d1eh ?d9eh ?e1eh ?e9eh ?f1eh ?f9eh c1fh ?c9fh ?d1fh ?d9fh ?e1fh ?e9fh ?f1fh ?f9fh c20h unimplemented read as ? 0 ? ca0h unimplemented read as ? 0 ? d20h unimplemented read as ? 0 ? da0h unimplemented read as ? 0 ? e20h unimplemented read as ? 0 ? ea0h unimplemented read as ? 0 ? f20h unimplemented read as ? 0 ? fa0h c6fh cefh d6fh defh e6fh eefh f6fh fefh c70h accesses 70h ? 7fh cf0h accesses 70h ? 7fh d70h accesses 70h ? 7fh df0h accesses 70h ? 7fh e70h accesses 70h ? 7fh ef0h accesses 70h ? 7fh f70h accesses 70h ? 7fh ff0h accesses 70h ? 7fh cffh cffh d7fh dffh e7fh effh f7fh fffh
? 2010-2011 microchip technology inc. preliminary ds41414c-page 31 pic16(l)f1946/1947 table 3-7: pic16f/lf1946/47 memory map, bank 15 table 3-8: pic16f/lf1946/47 memory map, bank 31 legend: = unimplemented data memory locations, read as ? 0 ?. bank 15 791h lcdcon 792h lcdps 793h lcdref 794h lcdcst 795h lcdrl 796h ? 797h ? 798h lcdse0 799h lcdse1 79ah lcdse2 79bh lcdse3 79ch lcdse4 79dh lcdse5 79eh ? 79fh ? 7a0h lcddata0 7a1h lcddata1 7a2h lcddata2 7a3h lcddata3 7a4h lcddata4 7a5h lcddata5 7a6h lcddata6 7a7h lcddata7 7a8h lcddata8 7a9h lcddata9 7aah lcddata10 7abh lcddata11 7ach lcddata12 7adh lcddata13 7aeh lcddata14 7afh lcddata15 7b0h lcddata16 7b1h lcddata17 7b2h lcddata18 7b3h lcddata19 7b4h lcddata20 7b5h lcddata21 7b6h lcddata22 7b7h lcddata23 7b8h unimplemented read as ? 0 ? 7efh legend: = unimplemented data memory locations, read as ? 0 ?. bank 31 f8ch ? f8dh ? f8eh ? f8fh ? f90h ? f91h ? f92h ? f93h ? f94h ? f95h ? f96h ? f97h ? f98h ? f99h ? f9ah ? f9bh ? f9ch ? f9dh ? f9eh ? f9fh ? fa0h ? fa1h ? fa2h ? fa3h ? fa4h ? fa5h ? fa6h ? fa7h ? fa8h ? fa9h ? faah ? fabh ? fdfh ? fc0h ? fdfh ? fe0h ? fe1h ? fe2h ? fe3h ? fe4h status_shad fe5h wreg_shad fe6h bsr_shad fe7h pclath_shad fe8h fsr0l_shad fe9h fsr0h_shad feah fsr1l_shad febh fsr1h_shad fech ? fedh stkptr feeh tosl fefh tosh
pic16(l)f1946/1947 ds41414c-page 32 preliminary ? 2010-2011 microchip technology inc. 3.2.6 special function registers summary the special function register summary for the device family are as follows: device bank(s) page no. pic16(l)f1946/1947 033 134 235 336 437 538 639 740 841 9-14 43 15 44 16-30 46 31 47
? 2010-2011 microchip technology inc. preliminary ds41414c-page 33 pic16(l)f1946/1947 table 3-9: special function register summary address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets bank 0 000h (2) indf0 addressing this location uses contents of fsr0h/fsr0l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 001h (2) indf1 addressing this location uses contents of fsr1h/fsr1l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 002h (2) pcl program counter (pc) least significant byte 0000 0000 0000 0000 003h (2) status ? ? ?to pd zdcc ---1 1000 ---q quuu 004h (2) fsr0l indirect data memory address 0 low pointer 0000 0000 uuuu uuuu 005h (2) fsr0h indirect data memory address 0 high pointer 0000 0000 0000 0000 006h (2) fsr1l indirect data memory address 1 low pointer 0000 0000 uuuu uuuu 007h (2) fsr1h indirect data memory address 1 high pointer 0000 0000 0000 0000 008h (2) bsr ? ? ? bsr<4:0> ---0 0000 ---0 0000 009h (2) wreg working register 0000 0000 uuuu uuuu 00ah (1, 2) pclath ? write buffer for the upper 7 bits of the program counter -000 0000 -000 0000 00bh (2) intcon gie peie tmr0ie inte iocie tmr0if intf iocif 0000 000x 0000 000u 00ch porta porta data latch when written: porta pins when read xxxx xxxx uuuu uuuu 00dh portb portb data latch when written: portb pins when read xxxx xxxx uuuu uuuu 00eh portc portc data latch when written: portc pins when read xxxx xxxx uuuu uuuu 00fh portd portd data latch when written: portd pins when read xxxx xxxx uuuu uuuu 010h porte porte data latch when written: porte pins when read xxxx xxxx xxxx uuuu 011h pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 0000 0000 0000 0000 012h pir2 osfif c2if c1if eeif bclif lcdif c3if ccp2if 0000 0000 0000 0000 013h pir3 ? ccp5if ccp4if ccp3if tmr6if ?tmr4if ? -000 0-0- -000 0-0- 014h pir4 ? ? rc2if tx2if ? ? bcl2if ssp2if --00 --00 --00 --00 015h tmr0 timer0 module register xxxx xxxx uuuu uuuu 016h tmr1l holding register for the least significant byte of the 16-bit tmr1 register xxxx xxxx uuuu uuuu 017h tmr1h holding register for the most significant byte of the 16-bit tmr1 register xxxx xxxx uuuu uuuu 018h t1con tmr1cs<1:0> t1ckps<1:0> t1oscen t1sync ?tmr1on 0000 00-0 uuuu uu-u 019h t1gcon tmr1ge t1gpol t1gtm t1gspm t1ggo/ done t1gval t1gss<1:0> 0000 0x00 uuuu uxuu 01ah tmr2 timer 2 module register 0000 0000 0000 0000 01bh pr2 timer 2 period register 1111 1111 1111 1111 01ch t2con ? t2outps<3:0> tmr2on t2ckps<1:0> -000 0000 -000 0000 01dh ? unimplemented ? ? 01eh cpscon0 cpson cpsrm ? ? cpsrng1 cpsrng0 cpsout t0xcs 00-- 0000 00-- 0000 01fh cpscon1 ? ? ? cpsch<4:0> ---0 0000 ---0 0000 legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
pic16(l)f1946/1947 ds41414c-page 34 preliminary ? 2010-2011 microchip technology inc. bank 1 080h (2) indf0 addressing this location uses contents of fsr0h/fsr0l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 081h (2) indf1 addressing this location uses contents of fsr1h/fsr1l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 082h (2) pcl program counter (pc) least significant byte 0000 0000 0000 0000 083h (2) status ? ? ?to pd zdcc ---1 1000 ---q quuu 084h (2) fsr0l indirect data memory address 0 low pointer 0000 0000 uuuu uuuu 085h (2) fsr0h indirect data memory address 0 high pointer 0000 0000 0000 0000 086h (2) fsr1l indirect data memory address 1 low pointer 0000 0000 uuuu uuuu 087h (2) fsr1h indirect data memory address 1 high pointer 0000 0000 0000 0000 088h (2) bsr ? ? ? bsr<4:0> ---0 0000 ---0 0000 089h (2) wreg working register 0000 0000 uuuu uuuu 08ah (1, 2) pclath ? write buffer for the upper 7 bits of the program counter -000 0000 -000 0000 08bh (2) intcon gie peie tmr0ie inte iocie tmr0if intf iocif 0000 000x 0000 000u 08ch trisa porta data direction register 1111 1111 1111 1111 08dh trisb portb data direction register 1111 1111 1111 1111 08eh trisc portc data direction register 1111 1111 1111 1111 08fh trisd portd data direction register 1111 1111 1111 1111 090h trise porte data direction register 1111 1111 1111 1111 091h pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 0000 0000 0000 0000 092h pie2 osfie c2ie c1ie eeie bclie lcdie c3ie ccp2ie 0000 0000 0000 0000 093h pie3 ? ccp5ie ccp4ie ccp3ie tmr6ie ?tmr4ie ? -000 0-0- -000 0-0- 094h pie4 ? ? rc2ie tx2ie ? ? bcl2ie ssp2ie --00 --00 --00 --00 095h option_reg wpuen intedg t0cs t0se psa ps<2:0> 1111 1111 1111 1111 096h pcon stkovf stkunf ? ?rmclr ri por bor 00-- 11qq qq-- qquu 097h wdtcon ? ? wdtps<4:0> swdten --01 0110 --01 0110 098h osctune ? ?tun<5:0> --00 0000 --00 0000 099h osccon spllen ircf<3:0> ?scs<1:0> 0011 1-00 0011 1-00 09ah oscstat t1oscr pllr osts hfiofr hfiofl mfiofr lfiofr hfiofs 00q0 0q0- qqqq qq0- 09bh adresl a/d result register low xxxx xxxx uuuu uuuu 09ch adresh a/d result register high xxxx xxxx uuuu uuuu 09dh adcon0 ? chs<4:0> go/done adon -000 0000 -000 0000 09eh adcon1 adfm adcs<2:0> ? adnref adpref1 adpref0 0000 -000 0000 -000 09fh ? unimplemented ? ? table 3-9: special function register summary (continued) address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 35 pic16(l)f1946/1947 bank 2 100h (2) indf0 addressing this location uses contents of fsr0h/fsr0l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 101h (2) indf1 addressing this location uses contents of fsr1h/fsr1l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 102h (2) pcl program counter (pc) least significant byte 0000 0000 0000 0000 103h (2) status ? ? ?to pd zdcc ---1 1000 ---q quuu 104h (2) fsr0l indirect data memory address 0 low pointer 0000 0000 uuuu uuuu 105h (2) fsr0h indirect data memory address 0 high pointer 0000 0000 0000 0000 106h (2) fsr1l indirect data memory address 1 low pointer 0000 0000 uuuu uuuu 107h (2) fsr1h indirect data memory address 1 high pointer 0000 0000 0000 0000 108h (2) bsr ? ? ? bsr<4:0> ---0 0000 ---0 0000 109h (2) wreg working register 0000 0000 uuuu uuuu 10ah (1, 2) pclath ? write buffer for the upper 7 bits of the program counter -000 0000 -000 0000 10bh (2) intcon gie peie tmr0ie inte iocie tmr0if intf iocif 0000 000x 0000 000u 10ch lata porta data latch xxxx xxxx uuuu uuuu 10dh latb portb data latch xxxx xxxx uuuu uuuu 10eh latc portc data latch xxxx xxxx uuuu uuuu 10fh latd portd data latch xxxx xxxx uuuu uuuu 110h late porte data latch xxxx xxxx uuuu uuuu 111h cm1con0 c1on c1out c1oe c1pol ? c1sp c1hys c1sync 0000 -100 0000 -100 112h cm1con1 c1intp c1intn c1pch1 c1pch0 ? ? c1nch<1:0> 0000 --00 0000 --00 113h cm2con0 c2on c2out c2oe c2pol ? c2sp c2hys c2sync 0000 -100 0000 -100 114h cm2con1 c2intp c2intn c2pch1 c2pch0 ? ? c2nch<1:0> 0000 --00 0000 --00 115h cmout ? ? ? ? ? mc3out mc2out mc1out ---- -000 ---- -000 116h borcon sboren ? ? ? ? ? ? borrdy 1--- ---q u--- ---u 117h fvrcon fvren fvrrdy tsen tsrng cdafvr1 cdafvr0 adfvr<1:0> 0q00 0000 0q00 0000 118h daccon0 dacen daclps dacoe ? dacpss<1:0> ? dacnss 000- 00-0 000- 00-0 119h daccon1 ? ? ? dacr<4:0> ---0 0000 ---0 0000 11ah srcon0 srlen srclk2 srclk1 srclk0 srqen srnqen srps srpr 0000 0000 0000 0000 11bh srcon1 srspe srscke srsc2e srsc1e srrpe srrcke srrc2e srrc1e 0000 0000 0000 0000 11ch ? unimplemented ? ? 11dh apfcon p3csel p3bsel p2dsel p2csel p2bsel ccp2sel p1csel p1bsel 0000 0000 0000 0000 11eh cm3con0 c3on c3out c3oe c3pol ? c3sp c3hys c3sync 0000 -100 0000 -100 11fh cm3con1 c3intp c3intn c3pch1 c3pch0 ? ? c3nch<1:0> 0000 --00 0000 --00 table 3-9: special function register summary (continued) address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
pic16(l)f1946/1947 ds41414c-page 36 preliminary ? 2010-2011 microchip technology inc. bank 3 180h (2) indf0 addressing this location uses contents of fsr0h/fsr0l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 181h (2) indf1 addressing this location uses contents of fsr1h/fsr1l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 182h (2) pcl program counter (pc) least significant byte 0000 0000 0000 0000 183h (2) status ? ? ?to pd zdcc ---1 1000 ---q quuu 184h (2) fsr0l indirect data memory address 0 low pointer 0000 0000 uuuu uuuu 185h (2) fsr0h indirect data memory address 0 high pointer 0000 0000 0000 0000 186h (2) fsr1l indirect data memory address 1 low pointer 0000 0000 uuuu uuuu 187h (2) fsr1h indirect data memory address 1 high pointer 0000 0000 0000 0000 188h (2) bsr ? ? ? bsr<4:0> ---0 0000 ---0 0000 189h (2) wreg working register 0000 0000 uuuu uuuu 18ah (1, 2) pclath ? write buffer for the upper 7 bits of the program counter -000 0000 -000 0000 18bh (2) intcon gie peie tmr0ie inte iocie tmr0if intf iocif 0000 000x 0000 000u 18ch ansela ? ? ansa5 ? ansa3 ansa2 ansa1 ansa0 --1- 1111 --1- 1111 18dh ? unimplemented ? ? 18eh ? unimplemented ? ? 18fh ? unimplemented ? ? 190h ansele ? ? ? ? ? anse2 anse1 anse0 ---- -111 ---- -111 191h eeadrl eeprom / program memory address register low byte 0000 0000 0000 0000 192h eeadrh ? eeprom / program memory address register high byte -000 0000 -000 0000 193h eedatl eeprom / program memory read data register low byte xxxx xxxx uuuu uuuu 194h eedath ? ? eeprom / program memory read data register high byte --xx xxxx --uu uuuu 195h eecon1 eepgd cfgs lwlo free wrerr wren wr rd 0000 x000 0000 q000 196h eecon2 eeprom control register 2 0000 0000 0000 0000 197h ? unimplemented ? ? 198h ? unimplemented ? ? 199h rcreg usart receive data register 0000 0000 0000 0000 19ah txreg usart transmit data register 0000 0000 0000 0000 19bh sp1brgl eusart1 baud rate generator, low byte 0000 0000 0000 0000 19ch sp1brgh eusart1 baud rate generator, high byte 0000 0000 0000 0000 19dh rcsta spen rx9 sren cren adden ferr oerr rx9d 0000 000x 0000 000x 19eh txsta csrc tx9 txen sync sendb brgh trmt tx9d 0000 0010 0000 0010 19fh baud1con abdovf rcidl ? sckp brg16 ? wue abden 01-0 0-00 01-0 0-00 table 3-9: special function register summary (continued) address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 37 pic16(l)f1946/1947 bank 4 200h (2) indf0 addressing this location uses contents of fsr0h/fsr0l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 201h (2) indf1 addressing this location uses contents of fsr1h/fsr1l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 202h (2) pcl program counter (pc) least significant byte 0000 0000 0000 0000 203h (2) status ? ? ?to pd zdcc ---1 1000 ---q quuu 204h (2) fsr0l indirect data memory address 0 low pointer 0000 0000 uuuu uuuu 205h (2) fsr0h indirect data memory address 0 high pointer 0000 0000 0000 0000 206h (2) fsr1l indirect data memory address 1 low pointer 0000 0000 uuuu uuuu 207h (2) fsr1h indirect data memory address 1 high pointer 0000 0000 0000 0000 208h (2) bsr ? ? ? bsr<4:0> ---0 0000 ---0 0000 209h (2) wreg working register 0000 0000 uuuu uuuu 20ah (1, 2) pclath ? write buffer for the upper 7 bits of the program counter -000 0000 -000 0000 20bh (2) intcon gie peie tmr0ie inte iocie tmr0if intf iocif 0000 000x 0000 000u 20ch ? unimplemented ? ? 20dh wpub wpub7 wpub6 wpub5 wpub4 wpub3 wpub2 wpub1 wpub0 1111 1111 1111 1111 20eh ? unimplemented ? ? 20fh ? unimplemented ? ? 210h ? unimplemented ? ? 211h ssp1buf synchronous serial port receive buffer/transmit register xxxx xxxx uuuu uuuu 212h ssp1add add<7:0> 0000 0000 0000 0000 213h ssp1msk msk<7:0> 1111 1111 1111 1111 214h ssp1stat smp cke d/a psr/w ua bf 0000 0000 0000 0000 215h ssp1con1 wcol sspov sspen ckp sspm<3:0> 0000 0000 0000 0000 216h ssp1con2 gcen ackstat ackdt acken rcen pen rsen sen 0000 0000 0000 0000 217h ssp1con3 acktim pcie scie boen sdaht sbcde ahen dhen 0000 0000 0000 0000 218h ? unimplemented ? ? 219h ssp2buf synchronous serial port receive buffer/transmit register xxxx xxxx uuuu uuuu 21ah ssp2add add<7:0> 0000 0000 0000 0000 21bh ssp2msk msk<7:0> 1111 1111 1111 1111 21ch ssp2stat smp cke d/a psr/w ua bf 0000 0000 0000 0000 21dh ssp2con1 wcol sspov sspen ckp sspm<3:0> 0000 0000 0000 0000 21eh ssp2con2 gcen ackstat ackdt acken rcen pen rsen sen 0000 0000 0000 0000 21fh ssp2con3 acktim pcie scie boen sdaht sbcde ahen dhen 0000 0000 0000 0000 table 3-9: special function register summary (continued) address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
pic16(l)f1946/1947 ds41414c-page 38 preliminary ? 2010-2011 microchip technology inc. bank 5 280h (2) indf0 addressing this location uses contents of fsr0h/fsr0l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 281h (2) indf1 addressing this location uses contents of fsr1h/fsr1l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 282h (2) pcl program counter (pc) least significant byte 0000 0000 0000 0000 283h (2) status ? ? ?to pd zdcc ---1 1000 ---q quuu 284h (2) fsr0l indirect data memory address 0 low pointer 0000 0000 uuuu uuuu 285h (2) fsr0h indirect data memory address 0 high pointer 0000 0000 0000 0000 286h (2) fsr1l indirect data memory address 1 low pointer 0000 0000 uuuu uuuu 287h (2) fsr1h indirect data memory address 1 high pointer 0000 0000 0000 0000 288h (2) bsr ? ? ? bsr<4:0> ---0 0000 ---0 0000 289h (2) wreg working register 0000 0000 uuuu uuuu 28ah (1, 2) pclath ? write buffer for the upper 7 bits of the program counter -000 0000 -000 0000 28bh (2) intcon gie peie tmr0ie inte iocie tmr0if intf iocif 0000 000x 0000 000u 28ch portf portf data latch when written: portf pins when read xxxx xxxx uuuu uuuu 28dh portg ? ? rg5 rg4 rg3 rg2 rg1 rg0 --xx xxxx --uu uuuu 28eh ? unimplemented ? ? 28fh ? unimplemented ? ? 290h ? unimplemented ? ? 291h ccpr1l capture/compare/pwm register 1 (lsb) xxxx xxxx uuuu uuuu 292h ccpr1h capture/compare/pwm register 1 (msb) xxxx xxxx uuuu uuuu 293h ccp1con p1m<1:0> dc1b<1:0> ccp1m<3:0> 0000 0000 0000 0000 294h pwm1con p1rsen p1dc<6:0> 0000 0000 0000 0000 295h ccp1as ccp1ase ccp1as<2:0> pss1ac<1:0> pss1bd<1:0> 0000 0000 0000 0000 296h pstr1con ? ? ? str1sync str1d str1c str1b str1a ---0 0001 ---0 0001 297h ? unimplemented ? ? 298h ccpr2l capture/compare/pwm register 2 (lsb) xxxx xxxx uuuu uuuu 299h ccpr2h capture/compare/pwm register 2 (msb) xxxx xxxx uuuu uuuu 29ah ccp2con p2m<1:0> dc2b<1:0> ccp2m<3:0> 0000 0000 0000 0000 29bh pwm2con p2rsen p2dc<6:0> 0000 0000 0000 0000 29ch ccp2as ccp2ase ccp2as<2:0> pss2ac<1:0> pss2bd<1:0> 0000 0000 0000 0000 29dh pstr2con ? ? ? str2sync str2d str2c str2b str2a ---0 0001 ---0 0001 29eh ccptmrs0 c4tsel1 c4tsel0 c3tsel1 c3tsel0 c2tsel1 c2tsel0 c1tsel1 c1tsel0 0000 0000 0000 0000 29fh ccptmrs1 ? ? ? ? ? ? c5tsel<1:0> ---- --00 ---- --00 table 3-9: special function register summary (continued) address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 39 pic16(l)f1946/1947 bank 6 300h (2) indf0 addressing this location uses contents of fsr0h/fsr0l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 301h (2) indf1 addressing this location uses contents of fsr1h/fsr1l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 302h (2) pcl program counter (pc) least significant byte 0000 0000 0000 0000 303h (2) status ? ? ?to pd zdcc ---1 1000 ---q quuu 304h (2) fsr0l indirect data memory address 0 low pointer 0000 0000 uuuu uuuu 305h (2) fsr0h indirect data memory address 0 high pointer 0000 0000 0000 0000 306h (2) fsr1l indirect data memory address 1 low pointer 0000 0000 uuuu uuuu 307h (2) fsr1h indirect data memory address 1 high pointer 0000 0000 0000 0000 308h (2) bsr ? ? ? bsr<4:0> ---0 0000 ---0 0000 309h (2) wreg working register 0000 0000 uuuu uuuu 30ah (1, 2) pclath ? write buffer for the upper 7 bits of the program counter -000 0000 -000 0000 30bh (2) intcon gie peie tmr0ie inte iocie tmr0if intf iocif 0000 000x 0000 000u 30ch trisf portf data direction register 1111 1111 1111 1111 30dh trisg ? ? trisg5 trisg4 trisg3 t risg2 trisg1 trisg0 --11 1111 --11 1111 30eh ? unimplemented ? ? 30fh ? unimplemented ? ? 310h ? unimplemented ? ? 311h ccpr3l capture/compare/pwm register 3 (lsb) xxxx xxxx uuuu uuuu 312h ccpr3h capture/compare/pwm register 3 (msb) xxxx xxxx uuuu uuuu 313h ccp3con p3m<1:0> dc3b<1:0> ccp3m<1:0> 0000 0000 0000 0000 314h pwm3con p3rsen p3dc<6:0> 0000 0000 0000 0000 315h ccp3as ccp3ase ccp3as<2:0> pss3ac<1:0> pss3bd<1:0> 0000 0000 0000 0000 316h pstr3con ? ? ? str3sync str3d str3c str3b str3a ---0 0001 ---0 0001 317h ? unimplemented ? ? 318h ccpr4l capture/compare/pwm register 4 (lsb) xxxx xxxx uuuu uuuu 319h ccpr4h capture/compare/pwm register 4 (msb) xxxx xxxx uuuu uuuu 31ah ccp4con ? ? dc4b<1:0> ccp4m<3:0> --00 0000 --00 0000 31bh ? unimplemented ? ? 31ch ccpr5l capture/compare/pwm register 5 (lsb) xxxx xxxx uuuu uuuu 31dh ccpr5h capture/compare/pwm register 5 (msb) xxxx xxxx uuuu uuuu 31eh ccp5con ? ? dc5b<1:0> ccp5m<3:0> --00 0000 --00 0000 31fh ? unimplemented ? ? table 3-9: special function register summary (continued) address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
pic16(l)f1946/1947 ds41414c-page 40 preliminary ? 2010-2011 microchip technology inc. bank 7 380h (2) indf0 addressing this location uses contents of fsr0h/fsr0l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 381h (2) indf1 addressing this location uses contents of fsr1h/fsr1l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 382h (2) pcl program counter (pc) least significant byte 0000 0000 0000 0000 383h (2) status ? ? ?to pd zdcc ---1 1000 ---q quuu 384h (2) fsr0l indirect data memory address 0 low pointer 0000 0000 uuuu uuuu 385h (2) fsr0h indirect data memory address 0 high pointer 0000 0000 0000 0000 386h (2) fsr1l indirect data memory address 1 low pointer 0000 0000 uuuu uuuu 387h (2) fsr1h indirect data memory address 1 high pointer 0000 0000 0000 0000 388h (2) bsr ? ? ? bsr<4:0> ---0 0000 ---0 0000 389h (2) wreg working register 0000 0000 uuuu uuuu 38ah (1, 2) pclath ? write buffer for the upper 7 bits of the program counter -000 0000 -000 0000 38bh (2) intcon gie peie tmr0ie inte iocie tmr0if intf iocif 0000 000x 0000 000u 38ch latf portf data latch xxxx xxxx uuuu uuuu 38dh latg ? ? latg5 latg4 latg3 latg2 latg1 latg0 --xx xxxx --uu uuuu 38eh ? unimplemented ? ? 38fh ? unimplemented ? ? 390h ? unimplemented ? ? 391h ? unimplemented ? ? 392h ? unimplemented ? ? 393h ? unimplemented ? ? 394h iocbp iocbp7 iocbp6 iocbp5 iocbp4 iocbp3 iocbp2 iocbp1 iocbp0 0000 0000 0000 0000 395h iocbn iocbn7 iocbn6 iocbn5 iocbn4 iocbn3 iocbn2 iocbn1 iocbn0 0000 0000 0000 0000 396h iocbf iocbf7 iocbf6 iocbf5 iocbf4 iocbf3 iocbf2 iocbf1 iocbf0 0000 0000 0000 0000 397h ? unimplemented ? ? 398h ? unimplemented ? ? 399h ? unimplemented ? ? 39ah ? unimplemented ? ? 39bh ? unimplemented ? ? 39ch ? unimplemented ? ? 39dh ? unimplemented ? ? 39eh ? unimplemented ? ? 39fh ? unimplemented ? ? table 3-9: special function register summary (continued) address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 41 pic16(l)f1946/1947 bank 8 400h (2) indf0 addressing this location uses contents of fsr0h/fsr0l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 401h (2) indf1 addressing this location uses contents of fsr1h/fsr1l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 402h (2) pcl program counter (pc) least significant byte 0000 0000 0000 0000 403h (2) status ? ? ?to pd zdcc ---1 1000 ---q quuu 404h (2) fsr0l indirect data memory address 0 low pointer 0000 0000 uuuu uuuu 405h (2) fsr0h indirect data memory address 0 high pointer 0000 0000 0000 0000 406h (2) fsr1l indirect data memory address 1 low pointer 0000 0000 uuuu uuuu 407h (2) fsr1h indirect data memory address 1 high pointer 0000 0000 0000 0000 408h (2) bsr ? ? ? bsr<4:0> ---0 0000 ---0 0000 409h (2) wreg working register 0000 0000 uuuu uuuu 40ah (1, 2) pclath ? write buffer for the upper 7 bits of the program counter -000 0000 -000 0000 40bh (2) intcon gie peie tmr0ie inte iocie tmr0if intf iocif 0000 000x 0000 000u 40ch anself anself7 anself6 anself5 an self4 anself3 anself2 anself1 anself0 1111 1111 1111 1111 40dh anselg ? ? ? anselg4 anselg3 anselg2 anselg1 ? ---1 111- ---1 111- 40eh ? unimplemented ? ? 40fh ? unimplemented ? ? 410h ? unimplemented ? ? 411h ? unimplemented ? ? 412h ? unimplemented ? ? 413h ? unimplemented ? ? 414h ? unimplemented ? ? 415h tmr4 timer 4 module register 0000 0000 0000 0000 416h pr4 timer 4 period register 1111 1111 1111 1111 417h t4con ? t4outps<3:0> tmr4on t4ckps <1:0> -000 0000 -000 0000 418h ? unimplemented ? ? 419h ? unimplemented ? ? 41ah ? unimplemented ? ? 41bh ? unimplemented ? ? 41ch tmr6 timer 6 module register 0000 0000 0000 0000 41dh pr6 timer 6 period register 1111 1111 1111 1111 41eh t6con ? t6outps<3:0> tmr6on t6ckps <1:0> -000 0000 -000 0000 41fh ? unimplemented ? ? table 3-9: special function register summary (continued) address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
pic16(l)f1946/1947 ds41414c-page 42 preliminary ? 2010-2011 microchip technology inc. bank 9 480h (2) indf0 addressing this location uses contents of fsr0h/fsr0l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 481h (2) indf1 addressing this location uses contents of fsr1h/fsr1l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 482h (2) pcl program counter (pc) least significant byte 0000 0000 0000 0000 483h (2) status ? ? ?to pd zdcc ---1 1000 ---q quuu 404h (2) fsr0l indirect data memory address 0 low pointer 0000 0000 uuuu uuuu 485h (2) fsr0h indirect data memory address 0 high pointer 0000 0000 0000 0000 486h (2) fsr1l indirect data memory address 1 low pointer 0000 0000 uuuu uuuu 487h (2) fsr1h indirect data memory address 1 high pointer 0000 0000 0000 0000 488h (2) bsr ? ? ? bsr<4:0> ---0 0000 ---0 0000 489h (2) wreg working register 0000 0000 uuuu uuuu 48ah (1, 2) pclath ? write buffer for the upper 7 bits of the program counter -000 0000 -000 0000 48bh (2) intcon gie peie tmr0ie inte iocie tmr0if intf iocif 0000 000x 0000 000u 48ch ? unimplemented ? ? 48dh wpug ? ?wpug5 ? ? ? ? ? --1- ---- --1- ---- 48eh ? unimplemented ? ? 48fh ? unimplemented ? ? 490h ? unimplemented ? ? 491h rc2reg usart receive data register 0000 0000 0000 0000 492h tx2reg usart transmit data register 0000 0000 0000 0000 493h sp2brgl eusart2 baud rate generator, low byte 0000 0000 0000 0000 494h sp2brgh eusart2 baud rate generator, high byte 0000 0000 0000 0000 495h rc2sta spen rx9 sren cren adden ferr oerr rx9d 0000 000x 0000 000x 496h tx2sta csrc tx9 txen sync sendb brgh trmt tx9d 0000 0010 0000 0010 497h baudcon2 abdovf rcidl ? sckp brg16 ? wue abden 01-0 0-00 01-0 0-00 498h ? unimplemented ? ? 499h ? unimplemented ? ? 49ah ? unimplemented ? ? 49bh ? unimplemented ? ? 49ch ? unimplemented ? ? 49dh ? unimplemented ? ? 49eh ? unimplemented ? ? 49fh ? unimplemented ? ? table 3-9: special function register summary (continued) address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 43 pic16(l)f1946/1947 banks 10-14 x00h/ x80h (2) indf0 addressing this location uses contents of fsr0h/fsr0l to address data memory (not a physical register) xxxx xxxx xxxx xxxx x00h/ x81h (2) indf1 addressing this location uses contents of fsr1h/fsr1l to address data memory (not a physical register) xxxx xxxx xxxx xxxx x02h/ x82h (2) pcl program counter (pc) least significant byte 0000 0000 0000 0000 x03h/ x83h (2) status ? ? ?to pd zdcc ---1 1000 ---q quuu x04h/ x84h (2) fsr0l indirect data memory address 0 low pointer 0000 0000 uuuu uuuu x05h/ x85h (2) fsr0h indirect data memory address 0 high pointer 0000 0000 0000 0000 x06h/ x86h (2) fsr1l indirect data memory address 1 low pointer 0000 0000 uuuu uuuu x07h/ x87h (2) fsr1h indirect data memory address 1 high pointer 0000 0000 0000 0000 x08h/ x88h (2) bsr ? ? ? bsr<4:0> ---0 0000 ---0 0000 x09h/ x89h (2) wreg working register 0000 0000 uuuu uuuu x0ah/ x8ah (1),(2) pclath ? write buffer for the upper 7 bits of the program counter -000 0000 -000 0000 x0bh/ x8bh (2) intcon gie peie tmr0ie inte iocie tmr0if intf iocif 0000 000x 0000 000u x0ch/ x8ch ? x1fh/ x9fh ? unimplemented ? ? table 3-9: special function register summary (continued) address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
pic16(l)f1946/1947 ds41414c-page 44 preliminary ? 2010-2011 microchip technology inc. bank 15 780h (2) indf0 addressing this location uses contents of fsr0h/fsr0l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 781h (2) indf1 addressing this location uses contents of fsr1h/fsr1l to address data memory (not a physical register) xxxx xxxx xxxx xxxx 782h (2) pcl program counter (pc) least significant byte 0000 0000 0000 0000 783h (2) status ? ? ?to pd zdcc ---1 1000 ---q quuu 784h (2) fsr0l indirect data memory address 0 low pointer 0000 0000 uuuu uuuu 785h (2) fsr0h indirect data memory address 0 high pointer 0000 0000 0000 0000 786h (2) fsr1l indirect data memory address 1 low pointer 0000 0000 uuuu uuuu 787h (2) fsr1h indirect data memory address 1 high pointer 0000 0000 0000 0000 788h (2) bsr ? ? ? bsr<4:0> ---0 0000 ---0 0000 789h (2) wreg working register 0000 0000 uuuu uuuu 78ah (1, 2) pclath ? write buffer for the upper 7 bits of the program counter -000 0000 -000 0000 78bh (2) intcon gie peie tmr0ie inte iocie tmr0if intf iocif 0000 000x 0000 000u 78ch ? unimplemented ? ? 78dh ? unimplemented ? ? 78eh ? unimplemented ? ? 78fh ? unimplemented ? ? 790h ? unimplemented ? ? 791h lcdcon lcden slpen werr ?cs <1:0> lmux <1:0> 000- 0011 000- 0011 792h lcdps wft biasmd lcda wa lp <3:0> 0000 0000 0000 0000 793h lcdref lcdire lcdirs lcdiri ? vlcd3pe vlcd2pe vlcd1pe ? 000- 000- 000- 000- 794h lcdcst ? ? ? ? ? lcdcst <2:0> ---- -000 ---- -000 795h lcdrl lrlap <1:0> lrlbp <1:0> ?lrlat <2:0> 0000 -000 0000 -000 796h ? unimplemented ? ? 797h ? unimplemented ? ? 798h lcdse0 se<7:0> 0000 0000 uuuu uuuu 799h lcdse1 se<15:8> 0000 0000 uuuu uuuu 79ah lcdse2 se<23:16> 0000 0000 uuuu uuuu 79bh lcdse3 se<31:24> 0000 0000 uuuu uuuu 79ch lcdse4 se<39:32> 0000 0000 uuuu uuuu 79dh lcdse5 ? ? se<45:40> --00 0000 --uu uuuu 79eh ? unimplemented ? ? 79fh ? unimplemented ? ? 7a0h lcddata0 seg7 com0 seg6 com0 seg5 com0 seg4 com0 seg3 com0 seg2 com0 seg1 com0 seg0 com0 xxxx xxxx uuuu uuuu 7a1h lcddata1 seg15 com0 seg14 com0 seg13 com0 seg12 com0 seg11 com0 seg10 com0 seg9 com0 seg8 com0 xxxx xxxx uuuu uuuu 7a2h lcddata2 seg23 com0 seg22 com0 seg21 com0 seg20 com0 seg19 com0 seg18 com0 seg17 com0 seg16 com0 xxxx xxxx uuuu uuuu 7a3h lcddata3 seg7 com1 seg6 com1 seg5 com1 seg4 com1 seg3 com1 seg2 com1 seg1 com1 seg0 com1 xxxx xxxx uuuu uuuu 7a4h lcddata4 seg15 com1 seg14 com1 seg13 com1 seg12 com1 seg11 com1 seg10 com1 seg9 com1 seg8 com1 xxxx xxxx uuuu uuuu 7a5h lcddata5 seg23 com1 seg22 com1 seg21 com1 seg20 com1 seg19 com1 seg18 com1 seg17 com1 seg16 com1 xxxx xxxx uuuu uuuu table 3-9: special function register summary (continued) address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 45 pic16(l)f1946/1947 bank 15 (continued) 7a6h lcddata6 seg7 com2 seg6 com2 seg5 com2 seg4 com2 seg3 com2 seg2 com2 seg1 com2 seg0 com2 xxxx xxxx uuuu uuuu 7a7h lcddata7 seg15 com2 seg14 com2 seg13 com2 seg12 com2 seg11 com2 seg10 com2 seg9 com2 seg8 com2 xxxx xxxx uuuu uuuu 7a8h lcddata8 seg23 com2 seg22 com2 seg21 com2 seg20 com2 seg19 com2 seg18 com2 seg17 com2 seg16 com2 xxxx xxxx uuuu uuuu 7a9h lcddata9 seg7 com3 seg6 com3 seg5 com3 seg4 com3 seg3 com3 seg2 com3 seg1 com3 seg0 com3 xxxx xxxx uuuu uuuu 7aah lcddata10 seg15 com3 seg14 com3 seg13 com3 seg12 com3 seg11 com3 seg10 com3 seg9 com3 seg8 com3 xxxx xxxx uuuu uuuu 7abh lcddata11 seg23 com3 seg22 com3 seg21 com3 seg20 com3 seg19 com3 seg18 com3 seg17 com3 seg16 com3 xxxx xxxx uuuu uuuu 7ach lcddata12 seg31 com0 seg30 com0 seg29 com0 seg28 com0 seg27 com0 seg26 com0 seg25 com0 seg24 com0 xxxx xxxx uuuu uuuu 7adh lcddata13 seg39 com0 seg38 com0 seg37 com0 seg36 com0 seg35 com0 seg34 com0 seg33 com0 seg32 com0 xxxx xxxx uuuu uuuu 7aeh lcddata14 ? ?seg45 com0 seg44 com0 seg43 com0 seg42 com0 seg41 com0 seg40 com0 --xx xxxx --uu uuuu 7afh lcddata15 seg31 com1 seg30 com1 seg29 com1 seg28 com1 seg27 com1 seg26 com1 seg25 com1 seg24 com1 xxxx xxxx uuuu uuuu 7b0h lcddata16 seg39 com1 seg38 com1 seg37 com1 seg36 com1 seg35 com1 seg34 com1 seg33 com1 seg32 com1 xxxx xxxx uuuu uuuu 7b1h lcddata17 ? ?seg45 com1 seg44 com1 seg43 com1 seg42 com1 seg41 com1 seg40 com1 --xx xxxx --uu uuuu 7b2h lcddata18 seg31 com2 seg30 com2 seg29 com2 seg28 com2 seg27 com2 seg26 com2 seg25 com2 seg24 com2 xxxx xxxx uuuu uuuu 7b3h lcddata19 seg39 com2 seg38 com2 seg37 com2 seg36 com2 seg35 com2 seg34 com2 seg33 com2 seg32 com2 xxxx xxxx uuuu uuuu 7b4h lcddata20 ? ?seg45 com2 seg44 com2 seg43 com2 seg42 com2 seg41 com2 seg40 com2 --xx xxxx --uu uuuu 7b5h lcddata21 seg31 com3 seg30 com3 seg29 com3 seg28 com3 seg27 com3 seg26 com3 seg25 com3 seg24 com3 xxxx xxxx uuuu uuuu 7b6h lcddata22 seg39 com3 seg38 com3 seg37 com3 seg36 com3 seg35 com3 seg34 com3 seg33 com3 seg32 com3 xxxx xxxx uuuu uuuu 7b7h lcddata23 ? ?seg45 com3 seg44 com3 seg43 com3 seg42 com3 seg41 com3 seg40 com3 --xx xxxx --uu uuuu 7b8h ? 7efh ? unimplemented ? ? table 3-9: special function register summary (continued) address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
pic16(l)f1946/1947 ds41414c-page 46 preliminary ? 2010-2011 microchip technology inc. banks 16-30 x00h/ x80h (2) indf0 addressing this location uses contents of fsr0h/fsr0l to address data memory (not a physical register) xxxx xxxx xxxx xxxx x00h/ x81h (2) indf1 addressing this location uses contents of fsr1h/fsr1l to address data memory (not a physical register) xxxx xxxx xxxx xxxx x02h/ x82h (2) pcl program counter (pc) least significant byte 0000 0000 0000 0000 x03h/ x83h (2) status ? ? ?to pd zdcc ---1 1000 ---q quuu x04h/ x84h (2) fsr0l indirect data memory address 0 low pointer 0000 0000 uuuu uuuu x05h/ x85h (2) fsr0h indirect data memory address 0 high pointer 0000 0000 0000 0000 x06h/ x86h (2) fsr1l indirect data memory address 1 low pointer 0000 0000 uuuu uuuu x07h/ x87h (2) fsr1h indirect data memory address 1 high pointer 0000 0000 0000 0000 x08h/ x88h (2) bsr ? ? ? bsr<4:0> ---0 0000 ---0 0000 x09h/ x89h (2) wreg working register 0000 0000 uuuu uuuu x0ah/ x8ah (1),(2) pclath ? write buffer for the upper 7 bits of the program counter -000 0000 -000 0000 x0bh/ x8bh (2) intcon gie peie tmr0ie inte iocie tmr0if intf iocif 0000 000x 0000 000u x0ch/ x8ch ? x1fh/ x9fh ? unimplemented ? ? table 3-9: special function register summary (continued) address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 47 pic16(l)f1946/1947 bank 31 f80h (2) indf0 addressing this location uses contents of fsr0h/fsr0l to address data memory (not a physical register) xxxx xxxx xxxx xxxx f81h (2) indf1 addressing this location uses contents of fsr1h/fsr1l to address data memory (not a physical register) xxxx xxxx xxxx xxxx f82h (2) pcl program counter (pc) least significant byte 0000 0000 0000 0000 f83h (2) status ? ? ?to pd zdcc ---1 1000 ---q quuu f84h (2) fsr0l indirect data memory address 0 low pointer 0000 0000 uuuu uuuu f85h (2) fsr0h indirect data memory address 0 high pointer 0000 0000 0000 0000 f86h (2) fsr1l indirect data memory address 1 low pointer 0000 0000 uuuu uuuu f87h (2) fsr1h indirect data memory address 1 high pointer 0000 0000 0000 0000 f88h (2) bsr ? ? ? bsr<4:0> ---0 0000 ---0 0000 f89h (2) wreg working register 0000 0000 uuuu uuuu f8ah (1),(2 ) pclath ? write buffer for the upper 7 bits of the program counter -000 0000 -000 0000 f8bh (2) intcon gie peie tmr0ie inte iocie tmr0if intf iocif 0000 000x 0000 000u f8ch ? fe3h ? unimplemented ? ? fe4h status_ shad zdcc ---- -xxx ---- -uuu fe5h wreg_ shad working register normal (non-icd) shadow xxxx xxxx uuuu uuuu fe6h bsr_ shad bank select register normal (non-icd) shadow ---x xxxx ---u uuuu fe7h pclath_ shad program counter latch high register normal (non-icd) shadow -xxx xxxx uuuu uuuu fe8h fsr0l_ shad indirect data memory address 0 low pointer normal (non-icd) shadow xxxx xxxx uuuu uuuu fe9h fsr0h_ shad indirect data memory address 0 high pointer normal (non-icd) shadow xxxx xxxx uuuu uuuu feah fsr1l_ shad indirect data memory address 1 low pointer normal (non-icd) shadow xxxx xxxx uuuu uuuu febh fsr1h_ shad indirect data memory address 1 high pointer normal (non-icd) shadow xxxx xxxx uuuu uuuu fech ? unimplemented ? ? fedh stkptr ? ? ? current stack pointer ---1 1111 ---1 1111 feeh tosl top of stack low byte xxxx xxxx uuuu uuuu fefh tosh ? top of stack high byte -xxx xxxx -uuu uuuu table 3-9: special function register summary (continued) address name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 value on por, bor value on all other resets legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented, read as ? 0 ?, r = reserved. shaded locations are unimplemented, read as ? 0 ?. note 1: the upper byte of the program counter is not directly accessible. pclath is a holding register for the pc<14:8>, whose contents are transferred to the upper byte of the program counter. 2: these registers can be addressed from any bank.
pic16(l)f1946/1947 ds41414c-page 48 preliminary ? 2010-2011 microchip technology inc. 3.3 pcl and pclath the program counter (pc) is 15 bits wide. the low byte comes from the pcl register, which is a readable and writable register. the high byte (pc<14:8>) is not directly readable or writable and comes from pclath. on any reset, the pc is cleared. figure 3-4 shows the five situations for the loading of the pc. figure 3-4: loading of pc in different situations 3.3.1 modifying pcl executing any instruction with the pcl register as the destination simultaneously causes the program coun- ter pc<14:8> bits (pch) to be replaced by the contents of the pclath register. this allows the entire contents of the program counter to be changed by writing the desired upper 7 bits to the pclath register. when the lower 8 bits are written to the pcl register, all 15 bits of the program counter will change to the values con- tained in the pclath register and those being written to the pcl register. 3.3.2 computed goto a computed goto is accomplished by adding an offset to the program counter ( addwf pcl ). when performing a table read using a computed goto method, care should be exercised if the table location crosses a pcl memory boundary (each 256-byte block). refer to the application note an556, ?implementing a table read? (ds00556). 3.3.3 computed function calls a computed function call allows programs to maintain tables of functions and provide another way to execute state machines or look-up tables. when performing a table read using a computed function call , care should be exercised if the table location crosses a pcl memory boundary (each 256-byte block). if using the call instruction, the pch<2:0> and pcl registers are loaded with the operand of the call instruction. pch<6:3> is loaded with pclath<6:3>. the callw instruction enables computed calls by com- bining pclath and w to form the destination address. a computed callw is accomplished by loading the w register with the desired address and executing callw . the pcl register is loaded with the value of w and pch is loaded with pclath. 3.3.4 branching the branching instructions add an offset to the pc. this allows relocatable code and code that crosses page boundaries. there are two forms of branching, brw and bra . the pc will have incremented to fetch the next instruction in both cases. when using either branching instruction, a pcl memory boundary may be crossed. if using brw , load the w register with the desired unsigned address and execute brw . the entire pc will be loaded with the address pc + 1 + w. if using bra , the entire pc will be loaded with pc + 1 +, the signed value of the operand of the bra instruction. pcl pch 0 14 pc 0 6 7 alu result 8 pclath pcl pch 0 14 pc 0 6 4 opcode <10:0> 11 pclath pcl pch 0 14 pc 0 6 7 w 8 pclath instruction with pcl as destination goto, call callw pcl pch 0 14 pc pc + w 15 brw pcl pch 0 14 pc pc + opcode <8:0> 15 bra
? 2010-2011 microchip technology inc. preliminary ds41414c-page 49 pic16(l)f1946/1947 3.4 stack all devices have a 16-level x 15-bit wide hardware stack (refer to figures 3-3 and 3-4 ). the stack space is not part of either program or data space. the pc is pushed onto the stack when call or callw instruc- tions are executed or an interrupt causes a branch. the stack is poped in the event of a return , retlw or a retfie instruction execution. pclath is not affected by a push or pop operation. the stack operates as a circular buffer if the stvren bit is programmed to ? 0 ? (configuration word 2). this means that after the stack has been pushed sixteen times, the seventeenth push overwrites the value that was stored from the first push. the eighteenth push overwrites the second push (and so on). the stkovf and stkunf flag bits will be set on an over- flow/underflow, regardless of whether the reset is enabled. 3.4.1 accessing the stack the stack is available through the tosh, tosl and stkptr registers. stkptr is the current value of the stack pointer. tosh:tosl register pair points to the top of the stack. both registers are read/writable. tos is split into tosh and tosl due to the 15-bit size of the pc. to access the stack, adjust the value of stkptr, which will position tosh:tosl, then read/write to tosh:tosl. stkptr is 5 bits to allow detection of overflow and underflow. during normal program operation, call, callw and interrupts will increment stkptr while retlw , return , and retfie will decrement stkptr. at any time stkptr can be inspected to see how much stack is left. the stkptr always points at the currently used place on the stack. therefore, a call or callw will increment the stkptr and then write the pc, and a return will unload the pc and then decrement the stk- ptr. reference figure through figure for examples of accessing the stack. figure 3-5: accessing the stack example 1 note 1: there are no instructions/mnemonics called push or pop. these are actions that occur from the execution of the call, callw , return , retlw and retfie instructions or the vectoring to an interrupt address. note: care should be taken when modifying the stkptr while interrupts are enabled. 0x0f 0x0e 0x0d 0x0c 0x0b 0x0a 0x09 0x08 0x07 0x06 0x05 0x04 0x03 0x02 0x01 0x00 0x0000 stkptr = 0x1f initial stack configuration: after reset, the stack is empty. the empty stack is initialized so the stack pointer is pointing at 0x1f. if the stack overflow/underflow reset is enabled, the tosh/tosl registers will return ? 0 ?. if the stack overflow/underflow reset is disabled, the tosh/tosl registers will return the contents of stack address 0x0f. 0x1f stkptr = 0x1f stack reset disabled (stvren = 0 ) stack reset enabled (stvren = 1 ) tosh:tosl tosh:tosl
pic16(l)f1946/1947 ds41414c-page 50 preliminary ? 2010-2011 microchip technology inc. figure 3-6: accessing the stack example 2 figure 3-7: accessing the stack example 3 0x0f 0x0e 0x0d 0x0c 0x0b 0x0a 0x09 0x08 0x07 0x06 0x05 0x04 0x03 0x02 0x01 return address 0x00 stkptr = 0x00 this figure shows the stack configuration after the first call or a single interrupt. if a return instruction is executed, the return addre ss will be placed in the program counter and the stack pointer decremented to the empty state (0x1f). tosh:tosl 0x0f 0x0e 0x0d 0x0c 0x0b 0x0a 0x09 0x08 0x07 return address 0x06 return address 0x05 return address 0x04 return address 0x03 return address 0x02 return address 0x01 return address 0x00 stkptr = 0x06 after seven call s or six call s and an interrupt, the stack looks like the figure on the left. a series of return instructions will repeatedly place the return addresses into the program counter and pop the stack. tosh:tosl
? 2010-2011 microchip technology inc. preliminary ds41414c-page 51 pic16(l)f1946/1947 figure 3-8: accessing the stack example 4 3.4.2 overflow/ underflow reset if the stvren bit in configuration word 2 is programmed to ? 1 ?, the device will be reset if the stack is pushed beyond the sixteenth level or poped beyond the first level, setting the appropriate bits (stkovf or stkunf, respectively) in the pcon register. 3.5 indirect addressing the indfn registers are not physical registers. any instruction that accesses an indfn register actually accesses the register at the address specified by the file select registers (fsr). if the fsrn address specifies one of the two indfn registers, the read will return ? 0 ? and the write will not occur (though status bits may be affected). the fsrn register value is created by the pair fsrnh and fsrnl. the fsr registers form a 16- bit address that allows an addressing space with 65536 locations. these locations are divided into three memory regions: ? traditional data memory ? linear data memory ? program flash memory 0x0f 0x0e 0x0d 0x0c 0x0b 0x0a 0x09 0x08 0x07 0x06 0x05 0x04 0x03 0x02 0x01 return address 0x00 stkptr = 0x10 when the stack is full, the next call or an interrupt will set the stack pointer to 0x10. this is identical to address 0x00 so the stack will wrap and overwrite the return address at 0x00. if the stack overflow/underflow reset is enabled, a reset will occur and location 0x00 will not be overwritten. return address return address return address return address return address return address return address return address return address return address return address return address return address return address return address tosh:tosl
pic16(l)f1946/1947 ds41414c-page 52 preliminary ? 2010-2011 microchip technology inc. figure 3-9: indirect addressing 0x0000 0x0fff traditional fsr address range data memory 0x1000 reserved linear data memory reserved 0x2000 0x29af 0x29b0 0x7fff 0x8000 0xffff 0x0000 0x0fff 0x0000 0x7fff program flash memory note: not all memory regions are completely implemented. consult device memory tables for memory limits. 0x1fff
? 2010-2011 microchip technology inc. preliminary ds41414c-page 53 pic16(l)f1946/1947 3.5.1 traditional data memory the traditional data memory is a region from fsr address 0x000 to fsr address 0xfff. the addresses correspond to the absolute addresses of all sfr, gpr and common registers. figure 3-10: traditio nal data memory map indirect addressing direct addressing bank select location select 4bsr 6 0 from opcode fsrxl 70 bank select location select 00000 00001 00010 11111 0x00 0x7f bank 0 bank 1 bank 2 bank 31 0 fsrxh 70 0000
pic16(l)f1946/1947 ds41414c-page 54 preliminary ? 2010-2011 microchip technology inc. 3.5.2 linear data memory the linear data memory is the region from fsr address 0x2000 to fsr address 0x29af. this region is a virtual region that points back to the 80-byte blocks of gpr memory in all the banks. unimplemented memory reads as 0x00. use of the linear data memory region allows buffers to be larger than 80 bytes because incrementing the fsr beyond one bank will go directly to the gpr memory of the next bank. the 16 bytes of common memory are not included in the linear data memory region. figure 3-11: linear data memory map 3.5.3 program flash memory to make constant data access easier, the entire program flash memory is mapped to the upper half of the fsr address space. when the msb of fsrnh is set, the lower 15 bits are the address in program memory which will be accessed through indf. only the lower 8 bits of each memory location is accessible via indf. writing to the program flash memory cannot be accomplished via the fsr/indf interface. all instructions that access program flash memory via the fsr/indf interface will require one additional instruction cycle to complete. figure 3-12: program flash memory map 7 0 1 7 0 0 location select 0x2000 fsrnh fsrnl 0x020 bank 0 0x06f 0x0a0 bank 1 0x0ef 0x120 bank 2 0x16f 0xf20 bank 30 0xf6f 0x29af 0 7 1 7 0 0 location select 0x8000 fsrnh fsrnl 0x0000 0x7fff 0xffff program flash memory (low 8 bits)
? 2010-2011 microchip technology inc. preliminary ds41414c-page 55 pic16(l)f1946/1947 4.0 device configuration device configuration consists of configuration word 1 and configuration word 2 registers, code protection and device id. 4.1 configuration words there are several configuration word bits that allow different oscillator and memory protection options. these are implemented as configuration word 1 at 8007h and configuration word 2 at 8008h. note: the debug bit in configuration word 2 is managed automatically by device development tools including debuggers and programmers. for normal device operation, this bit should be maintained as a ' 1 '.
pic16(l)f1946/1947 ds41414c-page 56 preliminary ? 2010-2011 microchip technology inc. 4.2 configuration word registers register 4-1: co nfiguration word 1 r/p-1/1 r/p-1/1 r/p-1/1 r/p-1/1 r/p-1/1 r/p-1/1 r/p-1/1 fcmen ieso clkouten boren1 boren0 cpd cp bit 13 bit 7 r/p-1/1 r/p-1/1 r/p-1/1 r/p-1/1 r/p-1/1 r/p-1/1 r/p-1/1 mclre pwrte wdte1 wdte0 fosc2 fosc1 fosc0 bit 6 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?1? u = bit is unchanged x = bit is unknown -n/n = va lue at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared p = programmable bit bit 13 fcmen: fail-safe clock monitor enable bit 1 = fail-safe clock monitor is enabled 0 = fail-safe clock monitor is disabled bit 12 ieso: internal external switchover bit 1 = internal/external switchover mode is enabled 0 = internal/external switchover mode is disabled bit 11 clkouten : clock out enable bit 1 = clkout function is disabled. i/o or oscillator function on ra6/clkout 0 = clkout function is enabled on ra6/clkout bit 10-9 boren<1:0>: brown-out reset enable bits (1) 11 = bor enabled 10 = bor enabled during operation and disabled in sleep 01 = bor controlled by sboren bit of the borcon register 00 = bor disabled bit 8 cpd : data code protection bit (2) 1 = data memory code protection is disabled 0 = data memory code protection is enabled bit 7 cp : code protection bit (3) 1 = program memory code protection is disabled 0 = program memory code protection is enabled bit 6 mclre: re3/mclr /v pp pin function select bit if lvp bit = 1 : this bit is ignored. if lvp bit = 0 : 1 =re3/mclr /v pp pin function is mclr ; weak pull-up enabled. 0 = re3/mclr /v pp pin function is digital input; mclr internally disabled; weak pull-up under control of wpue3 bit. bit 5 pwrte : power-up timer enable bit (1) 1 = pwrt disabled 0 = pwrt enabled bit 4-3 wdte<1:0>: watchdog timer enable bit 11 = wdt enabled 10 = wdt enabled while running and disabled in sleep 01 = wdt controlled by the swdten bit in the wdtcon register 00 = wdt disabled note 1: enabling brown-out reset does not automatically enable power-up timer. 2: the entire data eeprom will be erased when the c ode protection is tur ned off during an erase. 3: the entire program memory will be erased when the code protection is turned off.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 57 pic16(l)f1946/1947 bit 2-0 fosc<2:0>: oscillator selection bits 111 = ech: external clock, high-power mode: clkin on ra7/osc1/clkin 110 = ecm: external clock, medium-power mode: clkin on ra7/osc1/clkin 101 = ecl: external clock, low-power mode: clkin on ra7/osc1/clkin 100 = intosc oscillator: i/o function on ra7/osc1/clkin 011 = extrc oscillator: rc function on ra7/osc1/clkin 010 = hs oscillator: high-speed crystal/resonator on ra6/osc2/clkout pin and ra7/osc1/clkin 001 = xt oscillator: crystal/resonator on ra6/osc2/clkout pin and ra7/osc1/clkin 000 = lp oscillator: low-power crystal on ra6/osc2/clkout pin and ra7/osc1/clkin register 4-1: configurat ion word 1 (continued) note 1: enabling brown-out reset does not automatically enable power-up timer. 2: the entire data eeprom will be erased when the c ode protection is tur ned off during an erase. 3: the entire program memory will be erased when the code protection is turned off.
pic16(l)f1946/1947 ds41414c-page 58 preliminary ? 2010-2011 microchip technology inc. register 4-2: co nfiguration word 2 r/p-1/1 r/p-1/1 u-1 r/p-1/1 r/p-1/1 r/p-1/1 u-1 lvp debug (2) ? borv stvren pllen ? bit 13 bit 7 u-1 u-1 r/p-1/1 u-1 u-1 r/p-1/1 r/p-1/1 ? ?vcapen ? ?wrt1wrt0 bit 6 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = va lue at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared p = programmable bit bit 13 lvp: low-voltage programming enable bit (1) 1 = low-voltage programming enabled 0 = high-voltage on mclr /v pp must be used for programming bit 12 debug : in-circuit debugger mode bit 1 = in-circuit debugger disabled, rb6/icspclk and rb7/icspdat are general purpose i/o pins 0 = in-circuit debugger enabled, rb6/icspclk and rb7/icspdat are dedicated to the debugger bit 11 unimplemented: read as ? 1 ? bit 10 borv: brown-out reset voltage selection bit 1 = brown-out reset voltage set to 1.9v 0 = brown-out reset voltage set to 2.5v bit 9 stvren: stack overflow/underflow reset enable bit 1 = stack overflow or underflow will cause a reset 0 = stack overflow or underflow will not cause a reset bit 8 pllen: pll enable bit 1 = 4xpll enabled 0 = 4xpll disabled bit 7-5 unimplemented: read as ? 1 ? bit 4 vcapen>: voltage regulator capacitor enable bits 0 =v cap functionality is enabled on rf0 1 = no capacitor on v cap pin bit 2-3 unimplemented: read as ? 1 ? bit 1-0 wrt<1:0>: flash memory self-write protection bits 8 kw flash memory (pic16f/lf1946 only) : 11 = write protection off 10 = 000h to 1ffh write-protected, 200h to 1fffh may be modified by eecon control 01 = 000h to fffh write-protected, 1000h to 1fffh may be modified by eecon control 00 = 000h to 1fffh write-protected, no addresses may be modified by eecon control 16 kw flash memory (pic16f/lf1947) : 11 = write protection off 10 = 000h to 1ffh write-protected, 200h to 3fffh may be modified by eecon control 01 = 000h to 1fffh write-protected, 2000h to 3fffh may be modified by eecon control 00 = 000h to 3fffh write-protected, no addresses may be modified by eecon control note 1: the lvp bit cannot be programmed to ? 0 ? when programming mode is entered via lvp. 2: the debug bit in configuration word is managed automatica lly by device development tools including debuggers and programmers. for normal device operation, this bit should be maintained as a ' 1 '.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 59 pic16(l)f1946/1947 4.3 code protection code protection allows the device to be protected from unauthorized access. program memory protection and data eeprom protection are controlled independently. internal access to the program memory and data eeprom are unaffected by any code protection setting. 4.3.1 program memory protection the entire program memory space is protected from external reads and writes by the cp bit in configuration word 1. when cp = 0 , external reads and writes of program memory are inhibited and a read will return all ? 0 ?s. the cpu can continue to read program memory, regardless of the protection bit settings. writing the program memory is dependent upon the write protection setting. see section 4.4 ?write protection? for more information. 4.3.2 data eeprom protection the entire data eeprom is protected from external reads and writes by the cpd bit. when cpd = 0 , external reads and writes of data eeprom are inhibited. the cpu can continue to read and write data eeprom regardless of the protection bit settings. 4.4 write protection write protection allows the device to be protected from unintended self-writes. applications, such as bootloader software, can be protected while allowing other regions of the program memory to be modified. the wrt<1:0> bits in configuration word 2 define the size of the program memory block that is protected. 4.5 user id four memory locations (8000h-8003h) are designated as id locations where the user can store checksum or other code identification numbers. these locations are readable and writable during normal execution. see section 4.6 ?device id and revision id? for more information on accessing these memory locations. for more information on checksum calculation, see the ? pic16f193x/lf193x/pic16f194x/lf194x memory programming specification ? (ds41397).
pic16(l)f1946/1947 ds41414c-page 60 preliminary ? 2010-2011 microchip technology inc. 4.6 device id and revision id the memory location 8006h is where the device id and revision id are stored. the upper nine bits hold the device id. the lower five bits hold the revision id. see section 11.5 ?user id, device id and configuration word access? for more information on accessing these memory locations. development tools, such as device programmers and debuggers, may be used to read the device id and revision id. register 4-3: deviceid: device id register (1) rrrrrrr dev8 dev7 dev6 dev5 dev4 dev3 dev2 bit 13 bit 7 rrrrrrr dev1 dev0 rev4 rev3 rev2 rev1 rev0 bit 6 bit 0 legend: u = unimplemented bit, read as ?0? r = readable bit w = writable bit ?0? = bit is cleared -n = value at por ?1? = bit is set x = bit is unknown bit 13-5 dev<8:0>: device id bits 100011001 = pic16f1946 100011010 = pic16f1947 100011011 = pic16lf1946 100011100 = pic16lf1947 bit 4-0 rev<4:0>: revision id bits these bits are used to identify the revision. note 1: this location cannot be written.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 61 pic16(l)f1946/1947 5.0 oscillator module (with fail-safe clock monitor) 5.1 overview the oscillator module has a wide variety of clock sources and selection features that allow it to be used in a wide range of applications while maximizing perfor- mance and minimizing power consumption. figure 5-1 illustrates a block diagram of the oscillator module. clock sources can be supplied from external oscillators, quartz crystal resonators, ceramic resonators and resistor-capacitor (rc) circuits. in addition, the system clock source can be supplied from one of two internal oscillators and pll circuits, with a choice of speeds selectable via software. additional clock features include: ? selectable system clock source between external or internal sources via software. ? two-speed start-up mode, which minimizes latency between external oscillator start-up and code execution. ? fail-safe clock monitor (fscm) designed to detect a failure of the external clock source (lp, xt, hs, ec or rc modes) and switch automatically to the internal oscillator. ? oscillator start-up timer (ost) ensures stability of crystal oscillator sources the oscillator module can be configured in one of eight clock modes. 1. ecl ? external clock low power mode (0 mhz to 0.5 mhz) 2. ecm ? external clock medium power mode (0.5 mhz to 4 mhz) 3. ech ? external clock high power mode (4 mhz to 32 mhz) 4. lp ? 32 khz low-power crystal mode. 5. xt ? medium gain crystal or ceramic resonator oscillator mode (up to 4 mhz) 6. hs ? high gain crystal or ceramic resonator mode (4 mhz to 20 mhz) 7. rc ? external resistor-capacitor (rc). 8. intosc ? internal oscillator (31 khz to 32 mhz). clock source modes are selected by the fosc<2:0> bits in the configuration word 1. the fosc bits determine the type of oscillator that will be used when the device is first powered. the ec clock mode relies on an external logic level signal as the device clock source. the lp, xt, and hs clock modes require an external crystal or resonator to be connected to the device. each mode is optimized for a different frequency range. the rc clock mode requires an external resistor and capacitor to set the oscillator frequency. the intosc internal oscillator block produces low, medium, and high frequency clock sources, designated lfintosc, mfintosc, and hfintosc. (see internal oscillator block, figure 5-1 ). a wide selection of device clock frequencies may be derived from these three clock sources.
pic16(l)f1946/1947 ds41414c-page 62 preliminary ? 2010-2011 microchip technology inc. figure 5-1: simplified pic ? mcu clock source block diagram 4 x pll fosc<2:0> oscillator t1oscen enable oscillator t1oso t1osi clock source option for other modules osc1 osc2 sleep lp, xt, hs, rc, ec t1osc cpu and postscaler mux mux 16 mhz 8 mhz 4 mhz 2 mhz 1 mhz 250 khz 500 khz ircf<3:0> 31 khz 500 khz source internal oscillator block wdt, pwrt, fail-safe clock monitor 16 mhz internal oscillator (hfintosc) clock control scs<1:0> hfpll 31 khz (lfintosc) two-speed start-up and other modules oscillator 31 khz source 500 khz (mfintosc) 125 khz 31.25 khz 62.5 khz fosc<2:0> = 100 peripherals sleep external timer1
? 2010-2011 microchip technology inc. preliminary ds41414c-page 63 pic16(l)f1946/1947 5.2 clock source types clock sources can be classified as external or internal. external clock sources rely on external circuitry for the clock source to function. examples are: oscillator mod- ules (ec mode), quartz crystal resonators or ceramic resonators (lp, xt and hs modes) and resis- tor-capacitor (rc) mode circuits. internal clock sources are contained internally within the oscillator module. the internal oscillator block has two internal oscillators and a dedicated phase-locked-loop (hfpll) that are used to generate three internal system clock sources: the 16 mhz high-frequency internal oscillator (hfintosc), 500 khz (mfintosc) and the 31 khz low-frequency internal oscillator (lfintosc). the system clock can be selected between external or internal clock sources via the system clock select (scs) bits in the osccon register. see section 5.3 ?clock switching? for additional information. 5.2.1 external clock sources an external clock source can be used as the device system clock by performing one of the following actions: ? program the fosc<2:0> bits in the configuration word 1 to select an external clock source that will be used as the default system clock upon a device reset. ? write the scs<1:0> bits in the osccon register to switch the system clock source to: - timer1 oscillator during run-time, or - an external clock source determined by the value of the fosc bits. see section 5.3 ?clock switching? for more informa- tion. 5.2.1.1 ec mode the external clock (ec) mode allows an externally generated logic level signal to be the system clock source. when operating in this mode, an external clock source is connected to the osc1 input. osc2/clkout is available for general purpose i/o or clkout. figure 5-2 shows the pin connections for ec mode. ec mode has 3 power modes to select from through configuration word 1: ? high-power, 4-32 mhz (fosc = 111 ) ? medium power, 0.5-4 mhz (fosc = 110 ) ? low-power, 0-0.5 mhz (fosc = 101 ) the oscillator start-up timer (ost) is disabled when ec mode is selected. therefore, there is no delay in operation after a power-on reset (por) or wake-up from sleep. because the pic ? mcu design is fully static, stopping the external clock input will have the effect of halting the device while leaving all data intact. upon restarting the external clock, the device will resume operation as if no time had elapsed. figure 5-2: external clock (ec) mode operation 5.2.1.2 lp, xt, hs modes the lp, xt and hs modes support the use of quartz crystal resonators or ceramic resonators connected to osc1 and osc2 ( figure 5-3 ). the three modes select a low, medium or high gain setting of the internal inverter-amplifier to support various resonator types and speed. lp oscillator mode selects the lowest gain setting of the internal inverter-amplifier. lp mode current consumption is the least of the three modes. this mode is designed to drive only 32.768 khz tuning-fork type crystals (watch crystals). xt oscillator mode selects the intermediate gain setting of the internal inverter-amplifier. xt mode current consumption is the medium of the three modes. this mode is best suited to drive resonators with a medium drive level specification. hs oscillator mode selects the highest gain setting of the internal inverter-amplifier. hs mode current consumption is the highest of the three modes. this mode is best suited for resonators that require a high drive setting. figure 5-3 and figure 5-4 show typical circuits for quartz crystal and ceramic resonators, respectively. osc1/clkin osc2/clkout clock from ext. system pic ? mcu f osc /4 or i/o (1) note 1: output depends upon clkouten bit of the configuration word 1.
pic16(l)f1946/1947 ds41414c-page 64 preliminary ? 2010-2011 microchip technology inc. figure 5-3: quartz crystal operation (lp, xt or hs mode) figure 5-4: ceramic resonator operation (xt or hs mode) 5.2.1.3 oscillator start-up timer (ost) if the oscillator module is configured for lp, xt or hs modes, the oscillator start-up timer (ost) counts 1024 oscillations from osc1. this occurs following a power-on reset (por) and when the power-up timer (pwrt) has expired (if configured), or a wake-up from sleep. during this time, the program counter does not increment and program execution is suspended. the ost ensures that the oscillator circuit, using a quartz crystal resonator or ceramic resonator, has started and is providing a stable system clock to the oscillator module. in order to minimize latency between external oscillator start-up and code execution, the two-speed clock start-up mode can be selected (see section 5.4 ?two-speed clock start-up mode? ). 5.2.1.4 4x pll the oscillator module contains a 4x pll that can be used with both external and internal clock sources to provide a system clock source. the input frequency for the 4x pll must fall within specifications. see the pll clock timing specifications in section 30.0 ?electrical specifications? . the 4x pll may be enabled for use by one of two methods: 1. program the pllen bit in configuration word 2 to a ? 1 ?. 2. write the spllen bit in the osccon register to a ? 1 ?. if the pllen bit in configuration word 2 is programmed to a ? 1 ?, then the value of spllen is ignored. note 1: quartz crystal characteristics vary according to type, package and manufacturer. the user should consult the manufacturer data sheets for specifications and recommended application. 2: always verify oscillator performance over the v dd and temperature range that is expected for the application. 3: for oscillator design assistance, reference the following microchip applications notes: ? an826, ? crystal oscillator basics and crystal selection for rfpic ? and pic ? devices ? (ds00826) ? an849, ? basic pic ? oscillator design ? (ds00849) ? an943, ? practical pic ? oscillator analysis and design ? (ds00943) ? an949, ? making your oscillator work ? (ds00949) note 1: a series resistor (r s ) may be required for quartz crystals with low drive level. 2: the value of r f varies with the oscillator mode selected (typically between 2 m ? to 10 m ?? . c1 c2 quartz r s (1) osc1/clkin r f (2) sleep to internal logic pic ? mcu crystal osc2/clkout note 1: a series resistor (r s ) may be required for ceramic resonators with low drive level. 2: the value of r f varies with the oscillator mode selected (typically between 2 m ? to 10 m ?? . 3: an additional parallel feedback resistor (r p ) may be required for proper ceramic resonator operation. c1 c2 ceramic r s (1) osc1/clkin r f (2) sleep to internal logic pic ? mcu r p (3) resonator osc2/clkout
? 2010-2011 microchip technology inc. preliminary ds41414c-page 65 pic16(l)f1946/1947 5.2.1.5 timer1 oscillator the timer1 oscillator is a separate crystal oscillator that is associated with the timer1 peripheral. it is opti- mized for timekeeping operations with a 32.768 khz crystal connected between the t1oso and t1osi device pins. the timer1 oscillator can be used as an alternate sys- tem clock source and can be selected during run-time using clock switching. refer to section 5.3 ?clock switching? for more information. figure 5-5: quartz crystal operation (timer1 oscillator) 5.2.1.6 external rc mode the external resistor-capacitor (rc) modes support the use of an external rc circuit. this allows the designer maximum flexibility in frequency choice while keeping costs to a minimum when clock accuracy is not required. the rc circuit connects to osc1. osc2/clkout is available for general purpose i/o or clkout. the function of the osc2/clkout pin is determined by the state of the clkouten bit in configuration word 1. figure 5-6 shows the external rc mode connections. figure 5-6: external rc modes the rc oscillator frequency is a function of the supply voltage, the resistor (r ext ) and capacitor (c ext ) values and the operating temperature. other factors affecting the oscillator frequency are: ? threshold voltage variation ? component tolerances ? packaging variations in capacitance the user also needs to take into account variation due to tolerance of external rc components used. note 1: quartz crystal characteristics vary according to type, package and manufacturer. the user should consult the manufacturer data sheets for specifications and recommended application. 2: always verify oscillator performance over the v dd and temperature range that is expected for the application. 3: for oscillator design assistance, reference the following microchip applications notes: ? an826, ? crystal oscillator basics and crystal selection for rfpic ? and pic ? devices ? (ds00826) ? an849, ? basic pic ? oscillator design ? (ds00849) ? an943, ? practical pic ? oscillator analysis and design ? (ds00943) ? an949, ? making your oscillator work ? (ds00949) ? tb097, ? interfacing a micro crystal ms1v-t1k 32.768 khz tuning fork crystal to a pic16f690/ss ? (ds91097) ? an1288, ? design practices for low-power external oscillators ? (ds01288) c1 c2 32.768 khz t1osi to internal logic pic ? mcu crystal t1oso quartz osc2/clkout c ext r ext pic ? mcu osc1/clkin f osc /4 or internal clock v dd v ss recommended values: 10 k ? ? r ext ? 100 k ? , <3v 3 k ? ? r ext ? 100 k ? , 3-5v c ext > 20 pf, 2-5v note 1: output depends upon clkouten bit of the configuration word 1. i/o (1)
pic16(l)f1946/1947 ds41414c-page 66 preliminary ? 2010-2011 microchip technology inc. 5.2.2 internal clock sources the device may be configured to use the internal oscil- lator block as the system clock by performing one of the following actions: ? program the fosc<2:0> bits in configuration word 1 to select the intosc clock source, which will be used as the default system clock upon a device reset. ? write the scs<1:0> bits in the osccon register to switch the system clock source to the internal oscillator during run-time. see section 5.3 ?clock switching? for more information. in intosc mode, osc1/clkin is available for general purpose i/o. osc2/clkout is available for general purpose i/o or clkout. the function of the osc2/clkout pin is determined by the state of the clkouten bit in configuration word 1. the internal oscillator block has two independent oscillators and a dedicated phase-locked loop, hfpll that can produce one of three internal system clock sources. 1. the hfintosc (high-frequency internal oscillator) is factory calibrated and operates at 16 mhz. the hfintosc source is generated from the 500 khz mfintosc source and the dedicated phase-locked loop, hfpll. the frequency of the hfintosc can be user-adjusted via software using the osctune register ( register 5-3 ). 2. the mfintosc (medium-frequency internal oscillator) is factory calibrated and operates at 500 khz. the frequency of the mfintosc can be user-adjusted via software using the osctune register ( register 5-3 ). 3. the lfintosc (low-frequency internal oscillator) is uncalibrated and operates at 31 khz. 5.2.2.1 hfintosc the high-frequency internal oscillator (hfintosc) is a factory calibrated 16 mhz internal clock source. the frequency of the hfintosc can be altered via software using the osctune register ( register 5-3 ). the output of the hfintosc connects to a postscaler and multiplexer (see figure 5-1 ). one of nine frequencies derived from the hfintosc can be selected via software using the ircf<3:0> bits of the osccon register. see section 5.2.2.7 ?internal oscillator clock switch timing? for more information. the hfintosc is enabled by: ? configure the ircf<3:0> bits of the osccon register for the desired hf frequency, and ?fosc<2:0> = 100 , or ? set the system clock source (scs) bits of the osccon register to ? 1x ?. the high frequency internal oscillator ready bit (hfiofr) of the oscstat register indicates when the hfintosc is running and can be utilized. the high frequency internal oscillator status locked bit (hfiofl) of the oscstat register indicates when the hfintosc is running within 2% of its final value. the high frequency internal oscillator status stable bit (hfiofs) of the oscstat register indicates when the hfintosc is running within 0.5% of its final value. 5.2.2.2 mfintosc the medium-frequency internal oscillator (mfintosc) is a factory calibrated 500 khz internal clock source. the frequency of the mfintosc can be altered via software using the osctune register ( register 5-3 ). the output of the mfintosc connects to a postscaler and multiplexer (see figure 5-1 ). one of nine frequencies derived from the mfintosc can be selected via software using the ircf<3:0> bits of the osccon register. see section 5.2.2.7 ?internal oscillator clock switch timing? for more information. the mfintosc is enabled by: ? configure the ircf<3:0> bits of the osccon register for the desired hf frequency, and ?fosc<2:0> = 100 , or ? set the system clock source (scs) bits of the osccon register to ? 1x ? the medium frequency internal oscillator ready bit (mfiofr) of the oscstat register indicates when the mfintosc is running and can be utilized.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 67 pic16(l)f1946/1947 5.2.2.3 internal oscillator frequency adjustment the 500 khz internal oscillator is factory calibrated. this internal oscillator can be adjusted in software by writing to the osctune register ( register 5-3 ). since the hfintosc and mfintosc clock sources are derived from the 500 khz internal oscillator a change in the osctune register value will apply to both. the default value of the osctune register is ? 0 ?. the value is a 6-bit two?s complement number. a value of 1fh will provide an adjustment to the maximum frequency. a value of 20h will provide an adjustment to the minimum frequency. when the osctune register is modified, the oscillator frequency will begin shifting to the new frequency. code execution continues during this shift. there is no indication that the shift has occurred. osctune does not affect the lfintosc frequency. operation of features that depend on the lfintosc clock source frequency, such as the power-up timer (pwrt), watchdog timer (wdt), fail-safe clock monitor (fscm) and peripherals, are not affected by the change in frequency. 5.2.2.4 lfintosc the low-frequency internal oscillator (lfintosc) is an uncalibrated 31 khz internal clock source. the output of the lfintosc connects to a postscaler and multiplexer (see figure 5-1 ). select 31 khz, via software, using the ircf<3:0> bits of the osccon register. see section 5.2.2.7 ?internal oscillator clock switch timing? for more information. the lfintosc is also the frequency for the power-up timer (pwrt), watchdog timer (wdt) and fail-safe clock monitor (fscm). the lfintosc is enabled by selecting 31 khz (ircf<3:0> bits of the osccon register = 000) as the system clock source (scs bits of the osccon register = 1x ), or when any of the following are enabled: ? configure the ircf<3:0> bits of the osccon register for the desired lf frequency, and ?fosc<2:0> = 100 , or ? set the system clock source (scs) bits of the osccon register to ? 1x ? peripherals that use the lfintosc are: ? power-up timer (pwrt) ? watchdog timer (wdt) ? fail-safe clock monitor (fscm) the low frequency internal oscillator ready bit (lfiofr) of the oscstat register indicates when the lfintosc is running and can be utilized. 5.2.2.5 internal oscillator frequency selection the system clock speed can be selected via software using the internal oscillator frequency select bits ircf<3:0> of the osccon register. the output of the 16 mhz hfintosc and 31 khz lfintosc connects to a postscaler and multiplexer (see figure 5-1 ). the internal oscillator frequency select bits ircf<3:0> of the osccon register select the frequency output of the internal oscillators. one of the following frequencies can be selected via software: ? 32 mhz (requires 4x pll) ?16 mhz ?8 mhz ?4 mhz ?2 mhz ?1 mhz ? 500 khz (default after reset) ?250 khz ?125 khz ?62.5 khz ?31.25 khz ? 31 khz (lfintosc) the ircf<3:0> bits of the osccon register allow duplicate selections for some frequencies. these dupli- cate choices can offer system design trade-offs. lower power consumption can be obtained when changing oscillator sources for a given frequency. faster transi- tion times can be obtained between frequency changes that use the same oscillator source. note: following any reset, the ircf<3:0> bits of the osccon register are set to ? 0111 ? and the frequency selection is set to 500 khz. the user can modify the ircf bits to select a different frequency.
