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PIC17C7XX
High-Performance 8-bit CMOS EPROM Microcontrollers with 10-bit A/D
Microcontroller Core Features:
* Only 58 single word instructions to learn * All single cycle instructions (121 ns), except for program branches and table reads/writes which are two-cycle * Operating speed: - DC - 33 MHz clock input - DC - 121 ns instruction cycle * 8 x 8 Single-Cycle Hardware Multiplier * Interrupt capability * 16 level deep hardware stack * Direct, indirect, and relative addressing modes * Internal/external program memory execution, capable of addressing 64 K x 16 program memory space Memory Device Program (x16) PIC17C752 PIC17C756A PIC17C762 PIC17C766 8K 16 K 8K 16 K Data (x8) 678 902 678 902
Pin Diagrams
RH1 RH0 RD2/AD10 RD3/AD11 RD4/AD12 RD5/AD13 RD6/AD14 RD7/AD15 RC0/AD0 VDD NC VSS RC1/AD1 RC2/AD2 RC3/AD3 RC4/AD4 RC5/AD5 RC6/AD6 RC7/AD7 RJ7 RJ6
84 PLCC
RH2 RH3 RD1/AD9 RD0/AD8 RE0/ALE RE1/OE RE2/WR RE3/CAP4 MCLR/VPP TEST NC VSS VDD RF7/AN11 RF6/AN10 RF5/AN9 RF4/AN8 RF3/AN7 RF2/AN6 RH4/AN12 RH5/AN13
1110 9 8 7 6 5 4 3 2 1 84 838281 807978777675 12 74 13 73 14 72 15 71 70 16 69 17 68 18 67 19 66 20 65 21 64 22 63 23 62 24 61 25 60 26 59 27 58 28 57 29 56 30 31 55 32 54 33343536373839404142434445 464748 49 50 51 52 53
PIC17C76X
RJ5 RJ4 RA0/INT RB0/CAP1 RB1/CAP2 RB3/PWM2 RB4/TCLK12 RB5/TCLK3 RB2/PWM1 VSS NC OSC2/CLKOUT OSC1/CLKIN VDD RB7/SDO RB6/SCK RA3/SDI/SDA RA2/SS/SCL RA1/T0CKI RJ3 RJ2
Special Microcontroller Features:
* Power-on Reset (POR), Power-up Timer (PWRT) and Oscillator Start-up Timer (OST) * Watchdog Timer (WDT) with its own on-chip RC oscillator for reliable operation * Brown-out Reset * Code protection * Power saving SLEEP mode * Selectable oscillator options
Peripheral Features:
* * * * * * * * * * Up to 66 I/O pins with individual direction control 10-bit, multi-channel Analog-to-Digital converter High current sink/source for direct LED drive Four capture input pins - Captures are 16-bit, max resolution 121 ns Three PWM outputs (resolution is 1 to 10-bits) TMR0: 16-bit timer/counter with 8-bit programmable prescaler TMR1: 8-bit timer/counter TMR2: 8-bit timer/counter TMR3: 16-bit timer/counter Two Universal Synchronous Asynchronous Receiver Transmitters (USART/SCI) with independent baud rate generators Synchronous Serial Port (SSP) with SPITM and I2CTM modes (including I2C Master mode)
CMOS Technology:
* Low power, high speed CMOS EPROM technology * Fully static design * Wide operating voltage range (3.0V to 5.5V) * Commercial and Industrial temperature ranges * Low power consumption - < 5 mA @ 5V, 4 MHz - 100 A typical @ 4.5V, 32 kHz - < 1 A typical standby current @ 5V
*
2000 Microchip Technology Inc.
RH6/AN14 RH7/AN15 RF1/AN5 RF0/AN4 AVDD AVSS RG3/AN0/VREF+ RG2/AN1/VREFRG1/AN2 RG0/AN3 NC VSS VDD RG4/CAP3 RG5/PWM3 RG7/TX2/CK2 RG6/RX2/DT2 RA5/TX1/CK1 RA4/RX1/DT1 RJ0 RJ1
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PIC17C7XX
Pin Diagrams cont.'d
68-Pin PLCC
RD2/AD10 RD3/AD11 RD4/AD12 RD5/AD13 RD6/AD14 RD7/AD15 RC0/AD0 VDD NC VSS RC1/AD1 RC2/AD2 RC3/AD3 RC4/AD4 RC5/AD5 RC6/AD6 RC7/AD7 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 9 8 7 6 5 4 3 2 1 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44
RD1/AD9 RD0/AD8 RE0/ALE RE1/OE RE2/WR RE3/CAP4 MCLR/VPP TEST NC VSS VDD RF7/AN11 RF6/AN10 RF5/AN9 RF4/AN8 RF3/AN7 RF2/AN6
PIC17C75X
RA0/INT RB0/CAP1 RB1/CAP2 RB3/PWM2 RB4/TCLK12 RB5/TCLK3 RB2/PWM1 VSS NC OSC2/CLKOUT OSC1/CLKIN VDD RB7/SDO RB6/SCK RA3/SDI/SDA RA2/SS/SCL RA1/T0CKI
64-Pin TQFP
64 63 62 61 60 59 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33
RD2/AD10 RD3/AD11 RD4/AD12 RD5/AD13 RD6/AD14 RD7/AD15 RC0/AD0 VDD VSS RC1/AD1 RC2/AD2 RC3/AD3 RC4/AD4 RC5/AD5 RC6/AD6 RC7/AD7
RF1/AN5 RF0/AN4 AVDD AVSS RG3/AN0/VREF+ RG2/AN1/VREFRG1/AN2 RG0/AN3 NC VSS VDD RG4/CAP3 RG5/PWM3 RG7/TX2/CK2 RG6/RX2/DT2 RA5/TX1/CK1 RA4/RX1/DT1
27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
RD1/AD9 RD0/AD8 RE0/ALE RE1/OE RE2/WR RE3/CAP4 MCLR/VPP TEST VSS VDD RF7/AN11 RF6/AN10 RF5/AN9 RF4/AN8 RF3/AN7 RF2/AN6
PIC17C75X
RA0/INT RB0/CAP1 RB1/CAP2 RB3/PWM2 RB4/TCLK12 RB5/TCLK3 RB2/PWM1 VSS OSC2/CLKOUT OSC1/CLKIN VDD RB7/SDO RB6/SCK RA3/SDI/SDA RA2/SS/SCL RA1/T0CKI
RF1/AN5 RF0/AN4 AVDD AVSS RG3/AN0/VREF+ RG2/AN1/VREFRG1/AN2 RG0/AN3 VSS VDD RG4/CAP3 RG5/PWM3 RG7/TX2/CK2 RG6/RX2/DT2 RA5/TX1/CK1 RA4/RX1/DT1
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
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PIC17C7XX
Pin Diagrams cont.'d
84-pin PLCC
RH1 RH0 RD2/AD10 RD3/AD11 RD4/AD12 RD5/AD13 RD6/AD14 RD7/AD15 RC0/AD0 VDD NC VSS RC1/AD1 RC2/AD2 RC3/AD3 RC4/AD4 RC5/AD5 RC6/AD6 RC7/AD7 RJ7 RJ6 RH2 RH3 RD1/AD9 RD0/AD8 RE0/ALE RE1/OE RE2/WR RE3/CAP4 MCLR/VPP TEST NC VSS VDD RF7/AN11 RF6/AN10 RF5/AN9 RF4/AN8 RF3/AN7 RF2/AN6 RH4/AN12 RH5/AN13 11 10 9 8 7 6 5 4 3 2 1 84 83828180 79787776 75 12 74 13 73 14 72 15 71 16 70 69 17 68 18 67 19 66 20 65 21 64 22 63 23 62 24 61 25 60 26 59 27 58 28 57 29 56 30 31 55 32 54 333435363738394041424344 4546 4748 49 50 51 52 53
PIC17C76X
RJ5 RJ4 RA0/INT RB0/CAP1 RB1/CAP2 RB3/PWM2 RB4/TCLK12 RB5/TCLK3 RB2/PWM1 VSS NC OSC2/CLKOUT OSC1/CLKIN VDD RB7/SDO RB6/SCK RA3/SDI/SDA RA2/SS/SCL RA1/T0CKI RJ3 RJ2
RH2 RH3 RD1/AD9 RD0/AD8 RE0/ALE RE1/OE RE2/WR RE3/CAP4 MCLR/VPP TEST VSS VDD RF7/AN11 RF6/AN10 RF5/AN9 RF4/AN8 RF3/AN7 RF2/AN6 RH4/AN12 RH5/AN13
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
RH1 RH0 RD2/AD10 RD3/AD11 RD4/AD12 RD5/AD13 RD6/AD14 RD7/AD15 RC0/AD0 VDD VSS RC1/AD1 RC2/AD2 RC3/AD3 RC4/AD4 RC5/AD5 RC6/AD6 RC7/AD7 RJ7 RJ6 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 RJ5 RJ4 RA0/INT RB0/CAP1 RB1/CAP2 RB3/PWM2 RB4/TCLK12 RB5/TCLK3 RB2/PWM1 VSS OSC2/CLKOUT OSC1/CLKIN VDD RB7/SDO RB6/SCK RA3/SDI/SDA RA2/SS/SCL RA1/T0CKI RJ3 RJ2
80-Pin TQFP
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 3637 38 39 40