pic16(l)f1946/1947 ds41414c-page 68 preliminary ? 2010-2011 microchip technology inc. 5.2.2.6 32 mhz internal oscillator frequency selection the internal oscillator block can be used with the 4x pll associated with the external oscillator block to produce a 32 mhz internal system clock source. the following settings are required to use the 32 mhz inter- nal clock source: ? the fosc bits in configuration word 1 must be set to use the intosc source as the device sys- tem clock (fosc<2:0> = 100 ). ? the scs bits in the osccon register must be cleared to use the clock determined by fosc<2:0> in configuration word 1 (scs<1:0> = 00 ). ? the ircf bits in the osccon register must be set to the 8 mhz hfintosc set to use (ircf<3:0> = 1110 ). ? the spllen bit in the osccon register must be set to enable the 4xpll, or the pllen bit of the configuration word 2 must be programmed to a ? 1 ?. the 4xpll is not available for use with the internal oscillator when the scs bits of the osccon register are set to ? 1x ?. the scs bits must be set to ? 00 ? to use the 4xpll with the internal oscillator. 5.2.2.7 internal oscillator clock switch timing when switching between the hfintosc, mfintosc and the lfintosc, the new oscillator may already be shut down to save power (see figure 5-7 ). if this is the case, there is a delay after the ircf<3:0> bits of the osccon register are modified before the frequency selection takes place. the oscstat register will reflect the current active status of the hfintosc, mfintosc and lfintosc oscillators. the sequence of a frequency selection is as follows: 1. ircf<3:0> bits of the osccon register are modified. 2. if the new clock is shut down, a clock start-up delay is started. 3. clock switch circuitry waits for a falling edge of the current clock. 4. the current clock is held low and the clock switch circuitry waits for a rising edge in the new clock. 5. the new clock is now active. 6. the oscstat register is updated as required. 7. clock switch is complete. see figure 5-7 for more details. if the internal oscillator speed is switched between two clocks of the same source, there is no start-up delay before the new frequency is selected. clock switching time delays are shown in table 5-1 . start-up delay specifications are located in the oscillator tables of section 30.0 ?electrical specifications? note: when using the pllen bit of the configuration word 2, the 4xpll cannot be disabled by software and the 8 mhz hfintosc option will no longer be available.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 69 pic16(l)f1946/1947 figure 5-7: internal oscillator switch timing hfintosc/ lfintosc ircf <3:0> system clock hfintosc/ lfintosc ircf <3:0> system clock ?? 0 ?? 0 ?? 0 ?? 0 start-up time 2-cycle sync running 2-cycle sync running hfintosc/ lfintosc (fscm and wdt disabled) hfintosc/ lfintosc (either fscm or wdt enabled) lfintosc hfintosc/ ircf <3:0> system clock = 0 ? 0 start-up time 2-cycle sync running lfintosc hfintosc/mfintosc lfintosc turns off unless wdt or fscm is enabled mfintosc mfintosc mfintosc mfintosc mfintosc
pic16(l)f1946/1947 ds41414c-page 70 preliminary ? 2010-2011 microchip technology inc. 5.3 clock switching the system clock source can be switched between external and internal clock sources via software using the system clock select (scs) bits of the osccon register. the following clock sources can be selected using the scs bits: ? default system oscillator determined by fosc bits in configuration word 1 ? timer1 32 khz crystal oscillator ? internal oscillator block (intosc) 5.3.1 system clock select (scs) bits the system clock select (scs) bits of the osccon register selects the system clock source that is used for the cpu and peripherals. ? when the scs bits of the osccon register = 00 , the system clock source is determined by value of the fosc<2:0> bits in the configuration word 1. ? when the scs bits of the osccon register = 01 , the system clock source is the timer1 oscillator. ? when the scs bits of the osccon register = 1x , the system clock source is chosen by the internal oscillator frequency selected by the ircf<3:0> bits of the osccon register. after a reset, the scs bits of the osccon register are always cleared. when switching between clock sources, a delay is required to allow the new clock to stabilize. these oscil- lator delays are shown in table 5-1 . 5.3.2 oscillator start-up time-out status (osts) bit the oscillator start-up time-out status (osts) bit of the oscstat register indicates whether the system clock is running from the external clock source, as defined by the fosc<2:0> bits in the configuration word 1, or from the internal clock source. in particular, osts indicates that the oscillator start-up timer (ost) has timed out for lp, xt or hs modes. the ost does not reflect the status of the timer1 oscillator. 5.3.3 timer1 oscillator the timer1 oscillator is a separate crystal oscillator associated with the timer1 peripheral. it is optimized for timekeeping operations with a 32.768 khz crystal connected between the t1oso and t1osi device pins. the timer1 oscillator is enabled using the t1oscen control bit in the t1con register. see section 21.0 ?timer1 module with gate control? for more information about the timer1 peripheral. 5.3.4 timer1 oscillator ready (t1oscr) bit the user must ensure that the timer1 oscillator is ready to be used before it is selected as a system clock source. the timer1 oscillator ready (t1oscr) bit of the oscstat register indicates whether the timer1 oscillator is ready to be used. after the t1oscr bit is set, the scs bits can be configured to select the timer1 oscillator. note: any automatic clock switch, which may occur from two-speed start-up or fail-safe clock monitor, does not update the scs bits of the osccon register. the user can monitor the osts bit of the oscstat register to determine the current system clock source.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 71 pic16(l)f1946/1947 5.4 two-speed clock start-up mode two-speed start-up mode provides additional power savings by minimizing the latency between external oscillator start-up and code execution. in applications that make heavy use of the sleep mode, two-speed start-up will remove the external oscillator start-up time from the time spent awake and can reduce the overall power consumption of the device. this mode allows the application to wake-up from sleep, perform a few instructions using the intosc internal oscillator block as the clock source and go back to sleep without waiting for the external oscillator to become stable. two-speed start-up provides benefits when the oscil- lator module is configured for lp, xt, or hs modes. the oscillator start-up timer (ost) is enabled for these modes and must count 1024 oscillations before the oscillator can be used as the system clock source. if the oscillator module is configured for any mode other than lp, xt or hs mode, then two-speed start-up is disabled. this is because the external clock oscillator does not require any stabilization time after por or an exit from sleep. if the ost count reaches 1024 before the device enters sleep mode, the osts bit of the oscstat reg- ister is set and program execution switches to the external oscillator. however, the system may never operate from the external oscillator if the time spent awake is very short. 5.4.1 two-speed start-up mode configuration two-speed start-up mode is configured by the following settings: ? ieso (of the configuration word 1) = 1 ; inter- nal/external switchover bit (two-speed start-up mode enabled). ? scs (of the osccon register) = 00 . ? fosc<2:0> bits in the configuration word 1 configured for lp, xt or hs mode. two-speed start-up mode is entered after: ? power-on reset (por) and, if enabled, after power-up timer (pwrt) has expired, or ? wake-up from sleep. table 5-1: oscillator switching delays note: executing a sleep instruction will abort the oscillator start-up time and will cause the osts bit of the oscstat register to remain clear. switch from switch to frequency oscillator delay sleep/por lfintosc (1) mfintosc (1) hfintosc (1) 31 khz 31.25 khz-500 khz 31.25khz-16mhz oscillator warm-up delay (t warm ) sleep/por ec, rc (1) dc ? 32 mhz 2 cycles lfintosc ec, rc (1) dc ? 32 mhz 1 cycle of each sleep/por timer1 oscillator lp, xt, hs (1) 32 khz-20 mhz 1024 clock cycles (ost) any clock source mfintosc (1) hfintosc (1) 31.25 khz-500 khz 31.25khz-16mhz 2 ? s (approx.) any clock source lfintosc (1) 31 khz 1 cycle of each any clock source timer1 oscillator 32 khz 1024 clock cycles (ost) pll inactive pll active 16-32 mhz 2 ms (approx.) note 1: pll inactive.
pic16(l)f1946/1947 ds41414c-page 72 preliminary ? 2010-2011 microchip technology inc. 5.4.2 two-speed start-up sequence 1. wake-up from power-on reset or sleep. 2. instructions begin execution by the internal oscillator at the frequency set in the ircf<3:0> bits of the osccon register. 3. ost enabled to count 1024 clock cycles. 4. ost timed out, wait for falling edge of the internal oscillator. 5. osts is set. 6. system clock held low until the next falling edge of new clock (lp, xt or hs mode). 7. system clock is switched to external clock source. 5.4.3 checking two-speed clock status checking the state of the osts bit of the oscstat register will confirm if the microcontroller is running from the external clock source, as defined by the fosc<2:0> bits in the configuration word 1, or the internal oscillator. figure 5-8: two-speed start-up 0 1 1022 1023 pc + 1 t ost t intosc osc1 osc2 program counter system clock pc - n pc
? 2010-2011 microchip technology inc. preliminary ds41414c-page 73 pic16(l)f1946/1947 5.5 fail-safe clock monitor the fail-safe clock monitor (fscm) allows the device to continue operating should the external oscillator fail. the fscm can detect oscillator failure any time after the oscillator start-up timer (ost) has expired. the fscm is enabled by setting the fcmen bit in the configuration word 1. the fscm is applicable to all external oscillator modes (lp, xt, hs, ec, timer1 oscillator and rc). figure 5-9: fscm block diagram 5.5.1 fail-safe detection the fscm module detects a failed oscillator by comparing the external oscillator to the fscm sample clock. the sample clock is generated by dividing the lfintosc by 64. see figure 5-9 . inside the fail detector block is a latch. the external clock sets the latch on each falling edge of the external clock. the sample clock clears the latch on each rising edge of the sample clock. a failure is detected when an entire half-cycle of the sample clock elapses before the external clock goes low. 5.5.2 fail-safe operation when the external clock fails, the fscm switches the device clock to an internal clock source and sets the bit flag osfif of the pir2 register. setting this flag will generate an interrupt if the osfie bit of the pie2 register is also set. the device firmware can then take steps to mitigate the problems that may arise from a failed clock. the system clock will continue to be sourced from the internal clock source until the device firmware successfully restarts the external oscillator and switches back to external operation. the internal clock source chosen by the fscm is determined by the ircf<3:0> bits of the osccon register. this allows the internal oscillator to be configured before a failure occurs. 5.5.3 fail-safe condition clearing the fail-safe condition is cleared after a reset, executing a sleep instruction or changing the scs bits of the osccon register. when the scs bits are changed, the ost is restarted. while the ost is running, the device continues to operate from the intosc selected in osccon. when the ost times out, the fail-safe condition is cleared and the device will be operating from the external clock source. the fail-safe condition must be cleared before the osfif flag can be cleared. 5.5.4 reset or wake-up from sleep the fscm is designed to detect an oscillator failure after the oscillator start-up timer (ost) has expired. the ost is used after waking up from sleep and after any type of reset. the ost is not used with the ec or rc clock modes so that the fscm will be active as soon as the reset or wake-up has completed. when the fscm is enabled, the two-speed start-up is also enabled. therefore, the device will always be executing code while the ost is operating. external lfintosc 64 s r q 31 khz (~32 ? s) 488 hz (~2 ms) clock monitor latch clock failure detected oscillator clock q sample clock note: due to the wide range of oscillator start-up times, the fail-safe circuit is not active during oscillator start-up (i.e., after exiting reset or sleep). after an appropriate amount of time, the user should check the status bits in the oscstat register to verify the oscillator start-up and that the system clock switchover has successfully completed.
pic16(l)f1946/1947 ds41414c-page 74 preliminary ? 2010-2011 microchip technology inc. figure 5-10: fscm timing diagram oscfif system clock output sample clock failure detected oscillator failure note: the system clock is normally at a much higher frequency than the sample clock. the relative frequencies in this example have been chosen for clarity. (q) te s t test test clock monitor output
? 2010-2011 microchip technology inc. preliminary ds41414c-page 75 pic16(l)f1946/1947 5.6 oscillator control registers register 5-1: osccon: os cillator control register r/w-0/0 r/w-0/0 r/w-1/1 r/w-1/1 r/w-1/1 u-0 r/w-0/0 r/w-0/0 spllen ircf<3:0> ? scs<1:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 spllen: software pll enable bit if pllen in configuration word 1 = 1 : spllen bit is ignored. 4x pll is always enabled (subject to oscillator requirements) if pllen in configuration word 1 = 0 : 1 = 4x pll is enabled 0 = 4x pll is disabled bit 6-3 ircf<3:0>: internal oscillator frequency select bits 000x =31khz lf 0010 =31.25khz mf 0011 =31.25khz hf (1) 0100 =62.5khz mf 0101 =125khz mf 0110 =250khz mf 0111 = 500 khz mf (default upon reset) 1000 =125khz hf (1) 1001 =250khz hf (1) 1010 =500khz hf (1) 1011 =1mhz hf 1100 =2mhz hf 1101 =4mhz hf 1110 = 8 mhz or 32 mhz hf(see section 5.2.2.1 ?hfintosc? ) 1111 = 16 mhz hf bit 2 unimplemented: read as ? 0 ? bit 1-0 scs<1:0>: system clock select bits 1x = internal oscillator block 01 = timer1 oscillator 00 = clock determined by fosc<2:0> in configuration word 1. note 1: duplicate frequency derived from hfintosc.
pic16(l)f1946/1947 ds41414c-page 76 preliminary ? 2010-2011 microchip technology inc. register 5-2: oscstat: oscillator status register r-1/q r-0/q r-q/q r-0/q r-0/q r-q/q r-0/0 r-0/q t1oscr pllr osts hfiofr hfiofl mfiofr lfiofr hfiofs bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared q = conditional bit 7 t1oscr: timer1 oscillator ready bit if t1oscen = 1 : 1 = timer1 oscillator is ready 0 = timer1 oscillator is not ready if t1oscen = 0 : 1 = timer1 clock source is always ready bit 6 pllr 4x pll ready bit 1 = 4x pll is ready 0 = 4x pll is not ready bit 5 osts: oscillator start-up time-out status bit 1 = running from the clock defined by the fosc<2:0> bits of the configuration word 1 0 = running from an internal oscillator bit 4 hfiofr: high frequency internal oscillator ready bit 1 = hfintosc is ready 0 = hfintosc is not ready bit 3 hfiofl: high frequency internal oscillator locked bit 1 = hfintosc is at least 2% accurate 0 = hfintosc is not 2% accurate bit 2 mfiofr: medium frequency internal oscillator ready bit 1 = mfintosc is ready 0 = mfintosc is not ready bit 1 lfiofr: low frequency internal oscillator ready bit 1 = lfintosc is ready 0 = lfintosc is not ready bit 0 hfiofs: high frequency internal oscillator stable bit 1 = hfintosc is at least 0.5% accurate 0 = hfintosc is not 0.5% accurate
? 2010-2011 microchip technology inc. preliminary ds41414c-page 77 pic16(l)f1946/1947 table 5-2: summary of registers asso ciated with clock sources table 5-3: summary of configura tion word with clock sources register 5-3: osctune: osci llator tuning register u-0 u-0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 ? ? tun<5:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-6 unimplemented: read as ? 0 ? bit 5-0 tun<4:0>: frequency tuning bits 011111 = maximum frequency 011110 = ? ? ? 000001 = 000000 = oscillator module is running at the factory-calibrated frequency. 111111 = ? ? ? 100000 = minimum frequency name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page osccon spllen ircf<3:0> ?scs<1:0>75 oscstat t1oscr pllr osts hfiofr hfiofl mfiofr lfiofr hfiofs 76 osctune ? ?tun<5:0>77 pie2 osfie c2ie c1ie eeie bclie lcdie c3ie ccp2ie (1) 95 pir2 osfif c2if c1if eeif bclif lcdif c3if ccp2if (1) 99 t1con tmr1cs<1:0> t1ckps<1:0> t1oscen t1sync ? tmr1on 205 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by clock sources. note 1: pic16f1947 only. name bits bit -/7 bit -/6 bit 13/5 bit 12/4 bit 11/3 bit 10/2 bit 9/1 bit 8/0 register on page config1 13:8 ? ? fcmen ieso clkouten boren<1:0> cpd 56 7:0 cp mclre pwrte wdte<1:0> fosc<2:0> config2 13:8 ? ? lvp debug ? borv stvren pllen 58 7:0 ? ? ?vcapen ? ? wrt<1:0> legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by clock sources. note 1: pic16f1946/47 only.
pic16(l)f1946/1947 ds41414c-page 78 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 79 pic16(l)f1946/1947 6.0 resets there are multiple ways to reset this device: ? power-on reset (por) ? brown-out reset (bor) ?mclr reset ?wdt reset ? reset instruction ? stack overflow ? stack underflow ? programming mode exit to a l l o w v dd to stabilize, an optional power-up timer can be enabled to extend the reset time after a bor or por event. a simplified block diagram of the on-chip reset circuit is shown in figure 6-1 . figure 6-1: simplified block di agram of on-chip reset circuit external reset mclr v dd wdt time-out power-on reset lfintosc pwrt 64 ms pwrten brown-out reset bor reset instruction stack pointer stack overflow/underflow reset sleep mclre enable device reset zero programming mode exit
pic16(l)f1946/1947 ds41414c-page 80 preliminary ? 2010-2011 microchip technology inc. 6.1 power-on reset (por) the por circuit holds the device in reset until v dd has reached an acceptable level for minimum operation. slow rising v dd , fast operating speeds or analog performance may require greater than minimum v dd . the pwrt, bor or mclr features can be used to extend the start-up period until all device operation conditions have been met. 6.1.1 power-up timer (pwrt) the power-up timer provides a nominal 64 ms time- out on por or brown-out reset. the device is held in reset as long as pwrt is active. the pwrt delay allows additional time for the v dd to rise to an acceptable level. the power-up timer is enabled by clearing the pwrte bit in configuration word 1. the power-up timer starts after the release of the por and bor. for additional information, refer to application note an607, ?power-up trouble shooting? (ds00607). 6.2 brown-out reset (bor) the bor circuit holds the device in reset when v dd reaches a selectable minimum level. between the por and bor, complete voltage range coverage for execution protection can be implemented. the brown-out reset module has four operating modes controlled by the boren<1:0> bits in configu- ration word 1. the four operating modes are: ? bor is always on ? bor is off when in sleep ? bor is controlled by software ? bor is always off refer to tab le 6 - 1 for more information. the brown-out reset voltage level is selectable by configuring the borv bit in configuration word 2. a v dd noise rejection filter prevents the bor from trig- gering on small events. if v dd falls below v bor for a duration greater than parameter t bordc , the device will reset. see figure 6-3 for more information. table 6-1: bor operating modes 6.2.1 bor is always on when the boren bits of configuration word 1 are set to ? 11 ?, the bor is always on. the device start-up will be delayed until the bor is ready and v dd is higher than the bor threshold. bor protection is active during sleep. the bor does not delay wake-up from sleep. 6.2.2 bor is off in sleep when the boren bits of configuration word 1 are set to ? 10 ?, the bor is on, except in sleep. the device start-up will be delayed until the bor is ready and v dd is higher than the bor threshold. bor protection is not active during sleep. the device wake-up will be delayed until the bor is ready. 6.2.3 bor controlled by software when the boren bits of configuration word 1 are set to ? 01 ?, the bor is controlled by the sboren bit of the borcon register. the device start-up is not delayed by the bor ready condition or the v dd level. bor protection begins as soon as the bor circuit is ready. the status of the bor circuit is reflected in the borrdy bit of the borcon register. bor protection is unchanged by sleep. boren config bits sboren device mode bor mode device operation upon release of por device operation upon wake-up from sleep bor_on ( 11 ) x x active waits for bor ready (1) bor_nsleep ( 10) x awake active waits for bor ready bor_nsleep ( 10 ) x sleep disabled bor_sboren ( 01 ) 1 x active begins immediately bor_sboren ( 01 ) 0 x disabled begins immediately bor_off ( 00 ) x x disabled begins immediately note 1: even though this case specifically waits for the bor, the bor is already operating, so there is no delay in start-up.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 81 pic16(l)f1946/1947 figure 6-2: brown-out ready figure 6-3: brown -out situations t borrdy sboren b orrdy bor protection active t pwrt (1) v bor v dd internal reset v bor v dd internal reset t pwrt (1) < t pwrt t pwrt (1) v bor v dd internal reset note 1: t pwrt delay only if pwrte bit is programmed to ? 0 ?. register 6-1: borco n: brown-out reset control register r/w-1/u u-0 u-0 u-0 u-0 u-0 u-0 r-q/u sboren ? ? ? ? ? ?borrdy bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared q = value depends on condition bit 7 sboren: software brown-out reset enable bit if boren <1:0> in configuration word 1 ? 01 : sboren is read/write, but has no effect on the bor. if boren <1:0> in configuration word 1 = 01 : 1 = bor enabled 0 = bor disabled bit 6-1 unimplemented: read as ? 0 ? bit 0 borrdy: brown-out reset circuit ready status bit 1 = the brown-out reset circuit is active 0 = the brown-out reset circuit is inactive
pic16(l)f1946/1947 ds41414c-page 82 preliminary ? 2010-2011 microchip technology inc. 6.3 mclr the mclr is an optional external input that can reset the device. the mclr function is controlled by the mclre bit of configuration word 1 and the lvp bit of configuration word 2 ( ta b l e 6 - 2 ). 6.3.1 mclr enabled when mclr is enabled and the pin is held low, the device is held in reset. the mclr pin is connected to v dd through an internal weak pull-up. the device has a noise filter in the mclr reset path. the filter will detect and ignore small pulses. 6.3.2 mclr disabled when mclr is disabled, the pin functions as a general purpose input and the internal weak pull-up is under software control. see section 12.6 ?porte registers? for more information. 6.4 watchdog timer (wdt) reset the watchdog timer generates a reset if the firmware does not issue a clrwdt instruction within the time-out period. the to and pd bits in the status register are changed to indicate the wdt reset. see section 10.0 ?watchdog timer? for more information. 6.5 reset instruction a reset instruction will cause a device reset. the ri bit in the pcon register will be set to ? 0 ?. see ta b l e 6 - 4 for default conditions after a reset instruction has occurred. 6.6 stack overflow/underflow reset the device can reset when the stack overflows or underflows. the stkovf or stkunf bits of the pcon register indicate the reset condition. these resets are enabled by setting the stvren bit in configuration word 2. see section 3.4.2 ?overflow/underflow reset? for more information. 6.7 programming mode exit upon exit of programming mode, the device will behave as if a por had just occurred. 6.8 power-up timer the power-up timer optionally delays device execution after a bor or por event. this timer is typically used to allow v dd to stabilize before allowing the device to start running. the power-up timer is controlled by the pwrte bit of configuration word 1. 6.9 start-up sequence upon the release of a por or bor, the following must occur before the device will begin executing: 1. power-up timer runs to completion (if enabled). 2. oscillator start-up timer runs to completion (if required for oscillator source). 3. mclr must be released (if enabled). the total time-out will vary based on oscillator configu- ration and power-up timer configuration. see section 5.0 ?oscillator module (with fail-safe clock monitor)? for more information. the power-up timer and oscillator start-up timer run independently of mclr reset. if mclr is kept low long enough, the power-up timer and oscillator start-up timer will expire. upon bringing mclr high, the device will begin execution immediately (see figure 6-4 ). this is useful for testing purposes or to synchronize more than one device operating in parallel. table 6-2: mclr configuration mclre lvp mclr 00 disabled 10 enabled x1 enabled note: a reset does not drive the mclr pin low.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 83 pic16(l)f1946/1947 figure 6-4: reset start-up sequence t ost t mclr t pwrt v dd internal por power up timer mclr internal reset oscillator modes oscillator start up timer oscillator f osc internal oscillator oscillator f osc external clock (ec) clkin f osc external crystal
pic16(l)f1946/1947 ds41414c-page 84 preliminary ? 2010-2011 microchip technology inc. 6.10 determining the cause of a reset upon any reset, multiple bits in the status and pcon register are updated to indicate the cause of the reset. ta b l e 6 - 3 and tab l e 6 - 4 show the reset conditions of these registers. table 6-3: reset status bits and their significance table 6-4: reset condition for special registers (2) stkovf stkunf rmclr ri por bor to pd condition 00110x11 power-on reset 00110x0x illegal, to is set on por 00110xx0 illegal, pd is set on por 0011u011 brown-out reset uuuuuu0u wdt reset uuuuuu00 wdt wake-up from sleep uuuuuu10 interrupt wake-up from sleep uu0uuuuu mclr reset during normal operation uu0uuu10 mclr reset during sleep u u u 0 u u u u reset instruction executed 1uuuuuuu stack overflow reset (stvren = 1 ) u1uuuuuu stack underflow reset (stvren = 1 ) condition program counter status register pcon register power-on reset 0000h ---1 1000 00-- 110x mclr reset during normal operation 0000h ---u uuuu uu-- 0uuu mclr reset during sleep 0000h ---1 0uuu uu-- 0uuu wdt reset 0000h ---0 uuuu uu-- uuuu wdt wake-up from sleep pc + 1 ---0 0uuu uu-- uuuu brown-out reset 0000h ---1 1uuu 00-- 11u0 interrupt wake-up from sleep pc + 1 (1) ---1 0uuu uu-- uuuu reset instruction executed 0000h ---u uuuu uu-- u0uu stack overflow reset (stvren = 1 ) 0000h ---u uuuu 1u-- uuuu stack underflow reset (stvren = 1 ) 0000h ---u uuuu u1-- uuuu legend: u = unchanged, x = unknown, - = unimplemented bit, reads as ? 0 ?. note 1: when the wake-up is due to an interrupt and global enable bit (gie) is set, the return address is pushed on the stack and pc is loaded with the interrupt vector (0004h) after execution of pc + 1. 2: if a status bit is not implemented, that bit will be read as ? 0 ?.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 85 pic16(l)f1946/1947 6.11 power control (pcon) register the power control (pcon) register contains flag bits to differentiate between a: ? power-on reset (por ) ? brown-out reset (bor ) ? reset instruction reset (ri ) ? stack overflow reset (stkovf) ? stack underflow reset (stkunf) ?mclr reset (rmclr ) the pcon register bits are shown in register 6-2 . register 6-2: pcon: power control register r/w/hs-0/q r/w/hs-0/q u-0 u-0 r/w/hc-1/q r/w/hc-1/q r/w/hc-q/u r/w/hc-q/u stkovf stkunf ? ? rmclr ri por bor bit 7 bit 0 legend: hc = bit is cleared by hardware hs = bit is set by hardware r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -m/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared q = value depends on condition bit 7 stkovf: stack overflow flag bit 1 = a stack overflow occurred 0 = a stack overflow has not occurred or set to ? 0 ? by firmware bit 6 stkunf: stack underflow flag bit 1 = a stack underflow occurred 0 = a stack underflow has not occurred or set to ? 0 ? by firmware bit 5-4 unimplemented: read as ? 0 ? bit 3 rmclr : mclr reset flag bit 1 = a mclr reset has not occurred or set to ? 1 ? by firmware 0 = a mclr reset has occurred (set to ? 0 ? in hardware when a mclr reset occurs) bit 2 ri : reset instruction flag bit 1 = a reset instruction has not been executed or set to ? 1 ? by firmware 0 = a reset instruction has been executed (set to ? 0 ? in hardware upon executing a reset instruction) bit 1 por : power-on reset status bit 1 = no power-on reset occurred 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 = no brown-out reset occurred 0 = a brown-out reset occurred (must be set in software after a power-on reset or brown-out reset occurs)
pic16(l)f1946/1947 ds41414c-page 86 preliminary ? 2010-2011 microchip technology inc. table 6-5: summary of registers associated with resets name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page borcon sboren ? ? ? ? ? ? borrdy 81 pcon stkovf stkunf ? ?rmclr ri por bor 85 status ? ? ?to pd z dc c25 wdtcon ? ? wdtps<4:0> swdten 109 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by resets. note 1: other (non power-up) resets include mclr reset and watchdog timer reset during normal operation.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 87 pic16(l)f1946/1947 7.0 interrupts the interrupt feature allows certain events to preempt normal program flow. firmware is used to determine the source of the interrupt and act accordingly. some interrupts can be configured to wake the mcu from sleep mode. this chapter contains the following information for interrupts: ? operation ? interrupt latency ? interrupts during sleep ?int pin ? automatic context saving many peripherals produce interrupts. refer to the corresponding chapters for details. a block diagram of the interrupt logic is shown in figure 7-1 and figure 7-2 . figure 7-1: interrupt logic tmr0if tmr0ie intf inte iocif iocie gie peie wake-up (if in sleep mode) interrupt to cpu from peripheral interrupt logic ( figure 7-2 )
pic16(l)f1946/1947 ds41414c-page 88 preliminary ? 2010-2011 microchip technology inc. figure 7-2: peripheral interrupt logic tmr1gif tmr1gie adif adie rcif rcie txif txie sspif sspie osfif osfie c2if c2ie c1if c1ie eeif eeie bclif bclie lcdif lcdie tmr1if tmr1ie tmr6if tmr6ie ? ? ? ? ? ? ccp1if ccp1ie ccp5if ccp5ie ? ? ? ? ? ? to interrupt logic ( figure 7-1 )
? 2010-2011 microchip technology inc. preliminary ds41414c-page 89 pic16(l)f1946/1947 7.1 operation interrupts are disabled upon any device reset. they are enabled by setting the following bits: ? gie bit of the intcon register ? interrupt enable bit(s) for the specific interrupt event(s) ? peie bit of the intcon register (if the interrupt enable bit of the interrupt event is contained in the pie1, pie2, pie3 and pie4 registers) the intcon, pir1, pir2, pir3 and pir4 registers record individual interrupts via interrupt flag bits. inter- rupt flag bits will be set, regardless of the status of the gie, peie and individual interrupt enable bits. the following events happen when an interrupt event occurs while the gie bit is set: ? current prefetched instruction is flushed ? gie bit is cleared ? current program counter (pc) is pushed onto the stack ? critical registers are automatically saved to the shadow registers (see ? section 7.5 ?automatic context saving? .? ) ? pc is loaded with the interrupt vector 0004h the firmware within the interrupt service routine (isr) should determine the source of the interrupt by polling the interrupt flag bits. the interrupt flag bits must be cleared before exiting the isr to avoid repeated interrupts. because the gie bit is cleared, any interrupt that occurs while executing the isr will be recorded through its interrupt flag, but will not cause the processor to redirect to the interrupt vector. the retfie instruction exits the isr by popping the previous address from the stack, restoring the saved context from the shadow registers and setting the gie bit. for additional information on a specific interrupt?s operation, refer to its peripheral chapter. 7.2 interrupt latency interrupt latency is defined as the time from when the interrupt event occurs to the time code execution at the interrupt vector begins. the latency for synchronous interrupts is 3 or 4 instruction cycles. for asynchronous interrupts, the latency is 3 to 5 instruction cycles, depending on when the interrupt occurs. see figure 7-3 and figure 7-4 for more details. note 1: individual interrupt flag bits are set, regardless of the state of any other enable bits. 2: all interrupts will be ignored while the gie bit is cleared. any interrupt occurring while the gie bit is clear will be serviced when the gie bit is set again.
pic16(l)f1946/1947 ds41414c-page 90 preliminary ? 2010-2011 microchip technology inc. figure 7-3: interrupt latency 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 clkout pc 0004h 0005h pc inst(0004h) nop gie q1 q2 q3 q4 q1 q2 q3 q4 1 cycle instruction at pc pc inst(0004h) nop 2 cycle instruction at pc fsr addr pc+1 pc+2 0004h 0005h pc inst(0004h) nop gie pc pc-1 3 cycle instruction at pc execute interrupt inst(pc) interrupt sampled during q1 inst(pc) pc-1 pc+1 nop pc new pc/ pc+1 0005h pc-1 pc+1/fsr addr 0004h nop interrupt gie interrupt inst(pc) nop nop fsr addr pc+1 pc+2 0004h 0005h pc inst(0004h) nop gie pc pc-1 3 cycle instruction at pc interrupt inst(pc) nop nop nop inst(0005h) execute execute execute
? 2010-2011 microchip technology inc. preliminary ds41414c-page 91 pic16(l)f1946/1947 figure 7-4: int pin interrupt timing q2 q1 q3 q4 q2 q1 q3 q4 q2 q1 q3 q4 q2 q1 q3 q4 q2 q1 q3 q4 osc1 clkout int pin intf gie instruction flow pc instruction fetched instruction executed interrupt latency pc pc + 1 pc + 1 0004h 0005h inst (0004h) inst (0005h) dummy cycle inst (pc) inst (pc + 1) inst (pc ? 1) inst (0004h) dummy cycle inst (pc) ? note 1: intf flag is sampled here (every q1). 2: asynchronous interrupt latency = 3-5 t cy . synchronous latency = 3-4 t cy , where t cy = instruction cycle time. latency is the same whether inst (pc) is a single cycle or a 2-cycle instruction. 3: clkout not available in all oscillator modes. 4: for minimum width of int pulse, refer to ac specifications in section 30.0 ?electrical specifications? ? . 5: intf is enabled to be set any time during the q4-q1 cycles. (1) (2) (3) (4) (5) (1)
pic16(l)f1946/1947 ds41414c-page 92 preliminary ? 2010-2011 microchip technology inc. 7.3 interrupts during sleep some interrupts can be used to wake from sleep. to wake from sleep, the peripheral must be able to operate without the system clock. the interrupt source must have the appropriate interrupt enable bit(s) set prior to entering sleep. on waking from sleep, if the gie bit is also set, the processor will branch to the interrupt vector. otherwise, the processor will continue executing instructions after the sleep instruction. the instruction directly after the sleep instruction will always be executed before branching to the isr. refer to the section 9.0 ?power- down mode (sleep)? for more details. 7.4 int pin the int pin can be used to generate an asynchronous edge-triggered interrupt. this interrupt is enabled by setting the inte bit of the intcon register. the intedg bit of the option r egister determines on which edge the interrupt will occur. when the intedg bit is set, the rising edge will cause the interrupt. when the intedg bit is clear, the falling edge will cause the interrupt. the intf bit of the intcon register will be set when a valid edge appears on the int pin. if the gie and inte bits are also set, the processor will redirect program execution to the interrupt vector. 7.5 automatic context saving upon entering an interrupt, the return pc address is saved on the stack. additionally, the following registers are automatically saved in the shadow registers: ? w register ? status register (except for to and pd ) ? bsr register ? fsr registers ? pclath register upon exiting the interrupt service routine, these regis- ters are automatically restored. any modifications to these registers during the isr will be lost. if modifica- tions to any of these registers are desired, the corre- sponding shadow register should be modified and the value will be restored when exiting the isr. the shadow registers are available in bank 31 and are readable and writable. depending on the user?s appli- cation, other registers may also need to be saved.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 93 pic16(l)f1946/1947 7.5.1 intcon register the intcon register is a readable and writable register, which contains the various enable and flag bits for tmr0 register overflow, interrupt-on-change and external int pin interrupts. note: interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit, gie, of the intcon register. user software should ensure the appropri- ate interrupt flag bits are clear prior to enabling an interrupt. register 7-1: intcon: interrupt control register r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r-0/0 gie peie tmr0ie inte iocie tmr0if intf iocif bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 gie: global interrupt enable bit 1 = enables all active interrupts 0 = disables all interrupts bit 6 peie: peripheral interrupt enable bit 1 = enables all active peripheral interrupts 0 = disables all peripheral interrupts bit 5 tmr0ie: timer0 overflow interrupt enable bit 1 = enables the timer0 interrupt 0 = disables the timer0 interrupt bit 4 inte: int external interrupt enable bit 1 = enables the int external interrupt 0 = disables the int external interrupt bit 3 iocie: interrupt-on-change enable bit 1 = enables the interrupt-on-change 0 = disables the interrupt-on-change bit 2 tmr0if: timer0 overflow interrupt flag bit 1 = tmr0 register has overflowed 0 = tmr0 register did not overflow bit 1 intf: int external interrupt flag bit 1 = the int external interrupt occurred 0 = the int external interrupt did not occur bit 0 iocif: interrupt-on-change interrupt flag bit 1 = when at least one of the interrupt-on-change pins changed state 0 = none of the interrupt-on-change pins have changed state note 1: the iocif flag bit is read-only and cleared when all the interrupt-on-change flags in the iocbf register have been cleared by software.
pic16(l)f1946/1947 ds41414c-page 94 preliminary ? 2010-2011 microchip technology inc. 7.5.2 pie1 register the pie1 register contains the interrupt enable bits, as shown in register 7-2 . note: bit peie of the intcon register must be set to enable any peripheral interrupt. register 7-2: pie1: peripheral interrupt enable register 1 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 tmr1gie: timer1 gate interrupt enable bit 1 = enables the timer1 gate acquisition interrupt 0 = disables the timer1 gate acquisition interrupt bit 6 adie: a/d converter (adc) interrupt enable bit 1 = enables the adc interrupt 0 = disables the adc interrupt bit 5 rcie: usart1 receive interrupt enable bit 1 = enables the usart1 receive interrupt 0 = disables the usart1 receive interrupt bit 4 txie: usart1 transmit interrupt enable bit 1 = enables the usart1 transmit interrupt 0 = disables the usart1 transmit interrupt bit 3 sspie: synchronous serial port (mssp1) interrupt enable bit 1 = enables the mssp1 interrupt 0 = disables the mssp1 interrupt bit 2 ccp1ie: ccp1 interrupt enable bit 1 = enables the ccp1 interrupt 0 = disables the ccp1 interrupt bit 1 tmr2ie: tmr2 to pr2 match interrupt enable bit 1 = enables the timer2 to pr2 match interrupt 0 = disables the timer2 to pr2 match interrupt bit 0 tmr1ie: timer1 overflow interrupt enable bit 1 = enables the timer1 overflow interrupt 0 = disables the timer1 overflow interrupt
? 2010-2011 microchip technology inc. preliminary ds41414c-page 95 pic16(l)f1946/1947 7.5.3 pie2 register the pie2 register contains the interrupt enable bits, as shown in register 7-3 . note: bit peie of the intcon register must be set to enable any peripheral interrupt. register 7-3: pie2: peripheral interrupt enable register 2 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 osfie c2ie c1ie eeie bclie lcdie c3ie ccp2ie bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 osfie: oscillator fail interrupt enable bit 1 = enables the oscillator fail interrupt 0 = disables the oscillator fail interrupt bit 6 c2ie: comparator c2 interrupt enable bit 1 = enables the comparator c2 interrupt 0 = disables the comparator c2 interrupt bit 5 c1ie: comparator c1 interrupt enable bit 1 = enables the comparator c1 interrupt 0 = disables the comparator c1 interrupt bit 4 eeie: eeprom write completion interrupt enable bit 1 = enables the eeprom write completion interrupt 0 = disables the eeprom write completion interrupt bit 3 bclie: mssp1 bus collision interrupt enable bit 1 = enables the mssp1 bus collision interrupt 0 = disables the mssp1 bus collision interrupt bit 2 lcdie: lcd module interrupt enable bit 1 = enables the lcd module interrupt 0 = disables the lcd module interrupt bit 1 c3ie: comparator c3 interrupt enable bit 1 = enables the comparator c3 interrupt 0 = disables the comparator c3 interrupt bit 0 ccp2ie: ccp2 interrupt enable bit 1 = enables the ccp2 interrupt 0 = disables the ccp2 interrupt
pic16(l)f1946/1947 ds41414c-page 96 preliminary ? 2010-2011 microchip technology inc. 7.5.4 pie3 register the pie3 register contains the interrupt enable bits, as shown in register 7-4 . note: bit peie of the intcon register must be set to enable any peripheral interrupt. register 7-4: pie3: peripheral interrupt enable register 3 u-0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 u-0 r/w-0/0 u-0 ? ccp5ie ccp4ie ccp3ie tmr6ie ?tmr4ie ? bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 unimplemented: read as ? 0 ? bit 6 ccp5ie: ccp5 interrupt enable bit 1 = enables the ccp5 interrupt 0 = disables the ccp5 interrupt bit 5 ccp4ie: ccp4 interrupt enable bit 1 = enables the ccp4 interrupt 0 = disables the ccp4 interrupt bit 4 ccp3ie: ccp3 interrupt enable bit 1 = enables the ccp3 interrupt 0 = disables the ccp3 interrupt bit 3 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 2 unimplemented: read as ? 0 ? bit 1 tmr4ie: tmr4 to pr4 match interrupt enable bit 1 = enables the tmr4 to pr4 match interrupt 0 = disables the tmr4 to pr4 match interrupt bit 0 unimplemented: read as ? 0 ?
? 2010-2011 microchip technology inc. preliminary ds41414c-page 97 pic16(l)f1946/1947 7.5.5 pie4 register the pie4 register contains the interrupt enable bits, as shown in register 7-5 . note: bit peie of the intcon register must be set to enable any peripheral interrupt. register 7-5: pie4: peripheral interrupt enable register 4 u-0 u-0 r/w-0/0 r/w-0/0 u-0 u-0 r/w-0/0 r/w-0/0 ? ? rc2ie tx2ie ? ? bcl2ie ssp2ie bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-6 unimplemented: read as ? 0 ? bit 5 rc2ie: usart2 receive interrupt enable bit 1 = enables the usart2 receive interrupt 0 = disables the usart2 receive interrupt bit 4 tx2ie: usart2 transmit interrupt enable bit 1 = enables the usart2 transmit interrupt 0 = disables the usart2 transmit interrupt bit 3-2 unimplemented: read as ? 0 ? bit 1 bcl2ie: mssp2 bus collision interrupt enable bit 1 = enables the mssp2 bus collision interrupt 0 = disables the mssp2 bus collision interrupt bit 0 ssp2ie: synchronous serial port (mssp2) interrupt enable bit 1 = enables the mssp2 interrupt 0 = disables the mssp2 interrupt
pic16(l)f1946/1947 ds41414c-page 98 preliminary ? 2010-2011 microchip technology inc. 7.5.6 pir1 register the pir1 register contains the interrupt flag bits, as shown in register 7-6 . note: interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit, gie, of the intcon register. user software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. register 7-6: pir1: peripheral interrupt request register 1 r/w-0/0 r/w-0/0 r-0/0 r-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 tmr1gif: timer1 gate interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 6 adif: a/d converter interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 5 rcif: usart1 receive interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 4 txif: usart1 transmit interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 3 sspif: synchronous serial port (mssp1) interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 2 ccp1if: ccp1 interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 1 tmr2if: timer2 to pr2 interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 0 tmr1if: timer1 overflow interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending
? 2010-2011 microchip technology inc. preliminary ds41414c-page 99 pic16(l)f1946/1947 7.5.7 pir2 register the pir2 register contains the interrupt flag bits, as shown in register 7-7 . note: interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit, gie, of the intcon register. user software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. register 7-7: pir2: peripheral interrupt request register 2 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 u-0 r/w-0/0 osfif c2if c1if eeif bclif lcdif ? ccp2if bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 osfif: oscillator fail interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 6 c2if: comparator c2 interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 5 c1if: comparator c1 interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 4 eeif: eeprom write completion interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 3 bclif: mssp1 bus collision interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 2 lcdif: lcd module interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 1 unimplemented: read as ? 0 ? bit 0 ccp2if: ccp2 interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending
pic16(l)f1946/1947 ds41414c-page 100 preliminary ? 2010-2011 microchip technology inc. 7.5.8 pir3 register the pir3 register contains the interrupt flag bits, as shown in register 7-8 . note: interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit, gie, of the intcon register. user software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. register 7-8: pir3: peripheral interrupt request register 3 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 ? ccp5if ccp4if ccp3if tmr6if ?tmr4if ? bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 unimplemented: read as ? 0 ? bit 6 ccp5if: ccp5 interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 5 ccp4if: ccp4 interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 4 ccp3if: ccp3 interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 3 tmr6if: tmr6 to pr6 match interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 2 unimplemented: read as ? 0 ? bit 1 tmr4if: tmr4 to pr4 match interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 0 unimplemented: read as ? 0 ?
? 2010-2011 microchip technology inc. preliminary ds41414c-page 101 pic16(l)f1946/1947 7.5.9 pir4 register the pir4 register contains the interrupt flag bits, as shown in register 7-9 . note: interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit, gie, of the intcon register. user software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. register 7-9: pir4: peripheral interrupt request register 4 u-0 u-0 r/w-0/0 r/w-0/0 u-0 u-0 r/w-0/0 r/w-0/0 ? ? rc2if tx2if ? ? bcl2if ssp2if bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-6 unimplemented: read as ? 0 ? bit 5 rc2if: usart2 receive interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 4 tx2if: usart2 transmit interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 3-2 unimplemented: read as ? 0 ? bit 1 bcl2if: mssp2 bus collision interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending bit 0 ssp2if: synchronous serial port (mssp2) interrupt flag bit 1 = interrupt is pending 0 = interrupt is not pending
pic16(l)f1946/1947 ds41414c-page 102 preliminary ? 2010-2011 microchip technology inc. table 7-1: summary of registers associated with interrupts name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 option_reg wpuen intedg t0cs t0se psa ps<2:0> 195 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie2 osfie c2ie c1ie eeie bclie lcdie c3ie ccp2ie 95 pie3 ? ccp5ie ccp4ie ccp3ie tmr6ie ?tmr4ie ?96 pie4 ? ? rc2ie tx2ie ? ? bcl2ie ssp2ie 97 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir2 osfif c2if c1if eeif bclif lcdif c3if ccp2if 99 pir3 ? ccp5if ccp4if ccp3if tmr6if ?tmr4if ? 100 pir4 ? ? rc2if tx2if ? ? bcl2if ssp2if 101 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by interrupts.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 103 pic16(l)f1946/1947 8.0 low dropout (ldo) voltage regulator the pic16f1946/47 has an internal low dropout regulator (ldo) which provides operation above 3.6v. the ldo regulates a voltage for the internal device logic while permitting the v dd and i/o pins to operate at a higher voltage. there is no user enable/disable control available for the ldo, it is always active. the pic16lf1946/47 operates at a maximum v dd of 3.6v and does not incorporate an ldo. a device i/o pin may be configured as the ldo voltage output, identified as the v cap pin. although not required, an external low-esr capacitor may be con- nected to the v cap pin for additional regulator stability. the vcapen bit of configuration word 2 determines which pin is assigned as the v cap pin. refer to tab le 8 - 1 . on power-up, the external capacitor will load the ldo voltage regulator. to prevent erroneous operation, the device is held in reset while a constant current source charges the external capacitor. after the cap is fully charged, the device is released from reset. for more information on recommended capacitor values and the constant current rate, refer to the ldo regulator characteristics table in section 30.0 ?electrical specifications? . table 8-2: summary of configuration word with ldo table 8-1: vcapen<1:0> select bits vcapen<1:0> pin 00 rf0 11 no vcap name bits bit -/7 bit -/6 bit 13/5 bit 12/4 bit 11/3 bit 10/2 bit 9/1 bit 8/0 register on page config2 13:8 ? ? lvp debug ? borv stvren pllen 58 7:0 ? ? ? vcapen ? ? wrt1 wrt0 legend: ? = unimplemented locations read as ? 0 ?. shaded cells are not used by ldo.
pic16(l)f1946/1947 ds41414c-page 104 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 105 pic16(l)f1946/1947 9.0 power-down mode (sleep) the power-down mode is entered by executing a sleep instruction. upon entering sleep mode, the following conditions exist: 1. wdt will be cleared but keeps running, if enabled for operation during sleep. 2. pd bit of the status register is cleared. 3. to bit of the status register is set. 4. cpu clock is disabled. 5. 31 khz lfintosc is unaffected and peripherals that operate from it may continue operation in sleep. 6. timer1 oscillator is unaffected and peripherals that operate from it may continue operation in sleep. 7. adc is unaffected, if the dedicated frc clock is selected. 8. capacitive sensing oscillator is unaffected. 9. i/o ports maintain the status they had before sleep was executed (driving high, low or high- impedance). 10. resets other than wdt are not affected by sleep mode. refer to individual chapters for more details on peripheral operation during sleep. to minimize current consumption, the following condi- tions should be considered: ? i/o pins should not be floating ? external circuitry sinking current from i/o pins ? internal circuitry sourcing current from i/o pins ? current draw from pins with internal weak pull-ups ? modules using 31 khz lfintosc ? modules using timer1 oscillator i/o pins that are high-impedance inputs should be pulled to v dd or v ss externally to avoid switching currents caused by floating inputs. examples of internal circuitry that might be sourcing current include modules such as the dac and fvr modules. see section 17.0 ?digital-to-analog con- verter (dac) module? and section 14.0 ?fixed volt- age reference (fvr)? for more information on these modules. 9.1 wake-up from sleep the device can wake-up from sleep through one of the following events: 1. external reset input on mclr pin, if enabled 2. bor reset, if enabled 3. por reset 4. watchdog timer, if enabled 5. any external interrupt 6. interrupts by peripherals capable of running dur- ing sleep (see individual peripheral for more information) the first three events will cause a device reset. the last three events are considered a continuation of pro- gram execution. to determine whether a device reset or wake-up event occurred, refer to section 6.10 ?determining the cause of a reset? . when the sleep instruction is being executed, the next instruction (pc + 1) is prefetched. for the device to wake-up through an interrupt event, the corresponding interrupt enable bit must be enabled. wake-up will occur regardless of the state of the gie bit. if the gie bit is disabled, the device continues execution at the instruction after the sleep instruction. if the gie bit is enabled, the device executes the instruction after the sleep instruction, the device will call the interrupt service routine. in cases where the execution of the instruction following sleep is not desirable, the user should have a nop after the sleep instruction. the wdt is cleared when the device wakes up from sleep, regardless of the source of wake-up.
pic16(l)f1946/1947 ds41414c-page 106 preliminary ? 2010-2011 microchip technology inc. 9.1.1 wake-up using interrupts when global interrupts are disabled (gie cleared) and any interrupt source has both its interrupt enable bit and interrupt flag bit set, one of the following will occur: ? if the interrupt occurs before the execution of a sleep instruction - sleep instruction will execute as a nop . - wdt and wdt prescaler will not be cleared -to bit of the status register will not be set -pd bit of the status register will not be cleared. ? if the interrupt occurs during or after the execu- tion of a sleep instruction - sleep instruction will be completely exe- cuted - device will immediately wake-up from sleep - wdt and wdt prescaler will be cleared -to bit of the status register will be set -pd bit of the status register will be cleared. even if the flag bits were checked before executing a sleep instruction, it may be possible for flag bits to become set before the sleep instruction completes. to determine whether a sleep instruction executed, test the pd bit. if the pd bit is set, the sleep instruction was executed as a nop . figure 9-1: wake-up from sleep through interrupt table 9-1: summary of registers as sociated with power-down mode q1 q2 q3 q4 q1 q2 q3 q4 q1 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 osc1 (1) clkout (2) interrupt flag gie bit (intcon reg.) instruction flow pc instruction fetched instruction executed pc pc + 1 pc + 2 inst(pc) = sleep inst(pc - 1) inst(pc + 1) sleep processor in sleep interrupt latency (4) inst(pc + 2) inst(pc + 1) inst(0004h) inst(0005h) inst(0004h) dummy cycle pc + 2 0004h 0005h dummy cycle t ost (3) pc + 2 note 1: xt, hs or lp oscillator mode assumed. 2: clkout is not available in xt, hs or lp oscillator modes, but shown here for timing reference. 3: t ost = 1024 t osc (drawing not to scale). this delay applies only to xt, hs or lp oscillator modes. 4: gie = 1 assumed. in this case after wake-up, the processor calls the isr at 0004h. if gie = 0 , execution will continue in-line. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 iocbf iocbf7 iocbf6 iocbf5 iocbf4 iocbf3 iocbf2 iocbf1 iocbf0 153 iocbn iocbn7 iocbn6 iocbn5 iocbn 4 iocbn3 iocbn2 iocbn1 iocbn0 153 iocbp iocbp7 iocbp6 iocbp5 iocbp4 iocbp3 iocbp2 iocbp1 iocbp0 152 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie2 osfie c2ie c1ie eeie bclie lcdie c3ie ccp2ie 95 pie3 ? ccp5ie ccp4ie ccp3ie tmr6ie ?tmr4ie ?96 pie4 ? ? rc2ie tx2ie ? ? bcl2ie ssp2ie 97 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir2 osfif c2if c1if eeif bclif lcdif c3if ccp2if 99 pir3 ? ccp5if ccp4if ccp3if tmr6if ?tmr4if ? 100 pir4 ? ? rc2if tx2if ? ? bcl2if ssp2if 101 status ? ? ?to pd zdcc 25 wdtcon ? ? wdtps<4:0> swdten 109 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used in power-down mode.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 107 pic16(l)f1946/1947 10.0 watchdog timer the watchdog timer is a system timer that generates a reset if the firmware does not issue a clrwdt instruction within the time-out period. the watchdog timer is typically used to recover the system from unexpected events. the wdt has the following features: ? independent clock source ? multiple operating modes - wdt is always on - wdt is off when in sleep - wdt is controlled by software - wdt is always off ? configurable time-out period is from 1 ms to 256 seconds (typical) ? multiple reset conditions ? operation during sleep figure 10-1: watchdog ti mer block diagram lfintosc 23-bit programmable prescaler wdt wdt time-out wdtps<4:0> swdten sleep wdte<1:0> = 11 wdte<1:0> = 01 wdte<1:0> = 10
pic16(l)f1946/1947 ds41414c-page 108 preliminary ? 2010-2011 microchip technology inc. 10.1 independent clock source the wdt derives its time base from the 31 khz lfintosc internal oscillator. 10.2 wdt operating modes the watchdog timer module has four operating modes controlled by the wdte<1:0> bits in configuration word 1. see table 10-1 . 10.2.1 wdt is always on when the wdte bits of configuration word 1 are set to ? 11 ?, the wdt is always on. wdt protection is active during sleep. 10.2.2 wdt is off in sleep when the wdte bits of configuration word 1 are set to ? 10 ?, the wdt is on, except in sleep. wdt protection is not active during sleep. 10.2.3 wdt controlled by software when the wdte bits of configuration word 1 are set to ? 01 ?, the wdt is controlled by the swdten bit of the wdtcon register. wdt protection is unchanged by sleep. see table 10-1 for more details. table 10-1: wdt operating modes 10.3 time-out period the wdtps bits of the wdtcon register set the time-out period from 1 ms to 256 seconds. after a reset, the default time-out period is 2 seconds. 10.4 clearing the wdt the wdt is cleared when any of the following condi- tions occur: ?any reset ? clrwdt instruction is executed ? device enters sleep ? device wakes up from sleep ? oscillator fail event ? wdt is disabled ? oscillator start-up timer (ost) is running see table 10-2 for more information. 10.5 operation during sleep when the device enters sleep, the wdt is cleared. if the wdt is enabled during sleep, the wdt resumes counting. when the device exits sleep, the wdt is cleared again. the wdt remains clear until the ost, if enabled, completes. see section 5.0 ?oscillator module (with fail-safe clock monitor)? for more information on the ost. when a wdt time-out occurs while the device is in sleep, no reset is generated. instead, the device wakes up and resumes operation. the to and pd bits in the status register are changed to indicate the event. see section 3.0 ?memory organization? and status register ( register 3-1 ) for more information. wdte config bits swdten device mode wdt mode wdt_on ( 11 ) x xactive wdt_nsleep ( 10) x awake active wdt_nsleep ( 10 ) x sleep disabled wdt_swdten ( 01 ) 1 xactive wdt_swdten ( 01 ) 0 x disabled wdt_off ( 00 ) x x disabled table 10-2: wdt clearing conditions conditions wdt wdte<1:0> = 00 cleared wdte<1:0> = 01 and swdten = 0 wdte<1:0> = 10 and enter sleep clrwdt command oscillator fail detected exit sleep + system clock = t1osc, extrc, intosc, extclk exit sleep + system clock = xt, hs, lp cleared until the end of ost change intosc divider (ircf bits) unaffected
? 2010-2011 microchip technology inc. preliminary ds41414c-page 109 pic16(l)f1946/1947 register 10-1: wdtcon: wat chdog timer control register u-0 u-0 r/w-0/0 r/w-1/1 r/w-0/0 r/w-1/1 r/w-1/1 r/w-0/0 ? ? wdtps<4:0> swdten bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -m/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-6 unimplemented: read as ? 0 ? bit 5-1 wdtps<4:0>: watchdog timer period select bits bit value = prescale rate 00000 = 1:32 (interval 1 ms typ) 00001 = 1:64 (interval 2 ms typ) 00010 = 1:128 (interval 4 ms typ) 00011 = 1:256 (interval 8 ms typ) 00100 = 1:512 (interval 16 ms typ) 00101 = 1:1024 (interval 32 ms typ) 00110 = 1:2048 (interval 64 ms typ) 00111 = 1:4096 (interval 128 ms typ) 01000 = 1:8192 (interval 256 ms typ) 01001 = 1:16384 (interval 512 ms typ) 01010 = 1:32768 (interval 1s typ) 01011 = 1:65536 (interval 2s typ) (reset value) 01100 = 1:131072 (2 17 ) (interval 4s typ) 01101 = 1:262144 (2 18 ) (interval 8s typ) 01110 = 1:524288 (2 19 ) (interval 16s typ) 01111 = 1:1048576 (2 20 ) (interval 32s typ) 10000 = 1:2097152 (2 21 ) (interval 64s typ) 10001 = 1:4194304 (2 22 ) (interval 128s typ) 10010 = 1:8388608 (2 23 ) (interval 256s typ) 10011 = reserved. results in minimum interval (1:32) ? ? ? 11111 = reserved. results in minimum interval (1:32) bit 0 swdten: software enable/disable for watchdog timer bit if wdte<1:0> = 00 : this bit is ignored. if wdte<1:0> = 01 : 1 = wdt is turned on 0 = wdt is turned off if wdte<1:0> = 1x : this bit is ignored.
pic16(l)f1946/1947 ds41414c-page 110 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 111 pic16(l)f1946/1947 11.0 data eeprom and flash program memory control the data eeprom and flash program memory are readable and writable during normal operation (full v dd range). these memories are not directly mapped in the register file space. instead, they are indirectly addressed through the special function registers (sfrs). there are six sfrs used to access these memories: ? eecon1 ? eecon2 ? eedatl ?eedath ? eeadrl ?eeadrh when interfacing the data memory block, eedatl holds the 8-bit data for read/write, and eeadrl holds the address of the eedatl location being accessed. these devices have 256 bytes of data eeprom with an address range from 0h to 0ffh. when accessing the program memory block, the eed- ath:eedatl register pair forms a 2-byte word that holds the 14-bit data for read/write, and the eeadrl and eeadrh registers form a 2-byte word that holds the 15-bit address of the program memory location being read. the eeprom data memory allows byte read and write. an eeprom byte write automatically erases the loca- tion and writes the new data (erase before write). the write time is controlled by an on-chip timer. the write/erase voltages are generated by an on-chip charge pump rated to operate over the voltage range of the device for byte or word operations. depending on the setting of the flash program memory self write enable bits wrt<1:0> of the configuration word 2, the device may or may not be able to write certain blocks of the program memory. however, reads from the program memory are always allowed. when the device is code-protected, the device programmer can no longer access data or program memory. when code-protected, the cpu may continue to read and write the data eeprom memory and flash program memory. 11.1 eeadrl and eeadrh registers the eeadrh:eeadrl register pair can address up to a maximum of 256 bytes of data eeprom or up to a maximum of 32k words of program memory. when selecting a program address value, the msb of the address is written to the eeadrh register and the lsb is written to the eeadrl register. when selecting a eeprom address value, only the lsb of the address is written to the eeadrl register. 11.1.1 eecon1 and eecon2 registers eecon1 is the control register for ee memory accesses. control bit eepgd determines if the access will be a program or data memory access. when clear, any subsequent operations will operate on the eeprom memory. when set, any subsequent operations will operate on the program memory. on reset, eeprom is selected by default. control bits rd and wr initiate read and write, respectively. these bits cannot be cleared, only set, in software. they are cleared in hardware at completion of the read or write operation. the inability to clear the wr bit in software prevents the accidental, premature termination of a write operation. the wren bit, when set, will allow a write operation to occur. on power-up, the wren bit is clear. the wrerr bit is set when a write operation is interrupted by a reset during normal operation. in these situations, following reset, the user can check the wrerr bit and execute the appropriate error handling routine. interrupt flag bit eeif of the pir2 register is set when write is complete. it must be cleared in the software. reading eecon2 will read all ? 0 ?s. the eecon2 reg- ister is used exclusively in the data eeprom write sequence. to enable writes, a specific pattern must be written to eecon2.
pic16(l)f1946/1947 ds41414c-page 112 preliminary ? 2010-2011 microchip technology inc. 11.2 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 vari- ables or other data that are updated often). when vari- ables in one section change frequently, while variables in another section do not change, it is possible to exceed the total number of write cycles to the eeprom without exceeding the total number of write cycles to a single byte. refer to section 30.0 ?electri- cal specifications? . if this is the case, then a refresh of the array must be performed. for this reason, vari- ables that change infrequently (such as constants, ids, calibration, etc.) should be stored in flash program memory. 11.2.1 reading the data eeprom memory to read a data memory location, the user must write the address to the eeadrl register, clear the eepgd and cfgs control bits of the eecon1 register, and then set control bit rd. the data is available at the very next cycle, in the eedatl register; therefore, it can be read in the next instruction. eedatl will hold this value until another read or until it is written to by the user (during a write operation). example 11-1: data eeprom read 11.2.2 writing to the data eeprom memory to write an eeprom data location, the user must first write the address to the eeadrl register and the data to the eedatl register. then the user must follow a specific sequence to initiate the write for each byte. the write will not initiate if the above sequence is not followed exactly (write 55h to eecon2, write aah to eecon2, then set the wr bit) for each byte. interrupts should be disabled during this code segment. additionally, the wren bit in eecon1 must be set to enable write. this mechanism prevents accidental writes to data eeprom due to errant (unexpected) code execution (i.e., lost programs). the user should keep the wren bit clear at all times, except when updating eeprom. the wren bit is not cleared by hardware. after a write sequence has been initiated, clearing the wren bit will not affect this write cycle. the wr bit will be inhibited from being set unless the wren bit is set. at the completion of the write cycle, the wr bit is cleared in hardware and the ee write complete interrupt flag bit (eeif) is set. the user can either enable this interrupt or poll this bit. eeif must be cleared by software. 11.2.3 protection against spurious write there are conditions when the user may not want to write to the data eeprom memory. to protect against spurious eeprom writes, various mechanisms have been built-in. on power-up, wren is cleared. also, the power-up timer (64 ms duration) prevents eeprom write. the write initiate sequence and the wren bit together help prevent an accidental write during: ? brown-out ? power glitch ? software malfunction 11.2.4 data eeprom operation during code-protect data memory can be code-protected by programming the cpd bit in the configuration word 1 ( register 4-1 ) to ? 0 ?. when the data memory is code-protected, only the cpu is able to read and write data to the data eeprom. it is recommended to code-protect the pro- gram memory when code-protecting data memory. this prevents anyone from replacing your program with a program that will access the contents of the data eeprom. note: data eeprom can be read regardless of the setting of the cpd bit. banksel eeadrl ; movlw data_ee_addr ; movwf eeadrl ;data memory ;address to read bcf eecon1, cfgs ;deselect config space bcf eecon1, eepgd;point to data memory bsf eecon1, rd ;ee read movf eedatl, w ;w = eedatl
? 2010-2011 microchip technology inc. preliminary ds41414c-page 113 pic16(l)f1946/1947 example 11-2: data eeprom write figure 11-1: flash program me mory read cycle execution banksel eeadrl ; movlw data_ee_addr ; movwf eeadrl ;data memory address to write movlw data_ee_data ; movwf eedatl ;data memory value to write bcf eecon1, cfgs ;deselect configuration space bcf eecon1, eepgd ;point to data memory bsf eecon1, wren ;enable writes bcf intcon, gie ;disable ints. movlw 55h ; movwf eecon2 ;write 55h movlw 0aah ; movwf eecon2 ;write aah bsf eecon1, wr ;set wr bit to begin write bsf intcon, gie ;enable interrupts bcf eecon1, wren ;disable writes btfsc eecon1, wr ;wait for write to complete goto $-2 ;done required sequence q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 bsf eecon1,rd executed here instr(pc + 1) executed here forced nop executed here pc pc + 1 eeadrh,eeadrl pc+3 pc + 5 flash addr rd bit eedath,eedatl pc + 3 pc + 4 instr (pc + 1) instr(pc - 1) executed here instr(pc + 3) executed here instr(pc + 4) executed here flash data eedath eedatl register eerhlt instr (pc) instr (pc + 3) instr (pc + 4)
pic16(l)f1946/1947 ds41414c-page 114 preliminary ? 2010-2011 microchip technology inc. 11.3 flash program memory overview it is important to understand the flash program mem- ory structure for erase and programming operations. flash program memory is arranged in rows. a row con- sists of a fixed number of 14-bit program memory words. a row is the minimum block size that can be erased by user software. flash program memory may only be written or erased if the destination address is in a segment of memory that is not write-protected, as defined in bits wrt<1:0> of configuration word 2. after a row has been erased, the user can reprogram all or a portion of this row. data to be written into the program memory row is written to 14-bit wide data write latches. these write latches are not directly accessible to the user, but may be loaded via sequential writes to the eedath:eedatl register pair. the number of data write latches may not be equivalent to the number of row locations. during programming, user software may need to fill the set of write latches and initiate a programming operation multiple times in order to fully reprogram an erased row. for example, a device with a row size of 32 words and eight write latches will need to load the write latches with data and initiate a programming operation four times. the size of a program memory row and the number of program memory write latches may vary by device. see table 11-1 for details. 11.3.1 reading the flash program memory to read a program memory location, the user must: 1. write the least and most significant address bits to the eeadrh:eeadrl register pair. 2. clear the cfgs bit of the eecon1 register. 3. set the eepgd control bit of the eecon1 register. 4. then, set control bit rd of the eecon1 register. once the read control bit is set, the program memory flash controller will use the second instruction cycle to read the data. this causes the second instruction immediately following the ? bsf eecon1,rd ? instruction to be ignored. the data is available in the very next cycle, in the eedath:eedatl register pair; therefore, it can be read as two bytes in the following instructions. eedath:eedatl register pair will hold this value until another read or until it is written to by the user. note: if the user wants to modify only a portion of a previously programmed row, then the contents of the entire row must be read and saved in ram prior to the erase. note 1: the two instructions following a program memory read are required to be nop s. this prevents the user from executing a two-cycle instruction on the next instruction after the rd bit is set. 2: flash program memory can be read regardless of the setting of the cp bit. table 11-1: flash memory organization by device device erase block (row) size/boundary number of write latches/boundary pic16f/lf1946/47 32 words, eeadrl<4:0> = 00000 8 words, eeadrl<2:0> = 000
? 2010-2011 microchip technology inc. preliminary ds41414c-page 115 pic16(l)f1946/1947 example 11-3: flash program memory read * this code block will read 1 word of program * memory at the memory address: prog_addr_hi: prog_addr_lo * data will be returned in the variables; * prog_data_hi, prog_data_lo banksel eeadrl ; select bank for eeprom registers movlw prog_addr_lo ; movwf eeadrl ; store lsb of address movlw prog_addr_hi ; movwl eeadrh ; store msb of address bcf eecon1,cfgs ; do not select configuration space bsf eecon1,eepgd ; select program memory bcf intcon,gie ; disable interrupts bsf eecon1,rd ; initiate read nop ; executed ( figure 11-1 ) nop ; ignored ( figure 11-1 ) bsf intcon,gie ; restore interrupts movf eedatl,w ; get lsb of word movwf prog_data_lo ; store in user location movf eedath,w ; get msb of word movwf prog_data_hi ; store in user location
pic16(l)f1946/1947 ds41414c-page 116 preliminary ? 2010-2011 microchip technology inc. 11.3.2 erasing flash program memory while executing code, program memory can only be erased by rows. to erase a row: 1. load the eeadrh:eeadrl register pair with the address of new row to be erased. 2. clear the cfgs bit of the eecon1 register. 3. set the eepgd, free, and wren bits of the eecon1 register. 4. write 55h, then aah, to eecon2 (flash programming unlock sequence). 5. set control bit wr of the eecon1 register to begin the erase operation. 6. poll the free bit in the eecon1 register to determine when the row erase has completed. see example 11-4 . after the ? bsf eecon1,wr ? instruction, the processor requires two cycles to set up the erase operation. the user must place two nop instructions after the wr bit is set. the processor will halt internal operations for the typical 2 ms erase time. this is not sleep mode as the clocks and peripherals will continue to run. after the erase cycle, the processor will resume operation with the third instruction after the eecon1 write instruction. 11.3.3 writing to flash program memory program memory is programmed using the following steps: 1. load the starting address of the word(s) to be programmed. 2. load the write latches with data. 3. initiate a programming operation. 4. repeat steps 1 through 3 until all data is written. before writing to program memory, the word(s) to be written must be erased or previously unwritten. pro- gram memory can only be erased one row at a time. no automatic erase occurs upon the initiation of the write. program memory can be written one or more words at a time. the maximum number of words written at one time is equal to the number of write latches. see figure 11-2 (block writes to program memory with 16 write latches) for more details. the write latches are aligned to the address boundary defined by eeadrl as shown in ta b l e 11 - 1 . write operations do not cross these boundaries. at the completion of a program memory write operation, the write latches are reset to contain 0x3fff. the following steps should be completed to load the write latches and program a block of program memory. these steps are divided into two parts. first, all write latches are loaded with data except for the last program memory location. then, the last write latch is loaded and the programming sequence is initiated. a special unlock sequence is required to load a write latch with data or initiate a flash programming operation. this unlock sequence should not be interrupted. 1. set the eepgd and wren bits of the eecon1 register. 2. clear the cfgs bit of the eecon1 register. 3. set the lwlo bit of the eecon1 register. when the lwlo bit of the eecon1 register is ? 1 ?, the write sequence will only load the write latches and will not initiate the write to flash program memory. 4. load the eeadrh:eeadrl register pair with the address of the location to be written. 5. load the eedath:eedatl register pair with the program memory data to be written. 6. write 55h, then aah, to eecon2, then set the wr bit of the eecon1 register (flash programming unlock sequence). the write latch is now loaded. 7. increment the eeadrh:eeadrl register pair to point to the next location. 8. repeat steps 5 through 7 until all but the last write latch has been loaded. 9. clear the lwlo bit of the eecon1 register. when the lwlo bit of the eecon1 register is ? 0 ?, the write sequence will initiate the write to flash program memory. 10. load the eedath:eedatl register pair with the program memory data to be written. 11. write 55h, then aah, to eecon2, then set the wr bit of the eecon1 register (flash programming unlock sequence). the entire latch block is now written to flash program memory. it is not necessary to load the entire write latch block with user program data. however, the entire write latch block will be written to program memory. an example of the complete write sequence for eight words is shown in example 11-5 . the initial address is loaded into the eeadrh:eeadrl register pair; the eight words of data are loaded using indirect addressing. note: the code sequence provided in example 11-5 must be repeated multiple times to fully program an erased program memory row.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 117 pic16(l)f1946/1947 after the ? bsf eecon1,wr ? instruction, the processor requires two cycles to set up the write operation. the user must place two nop instructions after the wr bit is set. the processor will halt internal operations for the typical 2 ms, only during the cycle in which the write takes place (i.e., the last word of the block write). this is not sleep mode as the clocks and peripherals will continue to run. the processor does not stall when lwlo = 1 , loading the write latches. after the write cycle, the processor will resume operation with the third instruction after the eecon1 write instruction. figure 11-2: block writes to flash pr ogram memory with 16 write latches 14 14 14 14 program memory buffer register eeadrl<3:0> = 0000 buffer register eeadrl<3:0> = 0001 buffer register eeadrl<3:0> = 0010 buffer register eeadrl<3:0> = 1111 eedata eedath 75 07 0 6 8 first word of block to be written last word of block to be written
pic16(l)f1946/1947 ds41414c-page 118 preliminary ? 2010-2011 microchip technology inc. example 11-4: erasing one row of program memory ; this row erase routine assumes the following: ; 1. a valid address within the erase block is loaded in addrh:addrl ; 2. addrh and addrl are located in shared data memory 0x70 - 0x7f bcf intcon,gie ; disable ints so required sequences will execute properly banksel eeadrl movf addrl,w ; load lower 8 bits of erase address boundary movwf eeadrl movf addrh,w ; load upper 6 bits of erase address boundary movwf eeadrh bsf eecon1,eepgd ; point to program memory bcf eecon1,cfgs ; not configuration space bsf eecon1,free ; specify an erase operation bsf eecon1,wren ; enable writes movlw 55h ; start of required sequence to initiate erase movwf eecon2 ; write 55h movlw 0aah ; movwf eecon2 ; write aah bsf eecon1,wr ; set wr bit to begin erase nop ; any instructions here are ignored as processor ; halts to begin erase sequence nop ; processor will stop here and wait for erase complete. ; after erase processor continues with 3rd instruction bcf eecon1,wren ; disable writes bsf intcon,gie ; enable interrupts required sequence
? 2010-2011 microchip technology inc. preliminary ds41414c-page 119 pic16(l)f1946/1947 example 11-5: writing to flash program memory ; this write routine assumes the following: ; 1. the 16 bytes of data are loaded, starting at the address in data_addr ; 2. each word of data to be written is made up of two adjacent bytes in data_addr, ; stored in little endian format ; 3. a valid starting address (the least significant bits = 000) is loaded in addrh:addrl ; 4. addrh and addrl are located in shared data memory 0x70 - 0x7f ; bcf intcon,gie ; disable ints so required sequences will execute properly banksel eeadrh ; bank 3 movf addrh,w ; load initial address movwf eeadrh ; movf addrl,w ; movwf eeadrl ; movlw low data_addr ; load initial data address movwf fsr0l ; movlw high data_addr ; load initial data address movwf fsr0h ; bsf eecon1,eepgd ; point to program memory bcf eecon1,cfgs ; not configuration space bsf eecon1,wren ; enable writes bsf eecon1,lwlo ; only load write latches loop moviw fsr0++ ; load first data byte into lower movwf eedatl ; moviw fsr0++ ; load second data byte into upper movwf eedath ; movf eeadrl,w ; check if lower bits of address are '000' xorlw 0x07 ; check if we're on the last of 8 addresses andlw 0x07 ; btfsc status,z ; exit if last of eight words, goto start_write ; movlw 55h ; start of required write sequence: movwf eecon2 ; write 55h movlw 0aah ; movwf eecon2 ; write aah bsf eecon1,wr ; set wr bit to begin write nop ; any instructions here are ignored as processor ; halts to begin write sequence nop ; processor will stop here and wait for write to complete. ; after write processor continues with 3rd instruction. incf eeadrl,f ; still loading latches increment address goto loop ; write next latches start_write bcf eecon1,lwlo ; no more loading latches - actually start flash program ; memory write movlw 55h ; start of required write sequence: movwf eecon2 ; write 55h movlw 0aah ; movwf eecon2 ; write aah bsf eecon1,wr ; set wr bit to begin write nop ; any instructions here are ignored as processor ; halts to begin write sequence nop ; processor will stop here and wait for write complete. ; after write processor continues with 3rd instruction bcf eecon1,wren ; disable writes bsf intcon,gie ; enable interrupts required sequence required sequence
pic16(l)f1946/1947 ds41414c-page 120 preliminary ? 2010-2011 microchip technology inc. 11.4 modifying flash program memory when modifying existing data in a program memory row, and data within that row must be preserved, it must first be read and saved in a ram image. program memory is modified using the following steps: 1. load the starting address of the row to be modified. 2. read the existing data from the row into a ram image. 3. modify the ram image to contain the new data to be written into program memory. 4. load the starting address of the row to be rewritten. 5. erase the program memory row. 6. load the write latches with data from the ram image. 7. initiate a programming operation. 8. repeat steps 6 and 7 as many times as required to reprogram the erased row. 11.5 user id, device id and configuration word access instead of accessing program memory or eeprom data memory, the user id?s, device id/revision id and configuration words can be accessed when cfgs = 1 in the eecon1 register. this is the region that would be pointed to by pc<15> = 1 , but not all addresses are accessible. different access may exist for reads and writes. refer to table 11-2 . when read access is initiated on an address outside the parameters listed in table 11-2 , the eedath:eedatl register pair is cleared. table 11-2: user id, device id and configuration word access (cfgs = 1 ) example 11-3: configuration word and device id access address function read access write access 8000h-8003h user ids yes yes 8006h device id/revision id yes no 8007h-8008h configuration words 1 and 2 yes no * this code block will read 1 word of program memory at the memory address: * prog_addr_lo (must be 00h-08h) data will be returned in the variables; * prog_data_hi, prog_data_lo banksel eeadrl ; select correct bank movlw prog_addr_lo ; movwf eeadrl ; store lsb of address clrf eeadrh ; clear msb of address bsf eecon1,cfgs ; select configuration space bcf intcon,gie ; disable interrupts bsf eecon1,rd ; initiate read nop ; executed (see figure 11-1 ) nop ; ignored (see figure 11-1 ) bsf intcon,gie ; restore interrupts movf eedatl,w ; get lsb of word movwf prog_data_lo ; store in user location movf eedath,w ; get msb of word movwf prog_data_hi ; store in user location
? 2010-2011 microchip technology inc. preliminary ds41414c-page 121 pic16(l)f1946/1947 11.6 write verify depending on the application, good programming practice may dictate that the value written to the data eeprom or program memory should be verified (see example 11-6 ) to the desired value to be written. example 11-6 shows how to verify a write to eeprom. example 11-6: eeprom write verify banksel eedatl ; movf eedatl, w ;eedatl not changed ;from previous write bsf eecon1, rd ;yes, read the ;value written xorwf eedatl, w ; btfss status, z ;is data the same goto write_err ;no, handle error : ;yes, continue
pic16(l)f1946/1947 ds41414c-page 122 preliminary ? 2010-2011 microchip technology inc. 11.7 eeprom control registers register 11-1: eedatl: eeprom data register r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u eedat<7:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 eedat<7:0> : read/write value for eeprom data byte or least significant bits of program memory register 11-2: eedath: eeprom data high byte register u-0 u-0 r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u ? ? eedat<13:8> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-6 unimplemented: read as ? 0 ? bit 5-0 eedat<13:8> : read/write value for most significant bits of program memory register 11-3: eeadrl: eeprom address register r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 eeadr<7:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 eeadr<7:0> : specifies the least significant bits for program memory address or eeprom address
? 2010-2011 microchip technology inc. preliminary ds41414c-page 123 pic16(l)f1946/1947 register 11-4: eeadrh: eeprom address high byte register u-1 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 ? eeadr<14:8> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 unimplemented: read as ? 1 ? bit 6-0 eeadr<14:8> : specifies the most significant bits for program memory address or eeprom address register 11-5: eecon1: eeprom control 1 register r/w-0/0 r/w-0/0 r/w-0/0 r/w/hc-0/0 r/w-x/q r/w-0/0 r/s/hc-0/0 r/s/hc-0/0 eepgd cfgs lwlo free wrerr wren wr rd bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? s = bit can only be set x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared hc = bit is cleared by hardware bit 7 eepgd: flash program/data eeprom memory select bit 1 = accesses program space flash memory 0 = accesses data eeprom memory bit 6 cfgs: flash program/data eeprom or configuration select bit 1 = accesses configuration, user id and device id registers 0 = accesses flash program or data eeprom memory bit 5 lwlo: load write latches only bit if cfgs = 1 (configuration space) or cfgs = 0 and eepgd = 1 (program flash) : 1 = the next wr command does not initiate a write; only the program memory latches are updated. 0 = the next wr command writes a value from eedath:eedatl into program memory latches and initiates a write of all the data stored in the program memory latches. if cfgs = 0 and eepgd = 0 : (accessing data eeprom) lwlo is ignored. the next wr command initiates a write to the data eeprom. bit 4 free: program flash erase enable bit if cfgs = 1 (configuration space) or cfgs = 0 and eepgd = 1 (program flash) : 1 = performs an erase operation on the next wr command (cleared by hardware after completion of erase). 0 = performs a write operation on the next wr command. if eepgd = 0 and cfgs = 0 : (accessing data eeprom) free is ignored. the next wr command will initiate both a erase cycle and a write cycle.