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RH6/AN14 RH7/AN15 RF1/AN5 RF0/AN4 AVDD AVSS RG3/AN0/VREF+ RG2/AN1/VREFRG1/AN2 RG0/AN3 VSS VDD RG4/CAP3 RG5/PWM3 RG7/TX2/CK2 RG6/RX2/DT2 RA5/TX1/CK1 RA4/RX1/DT1 RJ0 RJ1
RH6/AN14 RH7/AN15 RF1/AN5 RF0/AN4 AVDD AVSS RG3/AN0/VREF+ RG2/AN1/VREFRG1/AN2 RG0/AN3 NC VSS VDD RG4/CAP3 RG5/PWM3 RG7/TX2/CK2 RG6/RX2/DT2 RA5/TX1/CK1 RA4/RX1/DT1 RJ0 RJ1
PIC17C76X
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PIC17C7XX
Table of Contents
1.0 Overview ........................................................................................................................................................ 7 2.0 Device Varieties ............................................................................................................................................. 9 3.0 Architectural Overview ................................................................................................................................. 11 4.0 On-chip Oscillator Circuit ............................................................................................................................. 17 5.0 Reset............................................................................................................................................................ 23 6.0 Interrupts...................................................................................................................................................... 33 7.0 Memory Organization................................................................................................................................... 43 8.0 Table Reads and Table Writes .................................................................................................................... 59 9.0 Hardware Multiplier ...................................................................................................................................... 67 10.0 I/O Ports....................................................................................................................................................... 71 11.0 Overview of Timer Resources...................................................................................................................... 95 12.0 Timer0.......................................................................................................................................................... 97 13.0 Timer1, Timer2, Timer3, PWMs and Captures .......................................................................................... 101 14.0 Universal Synchronous Asynchronous Receiver Transmitter (USART) Modules...................................... 117 15.0 Master Synchronous Serial Port (MSSP) Module...................................................................................... 133 16.0 Analog-to-Digital Converter (A/D) Module ................................................................................................. 179 17.0 Special Features of the CPU ..................................................................................................................... 191 18.0 Instruction Set Summary............................................................................................................................ 197 19.0 Development Support ................................................................................................................................ 233 20.0 PIC17C7XX Electrical Characteristics ....................................................................................................... 239 21.0 PIC17C7XX DC and AC Characteristics.................................................................................................... 267 22.0 Packaging Information ............................................................................................................................... 281 Appendix A: Modifications ....................................................................................................................................... 287 Appendix B: Compatibility........................................................................................................................................ 287 Appendix C: What's New ......................................................................................................................................... 288 Appendix D: What's Changed.................................................................................................................................. 288 Index .......................................................................................................................................................................... 289 On-Line Support .......................................................................................................................................................... 299 Reader Response ....................................................................................................................................................... 300 Product Identification System...................................................................................................................................... 301
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PIC17C7XX
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Errata
An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision of silicon and revision of document to which it applies. To determine if an errata sheet exists for a particular device, please check with one of the following: * Microchip's Worldwide Web site; http://www.microchip.com * Your local Microchip sales office (see last page) * The Microchip Corporate Literature Center; U.S. FAX: (480) 792-7277 When contacting a sales office or the literature center, please specify which device, revision of silicon and data sheet (include literature number) you are using.