pic16(l)f1946/1947 ds41414c-page 124 preliminary ? 2010-2011 microchip technology inc. table 11-3: summary of registers associated with data eeprom bit 3 wrerr: eeprom error flag bit 1 = condition indicates an improper program or erase sequence attempt or termination (bit is set automatically on any set attempt (write ? 1 ?) of the wr bit). 0 = the program or erase operation completed normally. bit 2 wren: program/erase enable bit 1 = allows program/erase cycles 0 = inhibits programming/erasing of program flash and data eeprom bit 1 wr: write control bit 1 = initiates a program flash or data eeprom program/erase operation. the operation is self-timed and the bit is cleared by hardware once operation is complete. the wr bit can only be set (not cleared) in software. 0 = program/erase operation to the flash or data eeprom is complete and inactive. bit 0 rd: read control bit 1 = initiates an program flash or data eeprom read. read takes one cycle. rd is cleared in hardware. the rd bit can only be set (not cleared) in software. 0 = does not initiate a program flash or data eeprom data read. register 11-6: eecon2: eeprom control 2 register w-0/0 w-0/0 w-0/0 w-0/0 w-0/0 w-0/0 w-0/0 w-0/0 eeprom control register 2 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? s = bit can only be set x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 data eeprom unlock pattern bits to unlock writes, a 55h must be written first, followed by an aah, before setting the wr bit of the eecon1 register. the value written to this register is used to unlock the writes. there are specific timing requirements on these writes. refer to section 11.2.2 ?writing to the data eeprom memory? for more information. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page eecon1 eepgd cfgs lwlo free wrerr wren wr rd 123 eecon2 eeprom control register 2 (not a physical register) 111* eeadrl eeadrl<7:0> 122 eeadrh ? eeadrh<6:0> 123 eedatl eedatl<7:0> 122 eedath ? ? eedath<5:0> 122 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie2 osfie c2ie c1ie eeie bclie lcdie c3ie ccp2ie 95 pir2 osfif c2if c1if eeif bclif lcdif c3if ccp2if 99 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by data eeprom module. * page provides register information. register 11-5: eecon1: eeprom control 1 register (continued)
? 2010-2011 microchip technology inc. preliminary ds41414c-page 125 pic16(l)f1946/1947 12.0 i/o ports depending on the device selected and peripherals enabled, there are up to five ports available. in general, when a peripheral is enabled, that pin may not be used as a general purpose i/o pin. each port has three registers for its operation. these registers are: ? trisx registers (data direction register) ? portx registers (reads the levels on the pins of the device) ? latx registers (output latch) the data latch (latx registers) is useful for read-modify-write operations on the value that the i/o pins are driving. a write operation to the latx register has the same affect as a write to the corresponding portx register. a read of the latx register reads of the values held in the i/o port latches, while a read of the portx register reads the actual i/o pin value. ports with analog functions also have an anselx register which can disable the digital input and save power. 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 alternate pin function the alternate pin function control (apfcon) register is used to steer specific peripheral input and output functions between different pins. the apfcon register is shown in register 12-1 . for this device family, the following functions can be moved between different pins. ? ccp3/p3c output ? ccp3/p3b output ? ccp2/p2d output ? ccp2/p2c output ? ccp2/p2b output ? ccp2/p2a output ? ccp1/p1c output ? ccp1/p1b output these bits have no effect on the values of any tris register. port and tris overrides will be routed to the correct pin. the unselected pin will be unaffected. q d ck write latx data register i/o pin read portx write portx trisx read latx data bus to peripherals anselx v dd v ss
pic16(l)f1946/1947 ds41414c-page 126 preliminary ? 2010-2011 microchip technology inc. register 12-1: apfcon: alternate pin function co ntrol register r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 p3csel p3bsel p2dsel p2csel p2bsel ccp2sel p1csel p1bsel bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 p3csel: ccp3 pwm c output pin selection bit 0 = p3c function is on re3/p3c/com0 1 = p3c function is on rd3/p3c/seg3 bit 6 p3bsel: ccp3 pwm b output pin selection bit 0 = p3b function is on re4/p3b/com1 1 = p3b function is on rd4/p3b/seg4 bit 5 p2dsel: ccp2 pwm d output pin selection bit 0 = p2d function is on re0/p2d/vlcd1 1 = p2d function is on rd0/p2d/seg0 bit 4 p2csel: ccp2 pwm c output pin selection bit 0 = p2c function is on re1/p2c/vlcd2 1 = p2c function is on rd1/p2c/seg1 bit 3 p2bsel: ccp2 pwm b output pin selection bit 0 = p2b function is on re2/p2b/vlcd3 1 = p2b function is on rd2/p2b/seg2 bit 2 ccp2sel: ccp2 input/output pin selection bit 0 = ccp2/p2a function is on rc1/ccp2/p2a/t1osi/seg32 1 = ccp2/p2a function is on re7/ccp2/p2a/seg31 bit 1 p1csel: ccp1 pwm c output pin selection bit 0 = p1c function is on re5/p1c/com2 1 = p1c function is on rd5/p1c/seg5 bit 0 p1bsel: ccp1 pwm b output pin selection bit 0 = p1b function is on re6/p1b/com3 1 = p1b function is on rd6/p1b/seg6
? 2010-2011 microchip technology inc. preliminary ds41414c-page 127 pic16(l)f1946/1947 12.2 porta registers porta is a 8-bit wide, bidirectional port. the corresponding data direction register is trisa ( register 12-3 ). setting a trisa bit (= 1 ) will make the corresponding porta pin an input (i.e., disable the output driver). clearing a trisa bit (= 0 ) will make the corresponding porta pin an output (i.e., enables output driver and puts the contents of the output latch on the selected pin). example 12-1 shows how to initialize porta. reading the porta register ( register 12-2 ) reads the status of the pins, whereas writing to it will write to the port latch. all write operations are read-modify-write operations. therefore, a write to a port implies that the port pins are read, this value is modified and then written to the port data latch (lata). the trisa register ( register 12-3 ) controls the porta pin output drivers, even when they are being used as analog inputs. the user should ensure the bits in the trisa register are maintained set when using them as analog inputs. i/o pins configured as analog input always read ? 0 ?. 12.2.1 ansela register the ansela register ( register 12-5 ) is used to configure the input mode of an i/o pin to analog. setting the appropriate ansela bit high will cause all digital reads on the pin to be read as ? 0 ? and allow analog functions on the pin to operate correctly. the state of the ansela bits has no affect on digital output functions. a pin with tris clear and ansel set will still operate as a digital output, but the input mode will be analog. this can cause unexpected behavior when executing read-modify-write instructions on the affected port. example 12-1: initializing porta 12.2.2 porta functions and output priorities each porta pin is multiplexed with other functions. the pins, their combined functions and their output priorities are briefly described here. for additional information, refer to the appropriate section in this data sheet. when multiple outputs are enabled, the actual pin control goes to the peripheral with the lowest number in the following lists. analog input functions, such as adc, comparator and capsense inputs, are not shown in the priority lists. these inputs are active when the i/o pin is set for analog mode using the anselx registers. digital output functions may control the pin when it is in analog mode with the priority shown below. ra0 1. an0 (adc) 2. seg33 (lcd) 3. cps0 (csm) ra1 1. seg18 2. cps1 (csm) ra2 1. seg34 (lcd) 2. v ref - (dac) 3. an2 (adc) 4. cps2 (csm) ra3 1. v ref + (dac) 2. seg35 (lcd) 3. an3 (adc) 4. cps3 (csm) ra4 1. seg14 (lcd) 2. t0cki (tmr0) ra5 1. an4 (adc) 2. seg15 (lcd) 3. cps4 (csm) ra6 1. osc2 (enabled by configuration word) 2. clkout (enabled by configuration word) 3. seg36 (lcd) ra7 1. osc1/clkin (enabled by configuration word) 2. seg37 (lcd) note: the ansela register must be initialized to configure an analog channel as a digital input. pins configured as analog inputs will read ? 0 ?. banksel porta ; clrf porta ;init porta banksel lata ;data latch clrf lata ; banksel ansela ; clrf ansela ;digital i/o banksel trisa ; movlw b'11110000' ;set ra<7:4> as inputs movwf trisa ;and set ra<3:0> as ;outputs
pic16(l)f1946/1947 ds41414c-page 128 preliminary ? 2010-2011 microchip technology inc. register 12-2: porta: porta register r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u ra7 ra6 ra5 ra4 ra3 ra2 ra1 ra0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 ra<7:0> : porta i/o value bits (1) 1 = port pin is > v ih 0 = port pin is < v il note 1: writes to porta are actually written to corresponding lata register. reads from porta register is return of actual i/o pin values. register 12-3: trisa: porta tri-state register r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 trisa7 trisa6 trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 trisa<7:0>: porta tri-state control bit 1 = porta pin configured as an input (tri-stated) 0 = porta pin configured as an output register 12-4: lata: porta data latch register r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u lata7 lata6 lata5 lata4 lata3 lata2 lata1 lata0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 lata<7:0> : porta output latch value bits (1) note 1: writes to porta are actually written to corresponding lata register. reads from porta register is return of actual i/o pin values.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 129 pic16(l)f1946/1947 table 12-1: summary of regist ers associated with porta table 12-2: summary of configuration word with porta register 12-5: ansela: porta analog select register u-0 u-0 r/w-1/1 u-0 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 ? ? ansa5 ? ansa3 ansa2 ansa1 ansa0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-6 unimplemented: read as ? 0 ? bit 5 ansa5 : analog select between analog or digital function on pins ra<5>, respectively 0 = digital i/o. pin is assigned to port or digital special function. 1 = analog input. pin is assigned as analog input (1) . digital input buffer disabled. bit 4 unimplemented: read as ? 0 ? bit 3-0 ansa<3:0> : analog select between analog or digital function on pins ra<3:0>, respectively 0 = digital i/o. pin is assigned to port or digital special function. 1 = analog input. pin is assigned as analog input (1) . digital input buffer disabled. note 1: when setting a pin to an analog input, the corresponding tris bit must be set to input mode in order to allow external control of the voltage on the pin. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page adcon0 ? chs<4:0> go/done adon 166 adcon1 adfm adcs<2:0> ? ? adpref<1:0> 167 ansela ? ?ansa5 ? ansa3 ansa2 ansa1 ansa0 129 cpscon0 cpson cpsrm ? ? cpsrng1 cpsrng0 cpsout t0xcs 332 cpscon1 ? ? ? cpsch<4:0> 333 daccon0 dacen daclps dacoe --- dacpss<1:0> --- dacnss 176 lata lata7 lata6 lata5 lata4 lata3 lata2 lata1 lata0 128 lcdse1 se15 se14 se13 se12 se11 se10 se9 se8 341 lcdse2 se23 se22 se21 se20 se19 se18 se17 se16 341 lcdse4 se39 se38 se37 se36 se35 se34 se33 se32 341 option_reg wpuen intedg tmr0cs tmr0se psa ps<2:0> 195 porta ra7 ra6 ra5 ra4 ra3 ra2 ra1 ra0 128 trisa trisa7trisa6trisa5trisa4trisa3trisa2trisa1trisa0 128 legend: x = unknown, u = unchanged, ? = unimplemented locations read as ? 0 ?. shaded cells are not used by porta. name bits bit -/7 bit -/6 bit 13/5 bit 12/4 bit 11/3 bit 10/2 bit 9/1 bit 8/0 register on page config1 13:8 ? ? fcmen ieso clkouten boren<1:0> cpd 56 7:0 cp mclre pwrte wdte<1:0> fosc<2:0> legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by porta.
pic16(l)f1946/1947 ds41414c-page 130 preliminary ? 2010-2011 microchip technology inc. 12.3 portb registers portb is an 8-bit wide, bidirectional port. the corresponding data direction register is trisb ( register 12-7 ). setting a trisb bit (= 1 ) will make the corresponding portb pin an input (i.e., put the corresponding output driver in a high-impedance mode). clearing a trisb bit (= 0 ) will make the corresponding portb pin an output (i.e., enable the output driver and put the contents of the output latch on the selected pin). example 12-2 shows how to initialize portb. reading the portb register ( register 12-6 ) reads the status of the pins, whereas writing to it will write to the port latch. all write operations are read-modify-write operations. therefore, a write to a port implies that the port pins are read, this value is modified and then written to the port data latch (latb). the trisb register ( register 12-7 ) controls the portb pin output drivers, even when they are being used as analog inputs. the user should ensure the bits in the trisb register are maintained set when using them as analog inputs. i/o pins configured as analog input always read ? 0 ?. 12.3.1 weak pull-ups each of the portb pins has an individually configurable internal weak pull-up. control bits wpub<7:0> enable or disable each pull-up (see register 12-9 ). each weak pull-up is automatically turned off when the port pin is configured as an output. all pull-ups are disabled on a power-on reset by the wpuen bit of the option register. 12.3.2 interrupt-on-change all of the portb pins are individually configurable as an interrupt-on-change pin. control bits iocb<7:0> enable or disable the interrupt function for each pin. the interrupt-on-change feature is disabled on a power-on reset. reference section 13.0 ?interrupt-on-change? for more information. example 12-2: initializing portb 12.3.3 portb functions and output priorities each portb pin is multiplexed with other functions. the pins, their combined functions and their output priorities are briefly described here. for additional information, refer to the appropriate section in this data sheet. when multiple outputs are enabled, the actual pin control goes to the peripheral with the lowest number in the following lists. analog input and some digital input functions are not included in the list below. these input functions can remain active when the pin is configured as an output. certain digital input functions, such as the eusart rx signal, override other port functions and are included in the priority list. rb0 1. seg30 (lcd) 2. flt0 (ccp) 3. sri (sr latch) 4. int rb1 1. seg8 (lcd) rb2 1. seg9 (lcd) rb3 1. seg10 (lcd) rb4 1. seg11 (lcd) rb5 1. seg29 (lcd) 2. t1g (tmr1) rb6 1. icspclk (programming) 2. icdclk (enabled by configuration word) 3. seg38 (lcd) rb7 1. icspdat (programming) 2. icddat (enabled by configuration word) 3. seg39 (lcd) banksel portdb; clrf portb ;init portd banksel latdb ;data latch clrf latb ; banksel trisd ; movlw b'11110000' ;set rd<7:4> as inputs movwf trisd ;and set rd<3:0> as ;outputs
? 2010-2011 microchip technology inc. preliminary ds41414c-page 131 pic16(l)f1946/1947 register 12-6: port b: portb register r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u rb7 rb6 rb5 rb4 rb3 rb2 rb1 rb0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 rb<7:0> : portb i/o pin bit 1 = port pin is > v ih 0 = port pin is < v il register 12-7: trisb: po rtb tri-state register r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 trisb<7:0>: portb tri-state control bit 1 = portb pin configured as an input (tri-stated) 0 = portb pin configured as an output register 12-8: latb: portb data latch register r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u latb7 latb6 latb5 latb4 latb3 latb2 latb1 latb0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 latb<7:0> : portb output latch value bits (1) note 1: writes to portb are actually written to corresponding latb register. reads from portb register is return of actual i/o pin values.
pic16(l)f1946/1947 ds41414c-page 132 preliminary ? 2010-2011 microchip technology inc. table 12-3: summary of regist ers associated with portb register 12-9: wpub: weak pull-up portb register r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 wpub7 wpub6 wpub5 wpub4 wpub3 wpub2 wpub1 wpub0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 wpub<7:0> : weak pull-up register bits 1 = pull-up enabled 0 = pull-up disabled note 1: global wpuen bit of the option register must be cleared for individual pull-ups to be enabled. 2: the weak pull-up device is automatically disabled if the pin is in configured as an output. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 iocbp iocbp7 iocbp6 iocbp5 iocbp4 iocbp3 iocbp2 iocbp1 iocbp0 152 iocbn iocbn7 iocbn6 iocbn5 iocbn 4 iocbn3 iocbn2 iocbn1 iocbn0 153 iocbf iocbf7 iocbf6 iocbf5 iocbf4 iocbf3 iocbf2 iocbf1 iocbf0 153 latb latb7 latb6 latb5 latb4 latb3 latb2 latb1 latb0 131 lcdse1 se15 se14 se13 se12 se11 se10 se9 se8 341 lcdse3 se31 se30 se29 se28 se27 se26 se25 se24 341 lcdse4 se39 se38 se37 se36 se35 se34 se33 se32 341 option_reg wpuen intedg tmr0cs tmr0se psa ps<2:0> 195 portb rb7 rb6 rb5 rb4 rb3 rb2 rb1 rb0 131 t1gcon tmr1ge t1gpol t1gtm t1gspm t1ggo/done t1gval t1gss<1:0> 206 trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 131 wpub wpub7 wpub6 wpub5 wpub4 wpub3 wpub2 wpub1 wpub0 132 legend: x = unknown, u = unchanged, - = unimplemented locations read as ? 0 ?. shaded cells are not used by portb.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 133 pic16(l)f1946/1947 12.4 portc registers portc is a 8-bit wide, bidirectional port. the corresponding data direction register is trisc ( register 12-11 ). setting a trisc bit (= 1 ) will make the corresponding portc pin an input (i.e., put the corresponding output driver in a high-impedance mode). clearing a trisc bit (= 0 ) will make the corresponding portc pin an output (i.e., enable the output driver and put the contents of the output latch on the selected pin). example 12-3 shows how to initialize portc. reading the portc register ( register 12-10 ) reads the status of the pins, whereas writing to it will write to the port latch. all write operations are read-modify-write operations. therefore, a write to a port implies that the port pins are read, this value is modified and then written to the port data latch (latc). the trisc register ( register 12-11 ) controls the portc pin output drivers, even when they are being used as analog inputs. the user should ensure the bits in the trisc register are maintained set when using them as analog inputs. i/o pins configured as analog input always read ? 0 ?. example 12-3: initializing portc 12.4.1 portc functions and output priorities each portc pin is multiplexed with other functions. the pins, their combined functions and their output priorities are briefly described here. for additional information, refer to the appropriate section in this data sheet. when multiple outputs are enabled, the actual pin control goes to the peripheral with the lowest number in the following lists. analog input and some digital input functions are not included in the list below. these input functions can remain active when the pin is configured as an output. certain digital input functions override other port functions and are included in the priority list. rc0 1. t1oso (timer1 oscillator) 2. t1cki (tmr1) 3. seg40 (icd) rc1 1. t1osi (timer1 oscillator) 2. ccp2/p2a 3. seg32 (icd) rc2 1. seg13 (lcd) 2. ccp1/p1a rc3 1. seg17 (lcd) 2. scl1 (mssp1) 3. sck1 (mssp1) rc4 1. seg16 (lcd) 2. sda1 (mssp1) 3. sdi1 (mssp1) rc5 1. seg12 (lcd) 2. sdo1 (mssp1) rc6 1. seg27 (lcd) 2. tx1 (eusart1) 3. ck2 (eusart1) rc7 1. seg28 (lcd) 2. dt1 (eusart1) 3. rx1 (eusart1) banksel portc ; clrf portc ;init portc banksel latc ;data latch clrf latc ; banksel trisc ; movlw b'11110000' ;set rc<7:4> as inputs movwf trisc ;and set rc<3:0> as ;outputs
pic16(l)f1946/1947 ds41414c-page 134 preliminary ? 2010-2011 microchip technology inc. register 12-10: portc: portc register r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u rc7 rc6 rc5 rc4 rc3 rc2 rc1 rc0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 rc<7:0> : portc general purpose i/o pin bits 1 = port pin is > v ih 0 = port pin is < v il register 12-11: trisc: po rtc tri-state register r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 trisc<7:0>: portc tri-state control bits 1 = portc pin configured as an input (tri-stated) 0 = portc pin configured as an output register 12-12: latc: portc data latch register r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u latc7 latc6 latc5 latc4 latc3 latc2 latc1 latc0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 latc<7:0> : portc output latch value bits (1) note 1: writes to portc are actually written to corresponding latc register. reads from portc register is return of actual i/o pin values.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 135 pic16(l)f1946/1947 table 12-4: summary of regist ers associated with portc name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page apfcon p3csel p3bsel p2dsel p2csel p2bsel ccp2sel p1csel p1bsel 126 latc latc7 latc6 latc5 latc4 latc3 latc2 latc1 latc0 134 lcdse1 se15 se14 se13 se12 se11 se10 se9 se8 341 lcdse2 se23 se22 se21 se20 se19 se18 se17 se16 341 lcdse3 se31 se30 se29 se28 se27 se26 se25 se24 341 lcdse4 se39 se38 se37 se36 se35 se34 se33 se32 341 lcdse5 ? ? se45 se44 se43 se42 se41 se40 341 portc rc7 rc6 rc5 rc4 rc3 rc2 rc1 rc0 134 rc1sta spen rx9 sren cren adden ferr oerr rx9d 308 rc2sta spen rx9 sren cren adden ferr oerr rx9d 308 ssp1con1 wcol sspov sspen ckp sspm<3:0> 291 ssp2stat smp cke d/a p s r/w ua bf 289 t1con tmr1cs<1:0> t1ckps<1:0> t1oscen t1sync ? tmr1on 205 tx1sta csrc tx9 txen sync ? brgh trmt tx9d 306 tx2sta csrc tx9 txen sync ? brgh trmt tx9d 306 trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 134 legend: x = unknown, u = unchanged, - = unimplemented locations read as ? 0 ?. shaded cells are not used by portc.
pic16(l)f1946/1947 ds41414c-page 136 preliminary ? 2010-2011 microchip technology inc. 12.5 portd registers portd is a 8-bit wide, bidirectional port. the corresponding data direction register is trisd ( register 12-13 ). setting a trisd bit (= 1 ) will make the corresponding portd pin an input (i.e., put the corresponding output driver in a high-impedance mode). clearing a trisd bit (= 0 ) will make the corresponding portd pin an output (i.e., enable the output driver and put the contents of the output latch on the selected pin). example 12-4 shows how to initialize portd. reading the portd register ( register 12-13 ) reads the status of the pins, whereas writing to it will write to the port latch. all write operations are read-modify-write operations. therefore, a write to a port implies that the port pins are read, this value is modified and then written to the port data latch (latd). the trisd register ( register 12-14 ) controls the portd pin output drivers, even when they are being used as analog inputs. the user should ensure the bits in the trisd register are maintained set when using them as analog inputs. i/o pins configured as analog input always read ? 0 ?. example 12-4: initializing portd 12.5.1 portd functions and output priorities each portd pin is multiplexed with other functions. the pins, their combined functions and their output priorities are briefly described here. for additional information, refer to the appropriate section in this data sheet. when multiple outputs are enabled, the actual pin control goes to the peripheral with the lowest number in the following lists. analog input and some digital input functions are not included in the list below. these input functions can remain active when the pin is configured as an output. certain digital input functions override other port functions and are included in the priority list. rd0 1. seg0 (lcd) 2. p2d (ccp) rd1 1. seg1 (lcd) 2. p2c (ccp) rd2 1. p2b (ccp) 2. seg2 (lcd) rd3 1. seg3 (lcd) 2. p3c (ccp) rd4 1. seg4 (lcd) 2. p3d (ccp) 3. sdo2 (ssp2) rd5 1. seg5 (lcd) 2. p1c (ccp) 3. sdi2/sda2 (ssp2) rd6 1. seg5 (lcd) 2. p1b (ccp) 3. sck2/scl2 (ssp2) rd7 1. seg7 (lcd) 2. ss2 (ssp2) banksel portd ; clrf portd ;init portd banksel latd ;data latch clrf latd ; banksel trisd ; movlw b'11110000' ;set rd<7:4> as inputs movwf trisd ;and set rd<3:0> as ;outputs
? 2010-2011 microchip technology inc. preliminary ds41414c-page 137 pic16(l)f1946/1947 register 12-13: portd: portd register r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u rd7 rd6 rd5 rd4 rd3 rd2 rd1 rd0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 rd<7:0> : portd general purpose i/o pin bits 1 = port pin is > v ih 0 = port pin is < v il register 12-14: trisd: po rtd tri-state register r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 trisd7 trisd6 trisd5 trisd4 trisd3 trisd2 trisd1 trisd0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 trisd<7:0>: portd tri-state control bits 1 = portd pin configured as an input (tri-stated) 0 = portd pin configured as an output register 12-15: latd: portd data latch register r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u latd7 latd6 latd5 latd4 latd3 latd2 latd1 latd0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 latd<7:0> : portd output latch value bits (1) note 1: writes to portd are actually written to corresponding latd register. reads from portd register is return of actual i/o pin values.
pic16(l)f1946/1947 ds41414c-page 138 preliminary ? 2010-2011 microchip technology inc. table 12-5: summary of regist ers associated with portd name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page apfcon p3csel p3bsel p2dsel p2csel p2bsel ccp2sel p1csel p1bsel 126 ccpxcon pxm<1:0> (1) dcxb<1:0> ccpxm<3:0> 236 latd latd7 latd6 latd5 latd4 latd3 latd2 latd1 latd0 137 lcdcon lcden slpen werr ? cs<1:0> lmux<1:0> 337 lcdse0 se7 se6 se5 se4 se3 se2 se1 se0 341 portd rd7 rd6 rd5 rd4 rd3 rd2 rd1 rd0 137 trisd trisd7 trisd6 trisd5 trisd4 trisd3 trisd2 trisd1 trisd0 137 legend: x = unknown, u = unchanged, ? = unimplemented locations read as ? 0 ?. shaded cells are not used by portd. note 1: applies to eccp modules only.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 139 pic16(l)f1946/1947 12.6 porte registers porte is an 8-bit wide, bidirectional port. the corresponding data direction register is trise. setting a trise bit (= 1 ) will make the corresponding porte pin an input (i.e., put the corresponding output driver in a high-impedance mode). clearing a trise bit (= 0 ) will make the corresponding porte pin an output (i.e., enable the output driver and put the contents of the output latch on the selected pin). the exception is re3, which is input only and its tris bit will always read as ? 1 ?. example 12-5 shows how to initialize porte. reading the porte register ( register 12-16 ) reads the status of the pins, whereas writing to it will write to the port latch. all write operations are read-modify-write operations. therefore, a write to a port implies that the port pins are read, this value is modified and then written to the port data latch (late). re3 reads ? 0 ? when mclre = 1. 12.6.1 ansele register the ansele register ( register 12-19 ) is used to configure the input mode of an i/o pin to analog. setting the appropriate ansele bit high will cause all digital reads on the pin to be read as ? 0 ? and allow analog functions on the pin to operate correctly. the state of the ansele bits has no affect on digital output functions. a pin with tris clear and ansel set will still operate as a digital output, but the input mode will be analog. this can cause unexpected behavior when executing read-modify-write instructions on the affected port. the trise register ( register 12-17 ) controls the porte pin output drivers, even when they are being used as analog inputs. the user should ensure the bits in the trise register are maintained set when using them as analog inputs. i/o pins configured as analog input always read ? 0 ?. example 12-5: initializing porte 12.6.2 porte functions and output priorities each porte pin is multiplexed with other functions. the pins, their combined functions and their output priorities are briefly described here. for additional information, refer to the appropriate section in this data sheet. when multiple outputs are enabled, the actual pin control goes to the peripheral with the lowest number in the following lists. analog input and some digital input functions are not included in the list below. these input functions can remain active when the pin is configured as an output. certain digital input functions, such as the eusart rx signal, override other port functions and are included in the priority list. re0 1. p2d (ccp) 2. vlcd1 (lcd) re1 1. p2c (ccp) 2. vlcd2 (lcd) re2 1. p2b (ccp) 2. vlcd3 (lcd) re3 1. p3c (ccp) 2. com0 (lcd) re4 1. p3b (ccp) 2. com1 (lcd) re5 1. p1c (ccp) 2. com32(lcd) re6 1. p1b (ccp) 2. com3 (lcd) re7 1. ccp2/p2a (ccp) 2. seg31 (lcd) note: the ansele register must be initialized to configure an analog channel as a digital input. pins configured as analog inputs will read ? 0 ?. banksel porte ; clrf porte ;init porte banksel late ;data latch clrf late ; banksel ansele ; clrf ansele ;digital i/o banksel trise ; movlw b?00001100? ;set re<3:2> as inputs movwf trise ;and set re<1:0> ;as outputs
pic16(l)f1946/1947 ds41414c-page 140 preliminary ? 2010-2011 microchip technology inc. register 12-16: porte: porte register r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u re7 re6 re5 re4 re3 re2 re1 re0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 re<7:0> : porte i/o pin bits 1 = port pin is > v ih 0 = port pin is < v il register 12-17: trise: porte tri-state 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 trise7 trise6 trise5 trise4 trise3 trise2 trise1 trise0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 trise<7:0>: re<7:0> tri-state control bits 1 = porte pin configured as an input (tri-stated) 0 = porte pin configured as an output
? 2010-2011 microchip technology inc. preliminary ds41414c-page 141 pic16(l)f1946/1947 table 12-6: summary of regist ers associated with porte register 12-18: late: porte data latch register r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u late7 late6 late5 late4 late3 late2 late1 late0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 late<7:0> : porte output latch value bits (1) note 1: writes to porte are actually written to corresponding late register. reads from porte register is return of actual i/o pin values. register 12-19: ansele: po rte analog select 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 ? ? ? ? ? anse2 anse1 anse0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 anse<7:0> : analog select between analog or digital function on pins re<7:0>, respectively 0 = digital i/o. pin is assigned to port or digital special function. 1 = analog input. pin is assigned as analog input (1) . digital input buffer disabled. note 1: when setting a pin to an analog input, the corresponding tris bit must be set to input mode in order to allow external control of the voltage on the pin. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page apfcon p3csel p3bsel p2dsel p2csel p2bsel ccp2sel p1csel p1bsel 126 ansele ? ? ? ? ? anse2 anse1 anse0 141 ccpxcon pxm<1:0> (1) dcxb<1:0> ccpxm<3:0> 236 late late7 late6 late5 late4 late3 late2 late1 late0 141 lcdcon lcden slpen werr ? cs<1:0> lmux<1:0> 337 lcdref lcdire lcdirs lcdiri ? vlcd3pe vlcd2pe vlcd1pe ? 339 lcdse2 se31 se30 se29 se28 se27 se26 se25 se24 341 porte re7 re6 re5 re4 re3 re2 re1 re0 140 trise trise7 trise6 trise5 trise4 trise3 trise2 trise1 trise0 140 legend: x = unknown, u = unchanged, ? = unimplemented locations read as ? 0 ?. shaded cells are not used by porte. note 1: applies to eccp modules only.
pic16(l)f1946/1947 ds41414c-page 142 preliminary ? 2010-2011 microchip technology inc. 12.7 portf registers portf is a 8-bit wide, bidirectional port. the corresponding data direction register is trisf ( register 12-21 ). setting a trisf bit (= 1 ) will make the corresponding portf pin an input (i.e., put the corresponding output driver in a high-impedance mode). clearing a trisf bit (= 0 ) will make the corresponding portf pin an output (i.e., enable the output driver and put the contents of the output latch on the selected pin). example 12-4 shows how to initialize portf. reading the portf register ( register 12-13 ) reads the status of the pins, whereas writing to it will write to the port latch. all write operations are read-modify-write operations. therefore, a write to a port implies that the port pins are read, this value is modified and then written to the port data latch (latf). the trisf register ( register 12-14 ) controls the portf pin output drivers, even when they are being used as analog inputs. the user should ensure the bits in the trisf register are maintained set when using them as analog inputs. i/o pins configured as analog input always read ? 0 ?. 12.7.1 anself register the anself register ( register 12-23 ) is used to configure the input mode of an i/o pin to analog. setting the appropriate anself bit high will cause all digital reads on the pin to be read as ? 0 ? and allow analog functions on the pin to operate correctly. the state of the anself bits has no affect on digital output functions. a pin with tris clear and ansel set will still operate as a digital output, but the input mode will be analog. this can cause unexpected behavior when executing read-modify-write instructions on the affected port. example 12-6: initializing portf note: the anself register must be initialized to configure an analog channel as a digital input. pins configured as analog inputs will read ? 0 ?. banksel portf ; clrf portf ;init portf banksel latf ;data latch clrf latf ; banksel anself ; clrf anself ;digital i/o banksel trisf ; movlw b'11110000' ;set rf<7:4> as inputs movwf trisf ;and set rf<3:0> as ;outputs
? 2010-2011 microchip technology inc. preliminary ds41414c-page 143 pic16(l)f1946/1947 12.7.2 portf functions and output priorities each portf pin is multiplexed with other functions. the pins, their combined functions and their output priorities are briefly described here. for additional information, refer to the appropriate section in this data sheet. when multiple outputs are enabled, the actual pin control goes to the peripheral with the lowest number in the following lists. analog input and some digital input functions are not included in the list below. these input functions can remain active when the pin is configured as an output. certain digital input functions override other port functions and are included in the priority list. rf0 1. an16 (adc) 2. cps16 (csm) 3. c12in0- (comparator) 4. seg41 (lcd) 5. v cap (ldo) rf1 1. an6 (adc) 2. cps6 (csm) 3. c2out (comparator) 4. srnq (sr latch) 5. seg19 (lcd) rf2 1. an7 (adc) 2. cps7 (csm) 3. c1out (comparator) 4. seg20 (lcd) 5. srq (sr latch) rf3 1. an8 (adc) 2. cps8 (csm) 3. c123in2- (comparator) 4. seg21 (lcd) rf4 1. an9 (adc) 2. cps9 (csm) 3. c2in+ (comparator) 4. seg22 (lcd) rf5 1. an10 (adc) 2. cps10 (csm) 3. c12in1- (comparator) 4. dacout (dac) 5. seg23 (lcd) rf6 1. an11 (adc) 2. cps11 (csm) 3. c1in+ (comparator) 4. dacout (dac) 5. seg24 (lcd) rf7 1. an5 (adc) 2. cps5 (csm) 3. c123in3- (comparator) 4. ss1 (mssp1) 5. seg25 (lcd)
pic16(l)f1946/1947 ds41414c-page 144 preliminary ? 2010-2011 microchip technology inc. register 12-20: portf: portf register r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u rf7 rf6 rf5 rf4 rf3 rf2 rf1 rf0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 rf<7:0> : portf general purpose i/o pin bits 1 = port pin is > v ih 0 = port pin is < v il register 12-21: trisf: portf tri-state register r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 trisf7 trisf6 trisf5 trisf4 trisf3 trisf2 trisf1 trisf0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 trisf<7:0>: portf tri-state control bits 1 = portf pin configured as an input (tri-stated) 0 = portf pin configured as an output register 12-22: latf: portf data latch register r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u latf7 latf6 latf5 latf4 latf3 latf2 latf1 latf0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 latf<7:0> : portf output latch value bits (1) note 1: writes to portf are actually written to corresponding latf register. reads from portf register is return of actual i/o pin values.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 145 pic16(l)f1946/1947 table 12-7: summary of regist ers associated with portf table 12-8: summary of configuration words associated with portf register 12-23: anself: por tf analog select register r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 ansf7 ansf6 ansf5 ansdf4 ansf3 ansf2 ansdf1 ansf0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 ansf<7:0> : analog select between analog or digital function on pins rf<7:0>, respectively 0 = digital i/o. pin is assigned to port or digital special function. 1 = analog input. pin is assigned as analog input (1) . digital input buffer disabled. note 1: when setting a pin to an analog input, the corresponding tris bit must be set to input mode in order to allow external control of the voltage on the pin. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page adcon0 ? chs<4:0> go/done adon 166 anself ansf7 ansf6 ansf5 ansf4 ansf3 ansf2 ansf1 ansf0 145 ccpxcon pxm<1:0> (1) dcxb<1:0> ccpxm<3:0> 236 cmout ? ? ? ? ? mc3out mc2out mc1out 184 cm1con1 c1intp c1intn c1pch1 c1pch0 ? ? c1nch<1:0> 184 cm2con1 c2intp c2intn c2pch1 c2pch0 ? ? c2nch<1:0> 184 cpscon0 cpson cpsrm ? ? cpsrng<1:0> cpsout t0xcs 332 cpscon1 ? ? ? ? cpsch<3:0> 333 daccon0 dacen daclps dacoe ? dacpss<1:0> ? dacnss 176 latf latf7 latf6 latf5 latf4 latf3 latf2 latf1 latf0 137 lcdcon lcden slpen werr ? cs<1:0> lmux<1:0> 337 lcdse2 se23 se22 se21 se20 se19 se18 se17 se16 341 lcdse3 se31 se30 se29 se28 se27 se26 se25 se24 341 lcdse5 ? ? se45 se44 se43 se42 se41 se40 341 portf rf7rf6rf5rf4rf3rf2rf1rf0 144 srcon0 srlen srclk2 srclk1 srclk0 srqen srnqen srps srpr 190 trisf trisf7 trisf6 trisf5 trisf 4trisf3trisf2trisf1trisf0 144 legend: x = unknown, u = unchanged, ? = unimplemented locations read as ? 0 ?. shaded cells are not used by portf. note 1: applies to eccp modules only. name bits bit -/7 bit -/6 bit 13/5 bit 12/4 bit 11/3 bit 10/2 bit 9/1 bit 8/0 register on page config2 13:8 ? ? lvp debug ? borv stvren pllen 58 7:0 ? ?vcapen ? ? ? wrt<1:0> legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by clock sources.
pic16(l)f1946/1947 ds41414c-page 146 preliminary ? 2010-2011 microchip technology inc. 12.8 portg registers portg is a 8-bit wide, bidirectional port. the corresponding data direction register is trisg ( register 12-25 ). setting a trisg bit (= 1 ) will make the corresponding portg pin an input (i.e., put the corresponding output driver in a high-impedance mode). clearing a trisg bit (= 0 ) will make the corresponding portg pin an output (i.e., enable the output driver and put the contents of the output latch on the selected pin). example 12-4 shows how to initialize portg. reading the portg register ( register 12-24 ) reads the status of the pins, whereas writing to it will write to the port latch. all write operations are read-modify-write operations. therefore, a write to a port implies that the port pins are read, this value is modified and then written to the port data latch (latg). the trisg register ( register 12-25 ) controls the portg pin output drivers, even when they are being used as analog inputs. the user should ensure the bits in the trisg register are maintained set when using them as analog inputs. i/o pins configured as analog input always read ? 0 ?. 12.8.1 anselg register the anselg register ( register 12-27 ) is used to configure the input mode of an i/o pin to analog. setting the appropriate anselg bit high will cause all digital reads on the pin to be read as ? 0 ? and allow analog functions on the pin to operate correctly. the state of the anselg bits has no affect on digital output functions. a pin with tris clear and ansel set will still operate as a digital output, but the input mode will be analog. this can cause unexpected behavior when executing read-modify-write instructions on the affected port. example 12-7: initializing portg 12.8.2 portg functions and output priorities each portg pin is multiplexed with other functions. the pins, their combined functions and their output priorities are briefly described here. for additional information, refer to the appropriate section in this data sheet. when multiple outputs are enabled, the actual pin control goes to the peripheral with the lowest number in the following lists. analog input and some digital input functions are not included in the list below. these input functions can remain active when the pin is configured as an output. certain digital input functions override other port functions and are included in the priority list. rg0 1. ccp3 (ccp) 2. p3a (ccp) 3. seg42 (lcd) rg1 1. an15 (adc) 2. cps15 (csm) 3. tx2 (eusart) 4. ck2 (eusart) 5. c3out (comparator) 6. seg43 (lcd) rg2 1. an14 (adc) 2. cps14 (csm) 3. dt2/rx2 (eusart) 4. c3in+ (comparator) 5. seg44 (lcd) rg3 1. an13 (adc) 2. cps13 (csm) 3. c3in0- (comparator) 4. ccp4 (ccp) 5. p3d (ccp) 6. seg45 (lcd) rg4 1. an12 (adc) 2. cps12 (csm) 3. c3in1- (comparator) 4. ccp5 (ccp) 5. p1d (ccp) 6. seg26 (lcd) rg5 1. v pp /mclr (basic)seg18 (lcd) note: the anselg register must be initialized to configure an analog channel as a digital input. pins configured as analog inputs will read ? 0 ?. banksel portg ; clrf portg ;init portg banksel latg ;data latch clrf latg ; banksel anselg ; clrf anselg ;digital i/o banksel trisg ; movlw b'11110000' ;set rg<7:4> as inputs movwf trisg ;and set rg<3:0> as ;outputs
? 2010-2011 microchip technology inc. preliminary ds41414c-page 147 pic16(l)f1946/1947 register 12-24: portg: portg register u-0 u-0 r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u ? ? rg5 rg4 rg3 rg2 rg1 rg0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = val ue at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-6 unimplemented: read as ? 0 ?. bit 5-0 rg<5:0> : portg general purpose i/o pin bits 1 = port pin is > v ih 0 = port pin is < v il register 12-25: trisg: portg tri-state register u-0 u-0 r-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 ? ? trisg5 trisg4 trisg3 trisg2 trisg1 trisg0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = val ue at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-6 unimplemented: read as ? 0 ?. bit 5 trisg5: portg tri-state control bit this bit (rg5 pin) is an input only and always read as ? 1 ?. bit 4-0 trisg<4:0>: portg tri-state control bits 1 = portg pin configured as an input (tri-stated) 0 = portg pin configured as an output register 12-26: latg: portg data latch register u-0 u-0 r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u ? ? latg5 latg4 latg3 latg2 latg1 latg0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = val ue at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-6 unimplemented: read as ? 0 ?. bit 5-0 latg<5:0> : portg output latch value bits note 1: writes to portg are actually written to corresponding latg register. reads from portg register is return of actual i/o pin values.
pic16(l)f1946/1947 ds41414c-page 148 preliminary ? 2010-2011 microchip technology inc. register 12-27: anselg: po rtg analog select register u-0 u-0 u-0 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 u-0 ? ? ? ansg4 ansg3 ansg2 ansg1 ? bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-5 unimplemented: read as ? 0 ?. bit 4-1 ansg<4:1> : analog select between analog or digital function on pins rg<4:0>, respectively 0 = digital i/o. pin is assigned to port or digital special function. 1 = analog input. pin is assigned as analog input (1) . digital input buffer disabled. bit 0 unimplemented: read as ? 0 ?. note 1: when setting a pin to an analog input, the corresponding tris bit must be set to input mode in order to allow external control of the voltage on the pin. register 12-28: wpug: weak pull-up portg register u-0 u-0 r/w-1/1 u-0 u-0 u-0 u-0 u-0 ? ?wpug5 ? ? ? ? ? bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-6 unimplemented: read as ? 0 ?. bit 5 wpug5 : weak pull-up register bits 1 = pull-up enabled 0 = pull-up disabled bit 4-0 unimplemented: read as ? 0 ?. note 1: global wpuen bit of the option register must be cleared for individual pull-ups to be enabled. 2: the weak pull-up device is automatically disabled if the pin is in configured as an output.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 149 pic16(l)f1946/1947 table 12-9: summary of regist ers associated with portg name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page adcon0 ? chs<4:0> go/done adon 166 anselg ? ? ? ansg4 ansg3 ansg2 ansg1 ?148 ccpxcon pxm<1:0> (1 ) dcxb<1:0> ccpxm<3:0> 236 cmout ? ? ? ? ?mc3out mc2out mc1out 184 cm1con1 c1intp c1intn c1pch1 c1pch0 ? ? c1nch<1:0> 184 cm2con1 c2intp c2intn c2pch1 c2pch0 ? ? c2nch<1:0> 184 cpscon0 cpson cpsrm ? ? cpsrng<1:0> cpsout t0xcs 332 cpscon1 ? ? ? ? cpsch<3:0> 333 latg ? ? ? latg4 latg3 latg2 latg1 latg0 147 lcdcon lcden slpen werr ? cs<1:0> lmux<1:0> 337 lcdse5 ? ? se45 se44 se43 se42 se41 se40 341 portg ? ? rg5 rg4 rg3 rg2 rg1 rg0 147 trisg ? ? trisg5 trisg4 trisg3 trisg2 trisg1 trisg0 147 wpug ? ?wpug5 ? ? ? ? ?148 legend: x = unknown, u = unchanged, ? = unimplemented locations read as ? 0 ?. shaded cells are not used by portg. note 1: applies to eccp modules only.
pic16(l)f1946/1947 ds41414c-page 150 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 151 pic16(l)f1946/1947 13.0 interrupt-on-change the portb pins can be configured to operate as interrupt-on-change (ioc) pins. an interrupt can be generated by detecting a signal that has either a rising edge or a falling edge. any individual portb pin, or combination of portb pins, can be configured to generate an interrupt. the interrupt-on-change module has the following features: ? interrupt-on-change enable (master switch) ? individual pin configuration ? rising and falling edge detection ? individual pin interrupt flags figure 13-1 is a block diagram of the ioc module. 13.1 enabling the module to allow individual portb pins to generate an interrupt, the iocie bit of the intcon register must be set. if the iocie bit is disabled, the edge detection on the pin will still occur, but an interrupt will not be generated. 13.2 individual pin configuration for each portb pin, a rising edge detector and a falling edge detector are present. to enable a pin to detect a rising edge, the associated iocbpx bit of the iocbp register is set. to enable a pin to detect a falling edge, the associated iocbnx bit of the iocbn register is set. a pin can be configured to detect rising and falling edges simultaneously by setting both the iocbpx bit and the iocbnx bit of the iocbp and iocbn registers, respectively. 13.3 interrupt flags the iocbfx bits located in the iocbf register are status flags that correspond to the interrupt-on-change pins of portb. if an expected edge is detected on an appropriately enabled pin, then the status flag for that pin will be set, and an interrupt will be generated if the iocie bit is set. the iocif bit of the intcon register reflects the status of all iocbfx bits. 13.4 clearing interrupt flags the individual status flags, (iocbfx bits), can be cleared by resetting them to zero. if another edge is detected during this clearing operation, the associated status flag will be set at the end of the sequence, regardless of the value actually being written. in order to ensure that no detected edge is lost while clearing flags, only and operations masking out known changed bits should be performed. the following sequence is an example of what should be performed. example 13-1: 13.5 operation in sleep the interrupt-on-change interrupt sequence will wake the device from sleep mode, if the iocie bit is set. if an edge is detected while in sleep mode, the iocbf register will be updated prior to the first instruction executed out of sleep. movlw 0xff xorwf iocbf, w andwf iocbf, f
pic16(l)f1946/1947 ds41414c-page 152 preliminary ? 2010-2011 microchip technology inc. figure 13-1: interrupt-on -change block diagram 13.6 interrupt-on-change registers d ck r q d ck r q iocbnx iocbpx q2 d ck s q q4q1 data bus = 0 or 1 write iocbfx iocie to data bus iocbfx edge detect from all other iocbfx individual pin detectors q1 q2 q3 q4 q4q1 q1 q2 q3 q4 q1 q2 q3 q4 q4 q4q1 q4q1 q4q1 register 13-1: iocbp: interrupt-on- change positive edge register r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 iocbp7 iocbp6 iocbp5 iocbp4 iocbp3 iocbp2 iocbp1 iocbp0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 iocbp<7:0>: interrupt-on-change positive edge enable bits 1 = interrupt-on-change enabled on the pin for a positive going edge. associated status bit and interrupt flag will be set upon detecting an edge. 0 = interrupt-on-change disabled for the associated pin.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 153 pic16(l)f1946/1947 table 13-1: summary of registers associated with interrupt-on-change register 13-2: iocbn: interrupt-on-change negative edge register r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 iocbn7 iocbn6 iocbn5 iocbn4 iocbn3 iocbn2 iocbn1 iocbn0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 iocbn<7:0>: interrupt-on-change negative edge enable bits 1 = interrupt-on-change enabled on the pin for a negative going edge. associated status bit and interrupt flag will be set upon detecting an edge. 0 = interrupt-on-change disabled for the associated pin. register 13-3: iocbf: interrupt-on-change flag register r/w/hs-0/0 r/w/hs-0/0 r/w/hs-0/0 r/w/hs-0/0 r/w/hs-0/0 r/w/hs-0/0 r/w/hs-0/0 r/w/hs-0/0 iocbf7 iocbf6 iocbf5 iocbf4 iocbf3 iocbf2 iocbf1 iocbf0 bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared hs - bit is set in hardware bit 7-0 iocbf<7:0>: interrupt-on-change flag bits 1 = an enabled change was detected on the associated pin. set when iocbpx = 1 and a rising edge was detected on rbx, or when iocbnx = 1 and a falling edge was detected on rbx. 0 = no change was detected, or the user cleared the detected change. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 iocbf iocbf7 iocbf6 iocbf5 iocbf4 iocbf3 iocbf2 iocbf1 iocbf0 153 iocbn iocbn7 iocbn6 iocbn5 iocbn4 iocbn3 iocbn2 iocbn1 iocbn0 153 iocbp iocbp7 iocbp6 iocbp5 ioc bp4 iocbp3 iocbp2 iocbp1 iocbp0 152 trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 131 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by interrupt-on-change.
pic16(l)f1946/1947 ds41414c-page 154 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 155 pic16(l)f1946/1947 14.0 fixed voltage reference (fvr) the fixed voltage reference, or fvr, is a stable voltage reference, independent of v dd , with 1.024v, 2.048v or 4.096v selectable output levels. the output of the fvr can be configured to supply a reference voltage to the following: ? adc input channel ? adc positive reference ? comparator positive input ? digital-to-analog converter (dac) ? capacitive sensing (cps) module ? lcd bias generator the fvr can be enabled by setting the fvren bit of the fvrcon register. 14.1 independent gain amplifiers the output of the fvr supplied to the adc, comparators, dac and cps module is routed through two independent programmable gain amplifiers. each amplifier can be configured to amplify the reference voltage by 1x, 2x or 4x, to produce the three possible voltage levels. the adfvr<1:0> bits of the fvrcon register are used to enable and configure the gain amplifier settings for the reference supplied to the adc module. refer- ence section 16.0 ?analog-to-digital converter (adc) module? for additional information. the cdafvr<1:0> bits of the fvrcon register are used to enable and configure the gain amplifier settings for the reference supplied to the comparators, dac and cps module. reference section 17.0 ?digital-to- analog converter (dac) module? , section 18.0 ?comparator module? and section 26.0 ?capacitive sensing (cps) module? for additional information. 14.2 fvr stabilization period when the fixed voltage reference module is enabled, it requires time for the reference and amplifier circuits to stabilize. once the circuits stabilize and are ready for use, the fvrrdy bit of the fvrcon register will be set. see section 30.0 ?electrical specifications? for the minimum delay requirement. figure 14-1: voltage reference block diagram adfvr<1:0> cdafvr<1:0> x 1 x 2 x 4 x 1 x 2 x 4 2 2 fvr buffer1 (to adc module) fvr buffer2 (to comparators, dac) fvr vref (to lcd bias generator) + _ fvren fvrrdy 1.024v fixed reference
pic16(l)f1946/1947 ds41414c-page 156 preliminary ? 2010-2011 microchip technology inc. 14.3 fvr control registers table 14-1: summary of registers associated with fixed voltage reference register 14-1: fvrcon: fixed voltage reference control register r/w-0/0 r-q/q r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 fvren fvrrdy (1) tsen tsrng cdafvr<1:0> adfvr<1:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared q = value depends on condition bit 7 fvren: fixed voltage reference enable bit 0 = fixed voltage reference is disabled 1 = fixed voltage reference is enabled bit 6 fvrrdy: fixed voltage reference ready flag bit (1) 0 = fixed voltage reference output is not ready or not enabled 1 = fixed voltage reference output is ready for use bit 5 tsen: temperature indicator enable bit (3) 0 = temperature indicator is disabled 1 = temperature indicator is enabled bit 4 tsrng: temperature indicator range selection bit (3) 0 =v out = v dd - 4v t (high range) 1 =v out = v dd - 2v t (low range) bit 3-2 cdafvr<1:0>: comparator and dac fixed voltage reference selection bit 00 = comparator, dac and cps module fixed voltage reference peripheral output is off 01 = comparator, dac and cps module fixed voltage reference peripheral output is 1x (1.024v) 10 = comparator, dac and cps module fixed voltage reference peripheral output is 2x (2.048v) (2) 11 = comparator, dac and cps module fixed voltage reference peripheral output is 4x (4.096v) (2) bit 1-0 adfvr<1:0>: adc fixed voltage reference selection bit 00 = adc fixed voltage reference peripheral output is off 01 = adc fixed voltage reference peripheral output is 1x (1.024v) 10 = adc fixed voltage reference peripheral output is 2x (2.048v) (2) 11 = adc fixed voltage reference peripheral output is 4x (4.096v) (2) note 1: fvrrdy is always ? 1 ? on pic16f1946/47 only. 2: fixed voltage reference output cannot exceed v dd . 3: see section 15.0 ?temperature indicator module? for additional information. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page fvrcon fvren fvrrdy tsen tsrng cdafvr<1:0> adfvr<1:0> 156 legend: shaded cells are not used with the fixed voltage reference.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 157 pic16(l)f1946/1947 15.0 temperature indicator module this family of devices is equipped with a temperature circuit designed to measure the operating temperature of the silicon die. the circuit?s range of operating temperature falls between -40c and +85c. the output is a voltage that is proportional to the device temperature. the output of the temperature indicator is internally connected to the device adc. the circuit may be used as a temperature threshold detector or a more accurate temperature indicator, depending on the level of calibration performed. a one- point calibration allows the circuit to indicate a temperature closely surrounding that point. a two-point calibration allows the circuit to sense the entire range of temperature more accurately. reference application note an1333, ? use and calibration of the internal temperature indicator ? (ds01333) for more details regarding the calibration process. 15.1 circuit operation figure 15-1 shows a simplified block diagram of the temperature circuit. the proportional voltage output is achieved by measuring the forward voltage drop across multiple silicon junctions. equation 15-1 describes the output characteristics of the temperature indicator. equation 15-1: v out ranges the temperature sense circuit is integrated with the fixed voltage reference (fvr) module. see section 14.0 ?fixed voltage reference (fvr)? for more information. the circuit is enabled by setting the tsen bit of the fvrcon register. when disabled, the circuit draws no current. the circuit operates in either high or low range. the high range, selected by setting the tsrng bit of the fvrcon register, provides a wider output voltage. this provides more resolution over the temperature range, but may be less consistent from part to part. this range requires a higher bias voltage to operate and thus, a higher v dd is needed. the low range is selected by clearing the tsrng bit of the fvrcon register. the low range generates a lower voltage drop and thus, a lower bias voltage is needed to operate the circuit. the low range is provided for low voltage operation. figure 15-1: temperature circuit diagram 15.2 minimum operating v dd vs. minimum sensing temperature when the temperature circuit is operated in low range, the device may be operated at any operating voltage that is within specifications. when the temperature circuit is operated in high range, the device operating voltage, v dd , must be high enough to ensure that the temperature circuit is correctly biased. table 15-1 shows the recommended minimum v dd vs. range setting. table 15-1: recommended v dd vs. range 15.3 temperature output the output of the circuit is measured using the internal analog-to-digital converter. channel 29 is reserved for the temperature circuit output. refer to section 16.0 ?analog-to-digital converter (adc) module? for detailed information. high range: v out = v dd - 4v t low range: v out = v dd - 2v t min. v dd , tsrng = 1 min. v dd , tsrng = 0 3.6v 1.8v note: every time the adc mux is changed to the temperature indicator output selection (chs bit in the adccon0 register), wait 500 usec for the sampling capacitor to fully charge before sampling the tempera- ture indicator output. tsen adc mux tsrng v dd adc chs bits (adcon0 register) n v out
pic16(l)f1946/1947 ds41414c-page 158 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 159 pic16(l)f1946/1947 16.0 analog-to-digital converter (adc) module the analog-to-digital converter (adc) allows conversion of an analog input signal to a 10-bit binary representation of that signal. this device uses analog inputs, which are multiplexed into a single sample and hold circuit. the output of the sample and hold is connected to the input of the converter. the converter generates a 10-bit binary result via successive approximation and stores the conversion result into the adc result registers (adresh:adresl register pair). figure 16-1 shows the block diagram of the adc. the adc voltage reference is software selectable to be either internally generated or externally supplied. the adc can generate an interrupt upon completion of a conversion. this interrupt can be used to wake-up the device from sleep.
pic16(l)f1946/1947 ds41414c-page 160 preliminary ? 2010-2011 microchip technology inc. figure 16-1: adc block diagram dac v dd v ref + adpref = 10 adpref = 00 adpref = 11 fvr buffer1 v ss v ref - adnref = 1 adnref = 0 note: when adon = 0 , all multiplexer inputs are disconnected. adon go/done v ss adc 00000 00001 00010 00011 00100 00101 00111 00110 01000 01001 01010 01011 01100 01101 11110 chs<4:0> an0 an1 an2 an4 an5 an6 an7 an3 an8 an9 an10 an11 an12 an13 11111 adresh adresl 10 16 adfm 0 = left justify 1 = right justify 01110 01111 10000 an14 an15 an16 temp indicator 11101
? 2010-2011 microchip technology inc. preliminary ds41414c-page 161 pic16(l)f1946/1947 16.1 adc configuration when configuring and using the adc the following functions must be considered: ? port configuration ? channel selection ? adc voltage reference selection ? adc conversion clock source ? interrupt control ? result formatting 16.1.1 port configuration the adc can be used to convert both analog and digital signals. when converting analog signals, the i/o pin should be configured for analog by setting the associated tris and ansel bits. refer to section 12.0 ?i/o ports? for more information. 16.1.2 channel selection there are 20 selections available: ? an<16:0> pins ? temperature indicator ? dac output ? fvr (fixed voltage reference) output refer to section 15.0 ?temperature indicator mod- ule? , section 17.0 ?digital-to-analog converter (dac) module? and section 14.0 ?fixed voltage reference (fvr)? for more information on these chan- nel selections. the chs bits of the adcon0 register determine which channel is connected to the sample and hold circuit. when changing channels, a delay is required before starting the next conversion. refer to section 16.2 ?adc operation? for more information. 16.1.3 adc voltage reference the adpref bits of the adcon1 register provides control of the positive voltage reference. the positive voltage reference can be: ?v ref + pin ?v dd ? fvr 2.048v ? fvr 4.096v (not available on lf devices) the adnref bit of the adcon1 register provides control of the negative voltage reference. the negative voltage reference can be: ?v ref - pin ?v ss see section 14.0 ?fixed voltage reference (fvr)? for more details on the fixed voltage reference. 16.1.4 conversion clock the source of the conversion clock is software select- able via the adcs bits of the adcon1 register. there are seven possible clock options: ?f osc /2 ?f osc /4 ?f osc /8 ?f osc /16 ?f osc /32 ?f osc /64 ?f rc (dedicated internal oscillator) the time to complete one bit conversion is defined as t ad . one full 10-bit conversion requires 11.5 t ad peri- ods as shown in figure 16-2 . for correct conversion, the appropriate t ad specifica- tion must be met. refer to the a/d conversion require- ments in section 30.0 ?electrical specifications? for more information. table 16-1 gives examples of appro- priate adc clock selections. note: analog voltages on any pin that is defined as a digital input may cause the input buf- fer to conduct excess current. note: unless using the f rc , any changes in the system clock frequency will change the adc clock frequency, which may adversely affect the adc result.
pic16(l)f1946/1947 ds41414c-page 162 preliminary ? 2010-2011 microchip technology inc. table 16-1: adc clock period (t ad ) v s . device operating frequencies figure 16-2: analog-to-dig ital conversion t ad cycles adc clock period (t ad ) device frequency (f osc ) adc clock source adcs<2:0> 32 mhz 20 mhz 16 mhz 8 mhz 4 mhz 1 mhz fosc/2 000 62.5ns (2) 100 ns (2) 125 ns (2) 250 ns (2) 500 ns (2) 2.0 ? s fosc/4 100 125 ns (2) 200 ns (2) 250 ns (2) 500 ns (2) 1.0 ? s4.0 ? s fosc/8 001 0.5 ? s (2) 400 ns (2) 0.5 ? s (2) 1.0 ? s2.0 ? s 8.0 ? s (3) fosc/16 101 800 ns 800 ns 1.0 ? s2.0 ? s4.0 ? s 16.0 ? s (3) fosc/32 010 1.0 ? s1.6 ? s2.0 ? s4.0 ? s 8.0 ? s (3) 32.0 ? s (3) fosc/64 110 2.0 ? s3.2 ? s4.0 ? s 8.0 ? s (3) 16.0 ? s (3) 64.0 ? s (3) f rc x11 1.0-6.0 ? s (1,4) 1.0-6.0 ? s (1,4) 1.0-6.0 ? s (1,4) 1.0-6.0 ? s (1,4) 1.0-6.0 ? s (1,4) 1.0-6.0 ? s (1,4) legend: shaded cells are outside of recommended range. note 1: the f rc source has a typical t ad time of 1.6 ? s for v dd . 2: these values violate the minimum required t ad time. 3: for faster conversion times, the selection of another clock source is recommended. 4: the adc clock period (t ad ) and total adc conversion time can be minimiz ed when the adc clock is derived from the system clock f osc . however, the f rc clock source must be used when conv ersions are to be performed with the device in sleep mode. t ad 1 t ad 2 t ad 3 t ad 4 t ad 5 t ad 6 t ad 7 t ad 8 t ad 11 set go bit holding capacitor is disconnected from analog input (typically 100 ns) t ad 9 t ad 10 t cy - t ad adresh:adresl is loaded, go bit is cleared, adif bit is set, holding capacitor is connected to analog input. conversion starts b0 b9 b6 b5 b4 b3 b2 b1 b8 b7 on the following cycle:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 163 pic16(l)f1946/1947 16.1.5 interrupts the adc module allows for the ability to generate an interrupt upon completion of an analog-to-digital conversion. the adc interrupt flag is the adif bit in the pir1 register. the adc interrupt enable is the adie bit in the pie1 register. the adif bit must be cleared in software. this interrupt can be generated while the device is operating or while in sleep. if the device is in sleep, the interrupt will wake-up the device. upon waking from sleep, the next instruction following the sleep instruc- tion is always executed. if the user is attempting to wake-up from sleep and resume in-line code execu- tion, the gie and peie bits of the intcon register must be disabled. if the gie and peie bits of the intcon register are enabled, execution will switch to the interrupt service routine. 16.1.6 result formatting the 10-bit a/d conversion result can be supplied in two formats, left justified or right justified. the adfm bit of the adcon1 register controls the output format. figure 16-3 shows the two output formats. figure 16-3: 10-bit a/d conv ersion result format note 1: the adif bit is set at the completion of every conversion, regardless of whether or not the adc interrupt is enabled. 2: the adc operates during sleep only when the f rc oscillator is selected. adresh adresl (adfm = 0 )msb lsb bit 7 bit 0 bit 7 bit 0 10-bit a/d result unimplemented: read as ? 0 ? (adfm = 1 ) msb lsb bit 7 bit 0 bit 7 bit 0 unimplemented: read as ? 0 ? 10-bit a/d result
pic16(l)f1946/1947 ds41414c-page 164 preliminary ? 2010-2011 microchip technology inc. 16.2 adc operation 16.2.1 starting a conversion to enable the adc module, the adon bit of the adcon0 register must be set to a ? 1 ?. setting the go/ done bit of the adcon0 register to a ? 1 ? will start the analog-to-digital conversion. 16.2.2 completion of a conversion when the conversion is complete, the adc module will: ? clear the go/done bit ? set the adif interrupt flag bit ? update the adresh and adresl registers with new conversion result 16.2.3 terminating a conversion if a conversion must be terminated before completion, the go/done bit can be cleared in software. the adresh and adresl registers will be updated with the partially complete analog-to-digital conversion sample. incomplete bits will match the last bit converted. 16.3 adc operation during sleep the adc module can operate during sleep. this requires the adc clock source to be set to the f rc option. when the f rc clock source is selected, the adc waits one additional instruction before starting the conversion. this allows the sleep instruction to be executed, which can reduce system noise during the conversion. if the adc interrupt is enabled, the device will wake-up from sleep when the conversion completes. if the adc interrupt is disabled, the adc module is turned off after the conversion completes, although the adon bit remains set. when the adc clock source is something other than f rc , a sleep instruction causes the present conver- sion to be aborted and the adc module is turned off, although the adon bit remains set. 16.3.1 special event trigger the special event trigger of the ccpx/eccpx module allows periodic adc measurements without software intervention. when this trigger occurs, the go/done bit is set by hardware and the timer1 counter resets to zero. using the special event trigger does not assure proper adc timing. it is the user?s responsibility to ensure that the adc timing requirements are met. refer to section 23.0 ?capture/compare/pwm modules? for more information. note: the go/done bit should not be set in the same instruction that turns on the adc. refer to section 16.3.2 ?a/d conver- sion procedure? . note: a device reset forces all registers to their reset state. thus, the adc module is turned off and any pending conversion is terminated. table 16-2: special event trigger device ccpx/eccpx pic16f/lf1946/47 ccp5
? 2010-2011 microchip technology inc. preliminary ds41414c-page 165 pic16(l)f1946/1947 16.3.2 a/d conversion procedure this is an example procedure for using the adc to perform an analog-to-digital conversion: 1. configure port: ? disable pin output driver (refer to the tris register) ? configure pin as analog (refer to the ansel register) 2. configure the adc module: ? select adc conversion clock ? configure voltage reference ? select adc input channel ? turn on adc module 3. configure adc interrupt (optional): ? clear adc interrupt flag ? enable adc interrupt ? enable peripheral interrupt ? enable global interrupt (1) 4. wait the required acquisition time (2) . 5. start conversion by setting the go/done bit. 6. wait for adc conversion to complete by one of the following: ? polling the go/done bit ? waiting for the adc interrupt (interrupts enabled) 7. read adc result. 8. clear the adc interrupt flag (required if interrupt is enabled). example 16-1: a/d conversion note 1: the global interrupt can be disabled if the user is attempting to wake-up from sleep and resume in-line code execution. 2: refer to section 16.5 ?a/d acquisition requirements? . ;this code block configures the adc ;for polling, vdd and vss references, frc ;clock and an0 input. ; ;conversion start & polling for completion ; are included. ; banksel adcon1 ; movlw b?11110000? ;right justify, frc ;clock movwf adcon1 ;vdd and vss vref banksel trisa ; bsf trisa,0 ;set ra0 to input banksel ansel ; bsf ansel,0 ;set ra0 to analog banksel adcon0 ; movlw b?00000001? ;select channel an0 movwf adcon0 ;turn adc on call sampletime ;acquisiton delay bsf adcon0,adgo ;start conversion btfsc adcon0,adgo ;is conversion done? goto $-1 ;no, test again banksel adresh ; movf adresh,w ;read upper 2 bits movwf resulthi ;store in gpr space banksel adresl ; movf adresl,w ;read lower 8 bits movwf resultlo ;store in gpr space
pic16(l)f1946/1947 ds41414c-page 166 preliminary ? 2010-2011 microchip technology inc. 16.4 adc register definitions the following registers are used to control the operation of the adc. register 16-1: adcon0: a/ d control register 0 u-0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 ? chs<4:0> go/done adon bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 unimplemented: read as ? 0 ? bit 6-2 chs<4:0>: analog channel select bits 00000 =an0 00001 =an1 00010 =an2 00011 =an3 00100 =an4 00101 =an5 00110 =an6 00111 =an7 01000 =an8 01001 =an9 01010 =an10 01011 =an11 01100 =an12 01101 =an13 01110 =an14 01111 =an15 10000 =an16 10001 = reserved. no channel connected. ? ? ? 11100 = reserved. no channel connected. 11101 = temperature indicator (3) 11110 = dac output (1) 11111 = fvr (fixed voltage reference) buffer 1 output (2) bit 1 go/done : a/d conversion status bit 1 = a/d conversion cycle in progress. setting this bit starts an a/d conversion cycle. this bit is automatically cleared by hardware when the a/d conversion has completed. 0 = a/d conversion completed/not in progress bit 0 adon: adc enable bit 1 = adc is enabled 0 = adc is disabled and consumes no operating current note 1: see section 17.0 ?digital-to-analog converter (dac) module? for more information. 2: see section 14.0 ?fixed voltage reference (fvr)? for more information. 3: see section 15.0 ?temperature indicator module? for more information.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 167 pic16(l)f1946/1947 register 16-2: adcon1: a/ d control register 1 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 u-0 r/w-0/0 r/w-0/0 r/w-0/0 adfm adcs<2:0> ? adnref adpref<1:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 adfm: a/d result format select bit 1 = right justified. six most significant bits of adresh are set to ? 0 ? when the conversion result is loaded. 0 = left justified. six least significant bits of adresl are set to ? 0 ? when the conversion result is loaded. bit 6-4 adcs<2:0>: a/d conversion clock select bits 000 =f osc /2 001 =f osc /8 010 =f osc /32 011 =f rc (clock supplied from a dedicated rc oscillator) 100 =f osc /4 101 =f osc /16 110 =f osc /64 111 =f rc (clock supplied from a dedicated rc oscillator) bit 3 unimplemented: read as ? 0 ? bit 2 adnref: a/d negative voltage reference configuration bit 0 =v ref - is connected to v ss 1 =v ref - is connected to external v ref - bit 1-0 adpref<1:0>: a/d positive voltage reference configuration bits 00 =v ref + is connected to v dd 01 = reserved 10 =v ref + is connected to external v ref + (1) 11 =v ref + is connected to internal fixed voltage reference (fvr) module (1) note 1: when selecting the fvr or the v ref + pin as the source of the positive reference, be aware that a minimum voltage specification exists. see section 30.0 ?electrical specifications? for details.
pic16(l)f1946/1947 ds41414c-page 168 preliminary ? 2010-2011 microchip technology inc. register 16-3: adresh: adc result register high (adresh) adfm = 0 r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u adres<9:2> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 adres<9:2> : adc result register bits upper 8 bits of 10-bit conversion result register 16-4: adresl: adc result register low (adresl) adfm = 0 r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u adres<1:0> ? ? ? ? ? ? bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-6 adres<1:0> : adc result register bits lower 2 bits of 10-bit conversion result bit 5-0 reserved : do not use.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 169 pic16(l)f1946/1947 register 16-5: adresh: adc result register high (adresh) adfm = 1 r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u ? ? ? ? ? ? adres<9:8> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-2 reserved : do not use. bit 1-0 adres<9:8> : adc result register bits upper 2 bits of 10-bit conversion result register 16-6: adresl: adc result register low (adresl) adfm = 1 r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u adres<7:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 adres<7:0> : adc result register bits lower 8 bits of 10-bit conversion result
pic16(l)f1946/1947 ds41414c-page 170 preliminary ? 2010-2011 microchip technology inc. 16.5 a/d acquisition requirements for the adc to meet its specified accuracy, the charge holding capacitor (c hold ) must be allowed to fully charge to the input channel voltage level. the analog input model is shown in figure 16-4 . 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 ), refer to figure 16-4 . the maximum recommended impedance for analog sources is 10 k ? . as the source impedance is decreased, the acquisition time may be decreased. after the analog input channel is selected (or changed), an a/d acquisition must be done before the conversion can be started. to calculate the minimum acquisition time, equation 16-1 may be used. this equation assumes that 1/2 lsb error is used (1,024 steps for the adc). the 1/2 lsb error is the maximum error allowed for the adc to meet its specified resolution. equation 16-1: acquisition time example t acq amplifier settling time hold capacitor charging time temperature coefficient ++ = t amp t c t coff ++ = 2s t c temperature - 25c ?? 0.05s/c ?? ?? ++ = t c c hold r ic r ss r s ++ ?? ln(1/2047) ? = v applied 1e tc ? rc --------- ? ?? ?? ?? v applied 1 1 2 n1 + ?? 1 ? -------------------------- ? ?? ?? = v applied 1 1 2 n1 + ?? 1 ? -------------------------- ? ?? ?? v chold = v applied 1e t c ? rc --------- - ? ?? ?? ?? v chold = ;[1] v chold charged to within 1/2 lsb ;[2] v chold charge response to v applied ;combining [1] and [2] the value for t c can be approximated with the following equations: solving for t c : therefore: temperature 50c and external impedance of 10k ? 5.0v v dd = assumptions: note: where n = number of bits of the adc. t acq 2s 1.37s 50c- 25c ?? 0.05 s/c ?? ?? ++ = 4.62s = 10 pf 1 k ? 7 k ? 10 k ? ++ ?? 4.88 10 4 ? ? ?? ln ? = 1.37 s =
? 2010-2011 microchip technology inc. preliminary ds41414c-page 171 pic16(l)f1946/1947 figure 16-4: analog input model figure 16-5: adc transfer function note 1: the reference voltage (v ref ) has no effect on the equation, since it cancels itself out. 2: the charge holding capacitor (c hold ) is not discharged after each conversion. 3: the maximum recommended impedance for analog sources is 10 k ? . this is required to meet the pin leakage specification. c pin va rs analog 5 pf v dd v t ? 0.6v v t ? 0.6v i leakage (1) r ic ? 1k sampling switch ss rss c hold = 10 pf v ss /v ref - 6v sampling switch 5v 4v 3v 2v 567891011 (k ? ) v dd legend: c pin v t i leakage r ic ss c hold = input capacitance = threshold voltage = leakage current at the pin due to = interconnect resistance = sampling switch = sample/hold capacitance various junctions r ss note 1: refer to section 30.0 ?electrical specifications? . r ss = resistance of sampling switch input pin 3ffh 3feh adc output code 3fdh 3fch 03h 02h 01h 00h full-scale 3fbh 0.5 lsb v ref - zero-scale transition v ref + transition 1.5 lsb full-scale range analog input voltage
pic16(l)f1946/1947 ds41414c-page 172 preliminary ? 2010-2011 microchip technology inc. table 16-3: summary of registers associated with adc name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page adcon0 ? chs<4:0> go/done adon 166 adcon1 adfm adcs<2:0> ? adnref adpref<1:0> 167 adresh a/d result register high 168 adresl a/d result register low 168 ansela ? ?ansa5 ? ansa3 ansa2 ansa1 ansa0 129 anself anself7 anself6 anself5 anself4 anself3 anself2 anself1 anself0 145 anselg ? ? ? anselg4 anselg3 anselg2 anselg1 ? 148 ccp1con p1m<1:0> dc1b<1:0> ccp1m<3:0> 236 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 trisa trisa7 trisa6 trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 128 trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 131 trise trise7 trise6 trise5 trise4 trise3 trise2 trise1 trise0 140 fvrcon fvren fvrrdy tsen tsrng cdafvr<1:0> adfvr<1:0> 156 daccon0 dacen daclps dacoe ? dacpss<1:0> ? dacnss 176 daccon1 ? ? ? dacr<4:0> 176 legend: x = unknown, u = unchanged, ? = unimplemented read as ? 0 ?, q = value depends on condition. shaded cells are not used for adc module.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 173 pic16(l)f1946/1947 17.0 digital-to-analog converter (dac) module the digital-to-analog converter supplies a variable voltage reference, ratiometric with the input source, with 32 selectable output levels. the input of the dac can be connected to: ?external v ref pins ?v dd supply voltage ? fvr (fixed voltage reference) the output of the dac can be configured to supply a reference voltage to the following: ? comparator positive input ? adc input channel ?dacout pin the digital-to-analog converter (dac) can be enabled by setting the dacen bit of the daccon0 register. 17.1 output voltage selection the dac has 32 voltage level ranges. the 32 levels are set with the dacr<4:0> bits of the daccon1 register. the dac output voltage is determined by the following equations: equation 17-1: dac output voltage 17.2 ratiometric output level the dac output value is derived using a resistor ladder with each end of the ladder tied to a positive and negative voltage reference input source. if the voltage of either input source fluctuates, a similar fluctuation will result in the dac output value. the value of the individual resistors within the ladder can be found in section 30.0 ?electrical specifications? . 17.3 dac voltage reference output the dac can be output to the dacout pin by setting the dacoe bit of the daccon0 register to ? 1 ?. selecting the dac reference voltage for output on the dacout pin automatically overrides the digital output buffer and digital input threshold detector functions of that pin. reading the dacout pin when it has been configured for dac reference voltage output will always return a ? 0 ?. due to the limited current drive capability, a buffer must be used on the dac voltage reference output for external connections to dacout. figure 17-2 shows an example buffering technique. if dacen = 1 if dacen = 0 & daclps = 1 & dacr[4:0] = 11111 v out v source + = if dacen = 0 & daclps = 0 & dacr[4:0] = 00000 v out v source ? = v source + = v dd , v ref , or fvr buffer 2 v source - = v ss v out v source +v source - ? ?? dacr 4:0 ?? 2 5 ----------------------------- ? ?? ?? v source - + =
pic16(l)f1946/1947 ds41414c-page 174 preliminary ? 2010-2011 microchip technology inc. figure 17-1: digital-to-analog co nverter block diagram figure 17-2: voltage reference ou tput buffer example 32-to-1 mux dacr<4:0> r v ref - dacnss r r r r r r 32 dac dacout 5 (to comparator and adc modules) dacoe v dd v ref + dacpss<1:0> 2 dacen steps digital-to-analog converter (dac) fvr buffer2 r v source - v source + v ss daclps dacout buffered dac output + ? dac module voltage reference output impedance r pic ? mcu
? 2010-2011 microchip technology inc. preliminary ds41414c-page 175 pic16(l)f1946/1947 17.4 low-power voltage state in order for the dac module to consume the least amount of power, one of the two voltage reference input sources to the resistor ladder must be disconnected. either the positive voltage source, (v source +), or the negative voltage source, (v source -) can be disabled. the negative voltage source is disabled by setting the daclps bit in the daccon0 register. clearing the daclps bit in the daccon0 register disables the positive voltage source. 17.4.1 output clamped to positive voltage source the dac output voltage can be set to v source + with the least amount of power consumption by performing the following: ? clearing the dacen bit in the daccon0 register. ? setting the daclps bit in the daccon0 register. ? configuring the dacpss bits to the proper positive source. ? configuring the dacr<4:0> bits to ? 11111 ? in the daccon1 register. this is also the method used to output the voltage level from the fvr to an output pin. see section 17.5 ?operation during sleep? for more information. reference figure 17-3 for output clamping examples. 17.4.2 output clamped to negative voltage source the dac output voltage can be set to v source - with the least amount of power consumption by performing the following: ? clearing the dacen bit in the daccon0 register. ? clearing the daclps bit in the daccon0 register. ? configuring the dacnss bits to the proper negative source. ? configuring the dacr<4:0> bits to ? 00000 ? in the daccon1 register. this allows the comparator to detect a zero-crossing while not consuming additional current through the dac module. reference figure 17-3 for output clamping examples. figure 17-3: output volt age clamping examples 17.5 operation during sleep when the device wakes up from sleep through an interrupt or a watchdog timer time-out, the contents of the daccon0 register are not affected. to minimize current consumption in sleep mode, the voltage reference should be disabled. 17.6 effects of a reset a device reset affects the following: ? dac is disabled. ? dac output voltage is removed from the dacout pin. ? the dacr<4:0> range select bits are cleared. r r r dac voltage ladder (see figure 17-1 ) v source + dacen = 0 daclps = 1 dacr<4:0> = 11111 v source - r r r dac voltage ladder (see figure 17-1 ) v source + dacen = 0 daclps = 0 dacr<4:0> = 00000 v source - output clamped to positive voltage source output clamped to negative voltage source
pic16(l)f1946/1947 ds41414c-page 176 preliminary ? 2010-2011 microchip technology inc. 17.7 voltage reference control registers table 17-1: summary of registers asso ciated with the dac module register 17-1: daccon0: voltage re ference control register 0 r/w-0/0 r/w-0/0 r/w-0/0 u-0 r/w-0/0 r/w-0/0 u-0 r/w-0/0 dacen daclps dacoe ? dacpss<1:0> ? dacnss bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = val ue at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 dacen: dac enable bit 1 = dac is enabled 0 = dac is disabled bit 6 daclps: dac low-power voltage state select bit 1 = dac positive reference source selected 0 = dac negative reference source selected bit 5 dacoe: dac voltage output enable bit 1 = dac voltage level is also an output on the dacout pin 0 = dac voltage level is disconnected from the dacout pin bit 4 unimplemented: read as ? 0 ? bit 3-2 dacpss<1:0>: dac positive source select bits 00 =v dd 01 =v ref + pin 10 = fvr buffer2 output 11 = reserved, do not use bit 1 unimplemented: read as ? 0 ? bit 0 dacnss: dac negative source select bits 1 =v ref - 0 =v ss register 17-2: daccon1: voltage re ference control register 1 u-0 u-0 u-0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 ? ? ? dacr<4:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = val ue at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-5 unimplemented: read as ? 0 ? bit 4-0 dacr<4:0>: dac voltage output select bits name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page fvrcon fvren fvrrdy tsen tsrng cdafvr<1:0> adfvr1 adfvr0 156 daccon0 dacen daclps dacoe ? dacpss<1:0> ? dacnss 176 daccon1 ? ? ? dacr<4:0> 176 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used with the dac module.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 177 pic16(l)f1946/1947 18.0 comparator module comparators are used to interface analog circuits to a digital circuit by comparing two analog voltages and providing a digital indication of their relative magnitudes. comparators are very useful mixed signal building blocks because they provide analog functionality independent of program execution. the analog comparator module includes the following features: ? independent comparator control ? programmable input selection ? comparator output is available internally/externally ? programmable output polarity ? interrupt-on-change ? wake-up from sleep ? programmable speed/power optimization ?pwm shutdown ? programmable and fixed voltage reference 18.1 comparator overview a single comparator is shown in figure 18-1 along with the relationship between the analog input levels and the digital output. when the analog voltage at v in + is less than the analog voltage at v in -, the output of the comparator is a digital low level. when the analog voltage at v in + is greater than the analog voltage at v in -, the output of the comparator is a digital high level. figure 18-1: single comparator ? + v in + v in - output output v in + v in - note: the black areas of the output of the comparator represents the uncertainty due to input offsets and response time.