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PIC17C7XX
1.0 OVERVIEW
This data sheet covers the PIC17C7XX group of the PIC17CXXX family of microcontrollers. The following devices are discussed in this data sheet: * * * * PIC17C752 PIC17C756A PIC17C762 PIC17C766 A highly reliable Watchdog Timer with its own on-chip RC oscillator provides protection against software malfunction. There are four configuration options for the device operational mode: * * * * Microprocessor Microcontroller Extended microcontroller Protected microcontroller
The PIC17C7XX devices are 68/84-pin, EPROM based members of the versatile PIC17CXXX family of low cost, high performance, CMOS, fully static, 8-bit microcontrollers. All PICmicro(R) microcontrollers employ an advanced RISC architecture. The PIC17CXXX has enhanced core features, 16-level deep stack, and multiple internal and external interrupt sources. The separate instruction and data buses of the Harvard architecture allow a 16-bit wide instruction word with a separate 8-bit wide data path. The two stage instruction pipeline allows all instructions to execute in a single cycle, except for program branches (which require two cycles). A total of 58 instructions (reduced instruction set) are available. Additionally, a large register set gives some of the architectural innovations used to achieve a very high performance. For mathematical intensive applications, all devices have a single cycle 8 x 8 Hardware Multiplier. PIC17CXXX microcontrollers typically achieve a 2:1 code compression and a 4:1 speed improvement over other 8-bit microcontrollers in their class. PIC17C7XX devices have up to 902 bytes of RAM and 66 I/O pins. In addition, the PIC17C7XX adds several peripheral features, useful in many high performance applications, including: Four timer/counters Four capture inputs Three PWM outputs Two independent Universal Synchronous Asynchronous Receiver Transmitters (USARTs) * An A/D converter (multi-channel, 10-bit resolution) * A Synchronous Serial Port (SPI and I2C w/ Master mode) These special features reduce external components, thus reducing cost, enhancing system reliability and reducing power consumption. There are four oscillator options, of which the single pin RC oscillator provides a low cost solution, the LF oscillator is for low frequency crystals and minimizes power consumption, XT is a standard crystal and the EC is for external clock input. The SLEEP (power-down) mode offers additional power saving. Wake-up from SLEEP can occur through several external and internal interrupts and device RESETS. * * * *
The microprocessor and extended microcontroller modes allow up to 64K-words of external program memory. The device also has Brown-out Reset circuitry. This allows a device RESET to occur if the device VDD falls below the Brown-out voltage trip point (BVDD). The chip will remain in Brown-out Reset until VDD rises above BVDD. A UV erasable, CERQUAD packaged version (compatible with PLCC), is ideal for code development, while the cost-effective One-Time-Programmable (OTP) version is suitable for production in any volume. The PIC17C7XX fits perfectly in applications that require extremely fast execution of complex software programs. These include applications ranging from precise motor control and industrial process control to automotive, instrumentation, and telecom applications. The EPROM technology makes customization of application programs (with unique security codes, combinations, model numbers, parameter storage, etc.) fast and convenient. Small footprint package options (including die sales) make the PIC17C7XX ideal for applications with space limitations that require high performance. High speed execution, powerful peripheral features, flexible I/O, and low power consumption all at low cost make the PIC17C7XX ideal for a wide range of embedded control applications.
1.1
Family and Upward Compatibility
The PIC17CXXX family of microcontrollers have architectural enhancements over the PIC16C5X and PIC16CXX families. These enhancements allow the device to be more efficient in software and hardware requirements. Refer to Appendix A for a detailed list of enhancements and modifications. Code written for PIC16C5X or PIC16CXX can be easily ported to PIC17CXXX devices (Appendix B).
1.2
Development Support
The PIC17CXXX family is supported by a full featured macro assembler, a software simulator, an in-circuit emulator, a universal programmer, a "C" compiler and fuzzy logic support tools. For additional information, see Section 19.0.
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PIC17C7XX
TABLE 1-1: PIC17CXXX FAMILY OF DEVICES
PIC17C42A 33 MHz 2.5 - 6.0V 2K -- 232 Yes Yes Yes Yes Yes 2 2 1 -- -- Yes Yes Yes 11 Yes -- -- 33 25 mA 25 mA(1) 40-pin DIP 44-pin PLCC 44-pin MQFP 44-pin TQFP PIC17C43 33 MHz 2.5 - 6.0V 4K -- 454 Yes Yes Yes Yes Yes 2 2 1 -- -- Yes Yes Yes 11 Yes -- -- 33 25 mA 25 mA(1) PIC17C44 33 MHz 2.5 - 6.0V 8K -- 454 Yes Yes Yes Yes Yes 2 2 1 -- -- Yes Yes Yes 11 Yes -- -- 33 25 mA 25 mA(1) PIC17C752 33 MHz 3.0 - 5.5V 8K -- 678 Yes Yes Yes Yes Yes 4 3 2 12 Yes Yes Yes Yes 18 Yes Yes Yes 50 25 mA 25 mA(1) PIC17C756A 33 MHz 3.0 - 5.5V 16 K -- 902 Yes Yes Yes Yes Yes 4 3 2 12 Yes Yes Yes Yes 18 Yes Yes Yes 50 25 mA 25 mA(1) 64-pin TQFP 68-pin PLCC PIC17C762 33 MHz 3.0 - 5.5V 8K -- 678 Yes Yes Yes Yes Yes 4 3 2 16 Yes Yes Yes Yes 18 Yes Yes Yes 66 25 mA 25 mA(1) PIC17C766 33 MHz 3.0 - 5.5V 16 K -- 902 Yes Yes Yes Yes Yes 4 3 2 16 Yes Yes Yes Yes 18 Yes Yes Yes 66 25 mA 25 mA(1) Features Maximum Frequency of Operation Operating Voltage Range Program Memory ( x16) (EPROM) (ROM)
Data Memory (bytes) Hardware Multiplier (8 x 8) Timer0 (16-bit + 8-bit postscaler) Timer1 (8-bit) Timer2 (8-bit) Timer3 (16-bit) Capture inputs (16-bit) PWM outputs (up to 10-bit) USART/SCI A/D channels (10-bit) SSP (SPI/I2C w/Master mode) Power-on Reset Watchdog Timer External Interrupts Interrupt Sources Code Protect Brown-out Reset In-Circuit Serial Programming I/O Pins I/O High Source Current Capability Sink Package Types
40-pin DIP 40-pin DIP 64-pin TQFP 44-pin PLCC 44-pin PLCC 68-pin PLCC 44-pin 44-pin MQFP MQFP 44-pin TQFP 44-pin TQFP
80-pin TQFP 80-pin TQFP 84-pin PLCC 84-pin PLCC
Note 1: Pins RA2 and RA3 can sink up to 60 mA.
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PIC17C7XX
2.0 DEVICE VARIETIES
2.3
Each device has a variety of frequency ranges and packaging options. Depending on application and production requirements, the proper device option can be selected using the information in the PIC17C7XX Product Selection System section at the end of this data sheet. When placing orders, please use the "PIC17C7XX Product Identification System" at the back of this data sheet to specify the correct part number. When discussing the functionality of the device, memory technology and voltage range does not matter. There are two memory type options. These are specified in the middle characters of the part number. 1. 2. C, as in PIC17C756A. These devices have EPROM type memory. CR, as in PIC17CR756A. These devices have ROM type memory.
Quick-Turnaround-Production (QTP) Devices
Microchip offers a QTP Programming Service for factory production orders. This service is made available for users who choose not to program a medium to high quantity of units and whose code patterns have stabilized. The devices are identical to the OTP devices but with all EPROM locations and configuration options already programmed by the factory. Certain code and prototype verification procedures apply before production shipments are available. Please contact your local Microchip Technology sales office for more details.
2.4
Serialized Quick-Turnaround Production (SQTPsm) Devices
All these devices operate over the standard voltage range. Devices are also offered which operate over an extended voltage range (and reduced frequency range). Table 2-1 shows all possible memory types and voltage range designators for a particular device. These designators are in bold typeface.
Microchip offers a unique programming service, where a few user defined locations in each device are programmed with different serial numbers. The serial numbers may be random, pseudo-random or sequential. Serial programming allows each device to have a unique number which can serve as an entry code, password or ID number.
2.5
Read Only Memory (ROM) Devices
TABLE 2-1:
Memory Type
DEVICE MEMORY VARIETIES
Voltage Range Standard Extended PIC17LCXXX PIC17LCRXXX
Microchip offers masked ROM versions of several of the highest volume parts, thus giving customers a low cost option for high volume, mature products. ROM devices do not allow serialization information in the program memory space. For information on submitting ROM code, please contact your regional sales office. Note: Presently, NO ROM versions of the PIC17C7XX devices are available.
EPROM ROM Note:
PIC17CXXX PIC17CRXXX
Not all memory technologies are available for a particular device.
2.1
UV Erasable Devices
The UV erasable version, offered in CERQUAD package, is optimal for prototype development and pilot programs. The UV erasable version can be erased and reprogrammed to any of the configuration modes. Third party programmers also are available; refer to the Third Party Guide for a list of sources.
2.2
One-Time-Programmable (OTP) Devices
The availability of OTP devices is especially useful for customers expecting frequent code changes and updates. The OTP devices, packaged in plastic packages, permit the user to program them once. In addition to the program memory, the configuration bits must be programmed.