pic16(l)f1946/1947 ds41414c-page 178 preliminary ? 2010-2011 microchip technology inc. figure 18-2: comparator module simplified block diagram note 1: when cxon = 0 , the comparator will produce a ? 0 ? at the output. 2: when cxon = 0 , all multiplexer inputs are disconnected. 3: output of comparator can be frozen during debugging. mux cx (3) 0 1 2 3 cxon (1) cxnch<1:0> 2 0 1 c x pch<1:0> c x in1- c x in2- c x in3- c x in+ mux - + cxvn cxvp c x out to eccp pwm logic q1 d en q c x pol mc x out set cxif 0 1 c x sync c x oe c x out dq syncc x out dac fvr buffer2 c x in0- 2 cxsp cxhys det interrupt det interrupt to timer1 or sr latch cxintn cxintp to d a ta b u s 2 3 v ss tris bit cxon (2) (2) (from timer1) t1clk
? 2010-2011 microchip technology inc. preliminary ds41414c-page 179 pic16(l)f1946/1947 18.2 comparator control each comparator has 2 control registers: cmxcon0 and cmxcon1. the cmxcon0 registers (see register 18-1 ) contain control and status bits for the following: ? enable ?output selection ? output polarity ? speed/power selection ? hysteresis enable ? output synchronization the cmxcon1 registers (see register 18-2 ) contain control bits for the following: ? interrupt enable ? interrupt edge polarity ? positive input channel selection ? negative input channel selection 18.2.1 comparator enable setting the cxon bit of the cmxcon0 register enables the comparator for operation. clearing the cxon bit disables the comparator resulting in minimum current consumption. 18.2.2 comparator output selection the output of the comparator can be monitored by reading either the cxout bit of the cmxcon0 register or the mcxout bit of the cmout register. in order to make the output available for an external connection, the following conditions must be true: ? cxoe bit of the cmxcon0 register must be set ? corresponding tris bit must be cleared ? cxon bit of the cmxcon0 register must be set 18.2.3 comparator output polarity inverting the output of the comparator is functionally equivalent to swapping the comparator inputs. the polarity of the comparator output can be inverted by setting the cxpol bit of the cmxcon0 register. clearing the cxpol bit results in a non-inverted output. table 18-1 shows the output state versus input conditions, including polarity control. 18.2.4 comparator speed/power selection the trade-off between speed or power can be opti- mized during program execution with the cxsp control bit. the default state for this bit is ? 1 ? which selects the normal speed mode. device power consumption can be optimized at the cost of slower comparator propaga- tion delay by clearing the cxsp bit to ? 0 ?. note 1: the cxoe bit of the cmxcon0 register overrides the port data latch. setting the cxon bit of the cmxcon0 register has no impact on the port override. 2: the internal output of the comparator is latched with each instruction cycle. unless otherwise specified, external outputs are not latched. table 18-1: comparator output state vs. input conditions input condition cxpol cxout cxv n > cxv p 00 cxv n < cxv p 01 cxv n > cxv p 11 cxv n < cxv p 10
pic16(l)f1946/1947 ds41414c-page 180 preliminary ? 2010-2011 microchip technology inc. 18.3 comparator hysteresis a selectable amount of separation voltage can be added to the input pins of each comparator to provide a hysteresis function to the overall operation. hysteresis is enabled by setting the cxhys bit of the cm2con1 register. see section 30.0 ?electrical specifications? for more information. 18.4 timer1 gate operation the output resulting from a comparator operation can be used as a source for gate control of timer1. see section 21.6 ?timer1 gate? for more information. this feature is useful for timing the duration or interval of an analog event. it is recommended that the comparator output be syn- chronized to timer1. this ensures that timer1 does not increment while a change in the comparator is occur- ring. 18.4.1 comparator output synchronization the output from a comparator can be synchronized with timer1 by setting the cxsync bit of the cmxcon0 register. once enabled, the comparator output is latched on the falling edge of the timer1 source clock. if a prescaler is used with timer1, the comparator output is latched after the prescaling function. to prevent a race condition, the comparator output is latched on the falling edge of the timer1 clock source and timer1 increments on the rising edge of its clock source. see the comparator block diagram ( figure 18-2 ) and the timer1 block diagram ( figure 21-1 ) for more information. 18.5 comparator interrupt an interrupt can be generated upon a change in the output value of the comparator for each comparator, a rising edge detector and a falling edge detector are present. when either edge detector is triggered and its associ- ated enable bit is set (cxintp and/or cxintn bits of the cmxcon1 register), the corresponding interrupt flag bit (cxif bit of the pir2 register) will be set. to enable the interrupt, you must set the following bits: ? cxon, cxpol and cxsp bits of the cmxcon0 register ? cxie bit of the pie2 register ? cxintp bit of the cmxcon1 register (for a rising edge detection) ? cxintn bit of the cmxcon1 register (for a falling edge detection) ? peie and gie bits of the intcon register the associated interrupt flag bit, cxif bit of the pir2 register, must be cleared in software. if another edge is detected while this flag is being cleared, the flag will still be set at the end of the sequence. 18.6 comparator positive input selection configuring the cxpch<1:0> bits of the cmxcon1 register directs an internal voltage reference or an analog pin to the non-inverting input of the comparator: ? cxin+ analog pin ?dac ? fvr (fixed voltage reference) ?v ss (ground) see section 14.0 ?fixed voltage reference (fvr)? for more information on the fixed voltage reference module. see section 17.0 ?digital-to-analog converter (dac) module? for more information on the dac input signal. any time the comparator is disabled (cxon = 0 ), all comparator inputs are disabled. note: although a comparator is disabled, an interrupt can be generated by changing the output polarity with the cxpol bit of the cmxcon0 register, or by switching the comparator on or off with the cxon bit of the cmxcon0 register.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 181 pic16(l)f1946/1947 18.7 comparator negative input selection the cxnch<1:0> bits of the cmxcon0 register direct one of four analog pins to the comparator inverting input. 18.8 comparator response time the comparator output is indeterminate for a period of time after the change of an input source or the selection of a new reference voltage. this period is referred to as the response time. the response time of the comparator differs from the settling time of the voltage reference. therefore, both of these times must be considered when determining the total response time to a comparator input change. see the comparator and voltage refer- ence specifications in section 30.0 ?electrical speci- fications? for more details. 18.9 interaction with eccp logic the comparators can be used as general purpose comparators. their outputs can be brought out to the cxout pins. when the eccp auto-shutdown is active it can use one or both comparator signals. if auto-restart is also enabled, the comparators can be configured as a closed loop analog feedback to the eccp, thereby, creating an analog controlled pwm. 18.10 analog input connection considerations a simplified circuit for an analog input is shown in figure 18-3 . since the analog input pins share their connection with a digital input, they have reverse biased esd protection 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 for- ward biased and a latch-up may occur. a maximum source impedance of 10 k ? is recommended for the analog sources. also, any external component connected to an analog input pin, such as a capacitor or a zener diode, should have very little leakage current to minimize inaccuracies introduced. note: to use cxin+ and cxinx- pins as analog input, the appropriate bits must be set in the ansel register and the correspond- ing tris bits must also be set to disable the output drivers. note: when the comparator module is first initialized the output state is unknown. upon initialization, the user should verify the output state of the comparator prior to relying on the result, primarily when using the result in connection with other peripheral features, such as the eccp auto-shutdown mode. note 1: when reading a port register, all pins configured as analog inputs will read as a ? 0 ?. pins configured as digital inputs will convert as an analog input, according to the input specification. 2: analog levels on any pin defined as a digital input, may cause the input buffer to consume more current than is specified.
pic16(l)f1946/1947 ds41414c-page 182 preliminary ? 2010-2011 microchip technology inc. figure 18-3: analog input model v a rs < 10k c pin 5 pf v dd v t ? 0.6v v t ? 0.6v r ic i leakage (1) vss legend: c pin = input capacitance i leakage = leakage current at the pin due to various junctions r ic = interconnect resistance r s = source impedance v a = analog voltage v t = threshold voltage to comparator note 1: see section 30.0 ?electrical specifications? analog input pin
? 2010-2011 microchip technology inc. preliminary ds41414c-page 183 pic16(l)f1946/1947 18.11 comparator control registers register 18-1: cmxcon0: comparator cx control register 0 r/w-0/0 r-0/0 r/w-0/0 r/w-0/0 u-0 r/w-1/1 r/w-0/0 r/w-0/0 cxon cxout cxoe cxpol ? cxsp cxhys cxsync bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 cxon: comparator enable bit 1 = comparator is enabled and consumes no active power 0 = comparator is disabled bit 6 cxout: comparator output bit if cxpol = 1 (inverted polarity): 1 = cxvp < cxvn 0 = cxvp > cxvn if cxpol = 0 (non-inverted polarity): 1 = cxvp > cxvn 0 = cxvp < cxvn bit 5 cxoe: comparator output enable bit 1 = cxout is present on the cxout pin. requires that the associated tris bit be cleared to actually drive the pin. not affected by cxon. 0 = cxout is internal only bit 4 cxpol: comparator output polarity select bit 1 = comparator output is inverted 0 = comparator output is not inverted bit 3 unimplemented: read as ? 0 ? bit 2 cxsp: comparator speed/power select bit 1 = comparator operates in normal power, higher speed mode 0 = comparator operates in low-power, low-speed mode bit 1 cxhys: comparator hysteresis enable bit 1 = comparator hysteresis enabled 0 = comparator hysteresis disabled bit 0 cxsync: comparator output synchronous mode bit 1 = comparator output to timer1 and i/o pin is synchronous to changes on timer1 clock source. output updated on the falling edge of timer1 clock source. 0 = comparator output to timer1 and i/o pin is asynchronous.
pic16(l)f1946/1947 ds41414c-page 184 preliminary ? 2010-2011 microchip technology inc. register 18-2: cmxcon1: comparator cx control register 1 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 u-0 u-0 r/w-0/0 r/w-0/0 cxintp cxintn cxpch<1:0> ? ? cxnch<1:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 cxintp: comparator interrupt on positive going edge enable bits 1 = the cxif interrupt flag will be set upon a positive going edge of the cxout bit 0 = no interrupt flag will be set on a positive going edge of the cxout bit bit 6 cxintn: comparator interrupt on negative going edge enable bits 1 = the cxif interrupt flag will be set upon a negative going edge of the cxout bit 0 = no interrupt flag will be set on a negative going edge of the cxout bit bit 5-4 cxpch<1:0>: comparator positive input channel select bits 00 = cxvp connects to cxin+ pin 01 = cxvp connects to dac voltage reference 10 = cxvp connects to fvr voltage reference 11 = cxvp connects to v ss bit 3-2 unimplemented: read as ? 0 ? bit 1-0 cxnch<1:0>: comparator negative input channel select bits 00 = cxvn connects to c x in0- pin 01 = cxvn connects to c x in1- pin 10 = cxvn connects to c x in2- pin 11 = cxvn connects to c x in3- pin register 18-3: cmout: comparator output register u-0 u-0 u-0 u-0 u-0 r-0/0 r-0/0 r-0/0 ? ? ? ? ? mc3out mc2out mc1out bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-3 unimplemented: read as ? 0 ? bit 2 mc3out: mirror copy of c3out bit bit 1 mc2out: mirror copy of c2out bit bit 0 mc1out: mirror copy of c1out bit
? 2010-2011 microchip technology inc. preliminary ds41414c-page 185 pic16(l)f1946/1947 table 18-2: summary of registers as sociated with co mparator module name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page anself ansf7 ansf6 ansf5 ansf4 ansf3 ansf2 ansf1 ansf0 145 anselg ? ? ? ansg4 ansg3 ansg2 ansg1 ?148 cm1con0 c1on c1out c1oe c1pol ? c1sp c1hys c1sync 183 cm2con0 c2on c2out c2oe c2pol ? c2sp c2hys c2sync 183 cm1con1 c1ntp c1intn c1pch<1:0> ? ? c1nch<1:0> 184 cm2con1 c2ntp c2intn c2pch<1:0> ? ? c2nch<1:0> 184 cm3con0 c3on c3out c3oe c3pol ? c3sp c3hys c3sync 183 cm3con1 c3intp c3intn c3pch1 c3pch0 ? ? c3nch<1:0> 184 cmout ? ? ? ? ? mc3out mc2out mc1out 184 fvrcon fvren fvrrdy tsen tsrng cdafvr<1:0> adfvr<1:0> 156 daccon0 dacen daclps dacoe ? dacpss<1:0> ? dacnss 176 daccon1 ? ? ? dacr<4:0> 176 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie2 osfie c2ie c1ie eeie bclie lcdie c3ie ccp2ie 95 pir2 osfif c2if c1if eeif bclif lcdif c3if ccp2if 99 trisf trisf7 trisf6 trisf5 trisf4 trisf3 trisf2 trisf1 trisf0 144 trisg ? ? trisg5 trisg4 trisg3 trisg2 trisg1 trisg0 147 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are unused by the comparator module.
pic16(l)f1946/1947 ds41414c-page 186 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 187 pic16(l)f1946/1947 19.0 sr latch the module consists of a single sr latch with multiple set and reset inputs as well as separate latch outputs. the sr latch module includes the following features: ? programmable input selection ? sr latch output is available externally ? separate q and q outputs ? firmware set and reset the sr latch can be used in a variety of analog appli- cations, including oscillator circuits, one-shot circuit, hysteretic controllers, and analog timing applications. 19.1 latch operation the latch is a set-reset latch that does not depend on a clock source. each of the set and reset inputs are active-high. the latch can be set or reset by: ? software control (srps and srpr bits) ? comparator c1 output (syncc1out) ? comparator c2 output (syncc2out) ?sri pin ? programmable clock (srclk) the srps and the srpr bits of the srcon0 register may be used to set or reset the sr latch, respec- tively. the latch is reset-dominant. therefore, if both set and reset inputs are high, the latch will go to the reset state. both the srps and srpr bits are self resetting which means that a single write to either of the bits is all that is necessary to complete a latch set or reset operation. the output from comparator c1 or c2 can be used as the set or reset inputs of the sr latch. the output of either comparator can be synchronized to the timer1 clock source. see section 18.0 ?comparator mod- ule? and section 21.0 ?timer1 module with gate control? for more information. an external source on the sri pin can be used as the set or reset inputs of the sr latch. an internal clock source is available that can periodically set or reset the sr latch. the srclk<2:0> bits in the srcon0 register are used to select the clock source period. the srscke and srrcke bits of the srcon1 register enable the clock source to set or reset the sr latch, respectively. 19.2 latch output the srqen and srnqen bits of the srcon0 regis- ter control the q and q latch outputs. both of the sr latch outputs may be directly output to an i/o pin at the same time. the applicable tris bit of the corresponding port must be cleared to enable the port pin output driver. 19.3 effects of a reset upon any device reset, the sr latch output is not ini- tialized to a known state. the user?s firmware is responsible for initializing the latch output before enabling the output pins. note: enabling both the set and reset inputs from any one source at the same time may result in indeterminate operation, as the reset dominance cannot be assured.
pic16(l)f1946/1947 ds41414c-page 188 preliminary ? 2010-2011 microchip technology inc. figure 19-1: sr latch simplified block diagram srps s r q q note 1: if r = 1 and s = 1 simultaneously, q = 0 , q = 1 . 2: pulse generator causes a 1 q-state pulse width. 3: name denotes the connection point at the comparator output. pulse gen ( 2 ) sr latch (1) srqen srspe srsc2e srscke srclk syncc2out (3) srsc1e syncc1out (3) srpr pulse gen ( 2 ) srrpe srrc2e srrcke srclk syncc2out (3) srrc1e syncc1out (3) srlen srnqen srlen srq srnq sri sri
? 2010-2011 microchip technology inc. preliminary ds41414c-page 189 pic16(l)f1946/1947 table 19-1: srclk frequency table srclk divider f osc = 32 mhz f osc = 20 mhz f osc = 16 mhz f osc = 4 mhz f osc = 1 mhz 111 512 62.5 khz 39.0 khz 31.3 khz 7.81 khz 1.95 khz 110 256 125 khz 78.1 khz 62.5 khz 15.6 khz 3.90 khz 101 128 250 khz 156 khz 125 khz 31.25 khz 7.81 khz 100 64 500 khz 313 khz 250 khz 62.5 khz 15.6 khz 011 32 1 mhz 625 khz 500 khz 125 khz 31.3 khz 010 16 2 mhz 1.25 mhz 1 mhz 250 khz 62.5 khz 001 8 4 mhz 2.5 mhz 2 mhz 500 khz 125 khz 000 4 8 mhz 5 mhz 4 mhz 1 mhz 250 khz
pic16(l)f1946/1947 ds41414c-page 190 preliminary ? 2010-2011 microchip technology inc. 19.4 sr latch control registers register 19-1: srcon0: sr latch control 0 register r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/s-0/0 r/s-0/0 srlen srclk<2:0> srqen srnqen srps srpr bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared s = bit is set only bit 7 srlen: sr latch enable bit 1 = sr latch is enabled 0 = sr latch is disabled bit 6-4 srclk<2:0>: sr latch clock divider bits 000 = generates a 1 f osc wide pulse every 4th f osc cycle clock 001 = generates a 1 f osc wide pulse every 8th f osc cycle clock 010 = generates a 1 f osc wide pulse every 16th f osc cycle clock 011 = generates a 1 f osc wide pulse every 32nd f osc cycle clock 100 = generates a 1 f osc wide pulse every 64th f osc cycle clock 101 = generates a 1 f osc wide pulse every 128th f osc cycle clock 110 = generates a 1 f osc wide pulse every 256th f osc cycle clock 111 = generates a 1 f osc wide pulse every 512th f osc cycle clock bit 3 srqen: sr latch q output enable bit if srlen = 1 : 1 = q is present on the srq pin 0 = external q output is disabled if srlen = 0 : sr latch is disabled bit 2 srnqen: sr latch q output enable bit if srlen = 1 : 1 =q is present on the srnq pin 0 = external q output is disabled if srlen = 0 : sr latch is disabled bit 1 srps: pulse set input of the sr latch bit (1) 1 = pulse set input for 1 q-clock period 0 = no effect on set input bit 0 srpr: pulse reset input of the sr latch bit (1) 1 = pulse reset input for 1 q-clock period 0 = no effect on reset input note 1: set only, always reads back ? 0 ?.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 191 pic16(l)f1946/1947 table 19-2: summary of registers as sociated with sr latch module register 19-2: srcon1: sr latch control 1 register r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 srspe srscke srsc2e srsc1e srrpe srrcke srrc2e srrc1e bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 srspe: sr latch peripheral set enable bit 1 = sr latch is set when the sri pin is high 0 = sri pin has no effect on the set input of the sr latch bit 6 srscke: sr latch set clock enable bit 1 = set input of sr latch is pulsed with srclk 0 = srclk has no effect on the set input of the sr latch bit 5 srsc2e: sr latch c2 set enable bit 1 = sr latch is set when the c2 comparator output is high 0 = c2 comparator output has no effect on the set input of the sr latch bit 4 srsc1e: sr latch c1 set enable bit 1 = sr latch is set when the c1 comparator output is high 0 = c1 comparator output has no effect on the set input of the sr latch bit 3 srrpe: sr latch peripheral reset enable bit 1 = sr latch is reset when the sri pin is high 0 = sri pin has no effect on the reset input of the sr latch bit 2 srrcke: sr latch reset clock enable bit 1 = reset input of sr latch is pulsed with srclk 0 = srclk has no effect on the reset input of the sr latch bit 1 srrc2e: sr latch c2 reset enable bit 1 = sr latch is reset when the c2 comparator output is high 0 = c2 comparator output has no effect on the reset input of the sr latch bit 0 srrc1e: sr latch c1 reset enable bit 1 = sr latch is reset when the c1 comparator output is high 0 = c1 comparator output has no effect on the reset input of the sr latch name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page ansela ? ? ansa5 ? ansa3 ansa2 ansa1 ansa0 129 srcon0 srlen srclk<2:0> srqen srnqen srps srpr 190 srcon1 srspe srscke srsc2e srsc1e srrpe srrcke srrc2e srrc1e 191 trisa trisa7 trisa6 trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 128 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are unused by the sr latch module.
pic16(l)f1946/1947 ds41414c-page 192 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 193 pic16(l)f1946/1947 20.0 timer0 module the timer0 module is an 8-bit timer/counter with the following features: ? 8-bit timer/counter register (tmr0) ? 8-bit prescaler (independent of watchdog timer) ? programmable internal or external clock source ? programmable external clock edge selection ? interrupt on overflow ? tmr0 can be used to gate timer1 figure 20-1 is a block diagram of the timer0 module. 20.1 timer0 operation the timer0 module can be used as either an 8-bit timer or an 8-bit counter. 20.1.1 8-bit timer mode the timer0 module will increment every instruction cycle, if used without a prescaler. 8-bit timer mode is selected by clearing the tmr0cs bit of the option register. when tmr0 is written, the increment is inhibited for two instruction cycles immediately following the write. 20.1.2 8-bit counter mode in 8-bit counter mode, the timer0 module will increment on every rising or falling edge of the t0cki pin or the capacitive sensing oscillator (cpsclk) signal. 8-bit counter mode using the t0cki pin is selected by setting the tmr0cs bit in the option register to ? 1 ? and resetting the t0xcs bit in the cpscon0 register to ? 0 ?. 8-bit counter mode using the capacitive sensing oscillator (cpsclk) signal is selected by setting the tmr0cs bit in the option register to ? 1 ? and setting the t0xcs bit in the cpscon0 register to ? 1 ?. the rising or falling transition of the incrementing edge for either input source is determined by the tmr0se bit in the option register. figure 20-1: block diagra m of the timer0 note: the value written to the tmr0 register can be adjusted, in order to account for the two instruction cycle delay when tmr0 is written. t0cki tmr0se tmr0 ps<2:0> data bus set flag bit tmr0if on overflow tmr0cs 0 1 0 1 8 8 8-bit prescaler f osc /4 psa sync 2 t cy overflow to timer1 1 0 from cpsclk t0xcs
pic16(l)f1946/1947 ds41414c-page 194 preliminary ? 2010-2011 microchip technology inc. 20.1.3 software programmable prescaler a software programmable prescaler is available for exclusive use with timer0. the prescaler is enabled by clearing the psa bit of the option register. there are 8 prescaler options for the timer0 module ranging from 1:2 to 1:256. the prescale values are selectable via the ps<2:0> bits of the option register. in order to have a 1:1 prescaler value for the timer0 module, the prescaler must be disabled by setting the psa bit of the option register. the prescaler is not readable or writable. all instructions writing to the tmr0 register will clear the prescaler. 20.1.4 timer0 interrupt timer0 will generate an interrupt when the tmr0 register overflows from ffh to 00h. the tmr0if interrupt flag bit of the intcon register is set every time the tmr0 register overflows, regardless of whether or not the timer0 interrupt is enabled. the tmr0if bit can only be cleared in software. the timer0 interrupt enable is the tmr0ie bit of the intcon register. 20.1.5 8-bit counter mode synchronization when in 8-bit counter mode, the incrementing edge on the t0cki pin must be synchronized to the instruction clock. synchronization can be accomplished by sampling the prescaler output on the q2 and q4 cycles of the instruction clock. the high and low periods of the external clocking source must meet the timing requirements as shown in section 30.0 ?electrical specifications? . 20.1.6 operation during sleep timer0 cannot operate while the processor is in sleep mode. the contents of the tmr0 register will remain unchanged while the processor is in sleep mode. note: the watchdog timer (wdt) uses its own independent prescaler. note: the timer0 interrupt cannot wake the processor from sleep since the timer is frozen during sleep.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 195 pic16(l)f1946/1947 table 20-1: summary of registers associated with timer0 register 20-1: option_reg: option register r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 wpuen intedg tmr0cs tmr0se psa ps<2:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 wpuen : weak pull-up enable bit 1 = all weak pull-ups are disabled (except mclr , if it is enabled) 0 = weak pull-ups are enabled by individual wpux latch values bit 6 intedg: interrupt edge select bit 1 = interrupt on rising edge of rb0/int pin 0 = interrupt on falling edge of rb0/int pin bit 5 tmr0cs: timer0 clock source select bit 1 = transition on ra4/t0cki pin 0 = internal instruction cycle clock (f osc /4) bit 4 tmr0se: timer0 source edge select bit 1 = increment on high-to-low transition on ra4/t0cki pin 0 = increment on low-to-high transition on ra4/t0cki pin bit 3 psa: prescaler assignment bit 1 = prescaler is not assigned to the timer0 module 0 = prescaler is assigned to the timer0 module bit 2-0 ps<2:0>: prescaler rate select bits 000 001 010 011 100 101 110 111 1 : 2 1 : 4 1 : 8 1 : 16 1 : 32 1 : 64 1 : 128 1 : 256 bit value timer0 rate name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page cpscon0 cpson cpsrm ? ? cpsrng<1:0> cpsout t0xcs 332 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 option_reg wpuen intedg tmr0cs tmr0se psa ps<2:0> 195 tmr0 timer0 module register 193* trisa trisa7 trisa6 trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 128 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by the timer0 module. * page provides register information.
pic16(l)f1946/1947 ds41414c-page 196 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 197 pic16(l)f1946/1947 21.0 timer1 module with gate control the timer1 module is a 16-bit timer/counter with the following features: ? 16-bit timer/counter register pair (tmr1h:tmr1l) ? programmable internal or external clock source ? 2-bit prescaler ? dedicated 32 khz oscillator circuit ? optionally synchronized comparator out ? multiple timer1 gate (count enable) sources ? interrupt on overflow ? wake-up on overflow (external clock, asynchronous mode only) ? time base for the capture/compare function ? special event trigger (with ccp/eccp) ? selectable gate source polarity ? gate toggle mode ? gate single-pulse mode ? gate value status ? gate event interrupt figure 21-1 is a block diagram of the timer1 module. figure 21-1: timer1 block diagram tmr1h tmr1l t1sync t1ckps<1:0> prescaler 1, 2, 4, 8 0 1 synchronized clock input 2 set flag bit tmr1if on overflow tmr1 (2) tmr1on note 1: st buffer is high speed type when using t1cki. 2: timer1 register increments on rising edge. 3: synchronize does not operate while in sleep. t1g t1osc f osc /4 internal clock t1oso t1osi t1oscen 1 0 t1cki tmr1cs<1:0> (1) synchronize (3) det sleep input tmr1ge 0 1 00 01 10 11 t1gpol d q ck q 0 1 t1gval t1gtm single pulse acq. control t1gspm t1ggo/done t1gss<1:0> en out 10 11 00 01 f osc internal clock cap. sensing 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 oscillator from timer0 comparator 1 overflow comparator 2 syncc2out syncc1out to comparator module to lcd and clock switching modules
pic16(l)f1946/1947 ds41414c-page 198 preliminary ? 2010-2011 microchip technology inc. 21.1 timer1 operation the timer1 module is a 16-bit incrementing counter which is accessed through the tmr1h:tmr1l register pair. writes to tmr1h or tmr1l directly update the counter. 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 and incre- ments 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. table 21-1 displays the timer1 enable selections. 21.2 clock source selection the tmr1cs<1:0> and t1oscen bits of the t1con register are used to select the clock source for timer1. table 21-2 displays the clock source selections. 21.2.1 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. when the f osc internal clock source is selected, the timer1 register value will in crement by four counts every instruction clock cycle. due to this condition, a 2 lsb error in resolution will occur when reading the timer1 value. to utilize the full resolution of timer1, an asynchronous input signal must be used to gate the timer1 clock input. the following asynchronous sources may be used: ? asynchronous event on the t1g pin to timer1 gate ? c1 or c2 comparator input to timer1 gate 21.2.2 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 or the capacitive sensing oscillator signal. 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 21-1: timer1 enable selections tmr1on tmr1ge timer1 operation 00 off 01 off 10 always on 11 count enabled 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 ? write to tmr1h or tmr1l ? timer1 is disabled ? timer1 is disabled (tmr1on = 0 ) when t1cki is high then timer1 is enabled (tmr1on= 1 ) when t1cki is low. table 21-2: clock source selections tmr1cs1 tmr1cs0 t1oscen clock source 01x system clock (f osc ) 00x instruction clock (f osc /4) 11x capacitive sensing oscillator 100 external clocking on t1cki pin 101 osc.circuit on t1osi/t1oso pins
? 2010-2011 microchip technology inc. preliminary ds41414c-page 199 pic16(l)f1946/1947 21.3 timer1 prescaler timer1 has four prescaler options allowing 1, 2, 4 or 8 divisions of the clock input. the t1ckps bits of the t1con register control the prescale counter. the prescale counter is not directly readable or writable; however, the prescaler counter is cleared upon a write to tmr1h or tmr1l. 21.4 timer1 oscillator a dedicated low-power 32.768 khz oscillator circuit is built-in between pins t1osi (input) and t1oso (amplifier output). this internal circuit is to be used in conjunction with an external 32.768 khz crystal. the oscillator circuit is enabled by setting the t1oscen bit of the t1con register. the oscillator will continue to run during sleep. 21.5 timer1 operation in asynchronous counter mode if control bit t1sync of the t1con register is set, the external clock input is not synchronized. the timer increments asynchronously to the internal phase clocks. if the external clock source is selected then the timer will continue to run during sleep and can generate an interrupt on overflow, which will wake-up the processor. however, special precautions in software are needed to read/write the timer (see section 21.5.1 ?reading and writing timer1 in asynchronous counter mode? ). 21.5.1 reading and writing timer1 in asynchronous counter mode reading tmr1h or tmr1l while the timer is running from an external asynchronous clock will ensure a valid read (taken care of in hardware). however, the user should keep in mind that reading the 16-bit timer in two 8-bit values itself, poses certain problems, since the timer may overflow between the reads. for writes, it is recommended that the user simply stop the timer and write the desired values. a write contention may occur by writing to the timer registers, while the register is incrementing. this may produce an unpredictable value in the tmr1h:tmr1l register pair. 21.6 timer1 gate timer1 can be configured to count freely or the count can be enabled and disabled using timer1 gate circuitry. this is also referred to as timer1 gate enable. timer1 gate can also be driven by multiple selectable sources. 21.6.1 timer1 gate 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 of the t1gcon register. 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 21-3 for timing details. note: the oscillator requires a start-up and stabilization time before use. thus, t1oscen should be set and a suitable delay observed prior to using timer1. a suitable delay, similar to the ost delay can be implemented in software by clearing the tmr1if bit, then presetting the tmr1h:tmr1l register pair to fc00h. the tmr1if flag will be set when 1024 clock cycles have elapsed, thereby indicating that the oscillator is running and is reasonably stable. note: when switching from synchronous to asynchronous operation, it is possible to skip an increment. when switching from asynchronous to synchronous operation, it is possible to produce an additional increment. table 21-3: timer1 gate enable selections t1clk t1gpol t1g timer1 operation ? 00 counts ? 01 holds count ? 10 holds count ? 11 counts
pic16(l)f1946/1947 ds41414c-page 200 preliminary ? 2010-2011 microchip technology inc. 21.6.2 timer1 gate source selection the timer1 gate source can be selected from one of four different sources. source selection is controlled by the t1gss bits of the t1gcon register. the polarity for each available source is also selectable. polarity selection is controlled by the t1gpol bit of the t1gcon register. table 21-4: timer1 gate sources 21.6.2.1 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. 21.6.2.2 timer0 overflow gate operation when timer0 increments from ffh to 00h, a low-to-high pulse will automatically be generated and internally supplied to the timer1 gate circuitry. 21.6.2.3 comparator c1 gate operation the output resulting from a comparator 1 operation can be selected as a source for timer1 gate control. the comparator 1 output (syncc1out) can be synchronized to the timer1 clock or left asynchronous. for more information see section 18.4.1 ?comparator output synchronization? . 21.6.2.4 comparator c2 gate operation the output resulting from a comparator 2 operation can be selected as a source for timer1 gate control. the comparator 2 output (syncc2out) can be synchronized to the timer1 clock or left asynchronous. for more information see section 18.4.1 ?comparator output synchronization? . 21.6.3 timer1 gate toggle mode when timer1 gate toggle mode is enabled, it is possi- ble 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. see figure 21-4 for timing details. timer1 gate toggle mode is enabled by setting the t1gtm bit of the t1gcon register. when the t1gtm bit is cleared, the flip-flop is cleared and held clear. this is necessary in order to control which edge is measured. 21.6.4 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 first enabled by setting the t1gspm bit in the t1gcon register. next, the t1ggo/done bit in the t1gcon register must be set. the timer1 will be fully enabled on the next incrementing edge. on the next trailing edge of the pulse, the t1ggo/done bit will automatically be cleared. no other gate events will be allowed to increment timer1 until the t1ggo/done bit is once again set in software. see figure 21-5 for timing details. if the single pulse gate mode is disabled by clearing the t1gspm bit in the t1gcon register, the t1ggo/done bit should also be cleared. enabling the toggle mode and the single-pulse mode simultaneously will permit both sections to work together. this allows the cycle times on the timer1 gate source to be measured. see figure 21-6 for timing details. 21.6.5 timer1 gate value status when 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 in the t1gcon register. the t1gval bit is valid even when the timer1 gate is not enabled (tmr1ge bit is cleared). 21.6.6 timer1 gate event interrupt when timer1 gate event interrupt is enabled, it is pos- sible to generate an interrupt upon the completion of a gate event. when the falling edge of t1gval occurs, the tmr1gif flag bit in the pir1 register will be set. if the tmr1gie bit in the pie1 register is set, then an interrupt will be recognized. the tmr1gif flag bit operates even when the timer1 gate is not enabled (tmr1ge bit is cleared). t1gss timer1 gate source 00 timer1 gate pin 01 overflow of timer0 (tmr0 increments from ffh to 00h) 10 comparator 1 output syncc1out (optionally timer1 synchronized output) 11 comparator 2 output syncc2out (optionally timer1 synchronized output) note: enabling toggle mode at the same time as changing the gate polarity may result in indeterminate operation.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 201 pic16(l)f1946/1947 21.7 timer1 interrupt the timer1 register pair (tmr1h:tmr1l) increments to ffffh and rolls over to 0000h. when timer1 rolls over, the timer1 interrupt flag bit of the pir1 register is set. to enable the interrupt on rollover, you must set these bits: ? tmr1on bit of the t1con register ? tmr1ie bit of the pie1 register ? peie bit of the intcon register ? gie bit of the intcon register the interrupt is cleared by clearing the tmr1if bit in the interrupt service routine. 21.8 timer1 operation during sleep timer1 can only operate during sleep when setup in asynchronous counter mode. in this mode, an external crystal or clock source can be used to increment the counter. to set up the timer to wake the device: ? tmr1on bit of the t1con register must be set ? tmr1ie bit of the pie1 register must be set ? peie bit of the intcon register must be set ? t1sync bit of the t1con register must be set ? tmr1cs bits of the t1con register must be configured ? t1oscen bit of the t1con register must be configured the device will wake-up on an overflow and execute the next instructions. if the gie bit of the intcon register is set, the device will call the interrupt service routine. timer1 oscillator will continue to operate in sleep regardless of the t1sync bit setting. 21.9 eccp/ccp capture/compare time base the ccp modules use the tmr1h:tmr1l register pair as the time base when operating in capture or compare mode. in capture mode, the value in the tmr1h:tmr1l register pair is copied into the ccpr1h:ccpr1l register pair on a configured event. in compare mode, an event is triggered when the value ccpr1h:ccpr1l register pair matches the value in the tmr1h:tmr1l register pair. this event can be a special event trigger. for more information, see section 23.0 ?capture/compare/pwm modules? . 21.10 eccp/ccp special event trigger when any of the ccp?s are configured to trigger a spe- cial event, the trigger will clear the tmr1h:tmr1l reg- ister pair. this special event does not cause a timer1 interrupt. the ccp module may still be configured to generate a ccp interrupt. in this mode of operation, the ccpr1h:ccpr1l register pair becomes the period register for timer1. timer1 should be synchronized and f osc /4 should be selected as the clock source in order to utilize the spe- cial event trigger. asynchronous operation of timer1 can cause a special event trigger to be missed. in the event that a write to tmr1h or tmr1l coincides with a special event trigger from the ccp, the write will take precedence. for more information, see section 16.3.1 ?special event trigger? . figure 21-2: timer1 incrementing edge note: the tmr1h:tmr1l register pair and the tmr1if bit should be cleared before enabling interrupts. t1cki = 1 when tmr1 enabled t1cki = 0 when tmr1 enabled note 1: arrows indicate counter increments. 2: in counter mode, a falling edge must be registered by the count er prior to the first incrementing rising edge of the clock.
pic16(l)f1946/1947 ds41414c-page 202 preliminary ? 2010-2011 microchip technology inc. figure 21-3: timer1 gate enable mode figure 21-4: timer1 gate toggle mode tmr1ge t1gpol t1g_in t1cki t1gval timer1 n n + 1 n + 2 n + 3 n + 4 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
? 2010-2011 microchip technology inc. preliminary ds41414c-page 203 pic16(l)f1946/1947 figure 21-5: timer1 gate single-pulse mode tmr1ge t1gpol t1g_in t1cki t1gval timer1 n n + 1 n + 2 t1gspm t1ggo/ done 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 tmr1gif counting enabled on rising edge of t1g
pic16(l)f1946/1947 ds41414c-page 204 preliminary ? 2010-2011 microchip technology inc. figure 21-6: timer1 gate single-pulse and toggle combined mode tmr1ge t1gpol t1g_in t1cki t1gval timer1 nn + 1 n + 2 t1gspm t1ggo/ done 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 tmr1gif t1gtm counting enabled on rising edge of t1g n + 4 n + 3
? 2010-2011 microchip technology inc. preliminary ds41414c-page 205 pic16(l)f1946/1947 21.11 timer1 control register the timer1 control register (t1con), shown in register 21-1 , is used to control timer1 and select the various features of the timer1 module. register 21-1: t1con: ti mer1 control register r/w-0/u r/w-0/u r/w-0/u r/w-0/u r/w-0/u r/w-0/u u-0 r/w-0/u tmr1cs<1:0> t1ckps<1:0> t1oscen t1sync ?tmr1on bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-6 tmr1cs<1:0>: timer1 clock source select bits 11 = timer1 clock source is capacitive sensing oscillator (caposc) 10 = timer1 clock source is pin or oscillator: if t1oscen = 0 : external clock from t1cki pin (on the rising edge) if t1oscen = 1 : crystal oscillator on t1osi/t1oso pins 01 = timer1 clock source is system clock (f osc ) 00 = timer1 clock source is 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 t1oscen: lp oscillator enable control bit 1 = dedicated timer1 oscillator circuit enabled 0 = dedicated timer1 oscillator circuit disabled bit 2 t 1sync : timer1 external clock input synchronization control bit tmr1cs<1:0> = 1x 1 = do not synchronize external clock input 0 = synchronize external clock input with system clock (f osc ) tmr1cs<1:0> = 0x this bit is ignored. timer1 uses the internal clock when tmr1cs<1:0> = 1x . bit 1 unimplemented: read as ? 0 ? bit 0 tmr1on: timer1 on bit 1 = enables timer1 0 = stops timer1 clears timer1 gate flip-flop
pic16(l)f1946/1947 ds41414c-page 206 preliminary ? 2010-2011 microchip technology inc. 21.12 timer1 gate control register the timer1 gate control register (t1gcon), shown in register 21-2 , is used to control timer1 gate. register 21-2: t1gcon: timer1 gate control register r/w-0/u r/w-0/u r/w-0/u r/w-0/u r/w/hc-0/u r-x/x r/w-0/u r/w-0/u tmr1ge t1gpol t1gtm t1gspm t1ggo/ done t1gval t1gss<1:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared hc = bit is cleared by hardware 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/done : 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 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 1-0 t1gss<1:0>: timer1 gate source select bits 00 = timer1 gate pin 01 = timer0 overflow output 10 = comparator 1 optionally synchronized output (syncc1out) 11 = comparator 2 optionally synchronized output (syncc2out)
? 2010-2011 microchip technology inc. preliminary ds41414c-page 207 pic16(l)f1946/1947 table 21-5: summary of registers associated with timer1 name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page ccp1con p1m<1:0> dc1b<1:0> ccp1m<3:0> 236 ccp2con p2m<1:0> dc2b<1:0> ccp2m<3:0> 236 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 tmr1h holding register for the most significant byte of the 16-bit tmr1 register 201* tmr1l holding register for the least significant byte of the 16-bit tmr1 register 201* trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 131 trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 134 t1con tmr1cs<1:0> t1ckps<1:0> t1oscen t1sync ? tmr1on 205 t1gcon tmr1ge t1gpol t1gtm t1gspm t1ggo/ done t1gval t1gss<1:0> 206 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by the timer1 module. * page provides register information.
pic16(l)f1946/1947 ds41414c-page 208 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 209 pic16(l)f1946/1947 22.0 timer2/4/6 modules there are up to three identical timer2-type modules available. to maintain pre-existing naming conventions, the timers are called timer2, timer4 and timer6 (also timer2/4/6). the timer2/4/6 modules incorporate the following features: ? 8-bit timer and period registers (tmrx and prx, respectively) ? readable and writable (both registers) ? software programmable prescaler (1:1, 1:4, 1:16 and 1:64) ? software programmable postscaler (1:1 to 1:16) ? interrupt on tmrx match with prx, respectively ? optional use as the shift clock for the msspx modules (timer2 only) see figure 22-1 for a block diagram of timer2/4/6. figure 22-1: timer2/4/6 block diagram note: the ?x? variable used in this section is used to designate timer2, timer4, or timer6. for example, txcon references t2con, t4con or t6con. prx refer- ences pr2, pr4 or pr6. comparator tmrx sets flag tmrx output reset postscaler prescaler prx 2 f osc /4 1:1 to 1:16 1:1, 1:4, 1:16, 1:64 eq 4 bit tmrxif txoutps<3:0> txckps<1:0>
pic16(l)f1946/1947 ds41414c-page 210 preliminary ? 2010-2011 microchip technology inc. 22.1 timer2/4/6 operation the clock input to the timer2/4/6 modules is the system instruction clock (f osc /4). tmrx increments from 00h on each clock edge. a 4-bit counter/prescaler on the clock input allows direct input, divide-by-4 and divide-by-16 prescale options. these options are selected by the prescaler control bits, txckps<1:0> of the txcon register. the value of tmrx is compared to that of the period register, prx, 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 tmrx to 00h on the next cycle and drives the output counter/postscaler (see section 22.2 ?timer2/4/6 interrupt? ). the tmrx and prx registers are both directly readable and writable. the tmrx register is cleared on any device reset, whereas the prx register initializes to ffh. both the prescaler and postscaler counters are cleared on the following events: ? a write to the tmrx register ? a write to the txcon register ? power-on reset (por) ? brown-out reset (bor) ?mclr reset ? watchdog timer (wdt) reset ? stack overflow reset ? stack underflow reset ? reset instruction 22.2 timer2/4/6 interrupt timer2/4/6 can also generate an optional device interrupt. the timer2/4/6 output signal (tmrx-to-prx match) provides the input for the 4-bit counter/postscaler. this counter generates the tmrx match interrupt flag which is latched in tmrxif of the pirx register. the interrupt is enabled by setting the tmrx match interrupt enable bit, tmrxie of the piex register. a range of 16 postscale options (from 1:1 through 1:16 inclusive) can be selected with the postscaler control bits, txoutps<3:0>, of the txcon register. 22.3 timer2/4/6 output the unscaled output of tmrx is available primarily to the ccp modules, where it is used as a time base for operations in pwm mode. timer2 can be optionally used as the shift clock source for the msspx modules operating in spi mode. additional information is provided in section 24.0 ?master synchronous serial port (mssp1 and mssp2) module? . 22.4 timer2/4/6 operation during sleep the timer2/4/6 timers cannot be operated while the processor is in sleep mode. the contents of the tmrx and prx registers will remain unchanged while the processor is in sleep mode. note: tmrx is not cleared when txcon is written.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 211 pic16(l)f1946/1947 register 22-1: txcon: timer2/timer4/timer6 control register u-0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 ? txoutps<3:0> tmrxon txckps<1:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 unimplemented: read as ? 0 ? bit 6-3 txoutps<3:0>: timerx output postscaler select bits 0000 = 1:1 postscaler 0001 = 1:2 postscaler 0010 = 1:3 postscaler 0011 = 1:4 postscaler 0100 = 1:5 postscaler 0101 = 1:6 postscaler 0110 = 1:7 postscaler 0111 = 1:8 postscaler 1000 = 1:9 postscaler 1001 = 1:10 postscaler 1010 = 1:11 postscaler 1011 = 1:12 postscaler 1100 = 1:13 postscaler 1101 = 1:14 postscaler 1110 = 1:15 postscaler 1111 = 1:16 postscaler bit 2 tmrxon: timerx on bit 1 =timerx is on 0 =timerx is off bit 1-0 txckps<1:0>: timer2-type clock prescale select bits 00 = prescaler is 1 01 = prescaler is 4 10 = prescaler is 16 11 = prescaler is 64
pic16(l)f1946/1947 ds41414c-page 212 preliminary ? 2010-2011 microchip technology inc. table 22-1: summary of registers associated with timer2/4/6 name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page ccp2con p2m<1:0> dc2b<1:0> ccp2m<3:0> 236 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie3 ? ccp5ie ccp4ie ccp3ie tmr6ie ?tmr4ie ? 96 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir3 ? ccp5if ccp4if ccp3if tmr6if ?tmr4if ? 100 pr2 timer2 module period register 209* pr4 timer4 module period register 209* pr6 timer6 module period register 209* t2con ? t2outps<3:0> tmr2on t2ckps<1:0> 211 t4con ? t4outps<3:0> tmr4on t4ckps<1:0> 211 t6con ? t6outps<3:0> tmr6on t6ckps<1:0> 211 tmr2 holding register for the 8-bit tmr2 register 209* tmr4 holding register for the 8-bit tmr4 register (1) 209* tmr6 holding register for the 8-bit tmr6 register (1) 209* legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used for timer2 module. * page provides register information.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 213 pic16(l)f1946/1947 23.0 capture/compare/pwm modules the capture/compare/pwm module is a peripheral which allows the user to time and control different events, and to generate pulse-width modulation (pwm) signals. in capture mode, the peripheral allows the timing of the duration of an event. the compare mode allows the user to trigger an external event when a predetermined amount of time has expired. the pwm mode can generate pulse-width modulated signals of varying frequency and duty cycle. this family of devices contains three enhanced capture/compare/pwm modules (eccp1, eccp2, and eccp3) and two standard capture/compare/pwm modules (ccp4 and ccp5). the capture and compare functions are identical for all five ccp modules (eccp1, eccp2, eccp3, ccp4, and ccp5). the only differences between ccp modules are in the pulse-width modulation (pwm) function. the standard pwm function is identical in modules, ccp4 and ccp5. in ccp modules eccp1, eccp2, and eccp3, the enhanced pwm function has slight variations from one another. full-bridge eccp modules have four available i/o pins while half-bridge eccp modules only have two available i/o pins. see table 23-1 for more information. note 1: in devices with more than one ccp module, it is very important to pay close attention to the register names used. a number placed after the module acronym is used to distinguish between separate modules. for example, the ccp1con and ccp2con control the same operational aspects of two completely different ccp modules. 2: throughout this section, generic references to a ccp module in any of its operating modes may be interpreted as being equally applicable to eccp1, eccp2, eccp3, ccp4 and ccp5. register names, module signals, i/o pins, and bit names may use the generic designator 'x' to indicate the use of a numeral to distinguish a particular module, when required. table 23-1: pwm resources device name eccp1 eccp2 eccp3 ccp4 ccp5 pic16(l)f1946/1947 enhanced pwm full-bridge enhanced pwm full-bridge enhanced pwm full-bridge standard pwm standard pwm
pic16(l)f1946/1947 ds41414c-page 214 preliminary ? 2010-2011 microchip technology inc. 23.1 capture mode the capture mode function described in this section is available and identical for ccp modules eccp1, eccp2, eccp3, ccp4 and ccp5. capture mode makes use of the 16-bit timer1 resource. when an event occurs on the ccpx pin, the 16-bit ccprxh:ccprxl register pair captures and stores the 16-bit value of the tmr1h:tmr1l register pair, respectively. an event is defined as one of the following and is configured by the ccpxm<3:0> bits of the ccpxcon register: ? every falling edge ? every rising edge ? every 4th rising edge ? every 16th rising edge when a capture is made, the interrupt request flag bit ccpxif of the pirx register is set. the interrupt flag must be cleared in software. if another capture occurs before the value in the ccprxh, ccprxl register pair is read, the old captured value is overwritten by the new captured value. figure 23-1 shows a simplified diagram of the capture operation. 23.1.1 ccp pin configuration in capture mode, the ccpx pin should be configured as an input by setting the associated tris control bit. also, the ccpx pin function can be moved to alternative pins using the apfcon register. refer to section 12.1 ?alternate pin function? for more details. figure 23-1: capture mode operation block diagram 23.1.2 timer1 mode resource timer1 must be running in timer mode or synchronized counter mode for the ccp module to use the capture feature. in asynchronous counter mode, the capture operation may not work. see section 21.0 ?timer1 module with gate control? for more information on configuring timer1. 23.1.3 software interrupt mode when the capture mode is changed, a false capture interrupt may be generated. the user should keep the ccpxie interrupt enable bit of the piex register clear to avoid false interrupts. additionally, the user should clear the ccpxif interrupt flag bit of the pirx register following any change in operating mode. 23.1.4 ccp prescaler there are four prescaler settings specified by the ccpxm<3:0> bits of the ccpxcon register. whenever the ccp module is turned off, or the ccp module is not in capture mode, the prescaler counter is cleared. any reset will clear the prescaler counter. switching from one capture prescaler to another does not clear the prescaler and may generate a false interrupt. to avoid this unexpected operation, turn the module off by clearing the ccpxcon register before changing the prescaler. example 23-1 demonstrates the code to perform this function. example 23-1: changing between capture prescalers note: if the ccpx pin is configured as an output, a write to the port can cause a capture condition. ccprxh ccprxl tmr1h tmr1l set flag bit ccpxif (pirx register) capture enable ccpxm<3:0> prescaler ? 1, 4, 16 and edge detect pin ccpx system clock (f osc ) note: clocking timer1 from the system clock (f osc ) should not be used in capture mode. in order for capture mode to recognize the trigger event on the ccpx pin, timer1 must be clocked from the instruction clock (f osc /4) or from an external clock source. banksel ccpxcon ;set bank bits to point ;to ccpxcon clrf ccpxcon ;turn ccp module off movlw new_capt_ps ;load the w reg with ;the new prescaler ;move value and ccp on movwf ccpxcon ;load ccpxcon with this ;value
? 2010-2011 microchip technology inc. preliminary ds41414c-page 215 pic16(l)f1946/1947 23.1.5 capture during sleep capture mode depends upon the timer1 module for proper operation. there are two options for driving the timer1 module in capture mode. it can be driven by the instruction clock (f osc /4), or by an external clock source. when timer1 is clocked by f osc /4, timer1 will not increment during sleep. when the device wakes from sleep, timer1 will continue from its previous state. capture mode will operate during sleep when timer1 is clocked by an external clock source. 23.1.6 alternate pin locations this module incorporates i/o pins that can be moved to other locations with the use of the alternate pin function register, apfcon. to determine which pins can be moved and what their default locations are upon a reset, see section 12.1 ?alternate pin function? for more information. table 23-2: summary of registers associated with capture name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page ccpxcon pxm<1:0> (1) dcxb<1:0> ccpxm<3:0> 236 ccprxl capture/compare/pwm register x low byte (lsb) 214* ccprxh capture/compare/pwm register x high byte (msb) 214* intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie2 osfie c2ie c1ie eeie bclie lcdie c3ie ccp2ie 95 pie3 ? ccp5ie ccp4ie ccp3ie tmr6ie ? tmr4ie ? 96 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir2 osfif c2if c1if eeif bclif lcdif c3if ccp2if 99 pir3 ? ccp5if ccp4if ccp3if tmr6if ? tmr4if ? 100 t1con tmr1cs<1:0> t1ckps<1:0> t1oscen t1sync ?tmr1on 205 t1gcon tmr1ge t1gpol t1gtm t1gspm t1ggo/done t1gval t1gss<1:0> 206 tmr1l holding register for the least significant byte of the 16-bit tmr1 register 201* tmr1h holding register for the most significant byte of the 16-bit tmr1 register 201* trisa trisa7 trisa6 trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 128 trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 131 trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 134 trisd trisd7 trisd6 trisd5 trisd4 trisd3 trisd2 trisd1 trisd0 137 trise ? ? ? ? trise3 trise2 trise1 trise0 140 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by capture mode. note 1: applies to eccp modules only. * page provides register information.
pic16(l)f1946/1947 ds41414c-page 216 preliminary ? 2010-2011 microchip technology inc. 23.2 compare mode the compare mode function described in this section is available and identical for ccp modules eccp1, eccp2, eccp3, ccp4 and ccp5. compare mode makes use of the 16-bit timer1 resource. the 16-bit value of the ccprxh:ccprxl register pair is constantly compared against the 16-bit value of the tmr1h:tmr1l register pair. when a match occurs, one of the following events can occur: ? toggle the ccpx output ? set the ccpx output ? clear the ccpx output ? generate a special event trigger ? generate a software interrupt the action on the pin is based on the value of the ccpxm<3:0> control bits of the ccpxcon register. at the same time, the interrupt flag ccpxif bit is set. all compare modes can generate an interrupt. figure 23-2 shows a simplified diagram of the compare operation. figure 23-2: compare mode operation block diagram 23.2.1 ccp pin configuration the user must configure the ccpx pin as an output by clearing the associated tris bit. also, the ccpx pin function can be moved to alternative pins using the apfcon register. refer to section 12.1 ?alternate pin function? for more details. 23.2.2 timer1 mode resource in compare mode, timer1 must be running in either timer mode or synchronized counter mode. the compare operation may not work in asynchronous counter mode. see section 21.0 ?timer1 module with gate control? for more information on configuring timer1. 23.2.3 software interrupt mode when generate software interrupt mode is chosen (ccpxm<3:0> = 1010 ), the ccpx module does not assert control of the ccpx pin (see the ccpxcon register). 23.2.4 special event trigger when special event trigger mode is chosen (ccpxm<3:0> = 1011 ), the ccpx module does the following: ? resets timer1 ? starts an adc conversion if adc is enabled the ccpx module does not assert control of the ccpx pin in this mode. the special event trigger output of the ccp occurs immediately upon a match between the tmr1h, tmr1l register pair and the ccprxh, ccprxl regis- ter pair. the tmr1h, tmr1l register pair is not reset until the next rising edge of the timer1 clock. the spe- cial event trigger output starts an a/d conversion (if the a/d module is enabled). this allows the ccprxh, ccprxl register pair to effectively provide a 16-bit pro- grammable period register for timer1. refer to section 16.0 ?analog-to-digital converter (adc) module? for more information. note: clearing the ccpxcon register will force the ccpx compare output latch to the default low level. this is not the port i/o data latch. ccprxh ccprxl tmr1h tmr1l comparator qs r output logic special event trigger set ccpxif interrupt flag (pirx) match tris ccpxm<3:0> mode select output enable pin ccpx 4 note: clocking timer1 from the system clock (f osc ) should not be used in capture mode. in order for capture mode to recognize the trigger event on the ccpx pin, timer1 must be clocked from the instruction clock (f osc /4) or from an external clock source. table 23-3: special event trigger device ccpx/eccpx pic16f/lf1946/47 ccp5 note 1: the special event trigger from the ccp module does not set interrupt flag bit tmr1if of the pir1 register. 2: removing the match condition by changing the contents of the ccprxh and ccprxl register pair, between the clock edge that generates the special event trigger and the clock edge that generates the timer1 reset, will preclude the reset from occurring.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 217 pic16(l)f1946/1947 23.2.5 compare during sleep the compare mode is dependent upon the system clock (f osc ) for proper operation. since f osc is shut down during sleep mode, the compare mode will not function properly during sleep. 23.2.6 alternate pin locations this module incorporates i/o pins that can be moved to other locations with the use of the alternate pin function register, apfcon. to determine which pins can be moved and what their default locations are upon a reset, see section 12.1 ?alternate pin function? for more information. table 23-4: summary of regist ers associated with compare name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page ccpxcon pxm<1:0> (1) dcxb<1:0> ccpxm<3:0> 236 ccprxl capture/compare/pwm register x low byte (lsb) 214* ccprxh capture/compare/pwm register x high byte (msb) 214* intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie2 osfie c2ie c1ie eeie bclie lcdie c3ie ccp2ie 95 pie3 ? ccp5ie ccp4ie ccp3ie tmr6ie ? tmr4ie ? 96 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir2 osfif c2if c1if eeif bclif lcdif c31f ccp2if 99 pir3 ? ccp5if ccp4if ccp3if tmr6if ? tmr4if ? 100 t1con tmr1cs<1:0> t1ckps<1:0> t1oscen t1sync ?tmr1on 205 t1gcon tmr1ge t1gpol t1gtm t1gspm t1ggo/done t1gval t1gss<1:0> 206 tmr1l holding register for the least significant byte of the 16-bit tmr1 register 201* tmr1h holding register for the most significant byte of the 16-bit tmr1 register 201* trisa trisa7 trisa6 trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 128 trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 131 trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 134 trisd trisd7 trisd6 trisd5 trisd4 trisd3 trisd2 trisd1 trisd0 137 trise trise7 trise6 trise5 trise4 trise3 trise2 trise1 trise0 140 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by compare mode. note 1: applies to eccp modules only. * page provides register information.
pic16(l)f1946/1947 ds41414c-page 218 preliminary ? 2010-2011 microchip technology inc. 23.3 pwm overview pulse-width modulation (pwm) is a scheme that provides power to a load by switching quickly between fully on and fully off states. the pwm signal resembles a square wave where the high portion of the signal is considered the on state and the low portion of the signal is considered the off state. the high portion, also known as the pulse width, can vary in time and is defined in steps. a larger number of steps applied, which lengthens the pulse width, also supplies more power to the load. lowering the number of steps applied, which shortens the pulse width, supplies less power. the pwm period is defined as the duration of one complete cycle or the total amount of on and off time combined. pwm resolution defines the maximum number of steps that can be present in a single pwm period. a higher resolution allows for more precise control of the pulse width time and in turn the power that is applied to the load. the term duty cycle describes the proportion of the on time to the off time and is expressed in percentages, where 0% is fully off and 100% is fully on. a lower duty cycle corresponds to less power applied and a higher duty cycle corresponds to more power applied. figure 23-3 shows a typical waveform of the pwm signal. 23.3.1 standard pwm operation the standard pwm function described in this section is available and identical for ccp modules eccp1, eccp2, eccp3, ccp4 and ccp5. the standard pwm mode generates a pulse-width modulation (pwm) signal on the ccpx pin with up to 10 bits of resolution. the period, duty cycle, and resolution are controlled by the following registers: ?prx registers ?txcon registers ? ccprxl registers ? ccpxcon registers figure 23-4 shows a simplified block diagram of pwm operation. figure 23-3: ccp pwm output signal figure 23-4: simplified pwm block diagram note 1: the corresponding tris bit must be cleared to enable the pwm output on the ccpx pin. 2: clearing the ccpxcon register will relinquish control of the ccpx pin. period pulse width tmrx = 0 tmrx = ccprxh:ccpxcon<5:4> tmrx = prx ccprxl ccprxh (2) (slave) comparator tmrx prx (1) rq s duty cycle registers ccpxcon<5:4> clear timer, toggle ccpx pin and latch duty cycle note 1: the 8-bit timer tmrx register is concatenated with the 2-bit internal system clock (f osc ), or 2 bits of the prescaler, to create the 10-bit time base. 2: in pwm mode, ccprxh is a read-only register. tris ccpx comparator
? 2010-2011 microchip technology inc. preliminary ds41414c-page 219 pic16(l)f1946/1947 23.3.2 setup for pwm operation the following steps should be taken when configuring the ccp module for standard pwm operation: 1. disable the ccpx pin output driver by setting the associated tris bit. 2. load the prx register with the pwm period value. 3. configure the ccp module for the pwm mode by loading the ccpxcon register with the appropriate values. 4. load the ccprxl register and the dcxbx bits of the ccpxcon register, with the pwm duty cycle value. 5. configure and start timer2/4/6: ? select the timer2/4/6 resource to be used for pwm generation by setting the cxtsel<1:0> bits in the ccptmrsx register. ? clear the tmrxif interrupt flag bit of the pirx register. see note below. ? configure the txckps bits of the txcon register with the timer prescale value. ? enable the timer by setting the tmrxon bit of the txcon register. 6. enable pwm output pin: ? wait until the timer overflows and the tmrxif bit of the pirx register is set. see note below. ? enable the ccpx pin output driver by clear- ing the associated tris bit. 23.3.3 timer2/4/6 timer resource the pwm standard mode makes use of one of the 8-bit timer2/4/6 timer resources to specify the pwm period. configuring the cxtsel<1:0> bits in the ccptmrsx register selects which timer2/4/6 timer is used. 23.3.4 pwm period the pwm period is specified by the prx register of timer2/4/6. the pwm period can be calculated using the formula of equation 23-1 . equation 23-1: pwm period when tmrx is equal to prx, the following three events occur on the next increment cycle: ? tmrx is cleared ? the ccpx pin is set. (exception: if the pwm duty cycle = 0%, the pin will not be set.) ? the pwm duty cycle is latched from ccprxl into ccprxh. 23.3.5 pwm duty cycle the pwm duty cycle is specified by writing a 10-bit value to multiple registers: ccprxl register and dcxb<1:0> bits of the ccpxcon register. the ccprxl contains the eight msbs and the dcxb<1:0> bits of the ccpxcon register contain the two lsbs. ccprxl and dcxb<1:0> bits of the ccpxcon register can be written to at any time. the duty cycle value is not latched into ccprxh until after the period completes (i.e., a match between prx and tmrx registers occurs). while using the pwm, the ccprxh register is read-only. equation 23-2 is used to calculate the pwm pulse width. equation 23-3 is used to calculate the pwm duty cycle ratio. equation 23-2: pulse width equation 23-3: duty cycle ratio the ccprxh register and a 2-bit internal latch are used to double buffer the pwm duty cycle. this double buffering is essential for glitchless pwm operation. the 8-bit timer tmrx register is concatenated with either the 2-bit internal system clock (f osc ), or 2 bits of the prescaler, to create the 10-bit time base. the system clock is used if the timer2/4/6 prescaler is set to 1:1. when the 10-bit time base matches the ccprxh and 2-bit latch, then the ccpx pin is cleared (see figure 23-4 ). note: in order to send a complete duty cycle and period on the first pwm output, the above steps must be included in the setup sequence. if it is not critical to start with a complete pwm signal on the first output, then step 6 may be ignored. pwm period prx ?? 1 + ?? 4t osc ? ? ? = (tmrx prescale value) note 1: t osc = 1/f osc note: the timer postscaler (see section 22.1 ?timer2/4/6 operation? ) is not used in the determination of the pwm frequency. pulse width ccprxl:ccpxcon<5:4> ?? ? = t osc ? (tmrx prescale value) duty cycle ratio ccprxl:ccpxcon<5:4> ?? 4 prx 1 + ?? ---------------------------------------------------------------------- - =
pic16(l)f1946/1947 ds41414c-page 220 preliminary ? 2010-2011 microchip technology inc. 23.3.6 pwm resolution the resolution determines the number of available duty cycles for a given period. for example, a 10-bit resolution will result in 1024 discrete duty cycles, whereas an 8-bit resolution will result in 256 discrete duty cycles. the maximum pwm resolution is 10 bits when prx is 255. the resolution is a function of the prx register value as shown by equation 23-4 . equation 23-4: pwm resolution table 23-5: example pwm frequencies and resolutions (f osc = 32 mhz) table 23-6: example pwm frequencies and resolutions (f osc = 20 mhz) table 23-7: example pwm frequencies and resolutions (f osc = 8 mhz) note: if the pulse width value is greater than the period the assigned pwm pin(s) will remain unchanged. resolution 4prx 1 + ?? ?? log 2 ?? log ----------------------------------------- - bits = pwm frequency 1.95 khz 7.81 khz 31.25 khz 125 khz 250 khz 333.3 khz timer prescale (1, 4, 16) 16 4 1 1 1 1 prx value 0xff 0xff 0xff 0x3f 0x1f 0x17 maximum resolution (bits) 10 10 10 8 7 6.6 pwm frequency 1.22 khz 4.88 khz 19.53 khz 78.12 khz 156.3 khz 208.3 khz timer prescale (1, 4, 16) 16 4 1 1 1 1 prx value 0xff 0xff 0xff 0x3f 0x1f 0x17 maximum resolution (bits) 10 10 10 8 7 6.6 pwm frequency 1.22 khz 4.90 khz 19.61 khz 76.92 khz 153.85 khz 200.0 khz timer prescale (1, 4, 16) 16 4 1 1 1 1 prx value 0x65 0x65 0x65 0x19 0x0c 0x09 maximum resolution (bits) 8 8 8 6 5 5
? 2010-2011 microchip technology inc. preliminary ds41414c-page 221 pic16(l)f1946/1947 23.3.7 operation in sleep mode in sleep mode, the tmrx register will not increment and the state of the module will not change. if the ccpx pin is driving a value, it will continue to drive that value. when the device wakes up, tmrx will continue from its previous state. 23.3.8 changes in system clock frequency the pwm frequency is derived from the system clock frequency. any changes in the system clock frequency will result in changes to the pwm frequency. see section 5.0 ?oscillator module (with fail-safe clock monitor)? for additional details. 23.3.9 effects of reset any reset will force all ports to input mode and the ccp registers to their reset states. 23.3.10 alternate pin locations this module incorporates i/o pins that can be moved to other locations with the use of the alternate pin function register, apfcon. to determine which pins can be moved and what their default locations are upon a reset, see section 12.1 ?alternate pin function? for more information. table 23-8: summary of registers associated with standard pwm name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page ccpxcon pxm<1:0> (1) dcxb<1:0> ccpxm<3:0> 236 ccptmrs0 c4tsel<1:0> c3tsel<1:0> c2tsel<1:0> c1tsel<1:0> 237 ccptmrs1 ? ? ? ? ? ? c5tsel<1:0> 237 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie2 osfie c2ie c1ie eeie bclie lcdie c3ie ccp2ie 95 pie3 ? ccp5ie ccp4ie ccp3ie tmr6ie ? tmr4ie ? 96 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir2 osfif c2if c1if eeif bclif lcdif c3if ccp2if 99 pir3 ? ccp5if ccp4if ccp3if tmr6if ? tmr4if ? 100 prx timer2/4/6 period register 209* txcon ? txoutps<3:0> tmrxon txckps<:0>1 211 tmrx timer2/4/6 module register 209* trisa trisa7 trisa6 trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 128 trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 131 trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 134 trisd trisd7 trisd6 trisd5 trisd4 trisd3 trisd2 trisd1 trisd0 137 trise trise7 trise6 trise5 trise4 trise3 trise2 trise1 trise0 140 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by the pwm. note 1: applies to eccp modules only. * page provides register information.
pic16(l)f1946/1947 ds41414c-page 222 preliminary ? 2010-2011 microchip technology inc. 23.4 pwm (enhanced mode) the enhanced pwm function described in this section is available for ccp modules eccp1, eccp2 and eccp3, with any differences between modules noted. the enhanced pwm mode generates a pulse-width modulation (pwm) signal on up to four different output pins with up to 10 bits of resolution. the period, duty cycle, and resolution are controlled by the following registers: ?prx registers ?txcon registers ? ccprxl registers ? ccpxcon registers the eccp modules have the following additional pwm registers which control auto-shutdown, auto-restart, dead-band delay and pwm steering modes: ? ccpxas registers ? pstrxcon registers ? pwmxcon registers the enhanced pwm module can generate the following five pwm output modes: ? single pwm ? half-bridge pwm ? full-bridge pwm, forward mode ? full-bridge pwm, reverse mode ? single pwm with pwm steering mode to select an enhanced pwm output mode, the pxm bits of the ccpxcon register must be configured 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. figure 23-5 shows an example of a simplified block diagram of the enhanced pwm module. table 23-9 shows the pin assignments for various enhanced pwm modes. figure 23-5: example simplified block diagram of the enhanced pwm mode note 1: the corresponding tris bit must be cleared to enable the pwm output on the ccpx pin. 2: clearing the ccpxcon register will relinquish control of the ccpx pin. 3: any pin not used in the enhanced pwm mode is available for alternate pin functions, if applicable. 4: 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. ccprxl ccprxh (slave) comparator tmrx comparator prx (1) rq s duty cycle registers dcxb<1:0> clear timer, toggle pwm pin and latch duty cycle note 1: the 8-bit timer tmrx register is concatenated with the 2-bit internal q clock, or 2 bits of the prescaler to create the 10-bit time base. trisx ccpx/pxa trisx pxb trisx pxc trisx pxd output controller pxm<1:0> 2 ccpxm<3:0> 4 pwmxcon ccpx/pxa pxb pxc pxd
? 2010-2011 microchip technology inc. preliminary ds41414c-page 223 pic16(l)f1946/1947 table 23-9: example pin assignments for various pwm enhanced modes figure 23-6: example pwm (enhanced mode) output relationships (active-high state) eccp mode pxm<1:0> ccpx/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: pwm steering enables outputs in single mode. 0 period 00 10 01 11 signal prx+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 delay relationships: ? period = 4 * t osc * (prx + 1) * (tmrx prescale value) ? pulse width = t osc * (ccprxl<7:0>:ccpxcon<5:4>) * (tmrx prescale value) ? delay = 4 * t osc * (pwmxcon<6:0>)
pic16(l)f1946/1947 ds41414c-page 224 preliminary ? 2010-2011 microchip technology inc. figure 23-7: example enhanced pwm outp ut relationships (active-low state) 0 period 00 10 01 11 signal prx+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 delay relationships: ? period = 4 * t osc * (prx + 1) * (tmrx prescale value) ? pulse width = t osc * (ccprxl<7:0>:ccpxcon<5:4>) * (tmrx prescale value) ? delay = 4 * t osc * (pwmxcon<6:0>)
? 2010-2011 microchip technology inc. preliminary ds41414c-page 225 pic16(l)f1946/1947 23.4.1 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 ccpx/pxa pin, while the complementary pwm output signal is output on the pxb pin (see figure 23-9 ). this mode can be used for half-bridge applications, as shown in figure 23-9 , 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 pdc<6:0> bits of the pwmxcon 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. see section 23.4.5 ?programmable dead-band delay mode? for more details of the dead-band delay operations. 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 23-8: example of half-bridge pwm output figure 23-9: 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 tmrx register is equal to the prx register. 2: output signals are shown as active-high. pxa pxb fet driver fet driver load + - + - fet driver fet driver v+ load fet driver fet driver pxa pxb standard half-bridge circuit (?push-pull?) half-bridge output driving a full-bridge circuit
pic16(l)f1946/1947 ds41414c-page 226 preliminary ? 2010-2011 microchip technology inc. 23.4.2 full-bridge mode in full-bridge mode, all four pins are used as outputs. an example of full-bridge application is shown in figure 23-10 . in the forward mode, pin ccpx/pxa is driven to its active state, pin pxd is modulated, while pxb and pxc will be driven to their inactive state as shown in figure 23-11 . in the reverse mode, pxc is driven to its active state, pin pxb is modulated, while pxa and pxd will be driven to their inactive state as shown figure 23-11 . 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 23-10: example of full-bridge application pxa pxc fet driver fet driver v+ v- load fet driver fet driver pxb pxd qa qb qd qc
? 2010-2011 microchip technology inc. preliminary ds41414c-page 227 pic16(l)f1946/1947 figure 23-11: 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 tmrx register is equal to the prx register. 2: output signal is shown as active-high.
pic16(l)f1946/1947 ds41414c-page 228 preliminary ? 2010-2011 microchip technology inc. 23.4.2.1 direction change in full-bridge mode in the 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 four timer cycles 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. see figure 23-12 for an illustration of this sequence. the full-bridge mode does not provide dead-band delay. as one output is modulated at a time, dead-band delay is generally not required. there is a situation where dead-band delay is required. this situation occurs when both of the following conditions are true: 1. the direction of the pwm output changes when the duty cycle of the output is at or near 100%. 2. the turn off time of the power switch, including the power device and driver circuit, is greater than the turn on time. figure 23-13 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 output pxa and pxd become inactive, while output pxc 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 23-10 ) 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: 1. reduce pwm duty cycle for one pwm period before changing directions. 2. 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 23-12: 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 ti me. the length of this time is four timer counts. period (2) pxa (active-high) pxb (active-high) pxc (active-high) pxd (active-high) pulse width
? 2010-2011 microchip technology inc. preliminary ds41414c-page 229 pic16(l)f1946/1947 figure 23-13: example of pwm direct ion change at near 100% duty cycle forward period reverse period pxa t on t off t = t off ? t on 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 power switch qc and its driver. 3: t off is the turn off delay of pow er switch qd and its driver. external switch c t1 pw pw
pic16(l)f1946/1947 ds41414c-page 230 preliminary ? 2010-2011 microchip technology inc. 23.4.3 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 ccpxas<2:0> bits of the ccpxas register. a shutdown event may be generated by: ?a logic ? 0 ? on the int pin ?a logic ? 1 ? on a comparator (cx) output a shutdown condition is indicated by the ccpxase (auto-shutdown event status) bit of the ccpxas register. 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. when a shutdown event occurs, two things happen: the ccpxase bit is set to ? 1 ?. the ccpxase will remain set until cleared in firmware or an auto-restart occurs (see section 23.4.4 ?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 of the ccpxas register. each pin pair may be placed into one of three states: ?drive logic ? 1 ? ?drive logic ? 0 ? ? tri-state (high-impedance) 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 ccpxase bit of the ccpxas register 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. 4: prior to an auto-shutdown event caused by a comparator output or int pin event, a software shutdown can be triggered in firmware by setting the ccpxase bit of the ccpxas register to ? 1 ?. the auto-restart feature tracks the active status of a shutdown caused by a comparator output or int pin event only. if it is enabled at this time, it will immediately clear this bit and restart the eccp module at the beginning of the next pwm period.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 231 pic16(l)f1946/1947 figure 23-14: pwm auto-shutdown wi th firmware restart (pxrsen = 0 ) 23.4.4 auto-restart mode the enhanced pwm can be configured to automati- cally restart the pwm signal once the auto-shutdown condition has been removed. auto-restart is enabled by setting the pxrsen bit in the pwmxcon register. if auto-restart is enabled, the ccpxase bit will remain set as long as the auto-shutdown condition is active. when the auto-shutdown condition is removed, the ccpxase bit will be cleared via hardware and normal operation will resume. figure 23-15: pwm auto-shutdown with auto-restart (pxrsen = 1 ) shutdown pwm ccpxase bit activity event shutdown event occurs shutdown event clears pwm resumes pwm period start of pwm period ccpxase cleared by firmware timer overflow timer overflow timer overflow timer overflow missing pulse (auto-shutdown) missing pulse (ccpxase not clear) timer overflow shutdown pwm ccpxase bit activity event shutdown event occurs shutdown event clears pwm period start of pwm period ccpxase cleared by hardware timer overflow timer overflow timer overflow timer overflow missing pulse (auto-shutdown) missing pulse (ccpxase not clear) timer overflow pwm resumes
pic16(l)f1946/1947 ds41414c-page 232 preliminary ? 2010-2011 microchip technology inc. 23.4.5 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 of time 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. see figure 23-16 for illustration. the lower seven bits of the associated pwmxcon register ( register 23-5 ) sets the delay period in terms of microcontroller instruction cycles (t cy or 4 t osc ). figure 23-16: example of half-bridge pwm output figure 23-17: 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 tmrx register is equal to the prx 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?)
? 2010-2011 microchip technology inc. preliminary ds41414c-page 233 pic16(l)f1946/1947 23.4.6 pwm steering mode in single output mode, pwm steering allows any of the pwm pins to be the modulated signal. additionally, the same pwm signal can be simultaneously 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 strx bits of the pstrxcon register, as shown in ta b l e 2 3 - 9 . while the pwm steering mode is active, ccpxm<1:0> bits of the ccpxcon register select the pwm output polarity for the px pins. the pwm auto-shutdown operation also applies to pwm steering mode as described in section 23.4.3 ?enhanced pwm auto-shutdown mode? . an auto-shutdown event will only affect pins that have pwm outputs enabled. figure 23-18: simplified steering block diagram 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. 1 0 tris pxa pin port data pxa signal strxa 1 0 tris pxb pin port data strxb 1 0 tris pxc pin port data strxc 1 0 tris pxd pin port data strxd note 1: port outputs are configured as shown when the ccpxcon register bits pxm<1:0> = 00 and ccpxm<3:2> = 11. 2: single pwm output requires setting at least one of the strx bits. ccpxm1 ccpxm0 ccpxm1 ccpxm0
pic16(l)f1946/1947 ds41414c-page 234 preliminary ? 2010-2011 microchip technology inc. 23.4.6.1 steering synchronization the strxsync bit of the pstrxcon register gives the user two selections of when the steering event will happen. when the strxsync bit is ? 0 ?, the steering event will happen at the end of the instruction that writes to the pstrxcon register. in this case, the output 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 strxsync 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 23-19 and 23-20 illustrate the timing diagrams of the pwm steering depending on the strxsync setting. 23.4.7 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 configuration while the pwm pin output drivers are enable 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 tmrxif bit of the pirx register being set as the second pwm period begins. figure 23-19: example of steering even t at end of instruction (strxsync = 0) figure 23-20: example of steering event at beginning of instruction (strxsync = 1) note: when the microcontroller is released from reset, all of the i/o pins are in the high-impedance state. the external cir- cuits must keep the power switch devices in the off state until the microcontroller drives the i/o pins with the proper signal levels or activates the pwm output(s). pwm p1n = pwm strx p1 port data pwm period port data pwm port data p1n = pwm strx p1 port data
? 2010-2011 microchip technology inc. preliminary ds41414c-page 235 pic16(l)f1946/1947 23.4.8 alternate pin locations this module incorporates i/o pins that can be moved to other locations with the use of the alternate pin function register, apfcon. to determine which pins can be moved and what their default locations are upon a reset, see section 12.1 ?alternate pin function? for more information. table 23-10: summary of register s associated with enhanced pwm name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page ccpxcon pxm<1:0> (1) dcxb<1:0> ccpxm<3:0> 236 ccpxas ccpxase ccpxas<2:0> pssxac<1:0> pssxbd<1:0> 238 ccptmrs0 c4tsel<1:0> c3tsel<1:0> c2tsel<1:0> c1tsel<1:0> 237 ccptmrs1 ? ? ? ? ? ? c5tsel<1:0> 237 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie2 osfie c2ie c1ie eeie bclie lcdie c3ie ccp2ie 95 pie3 ? ccp5ie ccp4ie ccp3ie tmr6ie ? tmr4ie ? 96 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir2 osfif c2if c1if eeif bclif lcdif c3if ccp2if 99 pir3 ? ccp5if ccp4if ccp3if tmr6if ? tmr4if ? 100 prx timer2/4/6 period register 209* pstrxcon ? ? ? strxsync strxd strxc strxb strxa 240 pwmxcon pxrsen pxdc<6:0> 239 txcon ? txoutps<3:0> tmrxon txckps<:0>1 211 tmrx timer2/4/6 module register 209* trisa trisa7 trisa6 trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 216 trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 216 trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 216 trisd trisd7 trisd6 trisd5 trisd4 trisd3 trisd2 trisd1 trisd0 216 trise ? ? ? ? trise3 trise2 trise1 trise0 216 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by the pwm. note 1: applies to eccp modules only. * page provides register information.
pic16(l)f1946/1947 ds41414c-page 236 preliminary ? 2010-2011 microchip technology inc. 23.5 ccp control registers register 23-1: ccpxcon: ccpx control register r/w-00 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 pxm<1:0> (1) dcxb<1:0> ccpxm<3:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other reset ?1? = bit is set ?0? = bit is cleared bit 7-6 pxm<1:0>: enhanced pwm output configuration bits (1) capture mode: unused compare mode: unused i f ccpxm<3:2> = 00 , 01 , 10 : xx = pxa assigned as capture/compare input; pxb, pxc, pxd assigned as port pins if ccpxm<3:2> = 11 : 00 = single output; pxa modulated; pxb, pxc, pxd assigned as port pins 01 = full-bridge output forward; pxd modulated; pxa active; pxb, pxc inactive 10 = half-bridge output; pxa, pxb modulated with dead-band control; pxc, pxd assigned as port pins 11 = full-bridge output reverse; pxb modulated; pxc active; pxa, pxd inactive bit 5-4 dcxb<1:0>: pwm duty cycle least significant bits capture mode: unused compare mode: unused pwm mode: these bits are the two lsbs of the pwm duty cycle. the eight msbs 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 = 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 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: special event trigger (eccpx resets tmr1 or tmr3, sets ccpxif bit, eccp2 trigger also starts a/d conversion if a/d module is enabled) (1) ccp4/ccp5 only: 11xx =pwm mode eccp1/eccp2/eccp3 only: 1100 = pwm mode: pxa, pxc active-high; pxb, pxd active-high 1101 = pwm mode: pxa, pxc active-high; pxb, pxd active-low 1110 = pwm mode: pxa, pxc active-low; pxb, pxd active-high 1111 = pwm mode: pxa, pxc active-low; pxb, pxd active-low note 1: these bits are not implemented on ccp<5:4>.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 237 pic16(l)f1946/1947 register 23-2: ccptmrs0: pwm time r selection control register 0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 c4tsel<1:0> c3tsel<1:0> c2tsel<1:0> c1tsel<1:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-6 c4tsel<1:0>: ccp4 timer selection 00 = ccp4 is based off timer 2 in pwm mode 01 = ccp4 is based off timer 4 in pwm mode 10 = ccp4 is based off timer 6 in pwm mode 11 =reserved bit 5-4 c3tsel<1:0>: ccp3 timer selection 00 = ccp3 is based off timer 2 in pwm mode 01 = ccp3 is based off timer 4 in pwm mode 10 = ccp3 is based off timer 6 in pwm mode 11 =reserved bit 3-2 c2tsel<1:0>: ccp2 timer selection 00 = ccp2 is based off timer 2 in pwm mode 01 = ccp2 is based off timer 4 in pwm mode 10 = ccp2 is based off timer 6 in pwm mode 11 =reserved bit 1-0 c1tsel<1:0>: ccp1 timer selection 00 = ccp1 is based off timer 2 in pwm mode 01 = ccp1 is based off timer 4 in pwm mode 10 = ccp1 is based off timer 6 in pwm mode 11 =reserved register 23-3: ccptmrs1: pwm time r selection control register 1 u-0 u-0 u-0 u-0 u-0 u-0 r/w-0/0 r/w-0/0 ? ? ? ? ? ? c5tsel<1:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-2 unimplemented: read as ? 0 ? bit 1-0 c5tsel<1:0>: ccp5 timer selection 00 = ccp5 is based off timer 2 in pwm mode 01 = ccp5 is based off timer 4 in pwm mode 10 = ccp5 is based off timer 6 in pwm mode 11 =reserved
pic16(l)f1946/1947 ds41414c-page 238 preliminary ? 2010-2011 microchip technology inc. register 23-4: ccpxas: ccpx aut o-shutdown control register r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 ccpxase ccpxas<2:0> pssxac<1:0> pssxbd<1:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 ccpxase: ccpx auto-shutdown event status bit 1 = a shutdown event has occurred; ccpx outputs are in shutdown state 0 = ccpx outputs are operating bit 6-4 ccpxas<2:0>: ccpx auto-shutdown source select bits 000 = auto-shutdown is disabled 001 = comparator c1 output high (1) 010 = comparator c2 output high (1, 2) 011 = either comparator c1 or c2 high (1, 2) 100 =v il on int pin 101 =v il on int pin or comparator c1 high (1) 110 =v il on int pin or comparator c2 high (1, 2) 111 =v il on int pin or comparator c1 or comparator c2 high (1, 2) bit 3-2 pssxac<1:0>: pins pxa and pxc shutdown state control bits 00 = drive pins pxa and pxc to ? 0 ? 01 = drive pins pxa and pxc to ? 1 ? 1x = pins pxa and pxc 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 = pins pxb and pxd tri-state note 1: if cxsync is enabled, the shutdown will be delayed by timer1. 2: for pic16f1946/47 devices in eccp3 mode, ccpxas uses c3 instead of c2.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 239 pic16(l)f1946/1947 register 23-5: pwmxcon: enhanced pwm control register r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 pxrsen pxdc<6:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 pxrsen: pwm restart enable bit 1 = upon auto-shutdown, the ccpxase bit clears automatically once the shutdown event goes away; the pwm restarts automatically 0 = upon auto-shutdown, ccpxase must be cleared in software to restart the pwm bit 6-0 pxdc<6:0>: pwm delay count bits pxdcx = 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 transitions active note 1: bit resets to ? 0 ? with two-speed start-up and lp, xt or hs selected as the oscillator mode or fail-safe mode is enabled.
pic16(l)f1946/1947 ds41414c-page 240 preliminary ? 2010-2011 microchip technology inc. register 23-6: pstrxcon: pwm steering control register (1) u-0 u-0 u-0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-1/1 ? ? ? strxsync strxd strxc strxb strxa bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-5 unimplemented: read as ? 0 ? bit 4 strxsync: steering sync bit 1 = output steering update occurs on next pwm period 0 = output steering update occurs at the beginning of the instruction cycle boundary bit 3 strxd: steering enable bit d 1 = pxd pin has the pwm waveform with polarity control from ccpxm<1:0> 0 = pxd pin is assigned to port pin bit 2 strxc: steering enable bit c 1 = pxc pin has the pwm waveform with polarity control from ccpxm<1:0> 0 = pxc pin is assigned to port pin bit 1 strxb: steering enable bit b 1 = pxb pin has the pwm waveform with polarity control from ccpxm<1:0> 0 = pxb pin is assigned to port pin bit 0 strxa: steering enable bit a 1 = pxa pin has the pwm waveform with polarity control from ccpxm<1:0> 0 = pxa pin is assigned to 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 .