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PIC17C7XX
3.0 ARCHITECTURAL OVERVIEW
The WREG register is an 8-bit working register used for ALU operations. All PIC17CXXX devices have an 8 x 8 hardware multiplier. This multiplier generates a 16-bit result in a single cycle. The ALU is 8-bits wide and capable of addition, subtraction, shift and logical operations. Unless otherwise mentioned, arithmetic operations are two's complement in nature. Depending on the instruction executed, the ALU may affect the values of the Carry (C), Digit Carry (DC), Zero (Z) and Overflow (OV) bits in the ALUSTA register. The C and DC bits operate as a borrow and digit borrow out bit, respectively, in subtraction. See the SUBLW and SUBWF instructions for examples. Signed arithmetic is comprised of a magnitude and a sign bit. The overflow bit indicates if the magnitude overflows and causes the sign bit to change state. That is, if the result of 8-bit signed operations is greater than 127 (7Fh), or less than -128 (80h). Signed math can have greater than 7-bit values (magnitude), if more than one byte is used. The overflow bit only operates on bit6 (MSb of magnitude) and bit7 (sign bit) of each byte value in the ALU. That is, the overflow bit is not useful if trying to implement signed math where the magnitude, for example, is 11-bits. If the signed math values are greater than 7-bits (such as 15-, 24-, or 31-bit), the algorithm must ensure that the low order bytes of the signed value ignore the overflow status bit. Example 3-1 shows two cases of doing signed arithmetic. The Carry (C) bit and the Overflow (OV) bit are the most important status bits for signed math operations. The high performance of the PIC17CXXX can be attributed to a number of architectural features, commonly found in RISC microprocessors. To begin with, the PIC17CXXX uses a modified Harvard architecture. This architecture has the program and data accessed from separate memories. So, the device has a program memory bus and a data memory bus. This improves bandwidth over traditional von Neumann architecture, where program and data are fetched from the same memory (accesses over the same bus). Separating program and data memory further allows instructions to be sized differently than the 8-bit wide data word. PIC17CXXX opcodes are 16-bits wide, enabling single word instructions. The full 16-bit wide program memory bus fetches a 16-bit instruction in a single cycle. A twostage pipeline overlaps fetch and execution of instructions. Consequently, all instructions execute in a single cycle (121 ns @ 33 MHz), except for program branches and two special instructions that transfer data between program and data memory. The PIC17CXXX can address up to 64K x 16 of program memory space. The PIC17C752 and PIC17C762 integrate 8K x 16 of EPROM program memory on-chip. The PIC17C756A and PIC17C766 integrate 16K x 16 EPROM program memory on-chip. A simplified block diagram is shown in Figure 3-1. The descriptions of the device pins are listed in Table 3-1. Program execution can be internal only (Microcontroller or Protected Microcontroller mode), external only (Microprocessor mode), or both (Extended Microcontroller mode). Extended Microcontroller mode does not allow code protection. The PIC17CXXX can directly or indirectly address its register files or data memory. All special function registers, including the Program Counter (PC) and Working Register (WREG), are mapped in data memory. The PIC17CXXX has an orthogonal (symmetrical) instruction set that makes it possible to carry out any operation on any register using any addressing mode. This symmetrical nature and lack of `special optimal situations' make programming with the PIC17CXXX simple, yet efficient. In addition, the learning curve is reduced significantly. One of the PIC17CXXX family architectural enhancements from the PIC16CXX family, allows two file registers to be used in some two operand instructions. This allows data to be moved directly between two registers without going through the WREG register, thus increasing performance and decreasing program memory usage. The PIC17CXXX devices contain an 8-bit ALU and working register. The ALU is a general purpose arithmetic unit. It performs arithmetic and Boolean functions between data in the working register and any register file.
EXAMPLE 3-1:
Hex Value + = FFh 01h 00h
8-BIT MATH ADDITION
Unsigned Values 255 + 1 = 256 00h C bit = 1 OV bit = 0 DC bit = 1 Z bit = 1 -1 1 0 (FEh)
Signed Values + =
C bit = 1 OV bit = 0 DC bit = 1 Z bit = 1
C bit = 1 OV bit = 0 DC bit = 1 Z bit = 1
Hex Value + = 7Fh 01h 80h
Signed Values + = 127 1 128 00h
Unsigned Values 127 + 1 = 128 C bit = 0 OV bit = 1 DC bit = 1 Z bit = 0
C bit = 0 OV bit = 1 DC bit = 1 Z bit = 0
C bit = 0 OV bit = 1 DC bit = 1 Z bit = 0
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PIC17C7XX
FIGURE 3-1: PIC17C752/756A BLOCK DIAGRAM
PORTA RA0/INT RA1/T0CKI RA2/SS/SCL RA3/SDI/SDA RA4/RX1/DT1 RA5/TX1/CK1 IR<16> Q1, Q2, Q3, Q4 Clock Generator Power-on Reset OSC1, OSC2
WREG<8>
BITOP
Brown-out VDD, VSS Reset Chip_reset & Other Control Signals Watchdog Timer Test Mode Select MCLR, VPP
PORTB RB0/CAP1 RB1/CAP2 RB2/PWM1 RB3/PWM2 RB4/TCLK12 RB5/TCLK3 RB6/SCK RB7/SDO 8 PORTC RC0/AD0 RC1/AD1 RC2/AD2 RC3/AD3 RC4/AD4 RC5/AD5 RC6/AD6 RC7/AD7 PORTD RD0/AD8 RD1/AD9 RD2/AD10 RD3/AD11 RD4/AD12 RD5/AD13 RD6/AD14 RD7/AD15 PORTE
8 x 8 mult
ALU
Test
PRODH PRODL
Shifter
IR Latch <16> 8 8
BSR <7:4> IR <7:0> 12 RAM Address Buffer Data RAM 17C756A 902 x 8 17C752 678 x 8 Data Latch BSR Literal
16 Read/Write Decode for Registers Mapped in Data Space
F1 F9
Decode
Instruction Decode
ROM Latch <16>
8
Control Outputs
AD<15:0> PORTC, PORTD System Bus Interface ALE, WR, OE, PORTE SSP Interrupt Module Table Latch <16> Data Latch Program Memory (EPROM) 17C756A 16K x 16 17C752 8K x 16 Address Latch 16 16 Stack 16 x 16
RE0/ALE RE1/OE RE2/WR RE3/CAP4
PCLATH<8>
Table Pointer<16>
PORTF RF0/AN4 RF1/AN5 RF2/AN6 RF3/AN7 RF4/AN8 RF5/AN9 RF6/AN10 RF7/AN11 PORTG RG0/AN3 RG1/AN2 RG2/AN1/VREFRG3/AN0/VREF+ RG4/CAP3 RG5/PWM3 RG6/RX2/DT2 RG7/TX2/CK2 Timer1
PCH
PCL 16
16
Data Bus<8>
Timer0
Timer2
USART1
PWM1
PWM3
Capture2
10-bit A/D
Timer3
USART2
PWM2
Capture1
Capture3
Capture4
DS30289B-page 12
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 3-2:
RA0/INT RA1/T0CKI RA2/SS/SCL RA3/SDI/SDA RA4/RX1/DT1 RA5/TX1/CK1 PORTB RB0/CAP1 RB1/CAP2 RB2/PWM1 RB3/PWM2 RB4/TCLK12 RB5/TCLK3 RB6/SCK RB7/SDO PORTC RC0/AD0 RC1/AD1 RC2/AD2 RC3/AD3 RC4/AD4 RC5/AD5 RC6/AD6 RC7/AD7 PORTD RD0/AD8 RD1/AD9 RD2/AD10 RD3/AD11 RD4/AD12 RD5/AD13 RD6/AD14 RD7/AD15 PORTE RE0/ALE RE1/OE RE2/WR RE3/CAP4 PORTF RF0/AN4 RF1/AN5 RF2/AN6 RF3/AN7 RF4/AN8 RF5/AN9 RF6/AN10 RF7/AN11 PORTG RG0/AN3 RG1/AN2 RG2/AN1/VREFRG3/AN0/VREF+ RG4/CAP3 RG5/PWM3 RG6/RX2/DT2 RG7/TX2/CK2 PORTH RH0 RH1 RH2 RH3 RH4/AN12 RH5/AN13 RH6/AN14 RH7/AN15 Timer0 Timer2 USART1 PWM1 PWM3 16 PCH PCL 16 Data Bus<8> PORTJ RJ0 RJ1 RJ2 RJ3 RJ4 RJ5 RJ6 RJ7 16 Stack 16 x 16 BSR 8 BSR <7:4> IR <7:0> 12 RAM Address Buffer Data RAM 17C766 902 x 8 and 17C762 678 x 8 Data Latch Instruction Decode Read/Write Decode for Registers Mapped in Data Space 8 x 8 mult
PIC17C762/766 BLOCK DIAGRAM
PORTA Q1, Q2, Q3, Q4 Clock Generator IR<16> Power-on Reset Watchdog Timer Chip_reset & Other Control Signals Test Mode Select Brown-out Reset OSC1, OSC2 VDD, VSS
WREG<8>
BITOP
MCLR, VPP
ALU
Test AVDD, AVSS
PRODH PRODL
Shifter
IR Latch <16> 8 8
16
FSR0 FSR1
Decode
ROM Latch <16>
8
Control Outputs
AD<15:0> PORTC, PORTD System Bus Interface ALE, WR, OE, PORTE Table Latch <16> Data Latch Program Memory (EPROM) 17C766 16K x 16, and 17C762 8K x 16 Address Latch 16
Literal
PCLATH<8>
Table Pointer<16>
Timer1
Timer3
USART2
PWM2
Capture1
Interrupt Module
SSP
10-bit A/D
Capture2
Capture3
Capture4
2000 Microchip Technology Inc.
DS30289B-page 13
PIC17C7XX
TABLE 3-1:
Name OSC1/CLKIN OSC2/CLKOUT
PINOUT DESCRIPTIONS
PIC17C75X DIP No. 47 48 PLCC No. 50 51 TQFP No. 39 40 PIC17C76X PLCC No. 62 63 QFP No. 49 50 I/O/P Type I O Buffer Type ST -- Description Oscillator input in Crystal/Resonator or RC Oscillator mode. External clock input in External Clock mode. Oscillator output. Connects to crystal or resonator in Crystal Oscillator mode. In RC Oscillator or External Clock modes, OSC2 pin outputs CLKOUT which has one fourth the frequency (FOSC/4) of OSC1 and denotes the instruction cycle rate. Master clear (RESET) input or Programming Voltage (VPP) input. This is the active low RESET input to the device. PORTA pins have individual differentiations that are listed in the following descriptions:
MCLR/VPP
15
16
7
20
9
I/P
ST
RA0/INT
56
60
48
72
58
I
ST
RA0 can also be selected as an external interrupt input. Interrupt can be configured to be on positive or negative edge. Input only pin. RA1 can also be selected as an external interrupt input and the interrupt can be configured to be on positive or negative edge. RA1 can also be selected to be the clock input to the Timer0 timer/counter. Input only pin. RA2 can also be used as the slave select input for the SPI or the clock input for the I2C bus. High voltage, high current, open drain port pin. RA3 can also be used as the data input for the SPI or the data for the I2C bus. High voltage, high current, open drain port pin. RA4 can also be selected as the USART1 (SCI) Asynchronous Receive or USART1 (SCI) Synchronous Data. Output available from USART only. RA5 can also be selected as the USART1 (SCI) Asynchronous Transmit or USART1 (SCI) Synchronous Clock. Output available from USART only. PORTB is a bi-directional I/O Port with software configurable weak pull-ups.