? 2010-2011 microchip technology inc. preliminary ds41414c-page 241 pic16(l)f1946/1947 24.0 master synchronous serial port (mssp1 and mssp2) module 24.1 master sspx (msspx) module overview the master synchronous serial port (msspx) module is a serial interface useful for communicating with other peripheral or microcontroller devices. these peripheral devices may be serial eeproms, shift registers, dis- play drivers, a/d converters, etc. the msspx module can operate in one of two modes: ? serial peripheral interface (spi) ? inter-integrated circuit (i 2 c?) the spi interface supports the following modes and features: ?master mode ? slave mode ? clock parity ? slave select synchronization (slave mode only) ? daisy-chain connection of slave devices figure 24-1 is a block diagram of the spi interface module. figure 24-1: msspx bloc k diagram (spi mode) ( ) read write data bus sspxsr reg sspxm<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 (ckp, cke) 4 tris bit sdox sspxbuf reg sdix ssx sckx baud rate generator (sspxadd)
pic16(l)f1946/1947 ds41414c-page 242 preliminary ? 2010-2011 microchip technology inc. the i 2 c interface supports the following modes and features: ?master mode ? slave mode ? byte nacking (slave mode) ? limited multi-master support ? 7-bit and 10-bit addressing ? start and stop interrupts ? interrupt masking ? clock stretching ? bus collision detection ? general call address matching ?address masking ? address hold and data hold modes ? selectable sdax hold times figure 24-2 is a block diagram of the i 2 c interface mod- ule in master mode. figure 24-3 is a diagram of the i 2 c interface module in slave mode. the pic16f1947 has two mssp modules, mssp1 and mssp2, each module operating independently from the other. figure 24-2: msspx block diagram (i 2 c? master mode) note 1: in devices with more than one mssp module, it is very important to pay close attention to sspxconx register names. ssp1con1 and ssp1con2 registers control different operational aspects of the same module, while ssp1con1 and ssp2con1 control the same features for two different modules. 2: 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, module i/o sig- nals, and bit names may use the generic designator ?x? to indicate the use of a numeral to distinguish a particular module when required. read write sspxsr start bit, stop bit, start bit detect, sspxbuf internal data bus set/reset: s, p, sspxstat, wcol, sspxov shift clock msb lsb sdax acknowledge generate (sspxcon2) stop bit detect write collision detect clock arbitration state counter for end of xmit/rcv sclx sclx in bus collision sdax in receive enable (rcen) clock cntl clock arbitrate/bcol detect (hold off clock source) [sspxm 3:0] baud rate reset sen, pen (sspxcon2) generator (sspxadd) address match detect set sspxif, bclxif
? 2010-2011 microchip technology inc. preliminary ds41414c-page 243 pic16(l)f1946/1947 figure 24-3: msspx block diagram (i 2 c? slave mode) read write sspxsr reg match detect sspxadd reg start and stop bit detect sspxbuf reg internal data bus addr match set, reset s, p bits (sspxstat reg) sclx sdax shift clock msb lsb sspxmsk reg
pic16(l)f1946/1947 ds41414c-page 244 preliminary ? 2010-2011 microchip technology inc. 24.2 spi mode overview the serial peripheral interface (spi) bus is a synchronous serial data communication bus that operates in full duplex mode. devices communicate in a master/slave environment where the master device initiates the communication. a slave device is controlled through a chip select known as slave select. the spi bus specifies four signal connections: ? serial clock (sckx) ? serial data out (sdox) ? serial data in (sdix) ? slave select (ssx ) figure 24-1 shows the block diagram of the msspx module when operating in spi mode. the spi bus operates with a single master device and one or more slave devices. when multiple slave devices are used, an independent slave select con- nection is required from the master device to each slave device. figure 24-4 shows a typical connection between a master device and multiple slave devices. the master selects only one slave at a time. most slave devices have tri-state outputs so their output signal appears disconnected from the bus when they are not selected. transmissions involve two shift registers, eight bits in size, one in the master and one in the slave. with either the master or the slave device, data is always shifted out one bit at a time, with the most significant bit (msb) shifted out first. at the same time, a new least significant bit (lsb) is shifted into the same register. figure 24-5 shows a typical connection between two processors configured as master and slave devices. data is shifted out of both shift registers on the pro- grammed clock edge and latched on the opposite edge of the clock. the master device transmits information out on its sdox output pin which is connected to, and received by, the slave?s sdix input pin. the slave device trans- mits information out on its sdox output pin, which is connected to, and received by, the master?s sdix input pin. to begin communication, the master device first sends out the clock signal. both the master and the slave devices should be configured for the same clock polar- ity. the master device starts a transmission by sending out the msb from its shift register. the slave device reads this bit from that same line and saves it into the lsb position of its shift register. during each spi clock cycle, a full duplex data transmission occurs. this means that while the master device is sending out the msb from its shift register (on its sdox pin) and the slave device is reading this bit and saving it as the lsb of its shift register, that the slave device is also sending out the msb from its shift register (on its sdox pin) and the master device is reading this bit and saving it as the lsb of its shift register. after 8 bits have been shifted out, the master and slave have exchanged register values. if there is more data to exchange, the shift registers are loaded with new data and the process repeats itself. whether the data is meaningful or not (dummy data), depends on the application software. this leads to three scenarios for data transmission: ? master sends useful data and slave sends dummy data. ? master sends useful data and slave sends useful data. ? master sends dummy data and slave sends useful data. transmissions may involve any number of clock cycles. when there is no more data to be transmitted, the master stops sending the clock signal and it deselects the slave. every slave device connected to the bus that has not been selected through its slave select line must disre- gard the clock and transmission signals and must not transmit out any data of its own.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 245 pic16(l)f1946/1947 figure 24-4: spi master and multiple slave connection 24.2.1 spi mode registers the msspx module has five registers for spi mode operation. these are: ? msspx status register (sspxstat) ? msspx control register 1 (sspxcon1) ? msspx control register 3 (sspxcon3) ? msspx data buffer register (sspxbuf) ? msspx address register (sspxadd) ? msspx shift register (sspxsr) (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. in one spi master mode, sspxadd can be loaded with a value used in the baud rate generator. more information on the baud rate generator is available in section 24.7 ?baud rate generator? . sspxsr is the shift register used for shifting data in and out. sspxbuf provides indirect access to the sspxsr register. sspxbuf is the buffer register to which data bytes are written, and from which data bytes are read. in receive operations, sspxsr and sspxbuf together create a 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 buffered. a write to sspxbuf will write to both sspxbuf and sspxsr. spi master sckx sdox sdix general i/o general i/o general i/o sckx sdix sdox ssx spi slave #1 sckx sdix sdox ssx spi slave #2 sckx sdix sdox ssx spi slave #3
pic16(l)f1946/1947 ds41414c-page 246 preliminary ? 2010-2011 microchip technology inc. 24.2.2 spi mode 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) to enable the serial port, sspx enable bit, sspxen of the sspxcon1 register, must be set. to reset or recon- figure spi mode, clear the sspxen bit, re-initialize the sspxconx registers and then set the sspxen 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 corresponding tris bit set ? sdox must have corresponding tris bit cleared ? sckx (master mode) must have corresponding tris bit cleared ? sckx (slave mode) must have corresponding tris bit set ? ssx must have corresponding tris 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. the msspx consists of a transmit/receive shift register (sspxsr) and a buffer register (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 of the sspxstat register, 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 of the sspxcon1 register, will be set. user software must clear the wcol bit to allow the following write(s) to the sspxbuf register to complete 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 of the sspxstat register, 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 msspx 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. figure 24-5: spi mast er/slave connection serial input buffer (buf) shift register (sspxsr) msb lsb sdox sdix processor 1 sckx spi master sspxm<3:0> = 00xx serial input buffer (sspxbuf) shift register (sspxsr) lsb msb sdix sdox processor 2 sckx spi slave sspxm<3:0> = 010x serial clock ssx slave select general i/o (optional) = 1010
? 2010-2011 microchip technology inc. preliminary ds41414c-page 247 pic16(l)f1946/1947 24.2.3 spi master mode the master can initiate the data transfer at any time because it controls the sckx line. the master determines when the slave (processor 2, figure 24-5 ) 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). the clock polarity is selected by appropriately programming the ckp bit of the sspxcon1 register and the cke bit of the sspxstat register. this then, would give waveforms for spi communication as shown in figure 24-6 , figure 24-8 and figure 24-9 , 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 ? fosc/(4 * (sspxadd + 1)) figure 24-6 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 24-6: 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 ) bit 0
pic16(l)f1946/1947 ds41414c-page 248 preliminary ? 2010-2011 microchip technology inc. 24.2.4 spi slave mode in slave mode, the data is transmitted and received as external clock pulses appear on sckx. when the last bit is latched, the sspxif interrupt flag bit is set. before enabling the module in spi slave mode, the clock line must match the proper idle state. the clock line can be observed by reading the sckx pin. the idle state is determined by the ckp bit of the sspxcon1 register. while in slave mode, the external clock is supplied by the external clock source on the sckx pin. this exter- nal 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. the shift register is clocked from the sckx pin input and when a byte is received, the device will gen- erate an interrupt. if enabled, the device will wake-up from sleep. 24.2.4.1 daisy-chain configuration the spi bus can sometimes be connected in a daisy-chain configuration. the first slave output is con- nected to the second slave input, the second slave output is connected to the third slave input, and so on. the final slave output is connected to the master input. each slave sends out, during a second group of clock pulses, an exact copy of what was received during the first group of clock pulses. the whole chain acts as one large communication shift register. the daisy-chain feature only requires a single slave select line from the master device. figure 24-7 shows the block diagram of a typical daisy-chain connection when operating in spi mode. in a daisy-chain configuration, only the most recent byte on the bus is required by the slave. setting the boen bit of the sspxcon3 register will enable writes to the sspxbuf register, even if the previous byte has not been read. this allows the software to ignore data that may not apply to it. 24.2.5 slave select synchronization the slave select can also be used to synchronize com- munication. the slave select line is held high until the master device is ready to communicate. when the slave select line is pulled low, the slave knows that a new transmission is starting. if the slave fails to receive the communication properly, it will be reset at the end of the transmission, when the slave select line returns to a high state. the slave is then ready to receive a new transmission when the slave select line is pulled low again. if the slave select line is not used, there is a risk that the slave will even- tually become out of sync with the master. if the slave misses a bit, it will always be one bit off in future trans- missions. use of the slave select line allows the slave and master to align themselves at the beginning of each transmission. the ssx pin allows a synchronous slave mode. the spi must be in slave mode with ssx pin control enabled (sspxcon1<3:0> = 0100 ). 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 applica- tion. 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 sspxen bit. note 1: when the spi is in slave mode with ssx pin control enabled (sspxcon1<3:0> = 0100 ), the spi module will reset if the ssx pin is set to v dd . 2: when the spi is used in slave mode with cke set; the user must enable ssx pin control. 3: while operated in spi slave mode the smp bit of the sspxstat register must remain clear.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 249 pic16(l)f1946/1947 figure 24-7: spi daisy-chain connection figure 24-8: slave sele ct synchronous waveform spi master sck sdox sdix general i/o sck sdix sdox ssx spi slave #1 sck sdix sdox ssx spi slave #2 sck sdix sdox ssx spi slave #3 sckx (ckp = 1 sckx (ckp = 0 input sample sdix bit 7 sdox bit 7 bit 6 bit 7 sspxif interrupt cke = 0 ) cke = 0 ) write to sspxbuf sspxsr to sspxbuf ssx flag bit 0 bit 7 bit 0 bit 6 sspxbuf to sspxsr shift register sspxsr and bit count are reset
pic16(l)f1946/1947 ds41414c-page 250 preliminary ? 2010-2011 microchip technology inc. figure 24-9: spi mode wavefo rm (slave mode with cke = 0 ) figure 24-10: 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 cke = 0 ) cke = 0 ) write to sspxbuf sspxsr to sspxbuf ssx flag optional bit 0 detection active write collision valid 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 cke = 1 ) cke = 1 ) write to sspxbuf sspxsr to sspxbuf ssx flag not optional write collision detection active valid
? 2010-2011 microchip technology inc. preliminary ds41414c-page 251 pic16(l)f1946/1947 24.2.6 spi operation in sleep mode in spi master mode, module clocks may be operating at a different speed than when in full power mode; in the case of the sleep mode, all clocks are halted. special care must be taken by the user when the msspx clock is much faster than the system clock. in slave mode, when msspx interrupts are enabled, after the master completes sending data, an msspx interrupt will wake the controller from sleep. if an exit from sleep mode is not desired, msspx inter- rupts should be disabled. in spi master mode, when the sleep mode is selected, all module clocks are halted and the transmis- sion/reception will remain in that state until the device wakes. after the device returns to run mode, the mod- ule 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 sleep mode and data to be shifted into the spi transmit/receive shift register. when all 8 bits have been received, the msspx interrupt flag bit will be set and if enabled, will wake the device. table 24-1: summary of registers as sociated with spi operation name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page ansela ansa7 ansa6 ansa5 ansa4 ansa3 ansa2 ansa1 ansa0 129 apfcon p3csel p3bsel p2dsel p2csel p2bsel ccp2sel p1csel p1bsel 126 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie4 ? ? rc2ie tx2ie ? ? bcl2ie ssp2ie 97 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir4 ? ? rc2if tx2if ? ? bcl2if ssp2if 101 sspxbuf synchronous serial port receive buffer/transmit register 245* sspxcon1 wcol sspxov sspxen ckp sspxm<3:0> 291 sspxcon3 acktim pcie scie boen sdaht sbcde ahen dhen 294 sspxstat smp cke d/a p s r/w ua bf 289 trisa trisa7 trisa6 trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 128 trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 131 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by the msspx in spi mode. * page provides register information.
pic16(l)f1946/1947 ds41414c-page 252 preliminary ? 2010-2011 microchip technology inc. 24.3 i 2 c mode overview the inter-integrated circuit bus (i2c?) is a multi-master serial data communication bus. devices communicate in a master/slave environment where the master devices initiate the communication. a slave device is controlled through addressing. the i 2 c bus specifies two signal connections: ? serial clock (sclx) ? serial data (sdax) figure 24-11 shows the block diagram of the msspx module when operating in i 2 c mode. both the sclx and sdax connections are bidirectional open-drain lines, each requiring pull-up resistors for the supply voltage. pulling the line to ground is considered a logical zero and letting the line float is considered a logical one. figure 24-11 shows a typical connection between two processors configured as master and slave devices. the i 2 c bus can operate with one or more master devices and one or more slave devices. there are four potential modes of operation for a given device: ? master transmit mode (master is transmitting data to a slave) ? master receive mode (master is receiving data from a slave) ?slave transmit mode (slave is transmitting data to a master) ? slave receive mode (slave is receiving data from the master) to begin communication, a master device starts out in master transmit mode. the master device sends out a start bit followed by the address byte of the slave it intends to communicate with. this is followed by a sin- gle read/write bit, which determines whether the mas- ter intends to transmit to or receive data from the slave device. if the requested slave exists on the bus, it will respond with an acknowledge bit, otherwise known as an ack . the master then continues in either transmit mode or receive mode and the slave continues in the comple- ment, either in receive mode or transmit mode, respectively. a start bit is indicated by a high-to-low transition of the sdax line while the sclx line is held high. address and data bytes are sent out, most significant bit (msb) first. the read/write bit is sent out as a logical one when the master intends to read data from the slave, and is sent out as a logical zero when it intends to write data to the slave. figure 24-11: i 2 c master/ slave connection the acknowledge bit (ack ) is an active-low signal, which holds the sdax line low to indicate to the trans- mitter that the slave device has received the transmit- ted data and is ready to receive more. the transition of a data bit is always performed while the sclx line is held low. transitions that occur while the sclx line is held high are used to indicate start and stop bits. if the master intends to write to the slave, then it repeat- edly sends out a byte of data, with the slave responding after each byte with an ack bit. in this example, the master device is in master transmit mode and the slave is in slave receive mode. if the master intends to read from the slave, then it repeatedly receives a byte of data from the slave, and responds after each byte with an ack bit. in this exam- ple, the master device is in master receive mode and the slave is slave transmit mode. on the last byte of data communicated, the master device may end the transmission by sending a stop bit. if the master device is in receive mode, it sends the stop bit in place of the last ack bit. a stop bit is indi- cated by a low-to-high transition of the sdax line while the sclx line is held high. in some cases, the master may want to maintain con- trol of the bus and re-initiate another transmission. if so, the master device may send another start bit in place of the stop bit or last ack bit when it is in receive mode. the i 2 c bus specifies three message protocols; ? single message where a master writes data to a slave. ? single message where a master reads data from a slave. ? combined message where a master initiates a minimum of two writes, or two reads, or a combination of writes and reads, to one or more slaves. master sclx sdax sclx sdax slave v dd v dd
? 2010-2011 microchip technology inc. preliminary ds41414c-page 253 pic16(l)f1946/1947 when one device is transmitting a logical one, or letting the line float, and a second device is transmitting a log- ical zero, or holding the line low, the first device can detect that the line is not a logical one. this detection, when used on the sclx line, is called clock stretching. clock stretching gives slave devices a mechanism to control the flow of data. when this detection is used on the sdax line, it is called arbitration. arbitration ensures that there is only one master device communi- cating at any single time. 24.3.1 clock stretching when a slave device has not completed processing data, it can delay the transfer of more data through the process of clock stretching. an addressed slave device may hold the sclx clock line low after receiving or sending a bit, indicating that it is not yet ready to con- tinue. the master that is communicating with the slave will attempt to raise the sclx line in order to transfer the next bit, but will detect that the clock line has not yet been released. because the sclx connection is open-drain, the slave has the ability to hold that line low until it is ready to continue communicating. clock stretching allows receivers that cannot keep up with a transmitter to control the flow of incoming data. 24.3.2 arbitration each master device must monitor the bus for start and stop bits. if the device detects that the bus is busy, it cannot begin a new message until the bus returns to an idle state. however, two master devices may try to initiate a trans- mission on or about the same time. when this occurs, the process of arbitration begins. each transmitter checks the level of the sdax data line and compares it to the level that it expects to find. the first transmitter to observe that the two levels don?t match, loses arbitra- tion, and must stop transmitting on the sdax line. for example, if one transmitter holds the sdax line to a logical one (lets it float) and a second transmitter holds it to a logical zero (pulls it low), the result is that the sdax line will be low. the first transmitter then observes that the level of the line is different than expected and concludes that another transmitter is communicating. the first transmitter to notice this difference is the one that loses arbitration and must stop driving the sdax line. if this transmitter is also a master device, it also must stop driving the sclx line. it then can monitor the lines for a stop condition before trying to reissue its transmission. in the meantime, the other device that has not noticed any difference between the expected and actual levels on the sdax line continues with its original transmission. it can do so without any compli- cations, because so far, the transmission appears exactly as expected with no other transmitter disturbing the message. slave transmit mode can also be arbitrated, when a master addresses multiple slaves, but this is less com- mon. if two master devices are sending a message to two dif- ferent slave devices at the address stage, the master sending the lower slave address always wins arbitra- tion. when two master devices send messages to the same slave address, and addresses can sometimes refer to multiple slaves, the arbitration process must continue into the data stage. arbitration usually occurs very rarely, but it is a neces- sary process for proper multi-master support. 24.4 i 2 c mode operation all msspx i 2 c communication is byte oriented and shifted out msb first. six sfr registers and 2 interrupt flags interface the module with the pic ? microcon- troller and user software. two pins, sdax and sclx, are exercised by the module to communicate with other external i 2 c devices. 24.4.1 byte format all communication in i 2 c is done in 9-bit segments. a byte is sent from a master to a slave or vice-versa, fol- lowed by an acknowledge bit sent back. after the 8th falling edge of the sclx line, the device outputting data on the sdax changes that pin to an input and reads in an acknowledge value on the next clock pulse. the clock signal, sclx, is provided by the master. data is valid to change while the sclx signal is low, and sampled on the rising edge of the clock. changes on the sdax line while the sclx line is high define special conditions on the bus, explained below. 24.4.2 definition of i 2 c terminology there is language and terminology in the description of i 2 c communication that have definitions specific to i 2 c. that word usage is defined below and may be used in the rest of this document without explanation. this table was adapted from the philips i 2 c specification. 24.4.3 sdax and sclx pins selection of any i 2 c mode with the sspxen bit set, forces the sclx and sdax pins to be open-drain. these pins should be set by the user to inputs by set- ting the appropriate tris bits. note: data is tied to output zero when an i 2 c mode is enabled.
pic16(l)f1946/1947 ds41414c-page 254 preliminary ? 2010-2011 microchip technology inc. 24.4.4 sdax hold time the hold time of the sdax pin is selected by the sdaht bit of the sspxcon3 register. hold time is the time sdax is held valid after the falling edge of sclx. setting the sdaht bit selects a longer 300 ns mini- mum hold time and may help on buses with large capacitance. table 24-2: i 2 c bus terms term description transmitter the device which shifts data out onto the bus. receiver the device which shifts data in from the bus. master the device that initiates a transfer, generates clock signals and termi- nates a transfer. slave the device addressed by the mas- ter. multi-master a bus with more than one device that can initiate data transfers. arbitration procedure to ensure that only one master at a time controls the bus. winning arbitration ensures that the message is not corrupted. synchronization procedure to synchronize the clocks of two or more devices on the bus. idle no master is controlling the bus, and both sdax and sclx lines are high. active any time one or more master devices are controlling the bus. addressed slave slave device that has received a matching address and is actively being clocked by a master. matching address address byte that is clocked into a slave that matches the value stored in sspxadd. write request slave receives a matching address with r/w bit clear, and is ready to clock in data. read request master sends an address byte with the r/w bit set, indicating that it wishes to clock data out of the slave. this data is the next and all following bytes until a restart or stop. clock stretching when a device on the bus holds sclx low to stall communication. bus collision any time the sdax line is sampled low by the module while it is out- putting and expected high state.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 255 pic16(l)f1946/1947 24.4.5 start condition the i 2 c specification defines a start condition as a transition of sdax from a high to a low state while sclx line is high. a start condition is always gener- ated by the master and signifies the transition of the bus from an idle to an active state. figure 24-10 shows wave forms for start and stop conditions. a bus collision can occur on a start condition if the module samples the sdax line low before asserting it low. this does not conform to the i 2 c specification that states no bus collision can occur on a start. 24.4.6 stop condition a stop condition is a transition of the sdax line from low-to-high state while the sclx line is high. 24.4.7 restart condition a restart is valid any time that a stop would be valid. a master can issue a restart if it wishes to hold the bus after terminating the current transfer. a restart has the same effect on the slave that a start would, resetting all slave logic and preparing it to clock in an address. the master may want to address the same or another slave. in 10-bit addressing slave mode a restart is required for the master to clock data out of the addressed slave. once a slave has been fully addressed, match- ing both high and low address bytes, the master can issue a restart and the high address byte with the r/w bit set. the slave logic will then hold the clock and prepare to clock out data. after a full match with r/w clear in 10-bit mode, a prior match flag is set and maintained. until a stop condi- tion, a high address with r/w clear, or high address match fails. 24.4.8 start/stop condition interrupt masking the scie and pcie bits of the sspxcon3 register can enable the generation of an interrupt in slave modes that do not typically support this function. slave modes where interrupt on start and stop detect are already enabled, these bits will have no effect. figure 24-12: i 2 c start and stop conditions figure 24-13: i 2 c restart condition note: at least one sclx low time must appear before a stop is valid, therefore, if the sdax line goes low then high again while the sclx line stays high, only the start condition is detected. sdax sclx p stop condition s start condition change of data allowed change of data allowed restart condition sr change of data allowed change of data allowed
pic16(l)f1946/1947 ds41414c-page 256 preliminary ? 2010-2011 microchip technology inc. 24.4.9 acknowledge sequence the 9th sclx pulse for any transferred byte in i 2 c is dedicated as an acknowledge. it allows receiving devices to respond back to the transmitter by pulling the sdax line low. the transmitter must release con- trol of the line during this time to shift in the response. the acknowledge (ack ) is an active-low signal, pull- ing the sdax line low indicated to the transmitter that the device has received the transmitted data and is ready to receive more. the result of an ack is placed in the ackstat bit of the sspxcon2 register. slave software, when the ahen and dhen bits are set, allow the user to set the ack value sent back to the transmitter. the ackdt bit of the sspxcon2 reg- ister is set/cleared to determine the response. slave hardware will generate an ack response if the ahen and dhen bits of the sspxcon3 register are clear. there are certain conditions where an ack will not be sent by the slave. if the bf bit of the sspxstat regis- ter or the sspxov bit of the sspxcon1 register are set when a byte is received. when the module is addressed, after the 8th falling edge of sclx on the bus, the acktim bit of the sspxcon3 register is set. the acktim bit indicates the acknowledge time of the active bus. the acktim status bit is only active when the ahen bit or dhen bit is enabled. 24.5 i 2 c slave mode operation the msspx slave mode operates in one of four modes selected in the sspxm bits of sspxcon1 reg- ister. the modes can be divided into 7-bit and 10-bit addressing mode. 10-bit addressing modes operate the same as 7-bit with some additional overhead for handling the larger addresses. modes with start and stop bit interrupts operated the same as the other modes with sspxif additionally getting set upon detection of a start, restart, or stop condition. 24.5.1 slave mode addresses the sspxadd register ( register 24-6 ) contains the slave mode address. the first byte received after a start or restart condition is compared against the value stored in this register. if the byte matches, the value is loaded into the sspxbuf register and an interrupt is generated. if the value does not match, the module goes idle and no indication is given to the soft- ware that anything happened. the sspx mask register ( register 24-5 ) affects the address matching process. see section 24.5.9 ?sspx mask register? for more information. 24.5.1.1 i 2 c slave 7-bit addressing mode in 7-bit addressing mode, the lsb of the received data byte is ignored when determining if there is an address match. 24.5.1.2 i 2 c slave 10-bit addressing mode in 10-bit addressing mode, the first received byte is compared to the binary value of ?1 1 1 1 0 a9 a8 0?. a9 and a8 are the two msb of the 10-bit address and stored in bits 2 and 1 of the sspxadd register. after the acknowledge of the high byte, the ua bit is set and sclx is held low until the user updates sspxadd with the low address. the low address byte is clocked in and all 8 bits are compared to the low address value in sspxadd. even if there is not an address match; sspxif and ua are set, and sclx is held low until sspxadd is updated to receive a high byte again. when sspxadd is updated, the ua bit is cleared. this ensures the module is ready to receive the high address byte on the next communication. a high and low address match as a write request is required at the start of all 10-bit addressing communi- cation. a transmission can be initiated by issuing a restart once the slave is addressed, and clocking in the high address with the r/w bit set. the slave hard- ware will then acknowledge the read request and pre- pare to clock out data. this is only valid for a slave after it has received a complete high and low address byte match.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 257 pic16(l)f1946/1947 24.5.2 slave reception when the r/w bit of a matching received address byte is clear, the r/w bit of the sspxstat register is cleared. the received address is loaded into the sspxbuf register and acknowledged. when the overflow condition exists for a received address, then not acknowledge is given. an overflow condition is defined as either bit bf bit of the sspxstat register is set, or bit sspxov bit of the sspxcon1 register is set. the boen bit of the sspxcon3 register modifies this operation. for more information see register 24-4 . an msspx interrupt is generated for each transferred data byte. flag bit, sspxif, must be cleared by software. when the sen bit of the sspxcon2 register is set, sclx will be held low (clock stretch) following each received byte. the clock must be released by setting the ckp bit of the sspxcon1 register, except sometimes in 10-bit mode. see section 24.2.3 ?spi master mode? for more detail. 24.5.2.1 7-bit addressing reception this section describes a standard sequence of events for the msspx module configured as an i 2 c slave in 7-bit addressing mode. all decisions made by hard- ware or software and their effect on reception. figure 24-13 and figure 24-14 is used as a visual reference for this description. this is a step by step process of what typically must be done to accomplish i 2 c communication. 1. start bit detected. 2. s bit of sspxstat is set; sspxif is set if inter- rupt on start detect is enabled. 3. matching address with r/w bit clear is received. 4. the slave pulls sdax low sending an ack to the master, and sets sspxif bit. 5. software clears the sspxif bit. 6. software reads received address from sspxbuf clearing the bf flag. 7. if sen = 1 ; slave software sets ckp bit to release the sclx line. 8. the master clocks out a data byte. 9. slave drives sdax low sending an ack to the master, and sets sspxif bit. 10. software clears sspxif. 11. software reads the received byte from sspxbuf clearing bf. 12. steps 8-12 are repeated for all received bytes from the master. 13. master sends stop condition, setting p bit of sspxstat, and the bus goes idle. 24.5.2.2 7-bit reception with ahen and dhen slave device reception with ahen and dhen set operate the same as without these options with extra interrupts and clock stretching added after the 8th fall- ing edge of sclx. these additional interrupts allow the slave software to decide whether it wants to ack the receive address or data byte, rather than the hard- ware. this functionality adds support for pmbus? that was not present on previous versions of this module. this list describes the steps that need to be taken by slave software to use these options for i 2 c communi- cation. figure 24-15 displays a module using both address and data holding. figure 24-16 includes the operation with the sen bit of the sspxcon2 register set. 1. s bit of sspxstat is set; sspxif is set if inter- rupt on start detect is enabled. 2. matching address with r/w bit clear is clocked in. sspxif is set and ckp cleared after the 8th falling edge of sclx. 3. slave clears the sspxif. 4. slave can look at the acktim bit of the sspxcon3 register to determine if the sspxif was after or before the ack. 5. slave reads the address value from sspxbuf, clearing the bf flag. 6. slave sets ack value clocked out to the master by setting ackdt. 7. slave releases the clock by setting ckp. 8. sspxif is set after an ack , not after a nack. 9. if sen = 1 the slave hardware will stretch the clock after the ack. 10. slave clears sspxif. 11. sspxif set and ckp cleared after 8th falling edge of sclx for a received data byte. 12. slave looks at acktim bit of sspxcon3 to determine the source of the interrupt. 13. slave reads the received data from sspxbuf clearing bf. 14. steps 7-14 are the same for each received data byte. 15. communication is ended by either the slave sending an ack = 1 , or the master sending a stop condition. if a stop is sent and interrupt on stop detect is disabled, the slave will only know by polling the p bit of the sststat register. note: sspxif is still set after the 9th falling edge of sclx even if there is no clock stretching and bf has been cleared. only if nack is sent to master is sspxif not set
pic16(l)f1946/1947 ds41414c-page 258 preliminary ? 2010-2011 microchip technology inc. figure 24-14: i 2 c slave, 7-bit address, reception (sen = 0 , ahen = 0 , dhen = 0 ) receiving address ack receiving data ack receiving data ack = 1 a7 a6 a5 a4 a3 a2 a1 d7 d6 d5 d4 d3 d2 d1 d0 d7 d6 d5 d4 d3 d2 d1 d0 sdax sclx sspxif bf sspxov 12345678 12345678 12345678 9 9 9 ack is not sent. sspxov set because sspxbuf is still full. cleared by software first byte of data is available in sspxbuf sspxbuf is read sspxif set on 9th falling edge of sclx cleared by software p bus master sends stop condition s from slave to master
? 2010-2011 microchip technology inc. preliminary ds41414c-page 259 pic16(l)f1946/1947 figure 24-15: i 2 c slave, 7-bit address, reception (sen = 1 , ahen = 0 , dhen = 0 ) sen sen a7 a6 a5 a4 a3 a2 a1 d7 d6 d5 d4 d3 d2 d1 d0 d7 d6 d5 d4 d3 d2 d1 d0 sdax sclx 123456789 123456789 123456789 p sspxif set on 9th sclx is not held ckp is written to 1 in software, ckp is written to ? 1 ? in software, ack low because falling edge of sclx releasing sclx ack is not sent. bus master sends ckp sspxov bf sspxif sspxov set because sspxbuf is still full. cleared by software first byte of data is available in sspxbuf ack = 1 cleared by software sspxbuf is read clock is held low until ckp is set to ? 1 ? releasing sclx stop condition s ack ack receive address receive data receive data r/w= 0
pic16(l)f1946/1947 ds41414c-page 260 preliminary ? 2010-2011 microchip technology inc. figure 24-16: i 2 c slave, 7-bit address, reception (sen = 0 , ahen = 1 , dhen = 1 ) receiving address receiving data received data p a7 a6 a5 a4 a3 a2 a1 d7 d6 d5 d4 d3 d2 d1 d0 d7 d6 d5 d4 d3 d2 d1 d0 sdax sclx bf ckp s p 12 3 4 56 7 8 9 12345678 9 12345678 master sends stop condition s data is read from sspxbuf cleared by software sspxif is set on 9th falling edge of sclx, after ack ckp set by software, sclx is released slave software 9 acktim cleared by hardware in 9th rising edge of sclx sets ackdt to not ack when dhen= 1 : ckp is cleared by hardware on 8th falling edge of sclx slave software clears ackdt to ack the received byte acktim set by hardware on 8th falling edge of sclx when ahen= 1 : ckp is cleared by hardware and sclx is stretched address is read from ssbuf acktim set by hardware on 8th falling edge of sclx ack master releases sdax to slave for ack sequence no interrupt after not ack from slave ack = 1 ack ackdt acktim sspxif if ahen = 1 : sspxif is set
? 2010-2011 microchip technology inc. preliminary ds41414c-page 261 pic16(l)f1946/1947 figure 24-17: i 2 c slave, 7-bit address, reception (sen = 1 , ahen = 1 , dhen = 1 ) receiving address receive data receive data a7 a6 a5 a4 a3 a2 a1 d7 d6 d5 d4 d3 d2 d1 d0 d7 d6 d5 d4 d3 d2 d1 d0 sdax sclx sspxif bf ackdt ckp s p ack s 12 34 5678 9 12 3 4567 8 9 12 345 67 8 9 ack ack cleared by software acktim is cleared by hardware sspxbuf can be set by software, read any time before next byte is loaded release sclx on 9th rising edge of sclx received address is loaded into sspxbuf slave software clears ackdt to ack r/w = 0 master releases sdax to slave for ack sequence the received byte when ahen = 1 ; on the 8th falling edge of sclx of an address byte, ckp is cleared acktim is set by hardware on 8th falling edge of sclx when dhen = 1 ; on the 8th falling edge of sclx of a received data byte, ckp is cleared received data is available on sspxbuf slave sends not ack ckp is not cleared if not ack p master sends stop condition no interrupt after if not ack from slave acktim
pic16(l)f1946/1947 ds41414c-page 262 preliminary ? 2010-2011 microchip technology inc. 24.5.3 slave 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, and an ack pulse is sent by the slave on the ninth bit. following the ack , slave hardware clears the ckp bit and the sclx pin is held low (see section 24.5.6 ?clock stretching? for more detail). 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 the sclx pin should be released by setting the ckp bit of the sspxcon1 register. 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. the ack pulse from the master-receiver is latched on the rising edge of the ninth sclx input pulse. this ack value is copied to the ackstat bit of the sspxcon2 register. if ackstat is set (not ack ), then the data transfer is complete. in this case, when the not ack is latched by the slave, the slave goes idle and waits 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, the sclx pin must be released by setting bit ckp. an msspx interrupt is generated for each data transfer byte. the sspxif bit must be cleared by 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. 24.5.3.1 slave mode bus collision a slave receives a read request and begins shifting data out on the sdax line. if a bus collision is detected and the sbcde bit of the sspxcon3 register is set, the bclxif bit of the pirx register is set. once a bus collision is detected, the slave goes idle and waits to be addressed again. user software can use the bclxif bit to handle a slave bus collision. 24.5.3.2 7-bit transmission a master device can transmit a read request to a slave, and then clock data out of the slave. the list below outlines what software for a slave will need to do to accomplish a standard transmission. figure 24-17 can be used as a reference to this list. 1. master sends a start condition on sdax and sclx. 2. s bit of sspxstat is set; sspxif is set if inter- rupt on start detect is enabled. 3. matching address with r/w bit set is received by the slave setting sspxif bit. 4. slave hardware generates an ack and sets sspxif. 5. sspxif bit is cleared by user. 6. software reads the received address from sspxbuf, clearing bf. 7. r/w is set so ckp was automatically cleared after the ack. 8. the slave software loads the transmit data into sspxbuf. 9. ckp bit is set releasing sclx, allowing the master to clock the data out of the slave. 10. sspxif is set after the ack response from the master is loaded into the ackstat register. 11. sspxif bit is cleared. 12. the slave software checks the ackstat bit to see if the master wants to clock out more data. 13. steps 9-13 are repeated for each transmitted byte. 14. if the master sends a not ack ; the clock is not held, but sspxif is still set. 15. the master sends a restart condition or a stop. 16. the slave is no longer addressed. note 1: if the master ack s the clock will be stretched. 2: ackstat is the only bit updated on the rising edge of sclx (9th) rather than the falling.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 263 pic16(l)f1946/1947 figure 24-18: i 2 c slave, 7-bit address, transmission (ahen = 0 ) receiving address automatic transmitting data automatic transmitting data a7 a6 a5 a4 a3 a2 a1 d7 d6 d5 d4 d3 d2 d1 d0 d7 d6 d5 d4 d3 d2 d1 d0 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 sdax sclx sspxif bf ckp ackstat r/w d/a s p received address when r/w is set r/w is copied from the indicates an address is read from sspxbuf sclx is always held low after 9th sclx falling edge matching address byte has been received masters not ack is copied to ackstat ckp is not held for not ack bf is automatically cleared after 8th falling edge of sclx data to transmit is loaded into sspxbuf set by software cleared by software ack ack ack r/w = 1 s p master sends stop condition
pic16(l)f1946/1947 ds41414c-page 264 preliminary ? 2010-2011 microchip technology inc. 24.5.3.3 7-bit transmission with address hold enabled setting the ahen bit of the sspxcon3 register enables additional clock stretching and interrupt gen- eration after the 8th falling edge of a received match- ing address. once a matching address has been clocked in, ckp is cleared and the sspxif interrupt is set. figure 24-18 displays a standard waveform of a 7-bit address slave transmission with ahen enabled. 1. bus starts idle. 2. master sends start condition; the s bit of sspxstat is set; sspxif is set if interrupt on start detect is enabled. 3. master sends matching address with r/w bit set. after the 8th falling edge of the sclx line the ckp bit is cleared and sspxif interrupt is generated. 4. slave software clears sspxif. 5. slave software reads acktim bit of sspxcon3 register, and r/w and d/a of the sspxstat register to determine the source of the interrupt. 6. slave reads the address value from the sspxbuf register clearing the bf bit. 7. slave software decides from this information if it wishes to ack or not ack and sets ackdt bit of the sspxcon2 register accordingly. 8. slave sets the ckp bit releasing sclx. 9. master clocks in the ack value from the slave. 10. slave hardware automatically clears the ckp bit and sets sspxif after the ack if the r/w bit is set. 11. slave software clears sspxif. 12. slave loads value to transmit to the master into sspxbuf setting the bf bit. 13. slave sets ckp bit releasing the clock. 14. master clocks out the data from the slave and sends an ack value on the 9th sclx pulse. 15. slave hardware copies the ack value into the ackstat bit of the sspxcon2 register. 16. steps 10-15 are repeated for each byte transmit- ted to the master from the slave. 17. if the master sends a not ack the slave releases the bus allowing the master to send a stop and end the communication. note: sspxbuf cannot be loaded until after the ack. note: master must send a not ack on the last byte to ensure that the slave releases the sclx line to receive a stop.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 265 pic16(l)f1946/1947 figure 24-19: i 2 c slave, 7-bit address, transmission (ahen = 1 ) receiving address automatic transmitting data automatic transmitting data a7 a6 a5 a4 a3 a2 a1 d7 d6 d5 d4 d3 d2 d1 d0 d7 d6 d5 d4 d3 d2 d1 d0 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 sdax sclx sspxif bf ackdt ackstat ckp r/w d/a received address is read from sspxbuf bf is automatically cleared after 8th falling edge of sclx data to transmit is loaded into sspxbuf cleared by software slave clears ackdt to ack address master?s ack response is copied to sspxstat ckp not cleared after not ack set by software, releases sclx acktim is cleared on 9th rising edge of sclx acktim is set on 8th falling edge of sclx when ahen = 1 ; ckp is cleared by hardware after receiving matching address. when r/w = 1 ; ckp is always cleared after ack s p master sends stop condition ack r/w = 1 master releases sdax to slave for ack sequence ack ack acktim
pic16(l)f1946/1947 ds41414c-page 266 preliminary ? 2010-2011 microchip technology inc. 24.5.4 slave mode 10-bit address reception this section describes a standard sequence of events for the msspx module configured as an i 2 c slave in 10-bit addressing mode. figure 24-19 is used as a visual reference for this description. this is a step by step process of what must be done by slave software to accomplish i 2 c communication. 1. bus starts idle. 2. master sends start condition; s bit of sspxstat is set; sspxif is set if interrupt on start detect is enabled. 3. master sends matching high address with r/w bit clear; ua bit of the sspxstat register is set. 4. slave sends ack and sspxif is set. 5. software clears the sspxif bit. 6. software reads received address from sspxbuf clearing the bf flag. 7. slave loads low address into sspxadd, releasing sclx. 8. master sends matching low address byte to the slave; ua bit is set. 9. slave sends ack and sspxif is set. 10. slave clears sspxif. 11. slave reads the received matching address from sspxbuf clearing bf. 12. slave loads high address into sspxadd. 13. master clocks a data byte to the slave and clocks out the slaves ack on the 9th sclx pulse; sspxif is set. 14. if sen bit of sspxcon2 is set, ckp is cleared by hardware and the clock is stretched. 15. slave clears sspxif. 16. slave reads the received byte from sspxbuf clearing bf. 17. if sen is set the slave sets ckp to release the sclx. 18. steps 13-17 repeat for each received byte. 19. master sends stop to end the transmission. 24.5.5 10-bit addressing with address or data hold reception using 10-bit addressing with ahen or dhen set is the same as with 7-bit modes. the only difference is the need to update the sspxadd register using the ua bit. all functionality, specifically when the ckp bit is cleared and sclx line is held low are the same. figure 24-20 can be used as a reference of a slave in 10-bit addressing with ahen set. figure 24-21 shows a standard waveform for a slave transmitter in 10-bit addressing mode. note: updates to the sspxadd register are not allowed until after the ack sequence. note: if the low address does not match, sspxif and ua are still set so that the slave soft- ware can set sspxadd back to the high address. bf is not set because there is no match. ckp is unaffected.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 267 pic16(l)f1946/1947 figure 24-20: i 2 c slave, 10-bit address, reception (sen = 1 , ahen = 0 , dhen = 0 ) sspxif receive first address byte ack receive second address byte ack receive data ack receive data ack 1 1 1 1 0 a9 a8 a7 a6 a5 a4 a3 a2 a1 a0 d7 d6 d5 d4 d3 d2 d1 d0 d7 d6 d5 d4 d3 d2 d1 d0 sdax sclx ua ckp 1 2345678 912345678 912345678 9 12345678 9 p master sends stop condition cleared by software receive address is software updates sspxadd data is read sclx is held low set by software, while ckp = 0 from sspxbuf releasing sclx when sen = 1 ; ckp is cleared after 9th falling edge of received byte read from sspxbuf and releases sclx when ua = 1 ; if address matches set by hardware on 9th falling edge sspxadd it is loaded into sspxbuf sclx is held low s bf
pic16(l)f1946/1947 ds41414c-page 268 preliminary ? 2010-2011 microchip technology inc. figure 24-21: i 2 c slave, 10-bit address, reception (sen = 0 , ahen = 1 , dhen = 0 ) receive first address byte ua receive second address byte ua receive data ack receive data 1 1 1 1 0 a9 a8 a7 a6 a5 a4 a3 a2 a1 a0 d7 d6 d5 d4 d3 d2 d1 d0 d7 d6 d5 sdax sclx sspxif bf ackdt ua ckp acktim 12345678 9 s ack ack 12 345678 9 12345678 91 2 sspxbuf is read from received data sspxbuf can be read anytime before the next received byte cleared by software falling edge of sclx not allowed until 9th update to sspxadd is set ckp with software releases sclx sclx clears ua and releases update of sspxadd, set by hardware on 9th falling edge slave software clears ackdt to ack the received byte if when ahen = 1 ; on the 8th falling edge of sclx of an address byte, ckp is cleared acktim is set by hardware on 8th falling edge of sclx cleared by software r/w = 0
? 2010-2011 microchip technology inc. preliminary ds41414c-page 269 pic16(l)f1946/1947 figure 24-22: i 2 c slave, 10-bit address, transmission (sen = 0 , ahen = 0 , dhen = 0 ) receiving address ack receiving second address byte sr receive first address byte ack transmitting data byte 1 1 1 1 0 a9 a8 a7 a6 a5 a4 a3 a2 a1 a0 1 1 1 1 0 a9 a8 d7 d6 d5 d4 d3 d2 d1 d0 sdax sclx sspxif bf ua ckp r/w d/a 1 2345 6789 1 2345 6789 1 23 4 5 6789 1 23456 789 ack = 1 p master sends stop condition master sends not ack master sends restart event ack r/w = 0 s cleared by software after sspxadd is updated, ua is cleared and sclx is released high address is loaded received address is data to transmit is set by software indicates an address when r/w = 1 ; r/w is copied from the set by hardware ua indicates sspxadd sspxbuf loaded with received address must be updated has been received loaded into sspxbuf releases sclx masters not ack is copied matching address byte ckp is cleared on 9th falling edge of sclx read from sspxbuf back into sspxadd ackstat set by hardware
pic16(l)f1946/1947 ds41414c-page 270 preliminary ? 2010-2011 microchip technology inc. 24.5.6 clock stretching clock stretching occurs when a device on the bus holds the sclx line low effectively pausing communi- cation. the slave may stretch the clock to allow more time to handle data or prepare a response for the mas- ter device. a master device is not concerned with stretching as anytime it is active on the bus and not transferring data it is stretching. any stretching done by a slave is invisible to the master software and han- dled by the hardware that generates sclx. the ckp bit of the sspxcon1 register is used to con- trol stretching in software. any time the ckp bit is cleared, the module will wait for the sclx line to go low and then hold it. setting ckp will release sclx and allow more communication. 24.5.6.1 normal clock stretching following an ack if the r/w bit of sspxstat is set, a read request, the slave hardware will clear ckp. this allows the slave time to update sspxbuf with data to transfer to the master. if the sen bit of sspxcon2 is set, the slave hardware will always stretch the clock after the ack sequence. once the slave is ready; ckp is set by software and communication resumes. 24.5.6.2 10-bit addressing mode in 10-bit addressing mode, when the ua bit is set, the clock is always stretched. this is the only time the sclx is stretched without ckp being cleared. sclx is released immediately after a write to sspxadd. 24.5.6.3 byte nacking when ahen bit of sspxcon3 is set; ckp is cleared by hardware after the 8th falling edge of sclx for a received matching address byte. when dhen bit of sspxcon3 is set; ckp is cleared after the 8th falling edge of sclx for received data. stretching after the 8th falling edge of sclx allows the slave to look at the received address or data and decide if it wants to ack the received data. 24.5.7 clock synchronization and the ckp bit any time the ckp bit is cleared, the module will wait for the sclx line to go low and then hold it. 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 released sclx. this ensures that a write to the ckp bit will not violate the minimum high time requirement for sclx (see figure 24-22 ). figure 24-23: clock synchronization timing note 1: the bf bit has no effect on if the clock will be stretched or not. this is different than previous versions of the module that would not stretch the clock, clear ckp, if sspxbuf was read before the 9th falling edge of sclx. 2: previous versions of the module did not stretch the clock for a transmission if sspxbuf was loaded before the 9th fall- ing edge of sclx. it is now always cleared for read requests. note: previous versions of the module did not stretch the clock if the second address byte did not match. sdax sclx dx ? ? 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 releases clock master device asserts clock
? 2010-2011 microchip technology inc. preliminary ds41414c-page 271 pic16(l)f1946/1947 24.5.8 general call address support the addressing procedure for the i 2 c bus is such that the first byte after the start condition usually deter- mines which device will be the slave addressed by the master device. 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 a reserved address in the i 2 c protocol, defined as address 0x00. when the gcen bit of the sspxcon2 register is set, the slave module will automatically ack the reception of this address regardless of the value stored in sspxadd. after the slave clocks in an address of all zeros with the r/w bit clear, an interrupt is generated and slave software can read sspxbuf and respond. figure 24-23 shows a general call reception sequence. in 10-bit address mode, the ua bit will not be set on the reception of the general call address. the slave will prepare to receive the second byte as data, just as it would in 7-bit mode. if the ahen bit of the sspxcon3 register is set, just as with any other address reception, the slave hard- ware will stretch the clock after the 8th falling edge of sclx. the slave must then set its ackdt value and release the clock with communication progressing as it would normally. figure 24-24: slave mode general call address sequence 24.5.9 sspx mask register an sspx mask (sspxmsk) register ( register 24-5 ) is available in i 2 c slave mode as a mask for the value held in the sspxsr register during an address comparison operation. a zero (? 0 ?) bit in the sspxmsk register has the effect of making the corresponding bit of the received address a ?don?t care?. this register is reset to all ? 1 ?s upon any reset condition and, therefore, has no effect on standard sspx operation until written with a mask value. the sspx mask register is active during: ? 7-bit address mode: address compare of a<7:1>. ? 10-bit address mode: address compare of a<7:0> only. the sspx mask has no effect during the reception of the first (high) byte of the address. sdax sclx s sspxif bf (sspxstat<0>) cleared by software sspxbuf is read r/w = 0 ack general call address address is compared to general call address receiving data ack 123456789123456789 d7 d6 d5 d4 d3 d2 d1 d0 after ack , set interrupt gcen (sspxcon2<7>) ? 1 ?
pic16(l)f1946/1947 ds41414c-page 272 preliminary ? 2010-2011 microchip technology inc. 24.6 i 2 c master mode master mode is enabled by setting and clearing the appropriate sspxm bits in the sspxcon1 register and by setting the sspxen bit. the sda and sck pins must be configured as inputs. the mssp peripheral hardware will override the output driver tris controls when necessary to drive the pins low. master mode of operation is supported by interrupt generation on the detection of the start and stop con- ditions. the stop (p) and start (s) bits are cleared from a reset or when the msspx module is disabled. con- trol of the i 2 c bus may be taken when the p bit is set, or the bus is idle. in firmware controlled master mode, user code conducts all i 2 c bus operations based on start and stop bit condition detection. start and stop condition detection is the only active circuitry in this mode. all other communication is done by the user software directly manipulating the sdax and sclx lines. the following events will cause the sspx interrupt flag bit, sspxif, to be set (sspx interrupt, if enabled): ? start condition detected ? stop condition detected ? data transfer byte transmitted/received ? acknowledge transmitted/received ? repeated start generated 24.6.1 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 con- tains 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. a baud rate generator is used to set the clock frequency output on sclx. see section 24.7 ?baud rate generator? for more detail. note 1: the msspx module, when configured in i 2 c master mode, does not allow queue- ing 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 2: when in master mode, start/stop detec- tion is masked and an interrupt is gener- ated when the sen/pen bit is cleared and the generation is complete.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 273 pic16(l)f1946/1947 24.6.2 clock arbitration clock arbitration occurs when the master, during any receive, transmit or repeated start/stop condition, releases 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<7:0> 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 24-25 ). figure 24-25: baud rate generator timing with clock arbitration 24.6.3 wcol status flag if the user writes the sspxbuf when a start, restart, stop, receive or transmit sequence is in progress, the wcol is set and the contents of the buffer are unchanged (the write does not occur). any time the wcol bit is set it indicates that an action on sspxbuf was attempted while the module was not idle. sdax sclx sclx deasserted but slave holds dx ? ? 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 note: because queueing of events is not allowed, writing to the lower 5 bits of sspxcon2 is disabled until the start condition is complete.
pic16(l)f1946/1947 ds41414c-page 274 preliminary ? 2010-2011 microchip technology inc. 24.6.4 i 2 c master mode start condition timing to initiate a start condition, the user sets the start enable bit, sen bit of the sspxcon2 register. if the sdax and sclx pins are sampled high, the baud rate generator is reloaded with the contents of sspxadd<7:0> 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 condition and causes the s bit of the sspxstat1 register to be set. following this, the baud rate generator is reloaded with the contents of sspxadd<7:0> and resumes its count. when the baud rate generator times out (t brg ), the sen bit of the sspxcon2 register will be automatically cleared by hardware; the baud rate generator is suspended, leaving the sdax line held low and the start condition is complete. figure 24-26: first start bit timing note 1: if at the beginning of the start condition, the sdax and sclx pins are already sam- pled low, or if during the start condition, 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. 2: the philips i 2 c specification states that a bus collision cannot occur on a start. 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
? 2010-2011 microchip technology inc. preliminary ds41414c-page 275 pic16(l)f1946/1947 24.6.5 i 2 c master mode repeated start condition timing a repeated start condition occurs when the rsen bit of the sspxcon2 register is programmed high and the master state machine is no longer active. 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 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, if sdax is sampled high, the sclx pin will be deasserted (brought high). when sclx is sampled high, the baud rate generator is reloaded 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. sclx is asserted low. following this, the rsen bit of the sspxcon2 register 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 of the sspxstat register will be set. the sspxif bit will not be set until the baud rate generator has timed out. figure 24-27: repeat start condition 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 ?. sdax sclx repeated start write to sspxcon2 write to sspxbuf occurs here at completion of start bit, hardware clears rsen bit 1st bit s bit set by hardware t brg t brg sdax = 1 , sdax = 1 , sclx (no change) sclx = 1 occurs here t brg t brg t brg and sets sspxif sr
pic16(l)f1946/1947 ds41414c-page 276 preliminary ? 2010-2011 microchip technology inc. 24.6.6 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 trans- mission. each bit of address/data will be shifted out onto the sdax pin after the falling edge of sclx is asserted. sclx is held low for one baud rate genera- tor rollover count (t brg ). data should be valid before sclx is released high. 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 prop- erly. the status of ack is written into the ackstat bit on the rising 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 24-27 ). 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 release 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 of the sspxcon2 register. following the falling edge of the ninth clock transmission of the address, the sspxif 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. 24.6.6.1 bf status flag in transmit mode, the bf bit of the sspxstat register is set when the cpu writes to sspxbuf and is cleared when all 8 bits are shifted out. 24.6.6.2 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 is set and the contents of the buffer are unchanged (the write does not occur). wcol must be cleared by software before the next transmission. 24.6.6.3 ackstat status flag in transmit mode, the ackstat bit of the sspxcon2 register is cleared when the slave has sent an acknowl- edge (ack = 0 ) and is set when the slave does not acknowledge (ack = 1 ). a slave sends an acknowl- edge when it has recognized its address (including a general call), or when the slave has properly received its data. 24.6.6.4 typical transmit sequence: 1. the user generates a start condition by setting the sen bit of the sspxcon2 register. 2. sspxif is set by hardware on completion of the start. 3. sspxif is cleared by software. 4. the msspx module will wait the required start time before any other operation takes place. 5. the user loads the sspxbuf with the slave address to transmit. 6. address is shifted out the sdax pin until all 8 bits are transmitted. transmission begins as soon as sspxbuf is written to. 7. the msspx module shifts in the ack bit from the slave device and writes its value into the ackstat bit of the sspxcon2 register. 8. the msspx module generates an interrupt at the end of the ninth clock cycle by setting the sspxif bit. 9. the user loads the sspxbuf with eight bits of data. 10. data is shifted out the sdax pin until all 8 bits are transmitted. 11. the msspx module shifts in the ack bit from the slave device and writes its value into the ackstat bit of the sspxcon2 register. 12. steps 8-11 are repeated for all transmitted data bytes. 13. the user generates a stop or restart condition by setting the pen or rsen bits of the sspxcon2 register. interrupt is generated once the stop/restart condition is complete.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 277 pic16(l)f1946/1947 figure 24-28: 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 by software service routine sspxbuf is written by software from sspx 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 by software sspxbuf written pen r/w cleared by software
pic16(l)f1946/1947 ds41414c-page 278 preliminary ? 2010-2011 microchip technology inc. 24.6.7 i 2 c master mode reception master mode reception is enabled by programming the receive enable bit, rcen bit of the sspxcon2 register. 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 msspx 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, acken bit of the sspxcon2 register. 24.6.7.1 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. 24.6.7.2 sspxov status flag in receive operation, the sspxov bit is set when 8 bits are received into the sspxsr and the bf flag bit is already set from a previous reception. 24.6.7.3 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 does not occur). 24.6.7.4 typical receive sequence: 1. the user generates a start condition by setting the sen bit of the sspxcon2 register. 2. sspxif is set by hardware on completion of the start. 3. sspxif is cleared by software. 4. user writes sspxbuf with the slave address to transmit and the r/w bit set. 5. address is shifted out the sdax pin until all 8 bits are transmitted. transmission begins as soon as sspxbuf is written to. 6. the msspx module shifts in the ack bit from the slave device and writes its value into the ackstat bit of the sspxcon2 register. 7. the msspx module generates an interrupt at the end of the ninth clock cycle by setting the sspxif bit. 8. user sets the rcen bit of the sspxcon2 regis- ter and the master clocks in a byte from the slave. 9. after the 8th falling edge of sclx, sspxif and bf are set. 10. master clears sspxif and reads the received byte from sspxuf, clears bf. 11. master sets ack value sent to slave in ackdt bit of the sspxcon2 register and initiates the ack by setting the acken bit. 12. masters ack is clocked out to the slave and sspxif is set. 13. user clears sspxif. 14. steps 8-13 are repeated for each received byte from the slave. 15. master sends a not ack or stop to end communication. note: the msspx module must be in an idle state before the rcen bit is set or the rcen bit will be disregarded.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 279 pic16(l)f1946/1947 figure 24-29: 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 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 by software start xmit sen = 0 sspxov sdax = 0 , sclx = 1 while cpu (sspxstat<0>) ack cleared by software cleared by software set sspxif interrupt at end of receive set p bit (sspxstat<4>) and sspxif cleared in software ack from master set sspxif at end set sspxif interrupt at end of acknowledge sequence set sspxif interrupt at end of acknow- ledge sequence of receive set acken, start acknowledge sequence sspxov is set because sspxbuf is still full 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 by software sdax = ackdt = 0 last bit is shifted into sspxsr and contents are unloaded into sspxbuf rcen master configured as a receiver by programming sspxcon2<3> (rcen = 1 ) rcen cleared automatically ack from master sdax = ackdt = 0 rcen cleared automatically
pic16(l)f1946/1947 ds41414c-page 280 preliminary ? 2010-2011 microchip technology inc. 24.6.8 acknowledge sequence timing an acknowledge sequence is enabled by setting the acknowledge sequence enable bit, acken bit of the sspxcon2 register. 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 generate 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 generator 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 generator counts for t brg . the sclx pin is then pulled low. following this, the acken bit is auto- matically cleared, the baud rate generator is turned off and the msspx module then goes into idle mode ( figure 24-29 ). 24.6.8.1 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 does not occur). 24.6.9 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 bit of the sspxcon2 register. 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 of the sspxstat register is set. a t brg later, the pen bit is cleared and the sspxif bit is set ( figure 24-30 ). 24.6.9.1 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 does not occur). figure 24-30: acknowledge sequen ce waveform 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
? 2010-2011 microchip technology inc. preliminary ds41414c-page 281 pic16(l)f1946/1947 figure 24-31: stop cond ition receive or transmit mode 24.6.10 sleep operation while in sleep mode, the i 2 c slave module can receive addresses or data and when an address match or complete byte transfer occurs, wake the processor from sleep (if the msspx interrupt is enabled). 24.6.11 effects of a reset a reset disables the msspx module and terminates the current transfer. 24.6.12 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 msspx module is disabled. control of the i 2 c bus may be taken when the p bit of the sspxstat register is set, or the bus is idle, with both the s and p bits clear. when the bus is busy, enabling the sspx 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 by 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 24.6.13 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 is ? 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 24-31 ). 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 ser- vices the bus collision interrupt service routine and if the i 2 c bus is free, the user can resume communica- tion by asserting a start condition. if a start, repeated start, stop or acknowledge condi- tion was in progress when the bus collision occurred, the condition is aborted, the sdax and sclx lines are deas- serted and the respective control bits in the sspxcon2 register are cleared. when the user services the bus col- lision interrupt service routine 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 deter- mination 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. 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 setup stop condition ack p t brg pen bit (sspxcon2<2>) is cleared by hardware and the sspxif bit is set
pic16(l)f1946/1947 ds41414c-page 282 preliminary ? 2010-2011 microchip technology inc. figure 24-32: 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 does not match what is driven bus collision has occurred. set bus collision interrupt (bclxif) by the master. by master data changes while sclx = 0
? 2010-2011 microchip technology inc. preliminary ds41414c-page 283 pic16(l)f1946/1947 24.6.13.1 bus collision during a start condition during a start condition, a bus collision occurs if: a) sdax or sclx are sampled low at the beginning of the start condition ( figure 24-32 ). b) sclx is sampled low before sdax is asserted low ( figure 24-33 ). 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 and ? the msspx module is reset to its idle state ( figure 24-32 ). the start condition begins with the sdax and sclx pins deasserted. when the sdax pin is sampled high, the baud rate generator is loaded and counts down. 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 24-34 ). 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 zero; 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 24-33: bus collision during st art condition (sdax only) note: the reason that bus collision is not a fac- tor 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 fol- lowing 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 sspx 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 by software sspxif and bclxif are cleared by software set bclxif, start condition. set bclxif.
pic16(l)f1946/1947 ds41414c-page 284 preliminary ? 2010-2011 microchip technology inc. figure 24-34: bus collision d uring start condition (sclx = 0 ) figure 24-35: brg reset due to sda arbitration 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 by 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 by 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
? 2010-2011 microchip technology inc. preliminary ds41414c-page 285 pic16(l)f1946/1947 24.6.13.2 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 low level to 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 releases sdax and the pin is allowed to float high, the brg is loaded with sspxadd and counts down to zero. 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 24-35 ). 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 24-36 . 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 24-36: bus collision during a repeat ed start condition (case 1) figure 24-37: bus collision during repeat ed 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 by software ? 0 ? ? 0 ? sdax sclx bclxif rsen s sspxif interrupt cleared by software sclx goes low before sdax, set bclxif. release sdax and sclx. t brg t brg ? 0 ?
pic16(l)f1946/1947 ds41414c-page 286 preliminary ? 2010-2011 microchip technology inc. 24.6.13.3 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 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 24-37 ). 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 24-38 ). figure 24-38: bus collision during a stop condition (case 1) figure 24-39: 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 ?
? 2010-2011 microchip technology inc. preliminary ds41414c-page 287 pic16(l)f1946/1947 table 24-3: summary of registers associated with i 2 c? operation name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 reset values on page intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie2 osfie c2ie c1ie eeie bclie lcdie c3ie ccp2ie (1) 95 pie4 (1) ? ? rc2ie tx2ie ? ? bcl2ie ssp2ie 97 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir2 osfif c2if c1if eeif bclif lcdif c3if ccp2if (1) 99 pir4 (1) ? ? rc2if tx2if ? ? bcl2if ssp2if 101 trisa trisa7 trisa6 trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 128 trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 131 sspxadd add<7:0> 295 sspxbuf msspx receive buffer/transmit register 245* sspxcon1 wcol sspov sspen ckp sspm<3:0> 291 sspxcon2 gcen ackstat ackdt acken rcen pen rsen sen 293 sspxcon3 acktim pcie scie boen sdaht sbcde ahen dhen 294 sspxmsk msk<7:0> 295 sspxstat smp cke d/a psr/w ua bf 289 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by the mssp module in i 2 c? mode. * page provides register information. note 1: pic16f1947 only.
pic16(l)f1946/1947 ds41414c-page 288 preliminary ? 2010-2011 microchip technology inc. 24.7 baud rate generator the msspx module has a baud rate generator avail- able for clock generation in both i 2 c and spi master modes. the baud rate generator (brg) reload value is placed in the sspxadd register ( register 24-6 ). when a write occurs to sspxbuf, the baud rate gen- erator will automatically begin counting down. once the given operation is complete, the internal clock will automatically stop counting and the clock pin will remain in its last state. an internal signal ?reload? in figure 24-39 triggers the value from sspxadd to be loaded into the brg counter. this occurs twice for each oscillation of the module clock line. the logic dictating when the reload signal is asserted depends on the mode the msspx is being operated in. table 24-4 demonstrates clock rates based on instruction cycles and the brg value loaded into sspxadd. equation 24-1: figure 24-40: baud rate genera tor block diagram table 24-4: msspx clock rate w/brg f clock f osc sspxadd 1 + ?? 4 ?? ------------------------------------------------- = note: values of 0x00, 0x01 and 0x02 are not valid for sspxadd when used as a baud rate generator for i 2 c. this is an implementation limitation. f osc f cy brg value f clock (2 rollovers of brg) 32 mhz 8 mhz 13h 400 khz (1) 32 mhz 8 mhz 19h 308 khz 32 mhz 8 mhz 4fh 100 khz 16 mhz 4 mhz 09h 400 khz (1) 16 mhz 4 mhz 0ch 308 khz 16 mhz 4 mhz 27h 100 khz 4 mhz 1 mhz 09h 100 khz note 1: the i 2 c interface does not conform to the 400 khz i 2 c specification (which applies to rates greater than 100 khz) in all details, but may be used with care where higher rates are required by the application. sspxm<3:0> brg down counter sspxclk f osc /2 sspxadd<7:0> sspxm<3:0> sclx reload control reload
? 2010-2011 microchip technology inc. preliminary ds41414c-page 289 pic16(l)f1946/1947 24.8 mssp control registers register 24-1: sspxstat: sspx status register r/w-0/0 r/w-0/0 r-0/0 r-0/0 r-0/0 r-0/0 r-0/0 r-0/0 smp cke d/a psr/w ua bf bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = val ue at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 smp: spi data input sample bit spi master mode: 1 = input data sampled at end of data output time 0 = input data sampled at middle of data output time spi slave mode: smp must be cleared when spi is used in slave mode in i 2 c master or slave mode: 1 = slew rate control disabled for standard speed mode (100 khz and 1 mhz) 0 = slew rate control enabled for high speed mode (400 khz) bit 6 cke: spi clock edge select bit (spi mode only) in spi master or slave mode: 1 = transmit occurs on transition from active to idle clock state 0 = transmit occurs on transition from idle to active clock state in i 2 c ? mode only: 1 = enable input logic so that thresholds are compliant with smbus specification 0 = disable smbus specific inputs bit 5 d/a : data/address bit (i 2 c mode only) 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 (i 2 c mode only. this bit is cleared when the msspx module is disabled, sspxen is cleared.) 1 = indicates that a stop bit has been detected last (this bit is ? 0 ? on reset) 0 = stop bit was not detected last bit 3 s: start bit (i 2 c mode only. this bit is cleared when the msspx module is disabled, sspxen is cleared.) 1 = indicates that a start bit has been detected last (this bit is ? 0 ? on reset) 0 = start bit was not detected last bit 2 r/w : read/write bit information (i 2 c mode only) 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. in i 2 c slave mode: 1 = read 0 = write in i 2 c master mode: 1 = transmit is in progress 0 = transmit is not in progress or-ing this bit with sen, rsen, pen, rcen or acken will indicate if the msspx is in idle mode. bit 1 ua: update address bit (10-bit i 2 c mode only) 1 = indicates that the user needs to update the address in the sspxadd register 0 = address does not need to be updated
pic16(l)f1946/1947 ds41414c-page 290 preliminary ? 2010-2011 microchip technology inc. bit 0 bf: buffer full status bit receive (spi and i 2 c modes): 1 = receive complete, sspxbuf is full 0 = receive not complete, sspxbuf is empty transmit (i 2 c mode only): 1 = data transmit in progress (does not include the ack and stop bits), sspxbuf is full 0 = data transmit complete (does not include the ack and stop bits), sspxbuf is empty register 24-1: sspxstat: sspx status register (continued)
? 2010-2011 microchip technology inc. preliminary ds41414c-page 291 pic16(l)f1946/1947 register 24-2: sspxcon1: ss px control register 1 r/c/hs-0/0 r/c/hs-0/0 r/w-0/0 r/w-0 /0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 wcol sspxov sspxen ckp sspxm<3:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = val ue at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared hs = bit is set by hardware c = user cleared bit 7 wcol: write collision detect bit master 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 0 = no collision slave mode: 1 = the sspxbuf register is written while it is still tran smitting the previous word (must be cleared in software) 0 = no collision bit 6 sspxov: receive overflow indicator bit (1) in spi mode: 1 = a new byte is received while the sspxbu f register is still holding the previous data. in case of overflow, the data in sspxsr is lost. overflow can only occur in slave mode. in slave mode, the user must read the sspxbuf, even if only transmitting data, to avoid setting overflow. in mast er mode, the overflow bit is not set since each new recep- tion (and transmission) is initiated by writing to the sspxbuf register (must be cleared in software). 0 = no overflow in i 2 c mode: 1 = a byte is received while the sspxbuf register is still holding the previous byte. sspxov is a ?don?t care? in transmit mode (must be cleared in software). 0 = no overflow bit 5 sspxen: synchronous serial port enable bit in both modes, when enabled, these pins must be properly configured as input or output in spi mode: 1 = enables serial port and configures sckx, sdox, sdix and ssx as the source of the serial port pins (2) 0 = disables serial port and configures these pins as i/o port pins in i 2 c mode: 1 = enables the serial port and configures the sdax and sclx pins as the source of the serial port pins (3) 0 = disables serial port and configures these pins as i/o port pins bit 4 ckp: clock polarity select bit in spi mode: 1 = idle state for clock is a high level 0 = idle state for clock is a low level in i 2 c slave mode: sclx release control 1 = enable clock 0 = holds clock low (clock stretch). (used to ensure data setup time.) in i 2 c master mode: unused in this mode
pic16(l)f1946/1947 ds41414c-page 292 preliminary ? 2010-2011 microchip technology inc. bit 3-0 sspxm<3:0>: synchronous serial port mode select bits 0000 = spi master mode, clock = f osc /4 0001 = spi master mode, clock = f osc /16 0010 = spi master mode, clock = f osc /64 0011 = spi master mode, clock = tmr2 output/2 0100 = spi slave mode, clock = sckx pin, ssx pin control enabled 0101 = spi slave mode, clock = sckx pin, ssx pin control disabled, ssx can be used as i/o pin 0110 = i 2 c slave mode, 7-bit address 0111 = i 2 c slave mode, 10-bit address 1000 = i 2 c master mode, clock = f osc / (4 * (sspxadd+1)) (4) 1001 = reserved 1010 = spi master mode, clock = f osc /(4 * (sspxadd+1)) (5) 1011 = i 2 c firmware controlled master mode (slave idle) 1100 = reserved 1101 = reserved 1110 = i 2 c slave mode, 7-bit address with start and stop bit interrupts enabled 1111 = i 2 c slave mode, 10-bit address with start and stop bit interrupts enabled 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 proper ly configured as input or output. 3: when enabled, the sdax and sclx pins must be configured as inputs. 4: sspxadd values of 0, 1 or 2 are not supported for i 2 c mode. 5: sspxadd value of ? 0 ? is not supported. use sspxm = 0000 instead. register 24-2: sspxcon1: sspx co ntrol register 1 (continued)
? 2010-2011 microchip technology inc. preliminary ds41414c-page 293 pic16(l)f1946/1947 register 24-3: sspxcon2: ss px control register 2 r/w-0/0 r-0/0 r/w-0/0 r/s/hs-0/0 r/s/hs- 0/0 r/s/hs-0/0 r/s/hs-0/0 r/w/hs-0/0 gcen ackstat ackdt acken rcen pen rsen sen bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared hc = cleared by hardware s = user set bit 7 gcen: general call enable bit (in i 2 c slave mode only) 1 = enable interrupt when a general call address (0x00 or 00h) is received in the sspxsr 0 = general call address disabled bit 6 ackstat: acknowledge status bit (in i 2 c mode only) 1 = acknowledge was not received 0 = acknowledge was received bit 5 ackdt: acknowledge data bit (in i 2 c mode only) in receive mode: value transmitted when the user initiates an acknowledge sequence at the end of a receive 1 = not acknowledge 0 = acknowledge bit 4 acken: acknowledge sequence enable bit (in i 2 c master mode only) in master receive mode: 1 = initiate acknowledge sequence on sdax and sclx pins, and transmit ackdt data bit. automatically cleared by hardware. 0 = acknowledge sequence idle bit 3 rcen: receive enable bit (in i 2 c master mode only) 1 = enables receive mode for i 2 c 0 = receive idle bit 2 pen: stop condition enable bit (in i 2 c master mode only) sckx release control: 1 = initiate stop condition on sdax and sclx pins. automatically cleared by hardware. 0 = stop condition idle bit 1 rsen: repeated start condition enabled bit (in i 2 c master mode only) 1 = initiate repeated start condition on sdax and sclx pins. automatically cleared by hardware. 0 = repeated start condition idle bit 0 sen: start condition enabled bit (in i 2 c master mode only) in master mode: 1 = initiate start condition on sdax and sclx pins. automatically cleared by hardware. 0 = start condition idle in slave mode: 1 = clock stretching is enabled for both slave transmit and slave receive (stretch enabled) 0 = clock stretching is disabled note 1: for bits acken, rcen, pen, rsen, sen: if the i 2 c module is not in the idle mode, this bit may not be set (no spooling) and the sspxbuf may not be written (or writes to the sspxbuf are disabled).
pic16(l)f1946/1947 ds41414c-page 294 preliminary ? 2010-2011 microchip technology inc. register 24-4: sspxcon3: ss px control register 3 r-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 acktim pcie scie boen sdaht sbcde ahen dhen bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 acktim: acknowledge time status bit (i 2 c mode only) (3) 1 = indicates the i 2 c bus is in an acknowledge sequence, set on 8 th falling edge of sclx clock 0 = not an acknowledge sequence, cleared on 9 th rising edge of sclx clock bit 6 pcie : stop condition interrupt enable bit (i 2 c mode only) 1 = enable interrupt on detection of stop condition 0 = stop detection interrupts are disabled (2) bit 5 scie : start condition interrupt enable bit (i 2 c mode only) 1 = enable interrupt on detection of start or restart conditions 0 = start detection interrupts are disabled (2) bit 4 boen: buffer overwrite enable bit in spi slave mode: (1) 1 = sspxbuf updates every time that a new data byte is shifted in ignoring the bf bit 0 = if new byte is received with bf bit of the sspxstat register already set, sspxov bit of the sspxcon1 register is set, and the buffer is not updated in i 2 c master mode and spi master mode: this bit is ignored. in i 2 c slave mode: 1 = sspxbuf is updated and ack is generated for a received address/data byte, ignoring the state of the sspxov bit only if the bf bit = 0 . 0 = sspxbuf is only updated when sspxov is clear bit 3 sdaht: sdax hold time selection bit (i 2 c mode only) 1 = minimum of 300 ns hold time on sdax after the falling edge of sclx 0 = minimum of 100 ns hold time on sdax after the falling edge of sclx bit 2 sbcde: slave mode bus collision detect enable bit (i 2 c slave mode only) if on the rising edge of sclx, sdax is sampled low when the module is outputting a high state, the bclxif bit of the pir2 register is set, and bus goes idle 1 = enable slave bus collision interrupts 0 = slave bus collision interrupts are disabled bit 1 ahen: address hold enable bit (i 2 c slave mode only) 1 = following the 8th falling edge of sclx for a matching received address byte; ckp bit of the sspxcon1 register will be cleared and the sclx will be held low. 0 = address holding is disabled bit 0 dhen: data hold enable bit (i 2 c slave mode only) 1 = following the 8th falling edge of sclx for a received data byte; slave hardware clears the ckp bit of the sspxcon1 register and sclx is held low. 0 = data holding is disabled note 1: for daisy-chained spi operation; allows the user to igno re all but the last received byte. sspxov is still set when a new byte is received and bf = 1 , but hardware continues to write the most recent byte to sspxbuf. 2: this bit has no effect in slave modes that start and stop condition detection is explicitly listed as enabled. 3: the acktim status bit is only active when the ahen bit or dhen bit is set.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 295 pic16(l)f1946/1947 register 24-5: sspxmsk: sspx mask register r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 r/w-1/1 msk<7:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-1 msk<7:1>: mask bits 1 = the received address bit n is compared to sspxadd to detect i 2 c address match 0 = the received address bit n is not used to detect i 2 c address match bit 0 msk<0>: mask bit for i 2 c slave mode, 10-bit address i 2 c slave mode, 10-bit address (sspxm<3:0> = 0111 or 1111 ): 1 = the received address bit 0 is compared to sspxadd<0> to detect i 2 c address match 0 = the received address bit 0 is not used to detect i 2 c address match i 2 c slave mode, 7-bit address, the bit is ignored register 24-6: sspxadd: msspx address and baud rate register (i 2 c mode) r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 add<7:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared master mode: bit 7-0 add<7:0>: baud rate clock divider bits sclx pin clock period = ((add<7:0> + 1) *4)/f osc 10-bit slave mode ? most significant address byte: bit 7-3 not used: unused for most significant address byte. bit state of this register is a ?don?t care?. bit pattern sent by master is fixed by i 2 c specification and must be equal to ? 11110 ?. however, those bits are compared by hardware and are not affected by the value in this register. bit 2-1 add<2:1>: two most significant bits of 10-bit address bit 0 not used: unused in this mode. bit state is a ?don?t care?. 10-bit slave mode ? least significant address byte: bit 7-0 add<7:0>: eight least significant bits of 10-bit address 7-bit slave mode: bit 7-1 add<7:1>: 7-bit address bit 0 not used: unused in this mode. bit state is a ?don?t care?.
pic16(l)f1946/1947 ds41414c-page 296 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 297 pic16(l)f1946/1947 25.0 enhanced universal synchronous asynchronous receiver transmitter (eusart) the enhanced universal synchronous asynchronous receiver transmitter (eusart) module is a serial i/o communications peripheral. it contains all the clock generators, shift registers and data buffers necessary to perform an input or output serial data transfer independent of device program execution. the eusart, also known as a serial communications interface (sci), can be configured as a full-duplex asynchronous system or half-duplex synchronous system. full-duplex mode is useful for communications with peripheral systems, such as crt terminals and personal computers. half-duplex synchronous mode is intended for communications with peripheral devices, such as a/d or d/a integrated circuits, serial eeproms or other microcontrollers. these devices typically do not have internal clocks for baud rate generation and require the external clock signal provided by a master synchronous device. the eusart module includes the following capabilities: ? full-duplex asynchronous transmit and receive ? two-character input buffer ? one-character output buffer ? programmable 8-bit or 9-bit character length ? address detection in 9-bit mode ? input buffer overrun error detection ? received character framing error detection ? half-duplex synchronous master ? half-duplex synchronous slave ? programmable clock and data polarity the eusart module implements the following additional features, making it ideally suited for use in local interconnect network (lin) bus systems: ? automatic detection and calibration of the baud rate ? wake-up on break reception ? 13-bit break character transmit block diagrams of the eusart transmitter and receiver are shown in figure 25-1 and figure 25-2 . figure 25-1: eusart transmi t block diagram note: the pic16f/lf/1946/47 devices have two eusarts. therefore, all information in this section refers to both eusart 1 and eusart 2. txxif txxie interrupt txen tx9d msb lsb data bus txxreg register transmit shift register (tsr) (8) 0 tx9 trmt txx/ckx pin pin buffer and control 8 spxbrgl spxbrgh brg16 f osc n n + 1 multiplier x4 x16 x64 sync 1x00 0 brgh x110 0 brg16 x101 0 baud rate generator ???