RA1/T0CKI
41
44
33
56
43
I
ST
RA2/SS/SCL
42
45
34
57
44
I/O(2)
ST
RA3/SDI/SDA
43
46
35
58
45
I/O(2)
ST
RA4/RX1/DT1
40
43
32
51
38
I/O(1)
ST
RA5/TX1/CK1
39
42
31
50
37
I/O(1)
ST
RB0/CAP1 RB1/CAP2 RB2/PWM1 RB3/PWM2 RB4/TCLK12 RB5/TCLK3 RB6/SCK RB7/SDO
55 54 50 53 52 51 44 45
59 58 54 57 56 55 47 48
47 46 42 45 44 43 36 37
71 70 66 69 68 67 59 60
57 56 52 55 54 53 46 47
I/O I/O I/O I/O I/O I/O I/O I/O
ST ST ST ST ST ST ST ST
RB0 can also be the Capture1 input pin. RB1 can also be the Capture2 input pin. RB2 can also be the PWM1 output pin. RB3 can also be the PWM2 output pin. RB4 can also be the external clock input to Timer1 and Timer2. RB5 can also be the external clock input to Timer3. RB6 can also be used as the master/slave clock for the SPI. RB7 can also be used as the data output for the SPI.
Legend: I = Input only; O = Output only; I/O = Input/Output; P = Power; -- = Not Used; TTL = TTL input; ST = Schmitt Trigger input Note 1: The output is only available by the peripheral operation. 2: Open drain input/output pin. Pin forced to input upon any device RESET.
DS30289B-page 14
2000 Microchip Technology Inc.
PIC17C7XX
TABLE 3-1:
Name
PINOUT DESCRIPTIONS (CONTINUED)
PIC17C75X DIP No. 2 63 62 61 60 58 58 57 10 9 8 7 6 5 4 3 11 PLCC No. 3 67 66 65 64 63 62 61 11 10 9 8 7 6 5 4 12 TQFP No. 58 55 54 53 52 51 50 49 2 1 64 63 62 61 60 59 3 PIC17C76X PLCC No. 3 83 82 81 80 79 78 77 15 14 9 8 7 6 5 4 16 QFP No. 72 69 68 67 66 65 64 63 4 3 78 77 76 75 74 73 5 I/O/P Type I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O I/O Buffer Type TTL TTL TTL TTL TTL TTL TTL TTL PORTD is a bi-directional I/O Port. TTL TTL TTL TTL TTL TTL TTL TTL PORTE is a bi-directional I/O Port. TTL In Microprocessor mode or Extended Microcontroller mode, RE0 is the Address Latch Enable (ALE) output. Address should be latched on the falling edge of ALE output. In Microprocessor or Extended Microcontroller mode, RE1 is the Output Enable (OE) control output (active low). In Microprocessor or Extended Microcontroller mode, RE2 is the Write Enable (WR) control output (active low). RE3 can also be the Capture4 input pin. PORTF is a bi-directional I/O Port. RF0 can also be analog input 4. RF1 can also be analog input 5. RF2 can also be analog input 6. RF3 can also be analog input 7. RF4 can also be analog input 8. RF5 can also be analog input 9. RF6 can also be analog input 10. RF7 can also be analog input 11. This is also the most significant byte (MSB) of the 16-bit system bus in Microprocessor mode or Extended Microcontroller mode. In multiplexed system bus configuration, these pins are address output as well as data input or output. Description PORTC is a bi-directional I/O Port.
RC0/AD0 RC1/AD1 RC2/AD2 RC3/AD3 RC4/AD4 RC5/AD5 RC6/AD6 RC7/AD7 RD0/AD8 RD1/AD9 RD2/AD10 RD3/AD11 RD4/AD12 RD5/AD13 RD6/AD14 RD7/AD15 RE0/ALE
This is also the least significant byte (LSB) of the 16-bit wide system bus in Microprocessor mode or Extended Microcontroller mode. In multiplexed system bus configuration, these pins are address output as well as data input or output.
RE1/OE
12
13
4
17
6
I/O
TTL
RE2/WR
13
14
5
18
7
I/O
TTL
RE3/CAP4 RF0/AN4 RF1/AN5 RF2/AN6 RF3/AN7 RF4/AN8 RF5/AN9 RF6/AN10 RF7/AN11
14 26 25 24 23 22 21 20 19
15 28 27 26 25 24 23 22 21
6 18 17 16 15 14 13 12 11
19 36 35 30 29 28 27 26 25
8 24 23 18 17 16 15 14 13
I/O I/O I/O I/O I/O I/O I/O I/O I/O
ST ST ST ST ST ST ST ST ST
Legend: I = Input only; O = Output only; I/O = Input/Output; P = Power; -- = Not Used; TTL = TTL input; ST = Schmitt Trigger input Note 1: The output is only available by the peripheral operation. 2: Open drain input/output pin. Pin forced to input upon any device RESET.
2000 Microchip Technology Inc.
DS30289B-page 15
PIC17C7XX
TABLE 3-1:
Name
PINOUT DESCRIPTIONS (CONTINUED)
PIC17C75X DIP No. 32 31 30 29 35 36 38 PLCC No. 34 33 32 31 38 39 41 TQFP No. 24 23 22 21 27 28 30 PIC17C76X PLCC No. 42 41 40 39 46 47 49 QFP No. 30 29 28 27 33 34 36 I/O/P Type I/O I/O I/O I/O I/O I/O I/O Buffer Type ST ST ST ST ST ST ST Description PORTG is a bi-directional I/O Port.