pic16(l)f1946/1947 ds41414c-page 298 preliminary ? 2010-2011 microchip technology inc. figure 25-2: eusart receiv e block diagram the operation of the eusart module is controlled through three registers: ? transmit status and control (txxsta) ? receive status and control (rcxsta) ? baud rate control (baudxcon) these registers are detailed in register 25-1 , register 25-2 and register 25-3 , respectively. for all modes of eusart operation, the tris control bits corresponding to the rxx/dtx and txx/ckx pins should be set to ? 1 ?. the eusart control will automatically reconfigure the pin from input to output, as needed. when the receiver or transmitter section is not enabled then the corresponding rxx/dtx or txx/ckx pin may be used for general purpose input and output. rxx/dtx pin pin buffer and control data recovery cren oerr ferr rsr register msb lsb rx9d rcxreg register fifo interrupt rcxif rcxie data bus 8 stop start (8) 7 1 0 rx9 ? ? ? spxbrgl spxbrgh brg16 rcidl f osc n n + 1 multiplier x4 x16 x64 sync 1x00 0 brgh x110 0 brg16 x101 0 baud rate generator
? 2010-2011 microchip technology inc. preliminary ds41414c-page 299 pic16(l)f1946/1947 25.1 eusart asynchronous mode the eusart transmits and receives data using the standard non-return-to-zero (nrz) format. nrz is implemented with two levels: a v oh mark state which represents a ? 1 ? data bit, and a v ol space state which represents a ? 0 ? data bit. nrz refers to the fact that consecutively transmitted data bits of the same value stay at the output level of that bit without returning to a neutral level between each bit transmission. an nrz transmission port idles in the mark state. each character transmission consists of one start bit followed by eight or nine data bits and is always terminated by one or more stop bits. the start bit is always a space and the stop bits are always marks. the most common data format is 8 bits. each transmitted bit persists for a period of 1/(baud rate). an on-chip dedicated 8-bit/16-bit baud rate generator is used to derive standard baud rate frequencies from the system oscillator. see table 25-5 for examples of baud rate configurations. the eusart transmits and receives the lsb first. the eusart?s transmitter and receiver are functionally independent, but share the same data format and baud rate. parity is not supported by the hardware, but can be implemented in software and stored as the ninth data bit. 25.1.1 eusart asynchronous transmitter the eusart transmitter block diagram is shown in figure 25-1 . the heart of the transmitter is the serial transmit shift register (tsr), which is not directly accessible by software. the tsr obtains its data from the transmit buffer, which is the txxreg register. 25.1.1.1 enabling the transmitter the eusart transmitter is enabled for asynchronous operations by configuring the following three control bits: ?txen = 1 ? sync = 0 ? spen = 1 all other eusart control bits are assumed to be in their default state. setting the txen bit of the txxsta register enables the transmitter circuitry of the eusart. clearing the sync bit of the txxsta register configures the eusart for asynchronous operation. setting the spen bit of the rcsta register enables the eusart and automatically configures the txx/ckx i/o pin as an output. if the txx/ckx pin is shared with an analog peripheral, the analog i/o function must be disabled by clearing the corresponding ansel bit. 25.1.1.2 transmitting data a transmission is initiated by writing a character to the txxreg register. if this is the first character, or the previous character has been completely flushed from the tsr, the data in the txxreg is immediately transferred to the tsr register. if the tsr still contains all or part of a previous character, the new character data is held in the txxreg until the stop bit of the previous character has been transmitted. the pending character in the txxreg is then transferred to the tsr in one t cy immediately following the stop bit transmission. the transmission of the start bit, data bits and stop bit sequence commences immediately following the transfer of the data to the tsr from the txxreg. 25.1.1.3 transmit data polarity the polarity of the transmit data can be controlled with the sckp bit of the baudxcon register. the default state of this bit is ? 0 ? which selects high true transmit idle and data bits. setting the sckp bit to ? 1 ? will invert the transmit data resulting in low true idle and data bits. the sckp bit controls transmit data polarity only in asynchronous mode. in synchronous mode the sckp bit has a different function. 25.1.1.4 transmit interrupt flag the txxif interrupt flag bit of the pir1/pir3 register is set whenever the eusart transmitter is enabled and no character is being held for transmission in the txxreg. in other words, the txxif bit is only clear when the tsr is busy with a character and a new character has been queued for transmission in the txxreg. the txxif flag bit is not cleared immediately upon writing txxreg. txxif becomes valid in the second instruction cycle following the write execution. polling txxif immediately following the txxreg write will return invalid results. the txxif bit is read-only, it cannot be set or cleared by software. the txxif interrupt can be enabled by setting the txxie interrupt enable bit of the pie1/pie3 register. however, the txxif flag bit will be set whenever the txxreg is empty, regardless of the state of txxie enable bit. to use interrupts when transmitting data, set the txxie bit only when there is more data to send. clear the txxie interrupt enable bit upon writing the last character of the transmission to the txxreg. note: the txxif transmitter interrupt flag is set when the txen enable bit is set.
pic16(l)f1946/1947 ds41414c-page 300 preliminary ? 2010-2011 microchip technology inc. 25.1.1.5 tsr status the trmt bit of the txxsta register indicates the status of the tsr register. this is a read-only bit. the trmt bit is set when the tsr register is empty and is cleared when a character is transferred to the tsr register from the txxreg. the trmt bit remains clear until all bits have been shifted out of the tsr register. no interrupt logic is tied to this bit, so the user needs to poll this bit to determine the tsr status. 25.1.1.6 transmitting 9-bit characters the eusart supports 9-bit character transmissions. when the tx9 bit of the txxsta register is set the eusart will shift 9 bits out for each character transmit- ted. the tx9d bit of the txxsta register is the ninth, and most significant, data bit. when transmitting 9-bit data, the tx9d data bit must be written before writing the 8 least significant bits into the txxreg. all nine bits of data will be transferred to the tsr shift register immediately after the txxreg is written. a special 9-bit address mode is available for use with multiple receivers. see section 25.1.2.7 ?address detection? for more information on the address mode. 25.1.1.7 asynchronous transmission set-up: 1. initialize the spxbrgh:spxbrgl register pair and the brgh and brg16 bits to achieve the desired baud rate (see section 25.4 ?eusart baud rate generator (brg)? ). 2. set the rxx/dtx and txx/ckx tris controls to ? 1 ?. 3. enable the asynchronous serial port by clearing the sync bit and setting the spen bit. 4. if 9-bit transmission is desired, set the tx9 control bit. a set ninth data bit will indicate that the 8 least significant data bits are an address when the receiver is set for address detection. 5. set the sckp control bit if inverted transmit data polarity is desired. 6. enable the transmission by setting the txen control bit. this will cause the txxif interrupt bit to be set. 7. if interrupts are desired, set the txxie interrupt enable bit. an interrupt will occur immediately provided that the gie and peie bits of the intcon register are also set. 8. if 9-bit transmission is selected, the ninth bit should be loaded into the tx9d data bit. 9. load 8-bit data into the txxreg register. this will start the transmission. figure 25-3: asynchronous transmission note: the tsr register is not mapped in data memory, so it is not available to the user. word 1 stop bit word 1 transmit shift reg start bit bit 0 bit 1 bit 7/8 write to txxreg word 1 brg output (shift clock) txx/ckx txxif bit (transmit buffer reg. empty flag) trmt bit (transmit shift reg. empty flag) 1 t cy pin
? 2010-2011 microchip technology inc. preliminary ds41414c-page 301 pic16(l)f1946/1947 figure 25-4: asynchronous transmiss ion (back-to-back) transmit shift reg write to txxreg brg output (shift clock) txx/ckx txxif bit (interrupt reg. flag) trmt bit (transmit shift reg. empty flag) word 1 word 2 word 1 word 2 start bit 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 pin table 25-1: registers associated with asynchronous transmission name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page baud1con abdovf rcidl ? sckp brg16 ? wue abden 309 baud2con abdovf rcidl ? sckp brg16 ? wue abden 309 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie4 ? ? rc2ie tx2ie ? ? bcl2ie ssp2ie 97 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir4 ? ? rc2if tx2if ? ? bcl2if ssp2if 97 rc1sta spen rx9 sren cren adden ferr oerr rx9d 308 rc2sta spen rx9 sren cren adden ferr oerr rx9d 308 sp1brgl eusart1 baud rate generator, low byte 310* sp1brgh eusart1 baud rate generator, high byte 310* sp2brgl eusart2 baud rate generator, low byte 310* sp2brgh eusart2 baud rate generator, high byte 310* tx1reg eusart1 transmit register 299* tx1sta csrc tx9 txen sync sendb brgh trmt tx9d 306 tx2reg eusart2 transmit register 299* tx2sta csrc tx9 txen sync sendb brgh trmt tx9d 306 legend: ? = unimplemented locations, read as ? 0 ?. shaded bits are not used for asynchronous transmission. * page provides register information.
pic16(l)f1946/1947 ds41414c-page 302 preliminary ? 2010-2011 microchip technology inc. 25.1.2 eusart asynchronous receiver the asynchronous mode would typically be used in rs-232 systems. the receiver block diagram is shown in figure 25-2 . the data is received on the rxx/dtx pin and drives the data recovery block. the data recovery block is actually a high-speed shifter operating at 16 times the baud rate, whereas the serial receive shift register (rsr) operates at the bit rate. when all 8 or 9 bits of the character have been shifted in, they are immediately transferred to a two character first-in-first-out (fifo) memory. the fifo buffering allows reception of two complete characters and the start of a third character before software must start servicing the eusart receiver. the fifo and rsr registers are not directly accessible by software. access to the received data is via the rcxreg register. 25.1.2.1 enabling the receiver the eusart receiver is enabled for asynchronous operation by configuring the following three control bits: ? cren = 1 ? sync = 0 ? spen = 1 all other eusart control bits are assumed to be in their default state. setting the cren bit of the rcxsta register enables the receiver circuitry of the eusart. clearing the sync bit of the txxsta register configures the eusart for asynchronous operation. setting the spen bit of the rcxsta register enables the eusart. the programmer must set the corresponding tris bit to configure the rxx/dtx i/o pin as an input. if the rxx/dtx pin is shared with an analog peripheral the analog i/o function must be disabled by clearing the corresponding ansel bit. 25.1.2.2 receiving data the receiver data recovery circuit initiates character reception on the falling edge of the first bit. the first bit, also known as the start bit, is always a zero. the data recovery circuit counts one-half bit time to the center of the start bit and verifies that the bit is still a zero. if it is not a zero then the data recovery circuit aborts character reception, without generating an error, and resumes looking for the falling edge of the start bit. if the start bit zero verification succeeds then the data recovery circuit counts a full bit time to the center of the next bit. the bit is then sampled by a majority detect circuit and the resulting ? 0 ? or ? 1 ? is shifted into the rsr. this repeats until all data bits have been sampled and shifted into the rsr. one final bit time is measured and the level sampled. this is the stop bit, which is always a ? 1 ?. if the data recovery circuit samples a ? 0 ? in the stop bit position then a framing error is set for this character, otherwise the framing error is cleared for this character. see section 25.1.2.4 ?receive framing error? for more information on framing errors. immediately after all data bits and the stop bit have been received, the character in the rsr is transferred to the eusart receive fifo and the rcxif interrupt flag bit of the pir1/pir3 register is set. the top charac- ter in the fifo is transferred out of the fifo by reading the rcxreg register. note 1: if the rx/dt function is on an analog pin, the corresponding ansel bit must be cleared for the receiver to function. note: if the receive fifo is overrun, no additional characters will be received until the overrun condition is cleared. see section 25.1.2.5 ?receive overrun error? for more information on overrun errors.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 303 pic16(l)f1946/1947 25.1.2.3 receive interrupts the rcxif interrupt flag bit of the pir1/pir3 register is set whenever the eusart receiver is enabled and there is an unread character in the receive fifo. the rcxif interrupt flag bit is read-only, it cannot be set or cleared by software. rcxif interrupts are enabled by setting the following bits: ? rcxie interrupt enable bit of the pie1/pie3 register ? peie peripheral interrupt enable bit of the intcon register ? gie global interrupt enable bit of the intcon register the rcxif interrupt flag bit will be set when there is an unread character in the fifo, regardless of the state of interrupt enable bits. 25.1.2.4 receive framing error each character in the receive fifo buffer has a corresponding framing error status bit. a framing error indicates that a stop bit was not seen at the expected time. the framing error status is accessed via the ferr bit of the rcxsta register. the ferr bit represents the status of the top unread character in the receive fifo. therefore, the ferr bit must be read before reading the rcxreg. the ferr bit is read-only and only applies to the top unread character in the receive fifo. a framing error (ferr = 1 ) does not preclude reception of additional characters. it is not necessary to clear the ferr bit. reading the next character from the fifo buffer will advance the fifo to the next character and the next corresponding framing error. the ferr bit can be forced clear by clearing the spen bit of the rcxsta register which resets the eusart. clearing the cren bit of the rcxsta register does not affect the ferr bit. a framing error by itself does not generate an interrupt. 25.1.2.5 receive overrun error the receive fifo buffer can hold two characters. an overrun error will be generated if a third character, in its entirety, is received before the fifo is accessed. when this happens the oerr bit of the rcxsta register is set. the characters already in the fifo buffer can be read but no additional characters will be received until the error is cleared. the error must be cleared by either clearing the cren bit of the rcxsta register or by resetting the eusart by clearing the spen bit of the rcxsta register. 25.1.2.6 receiving 9-bit characters the eusart supports 9-bit character reception. when the rx9 bit of the rcxsta register is set, the eusart will shift 9 bits into the rsr for each character received. the rx9d bit of the rcxsta register is the ninth and most significant data bit of the top unread character in the receive fifo. when reading 9-bit data from the receive fifo buffer, the rx9d data bit must be read before reading the 8 least significant bits from the rcxreg. 25.1.2.7 address detection a special address detection mode is available for use when multiple receivers share the same transmission line, such as in rs-485 systems. address detection is enabled by setting the adden bit of the rcxsta register. address detection requires 9-bit character reception. when address detection is enabled, only characters with the ninth data bit set will be transferred to the receive fifo buffer, thereby setting the rcxif interrupt bit. all other characters will be ignored. upon receiving an address character, user software determines if the address matches its own. upon address match, user software must disable address detection by clearing the adden bit before the next stop bit occurs. when user software detects the end of the message, determined by the message protocol used, software places the receiver back into the address detection mode by setting the adden bit. note: if all receive characters in the receive fifo have framing errors, repeated reads of the rcxreg will not clear the ferr bit.
pic16(l)f1946/1947 ds41414c-page 304 preliminary ? 2010-2011 microchip technology inc. 25.1.2.8 asynchronous reception set-up: 1. initialize the spxbrgh:spxbrgl register pair and the brgh and brg16 bits to achieve the desired baud rate (see section 25.4 ?eusart baud rate generator (brg)? ). 2. set the rxx/dtx and txx/ckx tris controls to ? 1 ?. 3. enable the serial port by setting the spen bit and the rxx/dtx pin tris bit. the sync bit must be clear for asynchronous operation. 4. if interrupts are desired, set the rcxie interrupt enable bit and set the gie and peie bits of the intcon register. 5. if 9-bit reception is desired, set the rx9 bit. 6. enable reception by setting the cren bit. 7. the rcxif interrupt flag bit will be set when a character is transferred from the rsr to the receive buffer. an interrupt will be generated if the rcxie interrupt enable bit was also set. 8. read the rcxsta register to get the error flags and, if 9-bit data reception is enabled, the ninth data bit. 9. get the received 8 least significant data bits from the receive buffer by reading the rcxreg register. 10. if an overrun occurred, clear the oerr flag by clearing the cren receiver enable bit. 25.1.2.9 9-bit address detection mode set-up this mode would typically be used in rs-485 systems. to set up an asynchronous reception with address detect enable: 1. initialize the spxbrgh, spxbrgl register pair and the brgh and brg16 bits to achieve the desired baud rate (see section 25.4 ?eusart baud rate generator (brg)? ). 2. set the rxx/dtx and txx/ckx tris controls to ? 1 ?. 3. enable the serial port by setting the spen bit. the sync bit must be clear for asynchronous operation. 4. if interrupts are desired, set the rcxie interrupt enable bit and set the gie and peie bits of the intcon register. 5. enable 9-bit reception by setting the rx9 bit. 6. enable address detection by setting the adden bit. 7. enable reception by setting the cren bit. 8. the rcxif interrupt flag bit will be set when a character with the ninth bit set is transferred from the rsr to the receive buffer. an interrupt will be generated if the rcxie interrupt enable bit was also set. 9. read the rcxsta register to get the error flags. the ninth data bit will always be set. 10. get the received 8 least significant data bits from the receive buffer by reading the rcxreg register. software determines if this is the device?s address. 11. if an overrun occurred, clear the oerr flag by clearing the cren receiver enable bit. 12. if the device has been addressed, clear the adden bit to allow all received data into the receive buffer and generate interrupts. figure 25-5: 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/dtx pin reg rcv buffer reg rcv shift read rcv buffer reg rcxreg rcxif (interrupt flag) oerr bit cren word 1 rcxreg word 2 rcxreg stop bit note: this timing diagram shows three words appearing on the rxx/dtx input. the rcxreg (receive buffer) is read after the third word, causing the oerr (overrun) bit to be set. rcidl
? 2010-2011 microchip technology inc. preliminary ds41414c-page 305 pic16(l)f1946/1947 table 25-2: registers associated with asynchronous reception name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page baud1con abdovf rcidl ? sckp brg16 ? wue abden 309 baud2con abdovf rcidl ? sckp brg16 ? wue abden 309 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie4 ? ? rc2ie tx2ie ? ? bcl2ie ssp2ie 97 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir4 ? ? rc2if tx2if ? ? bcl2if ssp2if 97 rc1reg eusart1 receive register 302* rc1sta spen rx9 sren cren adden ferr oerr rx9d 308 rc2reg eusart2 receive register 302* rc2sta spen rx9 sren cren adden ferr oerr rx9d 308 sp1brgl eusart1 baud rate generator, low byte 310* sp1brgh eusart1 baud rate generator, high byte 310* sp2brgl eusart2 baud rate generator, low byte 310* sp2brgh eusart2 baud rate generator, high byte 310* trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 134 tx1sta csrc tx9 txen sync sendb brgh trmt tx9d 306 tx2sta csrc tx9 txen sync sendb brgh trmt tx9d 306 legend: ? = unimplemented locations, read as ? 0 ?. shaded bits are not used for asynchronous reception. * page provides register information.
pic16(l)f1946/1947 ds41414c-page 306 preliminary ? 2010-2011 microchip technology inc. 25.2 clock accuracy with asynchronous operation the factory calibrates the internal oscillator block output (hfintosc). however, the hfintosc frequency may drift as v dd or temperature changes, and this directly affects the asynchronous baud rate. two methods may be used to adjust the baud rate clock, but both require a reference clock source of some kind. the first (preferred) method uses the osctune register to adjust the hfintosc output. adjusting the value in the osctune register allows for fine resolution changes to the system clock source. see section 5.2 ?clock source types? for more information. the other method adjusts the value in the baud rate generator. this can be done automatically with the auto-baud detect feature (see section 25.4.1 ?auto-baud detect? ). there may not be fine enough resolution when adjusting the baud rate generator to compensate for a gradual change in the peripheral clock frequency. 25.3 eusart control registers register 25-1: txxsta: 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 : don?t 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 enabled 0 = transmit 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 completed synchronous mode : don?t care
? 2010-2011 microchip technology inc. preliminary ds41414c-page 307 pic16(l)f1946/1947 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 empty 0 = tsr full bit 0 tx9d: ninth bit of transmit data can be address/data bit or a parity bit. note 1: sren/cren overrides txen in sync mode. register 25-1: txxsta: transmit status and control register (continued)
pic16(l)f1946/1947 ds41414c-page 308 preliminary ? 2010-2011 microchip technology inc. register 25-2: rcxsta: receiv e status 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 enabled (configures rxx/dtx and txx/ckx pins as serial port pins) 0 = serial port 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 : don?t care synchronous mode ? master : 1 = enables single receive 0 = disables single receive this bit is cleared after reception is complete. synchronous mode ? slave don?t 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, enable interrupt and load the receive buffer when rsr<8> is set 0 = disables address detection, all bytes are received and ninth bit can be used as parity bit asynchronous mode 8-bit (rx9 = 0 ) : don?t care bit 2 ferr: framing error bit 1 = framing error (can be updated by reading rcxreg register and receive next 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: ninth bit of received data this can be address/data bit or a parity bit and must be calculated by user firmware.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 309 pic16(l)f1946/1947 register 25-3: baudxcon: baud rate control register r-0/0 r-1/1 u-0 r/w-0/0 r/w-0/0 u-0 r/w-0/0 r/w-0/0 abdovf rcidl ? sckp brg16 ? wue abden bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 abdovf: auto-baud detect overflow bit asynchronous mode : 1 = auto-baud timer overflowed 0 = auto-baud timer did not overflow synchronous mode : don?t care bit 6 rcidl : receive idle flag bit asynchronous mode : 1 = receiver is idle 0 = start bit has been received and the receiver is receiving synchronous mode : don?t care bit 5 unimplemented: read as ? 0 ? bit 4 sckp : synchronous clock polarity select bit asynchronous mode : 1 = transmit inverted data to the txx/ckx pin 0 = transmit non-inverted data to the txx/ckx pin synchronous mode : 1 = data is clocked on rising edge of the clock 0 = data is clocked on falling edge of the clock bit 3 brg16: 16-bit baud rate generator bit 1 = 16-bit baud rate generator is used 0 = 8-bit baud rate generator is used bit 2 unimplemented: read as ? 0 ? bit 1 wue: wake-up enable bit asynchronous mode : 1 = receiver is waiting for a falling edge. no character will be received, byte rcif will be set. wue will automatically clear after rcif is set. 0 = receiver is operating normally synchronous mode : don?t care bit 0 abden : auto-baud detect enable bit asynchronous mode : 1 = auto-baud detect mode is enabled (clears when auto-baud is complete) 0 = auto-baud detect mode is disabled synchronous mode : don?t care
pic16(l)f1946/1947 ds41414c-page 310 preliminary ? 2010-2011 microchip technology inc. 25.4 eusart baud rate generator (brg) the baud rate generator (brg) is an 8-bit or 16-bit timer that is dedicated to the support of both the asynchronous and synchronous eusart operation. by default, the brg operates in 8-bit mode. setting the brg16 bit of the baudxcon register selects 16-bit mode. the spxbrgh:spxbrgl register pair determines the period of the free running baud rate timer. in asynchronous mode the multiplier of the baud rate period is determined by both the brgh bit of the txxsta register and the brg16 bit of the baudxcon register. in synchronous mode, the brgh bit is ignored. example 25-1 provides a sample calculation for deter- mining the desired baud rate, actual baud rate, and baud rate% error. typical baud rates and error values for various asynchronous modes have been computed for your convenience and are shown in table 25-5 . it may be advantageous to use the high baud rate (brgh = 1 ), or the 16-bit brg (brg16 = 1 ) to reduce the baud rate error. the 16-bit brg mode is used to achieve slow baud rates for fast oscillator frequencies. writing a new value to the spxbrgh, spxbrgl register pair causes the brg timer to be reset (or cleared). this ensures that the brg does not wait for a timer overflow before outputting the new baud rate. if the system clock is changed during an active receive operation, a receive error or data loss may result. to avoid this problem, check the status of the rcidl bit to make sure that the receive operation is idle before changing the system clock. example 25-1: calculating baud rate error for a device with f osc of 16 mhz, desired baud rate of 9600, asynchronous mode, 8-bit brg: solving for spxbrgh:spxbrgl: spxbrgh: spxbrgl f osc desired baud rate --------------------------------------------- 64 --------------------------------------------- 1 ? = desired baud rate f osc 64 [spxbrgh:spxbrg] 1 + ?? ------------------------------------------------------------------------- - = 16000000 9600 ----------------------- - 64 ----------------------- -1 ? = 25.042 ?? 25 == actualbaudrate 16000000 64 25 1 + ?? -------------------------- - = 9615 = calc. baud rate desired baud rate ? desired baud rate -------------------------------------------------------------------------------------------- 9615 9600 ? ?? 9600 ---------------------------------- 0 . 1 6 % == baud rate % error = table 25-3: 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 = don?t care, n = value of spxbrgh, spxbrgl register pair
? 2010-2011 microchip technology inc. preliminary ds41414c-page 311 pic16(l)f1946/1947 table 25-4: registers associated with baud rate generator name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 reset values on page baud1con abdovf rcidl ? sckp brg16 ? wue abden 309 baud2con abdovf rcidl ? sckp brg16 ? wue abden 309 rc1sta spen rx9 sren cren adden ferr oerr rx9d 308 rc2sta spen rx9 sren cren adden ferr oerr rx9d 308 sp1brgl eusart1 baud rate generator, low byte 310* sp1brgh eusart1 baud rate generator, high byte 310* sp2brgl eusart2 baud rate generator, low byte 310* sp2brgh eusart2 baud rate generator, high byte 310* tx1sta csrc tx9 txen sync sendb brgh trmt tx9d 306 tx2sta csrc tx9 txen sync sendb brgh trmt tx9d 306 legend: ? = unimplemented, read as ? 0 ?. shaded bits are not used by the brg. * page provides register information. table 25-5: baud rates for asynchronous modes baud rate sync = 0 , brgh = 0 , brg16 = 0 f osc = 32.000 mhz f osc = 18.432 mhz f osc = 16.000 mhz f osc = 11.0592 mhz actual rate % error spxbrgl value (decimal) actual rate % error spxbrgl value (decimal) actual rate % error spxbrgl value (decimal) actual rate % error spxbrgl value (decimal) 300?? ? ?? ? ?? ? ?? ? 1200 ?? ? 1200 0.00 239 1202 0.16 207 1200 0.00 143 2400 2404 0.16 207 2400 0.00 119 2404 0.16 103 2400 0.00 71 9600 9615 0.16 51 9600 0.00 29 9615 0.16 25 9600 0.00 17 10417 10417 0.00 47 10286 -1.26 27 10417 0.00 23 10165 -2.42 16 19.2k 19.23k 0.16 25 19.20k 0.00 14 19.23k 0.16 12 19.20k 0.00 8 57.6k 55.55k -3.55 3 57.60k 0.00 7 ?? ? 57.60k 0.00 2 115.2k ? ? ? ? ? ? ? ? ? ? ? ? baud rate sync = 0 , brgh = 0 , brg16 = 0 f osc = 8.000 mhz f osc = 4.000 mhz f osc = 3.6864 mhz f osc = 1.000 mhz actual rate % error spxbrgl value (decimal) actual rate % error spxbrgl value (decimal) actual rate % error spxbrgl value (decimal) actual rate % error spxbrgl value (decimal) 300 ? ? ? 300 0.16 207 300 0.00 191 300 0.16 51 1200 1202 0.16 103 1202 0.16 51 1200 0.00 47 1202 0.16 12 2400 2404 0.16 51 2404 0.16 25 2400 0.00 23 ? ? ? 9600 9615 0.16 12 ? ? ? 9600 0.00 5 ? ? ? 10417 10417 0.00 11 10417 0.00 5 ? ? ? ? ? ? 19.2k ? ? ? ? ? ? 19.20k 0.00 2 ? ? ? 57.6k ? ? ? ? ? ? 57.60k 0.00 0 ? ? ? 115.2k ? ? ? ? ? ? ? ? ? ? ? ?
pic16(l)f1946/1947 ds41414c-page 312 preliminary ? 2010-2011 microchip technology inc. baud rate sync = 0 , brgh = 1 , brg16 = 0 f osc = 32.000 mhz f osc = 18.432 mhz f osc = 16.000 mhz f osc = 11.0592 mhz actual rate % error spxbrgl value (decimal) actual rate % error spxbrgl value (decimal) actual rate % error spxbrgl value (decimal) actual rate % error spxbrgl value (decimal) 300 ?? ? ?? ? ?? ? ?? ? 1200 ? ? ? ? ? ? ? ? ? ? ? ? 2400 ? ? ? ? ? ? ?? ? ?? ? 9600 9615 0.16 207 9600 0.00 119 9615 0.16 103 9600 0.00 71 10417 10417 0.00 191 10378 -0.37 110 10417 0.00 95 10473 0.53 65 19.2k 19.23k 0.16 103 19.20k 0.00 59 19.23k 0.16 51 19.20k 0.00 35 57.6k 57.14k -0.79 34 57.60k 0.00 19 58.82k 2.12 16 57.60k 0.00 11 115.2k 117.64k 2.12 16 115.2k 0.00 9 111.1k -3.55 8 115.2k 0.00 5 baud rate sync = 0 , brgh = 1 , brg16 = 0 f osc = 8.000 mhz f osc = 4.000 mhz f osc = 3.6864 mhz f osc = 1.000 mhz actual rate % error spxbrgl value (decimal) actual rate % error spxbrgl value (decimal) actual rate % error spxbrgl value (decimal) actual rate % error spxbrgl value (decimal) 300 ?? ? ? ? ? ? ? ? 300 0.16 207 1200 ? ? ? 1202 0.16 207 1200 0.00 191 1202 0.16 51 2400 2404 0.16 207 2404 0.16 103 2400 0.00 95 2404 0.16 25 9600 9615 0.16 51 9615 0.16 25 9600 0.00 23 ? ? ? 10417 10417 0.00 47 10417 0.00 23 10473 0.53 21 10417 0.00 5 19.2k 19231 0.16 25 19.23k 0.16 12 19.2k 0.00 11 ? ? ? 57.6k 55556 -3.55 8 ? ? ? 57.60k 0.00 3 ? ? ? 115.2k ? ? ? ? ? ? 115.2k 0.00 1 ? ? ? baud rate sync = 0 , brgh = 0 , brg16 = 1 f osc = 32.000 mhz f osc = 18.432 mhz f osc = 16.000 mhz f osc = 11.0592 mhz actual rate % error spxbrgh: spxbrgl (decimal) actual rate % error spxbrgh: spxbrgl (decimal) actual rate % error spxbrgh: spxbrgl (decimal) actual rate % error spxbrgh: spxbrgl (decimal) 300 300.0 0.00 6666 300.0 0.00 3839 300.03 0.01 3332 300.0 0.00 2303 1200 1200.1 0.02 3332 1200 0.00 959 1200.5 0.04 832 1200 0.00 575 2400 2401 -0.04 832 2400 0.00 479 2398 -0.08 416 2400 0.00 287 9600 9615 0.16 207 9600 0.00 119 9615 0.16 103 9600 0.00 71 10417 10417 0.00 191 10378 -0.37 110 10417 0.00 95 10473 0.53 65 19.2k 19.23k 0.16 103 19.20k 0.00 59 19.23k 0.16 51 19.20k 0.00 35 57.6k 57.14k -0.79 34 57.60k 0.00 19 58.82k 2.12 16 57.60k 0.00 11 115.2k 117.6k 2.12 16 115.2k 0.00 9 111.11k -3.55 8 115.2k 0.00 5 table 25-5: baud rates for asynchronous modes (continued)
? 2010-2011 microchip technology inc. preliminary ds41414c-page 313 pic16(l)f1946/1947 baud rate sync = 0 , brgh = 0 , brg16 = 1 f osc = 8.000 mhz f osc = 4.000 mhz f osc = 3.6864 mhz f osc = 1.000 mhz actual rate % error spxbrgh: spxbrgl (decimal) actual rate % error spxbrgh: spxbrgl (decimal) actual rate % error spxbrgh: spxbrgl (decimal) actual rate % error spxbrgh: spxbrgl (decimal) 300 299.9 -0.02 1666 300.1 0.04 832 300.0 0.00 767 300.5 0.16 207 1200 1199 -0.08 416 1202 0.16 207 1200 0.00 191 1202 0.16 51 2400 2404 0.16 207 2404 0.16 103 2400 0.00 95 2404 0.16 25 9600 9615 0.16 51 9615 0.16 25 9600 0.00 23 ? ? ? 10417 10417 0.00 47 10417 0.00 23 10473 0.53 21 10417 0.00 5 19.2k 19.23k 0.16 25 19.23k 0.16 12 19.20k 0.00 11 ? ? ? 57.6k 55556 -3.55 8 ? ? ? 57.60k 0.00 3 ? ? ? 115.2k ? ? ? ? ? ? 115.2k 0.00 1 ? ? ? baud rate sync = 0 , brgh = 1 , brg16 = 1 or sync = 1 , brg16 = 1 f osc = 32.000 mhz f osc = 18.432 mhz f osc = 16.000 mhz f osc = 11.0592 mhz actual rate % error spxbrgh: spxbrgl (decimal) actual rate % error spxbrgh: spxbrgl (decimal) actual rate % error spxbrgh: spxbrgl (decimal) actual rate % error spxbrgh: spxbrgl (decimal) 300 300 0.00 26666 300.0 0.00 15359 300.0 0.00 13332 300.0 0.00 9215 1200 1200 0.00 6666 1200 0.00 3839 1200.1 0.01 3332 1200 0.00 2303 2400 2400 0.01 3332 2400 0.00 1919 2399.5 -0.02 1666 2400 0.00 1151 9600 9604 0.04 832 9600 0.00 479 9592 -0.08 416 9600 0.00 287 10417 10417 0.00 767 10425 0.08 441 10417 0.00 383 10433 0.16 264 19.2k 19.18k -0.08 416 19.20k 0.00 239 19.23k 0.16 207 19.20k 0.00 143 57.6k 57.55k -0.08 138 57.60k 0.00 79 57.97k 0.64 68 57.60k 0.00 47 115.2k 115.9 0.64 68 115.2k 0.00 39 114.29k -0.79 34 115.2k 0.00 23 baud rate sync = 0 , brgh = 1 , brg16 = 1 or sync = 1 , brg16 = 1 f osc = 8.000 mhz f osc = 4.000 mhz f osc = 3.6864 mhz f osc = 1.000 mhz actual rate % error spxbrgh: spxbrgl (decimal) actual rate % error spxbrgh: spxbrgl (decimal) actual rate % error spxbrgh: spxbrgl (decimal) actual rate % error spxbrgh: spxbrgl (decimal) 300 300.0 0.00 6666 300.0 0.01 3332 300.0 0.00 3071 300.1 0.04 832 1200 1200 -0.02 1666 1200 0.04 832 1200 0.00 767 1202 0.16 207 2400 2401 0.04 832 2398 0.08 416 2400 0.00 383 2404 0.16 103 9600 9615 0.16 207 9615 0.16 103 9600 0.00 95 9615 0.16 25 10417 10417 0.00 191 10417 0.00 95 10473 0.53 87 10417 0.00 23 19.2k 19.23k 0.16 103 19.23k 0.16 51 19.20k 0.00 47 19.23k 0.16 12 57.6k 57.14k -0.79 34 58.82k 2.12 16 57.60k 0.00 15 ? ? ? 115.2k 117.6k 2.12 16 111.1k -3.55 8 115.2k 0.00 7 ? ? ? table 25-5: baud rates for asynchronous modes (continued)
pic16(l)f1946/1947 ds41414c-page 314 preliminary ? 2010-2011 microchip technology inc. 25.4.1 auto-baud detect the eusart module supports automatic detection and calibration of the baud rate. in the auto-baud 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. the baud rate generator is used to time the period of a received 55h (ascii ?u?) which is the sync character for the lin bus. the unique feature of this character is that it has five rising edges including the stop bit edge. setting the abden bit of the baudxcon register starts the auto-baud calibration sequence ( figure 25.4.2 ). while the abd sequence takes place, the eusart state machine is held in idle. on the first rising edge of the receive line, after the start bit, the spxbrgl begins counting up using the brg counter clock as shown in tab l e 2 5- 6 . the fifth rising edge will occur on the rxx/dtx pin at the end of the eighth bit period. at that time, an accumulated value totaling the proper brg period is left in the spxbrgh:spxbrgl register pair, the abden bit is automatically cleared, and the rcxif interrupt flag is set. a read operation on the rcxreg needs to be performed to clear the rcxif interrupt. rcxreg content should be discarded. when calibrating for modes that do not use the spxbrgh register the user can verify that the spxbrgl register did not overflow by checking for 00h in the spxbrgh register. the brg auto-baud clock is determined by the brg16 and brgh bits as shown in table 25-6 . during abd, both the spxbrgh and spxbrgl registers are used as a 16-bit counter, independent of the brg16 bit setting. while calibrating the baud rate period, the spxbrgh and spxbrgl registers are clocked at 1/8th the brg base clock rate. the resulting byte measurement is the average bit time when clocked at full speed. figure 25-6: automatic baud rate calibration note 1: if the wue bit is set with the abden bit, auto-baud detection will occur on the byte following the break character (see section 25.4.3 ?auto-wake-up on break? ). 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 frequency and eusart baud rates are not possible. 3: during the auto-baud process, the auto-baud counter starts counting at 1. upon completion of the auto-baud sequence, to achieve maximum accu- racy, subtract 1 from the spxbrgh:spx- brgl register pair. table 25-6: brg counter clock rates brg16 brgh brg base clock brg abd clock 00 f osc /64 f osc /512 01 f osc /16 f osc /128 10 f osc /16 f osc /128 11 f osc /4 f osc /32 note: during the abd sequence, spxbrgl and spxbrgh registers are both used as a 16-bit counter, independent of brg16 setting. brg value rxx/dtx pin abden bit rcxif bit bit 0 bit 1 (interrupt) read rcxreg 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 stop bit edge #5 001ch note 1: the abd sequence requires the eusart module to be configured in asynchronous mode. spxbrgl xxh 1ch spxbrgh xxh 00h rcidl
? 2010-2011 microchip technology inc. preliminary ds41414c-page 315 pic16(l)f1946/1947 25.4.2 auto-baud overflow during the course of automatic baud detection, the abdovf bit of the baudxcon register will be set if the baud rate counter overflows before the fifth rising edge is detected on the rx pin. the abdovf bit indicates that the counter has exceeded the maximum count that can fit in the 16 bits of the spxbrgh:spxbrgl register pair. after the abdovf has been set, the coun- ter continues to count until the fifth rising edge is detected on the rxx/dtx pin. upon detecting the fifth rxx/dtx edge, the hardware will set the rcxif inter- rupt flag and clear the abden bit of the baudxcon register. the rcxif flag can be subsequently cleared by reading the rcxreg. the abdovf flag can be cleared by software directly. to terminate the auto-baud process before the rcxif flag is set, clear the abden bit then clear the abdovf bit. the abdovf bit will remain set if the abden bit is not cleared first. 25.4.3 auto-wake-up on break during sleep mode, all clocks to the eusart are suspended. because of this, the baud rate generator is inactive and a proper character reception cannot be performed. the auto-wake-up feature allows the controller to wake-up due to activity on the rxx/dtx line. this feature is available only in asynchronous mode. the auto-wake-up feature is enabled by setting the wue bit of the baudxcon register. once set, the normal 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 protocol.) the eusart module generates an rcxif interrupt coincident with the wake-up event. the interrupt is generated synchronously to the q clocks in normal cpu operating modes ( figure 25-7 ), and asynchronously if the device is in sleep mode ( figure 25-8 ). the interrupt condition is cleared by reading the rcxreg register. the wue bit is automatically cleared by the low-to-high transition on the rxx line at the end of the break. this signals to the user that the break event is over. at this point, the eusart module is in idle mode waiting to receive the next character. 25.4.3.1 special considerations break character to avoid character errors or character fragments during a wake-up event, the wake-up character must be all zeros. when the wake-up is enabled the function works independent of the low time on the data stream. if the wue bit is set and a valid non-zero character is received, the low time from the start bit to the first rising edge will be interpreted as the wake-up event. the remaining bits in the character will be received as a fragmented character and subsequent characters can result in framing or overrun errors. therefore, the initial character in the transmission must be all ? 0 ?s. this must be 10 or more bit times, 13-bit times recommended for lin bus, or any number of bit times for standard rs-232 devices. oscillator startup time oscillator start-up time must be considered, especially in applications using oscillators with longer start-up intervals (i.e., lp, xt or hs/pll 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. wue bit the wake-up event causes a receive interrupt by setting the rcxif bit. the wue bit is cleared by hardware by a rising edge on rxx/dtx. the interrupt condition is then cleared by software by reading the rcxreg register and discarding its contents. to ensure that no actual data is lost, check the rcidl bit to verify that a receive operation is not in process before setting the wue bit. if a receive operation is not occurring, the wue bit may then be set just prior to entering the sleep mode.
pic16(l)f1946/1947 ds41414c-page 316 preliminary ? 2010-2011 microchip technology inc. figure 25-7: auto-wake-up bit (wue) timing during normal operation figure 25-8: auto-wake-up bit (wue) timings during sleep 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 q1 q2 q3 q4 q1 q2 q3 q4 q1 q2 q3 q4 osc1 wue bit rxx/dtx line rcxif bit set by user auto cleared cleared due to user read of rcxreg note 1: the eusart remains in idle while the wue bit is set. q1 q2 q3 q4 q1q2 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 rxx/dtx line rcxif bit set by user auto cleared cleared due to user read of rcxreg sleep command executed note 1 note 1: if the wake-up event requires long oscillator warm-up time, the automatic clearing of the wue bit can occur while the stposc signal is still active. 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
? 2010-2011 microchip technology inc. preliminary ds41414c-page 317 pic16(l)f1946/1947 25.4.4 break character sequence the eusart module has the capability of sending the special break character sequences that are required by the lin bus standard. a break character consists of a start bit, followed by 12 ? 0 ? bits and a stop bit. to send a break character, set the sendb and txen bits of the txxsta register. the break character trans- mission is then initiated by a write to the txxreg. the value of data written to txxreg 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 specification). the trmt bit of the txxsta register indicates when the transmit operation is active or idle, just as it does during normal transmission. see figure 25-9 for the timing of the break character sequence. 25.4.4.1 break and sync transmit sequence the following sequence will start a message frame header made up of a break, followed by an auto-baud sync byte. this sequence is typical of a lin bus master. 1. configure the eusart for the desired mode. 2. set the txen and sendb bits to enable the break sequence. 3. load the txxreg with a dummy character to initiate transmission (the value is ignored). 4. write ?55h? to txxreg to load the sync charac- ter into the transmit fifo buffer. 5. after the break has been sent, the sendb bit is reset by hardware and the sync character is then transmitted. when the txxreg becomes empty, as indicated by the txxif, the next data byte can be written to txxreg. 25.4.5 receiving a break character the enhanced eusart module can receive a break character in two ways. the first method to detect a break character uses the ferr bit of the rcxsta register and the received data as indicated by rcxreg. the baud rate generator is assumed to have been initialized to the expected baud rate. a break character has been received when; ? rcxif bit is set ? ferr bit is set ? rcxreg = 00h the second method uses the auto-wake-up feature described in section 25.4.3 ?auto-wake-up on break? . 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 detect feature. for both methods, the user can set the abden bit of the baudxcon register before placing the eusart in sleep mode. figure 25-9: send break character sequence write to txxreg dummy write brg output (shift clock) start bit bit 0 bit 1 bit 11 stop bit break txxif bit (transmit interrupt flag) txx/ckx (pin) trmt bit (transmit shift reg. empty flag) sendb (send break control bit) sendb sampled here auto cleared
pic16(l)f1946/1947 ds41414c-page 318 preliminary ? 2010-2011 microchip technology inc. 25.5 eusart synchronous mode synchronous serial communications are typically used in systems with a single master and one or more slaves. the master device contains the necessary circuitry for baud rate generation and supplies the clock for all devices in the system. slave devices can take advantage of the master clock by eliminating the internal clock generation circuitry. there are two signal lines in synchronous mode: a bidirectional data line and a clock line. slaves use the external clock supplied by the master to shift the serial data into and out of their respective receive and transmit shift registers. since the data line is bidirectional, synchronous operation is half-duplex only. half-duplex refers to the fact that master and slave devices can receive and transmit data but not both simultaneously. the eusart can operate as either a master or slave device. start and stop bits are not used in synchronous transmissions. 25.5.1 synchronous master mode the following bits are used to configure the eusart for synchronous master operation: ? sync = 1 ? csrc = 1 ? sren = 0 (for transmit); sren = 1 (for receive) ? cren = 0 (for transmit); cren = 1 (for receive) ? spen = 1 setting the sync bit of the txxsta register configures the device for synchronous operation. setting the csrc bit of the txxsta register configures the device as a master. clearing the sren and cren bits of the rcxsta register ensures that the device is in the transmit mode, otherwise the device will be configured to receive. setting the spen bit of the rcxsta register enables the eusart. if the rxx/dtx or txx/ckx pins are shared with an analog peripheral the analog i/o functions must be disabled by clearing the corresponding ansel bits. the tris bits corresponding to the rxx/dtx and txx/ckx pins should be set. 25.5.1.1 master clock synchronous data transfers use a separate clock line, which is synchronous with the data. a device configured as a master transmits the clock on the txx/ckx line. the txx/ckx pin output driver is automatically enabled when the eusart is configured for synchronous transmit or receive operation. serial data bits change on the leading edge to ensure they are valid at the trailing edge of each clock. one clock cycle is generated for each data bit. only as many clock cycles are generated as there are data bits. 25.5.1.2 clock polarity a clock polarity option is provided for microwire compatibility. clock polarity is selected with the sckp bit of the baudxcon register. setting the sckp bit sets the clock idle state as high. when the sckp bit is set, the data changes on the falling edge of each clock and is sampled on the rising edge of each clock. clearing the sckp bit sets the idle state as low. when the sckp bit is cleared, the data changes on the rising edge of each clock and is sampled on the falling edge of each clock. 25.5.1.3 synchronous master transmission data is transferred out of the device on the rxx/dtx pin. the rxx/dtx and txx/ckx pin output drivers are automatically enabled when the eusart is configured for synchronous master transmit operation. a transmission is initiated by writing a character to the txxreg register. if the tsr still contains all or part of a previous character the new character data is held in the txxreg until the last bit of the previous character has been transmitted. if this is the first character, or the previous character has been completely flushed from the tsr, the data in the txxreg is immediately trans- ferred to the tsr. the transmission of the character commences immediately following the transfer of the data to the tsr from the txxreg. each data bit changes on the leading edge of the master clock and remains valid until the subsequent leading clock edge. note: the tsr register is not mapped in data memory, so it is not available to the user.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 319 pic16(l)f1946/1947 25.5.1.4 synchronous master transmission set-up: 1. initialize the spxbrgh, spxbrgl register pair and the brgh and brg16 bits to achieve the desired baud rate (see section 25.4 ?eusart baud rate generator (brg)? ). 2. set the rxx/dtx and txx/ckx tris controls to ? 1 ?. 3. enable the synchronous master serial port by setting bits sync, spen and csrc. set the tris bits corresponding to the rxx/dtx and txx/ckx i/o pins. 4. disable receive mode by clearing bits sren and cren. 5. enable transmit mode by setting the txen bit. 6. if 9-bit transmission is desired, set the tx9 bit. 7. if interrupts are desired, set the txxie, gie and peie interrupt enable bits. 8. if 9-bit transmission is selected, the ninth bit should be loaded in the tx9d bit. 9. start transmission by loading data to the txxreg register. figure 25-10: synchronous transmission figure 25-11: synchronous transmis sion (through txen) bit 0 bit 1 bit 7 word 1 bit 2 bit 0 bit 1 bit 7 rxx/dtx write to txxreg reg txxif bit (interrupt flag) txen bit ? 1 ? ? 1 ? word 2 trmt bit write word 1 write word 2 note: sync master mode, spxbrgl = 0 , continuous transmission of two 8-bit words. pin txx/ckx pin txx/ckx pin (sckp = 0 ) (sckp = 1 ) rxx/dtx pin txx/ckx pin write to txxreg reg txxif bit trmt bit bit 0 bit 1 bit 2 bit 6 bit 7 txen bit
pic16(l)f1946/1947 ds41414c-page 320 preliminary ? 2010-2011 microchip technology inc. table 25-7: registers associated wi th synchronous master transmission name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page baud1con abdovf rcidl ? sckp brg16 ? wue abden 309 baud2con abdovf rcidl ? sckp brg16 ? wue abden 309 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie4 ? ? rc2ie tx2ie ? ? bcl2ie ssp2ie 97 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir4 ? ? rc2if tx2if ? ? bcl2if ssp2if 97 rc1sta spen rx9 sren cren adden ferr oerr rx9d 308 rc2sta spen rx9 sren cren adden ferr oerr rx9d 308 sp1brgl eusart1 baud rate generator, low byte 310* sp1brgh eusart1 baud rate generator, high byte 310* sp2brgl eusart2 baud rate generator, low byte 310* sp2brgh eusart2 baud rate generator, high byte 310* trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 134 tx1reg eusart1 transmit register 299* tx1sta csrc tx9 txen sync sendb brgh trmt tx9d 306 tx2reg eusart2 transmit register 299* tx2sta csrc tx9 txen sync sendb brgh trmt tx9d 306 legend: ? = unimplemented locations, read as ? 0 ?. shaded bits are not used for synchronous master transmission. * page provides register information.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 321 pic16(l)f1946/1947 25.5.1.5 synchronous master reception data is received at the rxx/dtx pin. the rxx/dtx pin output driver must be disabled by setting the corresponding tris bits when the eusart is configured for synchronous master receive operation. in synchronous mode, reception is enabled by setting either the single receive enable bit (sren of the rcxsta register) or the continuous receive enable bit (cren of the rcxsta register). when sren is set and cren is clear, only as many clock cycles are generated as there are data bits in a single character. the sren bit is automatically cleared at the completion of one character. when cren is set, clocks are continuously generated until cren is cleared. if cren is cleared in the middle of a character the ck clock stops immediately and the partial charac- ter is discarded. if sren and cren are both set, then sren is cleared at the completion of the first character and cren takes precedence. to initiate reception, set either sren or cren. data is sampled at the rxx/dtx pin on the trailing edge of the txx/ckx clock pin and is shifted into the receive shift register (rsr). when a complete character is received into the rsr, the rcxif bit is set and the character is automatically transferred to the two character receive fifo. the least significant eight bits of the top character in the receive fifo are available in rcxreg. the rcxif bit remains set as long as there are un-read characters in the receive fifo. 25.5.1.6 slave clock synchronous data transfers use a separate clock line, which is synchronous with the data. a device configured as a slave receives the clock on the txx/ckx line. the txx/ckx pin output driver must be disabled by setting the associated tris bit when the device is configured for synchronous slave transmit or receive operation. serial data bits change on the leading edge to ensure they are valid at the trailing edge of each clock. one data bit is transferred for each clock cycle. only as many clock cycles should be received as there are data bits. 25.5.1.7 receive overrun error the receive fifo buffer can hold two characters. an overrun error will be generated if a third character, in its entirety, is received before rcxreg is read to access the fifo. when this happens the oerr bit of the rcxsta register is set. previous data in the fifo will not be overwritten. the two characters in the fifo buffer can be read, however, no additional characters will be received until the error is cleared. the oerr bit can only be cleared by clearing the overrun condition. if the overrun error occurred when the sren bit is set and cren is clear then the error is cleared by reading rcxreg. if the overrun occurred when the cren bit is set then the error condition is cleared by either clearing the cren bit of the rcxsta register or by clearing the spen bit which resets the eusart. 25.5.1.8 receiving 9-bit characters the eusart supports 9-bit character reception. when the rx9 bit of the rcxsta register is set the eusart will shift 9-bits into the rsr for each character received. the rx9d bit of the rcxsta register is the ninth, and most significant, data bit of the top unread character in the receive fifo. when reading 9-bit data from the receive fifo buffer, the rx9d data bit must be read before reading the 8 least significant bits from the rcxreg. 25.5.1.9 synchronous master reception set-up: 1. initialize the spxbrgh, spxbrgl register pair for the appropriate baud rate. set or clear the brgh and brg16 bits, as required, to achieve the desired baud rate. 2. set the rxx/dtx and txx/ckx tris controls to ? 1 ?. 3. enable the synchronous master serial port by setting bits sync, spen and csrc. disable rxx/dtx and txx/ckx output drivers by setting the corresponding tris bits. 4. ensure bits cren and sren are clear. 5. if using interrupts, set the gie and peie bits of the intcon register and set rcxie. 6. if 9-bit reception is desired, set bit rx9. 7. start reception by setting the sren bit or for continuous reception, set the cren bit. 8. interrupt flag bit rcxif will be set when recep- tion of a character is complete. an interrupt will be generated if the enable bit rcxie was set. 9. read the rcxsta register to get the ninth bit (if enabled) and determine if any error occurred during reception. 10. read the 8-bit received data by reading the rcxreg register. 11. if an overrun error occurs, clear the error by either clearing the cren bit of the rcxsta register or by clearing the spen bit which resets the eusart.
pic16(l)f1946/1947 ds41414c-page 322 preliminary ? 2010-2011 microchip technology inc. figure 25-12: synchronous reception (master mode, sren) cren bit rxx/dtx write to bit sren sren bit rcxif bit (interrupt) read rcxreg ? 0 ? bit 0 bit 1 bit 2 bit 3 bit 4 bit 5 bit 6 bit 7 ? 0 ? note: timing diagram demonstrates sync master mode with bit sren = 1 and bit brgh = 0 . txx/ckx pin txx/ckx pin pin (sckp = 0 ) (sckp = 1 ) table 25-8: registers associated with synchronous master reception name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page baud1con abdovf rcidl ? sckp brg16 ? wue abden 309 baud2con abdovf rcidl ? sckp brg16 ? wue abden 309 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie4 ? ? rc2ie tx2ie ? ? bcl2ie ssp2ie 97 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir4 ? ? rc2if tx2if ? ? bcl2if ssp2if 97 rc1reg eusart1 receive register 302* rc1sta spen rx9 sren cren adden ferr oerr rx9d 308 rc2reg eusart2 receive register 302* rc2sta spen rx9 sren cren adden ferr oerr rx9d 308 sp1brgl eusart1 baud rate generator, low byte 310* sp1brgh eusart1 baud rate generator, high byte 310* sp2brgl eusart2 baud rate generator, low byte 310* sp2brgh eusart2 baud rate generator, high byte 310* tx1sta csrc tx9 txen sync sendb brgh trmt tx9d 306 tx2sta csrc tx9 txen sync sendb brgh trmt tx9d 306 legend: ? = unimplemented locations, read as ? 0 ?. shaded bits are not used for synchronous master reception. * page provides register information.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 323 pic16(l)f1946/1947 25.5.2 synchronous slave mode the following bits are used to configure the eusart for synchronous slave operation: ? sync = 1 ? csrc = 0 ? sren = 0 (for transmit); sren = 1 (for receive) ? cren = 0 (for transmit); cren = 1 (for receive) ? spen = 1 setting the sync bit of the txxsta register configures the device for synchronous operation. clearing the csrc bit of the txxsta register configures the device as a slave. clearing the sren and cren bits of the rcxsta register ensures that the device is in the transmit mode, otherwise the device will be configured to receive. setting the spen bit of the rcxsta register enables the eusart. if the rxx/dtx or txx/ckx pins are shared with an analog peripheral the analog i/o functions must be disabled by clearing the corresponding ansel bits. rxx/dtx and txx/ckx pin output drivers must be disabled by setting the corresponding tris bits. 25.5.2.1 eusart synchronous slave transmit the operation of the synchronous master and slave modes are identical (see section 25.5.1.3 ?synchronous master transmission? ) , except in the case of the sleep mode. if two words are written to the txxreg and then the sleep instruction is executed, the following will occur: 1. the first character will immediately transfer to the tsr register and transmit. 2. the second word will remain in txxreg register. 3. the txxif bit will not be set. 4. after the first character has been shifted out of tsr, the txxreg register will transfer the second character to the tsr and the txxif bit will now be set. 5. if the peie and txxie bits are set, the interrupt will wake the device from sleep and execute the next instruction. if the gie bit is also set, the program will call the interrupt service routine. 25.5.2.2 synchronous slave transmission set-up: 1. set the sync and spen bits and clear the csrc bit. 2. set the rxx/dtx and txx/ckx tris controls to ? 1 ?. 3. clear the cren and sren bits. 4. if using interrupts, ensure that the gie and peie bits of the intcon register are set and set the txxie bit. 5. if 9-bit transmission is desired, set the tx9 bit. 6. enable transmission by setting the txen bit. 7. if 9-bit transmission is selected, insert the most significant bit into the tx9d bit. 8. start transmission by writing the least significant 8 bits to the txxreg register.
pic16(l)f1946/1947 ds41414c-page 324 preliminary ? 2010-2011 microchip technology inc. table 25-9: registers associated with synchronous slave transmission name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page baud1con abdovf rcidl ? sckp brg16 ? wue abden 309 baud2con abdovf rcidl ? sckp brg16 ? wue abden 309 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie4 ? ? rc2ie tx2ie ? ? bcl2ie ssp2ie 97 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir4 ? ? rc2if tx2if ? ? bcl2if ssp2if 97 rc1sta spen rx9 sren cren adden ferr oerr rx9d 308 rc2sta spen rx9 sren cren adden ferr oerr rx9d 308 sp1brgl eusart1 baud rate generator, low byte 310* sp1brgh eusart1 baud rate generator, high byte 310* sp2brgl eusart2 baud rate generator, low byte 310* sp2brgh eusart2 baud rate generator, high byte 310* trisc trisc7 trisc6 trisc5 trisc4 trisc3 trisc2 trisc1 trisc0 134 tx1reg eusart1 transmit register 299* tx1sta csrc tx9 txen sync sendb brgh trmt tx9d 306 tx2reg eusart2 transmit register 299* tx2sta csrc tx9 txen sync sendb brgh trmt tx9d 306 legend: ? = unimplemented locations, read as ? 0 ?. shaded bits are not used for synchronous slave transmission. * page provides register information.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 325 pic16(l)f1946/1947 25.5.2.3 eusart synchronous slave reception the operation of the synchronous master and slave modes is identical ( section 25.5.1.5 ?synchronous master reception? ), with the following exceptions: ? sleep ? cren bit is always set, therefore the receiver is never idle ? sren bit, which is a ?don?t care? in slave mode a character may be received while in sleep mode by setting the cren bit prior to entering sleep. once the word is received, the rsr register will transfer the data to the rcxreg register. if the rcxie enable bit is set, the interrupt generated will wake the device from sleep and execute the next instruction. if the gie bit is also set, the program will branch to the interrupt vector. 25.5.2.4 synchronous slave reception set-up: 1. set the sync and spen bits and clear the csrc bit. 2. set the rxx/dtx and txx/ckx tris controls to ? 1 ?. 3. if using interrupts, ensure that the gie and peie bits of the intcon register are set and set the rcxie bit. 4. if 9-bit reception is desired, set the rx9 bit. 5. set the cren bit to enable reception. 6. the rcxif bit will be set when reception is complete. an interrupt will be generated if the rcxie bit was set. 7. if 9-bit mode is enabled, retrieve the most significant bit from the rx9d bit of the rcxsta register. 8. retrieve the 8 least significant bits from the receive fifo by reading the rcxreg register. 9. if an overrun error occurs, clear the error by either clearing the cren bit of the rcxsta register or by clearing the spen bit which resets the eusart. table 25-10: registers associated with synchronous slave reception name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page baud1con abdovf rcidl ? sckp brg16 ? wue abden 309 baud2con abdovf rcidl ? sckp brg16 ? wue abden 309 intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 pie1 tmr1gie adie rcie txie sspie ccp1ie tmr2ie tmr1ie 94 pie4 ? ? rc2ie tx2ie ? ? bcl2ie ssp2ie 97 pir1 tmr1gif adif rcif txif sspif ccp1if tmr2if tmr1if 98 pir4 ? ? rc2if tx2if ? ? bcl2if ssp2if 97 rc1reg eusart1 receive register 302* rc1sta spen rx9 sren cren adden ferr oerr rx9d 308 rc2reg eusart2 receive register 302* rc2sta spen rx9 sren cren adden ferr oerr rx9d 308 sp1brgl eusart1 baud rate generator, low byte 310* sp1brgh eusart1 baud rate generator, high byte 310* sp2brgl eusart2 baud rate generator, low byte 310* sp2brgh eusart2 baud rate generator, high byte 310* tx1sta csrc tx9 txen sync sendb brgh trmt tx9d 306 tx2sta csrc tx9 txen sync sendb brgh trmt tx9d 306 legend: ? = unimplemented locations, read as ? 0 ?. shaded bits are not used for synchronous slave reception. * page provides register information.
pic16(l)f1946/1947 ds41414c-page 326 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 327 pic16(l)f1946/1947 26.0 capacitive sensing (cps) module the capacitive sensing (cps) module allows for an interaction with an end user without a mechanical interface. in a typical application, the cps module is attached to a pad on a printed circuit board (pcb), which is electrically isolated from the end user. when the end user places their finger over the pcb pad, a capacitive load is added, causing a frequency shift in the cps module. the cps module requires software and at least one timer resource to determine the change in frequency. key features of this module include: ? analog mux for monitoring multiple inputs ? capacitive sensing oscillator ? multiple power modes ? high power range with variable voltage references ? multiple timer resources ? software control ? operation during sleep figure 26-1: capacitive sensing block diagram note 1: if cpson = 0 , disabling capacitive sensing, no channel is selected. tmr0cs cps0 cps1 cps2 cps3 cps4 cps5 cps6 cps7 cps8 cps9 cps10 cpsch<3:0> capacitive sensing oscillator cpsosc cpson cpsrng<1:0> tmr0 0 1 set tmr0if overflow t0xcs 0 1 t0cki cpsout cps11 cps12 cps13 cps14 cps15 cpsclk f osc /4 timer0 module cpson (1) t1cs<1:0> t1osc/ t1cki tmr1h:tmr1l en t1gsel<1:0> timer1 gate control logic t1g f osc f osc /4 timer1 module syncc1out syncc2out 0 1 int. ref. fvr dac ref+ ref- cpsrm 0 1 cps16
pic16(l)f1946/1947 ds41414c-page 328 preliminary ? 2010-2011 microchip technology inc. figure 26-2: capacitive sensing oscillator block diagram 0 1 v dd cpsclk oscillator module cpsx sq r + - + - note 1: module enable and power mode selections are not shown. 2: comparators remain active in noise detection mode. (2) (1) (1) (2) 0 1 internal references fvr dac cpsrm analog pin ref- ref+
? 2010-2011 microchip technology inc. preliminary ds41414c-page 329 pic16(l)f1946/1947 26.1 analog mux the cps module can monitor up to 16 inputs. the capacitive sensing inputs are defined as cps<15:0>. to determine if a frequency change has occurred the user must: ? select the appropriate cps pin by setting the cpsch<4:0> bits of the cpscon1 register. ? set the corresponding ansel bit. ? set the corresponding tris bit. ? run the software algorithm. selection of the cpsx pin while the module is enabled will cause the capacitive sensing oscillator to be on the cpsx pin. failure to set the corresponding ansel and tris bits can cause the capacitive sensing oscillator to stop, leading to false frequency readings. 26.2 capacitive sensing oscillator the capacitive sensing oscillator consists of a constant current source and a constant current sink, to produce a triangle waveform. the cpsout bit of the cpscon0 register shows the status of the capacitive sensing oscillator, whether it is a sinking or sourcing current. the oscillator is designed to drive a capacitive load (single pcb pad) and at the same time, be a clock source to either timer0 or timer1. the oscillator has three different current settings as defined by cpsrng<1:0> of the cpscon0 register. the different current settings for the oscillator serve two purposes: ? maximize the number of counts in a timer for a fixed time base. ? maximize the count differential in the timer during a change in frequency. 26.2.1 voltage references the capacitive sensing oscillator uses voltage refer- ences to provide two voltage thresholds for oscillation. the upper voltage threshold is referred to as ref+ and the lower voltage threshold is referred to as ref-. the user can elect to use fixed voltage references, which are internal to the capacitive sensing oscillator, or variable voltage references, which are supplied by the fixed voltage reference (fvr) module and the digital-to-analog converter (dac) module. when the fixed voltage references are used, the v ss voltage determines the lower threshold level (ref-) and the v dd voltage determines the upper threshold level (ref+). when the variable voltage references are used, the dac voltage determines the lower threshold level (ref-) and the fvr voltage determines the upper threshold level (ref+). an advantage of using these ref- erence sources is that oscillation frequency remains constant with changes in v dd . different oscillation frequencies can be obtained through the use of these variable voltage references. the more the upper voltage reference level is lowered and the more the lower voltage reference level is raised, the higher the capacitive sensing oscillator frequency becomes. selection between the voltage references is controlled by the cpsrm bit of the cpscon0 register. setting this bit selects the variable voltage references and clearing this bit selects the fixed voltage references. please see section 14.0 ?fixed voltage reference (fvr)? and section 17.0 ?digital-to-analog converter (dac) module? for more information on configuring the variable voltage levels.
pic16(l)f1946/1947 ds41414c-page 330 preliminary ? 2010-2011 microchip technology inc. 26.2.2 power modes the capacitive sensing oscillator can operate in one of seven different power modes. the power modes are separated into two ranges; the low range and the high range. when the oscillator?s low range is selected, the fixed internal voltage references of the capacitive sensing oscillator are being used. when the oscillator?s high range is selected, the variable voltage references supplied by the fvr and dac modules are being used. selection between the voltage references is controlled by the cpsrm bit of the cpscon0 register. see section 26.2.1 ?voltage references? for more information. within each range there are three distinct power modes; low, medium and high. current consumption is dependent upon the range and mode selected. selecting power modes within each range is accomplished by configuring the cpsrng <1:0> bits in the cpscon0 register. see table 26-1 for proper power mode selection. the remaining mode is a noise detection mode that resides within the high range. the noise detection mode is unique in that it disables the sinking and sourc- ing of current on the analog pin but leaves the rest of the oscillator circuitry active. this reduces the oscilla- tion frequency on the analog pin to zero and also greatly reduces the current consumed by the oscillator module. when noise is introduced onto the pin, the oscillator is driven at the frequency determined by the noise. this produces a detectable signal at the comparator output, indicating the presence of activity on the pin. figure 26-2 shows a more detailed drawing of the current sources and comparat ors associated with the oscillator. table 26-1: power mode selection 26.2.3 timer resources to measure the change in frequency of the capacitive sensing oscillator, a fixed time base is required. for the period of the fixed time base, the capacitive sensing oscillator is used to clock either timer0 or timer1. the frequency of the capacitive sensing oscillator is equal to the number of counts in the timer divided by the period of the fixed time base. 26.2.4 fixed time base to measure the frequency of the capacitive sensing oscillator, a fixed time base is required. any timer resource or software loop can be used to establish the fixed time base. it is up to the end user to determine the method in which the fixed time base is generated. 26.2.4.1 timer0 to select timer0 as the timer resource for the cps module: ? set the t0xcs bit of the cpscon0 register. ? clear the tmr0cs bit of the option register. when timer0 is chosen as the timer resource, the capacitive sensing oscillator will be the clock source for timer0. refer to section 20.0 ?timer0 module? for additional information. cpsrm range cpsrng<1:0> mode nominal current (1) 0 low 00 off 0.0 ? a 01 low 0.25 ? a 10 medium 1.5 ? a 11 high 7.5 ? a 1 high 00 noise detection 0.0 ? a 01 low 9 ? a 10 medium 30 ? a 11 high 100 ? a note 1: see section 30.0 ?electrical specifications? for more information. note: the fixed time base can not be generated by the timer resource that the capacitive sensing oscillator is clocking.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 331 pic16(l)f1946/1947 26.2.4.2 timer1 to select timer1 as the timer resource for the cps module, set the tmr1cs<1:0> of the t1con register to ? 11 ?. when timer1 is chosen as the timer resource, the capacitive sensing oscillator will be the clock source for timer1. because the timer1 module has a gate control, developing a time base for the frequency measurement can be simplified by using the timer0 overflow flag. it is recommend that the timer0 overflow flag, in conjunction with the toggle mode of the timer1 gate, be used to develop the fixed time base required by the soft- ware portion of the cps module. refer to section 21.12 ?timer1 gate control register? for additional informa- tion. table 26-2: timer1 enable function 26.2.5 software control the software portion of the cps module is required to determine the change in frequency of the capacitive sensing oscillator. this is accomplished by the following: ? setting a fixed time base to acquire counts on timer0 or timer1. ? establishing the nominal frequency for the capacitive sensing oscillator. ? establishing the reduced frequency for the capac- itive sensing oscillator due to an additional capac- itive load. ? set the frequency threshold. 26.2.5.1 nominal frequency (no capacitive load) to determine the nominal frequency of the capacitive sensing oscillator: ? remove any extra capacitive load on the selected cpsx pin. ? at the start of the fixed time base, clear the timer resource. ? at the end of the fixed time base save the value in the timer resource. the value of the timer resource is the number of oscillations of the capacitive sensing oscillator for the given time base. the frequency of the capacitive sensing oscillator is equal to the number of counts on in the timer divided by the period of the fixed time base. 26.2.5.2 reduced frequency (additional capacitive load) the extra capacitive load will cause the frequency of the capacitive sensing oscillator to decrease. to determine the reduced frequency of the capacitive sensing oscillator: ? add a typical capacitive load on the selected cpsx pin. ? use the same fixed time base as the nominal frequency measurement. ? at the start of the fixed time base, clear the timer resource. ? at the end of the fixed time base save the value in the timer resource. the value of the timer resource is the number of oscil- lations of the capacitive sensing oscillator with an addi- tional capacitive load. the frequency of the capacitive sensing oscillator is equal to the number of counts on in the timer divided by the period of the fixed time base. this frequency should be less than the value obtained during the nominal frequency measurement. 26.2.5.3 frequency threshold the frequency threshold should be placed midway between the value of nominal frequency and the reduced frequency of the capacitive sensing oscillator. refer to application note an1103, ? software handling for capacitive sensing ? (ds01103) for more detailed information on the software required for cps module. tmr1on tmr1ge timer1 operation 00 off 01 off 10 on 11 count enabled by input note: for more information on general capacitive sensing refer to application notes: ? an1101, ? introduction to capacitive sensing ? (ds01101) ? an1102, ? layout and physical design guidelines for capacitive sensing ? (ds01102)
pic16(l)f1946/1947 ds41414c-page 332 preliminary ? 2010-2011 microchip technology inc. 26.3 operation during sleep the capacitive sensing oscillator will continue to run as long as the module is enabled, independent of the part being in sleep. in order for the software to determine if a frequency change has occurred, the part must be awake. however, the part does not have to be awake when the timer resource is acquiring counts. 26.4 capacitive sensing control registers note: timer0 does not operate when in sleep, and therefore cannot be used for capacitive sense measurements in sleep. register 26-1: cpscon0: capaciti ve sensing control register 0 r/w-0/0 r/w-0/0 u-0 u-0 r/w-0/0 r/w-0/0 r-0/0 r/w-0/0 cpson cpsrm ? ? cpsrng<1:0> cpsout t0xcs bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7 cpson: cps module enable bit 1 = cps module is enabled 0 = cps module is disabled bit 6 cpsrm: capacitive sensing reference mode bit 1 = cps module is in high range. dac and fvr provide oscillator voltage references. 0 = cps module is in the low range. internal oscillator voltage references are used. bit 5-4 unimplemented: read as ? 0 ? bit 3-2 cpsrng<1:0>: capacitive sensing current range if cpsrm = 0 (low range): 00 = oscillator is off 01 = oscillator is in low range. charge/discharge current is nominally 0.1 a 10 = oscillator is in medium range. charge/discharge current is nominally 1.2 a 11 = oscillator is in high range. charge/discharge current is nominally 18 a if cpsrm = 1 (high range): 00 = oscillator is on. noise detection mode. no charge/discharge current is supplied. 01 = oscillator is in low range. charge/discharge current is nominally 9 a 10 = oscillator is in medium range. charge/discharge current is nominally 30 a 11 = oscillator is in high range. charge/discharge current is nominally 100 a bit 1 cpsout: capacitive sensing oscillator status bit 1 = oscillator is sourcing current (current flowing out of the pin) 0 = oscillator is sinking current (current flowing into the pin) bit 0 t0xcs: timer0 external clock source select bit if tmr0cs = 1 : the t0xcs bit controls which clock external to the core/timer0 module supplies timer0: 1 = timer0 clock source is the capacitive sensing oscillator 0 = timer0 clock source is the t0cki pin if tmr0cs = 0 : timer0 clock source is controlled by the core/timer0 module and is f osc /4
? 2010-2011 microchip technology inc. preliminary ds41414c-page 333 pic16(l)f1946/1947 table 26-3: summary of registers as sociated with capacitive sensing register 26-2: cpscon1: capaciti ve sensing control register 1 u-0 u-0 u-0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 ? ? ? cpsch<4:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-5 unimplemented: read as ? 0 ? bit 4-0 cpsch<4:0>: capacitive sensing channel select bits if cpson = 0 : these bits are ignored. no channel is selected. if cpson = 1 : 00000 = channel 0, (cps0) 00001 = channel 1, (cps1) 00010 = channel 2, (cps2) 00011 = channel 3, (cps3) 00100 = channel 4, (cps4) 00101 = channel 5, (cps5) 00110 = channel 6, (cps6) 00111 = channel 7, (cps7) 01000 = channel 8, (cps8) 01001 = channel 9, (cps9) 01010 = channel 10, (cps10) 01011 = channel 11, (cps11) 01100 = channel 12, (cps12) 01101 = channel 13, (cps13) 01110 = channel 14, (cps14) 01111 = channel 15, (cps15) 10000 = channel 16, (cps16) 10001 = reserved. do not use. . . . 11111 = reserved. do not use. name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page ansela ? ? ansa5 ansa4 ansa3 ansa2 ansa1 ansa0 129 cpscon0 cpson cpsrm ? ? cpsrng<1:0> cpsout t0xcs 332 cpscon1 ? ? ? cpsch<4:0> 333 option_reg wpuen intedg tmr0cs tmr0se psa ps2 ps1 ps0 195 t1con tmr1cs<1:0> t1ckps<1:0> t1oscen t1sync ? tmr1on 205 trisa trisa7 trisa6 trisa5 trisa4 trisa3 trisa2 trisa1 trisa0 128 trisb trisb7 trisb6 trisb5 trisb4 trisb3 trisb2 trisb1 trisb0 131 trisd trisd<7:0> 137 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by the cps module.
pic16(l)f1946/1947 ds41414c-page 334 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 335 pic16(l)f1946/1947 27.0 liquid crystal display (lcd) driver module the liquid crystal display (lcd) driver module generates the timing control to drive a static or multiplexed lcd panel. in the pic16f/lf1946/47 device, the module drives the panels of up to four commons and up to 46 segments. the lcd module also provides control of the lcd pixel data. the lcd driver module supports: ? direct driving of lcd panel ? three lcd clock sources with selectable prescaler ? up to four common pins: - static (1 common) - 1/2 multiplex (2 commons) - 1/3 multiplex (3 commons) - 1/4 multiplex (4 commons) ? segment pins up to: - 64 (pic16(l)f1946/1947) ? static, 1/2 or 1/3 lcd bias 27.1 lcd registers the module contains the following registers: ? lcd control register (lcdcon) ? lcd phase register (lcdps) ? lcd reference ladder register (lcdrl) ? lcd contrast control register (lcdcst) ? lcd reference voltage control register (lcdref) ? up to 6 lcd segment enable registers (lcdsen) ? up to 24 lcd data registers (lcddatan) figure 27-1: lcd driver module block diagram data bus seg<23:0> to i/o pads (1) lcddatax registers note 1: these are not directly connected to the i/o pads, but may be tri-stated, depending on the configuration of the lcd module. com<3:0> clock source timing control select and prescaler lfintosc f osc /256 t1osc to i/o pads (1) lcdcon lcdps lcdsen mux
pic16(l)f1946/1947 ds41414c-page 336 preliminary ? 2010-2011 microchip technology inc. table 27-1: lcd segment and data registers the lcdcon register ( register 27-1 ) controls the operation of the lcd driver module. the lcdps regis- ter ( register 27-2 ) configures the lcd clock source prescaler and the type of waveform; type-a or type-b. the lcdsen registers ( register 27-5 ) configure the functions of the port pins. the following lcdsen registers are available: ? lcdse0 se<7:0> ? lcdse1 se<15:8> ? lcdse2 se<23:16> (1) ? lcdse3 se<31:24> ? lcdse4 se<39:32> ? lcdse5 se<45:40> once the module is initialized for the lcd panel, the individual bits of the lcddatan registers are cleared/set to represent a clear/dark pixel, respectively: ? lcddata0 seg<7:0>com0 ? lcddata1 seg<15:8>com0 ? lcddata2 seg<23:16>com0 ? lcddata3 seg<7:0>com1 ? lcddata4 seg<15:8>com1 ? lcddata5 seg<23:16>com1 ? lcddata6 seg<7:0>com2 ? lcddata7 seg<15:8>com2 ? lcddata8 seg<23:16>com2 ? lcddata9 seg<7:0>com3 ? lcddata10 seg<15:8>com3 ? lcddata11 seg<23:16>com3 ? lcddata12 seg<31:24>com0 ? lcddata13 seg<39:32>com0 ? lcddata14 seg<45:40>com0 ? lcddata15 seg<31:24>com1 ? lcddata16 seg<39:32>com1 ? lcddata17 seg<45:40>com1 ? lcddata18 seg<31:24>com2 ? lcddata19 seg<39:32>com2 ? lcddata20 seg<45:40>com2 ? lcddata21 seg<31:24>com3 ? lcddata22 seg<39:32>com3 ? lcddata23 seg<45:40>com3 as an example, lcddatan is detailed in register 27-6 . once the module is configured, the lcden bit of the lcdcon register is used to enable or disable the lcd module. the lcd panel can also operate during sleep by clearing the slpen bit of the lcdcon register. device # of lcd registers segment enable data pic16(l)f1946/1947 6 24
? 2010-2011 microchip technology inc. preliminary ds41414c-page 337 pic16(l)f1946/1947 27.2 liquid crystal display (lcd) control registers register 27-1: lcdcon: liquid crystal display (lcd) control register r/w-0/0 r/w-0/0 r/c-0/0 u-0 r/w-0/0 r/w-0/0 r/w-1/1 r/w-1/1 lcden slpen werr ? cs<1:0> lmux<1:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared c = only clearable bit bit 7 lcden: lcd driver enable bit 1 = lcd driver module is enabled 0 = lcd driver module is disabled bit 6 slpen: lcd driver enable in sleep mode bit 1 = lcd driver module is disabled in sleep mode 0 = lcd driver module is enabled in sleep mode bit 5 werr: lcd write failed error bit 1 = lcddatan register written while the wa bit of the lcdps register = 0 (must be cleared in software) 0 = no lcd write error bit 4 unimplemented: read as ? 0 ? bit 3-2 cs<1:0>: clock source select bits 00 = f osc /256 01 = t1osc (timer1) 1x = lfintosc (31 khz) bit 1-0 lmux<1:0>: commons select bits lmux<1:0> multiplex maximum number of pixels bias pic16f1946/47/ pic16lf1946/47 00 static (com0) 46 static 01 1/2 (com<1:0>) 92 1/2 or 1/3 10 1/3 (com<2:0>) 138 1/2 or 1/3 11 1/4 (com<3:0>) 184 1/3
pic16(l)f1946/1947 ds41414c-page 338 preliminary ? 2010-2011 microchip technology inc. register 27-2: lcdps: lcd phase register r/w-0/0 r/w-0/0 r-0/0 r-0/0 r/w-0/0 r/w-0/0 r/w-1/1 r/w-1/1 wft biasmd lcda wa lp<3:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared c = only clearable bit bit 7 wft: waveform type bit 1 = type-b phase changes on each frame boundary 0 = type-a phase changes within each common type bit 6 biasmd: bias mode select bit when lmux<1:0> = 00 : 0 = static bias mode (do not set this bit to ? 1 ?) when lmux<1:0> = 01 : 1 = 1/2 bias mode 0 = 1/3 bias mode when lmux<1:0> = 10 : 1 = 1/2 bias mode 0 = 1/3 bias mode when lmux<1:0> = 11 : 0 = 1/3 bias mode (do not set this bit to ? 1 ?) bit 5 lcda: lcd active status bit 1 = lcd driver module is active 0 = lcd driver module is inactive bit 4 wa: lcd write allow status bit 1 = writing to the lcddatan registers is allowed 0 = writing to the lcddatan registers is not allowed bit 3-0 lp<3:0>: lcd prescaler selection bits 1111 = 1:16 1110 = 1:15 1101 = 1:14 1100 = 1:13 1011 = 1:12 1010 = 1:11 1001 = 1:10 1000 = 1:9 0111 = 1:8 0110 = 1:7 0101 = 1:6 0100 = 1:5 0011 = 1:4 0010 = 1:3 0001 = 1:2 0000 = 1:1
? 2010-2011 microchip technology inc. preliminary ds41414c-page 339 pic16(l)f1946/1947 register 27-3: lcdref: lcd refe rence voltage control register r/w-0/0 r/w-0/0 r/w-0/0 u-0 r/w-0/0 r/w-0/0 r/w-0/0 u-0 lcdire lcdirs lcdiri ? vlcd3pe vlcd2pe vlcd1pe ? bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared c = only clearable bit bit 7 lcdire: lcd internal reference enable bit 1 = internal lcd reference is enabled and connected to the internal contrast control circuit 0 = internal lcd reference is disabled bit 6 lcdirs: lcd internal reference source bit if lcdire = 1: 0 = internal lcd contrast control is powered by v dd 1 = internal lcd contrast control is powered by a 3.072v output of the fvr. if lcdire = 0 : internal lcd contrast control is unconnected. lcd bandgap buffer is disabled. bit 5 lcdiri: lcd internal reference ladder idle enable bit allows the internal fvr buffer to shut down when the lcd reference ladder is in power mode ?b? 1 = when the lcd reference ladder is in power mode ?b?, the lcd internal fvr buffer is disabled. 0 = the lcd internal fvr buffer ignores the lcd reference ladder power mode. bit 4 unimplemented: read as ? 0 ? bit 3 vlcd3pe: vlcd3 pin enable bit 1 = the vlcd3 pin is connected to the internal bias voltage lcdbias3 (1) 0 = the vlcd3 pin is not connected bit 2 vlcd2pe: vlcd2 pin enable bit 1 = the vlcd2 pin is connected to the internal bias voltage lcdbias2 (1) 0 = the vlcd2 pin is not connected bit 1 vlcd1pe: vlcd1 pin enable bit 1 = the vlcd1 pin is connected to the internal bias voltage lcdbias1 (1) 0 = the vlcd1 pin is not connected bit 0 unimplemented: read as ? 0 ? note 1: normal pin controls of trisx and anselx are unaffected.
pic16(l)f1946/1947 ds41414c-page 340 preliminary ? 2010-2011 microchip technology inc. register 27-4: lcdcst: lcd contrast control register u-0 u-0 u-0 u-0 u-0 r/w-0/0 r/w-0/0 r/w-0/0 ? ? ? ? ? lcdcst<2:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared c = only clearable bit bit 7-3 unimplemented: read as ? 0 ? bit 2-0 lcdcst<2:0>: lcd contrast control bits selects the resistance of the lcd contrast control resistor ladder bit value = resistor ladder 000 = minimum resistance (maximum contrast). resistor ladder is shorted. 001 = resistor ladder is at 1/7th of maximum resistance 010 = resistor ladder is at 2/7th of maximum resistance 011 = resistor ladder is at 3/7th of maximum resistance 100 = resistor ladder is at 4/7th of maximum resistance 101 = resistor ladder is at 5/7th of maximum resistance 110 = resistor ladder is at 6/7th of maximum resistance 111 = resistor ladder is at maximum resistance (minimum contrast).
? 2010-2011 microchip technology inc. preliminary ds41414c-page 341 pic16(l)f1946/1947 register 27-5: lcdsen: lcd segment enable registers r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 sen sen sen sen sen sen sen sen bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 sen: segment enable bits 1 = segment function of the pin is enabled 0 = i/o function of the pin is enabled register 27-6: lcddatan: lcd data registers r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u r/w-x/u segx-comy segx-comy segx-comy segx-comy segx-comy segx-comy segx-comy segx-comy bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-0 segx-comy: pixel on bits 1 = pixel on (dark) 0 = pixel off (clear)
pic16(l)f1946/1947 ds41414c-page 342 preliminary ? 2010-2011 microchip technology inc. 27.3 lcd clock source selection the lcd module has 3 possible clock sources: ?f osc /256 ?t1osc ?lfintosc the first clock source is the system clock divided by 256 (f osc /256). this divider ratio is chosen to provide about 1 khz output when the system clock is 8 mhz. the divider is not programmable. instead, the lcd prescaler bits lp<3:0> of the lcdps register are used to set the lcd frame clock rate. the second clock source is the t1osc. this also gives about 1 khz when a 32.768 khz crystal is used with the timer1 oscillator. to use the timer1 oscillator as a clock source, the t1oscen bit of the t1con register should be set. the third clock source is the 31 khz lfintosc, which provides approximately 1 khz output. the second and third clock sources may be used to continue running the lcd while the processor is in sleep. using bits cs<1:0> of the lcdcon register can select any of these clock sources. 27.3.1 lcd prescaler a 4-bit counter is available as a prescaler for the lcd clock. the prescaler is not directly readable or writable; its value is set by the lp<3:0> bits of the lcdps register, which determine the prescaler assignment and prescale ratio. the prescale values are selectable from 1:1 through 1:16. figure 27-2: lcd cl ock generation cs<1:0> t1osc 32 khz crystal osc. lfintosc nominal = 31 khz static 1/2 1/3, 1/4 4 lmux<1:0> 4-bit prog 1, 2, 3, 4 ring counter com0 com1 com2 com3 256 f osc 2 32 lp<3:0> prescaler to ladder power control segment clock counter
? 2010-2011 microchip technology inc. preliminary ds41414c-page 343 pic16(l)f1946/1947 27.4 lcd bias voltage generation the lcd module can be configured for one of three bias types: ? static bias (2 voltage levels: v ss and v lcd ) ? 1/2 bias (3 voltage levels: v ss , 1/2 v lcd and v lcd ) ? 1/3 bias (4 voltage levels: v ss , 1/3 v lcd , 2/3 v lcd and v lcd ) table 27-2: lcd bias voltages so that the user is not forced to place external compo- nents and use up to three pins for bias voltage generation, internal contrast control and an internal reference ladder are provided internally to the pic16f/lf1946/47. both of these features may be used in conjunction with the exter- nal vlcd<3:1> pins, to provide maximum flexibility. refer to figure 27-3 . figure 27-3: lcd bias volt age generation block diagram static bias 1/2 bias 1/3 bias lcd bias 0 v ss v ss v ss lcd bias 1 ?1/2 v dd 1/3 v dd lcd bias 2 ?1/2 v dd 2/3 v dd lcd bias 3 v lcd 3v lcd 3v lcd 3 v dd lcdire x 3 3.072v 1.024v from fvr vlcd3 lcdirs lcdire lcdirs lcdcst<2:0> vlcd3pe vlcd2 vlcd2pe vlcd1 vlcd1pe biasmd lcdbias3 lcdbias2 lcdbias1 lcdbias0 lcda lcda lcda a b power mode switching (lrlap or lrlbp) 2 2 2
pic16(l)f1946/1947 ds41414c-page 344 preliminary ? 2010-2011 microchip technology inc. 27.5 lcd bias internal reference ladder the internal reference ladder can be used to divide the lcd bias voltage two or three equally spaced voltages that will be supplied to the lcd segment pins. to create this, the reference ladder consists of three matched resistors. refer to figure 27-3 . 27.5.1 bias mode interaction when in 1/2 bias mode (biasmd = 1 ), then the middle resistor of the ladder is shorted out so that only two voltages are generated. the current consumption of the ladder is higher in this mode, with the one resistor removed. table 27-3: lcd internal ladder power modes (1/3 bias) 27.5.2 power modes the internal reference ladder may be operated in one of three power modes. this allows the user to trade off lcd contrast for power in the specific application. the larger the lcd glass, the more capacitance is present on a physical lcd segment, requiring more current to maintain the same contrast level. three different power modes are available, lp, mp and hp. the internal reference ladder can also be turned off for applications that wish to provide an external ladder or to minimize power consumption. disabling the internal reference ladder results in all of the ladders being disconnected, allowing external voltages to be supplied. whenever the lcd module is inactive (lcda = 0 ), the internal reference ladder will be turned off. power mode nominal resistance of entire ladder nominal i dd low 3 mohm 1 a medium 300 kohm 10 a high 30 kohm 100 a
? 2010-2011 microchip technology inc. preliminary ds41414c-page 345 pic16(l)f1946/1947 27.5.3 automatic power mode switching as an lcd segment is electrically only a capacitor, cur- rent is drawn only during the interval where the voltage is switching. to minimize total device current, the lcd internal reference ladder can be operated in a different power mode for the transition portion of the duration. this is controlled by the lcdrl register ( register 27-7 ). the lcdrl register allows switching between two power modes, designated ?a? and ?b?. ?a? power mode is active for a programmable time, beginning at the time when the lcd segments transition. ?b? power mode is the remaining time before the segments or commons change again. the lrlat<2:0> bits select how long, if any, that the ?a? power mode is active. refer to figure 27-4 . to implement this, the 5-bit prescaler used to divide the 32 khz clock down to the lcd controller?s 1 khz base rate is used to select the power mode. figure 27-4: lcd internal reference l adder power mode switching diagram ? type a single segment time ?h00 ?h01 ?h02 ?h03 ?h04 ?h05 ?h06 ?h07 ?h0e ?h0f ?h00 ?h01 ?h3 power mode a power mode b mode a lrlat<2:0> 32 khz clock ladder power segment clock lrlat<2:0> segment data power mode com0 seg0 com0-seg0 control v 0 v 1 v 0 v 1 v 0 v 1 -v 1
pic16(l)f1946/1947 ds41414c-page 346 preliminary ? 2010-2011 microchip technology inc. figure 27-5: lcd internal reference ladder power mode switching diagram ? type a waveform (1/2 mux, 1/2 bias drive) single segment time ?h00 ?h01 ?h02 ?h03 ?h04 ?h05 ?h06 ?h07 ?h0f power mode a power mode b lrlat<2:0> = 011 32 khz clock ladder power segment clock segment data power mode com0-seg0 control v 1 v 2 v 0 -v 2 -v 1 single segment time ?h00 ?h01 ?h02 ?h03 ?h04 ?h05 ?h06 ?h07 ?h0f power mode a power mode b ?h0e ?h0e lrlat<2:0> = 011
? 2010-2011 microchip technology inc. preliminary ds41414c-page 347 pic16(l)f1946/1947 figure 27-6: lcd internal reference ladder power mode switching diagram ? type b waveform (1/2 mux, 1/2 bias drive) single segment time ?h00 ?h01 ?h02 ?h03 ?h0f power mode a power mode b 32 khz clock ladder power segment clock segment data power mode com0-seg0 control v 1 v 2 v 0 -v 2 -v 1 ?h0e single segment time ?h10 ?h11 ?h12 ?h13 ?h1f power mode a power mode b ?h1e single segment time ?h00 ?h01 ?h02 ?h03 ?h0f power mode a power mode b ?h0e single segment time ?h10 ?h11 ?h12 ?h13 ?h1f power mode a power mode b ?h1e lrlat<2:0> = 011 lrlat<2:0> = 011 lrlat<2:0> = 011 lrlat<2:0> = 011
pic16(l)f1946/1947 ds41414c-page 348 preliminary ? 2010-2011 microchip technology inc. register 27-7: lcdrl: lcd refere nce ladder control registers r/w-0/0 r/w-0/0 r/w-0/0 r/w-0/0 u-0 r/w-0/0 r/w-0/0 r/w-0/0 lrlap<1:0> lrlbp<1:0> ? lrlat<2:0> bit 7 bit 0 legend: r = readable bit w = writable bit u = unimplemented bit, read as ?0? u = bit is unchanged x = bit is unknown -n/n = value at por and bor/value at all other resets ?1? = bit is set ?0? = bit is cleared bit 7-6 lrlap<1:0>: lcd reference ladder a time power control bits during time interval a (refer to figure 27-4 ): 00 = internal lcd reference ladder is powered down and unconnected 01 = internal lcd reference ladder is powered in low-power mode 10 = internal lcd reference ladder is powered in medium-power mode 11 = internal lcd reference ladder is powered in high-power mode bit 5-4 lrlbp<1:0>: lcd reference ladder b time power control bits during time interval b (refer to figure 27-4 ): 00 = internal lcd reference ladder is powered down and unconnected 01 = internal lcd reference ladder is powered in low-power mode 10 = internal lcd reference ladder is powered in medium-power mode 11 = internal lcd reference ladder is powered in high-power mode bit 3 unimplemented: read as ? 0 ? bit 2-0 lrlat<2:0>: lcd reference ladder a time interval control bits sets the number of 32 khz clocks that the a time interval power mode is active for type a waveforms (wft = 0 ): 000 = internal lcd reference ladder is always in ?b? power mode 001 = internal lcd reference ladder is in ?a? power mode for 1 clock and ?b? power mode for 15 clocks 010 = internal lcd reference ladder is in ?a? power mode for 2 clocks and ?b? power mode for 14 clocks 011 = internal lcd reference ladder is in ?a? power mode for 3 clocks and ?b? power mode for 13 clocks 100 = internal lcd reference ladder is in ?a? power mode for 4 clocks and ?b? power mode for 12 clocks 101 = internal lcd reference ladder is in ?a? power mode for 5 clocks and ?b? power mode for 11 clocks 110 = internal lcd reference ladder is in ?a? power mode for 6 clocks and ?b? power mode for 10 clocks 111 = internal lcd reference ladder is in ?a? power mode for 7 clocks and ?b? power mode for 9 clocks for type b waveforms (wft = 1 ): 000 = internal lcd reference ladder is always in ?b? power mode. 001 = internal lcd reference ladder is in ?a? power mode for 1 clock and ?b? power mode for 31 clocks 010 = internal lcd reference ladder is in ?a? power mode for 2 clocks and ?b? power mode for 30 clocks 011 = internal lcd reference ladder is in ?a? power mode for 3 clocks and ?b? power mode for 29 clocks 100 = internal lcd reference ladder is in ?a? power mode for 4 clocks and ?b? power mode for 28 clocks 101 = internal lcd reference ladder is in ?a? power mode for 5 clocks and ?b? power mode for 27 clocks 110 = internal lcd reference ladder is in ?a? power mode for 6 clocks and ?b? power mode for 26 clocks 111 = internal lcd reference ladder is in ?a? power mode for 7 clocks and ?b? power mode for 25 clocks
? 2010-2011 microchip technology inc. preliminary ds41414c-page 349 pic16(l)f1946/1947 27.5.4 contrast control the lcd contrast control circuit consists of a seven-tap resistor ladder, controlled by the lcdcst bits. refer to figure 27-7 . the contrast control circuit is used to decrease the output voltage of the signal source by a total of approximately 10%, when lcdcst = 111 . whenever the lcd module is inactive (lcda = 0 ), the contrast control ladder will be turned off (open). figure 27-7: internal reference and contrast contro l block diagram 27.5.5 internal reference under firmware control, an internal reference for the lcd bias voltages can be enabled. when enabled, the source of this voltage can be either v ddio or a voltage 3 times the main fixed voltage reference (3.072v). when no internal reference is selected, the lcd con- trast control circuit is disabled and lcd bias must be provided externally. whenever the lcd module is inactive (lcda = 0 ), the internal reference will be turned off. when the internal reference is enabled and the fixed voltage reference is selected, the lcdiri bit can be used to minimize power consumption by tieing into the lcd reference ladder automatic power mode switching. when lcdiri = 1 and the lcd reference ladder is in power mode ?b?, the lcd internal fvr buffer is disables. . 27.5.6 vlcd<3:1> pins the vlcd<3:1> pins provide the ability for an external lcd bias network to be used instead of the internal lad- der. use of the vlcd<3:1> pins does not prevent use of the internal ladder. each vlcd pin has an indepen- dent control in the lcdref register ( register 27-3 ), allowing access to any or all of the lcd bias signals. this architecture allows for maximum flexibility in different applications for example, the vlcd<3:1> pins may be used to add capacitors to the internal reference ladder, increasing the drive capacity. for applications where the internal contrast control is insufficient, the firmware can choose to only enable the vlcd3 pin, allowing an external contrast control circuit to use the internal reference divider. lcdcst<2:0> analog rr rr 7 stages mux to top of reference ladder 7 0 3 3.072v v ddio from fvr buffer internal reference contrast control note: the lcd module automatically turns on the fixed voltage reference when needed.
pic16(l)f1946/1947 ds41414c-page 350 preliminary ? 2010-2011 microchip technology inc. 27.6 lcd multiplex types the lcd driver module can be configured into one of four multiplex types: ? static (only com0 is used) ? 1/2 multiplex (com<1:0> are used) ? 1/3 multiplex (com<2:0> are used) ? 1/4 multiplex (com<3:0> are used) the lmux<1:0> bit setting of the lcdcon register decides which of the lcd common pins are used (see table 27-4 for details). if the pin is a digital i/o, the corresponding tris bit controls the data direction. if the pin is a com drive, then the tris setting of that pin is overridden. table 27-4: common pin usage 27.7 segment enables the lcdsen registers are used to select the pin function for each segment pin. the selection allows each pin to operate as either an lcd segment driver or as one of the pin?s alternate functions. to configure the pin as a segment pin, the corresponding bits in the lcdsen registers must be set to ? 1 ?. if the pin is a digital i/o, the corresponding tris bit controls the data direction. any bit set in the lcdsen registers overrides any bit settings in the corresponding tris register. 27.8 pixel control the lcddatax registers contain bits which define the state of each pixel. each bit defines one unique pixel. register 27-6 shows the correlation of each bit in the lcddatax registers to the respective common and segment signals. any lcd pixel location not being used for display can be used as general purpose ram. 27.9 lcd frame frequency the rate at which the com and seg outputs change is called the lcd frame frequency. table 27-5: frame frequency formulas table 27-6: approximate frame frequency (in hz) using f osc @ 8 mhz, timer1 @ 32.768 khz or lfintosc multiplex lmux <1:0> com3 com2 com1 com0 static 00 unused unused unused active 1/2 01 unused unused active active 1/3 10 unused active active active 1/4 11 active active active active note: on a power-on reset, these pins are configured as normal i/o, not lcd pins. multiplex frame frequency (2) = static clock source/(4 x (lcd prescaler) x 32 x 1)) 1/2 clock source/(2 x (lcd prescaler) x 32 x 2)) 1/3 clock source/(1 x (lcd prescaler) x 32 x 3)) 1/4 clock source/(1 x (lcd prescaler) x 32 x 4)) note 1: clock source is f osc /256, t1osc or lfintosc. 2: see figure 27-2 . lp<3:0> static 1/2 1/3 1/4 2 122 122 162 122 3 81 81 108 81 461618161 549496549 641415441 735354735
? 2010-2011 microchip technology inc. preliminary ds41414c-page 351 pic16(l)f1946/1947 table 27-7: lcd segment mapping worksheet lcd function com0 com1 com2 com3 lcddatax address lcd segment lcddatax address lcd segment lcddatax address lcd segment lcddatax address lcd segment seg0 lcddata0, 0 lcddata3, 0 lcddata6, 0 lcddata9, 0 seg1 lcddata0, 1 lcddata3, 1 lcddata6, 1 lcddata9, 1 seg2 lcddata0, 2 lcddata3, 2 lcddata6, 2 lcddata9, 2 seg3 lcddata0, 3 lcddata3, 3 lcddata6, 3 lcddata9, 3 seg4 lcddata0, 4 lcddata3, 4 lcddata6, 4 lcddata9, 4 seg5 lcddata0, 5 lcddata3, 5 lcddata6, 5 lcddata9, 5 seg6 lcddata0, 6 lcddata3, 6 lcddata6, 6 lcddata9, 6 seg7 lcddata0, 7 lcddata3, 7 lcddata6, 7 lcddata9, 7 seg8 lcddata1, 0 lcddata4, 0 lcddata7, 0 lcddata10, 0 seg9 lcddata1, 1 lcddata4, 1 lcddata7, 1 lcddata10, 1 seg10 lcddata1, 2 lcddata4, 2 lcddata7, 2 lcddata10, 2 seg11 lcddata1, 3 lcddata4, 3 lcddata7, 3 lcddata10, 3 seg12 lcddata1, 4 lcddata4, 4 lcddata7, 4 lcddata10, 4 seg13 lcddata1, 5 lcddata4, 5 lcddata7, 5 lcddata10, 5 seg14 lcddata1, 6 lcddata4, 6 lcddata7, 6 lcddata10, 6 seg15 lcddata1, 7 lcddata4, 7 lcddata7, 7 lcddata10, 7 seg16 lcddata2, 0 lcddata5, 0 lcddata8, 0 lcddata11, 0 seg17 lcddata2, 1 lcddata5, 1 lcddata8, 1 lcddata11, 1 seg18 lcddata2, 2 lcddata5, 2 lcddata8, 2 lcddata11, 2 seg19 lcddata2, 3 lcddata5, 3 lcddata8, 3 lcddata11, 3 seg20 lcddata2, 4 lcddata5, 4 lcddata8, 4 lcddata11, 4 seg21 lcddata2, 5 lcddata5, 5 lcddata8, 5 lcddata11, 5 seg22 lcddata2, 6 lcddata5, 6 lcddata8, 6 lcddata11, 6 seg23 lcddata2, 7 lcddata5, 7 lcddata8, 7 lcddata11, 7 seg24 lcddata12, 0 lcddata15, 0 lcddata18, 0 lcddata21, 0 seg25 lcddata12, 1 lcddata15, 1 lcddata18, 1 lcddata21, 1 seg26 lcddata12, 2 lcddata15, 2 lcddata18, 2 lcddata21, 2 seg27 lcddata12, 3 lcddata15, 3 lcddata18, 3 lcddata21, 3 seg28 lcddata12, 4 lcddata15, 4 lcddata18, 4 lcddata21, 4 seg29 lcddata12, 5 lcddata15, 5 lcddata18, 5 lcddata21, 5 seg30 lcddata12, 6 lcddata15, 6 lcddata18, 6 lcddata21, 6 seg31 lcddata12, 7 lcddata15, 7 lcddata18, 7 lcddata21, 7 seg32 lcddata13, 0 lcddata16, 0 lcddata19, 0 lcddata22, 0 seg33 lcddata13, 1 lcddata16, 1 lcddata19, 1 lcddata22, 1 seg34 lcddata13, 2 lcddata16, 2 lcddata19, 2 lcddata22, 2 seg35 lcddata13, 3 lcddata16, 3 lcddata19, 3 lcddata22, 3 seg36 lcddata13, 4 lcddata16, 4 lcddata19, 4 lcddata22, 4 seg37 lcddata13, 5 lcddata16, 5 lcddata19, 5 lcddata22, 5 seg38 lcddata13, 6 lcddata16, 6 lcddata19, 6 lcddata22, 6 seg39 lcddata13, 7 lcddata16, 7 lcddata19, 7 lcddata22, 7 seg40 lcddata14, 0 lcddata17, 0 lcddata20, 0 lcddata23, 0 seg41 lcddata14, 1 lcddata17, 1 lcddata20, 1 lcddata23, 1 seg42 lcddata14, 2 lcddata17, 2 lcddata20, 2 lcddata23, 2 seg43 lcddata14, 3 lcddata17, 3 lcddata20, 3 lcddata23, 3 seg44 lcddata14, 4 lcddata17, 4 lcddata20, 4 lcddata23, 4 seg45 lcddata14, 5 lcddata17, 5 lcddata20, 5 lcddata23, 5
pic16(l)f1946/1947 ds41414c-page 352 preliminary ? 2010-2011 microchip technology inc. 27.10 lcd waveform generation lcd waveforms are generated so that the net ac voltage across the dark pixel should be maximized and the net ac voltage across the clear pixel should be minimized. the net dc voltage across any pixel should be zero. the com signal represents the time slice for each common, while the seg contains the pixel data. the pixel signal (com-seg) will have no dc component and it can take only one of the two rms values. the higher rms value will create a dark pixel and a lower rms value will create a clear pixel. as the number of commons increases, the delta between the two rms values decreases. the delta represents the maximum contrast that the display can have. the lcds can be driven by two types of waveform: type-a and type-b. in type-a waveform, the phase changes within each common type, whereas in type-b waveform, the phase changes on each frame boundary. thus, type-a waveform maintains 0 v dc over a single frame, whereas type-b waveform takes two frames. figure 27-8 through figure 27-18 provide waveforms for static, half-multiplex, 1/3-multiplex and 1/4-multiplex drives for type-a and type-b waveforms. figure 27-8: type-a/type-b waveforms in static drive note 1: if sleep has to be executed with lcd sleep disabled (lcdcon is ? 1 ?), then care must be taken to execute sleep only when v dc on all the pixels is ? 0 ?. 2: when the lcd clock source is f osc /256, if sleep is executed, irrespective of the lcdcon setting, the lcd immediately goes into sleep. thus, take care to see that v dc on all pixels is ? 0 ? when sleep is executed. v 1 v 0 com0 pin seg0 pin com0-seg0 com0-seg1 seg1 pin v 1 v 0 v 1 v 0 v 0 v 1 -v 1 v 0 1 frame com0 seg0 seg1 seg2 seg3 seg4 seg5 seg6 seg7 segment voltage (active) segment voltage (inactive)
? 2010-2011 microchip technology inc. preliminary ds41414c-page 353 pic16(l)f1946/1947 figure 27-9: type-a waveforms in 1/2 mux, 1/2 bias drive v 2 v 1 v 0 v 2 v 1 v 0 v 2 v 1 v 0 v 2 v 1 v 0 v 2 v 1 v 0 -v 2 -v 1 v 2 v 1 v 0 -v 2 -v 1 com0 pin com1 pin seg0 pin seg1 pin com0-seg0 com0-seg1 1 frame com1 com0 seg0 seg1 seg2 seg3 1 segment time note: 1 frame = 2 single segment times. segment voltage segment voltage (active) (inactive)
pic16(l)f1946/1947 ds41414c-page 354 preliminary ? 2010-2011 microchip technology inc. figure 27-10: type-b waveforms in 1/2 mux, 1/2 bias drive v 2 v 1 v 0 v 2 v 1 v 0 v 2 v 1 v 0 v 2 v 1 v 0 v 2 v 1 v 0 -v 2 -v 1 v 2 v 1 v 0 -v 2 -v 1 com0 pin com1 pin seg0 pin seg1 pin com0-seg0 com0-seg1 com1 com0 seg2 seg3 2 frames note: 1 frame = 2 single segment times. 1 segment time segment voltage (active) segment voltage (inactive) seg0 seg1
? 2010-2011 microchip technology inc. preliminary ds41414c-page 355 pic16(l)f1946/1947 figure 27-11: type-a waveforms in 1/2 mux, 1/3 bias drive v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 -v 3 -v 2 -v 1 v 3 v 2 v 1 v 0 -v 3 -v 2 -v 1 com0 pin com1 pin seg0 pin seg1 pin com0-seg0 com0-seg1 1 frame com1 com0 seg2 seg3 segment voltage (active) segment voltage (inactive) seg0 seg1 1 segment time note: 1 frame = 2 single segment times.
pic16(l)f1946/1947 ds41414c-page 356 preliminary ? 2010-2011 microchip technology inc. figure 27-12: type-b waveforms in 1/2 mux, 1/3 bias drive v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 -v 3 -v 2 -v 1 v 3 v 2 v 1 v 0 -v 3 -v 2 -v 1 com0 pin com1 pin seg0 pin seg1 pin com0-seg0 com0-seg1 com1 com0 seg2 seg3 segment voltage (active) segment voltage (inactive) seg0 seg1 2 frames note: 1 frame = 2 single segment times. 1 segment time
? 2010-2011 microchip technology inc. preliminary ds41414c-page 357 pic16(l)f1946/1947 figure 27-13: type-a waveforms in 1/3 mux, 1/2 bias drive v 2 v 1 v 0 v 2 v 1 v 0 v 2 v 1 v 0 v 2 v 1 v 0 v 2 v 1 v 0 v 2 v 1 v 0 -v 2 -v 1 v 2 v 1 v 0 -v 2 -v 1 com0 pin com1 pin com2 pin seg0 and seg1 pin com0-seg0 com0-seg1 com2 com1 com0 seg0 seg1 seg2 seg2 pins segment voltage (inactive) segment voltage (active) 1 frame 1 segment time note: 1 frame = 2 single segment times.
pic16(l)f1946/1947 ds41414c-page 358 preliminary ? 2010-2011 microchip technology inc. figure 27-14: type-b waveforms in 1/3 mux, 1/2 bias drive v 2 v 1 v 0 v 2 v 1 v 0 v 2 v 1 v 0 v 2 v 1 v 0 v 2 v 1 v 0 v 2 v 1 v 0 -v 2 -v 1 v 2 v 1 v 0 -v 2 -v 1 com0 pin com1 pin com2 pin seg0 pin seg1 pin com0-seg0 com0-seg1 com2 com1 com0 seg0 seg1 seg2 segment voltage (inactive) segment voltage (active) 2 frames note: 1 frame = 2 single segment times. 1 segment time
? 2010-2011 microchip technology inc. preliminary ds41414c-page 359 pic16(l)f1946/1947 figure 27-15: type-a waveforms in 1/3 mux, 1/3 bias drive v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 -v 3 -v 2 -v 1 v 3 v 2 v 1 v 0 -v 3 -v 2 -v 1 com0 pin com1 pin com2 pin seg0 and seg1 pin com0-seg0 com0-seg1 com2 com1 com0 seg0 seg1 seg2 seg2 pins segment voltage (inactive) segment voltage (active) 1 frame 1 segment time note: 1 frame = 2 single segment times.
pic16(l)f1946/1947 ds41414c-page 360 preliminary ? 2010-2011 microchip technology inc. figure 27-16: type-b waveforms in 1/3 mux, 1/3 bias drive v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 -v 3 -v 2 -v 1 v 3 v 2 v 1 v 0 -v 3 -v 2 -v 1 com0 pin com1 pin com2 pin seg0 pin seg1 pin com0-seg0 com0-seg1 com2 com1 com0 seg0 seg1 seg2 segment voltage (inactive) segment voltage (active) 2 frames note: 1 frame = 2 single segment times. 1 segment time
? 2010-2011 microchip technology inc. preliminary ds41414c-page 361 pic16(l)f1946/1947 figure 27-17: type-a waveforms in 1/4 mux, 1/3 bias drive v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 -v 3 -v 2 -v 1 v 3 v 2 v 1 v 0 -v 3 -v 2 -v 1 com0 pin com1 pin com2 pin com3 pin seg0 pin seg1 pin com0-seg0 com0-seg1 com3 com2 com1 com0 seg0 seg1 segment voltage (active) segment voltage (inactive) 1 frame 1 segment time note: 1 frame = 2 single segment times.
pic16(l)f1946/1947 ds41414c-page 362 preliminary ? 2010-2011 microchip technology inc. figure 27-18: type-b waveforms in 1/4 mux, 1/3 bias drive v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 -v 3 -v 2 -v 1 v 3 v 2 v 1 v 0 -v 3 -v 2 -v 1 com0 pin com1 pin com2 pin com3 pin seg0 pin seg1 pin com0-seg0 com0-seg1 com2 com1 com0 seg0 seg1 com3 segment voltage (active) segment voltage (inactive) 2 frames note: 1 frame = 2 single segment times. 1 segment time
? 2010-2011 microchip technology inc. preliminary ds41414c-page 363 pic16(l)f1946/1947 27.11 lcd interrupts the lcd module provides an interrupt in two cases. an interrupt when the lcd controller goes from active to inactive controller. an interrupt also provides unframe boundaries for type b waveform. the lcd timing gen- eration provides an interrupt that defines the lcd frame timing. 27.11.1 lcd interrupt on module shutdown an lcd interrupt is generated when the module completes shutting down (lcda goes from ? 1 ? to ? 0 ?). 27.11.2 lcd frame interrupts a new frame is defined to begin at the leading edge of the com0 common signal. the interrupt will be set immediately after the lcd controller completes access- ing all pixel data required for a frame. this will occur at a fixed interval before the frame boundary (t fint ), as shown in figure 27-19 . the lcd controller will begin to access data for the next frame within the interval from the interrupt to when the controller begins to access data after the interrupt (t fwr ). new data must be writ- ten within t fwr , as this is when the lcd controller will begin to access the data for the next frame. when the lcd driver is running with type-b waveforms and the lmux<1:0> bits are not equal to ? 00 ? (static drive), there are some additional issues that must be addressed. since the dc voltage on the pixel takes two frames to maintain zero volts, the pixel data must not change between subsequent frames. if the pixel data were allowed to change, the waveform for the odd frames would not necessarily be the complement of the waveform generated in the even frames and a dc component would be introduced into the panel. therefore, when using type-b waveforms, the user must synchronize the lcd pixel updates to occur within a subframe after the frame interrupt. to correctly sequence writing while in type-b, the interrupt will only occur on complete phase intervals. if the user attempts to write when the write is disabled, the werr bit of the lcdcon register is set and the write does not occur. note: the lcd frame interrupt is not generated when the type-a waveform is selected and when the type-b with no multiplex (static) is selected.
pic16(l)f1946/1947 ds41414c-page 364 preliminary ? 2010-2011 microchip technology inc. figure 27-19: waveforms and interrupt ti ming in quarter- duty cycle drive (example ? type-b, non-static) frame boundary frame boundary lcd interrupt occurs controller accesses next frame data t fint t fwr t fwr =t frame /2*(lmux<1:0> + 1) + t cy /2 t fint =(t fwr /2 ? (2 t cy + 40 ns)) ? minimum = 1.5(t frame /4) ? (2 t cy + 40 ns) (t fwr /2 ? (1 t cy + 40 ns)) ? maximum = 1.5(t frame /4) ? (1 t cy + 40 ns) frame boundary v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 com0 com1 com2 com3 2 frames
? 2010-2011 microchip technology inc. preliminary ds41414c-page 365 pic16(l)f1946/1947 27.12 operation during sleep the lcd module can operate during sleep. the selection is controlled by bit slpen of the lcdcon register. setting the slpen bit allows the lcd module to go to sleep. clearing the slpen bit allows the module to continue to operate during sleep. if a sleep instruction is executed and slpen = 1 , the lcd module will cease all functions and go into a very low-current consumption mode. the module will stop operation immediately and drive the minimum lcd voltage on both segment and common lines. figure 27-20 shows this operation. the lcd module can be configured to operate during sleep. the selection is controlled by bit slpen of the lcdcon register. clearing slpen and correctly con- figuring the lcd module clock will allow the lcd mod- ule to operate during sleep. setting slpen and correctly executing the lcd module shutdown will disable the lcd module during sleep and save power. if a sleep instruction is executed and slpen = 1 , the lcd module will immediately cease all functions, drive the outputs to vss and go into a very low-current mode. the sleep instruction should only be executed after the lcd module has been disabled and the current cycle completed, thus ensuring that there are no dc voltages on the glass. to disable the lcd module, clear the lcden bit. the lcd module will complete the disabling process after the current frame, clear the lcda bit and optionally cause an interrupt. the steps required to properly enter sleep with the lcd disabled are: ? clear lcden ? wait for lcda = 0 either by polling or by interrupt ? execute sleep if slpen = 0 and sleep is executed while the lcd module clock source is f osc /4, then the lcd module will halt with the pin driving the last lcd voltage pat- tern. prolonged exposure to a fixed lcd voltage pat- tern will cause damage to the lcd glass. to prevent lcd glass damage, either perform the proper lcd module shutdown prior to sleep, or change the lcd module clock to allow the lcd module to continue operation during sleep. if a sleep instruction is executed and slpen = 0 and the lcd module clock is either t1osc or lfintosc, the module will continue to display the current contents of the lcddata registers. while in sleep, the lcd data cannot be changed. if the lcdie bit is set, the device will wake from sleep on the next lcd frame boundary. the lcd module current consumption will not decrease in this mode; however, the overall device power consumption will be lower due to the shutdown of the cpu and other peripherals. table 27-8 shows the status of the lcd module during a sleep while using each of the three available clock sources. if a sleep instruction is executed and slpen = 0 , the module will continue to display the current contents of the lcddata registers. to allow the module to continue operation while in sleep, the clock source must be either the lfintosc or t1osc external oscillator. while in sleep, the lcd data cannot be changed. the lcd module current consumption will not decrease in this mode; however, the overall consumption of the device will be lower due to shut down of the core and other peripheral functions. table 27-8 shows the status of the lcd module during sleep while using each of the three available clock sources: table 27-8: lcd module status during sleep if lcd interrupts are being generated (type-b wave- form with a multiplex mode not static) and lcdie = 1 , the device will awaken from sleep on the next frame boundary. note: when the lcden bit is cleared, the lcd module will be disabled at the completion of frame. at this time, the port pins will revert to digital functionality. to minimize power consumption due to floating digital inputs, the lcd pins should be driven low using the port and tris registers. clock source slpen operational during sleep t1osc 0 yes 1 no lfintosc 0 yes 1 no f osc /4 0 no 1 no note: the lfintosc or external t1osc oscillator must be used to operate the lcd module during sleep.
pic16(l)f1946/1947 ds41414c-page 366 preliminary ? 2010-2011 microchip technology inc. figure 27-20: sleep entry/exit when slpen = 1 sleep instruction execution wake-up 2 frames v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 v 3 v 2 v 1 v 0 com0 com1 com2 seg0
? 2010-2011 microchip technology inc. preliminary ds41414c-page 367 pic16(l)f1946/1947 27.13 configuring the lcd module the following is the sequence of steps to configure the lcd module. 1. select the frame clock prescale using bits lp<3:0> of the lcdps register. 2. configure the appropriate pins to function as segment drivers using the lcdsen registers. 3. configure the lcd module for the following using the lcdcon register: - multiplex and bias mode, bits lmux<1:0> - timing source, bits cs<1:0> - sleep mode, bit slpen 4. write initial values to pixel data registers, lcddata0 through lcddata23. 5. clear lcd interrupt flag, lcdif bit of the pir2 register and if desired, enable the interrupt by setting bit lcdie of the pie2 register. 6. configure bias voltages by setting the lcdrl, lcdref and the associated anselx registers as needed. 7. enable the lcd module by setting bit lcden of the lcdcon register. 27.14 disabling the lcd module to disable the lcd module, write all ? 0 ?s to the lcdcon register. 27.15 lcd current consumption when using the lcd module the current consumption consists of the following three factors: ? oscillator selection ? lcd bias source ? capacitance of the lcd segments the current consumption of just the lcd module can be considered negligible compared to these other factors. 27.15.1 oscillator selection the current consumed by the clock source selected must be considered when using the lcd module. see section 30.0 ?electrical specifications? for oscillator current consumption information. 27.15.2 lcd bias source the lcd bias source, internal or external, can contrib- ute significantly to the current consumption. use the highest possible resistor values while maintaining contrast to minimize current. 27.15.3 capacitance of the lcd segments the lcd segments which can be modeled as capaci- tors which must be both charged and discharged every frame. the size of the lcd segment and its technology determines the segment?s capacitance.
pic16(l)f1946/1947 ds41414c-page 368 preliminary ? 2010-2011 microchip technology inc. table 27-9: summary of registers associated with lcd operation name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page intcon gie peie tmr0ie inte iocie tmr0if intf iocif 93 lcdcon lcden slpen werr ? cs<1:0> lmux<1:0> 337 lcdcst ? ? ? ? ? lcdcst<2:0> 340 lcddata0 seg7 com0 seg6 com0 seg5 com0 seg4 com0 seg3 com0 seg2 com0 seg1 com0 seg0 com0 341 lcddata1 seg15 com0 seg14 com0 seg13 com0 seg12 com0 seg11 com0 seg10 com0 seg9 com0 seg8 com0 341 lcddata2 seg23 com0 seg22 com0 seg21 com0 seg20 com0 seg19 com0 seg18 com0 seg17 com0 seg16 com0 341 lcddata3 seg7 com1 seg6 com1 seg5 com1 seg4 com1 seg3 com1 seg2 com1 seg1 com1 seg0 com1 341 lcddata4 seg15 com1 seg14 com1 seg13 com1 seg12 com1 seg11 com1 seg10 com1 seg9 com1 seg8 com1 341 lcddata5 seg23 com1 seg22 com1 seg21 com1 seg20 com1 seg19 com1 seg18 com1 seg17 com1 seg16 com1 341 lcddata6 seg7 com2 seg6 com2 seg5 com2 seg4 com2 seg3 com2 seg2 com2 seg1 com2 seg0 com2 341 lcddata7 seg15 com2 seg14 com2 seg13 com2 seg12 com2 seg11 com2 seg10 com2 seg9 com2 seg8 com2 341 lcddata8 seg23 com2 seg22 com2 seg21 com2 seg20 com2 seg19 com2 seg18 com2 seg17 com2 seg16 com2 341 lcddata9 seg7 com3 seg6 com3 seg5 com3 seg4 com3 seg3 com3 seg2 com3 seg1 com3 seg0 com3 341 lcddata10 seg15 com3 seg14 com3 seg13 com3 seg12 com3 seg11 com3 seg10 com3 seg9 com3 seg8 com3 341 lcddata11 seg23 com3 seg22 com3 seg21 com3 seg20 com3 seg19 com3 seg18 com3 seg17 com3 seg16 com3 341 lcddata12 seg31 com0 seg30 com0 seg29 com0 seg28 com0 seg27 com0 seg26 com0 seg25 com0 seg24 com0 341 lcddata13 seg39 com0 seg38 com0 seg37 com0 seg36 com0 seg35 com0 seg34 com0 seg33 com0 seg32 com0 341 lcddata14 ? ? seg45 com0 seg44 com0 seg43 com0 seg42 com0 seg41 com0 seg40 com0 341 lcddata15 seg31 com1 seg30 com1 seg29 com1 seg28 com1 seg27 com1 seg26 com1 seg25 com1 seg24 com1 341 lcddata16 seg39 com1 seg38 com1 seg37 com1 seg36 com1 seg35 com1 seg34 com1 seg33 com1 seg32 com1 341 lcddata17 ? ? seg45 com1 seg44 com1 seg43 com1 seg42 com1 seg41 com1 seg40 com1 341 lcddata18 seg31 com2 seg30 com2 seg29 com2 seg28 com2 seg27 com2 seg26 com2 seg25 com2 seg24 com2 341 lcddata19 seg39 com2 seg38 com2 seg37 com2 seg36 com2 seg35 com2 seg34 com2 seg33 com2 seg32 com2 341 lcddata20 ? ? seg45 com2 seg44 com2 seg43 com2 seg42 com2 seg41 com2 seg40 com2 341 lcddata21 seg31 com3 seg30 com3 seg29 com3 seg28 com3 seg27 com3 seg26 com3 seg25 com3 seg24 com3 341 legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by the lcd module.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 369 pic16(l)f1946/1947 lcddata22 seg39 com3 seg38 com3 seg37 com3 seg36 com3 seg35 com3 seg34 com3 seg33 com3 seg32 com3 341 lcddata23 ? ? seg45 com3 seg44 com3 seg43 com3 seg42 com3 seg41 com3 seg40 com3 341 lcdps wft biasmd lcda wa lp<3:0> 338 lcdref lcdire lcdirs lcdiri ? vlcd3pe vlcd2pe vlcd1pe ? 339 lcdrl lrlap<1:0> lrlbp<1:0> ? lrlat<2:0> 348 lcdse0 se<7:0> 341 lcdse1 se<15:8> 341 lcdse2 se<23:16> 341 lcdse3 se<31:24> 341 lcdse4 se<39:32> 341 lcdse5 ? ? se<45:40> 341 pie2 osfie c2ie c1ie eeie bclie lcdie c3ie ccp2ie 95 pir2 osfif c2if c1if eeif bclif lcdif c3if ccp2if 99 t1con tmr1cs<1:0> t1ckps<1:0> t1oscen t1sync ? tmr1on 205 table 27-9: summary of registers asso ciated with lcd operation (continued) name bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 register on page legend: ? = unimplemented location, read as ? 0 ?. shaded cells are not used by the lcd module.
pic16(l)f1946/1947 ds41414c-page 370 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 371 pic16(l)f1946/1947 28.0 in-circuit serial programming? (icsp?) icsp? programming allows customers to manufacture circuit boards with unprogrammed devices. programming can be done after the assembly process allowing the device to be programmed with the most recent firmware or a custom firmware. five pins are needed for icsp? programming: ? icspclk ? icspdat ?mclr /v pp ?v dd ?v ss in program/verify mode the program memory, user ids and the configuration words are programmed through serial communications. the icspdat pin is a bidirectional i/o used for transferring the serial data and the icspclk pin is the clock input. for more information on icsp? refer to the ? pic16f193x/lf193x/pic16f194x/lf194x memory programming specification ? (ds41397). 28.1 high-voltage programming entry mode the device is placed into high-voltage programming entry mode by holding the icspclk and icspdat pins low then raising the voltage on mclr /v pp to v ihh . some programmers produce v pp greater than v ihh (9.0v), an external circuit is required to limit the v pp voltage. see figure 28-1 for example circuit. figure 28-1: vpp limiter example circuit v ref v pp v dd v ss icsp_data icsp_clock nc rj11-6pin rj11-6pin r1 270 ohm to m p l a b ? icd 2 to tar g e t b o ar d 1 2 3 4 5 61 2 3 4 5 6 r2 r3 10k 1% 24k 1% u1 lm431bcmx a 2 3 6 7 8 a a a k nc nc 1 4 5
pic16(l)f1946/1947 ds41414c-page 372 preliminary ? 2010-2011 microchip technology inc. 28.2 low-voltage programming entry mode the low-voltage programming entry mode allows the pic16f/lf1946/47 devices to be programmed using v dd only, without high voltage. when the lvp bit of configuration word 2 is set to ? 1 ?, the low-voltage icsp programming entry is enabled. to disable the low-voltage icsp mode, the lvp bit must be programmed to ? 0 ?. entry into the low-voltage programming entry mode requires the following steps: 1. mclr is brought to v il . 2. a 32-bit key sequence is presented on icspdat, while clocking icspclk. once the key sequence is complete, mclr must be held at v il for as long as program/verify mode is to be maintained. if low-voltage programming is enabled (lvp = 1 ), the mclr reset function is automatically enabled and cannot be disabled. see section 6.3 ?mclr? for more information. the lvp bit can only be reprogrammed to ? 0 ? by using the high-voltage programming mode. 28.3 common programming interfaces connection to a target device is typically done through an icsp? header. a commonly found connector on development tools is the rj-11 in the 6p6c (6 pin, 6 connector) configuration. see figure 28-2 . figure 28-2: icd rj-11 style connector interface another connector often found in use with the pickit? programmers is a standard 6-pin header with 0.1 inch spacing. refer to figure 28-3 . figure 28-3: pickit? st yle connector interface note: the icd 2 produces a v pp voltage greater than the maximum v pp specification of the pic16f/lf1946/47. 1 2 3 4 5 6 target bottom side pc board v pp /mclr v ss icspclk v dd icspdat nc pin description* 1 = v pp /mclr 2 = v dd target 3 = v ss (ground) 4 = icspdat 5 = icspclk 6 = no connect 1 2 3 4 5 6 * the 6-pin header (0.100" spacing) accepts 0.025" square pins. pin description* 1 = v pp /mclr 2 = v dd target 3 = v ss (ground) 4 = icspdat 5 = icspclk 6 = no connect pin 1 indicator
? 2010-2011 microchip technology inc. preliminary ds41414c-page 373 pic16(l)f1946/1947 for additional interface recommendations, refer to your specific device programmer manual prior to pcb design. it is recommended that isolation devices be used to separate the programming pins from other circuitry. the type of isolation is highly dependent on the specific application and may include devices such as resistors, diodes, or even jumpers. see figure 28-4 for more information. figure 28-4: typical connect ion for icsp? programming v dd v pp v ss external device to be data clock v dd mclr /v pp v ss icspdat icspclk * * * to normal connections * isolation devices (as required). programming signals programmed v dd
pic16(l)f1946/1947 ds41414c-page 374 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 375 pic16(l)f1946/1947 29.0 instruction set summary each pic16 instruction is a 14-bit word containing the operation code (opcode) and all required operands. the opcodes are broken into three broad categories. ? byte oriented ? bit oriented ? literal and control the literal and control category contains the most var- ied instruction word format. table 29-3 lists the instructions recognized by the mpasm tm assembler. all instructions are executed within a single instruction cycle, with the following exceptions, which may take two or three cycles: ? subroutine takes two cycles ( call , callw ) ? returns from interrupts or subroutines take two cycles ( return , retlw , retfie ) ? program branching takes two cycles ( goto , bra , brw , btfss , btfsc , decfsz , incsfz ) ? one additional instruction cycle will be used when any instruction references an indirect file register and the file select register is pointing to program memory. one instruction cycle consists of 4 oscillator cycles; for an oscillator frequency of 4 mhz, this gives a nominal instruction execution rate of 1 mhz. all instruction examples use the format ? 0xhh ? to represent a hexadecimal number, where ? h ? signifies a hexadecimal digit. 29.1 read-modify-write operations any instruction that specifies a file register as part of the instruction performs a read-modify-write (r-m-w) operation. the register is read, the data is modified, and the result is stored according to either the instruc- tion, or the destination designator ?d?. a read operation is performed on a register even if the instruction writes to that register. table 29-1: opcode field descriptions table 29-2: abbreviation descriptions field description f register file address (0x00 to 0x7f) w working register (accumulator) b bit address within an 8-bit file register k literal field, constant data or label x don?t care location (= 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. d destination select; d = 0 : store result in w , d = 1 : store result in file register f. default is d = 1. n fsr or indf number. (0-1) mm pre-post increment-decrement mode selection field description pc program counter to time-out bit c carry bit dc digit carry bit z zero bit pd power-down bit
pic16(l)f1946/1947 ds41414c-page 376 preliminary ? 2010-2011 microchip technology inc. figure 29-1: general format for instructions byte-oriented file register operations 13 8 7 6 0 d = 0 for destination w opcode d f (file #) d = 1 for destination f f = 7-bit file register address bit-oriented file register operations 13 10 9 7 6 0 opcode b (bit #) f (file #) b = 3-bit bit address f = 7-bit file register address literal and control operations 13 8 7 0 opcode k (literal) k = 8-bit immediate value 13 11 10 0 opcode k (literal) k = 11-bit immediate value general call and goto instructions only movlp instruction only 13 5 4 0 opcode k (literal) k = 5-bit immediate value movlb instruction only 13 9 8 0 opcode k (literal) k = 9-bit immediate value bra instruction only fsr offset instructions 13 7 6 5 0 opcode n k (literal) n = appropriate fsr fsr increment instructions 13 7 6 0 opcode k (literal) k = 7-bit immediate value 13 3 2 1 0 opcode n m (mode) n = appropriate fsr m = 2-bit mode value k = 6-bit immediate value 13 0 opcode opcode only
? 2010-2011 microchip technology inc. preliminary ds41414c-page 377 pic16(l)f1946/1947 table 29-3: pic16f/lf1946/47 enhanced instruction set mnemonic, operands description cycles 14-bit opcode status affected notes msb lsb byte-oriented file register operations addwf addwfc andwf asrf lslf lsrf clrf clrw comf decf incf iorwf movf movwf rlf rrf subwf subwfb swapf xorwf f, d f, d f, d f, d f, d f, d f ? f, d f, d f, d f, d f, d f f, d f, d f, d f, d f, d f, d add w and f add with carry w and f and w with f arithmetic right shift logical left shift logical right shift clear f clear w complement f decrement f increment f inclusive or w with f move f move w to f rotate left f through carry rotate right f through carry subtract w from f subtract with borrow w from f swap nibbles in f exclusive or w with f 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 00 11 00 11 11 11 00 00 00 00 00 00 00 00 00 00 00 11 00 00 0111 1101 0101 0111 0101 0110 0001 0001 1001 0011 1010 0100 1000 0000 1101 1100 0010 1011 1110 0110 dfff dfff dfff dfff dfff dfff lfff 0000 dfff dfff dfff dfff dfff 1fff dfff dfff dfff dfff dfff dfff ffff ffff ffff ffff ffff ffff ffff 00xx ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff ffff c, dc, z c, dc, z z c, z c, z c, z z z z z z z z c c c, dc, z c, dc, z z 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 byte oriented skip operations decfsz incfsz f, d f, d decrement f, skip if 0 increment f, skip if 0 1(2) 1(2) 00 00 1011 1111 dfff dfff ffff ffff 1, 2 1, 2 bit-oriented file register operations bcf bsf f, b f, b bit clear f bit set f 1 1 01 01 00bb 01bb bfff bfff ffff ffff 2 2 bit-oriented skip operations btfsc btfss f, b f, b bit test f, skip if clear bit test f, skip if set 1 (2) 1 (2) 01 01 10bb 11bb bfff bfff ffff ffff 1, 2 1, 2 literal operations addlw andlw iorlw movlb movlp movlw sublw xorlw k k k k k k k k add literal and w and literal with w inclusive or literal with w move literal to bsr move literal to pclath move literal to w subtract w from literal exclusive or literal with w 1 1 1 1 1 1 1 1 11 11 11 00 11 11 11 11 1110 1001 1000 0000 0001 0000 1100 1010 kkkk kkkk kkkk 001k 1kkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk c, dc, z z z c, dc, z z note 1: 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 . 2: if this instruction addresses an indf register and the msb of the corresponding fsr is set, this instruction will require one additional instruction cycle.
pic16(l)f1946/1947 ds41414c-page 378 preliminary ? 2010-2011 microchip technology inc. table 29-3: pic16f/lf1946/47 enhanced instruction set (continued) mnemonic, operands description cycles 14-bit opcode status affected notes msb lsb control operations bra brw call callw goto retfie retlw return k ? k ? k k k ? relative branch relative branch with w call subroutine call subroutine with w go to address return from interrupt return with literal in w return from subroutine 2 2 2 2 2 2 2 2 11 00 10 00 10 00 11 00 001k 0000 0kkk 0000 1kkk 0000 0100 0000 kkkk 0000 kkkk 0000 kkkk 0000 kkkk 0000 kkkk 1011 kkkk 1010 kkkk 1001 kkkk 1000 inherent operations clrwdt nop option reset sleep tris ? ? ? ? ? f clear watchdog timer no operation load option_reg register with w software device reset go into standby mode load tris register with w 1 1 1 1 1 1 00 00 00 00 00 00 0000 0000 0000 0000 0000 0000 0110 0000 0110 0000 0110 0110 0100 0000 0010 0001 0011 0fff to , pd to , pd c-compiler optimized addfsr moviw movwi n, k n mm k[n] n mm k[n] add literal k to fsrn move indirect fsrn to w with pre/post inc/dec modifier, mm move indfn to w, indexed indirect. move w to indirect fsrn with pre/post inc/dec modifier, mm move w to indfn, indexed indirect. 1 1 1 1 1 11 00 11 00 11 0001 0000 1111 0000 1111 0nkk 0001 0nkk 0001 1nkk kkkk 0nmm kkkk 1nmm kkkk z z 2, 3 2 2, 3 2 note 1: 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 . 2: if this instruction addresses an indf register and the msb of the corresponding fsr is set, this instruction will require one additional instruction cycle. 3: see table in the moviw and movwi instruction descriptions.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 379 pic16(l)f1946/1947 29.2 instruction descriptions addfsr add literal to fsrn syntax: [ label ] addfsr fsrn, k operands: -32 ? k ? 31 n ? [ 0, 1] operation: fsr(n) + k ? fsr(n) status affected: none description: the signed 6-bit literal ?k? is added to the contents of the fsrnh:fsrnl register pair. fsrn is limited to the range 0000h - ffffh. moving beyond these bounds will cause the fsr to wrap around. addlw add literal and w syntax: [ label ] addlw k operands: 0 ? k ? 255 operation: (w) + k ? (w) status affected: c, dc, z description: the contents of the w register are added to the eight-bit literal ?k? and the result is placed in the w register. addwf add w and f syntax: [ label ] addwf f,d operands: 0 ? f ? 127 d ??? 0 , 1 ? operation: (w) + (f) ? (destination) status affected: c, dc, z description: add the contents of the w register with register ?f?. if ?d? is ? 0 ?, the result is stored in the w register. if ?d? is ? 1 ?, the result is stored back in register ?f?. addwfc add w and carry bit to f syntax: [ label ] addwfc f {,d} operands: 0 ? f ? 127 d ?? [0,1] operation: (w) + (f) + (c) ? dest status affected: c, dc, z description: add w, the carry flag and data mem- ory 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?. andlw and literal with w syntax: [ label ] andlw k operands: 0 ? k ? 255 operation: (w) .and. (k) ? (w) status affected: z description: the contents of w register are and?ed with the eight-bit literal ?k?. the result is placed in the w register. andwf and w with f syntax: [ label ] andwf f,d operands: 0 ? f ? 127 d ??? 0 , 1 ? operation: (w) .and. (f) ? (destination) status affected: z description: and the w register with register ?f?. if ?d? is ? 0 ?, the result is stored in the w register. if ?d? is ? 1 ?, the result is stored back in register ?f?. asrf arithmetic right shift syntax: [ label ] asrf f {,d} operands: 0 ? f ? 127 d ?? [0,1] operation: (f<7>) ? dest<7> (f<7:1>) ? dest<6:0>, (f<0>) ? c, status affected: c, z description: the contents of register ?f? are shifted one bit to the right through the carry flag. the msb remains unchanged. if ?d? is ? 0 ?, the result is placed in w. if ?d? is ? 1 ?, the result is stored back in reg- ister ?f?. register f c
pic16(l)f1946/1947 ds41414c-page 380 preliminary ? 2010-2011 microchip technology inc. bcf bit clear f syntax: [ label ] bcf f,b operands: 0 ? f ? 127 0 ? b ? 7 operation: 0 ? (f) status affected: none description: bit ?b? in register ?f? is cleared. bra relative branch syntax: [ label ] bra label [ label ] bra $+k operands: -256 ? label - pc + 1 ? 255 -256 ? k ? 255 operation: (pc) + 1 + k ? pc status affected: none description: add the signed 9-bit literal ?k? to the pc. since the pc will have incre- mented to fetch the next instruction, the new address will be pc + 1 + k. this instruction is a two-cycle instruc- tion. this branch has a limited range. brw relative branch with w syntax: [ label ] brw operands: none operation: (pc) + (w) ? pc status affected: none description: add the contents of w (unsigned) to the pc. since the pc will have incre- mented to fetch the next instruction, the new address will be pc + 1 + (w). this instruction is a two-cycle instruc- tion. bsf bit set f syntax: [ label ] bsf f,b operands: 0 ? f ? 127 0 ? b ? 7 operation: 1 ? (f) status affected: none description: bit ?b? in register ?f? is set. btfsc bit test f, skip if clear syntax: [ label ] btfsc f,b operands: 0 ? f ? 127 0 ? b ? 7 operation: skip if (f) = 0 status affected: none description: if bit ?b? in register ?f? is ? 1 ?, the next instruction is executed. if bit ?b?, in register ?f?, is ? 0 ?, the next instruction is discarded, and a nop is executed instead, making this a 2-cycle instruction. btfss bit test f, skip if set syntax: [ label ] btfss f,b operands: 0 ? f ? 127 0 ? b < 7 operation: skip if (f) = 1 status affected: none description: if bit ?b? in register ?f? is ? 0 ?, the next instruction is executed. if bit ?b? is ? 1 ?, then the next instruction is discarded and a nop is executed instead, making this a 2-cycle instruction.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 381 pic16(l)f1946/1947 call call subroutine syntax: [ label ] call k operands: 0 ? k ? 2047 operation: (pc)+ 1 ? tos, k ? pc<10:0>, (pclath<4:3>) ? pc<12:11> status affected: none description: call subroutine. first, return address (pc + 1) is pushed onto the stack. the eleven-bit immediate address is loaded into pc bits <10:0>. the upper bits of the pc are loaded from pclath. call is a two-cycle instruc- tion. callw subroutine call with w syntax: [ label ] callw operands: none operation: (pc) +1 ? tos, (w) ? pc<7:0>, (pclath<6:0>) ?? pc<14:8> status affected: none description: subroutine call with w. first, the return address (pc + 1) is pushed onto the return stack. then, the con- tents of w is loaded into pc<7:0>, and the contents of pclath into pc<14:8>. callw is a two-cycle instruction. clrf clear f syntax: [ label ] clrf f operands: 0 ? f ? 127 operation: 00h ? (f) 1 ? z status affected: z description: the contents of register ?f? are cleared and the z bit is set. clrw clear w syntax: [ label ] clrw operands: none operation: 00h ? (w) 1 ? z status affected: z description: w register is cleared. zero bit (z) is set. clrwdt clear watchdog timer syntax: [ label ] clrwdt operands: none operation: 00h ? wdt 0 ? wdt prescaler, 1 ? to 1 ? pd status affected: to , pd description: clrwdt instruction resets the watch- dog timer. it also resets the prescaler of the wdt. status bits to and pd are set. comf complement f syntax: [ label ] comf f,d operands: 0 ? f ? 127 d ? [ 0 , 1 ] operation: (f ) ? (destination) status affected: z description: the contents of register ?f? are com- plemented. if ?d? is ? 0 ?, the result is stored in w. if ?d? is ? 1 ?, the result is stored back in register ?f?. decf decrement f syntax: [ label ] decf f,d operands: 0 ? f ? 127 d ? [ 0 , 1 ] operation: (f) - 1 ? (destination) status affected: z description: decrement register ?f?. if ?d? is ? 0 ?, the result is stored in the w register. if ?d? is ? 1 ?, the result is stored back in register ?f?.
pic16(l)f1946/1947 ds41414c-page 382 preliminary ? 2010-2011 microchip technology inc. decfsz decrement f, skip if 0 syntax: [ label ] decfsz f,d operands: 0 ? f ? 127 d ? [ 0 , 1 ] operation: (f) - 1 ? (destination); skip if result = 0 status affected: none description: the contents of register ?f? are decre- mented. if ?d? is ? 0 ?, the result is placed in the w register. if ?d? is ? 1 ?, the result is placed back in register ?f?. if the result is ? 1 ?, the next instruction is executed. if the result is ? 0 ?, then a nop is executed instead, making it a 2-cycle instruction. goto unconditional branch syntax: [ label ] goto k operands: 0 ? k ? 2047 operation: k ? pc<10:0> pclath<4:3> ? pc<12:11> status affected: none description: goto is an unconditional branch. the eleven-bit immediate value is loaded into pc bits <10:0>. the upper bits of pc are loaded from pclath<4:3>. goto is a two-cycle instruction. incf increment f syntax: [ label ] incf f,d operands: 0 ? f ? 127 d ? [ 0 , 1 ] operation: (f) + 1 ? (destination) status affected: z description: the contents of register ?f? are incre- mented. if ?d? is ? 0 ?, the result is placed in the w register. if ?d? is ? 1 ?, the result is placed back in register ?f?. incfsz increment f, skip if 0 syntax: [ label ] incfsz f,d operands: 0 ? f ? 127 d ? [ 0 , 1 ] operation: (f) + 1 ? (destination), skip if result = 0 status affected: none description: the contents of register ?f? are incre- mented. if ?d? is ? 0 ?, the result is placed in the w register. if ?d? is ? 1 ?, the result is placed back in register ?f?. if the result is ? 1 ?, the next instruction is executed. if the result is ? 0 ?, a nop is executed instead, making it a 2-cycle instruction. iorlw inclusive or literal with w syntax: [ label ] iorlw k operands: 0 ? k ? 255 operation: (w) .or. k ? (w) status affected: z description: the contents of the w register are or?ed with the eight-bit literal ?k?. the result is placed in the w register. iorwf inclusive or w with f syntax: [ label ] iorwf f,d operands: 0 ? f ? 127 d ? [ 0 , 1 ] operation: (w) .or. (f) ? (destination) status affected: z description: inclusive or the w register with regis- ter ?f?. if ?d? is ? 0 ?, the result is placed in the w register. if ?d? is ? 1 ?, the result is placed back in register ?f?.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 383 pic16(l)f1946/1947 lslf logical left shift syntax: [ label ] lslf f {,d} operands: 0 ? f ? 127 d ?? [0,1] operation: (f<7>) ? c (f<6:0>) ? dest<7:1> 0 ? dest<0> status affected: c, z description: the contents of register ?f? are shifted one bit to the left through the carry flag. a ? 0 ? is shifted into the lsb. if ?d? is ? 0 ?, the result is placed in w. if ?d? is ? 1 ?, the result is stored back in register ?f?. lsrf logical right shift syntax: [ label ] lslf f {,d} operands: 0 ? f ? 127 d ?? [0,1] operation: 0 ? dest<7> (f<7:1>) ? dest<6:0>, (f<0>) ? c, status affected: c, z description: the contents of register ?f? are shifted one bit to the right through the carry flag. a ? 0 ? is shifted into the msb. if ?d? is ? 0 ?, the result is placed in w. if ?d? is ? 1 ?, the result is stored back in register ?f?. register f 0 c register f c 0 movf move f syntax: [ label ] movf f,d operands: 0 ? f ? 127 d ? [ 0 , 1 ] operation: (f) ? (dest) status affected: z description: the contents of register f is moved to a destination dependent upon the status of d. if d = 0 , destination is w register. if d = 1 , the destination is file register f itself. d = 1 is useful to test a file register since status flag z is affected. words: 1 cycles: 1 example: movf fsr, 0 after instruction w = value in fsr register z= 1
pic16(l)f1946/1947 ds41414c-page 384 preliminary ? 2010-2011 microchip technology inc. moviw move indfn to w syntax: [ label ] moviw ++fsrn [ label ] moviw --fsrn [ label ] moviw fsrn++ [ label ] moviw fsrn-- [ label ] moviw k[fsrn] operands: n ? [ 0 , 1 ] mm ? [ 00 , 01 , 10 , 11 ] -32 ? k ? 31 operation: indfn ? w effective address is determined by ? fsr + 1 (preincrement) ? fsr - 1 (predecrement) ? fsr + k (relative offset) after the move, the fsr value will be either: ? fsr + 1 (all increments) ? fsr - 1 (all decrements) ? unchanged status affected: z mode syntax mm preincrement ++fsrn 00 predecrement --fsrn 01 postincrement fsrn++ 10 postdecrement fsrn-- 11 description: this instruction is used to move data between w and one of the indirect registers (indfn). before/after this move, the pointer (fsrn) is updated by pre/post incrementing/decrementing it. note: the indfn registers are not physical registers. any instruction that accesses an indfn register actually accesses the register at the address specified by the fsrn. fsrn is limited to the range 0000h - ffffh. incrementing/decrementing it beyond these bounds will cause it to wrap around. movlb move literal to bsr syntax: [ label ] movlb k operands: 0 ? k ? 15 operation: k ? bsr status affected: none description: the five-bit literal ?k? is loaded into the bank select register (bsr). movlp move literal to pclath syntax: [ label ] movlp k operands: 0 ? k ? 127 operation: k ? pclath status affected: none description: the seven-bit literal ?k? is loaded into the pclath register. movlw move literal to w syntax: [ label ] movlw k operands: 0 ? k ? 255 operation: k ? (w) status affected: none description: the eight-bit literal ?k? is loaded into w register. the ?don?t cares? will assem- ble as ? 0 ?s. words: 1 cycles: 1 example: movlw 0x5a after instruction w = 0x5a movwf move w to f syntax: [ label ] movwf f operands: 0 ? f ? 127 operation: (w) ? (f) status affected: none description: move data from w register to register ?f?. words: 1 cycles: 1 example: movwf option before instruction option = 0xff w = 0x4f after instruction option = 0x4f w = 0x4f
? 2010-2011 microchip technology inc. preliminary ds41414c-page 385 pic16(l)f1946/1947 movwi move w to indfn syntax: [ label ] movwi ++fsrn [ label ] movwi --fsrn [ label ] movwi fsrn++ [ label ] movwi fsrn-- [ label ] movwi k[fsrn] operands: n ? [ 0 , 1 ] mm ? [ 00 , 01 , 10 , 11 ] -32 ? k ? 31 operation: w ? indfn effective address is determined by ? fsr + 1 (preincrement) ? fsr - 1 (predecrement) ? fsr + k (relative offset) after the move, the fsr value will be either: ? fsr + 1 (all increments) ? fsr - 1 (all decrements) unchanged status affected: none mode syntax mm preincrement ++fsrn 00 predecrement --fsrn 01 postincrement fsrn++ 10 postdecrement fsrn-- 11 description: this instruction is used to move data between w and one of the indirect registers (indfn). before/after this move, the pointer (fsrn) is updated by pre/post incrementing/decrementing it. note: the indfn registers are not physical registers. any instruction that accesses an indfn register actually accesses the register at the address specified by the fsrn. fsrn is limited to the range 0000h - ffffh. incrementing/decrementing it beyond these bounds will cause it to wrap around. the increment/decrement operation on fsrn will not affect any status bits. nop no operation syntax: [ label ] nop operands: none operation: no operation status affected: none description: no operation. words: 1 cycles: 1 example: nop option load option_reg register with w syntax: [ label ] option operands: none operation: (w) ? option_reg status affected: none description: move data from w register to option_reg register. reset software reset syntax: [ label ] reset operands: none operation: execute a device reset. resets the nri flag of the pcon register. status affected: none description: this instruction provides a way to execute a hardware reset by soft- ware.
pic16(l)f1946/1947 ds41414c-page 386 preliminary ? 2010-2011 microchip technology inc. retfie return from interrupt syntax: [ label ] retfie operands: none operation: tos ? pc, 1 ? gie status affected: none description: return from interrupt. stack is poped and top-of-stack (tos) is loaded in the pc. interrupts are enabled by setting global interrupt enable bit, gie (intcon<7>). this is a two-cycle instruction. words: 1 cycles: 2 example: retfie after interrupt pc = tos gie = 1 retlw return with literal in w syntax: [ label ] retlw k operands: 0 ? k ? 255 operation: k ? (w); tos ? pc status affected: none description: the w register is loaded with the eight bit literal ?k?. the program counter is loaded from the top of the stack (the return address). this is a two-cycle instruction. words: 1 cycles: 2 example: table call table;w contains table ;offset value ? ;w now has table value ? ? addwf pc ;w = offset retlw k1 ;begin table retlw k2 ; ? ? ? retlw kn ; end of table before instruction w = 0x07 after instruction w = value of k8 return return from subroutine syntax: [ label ] return operands: none operation: tos ? pc status affected: none description: return from subroutine. the stack is poped and the top of the stack (tos) is loaded into the program counter. this is a two-cycle instruction. rlf rotate left f through carry syntax: [ label ] rlf f,d operands: 0 ? f ? 127 d ? [ 0 , 1 ] operation: see description below status affected: c 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 the w register. if ?d? is ? 1 ?, the result is stored back in register ?f?. words: 1 cycles: 1 example: rlf reg1,0 before instruction reg1 = 1110 0110 c=0 after instruction reg1 = 1110 0110 w = 1100 1100 c=1 register f c
? 2010-2011 microchip technology inc. preliminary ds41414c-page 387 pic16(l)f1946/1947 rrf rotate right f through carry syntax: [ label ] rrf f,d operands: 0 ? f ? 127 d ? [ 0 , 1 ] operation: see description below status affected: c 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 the w register. if ?d? is ? 1 ?, the result is placed back in register ?f?. sleep enter sleep mode syntax: [ label ]sleep operands: none operation: 00h ? wdt, 0 ? wdt prescaler, 1 ? to , 0 ? pd status affected: to , pd description: the power-down status bit, pd is cleared. time-out status bit, to is set. watchdog timer and its pres- caler are cleared. the processor is put into sleep mode with the oscillator stopped. register f c sublw subtract w from literal syntax: [ label ]sublw k operands: 0 ?? k ?? 255 operation: k - (w) ??? w) status affected: c, dc, z description: the w register is subtracted (2?s com- plement method) from the eight-bit literal ?k?. the result is placed in the w register. subwf subtract w from f syntax: [ label ] subwf f,d operands: 0 ?? f ?? 127 d ? [ 0 , 1 ] operation: (f) - (w) ??? destination) status affected: c, dc, z description: subtract (2?s complement method) w register from register ?f?. if ?d? is ? 0 ?, the result is stored in the w register. if ?d? is ? 1 ?, the result is stored back in register ?f. subwfb subtract w from f with borrow syntax: subwfb f {,d} operands: 0 ? f ? 127 d ? [0,1] operation: (f) ? (w) ? (b ) ?? dest status affected: c, dc, z description: subtract w and the borrow flag (carry) from register ?f? (2?s comple- ment method). if ?d? is ? 0 ?, the result is stored in w. if ?d? is ? 1 ?, the result is stored back in register ?f?. c = 0 w ? k c = 1 w ? k dc = 0 w<3:0> ? k<3:0> dc = 1 w<3:0> ? k<3:0> c = 0 w ? f c = 1 w ? f dc = 0 w<3:0> ? f<3:0> dc = 1 w<3:0> ? f<3:0>
pic16(l)f1946/1947 ds41414c-page 388 preliminary ? 2010-2011 microchip technology inc. swapf swap nibbles in f syntax: [ label ] swapf f,d operands: 0 ? f ? 127 d ? [ 0 , 1 ] operation: (f<3:0>) ? (destination<7:4>), (f<7:4>) ? (destination<3:0>) status affected: none description: the upper and lower nibbles of regis- ter ?f? are exchanged. if ?d? is ? 0 ?, the result is placed in the w register. if ?d? is ? 1 ?, the result is placed in register ?f?. tris load tris register with w syntax: [ label ] tris f operands: 5 ? f ? 7 operation: (w) ? tris register ?f? status affected: none description: move data from w register to tris register. when ?f? = 5, trisa is loaded. when ?f? = 6, trisb is loaded. when ?f? = 7, trisc is loaded. xorlw exclusive or literal with w syntax: [ label ] xorlw k operands: 0 ?? k ?? 255 operation: (w) .xor. k ??? w) status affected: z description: the contents of the w register are xor?ed with the eight-bit literal ?k?. the result is placed in the w register. xorwf exclusive or w with f syntax: [ label ] xorwf f,d operands: 0 ? f ? 127 d ? [ 0 , 1 ] operation: (w) .xor. (f) ??? destination) status affected: z description: exclusive or the contents of the w register with register ?f?. if ?d? is ? 0 ?, the result is stored in the w register. if ?d? is ? 1 ?, the result is stored back in regis- ter ?f?.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 389 pic16(l)f1946/1947 30.0 electrical specifications absolute maximum ratings (?) ambient temperature under bias................................................................................................. ...... -40c to +125c storage temperature ............................................................................................................ ............ -65c to +150c voltage on v dd with respect to v ss , pic16f1946/47 ........................................................................ -0.3v to +6.5v voltage on v cap pin with respect to v ss .............................................................................................. -0.3v to +4.0v voltage on v dd with respect to v ss , pic16lf1946/47 ...................................................................... -0.3v to +4.0v voltage on mclr with respect to vss ................................................................................................. -0.3v to +9.0v voltage on all other pins with respect to v ss ........................................................................... -0.3v to (v dd + 0.3v) total power dissipation (1) ............................................................................................................................... 800 mw maximum current out of v ss pin, -40c ? t a ? +85c for industrial............................................................... 425 ma maximum current out of v ss pin, -40c ? t a ? +125c for extended ............................................................ 175 ma maximum current into v dd pin, -40c ? t a ? +85c for industrial.................................................................. 425 ma maximum current into v dd pin, -40c ? t a ? +125c for extended ............................................................... 175 ma clamp current, i k (v pin < 0 or v pin > v dd ) ??????????????????????????????????????????????????????????????? ??????????????????????????????????????????????????? 20 ma maximum output current sunk by any i/o pin..................................................................................... ............... 25 ma maximum output current sourced by any i/o pin .................................................................................. ............ 25 ma note 1: power dissipation is calculated as follows: p dis = v dd x {i dd ? ? i oh } + ? {(v dd ? v oh ) x i oh } + ? (v o l 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 above maximum rating conditions for extended periods may affect device reliability.
pic16(l)f1946/1947 ds41414c-page 390 preliminary ? 2010-2011 microchip technology inc. figure 30-1: pic16f1946/47 voltage frequency graph, -40c ? t a ?? +125c figure 30-2: pic16lf1946/47 vo ltage frequency graph, -40c ? t a ?? +125c note 1: the shaded region indicates the permissible combinations of voltage and frequency. 2: refer to table 30-1 for each oscillator mode?s supported frequencies. 1.8 0 2.5 frequency (mhz) v dd (v) 432 10 16 5.5 note 1: the shaded region indicates the permissible combinations of voltage and frequency. 2: refer to table 30-1 for each oscillator mode?s supported frequencies. 1.8 0 2.5 frequency (mhz) v dd (v) 432 10 16 3.6
? 2010-2011 microchip technology inc. preliminary ds41414c-page 391 pic16(l)f1946/1947 figure 30-3: hfintosc frequency accuracy over device v dd and temperature 125 25 2.0 0 60 85 v dd (v) 4.0 5.0 4.5 temperature ( c ) 2.5 3.0 3.5 5.5 1.8 -40 -20 5% 2% 5% 3%
pic16(l)f1946/1947 ds41414c-page 392 preliminary ? 2010-2011 microchip technology inc. 30.1 dc characteristics: pic16f/lf1946/47-i/e (industrial, extended) standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended pic16f1946/47 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 d001 v dd supply voltage pic16lf1946/47 1.8 2.5 ? ? 3.6 3.6 v v f osc ? 16 mhz: f osc ? 32 mhz ( note 2 ) d001 pic16f1946/47 1.8 2.5 ? ? 5.5 5.5 v v f osc ? 16 mhz: f osc ? 32 mhz ( note 2 ) d002* v dr ram data retention voltage (1) pic16lf1946/47 1.5 ? ? v device in sleep mode d002* pic16f1946/47 1.7 ? ? v device in sleep mode v por * power-on reset release voltage ?1.6? v v porr * power-on reset rearm voltage pic16lf1946/47 ? 0.8 ? v device in sleep mode pic16f1946/47 ? 1.7 ? v device in sleep mode d003 v adfvr fixed voltage reference voltage for adc -8 ? ? ? ? ? ? ? ? ? ? ? 6 4 ? ? 4 4 % 1.024v, v dd ? 2.5v 2.048v, v dd ? 2.5v 4.096v, v dd ? 4.75v d003a v cdafvr fixed voltage reference voltage for comparator and dac -11 ? ? ? ? ? ? ? ? ? ? ? 7 ? ? ? 4 4 % 1.024v, v dd ? 2.5v 2.048v, v dd ? 2.5v 4.096v, v dd ? 4.75v d003b v lcdfvr fixed voltage reference voltage for lcd bias, initial accuracy -11 ? ? ? 10 9 % 3.072v, v dd ? 3.6v d004* s vdd v dd rise rate to ensure internal power-on reset signal 0.05 ? ? v/ms see section 6.1 ?power-on reset (por)? for details. * these parameters are characterized but not tested. ? 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: this is the limit to which v dd can be lowered in sleep mode without losing ram data. 2: pll required for 32 mhz operation.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 393 pic16(l)f1946/1947 figure 30-4: por and por rearm with slow rising v dd v dd v por v porr v ss v ss npor t por (3) por rearm note 1: when npor is low, the device is held in reset. 2: t por 1 ? s typical. 3: t vlow 2.7 ? s typical. t vlow (2)
pic16(l)f1946/1947 ds41414c-page 394 preliminary ? 2010-2011 microchip technology inc. 30.2 dc characteristics: pic16f/lf1946/47-i/e (industrial, extended) pic16lf1946/47 standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended pic16f1946/47 standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device characteristics min. typ? max. units conditions v dd note supply current (i dd ) (1, 2) d009 ldo regulator ? 350 ? ? a ? hs, ec or hfintosc clock modes with v cap pin disabled ? 50 ? ? a ? ? 30 ? ? a ? ? 5 ? ? a ? lp/lfintosc clock mode or sleep (requires fvr and bor to be disabled) d010 ? 5.0 11 ? a1.8f osc = 32 khz lp oscillator mode ( note 4 ) , -40c ? t a ? +85c ?6.0 13 ? a3.0 d010 ? 24 38 ? a 1.8 f osc = 32 khz lp oscillator mode ( note 4, 5 ) , -40c ? t a ? +85c ? 30 43 ? a 3.0 ? 32 48 ? a 5.0 d010a ? 7.0 23 ? a1.8 f osc = 32 khz lp oscillator mode ( note 4 ) -40c ? t a ? +125c ?9.0 27 ? a3.0 d010a ? 24 68 ? a 1.8 f osc = 32 khz lp oscillator mode ( note 4, 5 ) -40c ? t a ? +125c ? 30 88 ? a 3.0 ? 32 95 ? a 5.0 d011 ? 60 105 ? a1.8f osc = 1 mhz xt oscillator mode ? 120 190 ? a3.0 d011 ? 95 130 ? a 1.8 f osc = 1 mhz xt oscillator mode ( note 5 ) ? 170 220 ? a 3.0 ? 190 270 ? a 5.0 d012 ? 160 300 ? a1.8f osc = 4 mhz xt oscillator mode ? 300 500 ? a3.0 d012 ? 200 330 ? a 1.8 f osc = 4 mhz xt oscillator mode ( note 5 ) ? 300 500 ? a 3.0 ? 400 650 ? a 5.0 note 1: the test conditions for all i dd measurements in active operation mode ar e: osc1 = external square wave, from rail-to-rail; all i/o pins tri-stated, pulled to v dd ; mclr = v dd ; wdt disabled. 2: the supply current is mainly a function of the operating voltage and frequency. other factors, such as i/o pin loading and switching rate, oscillator type, internal code execution pa ttern and temperature, also have an impact on the current consumption. 3: for rc oscillator configurations, current through r ext is not included. the current through the resistor can be extended by the formula i r = v dd /2r ext (ma) with r ext in k ?? 4: fvr and bor are disabled. 5: 0.1 ? f capacitor on v cap (rf0). 6: 8 mhz crystal oscillator with 4x pll enabled.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 395 pic16(l)f1946/1947 supply current (i dd ) (1, 2) d013 ? 15 40 ? a1.8f osc = 500 khz ec oscillator low-power mode ?30 75 ? a3.0 d013 ? 30 60 ? a 1.8 f osc = 500 khz ec oscillator low-power mode ( note 5 ) ? 45 85 ? a 3.0 ? 50 90 ? a 5.0 d014 ? 140 250 ? a1.8f osc = 4 mhz ec oscillator mode medium power mode ? 270 400 ? a3.0 d014 ? 160 270 ? a 1.8 f osc = 4 mhz ec oscillator mode ( note 5 ) medium power mode ? 270 430 ? a 3.0 ? 320 500 ? a 5.0 d015 ? 2.0 3.2 ma 3.0 f osc = 32 mhz ec oscillator high-power mode ?2.3 3.9 ma 3.6 d015 ? 2.0 3.2 ma 3.0 f osc = 32 mhz ec oscillator high-power mode ( note 5 ) ? 2.2 3.9 ma 5.0 d016 ? 3.0 11 ? a1.8f osc = 32 khz, lfintosc mode ( note 4 ) -40c ? t a ? +85c ?5.0 13 ? a3.0 d016 ? 24 38 ? a 1.8 f osc = 32 khz, lfintosc mode ( note 4, 5 ) -40c ? t a ? +85c ? 30 43 ? a 3.0 ? 32 48 ? a 5.0 30.2 dc characteristics: pic16f/lf1946/47-i/e (industrial, extended) (continued) pic16lf1946/47 standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended pic16f1946/47 standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device characteristics min. typ? max. units conditions v dd note note 1: 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 disabled. 2: the supply current is mainly a function of the operating voltage and frequency. other factors, such as i/o pin loading and switching rate, oscillator type, internal code execution pa ttern and temperature, also have an impact on the current consumption. 3: for rc oscillator configurations, current through r ext is not included. the current through the resistor can be extended by the formula i r = v dd /2r ext (ma) with r ext in k ?? 4: fvr and bor are disabled. 5: 0.1 ? f capacitor on v cap (rf0). 6: 8 mhz crystal oscillator with 4x pll enabled.
pic16(l)f1946/1947 ds41414c-page 396 preliminary ? 2010-2011 microchip technology inc. d017 supply current (i dd ) (1, 2) ? 100 200 ? a1.8f osc = 500 khz mfintosc mode ? 120 230 ? a3.0 d017 ? 110 210 ? a 1.8 f osc = 500 khz mfintosc mode ( note 5 ) ? 120 240 ? a 3.0 ? 160 290 ? a 5.0 d018 ? 0.5 1.1 ma 1.8 f osc = 8 mhz hfintosc mode ?0.8 1.6 ma 3.0 d018 ? 0.5 1.2 ma 1.8 f osc = 8 mhz hfintosc mode ( note 5 ) ? 0.8 1.7 ma 3.0 ? 0.9 1.8 ma 5.0 d019 ? 0.8 1.5 ma 1.8 f osc = 16 mhz hfintosc mode ?1.2 2.3 ma 3.0 d019 ? 0.8 1.6 ma 1.8 f osc = 16 mhz hfintosc mode ( note 5 ) ? 1.2 2.4 ma 3.0 ? 1.4 2.5 ma 5.0 ?2.1 3.6 ma 3.0 f osc = 32 mhz hfintosc mode ?2.3 4.3 ma 3.6 ? 2.1 3.7 ma 3.0 f osc = 32 mhz hfintosc mode ? 2.2 4.1 ma 5.0 d020 ? 150 260 ? a1.8f osc = 4 mhz extrc mode ( note 3 ) ? 270 425 ? a3.0 d020 ? 170 280 ? a 1.8 f osc = 4 mhz extrc mode ( note 3, note 5 ) ? 290 450 ? a 3.0 ? 320 500 ? a 5.0 d021 ? 2.1 3.6 ma 3.0 f osc = 32 mhz hs oscillator mode ( note 6 ) ?2.3 4.3 ma 3.6 d021 ? 2.1 3.7 ma 3.0 f osc = 32 mhz hs oscillator mode ( note 5, note 6 ) ? 2.2 4.1 ma 5.0 30.2 dc characteristics: pic16f/lf1946/47-i/e (industrial, extended) (continued) pic16lf1946/47 standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended pic16f1946/47 standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device characteristics min. typ? max. units conditions v dd note note 1: the test conditions for all i dd measurements in active operation mode ar e: osc1 = external square wave, from rail-to-rail; all i/o pins tri-stated, pulled to v dd ; mclr = v dd ; wdt disabled. 2: the supply current is mainly a function of the operating voltage and frequency. other factors, such as i/o pin loading and switching rate, oscillator type, internal code execution pa ttern and temperature, also have an impact on the current consumption. 3: for rc oscillator configurations, current through r ext is not included. the current through the resistor can be extended by the formula i r = v dd /2r ext (ma) with r ext in k ?? 4: fvr and bor are disabled. 5: 0.1 ? f capacitor on v cap (rf0). 6: 8 mhz crystal oscillator with 4x pll enabled.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 397 pic16(l)f1946/1947 30.3 dc characteristics: pic16f/lf1946/47-i/e (power-down) pic16lf1946/47 standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended pic16f1946/47 standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device characteristics min. typ? max. +85c max. +125c units conditions v dd note power-down base current (i pd ) (2) d023 ? 0.06 1.0 8.0 ? a 1.8 wdt, bor, fvr, and t1osc disabled, all peripherals inactive ? 0.08 2.0 9.0 ? a3.0 d023 ? 21 55 63 ? a 1.8 wdt, bor, fvr, and t1osc disabled, all peripherals inactive ? 25 58 78 ? a 3.0 ? 27 60 88 ? a 5.0 d024 ? 0.5 6.0 9.0 ? a 1.8 lpwdt current ( note 1 ) ?0.87.0 10 ? a3.0 d024 ? 23 57 65 ? a 1.8 lpwdt current ( note 1 ) ? 26 59 80 ? a 3.0 ? 28 61 90 ? a 5.0 d025 ? 15 28 30 ? a 1.8 fvr current ?15 30 33 ? a3.0 d025 ? 38 96 100 ? a 1.8 fvr current ( note 4 ) ? 45 110 120 ? a 3.0 ? 90 140 155 ? a 5.0 d026 ? 13 25 28 ? a 3.0 bor current ( note 1 ) d026 ? 40 110 120 ? a 3.0 bor current ( note 1, note 4 ) ? 87 140 155 ? a 5.0 d027 ? 0.6 5.0 9.0 ? a 1.8 t1osc current ( note 1 ) ?1.86.0 12 ? a3.0 d027 ? 22 57 60 ? a 1.8 t1osc current ( note 1 ) ? 29 62 70 ? a 3.0 ? 35 66 85 ? a 5.0 * these parameters are char acterized but not tested. ? data in ?typ? column is at 3.0v, 25c unless otherwise stated. these parameters are for design guidance only and are not tested. note 1: the peripheral current is the sum of the base i dd or i pd and the additional current consumed when this peripheral is enabled. the peripheral ? current can be determined by subtracting the base i dd or i pd current from this limit. max values should be used when calculating total current consumption. 2: 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 high-impedance state and tied to v dd . 3: a/d oscillator source is f rc . 4: 0.1 ? f capacitor on v cap (rf0).
pic16(l)f1946/1947 ds41414c-page 398 preliminary ? 2010-2011 microchip technology inc. power-down base current (i pd ) (2) d028 ? 0.1 5.0 8.0 ? a 1.8 a/d current ( note 1, note 3 ) , no conversion in progress ? 0.1 6.0 9.0 ? a3.0 d028 ? 22 56 63 ? a 1.8 a/d current ( note 1, note 3 ) , no conversion in progress ? 26 58 78 ? a 3.0 ? 27 61 88 ? a 5.0 d029 ? 250 ? ? ? a 1.8 a/d current ( note 1, note 3 ) , conversion in progress ?250 ? ? ? a3.0 d029 ? 280 ? ? ? a 1.8 a/d current ( note 1, note 3, note 4 ) , conversion in progress ? 280 ? ? ? a 3.0 ? 280 ? ? ? a 5.0 d030 ? 1 ? ? ? a 3.0 lcd bias ladder, low-power ?10 ? ? ? a 3.0 lcd bias ladder, medium-power ?75 ? ? ? a 3.0 lcd bias ladder, high-power d030 ? 1 ? ? ? a 5.0 lcd bias ladder, low-power ? 10 ? ? ? a 5.0 lcd bias ladder, medium-power ? 75 ? ? ? a 5.0 lcd bias ladder, high-power d031 ? 7.6 22 25 ? a 1.8 comparator, low power mode ? 8.0 23 27 ? a3.0 d031 ? 24 55 65 ? a 1.8 comparator, low power mode ? 26 58 80 ? a 3.0 ? 28 60 90 ? a 5.0 d032a* ? 2.0 ? ? ? a 1.8 cap sense, low-power mode cpsrm=0 ?3.0 ? ? ? a3.0 d032a* ? 23 ? ? ? a 1.8 cap sense, low-power mode cpsrm=0 ? 28 ? ? ? a 3.0 ? 30 ? ? ? a 5.0 30.3 dc characteristics: pic16f/lf1946/47-i/e (power-down) (continued) pic16lf1946/47 standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended pic16f1946/47 standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device characteristics min. typ? max. +85c max. +125c units conditions v dd note * these parameters are characterized but not tested. ? data in ?typ? column is at 3.0v, 25c unless otherwise stated. these parameters are for design guidance only and are not tested. note 1: the peripheral current is the sum of the base i dd or i pd and the additional current consumed when this peripheral is enabled. the peripheral ? current can be determined by subtracting the base i dd or i pd current from this limit. max values should be used when calculating total current consumption. 2: 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 high-impedance state and tied to v dd . 3: a/d oscillator source is f rc . 4: 0.1 ? f capacitor on v cap (rf0).
? 2010-2011 microchip technology inc. preliminary ds41414c-page 399 pic16(l)f1946/1947 d032b* power-down base current (i pd ) (2) ?80 ? ? ? a 1.8 cap sense, low power mode, cpsrm = 1 , includes fvr and dac current ?90 ? ? ? a3.0 d032b* ? 110 ? ? ? a 1.8 cap sense, low power mode, cpsrm = 1 , includes fvr and dac current ? 120 ? ? ? a 3.0 ? 130 ? ? ? a 5.0 d032c* ? 4 ? ? ? a 1.8 cap sense, medium power mode, cpsrm = 0 ?6 ? ? ? a3.0 d032c* ? 25 ? ? ? a 1.8 cap sense, medium power mode, cpsrm = 0 ? 30 ? ? ? a 3.0 ? 32 ? ? ? a 5.0 d032d* ? 90 ? ? ? a 1.8 cap sense, medium power mode, cpsrm = 1 , includes fvr and dac current ?120 ? ? ? a3.0 d032d* ? 120 ? ? ? a 1.8 cap sense, medium power mode, cpsrm = 1 , includes fvr and dac current ? 140 ? ? ? a 3.0 ? 150 ? ? ? a 5.0 d032e* ? 12 ? ? ? a 1.8 cap sense, high power mode, cpsrm = 0 ?31 ? ? ? a3.0 d032e* ? 33 ? ? ? a 1.8 cap sense, high power mode, cpsrm = 0 ? 52 ? ? ? a 3.0 ? 62 ? ? ? a 5.0 d032f* ? 120 ? ? ? a 1.8 cap sense, high power mode, cpsrm = 1 , includes fvr and dac current ?160 ? ? ? a3.0 d032f* ? 150 ? ? ? a 1.8 cap sense, high power mode, cpsrm = 1 , includes fvr and dac current ? 180 ? ? ? a 3.0 ? 190 ? ? ? a 5.0 30.3 dc characteristics: pic16f/lf1946/47-i/e (power-down) (continued) pic16lf1946/47 standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended pic16f1946/47 standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +85c for industrial -40c ? t a ? +125c for extended param no. device characteristics min. typ? max. +85c max. +125c units conditions v dd note * these parameters are char acterized but not tested. ? data in ?typ? column is at 3.0v, 25c unless otherwise stated. these parameters are for design guidance only and are not tested. note 1: the peripheral current is the sum of the base i dd or i pd and the additional current consumed when this peripheral is enabled. the peripheral ? current can be determined by subtracting the base i dd or i pd current from this limit. max values should be used when calculating total current consumption. 2: 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 high-impedance state and tied to v dd . 3: a/d oscillator source is f rc . 4: 0.1 ? f capacitor on v cap (rf0).
pic16(l)f1946/1947 ds41414c-page 400 preliminary ? 2010-2011 microchip technology inc. 30.4 dc characteristics: pic16f/lf1946/47-i/e 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 v il input low voltage i/o port: d032 with ttl buffer ? ? 0.8 v 4.5v ? v dd ? 5.5v d032a ? ? 0.15 v dd v1.8v ? v dd ? 4.5v d033 with schmitt trigger buffer ? ? 0.2 v dd v2.0v ? v dd ? 5.5v with i 2 c? levels ? ? 0.3 v dd v with smbus levels ? ? 0.8 v 2.7v ? v dd ? 5.5v d034 mclr , osc1 (rc mode) (1) ??0.2v dd v d034a osc1 (hs mode) ? ? 0.3 v dd v v il input low voltage i/o port: d032 with ttl buffer ? ? 0.8 v 4.5v ? v dd ? 5.5v d032a ? ? 0.15 v dd v1.8v ? v dd ? 4.5v v ih input high voltage i/o ports: d040 with ttl buffer 2.0 ? ? v 4.5v ? v dd ?? 5.5v d040a 0.25 v dd + 0.8 ??v1.8v ? v dd ? 4.5v d041 with schmitt trigger buffer 0.8 v dd ??v2.0v ? v dd ? 5.5v with i 2 c? levels 0.7 v dd ??v with smbus levels 2.1 ? ? v 2.7v ? v dd ? 5.5v d042 mclr 0.8 v dd ??v d043a osc1 (hs mode) 0.7 v dd ??v d043b osc1 (rc mode) 0.9 v dd ??v ( note 1 ) v dd ? 2.0v i il input leakage current (2) d060 i/o ports ? 5 5 125 1000 na na v ss ? v pin ? v dd , pin at high- impedance @ 85c 125c d061 mclr (3) ? 50 200nav ss ? v pin ? v dd @ 85c i pur weak pull-up current d070* 25 25 100 140 200 300 ? a v dd = 3.3v, v pin = v ss v dd = 5.0v, v pin = v ss v ol output low voltage (4) d080 i/o ports ??0.6v i ol = 8ma, v dd = 5v i ol = 6ma, v dd = 3.3v i ol = 1.8ma, v dd = 1.8v v oh output high voltage (4) d090 i/o ports v dd - 0.7 ? ? v i oh = 3.5ma, v dd = 5v i oh = 3ma, v dd = 3.3v i oh = 1ma, v dd = 1.8v legend: tbd = to be determined * these parameters are characterized but not tested. ? data in ?typ? column is at 3.0v, 25c unless otherwise stated. these parameters are for design guidance only and are not tested. note 1: in rc oscillator configuration, the osc1/clkin pin is a schm itt trigger input. it is not recommended to use an external clock in rc mode. 2: negative current is defined as current sourced by the pin. 3: the leakage current on the mclr pin is strongly dependent on the applied voltage level. the specified levels represent normal operating conditions. higher leakage current may be measured at different input voltages. 4: including osc2 in clkout mode.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 401 pic16(l)f1946/1947 capacitive loading specs on output pins d101* cosc2 osc2 pin ? ? 15 pf in xt, hs and lp modes when external clock is used to drive osc1 d101a* c io all i/o pins ? ? 50 pf v cap capacitor charging d102 charging current ? 200 ? ? a d102a source/sink capability when charging complete ?0.0?ma 30.4 dc characteristics: pic16f/lf1946/47-i/e (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. sym. characteristic min. typ? max. units conditions legend: tbd = to be determined * these parameters are char acterized but not tested. ? data in ?typ? column is at 3.0v, 25c unless otherwise stated. these parameters are for design guidance only and are not tested. note 1: in rc oscillator configuration, the osc1/clkin pin is a schm itt trigger input. it is not recommended to use an external clock in rc mode. 2: negative current is defined as current sourced by the pin. 3: the leakage current on the mclr pin is strongly dependent on the applied voltage level. the specified levels represent normal operating conditions. higher leakage current may be measured at different input voltages. 4: including osc2 in clkout mode.
pic16(l)f1946/1947 ds41414c-page 402 preliminary ? 2010-2011 microchip technology inc. 30.5 memory programming requirements dc characteristics standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +125c param no. sym. characteristic min. typ? max. units conditions program memory programming specifications d110 v ihh voltage on mclr /v pp /re3 pin 8.0 ? 9.0 v ( note 3, note 4 ) d111 i ddp supply current during programming ??10ma d112 v dd for bulk erase 2.7 ? v dd max. v d113 v pew v dd for write or row erase v dd min. ?v dd max. v d114 i pppgm current on mclr /v pp during erase/ write ??1.0ma d115 i ddpgm current on v dd during erase/write ? 5.0 ma data eeprom memory d116 e d byte endurance 100k ? ?e/w-40 ? c to +85 ? c d117 v drw v dd for read/write v dd min. ?v dd max. v d118 t dew erase/write cycle time ? 4.0 5.0 ms d119 t retd characteristic retention ? 40 ? year -40c to +55c provided no other specifications are violated d120 t ref number of total erase/write cycles before refresh (2) 1m 10m ? e/w -40c to +85c program flash memory d121 e p cell endurance 10k ? ?e/w-40 ? c to +85 ? c ( note 1 ) d122 v pr v dd for read v dd min. ?v dd max. v d123 t iw self-timed write cycle time ? 2 2.5 ms d124 t retd characteristic retention ? 40 ? year provided no other specifications are violated ? data in ?typ? column is at 3.0v, 25c unless otherwise stated. these parameters are for design guidance only and are not tested. note 1: self-write and block erase. 2: refer to section 11.2 ?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 icd 2 v pp voltage must be placed between the icd 2 and target system when programming or debugging with the icd 2.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 403 pic16(l)f1946/1947 30.6 thermal considerations standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +125c param no. sym. characteristic typ. units conditions th01 ? ja thermal resistance junction to ambient 48.3 ? c/w 64-pin tqfp package 28 ? c/w 64-pin qfn package th02 ? jc thermal resistance junction to case 26.1 ? c/w 64-pin tqfp package 0.24 ? c/w 64-pin qfn package th03 t jmax maximum junction temperature 150 ? c th04 pd power dissipation ? w pd = p internal + p i / o th05 p internal internal power dissipation ? w p internal = i dd x v dd (1) th06 p i / o i/o power dissipation ? w p i / o = ? (i ol * v ol ) + ? (i oh * (v dd - v oh )) th07 p der derated power ? w p der = pd max (t j - t a )/ ? ja (2) note 1: i dd is current to run the chip alone without driving any load on the output pins. 2: t a = ambient temperature 3: t j = junction temperature
pic16(l)f1946/1947 ds41414c-page 404 preliminary ? 2010-2011 microchip technology inc. 30.7 timing parameter symbology the timing parameter symbols have been created with one of the following formats: figure 30-5: load conditions 1. tpps2pps 2. tpps t f frequency t time lowercase letters (pp) and their meanings: pp cc ccp1 osc osc1 ck clkout 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 ffall pperiod hhigh rrise i invalid (high-impedance) v valid l low z high-impedance v ss c l legend: c l = 50 pf for all pins, 15 pf for osc2 output load condition pin
? 2010-2011 microchip technology inc. preliminary ds41414c-page 405 pic16(l)f1946/1947 30.8 ac characteristics: pic16f/lf1946/47-i/e figure 30-6: clock timing table 30-1: clock oscillator timing requirements standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +125c param no. sym. characteristic min. typ? max. units conditions os01 f osc external clkin frequency (1) dc ? 0.5 mhz ec oscillator mode (low) dc ? 4 mhz ec oscillator mode (medium) dc ? 20 mhz ec oscillator mode (high) oscillator frequency (1) ? 32.768 ? khz lp oscillator mode 0.1 ? 4 mhz xt oscillator mode 1 ? 4 mhz hs oscillator mode 1 ? 20 mhz hs oscillator mode, v dd > 2.7v dc ? 4 mhz rc oscillator mode, v dd > 2.0v os02 t osc external clkin period (1) 27 ? ?? s lp oscillator mode 250 ? ? ns xt oscillator mode 50 ? ? ns hs oscillator mode 50 ? ? ns ec oscillator mode oscillator period (1) ? 30.5 ? ? s lp oscillator mode 250 ? 10,000 ns xt oscillator mode 50 ? 1,000 ns hs oscillator mode 250 ? ? ns rc oscillator mode os03 t cy instruction cycle time (1) 200 t cy dc ns t cy = 4/f osc os04* tosh, to sl external clkin high, external clkin low 2?? ? s lp oscillator 100 ? ? ns xt oscillator 20 ? ? ns hs oscillator os05* tosr, to sf external clkin rise, external clkin fall 0? ? ns lp oscillator 0? ? ns xt oscillator 0? ? ns hs oscillator * these parameters are characterized but not tested. ? data in ?typ? column is at 3.0v, 25c unless otherwise stat ed. these parameters are for design guidance only and are not tested. note 1: instruction cycle period (t cy ) equals four times the input oscillator time base period. 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 high er than expected current con- sumption. all devices are tested to operate at ?min? values with an external clock applied to osc1 pin. when an external clock input is used, the ?max? cycle time limit is ?dc? (no clock) for all devices. osc1/clkin osc2/clkout q4 q1 q2 q3 q4 q1 os02 os03 os04 os04 osc2/clkout (lp,xt,hs modes) (clkout mode)
pic16(l)f1946/1947 ds41414c-page 406 preliminary ? 2010-2011 microchip technology inc. table 30-2: oscillator parameters table 30-3: pll clock timing specifications (v dd = 2.7v to 5.5v) standard operating conditions (unless otherwise stated) operating temperature -40c ?? t a ?? +125c param no. sym. characteristic freq. tolerance min. typ? max. units conditions os08 hf osc internal calibrated hfintosc frequency (2) ? 2% ? 16.0 ? mhz 0c ? t a ? +60c, v dd ? 2.5v ? 3% ? 16.0 ? mhz 60c ? t a ? +85c, v dd ? 2.5v ? 5% ? 16.0 ? mhz -40c ? t a ? +125c os08a mf osc internal calibrated mfintosc frequency (2) ? 2% ? 500 ? khz 0c ? t a ? +60c, v dd ? 2.5v ? 3% ? 500 ? khz 60c ? t a ? +85c, v dd ? 2.5v ? 5% ? 500 ? khz -40c ? t a ? +125c os09 lf osc internal lfintosc frequency ? ? 31 ? khz -40c ? t a ? +125c os10* t iosc st hfintosc wake-up from sleep start-up time mfintosc wake-up from sleep start-up time ??3.28 ? s ? ? 24 35 ? s * these parameters are characterized but not tested. ? data in ?typ? column is at 3.0v, 25c unless otherwise stated. these parameters are for design guidance only and are not tested. note 1: instruction cycle period (t cy ) equals four times the input oscillator time bas e period. all specified values are based on characterization data for that particular oscillator ty pe under standard operating conditions with the device executing code. exceeding these specified limits may result in an unst able oscillator operation and/or higher than expected current consumption. all devices are tested to operate at ?min? valu es with an external clock applied to the osc1 pin. when an external clock input is used, the ?max? cycle ti me limit is ?dc? (no clock) for all devices. 2: to ensure these oscillator frequency tolerances, v dd and v ss must be capacitively decoupled as close to the device as possible. 0.1 ? f and 0.01 ? f values in parallel are recommended. 3: by design. param no. sym. characteristic min. typ? max. units conditions f10 f osc oscillator frequency range 4 ? 8 mhz f11 f sys on-chip vco system frequency 16 ? 32 mhz f12 t rc pll start-up time (lock time) ? ? 2 ms f13* ? clk clkout stability (jitter) -0.25% ? +0.25% % * these parameters are characterized but not tested. ? data in ?typ? column is at 5v, 25 ? c unless otherwise stated. these parameters are for design guidance only and are not tested.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 407 pic16(l)f1946/1947 figure 30-7: clkout and i/o timing f osc clkout i/o pin (input) i/o pin (output) q4 q1 q2 q3 os11 os19 os13 os15 os18, os19 os20 os21 os17 os16 os14 os12 os18 old value new value write fetch read execute cycle
pic16(l)f1946/1947 ds41414c-page 408 preliminary ? 2010-2011 microchip technology inc. table 30-4: clkout and i/o timing parameters figure 30-8: reset, watchdog timer, os cillator start-up timer and power-up timer timing standard operating conditions (unless otherwise stated) operating temperature -40c ?? t a ?? +125c param no. sym. characteristic min. typ? max. units conditions os11 tosh2ckl f osc ? to clkout ? (1) ??70nsv dd = 3.3-5.0v os12 tosh2ckh f osc ? to clkout ? (1) ??72nsv dd = 3.3-5.0v os13 tckl2iov clkout ? to port out valid (1) ??20ns os14 tiov2ckh port input valid before clkout ? (1) t osc + 200 ns ? ? ns os15 tosh2iov fosc ? (q1 cycle) to port out valid ? 50 70* ns v dd = 3.3-5.0v os16 tosh2ioi fosc ? (q2 cycle) to port input invalid (i/o in hold time) 50 ? ? ns v dd = 3.3-5.0v os17 tiov2osh port input valid to fosc ?? (q2 cycle) (i/o in setup time) 20 ? ? ns os18 tior port output rise time ? ? 40 15 72 32 ns v dd = 1.8v v dd = 3.3-5.0v os19 tiof port output fall time ? ? 28 15 55 30 ns v dd = 1.8v v dd = 3.3-5.0v os20* tinp int pin input high or low time 25 ? ? ns os21* tioc interrupt-on-change new input level time 25 ? ? ns * these parameters are characterized but not tested. ? data in ?typ? column is at 3.0v, 25 ? c unless otherwise stated. note 1: measurements are taken in rc mode where clkout output is 4 x t osc . v dd mclr internal por pwrt time-out osc start-up time internal reset (1) watchdog timer 33 32 30 31 34 i/o pins 34 note 1: asserted low. reset (1)
? 2010-2011 microchip technology inc. preliminary ds41414c-page 409 pic16(l)f1946/1947 figure 30-9: brown-out rese t timing and characteristics v bor v dd (device in brown-out reset) (device not in brown-out reset) 33 (1) note 1: 64 ms delay only if pwrte bit in the configuration word register is programmed to ? 0 ?. 2 ms delay if pwrte = 0 and vregen = 1 . reset (due to bor) v bor and v hyst 37
pic16(l)f1946/1947 ds41414c-page 410 preliminary ? 2010-2011 microchip technology inc. table 30-5: reset, watchdog timer, oscill ator start-up timer, power-up timer and brown-out reset parameters figure 30-10: timer0 and time r1 external clock timings standard operating conditions (unless otherwise stated) operating temperature -40c ?? t a ?? +125c param no. sym. characteristic min. typ? max. units conditions 30 t mc lmclr pulse width (low) 2 ? ? ? s 31 t wdtlp watchdog timer time-out period 10 16 27 ms v dd = 3.3v-5v, 1:16 prescaler used 32 t ost oscillator start-up timer period (1), (2) ? 1024 ? tosc ( note 3 ) 33* t pwrt power-up timer period, pwrte = 0 40 65 140 ms 34* t ioz i/o high-impedance from mclr low or watchdog timer reset ??2.0 ? s 35 v bor brown-out reset voltage 2.38 1.80 2.5 1.9 2.73 2.11 vborv=2.5v borv=1.9v 36* v hyst brown-out reset hysteresis 0 25 50 mv -40c to +85c 37* t bordc brown-out reset dc response time 1335 ? sv dd ? v bor * these parameters are characterized but not tested. ? data in ?typ? column is at 3.0v, 25c unless otherwise stated. these parameters are for design guidance only and are not tested. note 1: instruction cycle period (t cy ) equals four times the input oscillator time base period. 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 consumption. all devices ar e tested to operate at ?min? values with an external clock applied to the osc1 pin. when an external clock input is used, the ?max? cycle time limit is ?dc? (no clock) for all devices. 2: by design. 3: period of the slower clock. 4: to ensure these voltage tolerances, v dd and v ss must be capacitively decoupled as close to the device as possible. 0.1 ? f and 0.01 ? f values in parallel are recommended. t0cki t1cki 40 41 42 45 46 47 49 tmr0 or tmr1
? 2010-2011 microchip technology inc. preliminary ds41414c-page 411 pic16(l)f1946/1947 table 30-6: timer0 and timer1 external clock requirements figure 30-11: capture/com pare/pwm timings (ccp) table 30-7: capture/compare/pwm requirements (ccp) standard operating conditions (unless otherwise stated) operating temperature -40c ?? t a ?? +125c param no. sym. characteristic min. typ? 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 greater of: 20 or t cy + 40 n ? ? ns n = prescale value (2, 4, ..., 256) 45* t t 1h t1cki high time synchronous, no prescaler 0.5 t cy + 20 ? ? ns synchronous, with prescaler 15 ? ? ns asynchronous 30 ? ? ns 46* t t 1l t1cki low time synchronous, no prescaler 0.5 t cy + 20 ? ? ns synchronous, with prescaler 15 ? ? ns asynchronous 30 ? ? ns 47* t t 1p t1cki input period synchronous greater of: 30 or t cy + 40 n ? ? ns n = prescale value (1, 2, 4, 8) asynchronous 60 ? ? ns 48 f t 1 timer1 oscillator input frequency range (oscillator enabled by setting bit t1oscen) 32.4 32.768 33.1 khz 49* tckez tmr 1 delay from external clock edge to timer increment 2 t osc ?7 t osc ? timers in sync mode * these parameters are characterized but not tested. ? data in ?typ? column is at 3.0v, 25c unless otherwise stated. these parameters are for design guidance only and are not tested. standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +125c param no. sym. characteristic min. typ? max. units conditions cc01* tccl ccpx input low time no prescaler 0.5t cy + 20 ? ? ns with prescaler 20 ? ? ns cc02* tcch ccpx input high time no prescaler 0.5t cy + 20 ? ? ns with prescaler 20 ? ? ns cc03* tccp ccpx input period 3t cy + 40 n ? ? ns n = prescale value (1, 4 or 16) * these parameters are characterized but not tested. ? data in ?typ? column is at 3.0v, 25c unless otherwise stated. these parameters are fo r design guidance only and are not tested. note: refer to figure 30-5 for load conditions. (capture mode) cc01 cc02 cc03 ccpx
pic16(l)f1946/1947 ds41414c-page 412 preliminary ? 2010-2011 microchip technology inc. table 30-8: pic16f/lf1946/47 a/ d converter (adc) characteristics : table 30-9: pic16f/lf1946/47 a/d conversion requirements standard operating conditions (unless otherwise stated) operating temperature t a ?? 25c param no. sym. characteristic min. typ? max. units conditions ad01 n r resolution ? ? 10 bit ad02 e il integral error ? ? 1.7 lsb v ref = 3.0v ad03 e dl differential error ? ? 1 lsb no missing codes v ref = 3.0v ad04 e off offset error ? ? 2.5 lsb v ref = 3.0v ad05 e gn gain error ? ? 2.0 lsb v ref = 3.0v ad06 v ref reference voltage (3) 1.8 ? v dd vv ref = (v ref + minus v ref -) ( note 5 ) ad07 v ain full-scale range v ss ?v ref v ad08 z ain recommended impedance of analog voltage source ?? 10k ? can go higher if external 0.01 ? f capacitor is present on input pin. * these parameters are characterized but not tested. ? data in ?typ? column is at 3.0v, 25c unless otherwise stat ed. these parameters are for design guidance only and are not tested. note 1: total absolute error includes integral, differential, offset and gain errors. 2: the a/d conversion result never dec reases with an increase in the input voltage and has no missing codes. 3: adc v ref is from external v ref , v dd pin or fvr, whichever is selected as reference input. 4: when adc is off, it will not consume any current other than leakage current. the power-down current specification includes any such leakage from the adc module. 5: fvr voltage selected must be 2.048v or 4.096v. standard operating conditions (unless otherwise stated) operating temperature -40c ? t a ? +125c param no. sym. characteristic min. typ? max. units conditions ad130* t ad a/d clock period 1.0 ? 9.0 ? st osc -based a/d internal rc oscillator period 1.0 2.5 6.0 ? s adcs<1:0> = 11 (adrc mode) ad131 t cnv conversion time (not including acquisition time) (1) ?11?t ad set go/done bit to conversion complete ad132* t acq acquisition time ? 5.0 ? ? s * these parameters are characterized but not tested. ? data in ?typ? column is at 3.0v, 25c unless otherwise stated. these parameters are for design guidance only and are not tested. note 1: the adres register may be read on the following t cy cycle.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 413 pic16(l)f1946/1947 figure 30-12: pic16f/lf1946/47 a/d conversion timing (normal mode) figure 30-13: pic16f/lf1946/47 a/d conversion timing (sleep mode) ad131 ad130 bsf adcon0, go q4 a/d clk a/d data adres adif go sample old_data sampling stopped done new_data 765 3210 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. 1 t cy 4 ad134 (t osc /2 (1) ) 1 t cy ad132 ad132 ad131 ad130 bsf adcon0, go q4 a/d clk a/d data adres adif go sample old_data sampling stopped done new_data 7 5 3210 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. ad134 4 6 1 t cy (t osc /2 + t cy (1) ) 1 t cy
pic16(l)f1946/1947 ds41414c-page 414 preliminary ? 2010-2011 microchip technology inc. table 30-10: comparator specifications table 30-11: digital-to-analog conv erter (dac) specifications figure 30-14: usart synchronous transmission (master/slave) timing operating conditions: 1.8v < v dd < 5.5v, -40c < t a < +125c (unless otherwise stated). param no. sym. characteristics min. typ. max. units comments cm01 v ioff input offset voltage (3) ? 7.5 60 mv high-power mode cm02 v icm input common mode voltage 0 ? v dd v cm03 cmrr common mode rejection ratio ? 50 ? db cm04 t resp response time ? 150 400 ns ( note 1 ) cm04a t resp response time rising edge ? 400 800 ns high-power mode cm04b response time falling edge ? 200 400 ns high-power mode cm04c response time rising edge ? 1200 ? ns low-power mode cm04d response time falling edge ? 550 ? ns low-power mode cm05 t mc 2 ov comparator mode change to output valid* ?? 10 ? s cm06 c hyster comparator hysteresis ? 45 ? mv ( note 2 ) * these parameters are characterized but not tested. note 1: response time measured with one comparator input at v dd /2, while the other input transitions from v ss to v dd . 2: comparator hysteresis is available when the cxhys bit of the cmxcon0 register is enabled. 3: high power only. operating conditions: 2.5v < v dd < 5.5v, -40c < t a < +85c (unless otherwise stated). param no. sym. characteristics min. typ. max. units comments dac01* c lsb step size ? v dd /32 ? v dac02* c acc absolute accuracy ? ? ? 1/2 lsb dac03* c r unit resistor value (r) ? 5k ? ? dac04* c st settling time (1) ??10 ? s * these parameters are characterized but not tested. legend: tbd = to be determined note 1: settling time measured while dacr<4:0> transitions from ? 0000 ? to ? 1111 ?. note: refer to figure 30-5 for load conditions. us121 us121 us120 us122 ck dt
? 2010-2011 microchip technology inc. preliminary ds41414c-page 415 pic16(l)f1946/1947 table 30-12: usart synchronous tran smission requirements figure 30-15: usart synchrono us receive (master/slave) timing table 30-13: usart synchronous rece ive requirements standard operating conditions (unless otherwise stated) operating temperature -40c ?? t a ?? +125c param. no. symbol characteristic min. max. units conditions us120 t ck h2 dt v sync xmit (m aster and s lave ) clock high to data-out valid 3.0-5.5v ? 80 ns 1.8-5.5v ? 100 ns us121 t ckrf clock out rise time and fall time (master mode) 3.0-5.5v ? 45 ns 1.8-5.5v ? 50 ns us122 t dtrf data-out rise time and fall time 3.0-5.5v ? 45 ns 1.8-5.5v ? 50 ns standard operating conditions (unless otherwise stated) operating temperature -40c ?? t a ?? +125c param. no. symbol characteristic min. max. units conditions us125 t dt v2 ckl sync rcv (m aster and s lave ) data-hold before ck ? (dt hold time) 10 ? ns us126 t ck l2 dtl data-hold after ck ? (dt hold time) 15 ? ns note: refer to figure 30-5 for load conditions. us125 us126 ck dt
pic16(l)f1946/1947 ds41414c-page 416 preliminary ? 2010-2011 microchip technology inc. figure 30-16: spi master mode timing (cke = 0 , smp = 0 ) figure 30-17: spi master mode timing (cke = 1 , smp = 1 ) ss sck (ckp = 0 ) sck (ckp = 1 ) sdo sdi sp70 sp71 sp72 sp73 sp74 sp75, sp76 sp78 sp79 sp80 sp79 sp78 msb lsb bit 6 - - - - - -1 msb in lsb in bit 6 - - - -1 note: refer to figure 30-5 for load conditions. ss sck (ckp = 0 ) sck (ckp = 1 ) sdo sdi sp81 sp71 sp72 sp74 sp75, sp76 sp78 sp80 msb sp79 sp73 msb in bit 6 - - - - - -1 lsb in bit 6 - - - -1 lsb note: refer to figure 30-5 for load conditions.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 417 pic16(l)f1946/1947 figure 30-18: spi slav e mode timing (cke = 0 ) figure 30-19: spi slav e mode timing (cke = 1 ) ss sck (ckp = 0 ) sck (ckp = 1 ) sdo sdi sp70 sp71 sp72 sp73 sp74 sp75, sp76 sp77 sp78 sp79 sp80 sp79 sp78 msb lsb bit 6 - - - - - -1 msb in bit 6 - - - -1 lsb in sp83 note: refer to figure 30-5 for load conditions. ss sck (ckp = 0 ) sck (ckp = 1 ) sdo sdi sp70 sp71 sp72 sp82 sp74 sp75, sp76 msb bit 6 - - - - - -1 lsb sp77 msb in bit 6 - - - -1 lsb in sp80 sp83 note: refer to figure 30-5 for load conditions.
pic16(l)f1946/1947 ds41414c-page 418 preliminary ? 2010-2011 microchip technology inc. table 30-14: spi mode requirements figure 30-20: i 2 c? bus start/stop bits timing param no. symbol characteristic min. typ? max. units conditions sp70* t ss l2 sc h, t ss l2 sc l ss ? to sck ? or sck ? input t cy ??ns sp71* t sc h sck input high time (slave mode) t cy + 20 ? ? ns sp72* t sc l sck input low time (slave mode) t cy + 20 ? ? ns sp73* t di v2 sc h, t di v2 sc l setup time of sdi data input to sck edge 100 ? ? ns sp74* t sc h2 di l, t sc l2 di l hold time of sdi data input to sck edge 100 ? ? ns sp75* t do r sdo data output rise time 3.0-5.5v ? 10 25 ns 1.8-5.5v ? 25 50 ns sp76* t do f sdo data output fall time ? 10 25 ns sp77* t ss h2 do zss ? to sdo output high-impedance 10 ? 50 ns sp78* t sc r sck output rise time (master mode) 3.0-5.5v ? 10 25 ns 1.8-5.5v ? 25 50 ns sp79* t sc f sck output fall time (master mode) ? 10 25 ns sp80* t sc h2 do v, t sc l2 do v sdo data output valid after sck edge 3.0-5.5v ? ? 50 ns 1.8-5.5v ? ? 145 ns sp81* t do v2 sc h, t do v2 sc l sdo data output setup to sck edge tcy ? ? ns sp82* t ss l2 do v sdo data output valid after ss ? edge ? ? 50 ns sp83* t sc h2 ss h, t sc l2 ss h ss ?? after sck edge 1.5t cy + 40 ? ? ns * these parameters are characterized but not tested. ? data in ?typ? column is at 3.0v, 25c unless otherwise stated. these parameters are for design guidance only and are not tested. note : refer to figure 30-5 for load conditions. sp91 sp92 sp93 scl sda start condition stop condition sp90
? 2010-2011 microchip technology inc. preliminary ds41414c-page 419 pic16(l)f1946/1947 table 30-15: i 2 c? bus start/stop bits requirements figure 30-21: i 2 c? bus data timing param no. symbol characteristic min. typ max. units conditions sp90* t su : sta start condition 100 khz mode 4700 ? ? ns only relevant for repeated start condition setup time 400 khz mode 600 ? ? sp91* 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 ? ? sp92* t su : sto stop condition 100 khz mode 4700 ? ? ns setup time 400 khz mode 600 ? ? sp93 t hd : sto stop condition 100 khz mode 4000 ? ? ns hold time 400 khz mode 600 ? ? * these parameters are characterized but not tested. note: refer to figure 30-5 for load conditions. sp90 sp91 sp92 sp100 sp101 sp103 sp106 sp107 sp109 sp109 sp110 sp102 scl sda in sda out
pic16(l)f1946/1947 ds41414c-page 420 preliminary ? 2010-2011 microchip technology inc. table 30-16: i 2 c? bus data requirements param. no. symbol characteristic min. max. units conditions sp100* t high clock high time 100 khz mode 4.0 ? ? s device must operate at a minimum of 1.5 mhz 400 khz mode 0.6 ? ? s device must operate at a minimum of 10 mhz ssp module 1.5t cy ? sp101* t low clock low time 100 khz mode 4.7 ? ? s device must operate at a minimum of 1.5 mhz 400 khz mode 1.3 ? ? s device must operate at a minimum of 10 mhz ssp module 1.5t cy ? sp102* t r sda and scl rise time 100 khz mode ? 1000 ns 400 khz mode 20 + 0.1c b 300 ns c b is specified to be from 10-400 pf sp103* t f sda and scl fall time 100 khz mode ? 250 ns 400 khz mode 20 + 0.1c b 250 ns c b is specified to be from 10-400 pf sp106* t hd : dat data input hold time 100 khz mode 0 ? ns 400 khz mode 0 0.9 ? s sp107* t su : dat data input setup time 100 khz mode 250 ? ns ( note 2 ) 400 khz mode 100 ? ns sp109* t aa output valid from clock 100 khz mode ? 3500 ns ( note 1 ) 400 khz mode ? ? ns sp110* 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 sp111 c b bus capacitive loading ? 400 pf * these parameters are characterized but not tested. note 1: as a transmitter, the device must provide this internal minimum delay time to bridge the undefined region (min. 300 ns) of the falling edge of scl to avoid unintended generation of start or stop conditions. 2: a fast mode (400 khz) i 2 c ? bus device can be used in a standard mode (100 khz) 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 scl signal. if such a device does stretch the low period of the scl signal, it must output the next data bit to the sda line t r max. + t su : dat = 1000 + 250 = 1250 ns (according to the standard mode i 2 c bus specification), before the scl line is released.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 421 pic16(l)f1946/1947 table 30-17: cap sense os cillator specifications figure 30-22: cap sense oscillator param. no. symbol characteristic min. typ? max. units conditions cs01* i src current source high ? -8 ? ? a medium ? -1.5 ? ? a low ? -0.3 ? ? a cs02* i snk current sink high ? 7.5 ? ? a medium ? 1.5 ? ? a low ? 0.25 ? ? a cs03* vc th cap threshold ? 0.8 ? mv cs04* vc tl cap threshold ? 0.4 ? mv cs05* vc hyst cap hysteresis (v cth -v ctl ) high medium low ? ? ? 525 375 300 ? ? ? mv mv mv * these parameters are characterized but not tested. ? data in ?typ? column is at 3.0v, 25c unless otherwise stated. these parameters are for design guidance only and are not tested. i src vc th vc tl i snk enabled enabled
pic16(l)f1946/1947 ds41414c-page 422 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 423 pic16(l)f1946/1947 31.0 dc and ac characteristics graphs and charts graphs and charts are not available at this time.
pic16(l)f1946/1947 ds41414c-page 424 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 425 pic16(l)f1946/1947 32.0 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 32.1 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.
pic16(l)f1946/1947 ds41414c-page 426 preliminary ? 2010-2011 microchip technology inc. 32.2 mplab c compilers for various device families the mplab c compiler code development systems are complete ansi c compilers for microchip?s 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. 32.3 hi-tech c for various device families the hi-tech c compiler code development systems are complete ansi c compilers for microchip?s 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. 32.4 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 32.5 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 32.6 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
? 2010-2011 microchip technology inc. preliminary ds41414c-page 427 pic16(l)f1946/1947 32.7 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. 32.8 mplab real ice in-circuit emulator system mplab real ice in-circuit emulator system is microchip?s 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 engineer?s 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. 32.9 mplab icd 3 in-circuit debugger system mplab icd 3 in-circuit debugger system is micro- chip's 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 engineer's 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. 32.10 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 engineer's 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 user?s guide, lessons, tutorial, compiler and mplab ide software.
pic16(l)f1946/1947 ds41414c-page 428 preliminary ? 2010-2011 microchip technology inc. 32.11 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 microchip?s 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 microchip?s 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 user?s guide, lessons, tutorial, compiler and mplab ide software. 32.12 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. 32.13 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.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 429 pic16(l)f1946/1947 33.0 packaging information 33.1 package marking information * standard picmicro ? device marking consists of microchip part number, year code, week code and traceability code. for picmicro device marking beyond this, certain price adders apply. please check with your microchip sales office. for qtp devices, any special marking adders are included in qtp price. 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 64-lead tqfp (10x10x1mm) xxxxxxxxxx xxxxxxxxxx xxxxxxxxxx yywwnnn example pic16f1946 -i/pt 0610017 64-lead qfn (9x9x1mm) xxxxxxxxxxx xxxxxxxxxxx xxxxxxxxxxx yywwnnn example pic16f1947 -i/pt 0610017
pic16(l)f1946/1947 ds41414c-page 430 preliminary ? 2010-2011 microchip technology inc. 33.2 package details the following sections give the technical details of the packages. note: for the most current package drawings, please see the microchip packaging specification located at http://www.microchip.com/packaging
? 2010-2011 microchip technology inc. preliminary ds41414c-page 431 pic16(l)f1946/1947 note: for the most current package drawings, please see the microchip packaging specification located at http://www.microchip.com/packaging
pic16(l)f1946/1947 ds41414c-page 432 preliminary ? 2010-2011 microchip technology inc.

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pic16(l)f1946/1947 ds41414c-page 434 preliminary ? 2010-2011 microchip technology inc. notes:
? 2010-2011 microchip technology inc. preliminary ds41414c-page 435 pic16(l)f1946/1947 appendix a: data sheet revision history revision a (3/2010) original release. revision b (9/2010) updated with current electrical specifications; added temperature indicator module section; other minor corrections. revision c (5/2011) updated the eusart section; updated the electrical specifications section; updated table 3-8, figure 13-1 and equation 16-1. appendix b: migrating from other pic ? devices this shows a comparison of features in the migration from the pic16f917 device to the pic16f1946 family of devices. b.1 pic16f946 to pic16f1946 table b-1: feature comparison feature pic16f917 pic16f1946 max. operating speed 20 mhz 32 mhz max. program memory (words) 8k 8k max. sram (bytes) 368 512 a/d resolution 10-bit 10-bit timers (8/16-bit) 2/1 4/1 oscillator modes 4 8 brown-out reset y y internal pull-ups rb<7:0> rb<7:0> interrupt-on-change rb<7:4> rb<7:0> comparator 2 2 ausart/eusart 1/0 0/2 extended wdt y y software control option of wdt/bor ny intosc frequencies 30 khz - 8mhz 31 khz - 16 mhz clock switching y y capacitive sensing n y ccp/eccp 2/0 2/3 enhanced pic16 cpu n y mssp/ssp 0/1 2/0 lcd y y note: this device has been designed to perform to the parameters of its data sheet. it has been tested to an electrical specification designed to determine its conformance with these parameters. due to process dif- ferences in the manufacture of this device, this device may have different perfor- mance characteristics than its earlier ver- sion. these differences may cause this device to perform differently in your appli- cation than the earlier version of this device.
pic16(l)f1946/1947 ds41414c-page 436 preliminary ? 2010-2011 microchip technology inc. note: the user should verify that the device oscillator starts and performs as expected. adjusting the loading capacitor values and/or the oscillator mode may be required.
? 2010-2011 microchip technology inc. preliminary ds41414c-page 437 pic16(l)f1946/1947 index a a/d specifications............................................................ 412 absolute maximum ratings (pic16f/lf1946/47) ............ 389 ac characteristics industrial and extended ............................................ 405 load conditions ........................................................ 404 ackstat ......................................................................... 278 ackstat status flag ...................................................... 278 adc .................................................................................. 159 acquisition requirements ......................................... 170 associated registers.................................................. 172 block diagram........................................................... 160 calculating acquisition time..................................... 170 channel selection..................................................... 161 configuration............................................................. 161 configuring interrupt ................................................. 165 conversion clock...................................................... 161 conversion procedure .............................................. 165 internal sampling switch (r ss ) impedance.............. 170 interrupts................................................................... 163 operation .................................................................. 164 operation during sleep ............................................ 164 port configuration ..................................................... 161 reference voltage (v ref )......................................... 161 source impedance.................................................... 170 special event trigger................................................ 164 starting an a/d conversion ...................................... 163 adcon0 register....................................................... 34, 166 adcon1 register....................................................... 34, 167 addfsr ........................................................................... 379 addwfc .......................................................................... 379 adresh register............................................................... 34 adresh register (adfm = 0) ......................................... 168 adresh register (adfm = 1) ......................................... 169 adresl register (adfm = 0).......................................... 168 adresl register (adfm = 1).......................................... 169 alternate pin function....................................................... 125 analog-to-digital converter. see adc ansela register ............................................................. 129 ansele register ............................................................. 141 anself register.............................................................. 145 apfcon register............................................................. 126 assembler mpasm assembler................................................... 426 automatic context saving................................................... 92 b baudcon register.......................................................... 308 bf ............................................................................. 278, 280 bf status flag .......................................................... 278, 280 block diagram capacitive sensing ........................................... 325, 326 block diagrams (ccp) capture mode operation ............................... 214 adc .......................................................................... 160 adc transfer function ............................................. 171 analog input model ........................................... 171, 182 ccp pwm................................................................. 218 clock source............................................................... 62 comparator ............................................................... 178 compare ................................................................... 216 crystal operation .................................................. 64, 65 digital-to-analog converter (dac) ........................... 174 eusart receive ..................................................... 298 eusart transmit .................................................... 297 external rc mode ...................................................... 65 fail-safe clock monitor (fscm)................................. 73 generic i/o port........................................................ 125 interrupt logic............................................................. 87 lcd bias voltage generation .................................. 343 lcd clock generation.............................................. 342 on-chip reset circuit................................................. 79 peripheral interrupt logic ........................................... 88 pic16f/lf1946/47 ............................................... 12, 20 pwm (enhanced) ..................................................... 222 resonator operation .................................................. 64 timer0 ...................................................................... 193 timer1 ...................................................................... 197 timer1 gate.............................................. 202, 203, 204 timer2/4/6 ................................................................ 209 voltage reference.................................................... 155 voltage reference output buffer example .............. 174 borcon register.............................................................. 81 bra .................................................................................. 380 break character (12-bit) transmit and receive ............... 316 brown-out reset (bor)...................................................... 81 specifications ........................................................... 410 timing and characteristics ....................................... 409 c c compilers mplab c18 .............................................................. 426 call................................................................................. 381 callw ............................................................................. 381 capacitive sensing ........................................................... 325 associated registers w/ capacitive sensing............. 333 specifications ........................................................... 421 capture module. see enhanced capture/compare/ pwm(eccp) capture/compare/pwm ................................................... 213 capture/compare/pwm (ccp) associated registers w/ capture ............................. 215 associated registers w/ compare ........................... 217 associated registers w/ pwm ......................... 221, 235 capture mode ........................................................... 214 ccpx pin configuration............................................ 214 compare mode ......................................................... 216 ccpx pin configuration.................................... 216 software interrupt mode ........................... 214, 216 special event trigger ....................................... 216 timer1 mode resource ............................ 214, 216 prescaler .................................................................. 214 pwm mode duty cycle ........................................................ 219 effects of reset ................................................ 221 example pwm frequencies and resolutions, 20 mhz ................................ 220 example pwm frequencies and resolutions, 32 mhz ................................ 220 example pwm frequencies and resolutions, 8 mhz .................................. 220 operation in sleep mode.................................. 221 resolution ........................................................ 220 system clock frequency changes .................. 221 pwm operation ........................................................ 218 pwm overview ......................................................... 218
pic16(l)f1946/1947 ds41414c-page 438 preliminary ? 2010-2011 microchip technology inc. pwm period .............................................................. 219 pwm setup ............................................................... 219 ccp1con register ...................................................... 38, 39 ccpr1h register ......................................................... 38, 39 ccpr1l register.......................................................... 38, 39 ccptmrs0 register ........................................................ 237 ccptmrs1 register ........................................................ 238 ccpxas register.............................................................. 239 ccpxcon (eccpx) register ........................................... 236 clock accuracy with asynchronous operation ................. 306 clock sources external modes ........................................................... 63 ec ....................................................................... 63 hs ....................................................................... 63 lp........................................................................ 63 ost..................................................................... 64 rc....................................................................... 65 xt ....................................................................... 63 internal modes ............................................................ 66 hfintosc.......................................................... 66 internal oscillator clock switch timing............... 68 lfintosc .......................................................... 67 mfintosc ......................................................... 66 clock switching................................................................... 70 cmout register............................................................... 184 cmxcon0 register .......................................................... 183 cmxcon1 register .......................................................... 184 code examples a/d conversion ......................................................... 165 changing between capture prescalers .................... 214 initializing porta..................................................... 127 initializing portb..................................................... 130 initializing portc..................................................... 133 initializing portd..................................................... 136 initializing porte..................................................... 139 initializing portf ..................................................... 142 initializing portg .................................................... 146 write verify ............................................................... 121 writing to flash program memory ............................ 119 comparator associated registers ................................................ 185 operation .................................................................. 177 comparator module .......................................................... 177 cx output state versus input conditions ................. 179 comparator specifications ................................................ 414 comparators c2out as t1 gate ................................................... 199 compare module. see enhanced capture/compare/ pwm (eccp) config1 register.............................................................. 56 config2 register.............................................................. 58 core registers .................................................................... 33 cpscon0 register .......................................................... 331 cpscon1 register .......................................................... 332 customer change notification service ............................. 445 customer notification service........................................... 445 customer support ............................................................. 445 d daccon0 (digital-to-analog converter control 0) register..................................................................... 176 daccon1 (digital-to-analog converter control 1) register..................................................................... 176 data eeprom memory .................................................... 111 associated registers ................................................ 124 code protection ........................................................ 112 reading .................................................................... 112 writing ...................................................................... 112 data memory ................................................................ 24, 27 dc and ac characteristics............................................... 423 dc characteristics extended and industrial (pic16f/lf1946/47-i/e)..... 400 industrial and extended (pic16f/lf1946/47) .......... 392 development support ....................................................... 425 device configuration .......................................................... 55 code protection .......................................................... 59 configuration word..................................................... 55 user id ................................................................. 59, 60 device overview......................................................... 11, 107 digital-to-analog converter (dac) ................................... 173 associated registers ................................................ 176 effects of a reset ..................................................... 174 specifications ........................................................... 414 e eccp/ccp. see enhanced capture/compare/pwm eeadr registers ............................................................. 111 eeadrh registers........................................................... 111 eeadrl register ............................................................. 122 eeadrl registers ........................................................... 111 eecon1 register..................................................... 111, 123 eecon2 register..................................................... 111, 124 eedath register............................................................. 122 eedatl register ............................................................. 122 eeprom data memory avoiding spurious write ........................................... 112 write verify ............................................................... 121 effects of reset pwm mode ............................................................... 221 electrical specifications (pic16f/lf1946/47) .................. 389 enhanced capture/compare/pwm (eccp)..................... 213 enhanced pwm mode.............................................. 222 auto-restart ..................................................... 231 auto-shutdown.................................................. 230 direction change in full-bridge output mode.. 228 full-bridge application...................................... 226 full-bridge mode .............................................. 226 half-bridge application ..................................... 225 half-bridge application examples .................... 232 half-bridge mode.............................................. 225 output relationships (active-high and active-low)............................................... 223 output relationships diagram.......................... 224 programmable dead band delay..................... 232 shoot-through current...................................... 232 start-up considerations .................................... 234 specifications ........................................................... 411 enhanced mid-range cpu.................................................. 19 enhanced universal synchronous asynchronous receiver transmitter (eusart) .............................. 297 errata .................................................................................... 9 eusart ........................................................................... 297 asynchronous mode ................................................. 299 12-bit break transmit and receive .................. 316 associated registers, receive......................... 305 associated registers, transmit........................ 301 auto-wake-up on break ................................... 314 baud rate generator (brg) ............................ 309 clock accuracy................................................. 306 receiver ........................................................... 302 setting up 9-bit mode with address detect ...... 304 transmitter ....................................................... 299
? 2010-2011 microchip technology inc. preliminary ds41414c-page 439 pic16(l)f1946/1947 baud rate generator (brg) associated registers ........................................ 310 auto baud rate detect ..................................... 313 baud rate error, calculating ............................ 309 baud rates, asynchronous modes .................. 310 formulas ........................................................... 309 high baud rate select (brgh bit) .................. 309 clock polarity synchronous mode ........................................... 317 data polarity asynchronous receive ..................................... 302 data polarity asynchronous transmit .................................... 299 synchronous mode ........................................... 317 interrupts asynchronous receive ..................................... 303 asynchronous transmit .................................... 299 synchronous master mode ............................... 317, 322 associated registers, receive ......................... 321 associated registers, transmit ................ 318, 323 reception.......................................................... 320 transmission .................................................... 317 synchronous slave mode associated registers, receive ......................... 324 reception.......................................................... 324 transmission .................................................... 322 extended instruction set addfsr ................................................................... 379 f fail-safe clock monitor....................................................... 73 fail-safe condition clearing ....................................... 73 fail-safe detection ..................................................... 73 fail-safe operation..................................................... 73 reset or wake-up from sleep..................................... 73 firmware instructions........................................................ 375 fixed voltage reference (fvr) associated registers ................................................ 156 flash program memory .................................................... 111 erasing...................................................................... 116 modifying................................................................... 120 writing....................................................................... 116 fsr register ...... 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47 fvrcon (fixed voltage reference control) register ..... 156 i i 2 c mode (msspx) acknowledge sequence timing................................ 282 bus collision during a repeated start condition ................... 287 during a stop condition.................................... 288 effects of a reset...................................................... 283 i 2 c clock rate w/brg.............................................. 290 master mode operation .......................................................... 274 reception.......................................................... 280 start condition timing .............................. 276, 277 transmission .................................................... 278 multi-master communication, bus collision and arbitration ......................................................... 283 multi-master mode .................................................... 283 read/write bit information (r/w bit) ........................ 259 slave mode transmission .................................................... 264 sleep operation ........................................................ 283 stop condition timing .............................................. 282 indf register ...... 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47 indirect addressing ............................................................. 51 instruction format............................................................. 376 instruction set................................................................... 375 addlw..................................................................... 379 addwf .................................................................... 379 addwfc.................................................................. 379 andlw..................................................................... 379 andwf .................................................................... 379 bra .......................................................................... 380 call......................................................................... 381 callw ..................................................................... 381 lslf ......................................................................... 383 lsrf ........................................................................ 383 movf ....................................................................... 383 moviw ..................................................................... 384 movlb ..................................................................... 384 movwi ..................................................................... 385 option.................................................................... 385 reset...................................................................... 385 subwfb .................................................................. 387 tris ......................................................................... 388 bcf .......................................................................... 380 bsf........................................................................... 380 btfsc...................................................................... 380 btfss ...................................................................... 380 call......................................................................... 381 clrf ........................................................................ 381 clrw ....................................................................... 381 clrwdt .................................................................. 381 comf ....................................................................... 381 decf........................................................................ 381 decfsz ................................................................... 382 goto ....................................................................... 382 incf ......................................................................... 382 incfsz..................................................................... 382 iorlw...................................................................... 382 iorwf...................................................................... 382 movlw .................................................................... 384 movwf.................................................................... 384 nop.......................................................................... 385 retfie..................................................................... 386 retlw ..................................................................... 386 return................................................................... 386 rlf........................................................................... 386 rrf .......................................................................... 387 sleep ...................................................................... 387 sublw..................................................................... 387 subwf..................................................................... 387 swapf..................................................................... 388 xorlw .................................................................... 388 xorwf .................................................................... 388 intcon register................................................................ 93 internal oscillator block intosc specifications ................................................... 406 internal sampling switch (r ss ) impedance ..................... 170 internet address ............................................................... 445 interrupt-on-change......................................................... 151 associated registers................................................ 153 interrupts ............................................................................ 87 adc .......................................................................... 165 associated registers w/ interrupts ............................ 102
pic16(l)f1946/1947 ds41414c-page 440 preliminary ? 2010-2011 microchip technology inc. configuration word associated w/ portf............... 145 configuration word w/ clock sources ........................ 77 configuration word w/ ldo ...................................... 103 tmr1 ........................................................................ 201 intosc specifications ..................................................... 406 iocbf register................................................................. 152 iocbn register ................................................................ 152 iocbp register................................................................. 152 l lata register................................................................... 128 latb register................................................................... 131 latc register................................................................... 134 latd register................................................................... 137 late register................................................................... 141 latf register ................................................................... 144 latg register .................................................................. 147 lcd associated registers ................................................ 368 bias voltage generation ................................... 343, 344 clock source selection ............................................. 342 configuring the module ............................................. 367 disabling the module ................................................ 367 frame frequency...................................................... 350 interrupts................................................................... 363 lcdcon register .................................................... 335 lcdps register........................................................ 335 multiplex types ......................................................... 350 operation during sleep ............................................ 365 pixel control.............................................................. 350 prescaler................................................................... 342 segment enables...................................................... 350 waveform generation ............................................... 352 lcdcon register..................................................... 335, 337 lcdcst register ............................................................. 340 lcddatax registers ............................................... 341, 348 lcdps register........................................................ 335, 338 lp bits....................................................................... 342 lcdref register ............................................................. 339 lcdrl register ................................................................ 348 lcdsen registers ............................................................ 341 liquid crystal display (lcd) driver .................................. 335 load conditions ................................................................ 404 lslf.................................................................................. 383 lsrf ................................................................................. 383 m master synchronous serial port. see msspx mclr .................................................................................. 82 internal ........................................................................ 82 memory organization data ...................................................................... 24, 27 program ...................................................................... 21 microchip internet web site .............................................. 445 migrating from other pic microcontroller devices............. 435 moviw.............................................................................. 384 movlb.............................................................................. 384 movwi.............................................................................. 385 mplab asm30 assembler, linker, librarian ................... 426 mplab integrated development environment software .. 425 mplab pm3 device programmer..................................... 428 mplab real ice in-circuit emulator system................. 427 mplink object linker/mplib object librarian ................ 426 msspx .............................................................................. 243 i 2 c mode ................................................................... 254 i 2 c mode operation .................................................. 255 spi mode .................................................................. 246 sspxbuf register ................................................... 249 sspxsr register ..................................................... 249 o opcode field descriptions............................................. 375 option ............................................................................ 385 option register.............................................................. 195 osccon register.............................................................. 75 oscillator associated registers .................................................. 77 oscillator module ................................................................ 61 ech ............................................................................ 61 ecl............................................................................. 61 ecm............................................................................ 61 hs............................................................................... 61 intosc ...................................................................... 61 lp ............................................................................... 61 rc .............................................................................. 61 xt ............................................................................... 61 oscillator parameters ....................................................... 406 oscillator specifications.................................................... 405 oscillator start-up timer (ost) specifications ........................................................... 410 oscillator switching fail-safe clock monitor .............................................. 73 two-speed clock start-up.......................................... 71 oscstat register ............................................................ 76 osctune register............................................................ 77 p p1a/p1b/p1c/p1d. see enhanced capture/compare/ pwm (eccp)............................................................ 222 packaging ......................................................................... 429 marking ............................................................. 429, 430 pdip details ............................................................. 430 pcl and pclath............................................................... 20 pcl register33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47 pclath register33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47 pcon register ............................................................. 34, 85 pie1 register................................................................ 34, 94 pie2 register................................................................ 34, 95 pie3 register................................................................ 34, 96 pie4 register...................................................................... 34 pin diagram pic16f/lf1946/47, 64-pin tqfp/qfn ........................ 5 pinout descriptions pic16f/lf1946/47 ..................................................... 13 pir1 register ............................................................... 33, 98 pir2 register ............................................................... 33, 99 pir3 register ............................................................. 33, 100 pir4 register ....................................................... 33, 97, 101 porta ............................................................................. 127 ansela register ..................................................... 127 associated registers ................................................ 129 configuration word w/ porta................................. 129 lata register ............................................................ 35 porta register ......................................................... 33 specifications ........................................................... 408 porta register ............................................................... 128 portb ............................................................................. 130 associated registers ................................................ 132 interrupt-on-change ................................................. 130 latb register ............................................................ 35
? 2010-2011 microchip technology inc. preliminary ds41414c-page 441 pic16(l)f1946/1947 p1b/p1c/p1d. see enhanced capture/compare/ pwm+ (eccp+) ............................................... 130 pin functions and output priorities .......................... 130 portb register ......................................................... 33 portb register ............................................................... 131 portc ............................................................................. 133 associated registers ................................................ 135 latc register ............................................................ 35 p1a. see enhanced capture/compare/pwm+ (eccp+) ........................................................... 133 pin functions and output priorities .......................... 133 portc register ......................................................... 33 specifications............................................................ 408 portc register ............................................................... 134 portd ............................................................................. 136 associated registers ................................................ 138 latd register ............................................................ 35 p1b/p1c/p1d. see enhanced capture/compare/ pwm+ (eccp+) ............................................... 136 pin functions and output priorities .......................... 136 portd register ......................................................... 33 portd register ............................................................... 137 porte.............................................................................. 139 ansele register ..................................................... 139 associated registers ................................................ 141 late register............................................................. 35 pin functions and output priorities .......................... 139 porte register ......................................................... 33 porte register ............................................................... 140 portf .............................................................................. 142 anself register...................................................... 142 associated registers ................................................ 145 latf register............................................................. 40 pin functions and output priorities .......................... 143 portf register ......................................................... 38 portf register ............................................................... 144 portg ............................................................................. 146 anselg register ..................................................... 146 associated registers ................................................ 149 latg register ............................................................ 40 pin descriptions and output priorities ...................... 146 portg register......................................................... 38 portg register............................................................... 147 power-down mode (sleep) ............................................... 105 associated registers ................................................ 106 power-on reset .................................................................. 80 power-up timer (pwrt) .................................................... 80 specifications............................................................ 410 pr2 register................................................................. 33, 41 precision internal oscillator parameters........................... 406 program memory ................................................................ 21 map and stack ............................................................ 27 map and stack (pic16f/lf1946/47) .................... 22, 27 map and stack (pic16f1946) .................................... 22 map and stack (pic16f1947) .................................... 22 map and stack pic16f/lf1946/47) ........................... 21 programming mode exit ..................................................... 82 programming, device instructions .................................... 375 pstrxcon register ........................................................ 241 pwm (eccp module) pwm steering........................................................... 233 steering synchronization .......................................... 234 pwm mode. see enhanced capture/compare/pwm ...... 222 pwm steering ................................................................... 233 pwmxcon register ......................................................... 240 r rc2reg register .............................................................. 42 rc2sta register ............................................................... 42 rcreg............................................................................. 304 rcreg register ................................................................ 36 rcsta register ......................................................... 36, 307 reader response............................................................. 446 read-modify-write operations ......................................... 375 register rcreg register ...................................................... 313 registers adcon0 (adc control 0) ........................................ 166 adcon1 (adc control 1) ........................................ 167 adresh (adc result high) with adfm = 0) .......... 168 adresh (adc result high) with adfm = 1) .......... 169 adresl (adc result low) with adfm = 0)............ 168 adresl (adc result low) with adfm = 1)............ 169 ansela (porta analog select) ............................ 129 ansele (porte analog select) ............................ 141 anself (portf analog select)............................. 145 apfcon (alternate pin function control) ............... 126 baudcon (baud rate control)............................... 308 borcon brown-out reset control) .......................... 81 ccptmrs0 (pwm timer selection control 0) ........ 237 ccptmrs1 (pwm timer selection control 1) ........ 238 ccpxas (ccpx auto-shutdown control) ................ 239 ccpxcon (eccpx control) .................................... 236 cmout (comparator output) .................................. 184 cmxcon0 (cx control) ............................................ 183 cmxcon1 (cx control 1)......................................... 184 configuration word 1.................................................. 56 configuration word 2.................................................. 58 cpscon0 (capacitive sensing control register 0) 331 cpscon1 (capacitive sensing control register 1) 332 daccon0 ................................................................ 176 daccon1 ................................................................ 176 eeadrl (eeprom address) .................................. 122 eecon1 (eeprom control 1) ................................ 123 eecon2 (eeprom control 2) ................................ 124 eedath (eeprom data) ....................................... 122 eedatl (eeprom data) ........................................ 122 fvrcon .................................................................. 156 intcon (interrupt control) ........................................ 93 iocbf (interrupt-on-change flag)........................... 152 iocbn (interrupt-on-change negative edge).......... 152 iocbp (interrupt-on-change positive edge)............ 152 lata (data latch porta) ...................................... 128 latb (data latch portb) ...................................... 131 latc (data latch portc) ...................................... 134 latd (data latch portd) ...................................... 137 late (data latch porte) ...................................... 141 latf (data latch portf)....................................... 144 latg (data latch portg)...................................... 147 lcdcon (lcd control) ........................................... 337 lcdcst (lcd contrast control) ............................. 340 lcddatax (lcd data).................................... 341, 348 lcdps (lcd phase)................................................ 338 lcdref (lcd reference voltage control) ............. 339 lcdrl (lcd reference voltage control)................ 348 lcdsen (lcd segment enable) ............................. 341 option_reg (option)......................................... 195 osccon (oscillator control)..................................... 75 oscstat (oscillator status) ..................................... 76 osctune (oscillator tuning).................................... 77 pcon (power control register)................................. 85
pic16(l)f1946/1947 ds41414c-page 442 preliminary ? 2010-2011 microchip technology inc. pcon (power control) ............................................... 85 pie1 (peripheral interrupt enable 1) ........................... 94 pie2 (peripheral interrupt enable 2) ........................... 95 pie3 (peripheral interrupt enable 3) ........................... 96 pir1 (peripheral interrupt register 1) ........................ 98 pir2 (peripheral interrupt request 2) ........................ 99 pir3 (peripheral interrupt request 3) ...................... 100 pir4 (peripheral interrupt request 4) ................ 97, 101 porta...................................................................... 128 portb...................................................................... 131 portc ..................................................................... 134 portd ..................................................................... 137 porte...................................................................... 140 portf ...................................................................... 144 portg ..................................................................... 147 pstrxcon (pwm steering control) ....................... 241 pwmxcon (enhanced pwm control) ..................... 240 rcxsta (receive status and control) ..................... 307 special function, summary ........................................ 33 srcon0 (sr latch control 0) ................................. 189 srcon1 (sr latch control 1) ................................. 190 sspxadd (msspx address and baud rate, i 2 c mode).......................................................... 295 sspxcon1 (msspx control 1) ................................ 292 sspxcon2 (sspx control 2) ................................... 293 sspxcon3 (sspx control 3) ................................... 294 sspxmsk (sspx mask) ........................................... 295 sspxstat (sspx status) ........................................ 291 status ...................................................................... 25 t1con (timer1 control)........................................... 205 t1gcon (timer1 gate control) ............................... 206 trisa (tri-state porta) ......................................... 128 trisb (tri-state portb) ......................................... 131 trisc (tri-state portc) ........................................ 134 trisd (tri-state portd) ........................................ 137 trise (tri-state porte) ......................................... 140 trisf (tri-state portf) ......................................... 144 trisg (tri-state portg) ........................................ 147 txcon ..................................................................... 211 txxsta (transmit status and control) .................... 306 wdtcon (watchdog timer control)........................ 109 wpub (weak pull-up portb) ................................. 132 wpug (weak pull-up portg) ................................ 148 reset .............................................................................. 385 reset instruction ................................................................. 82 resets ................................................................................. 79 associated registers .................................................. 86 revision history ................................................................ 435 s shoot-through current ...................................................... 232 software simulator (mplab sim)..................................... 427 sp2brg register ............................................................... 42 spbrg.............................................................................. 309 spbrg register ........................................................... 35, 36 spbrgh ........................................................................... 309 special event trigger........................................................ 164 special function registers (sfrs) ..................................... 33 spi mode (msspx) associated registers ................................................ 253 spi clock .................................................................. 249 sr latch ........................................................................... 187 associated registers w/ sr latch ............................. 191 srcon0 register............................................................. 189 srcon1 register............................................................. 190 ssp1add register ............................................................. 37 ssp1buf register ............................................................. 37 ssp1con1 register .......................................................... 37 ssp1con2 register .......................................................... 37 ssp1con3 register .......................................................... 37 ssp1msk register ............................................................ 37 ssp1stat register ........................................................... 37 ssp2add register............................................................. 37 ssp2buf register ............................................................. 37 ssp2con1 register .......................................................... 37 ssp2con2 register .......................................................... 37 ssp2con3 register .......................................................... 37 ssp2msk register ............................................................ 37 ssp2stat register ........................................................... 37 sspxadd register........................................................... 295 sspxcon1 register ........................................................ 292 sspxcon2 register ........................................................ 293 sspxcon3 register ........................................................ 294 sspxmsk register........................................................... 295 sspxov............................................................................ 280 sspxov status flag ........................................................ 280 sspxstat register ......................................................... 291 r/w bit ..................................................................... 259 stack................................................................................... 49 accessing ................................................................... 49 reset .......................................................................... 51 stack overflow/underflow .................................................. 82 status register ............................................................... 25 subwfb .......................................................................... 387 t t1con register ......................................................... 33, 205 t1gcon register ............................................................ 206 t2con register ........................................................... 33, 41 temperature indicator module.......................................... 157 thermal considerations (pic16f/lf1946/47).................. 403 timer0............................................................................... 193 associated registers ................................................ 195 operation .................................................................. 193 specifications ........................................................... 411 timer1............................................................................... 197 associated registers ................................................. 207 asynchronous counter mode ................................... 199 reading and writing ......................................... 199 clock source selection............................................. 198 interrupt .................................................................... 201 operation .................................................................. 198 operation during sleep ............................................ 201 oscillator................................................................... 199 prescaler .................................................................. 199 specifications ........................................................... 411 timer1 gate selecting source .............................................. 199 tmr1h register ....................................................... 197 tmr1l register........................................................ 197 timer2 associated registers ................................................. 212 timer2/4/6......................................................................... 209 associated registers ................................................. 212 timers timer1 t1con ............................................................. 205 t1gcon........................................................... 206 timer2/4/6 txcon ............................................................. 211 timing diagrams a/d conversion......................................................... 413
? 2010-2011 microchip technology inc. preliminary ds41414c-page 443 pic16(l)f1946/1947 a/d conversion (sleep mode) .................................. 413 acknowledge sequence ........................................... 282 asynchronous reception .......................................... 305 asynchronous transmission..................................... 300 asynchronous transmission (back to back) ............ 301 auto wake-up bit (wue) during normal operation . 315 auto wake-up bit (wue) during sleep .................... 315 automatic baud rate calculator............................... 314 baud rate generator with clock arbitration ............. 275 brg reset due to sda arbitration during start condition........................................................... 286 brown-out reset (bor) ............................................ 409 brown-out reset situations ........................................ 81 bus collision during a repeated start condition (case 1) ............................................................ 287 bus collision during a repeated start condition (case 2) ............................................................ 287 bus collision during a start condition (scl = 0) ..... 286 bus collision during a stop condition (case 1) ....... 288 bus collision during a stop condition (case 2) ....... 288 bus collision during start condition (sda only) ...... 285 bus collision for transmit and acknowledge............ 284 clkout and i/o....................................................... 407 clock synchronization .............................................. 272 clock timing ............................................................. 405 comparator output ................................................... 177 enhanced capture/compare/pwm (eccp) ............. 411 fail-safe clock monitor (fscm) ................................. 74 first start bit timing ................................................. 276 full-bridge pwm output ........................................... 227 half-bridge pwm output .................................. 225, 232 i 2 c bus data ............................................................. 419 i 2 c bus start/stop bits.............................................. 418 i 2 c master mode (7 or 10-bit transmission) ............ 279 i 2 c master mode (7-bit reception)........................... 281 i 2 c stop condition receive or transmit mode ......... 283 int pin interrupt.......................................................... 91 internal oscillator switch timing................................. 69 lcd interrupt timing in quarter-duty cycle drive.... 364 lcd sleep entry/exit when slpen = 1 or cs = 00 . 366 pwm auto-shutdown ................................................ 231 firmware restart .............................................. 231 pwm direction change ............................................ 228 pwm direction change at near 100% duty cycle ... 229 pwm output (active-high)........................................ 223 pwm output (active-low) ........................................ 224 repeat start condition.............................................. 277 reset start-up sequence............................................ 83 reset, wdt, ost and power-up timer ................... 408 send break character sequence ............................. 316 spi master mode (cke = 1, smp = 1) ..................... 416 spi mode (master mode).......................................... 249 spi slave mode (cke = 0) ....................................... 417 spi slave mode (cke = 1) ....................................... 417 synchronous reception (master mode, sren) ....... 321 synchronous transmission....................................... 318 synchronous transmission (through txen) ........... 318 timer0 and timer1 external clock ........................... 410 timer1 incrementing edge........................................ 201 two speed start-up .................................................... 72 type-a in 1/2 mux, 1/2 bias drive ............................ 353 type-a in 1/2 mux, 1/3 bias drive ............................ 355 type-a in 1/3 mux, 1/2 bias drive ............................ 357 type-a in 1/3 mux, 1/3 bias drive ............................ 359 type-a in 1/4 mux, 1/3 bias drive ............................ 361 type-a/type-b in static drive .................................. 352 type-b in 1/2 mux, 1/2 bias drive ............................ 354 type-b in 1/2 mux, 1/3 bias drive ............................ 356 type-b in 1/3 mux, 1/2 bias drive ............................ 358 type-b in 1/3 mux, 1/3 bias drive ............................ 360 type-b in 1/4 mux, 1/3 bias drive ............................ 362 usart synchronous receive (master/slave) ......... 415 usart synchronous transmission (master/slave). 414 wake-up from interrupt............................................. 106 timing diagrams and specifications pll clock ................................................................. 406 timing parameter symbology .......................................... 404 timing requirements i 2 c bus data............................................................. 420 i2c bus start/stop bits............................................. 419 spi mode.................................................................. 418 tmr0 register.................................................................... 33 tmr1h register ................................................................. 33 tmr1l register.................................................................. 33 tmr2 register.............................................................. 33, 41 tris ................................................................................. 388 trisa register........................................................... 34, 128 trisb ............................................................................... 130 trisb register........................................................... 34, 131 trisc ............................................................................... 133 trisc register........................................................... 34, 134 trisd ............................................................................... 136 trisd register........................................................... 34, 137 trise ............................................................................... 139 trise register........................................................... 34, 140 trisf ............................................................................... 142 trisf register ........................................................... 39, 144 trisg............................................................................... 146 trisg register .......................................................... 39, 147 two-speed clock start-up mode........................................ 71 tx2reg register ............................................................... 42 tx2sta register................................................................ 42 txcon (timer2/4/6) register .......................................... 211 txreg ............................................................................. 299 txreg register ................................................................. 36 txsta register.......................................................... 36, 306 brgh bit .................................................................. 309 u usart synchronous master mode requirements, synchronous receive .............. 415 requirements, synchronous transmission...... 415 timing diagram, synchronous receive ........... 415 timing diagram, synchronous transmission... 414 v v ref . s ee adc reference voltage w wake-up on break ............................................................ 314 wake-up using interrupts ................................................. 106 watchdog timer (wdt)...................................................... 82 modes....................................................................... 108 specifications ........................................................... 410 wcol ....................................................... 275, 278, 280, 282 wcol status flag.................................... 275, 278, 280, 282 wdtcon register ........................................................... 109 wpub register................................................................. 132 wpug register ................................................................ 148 write protection .................................................................. 59
pic16(l)f1946/1947 ds41414c-page 444 preliminary ? 2010-2011 microchip technology inc. www address.................................................................. 445 www, on-line support........................................................ 9
? 2010-2011 microchip technology inc. preliminary ds41414c-page 445 pic16(l)f1946/1947 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 ? data sheets and errata, application notes and sample programs, design resources, user?s guides and hardware support documents, latest software releases and archived software ? general technical support ? frequently asked questions (faq), technical support requests, online discussion groups, microchip consultant program member listing ? business of microchip ? 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 microchip?s 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
pic16(l)f1946/1947 ds41414c-page 446 preliminary ? 2010-2011 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 which 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 document. 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: (______) _________ - _________ ds41414c pic16(l)f1946/1947 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?
? 2010-2011 microchip technology inc. preliminary ds41414c-page 447 pic16(l)f1946/1947 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: pic16f1946, pic16lf1946, pic16f1946t, pic16lf1946t (1) pic16f1947, pic16lf1947, pic16f1947t, pic16lf1947t (1) temperature range: i= -40 ? c to +85 ? c e= -40 ? c to +125 ? c package: mr = micro lead frame (qfn) pt = tqfp (thin quad flatpack) pattern: 3-digit pattern code for qtp (blank otherwise) examples: a) pic16lf1946 - e/mr = extended temp., qfn package, low-voltage v dd limits. b) pic16f1947 - i/pt = industrial temp., tqfp package, standard v dd limits. note 1: f = standard voltage range lf = low voltage range 2: t = in tape and reel for qfn and tqfp packages only.
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