RG0/AN3 RG1/AN2 RG2/AN1/VREFRG3/AN0/VREF+ RG4/CAP3 RG5/PWM3 RG6/RX2/DT2
RG0 can also be analog input 3. RG1 can also be analog input 2. RG2 can also be analog input 1, or the ground reference voltage. RG3 can also be analog input 0, or the positive reference voltage. RG4 can also be the Capture3 input pin. RG5 can also be the PWM3 output pin. RG6 can also be selected as the USART2 (SCI) Asynchronous Receive or USART2 (SCI) Synchronous Data. RG7 can also be selected as the USART2 (SCI) Asynchronous Transmit or USART2 (SCI) Synchronous Clock. PORTH is a bi-directional I/O Port. PORTH is only available on the PIC17C76X devices.
RG7/TX2/CK2
37
40
29
48
35
I/O
ST
RH0 RH1 RH2 RH3 RH4/AN12 RH5/AN13 RH6/AN14 RH7/AN15
-- -- -- -- -- -- -- --
-- -- -- -- -- -- -- --
-- -- -- -- -- -- -- --
10 11 12 13 31 32 33 34
79 80 1 2 19 20 21 22
I/O I/O I/O I/O I/O I/O I/O I/O
ST ST ST ST ST ST ST ST
RH4 can also be analog input 12. RH5 can also be analog input 13. RH6 can also be analog input 14. RH7 can also be analog input 15. PORTJ is a bi-directional I/O Port. PORTJ is only available on the PIC17C76X devices.
RJ0 RJ1 RJ2 RJ3 RJ4 RJ5 RJ6 RJ7 TEST VSS VDD AVSS AVDD NC
-- -- -- -- -- -- -- -- 16
-- -- -- -- -- -- -- -- 17
-- -- -- -- -- -- -- -- 8
52 53 54 55 73 74 75 76 21
39 40 41 42 59 60 61 62 10
I/O I/O I/O I/O I/O I/O I/O I/O I P P P P
ST ST ST ST ST ST ST ST ST Test mode selection control input. Always tie to VSS for normal operation. Ground reference for logic and I/O pins. Positive supply for logic and I/O pins. Ground reference for A/D converter. This pin MUST be at the same potential as VSS. Positive supply for A/D converter. This pin MUST be at the same potential as VDD. No Connect. Leave these pins unconnected.
17, 33, 19, 36, 9, 25, 23, 44, 11, 31, 49, 64 53, 68 41, 56 65, 84 51, 70 1, 18, 2, 20, 10, 26, 24, 45, 12, 32, 34, 46 37, 49, 38, 57 61, 2 48, 71 28 27 -- 30 29 1, 18, 35, 52 20 19 -- 38 37 1, 22, 43, 64 26 25 --
Legend: I = Input only; O = Output only; I/O = Input/Output; P = Power; -- = Not Used; TTL = TTL input; ST = Schmitt Trigger input Note 1: The output is only available by the peripheral operation. 2: Open drain input/output pin. Pin forced to input upon any device RESET.
DS30289B-page 16
2000 Microchip Technology Inc.
PIC17C7XX
4.0 ON-CHIP OSCILLATOR CIRCUIT
4.1.2 CRYSTAL OSCILLATOR/CERAMIC RESONATORS
The internal oscillator circuit is used to generate the device clock. Four device clock periods generate an internal instruction clock (TCY). There are four modes that the oscillator can operate in. They are selected by the device configuration bits during device programming. These modes are: * LF * XT * EC * RC Low Frequency (FOSC 2 MHz) Standard Crystal/Resonator Frequency (2 MHz FOSC 33 MHz) External Clock Input (Default oscillator configuration) External Resistor/Capacitor (FOSC 4 MHz)
In XT or LF modes, a crystal or ceramic resonator is connected to the OSC1/CLKIN and OSC2/CLKOUT pins to establish oscillation (Figure 4-2). The PIC17CXXX oscillator design requires the use of a parallel cut crystal. Use of a series cut crystal may give a frequency out of the crystal manufacturers specifications. For frequencies above 24 MHz, it is common for the crystal to be an overtone mode crystal. Use of overtone mode crystals require a tank circuit to attenuate the gain at the fundamental frequency. Figure 4-3 shows an example circuit.
4.1.3
OSCILLATOR/RESONATOR START-UP
There are two timers that offer necessary delays on power-up. One is the Oscillator Start-up Timer (OST), intended to keep the chip in RESET until the crystal oscillator is stable. The other is the Power-up Timer (PWRT), which provides a fixed delay of 96 ms (nominal) on POR and BOR. The PWRT is designed to keep the part in RESET while the power supply stabilizes. With these two timers on-chip, most applications need no external RESET circuitry. SLEEP mode is designed to offer a very low current power-down mode. The user can wake from SLEEP through external RESET, Watchdog Timer Reset, or through an interrupt. Several oscillator options are made available to allow the part to better fit the application. The RC oscillator option saves system cost while the LF crystal option saves power. Configuration bits are used to select various options.
As the device voltage increases from Vss, the oscillator will start its oscillations. The time required for the oscillator to start oscillating depends on many factors. These include: * * * * * * Crystal/resonator frequency Capacitor values used (C1 and C2) Device VDD rise time System temperature Series resistor value (and type) if used Oscillator mode selection of device (which selects the gain of the internal oscillator inverter)
Figure 4-1 shows an example of a typical oscillator/ resonator start-up. The peak-to-peak voltage of the oscillator waveform can be quite low (less than 50% of device VDD) when the waveform is centered at VDD/2 (refer to parameter #D033 and parameter #D043 in the electrical specification section).
4.1
4.1.1
Oscillator Configurations
OSCILLATOR TYPES
FIGURE 4-1:
OSCILLATOR/ RESONATOR START-UP CHARACTERISTICS
The PIC17CXXX can be operated in four different oscillator modes. The user can program two configuration bits (FOSC1:FOSC0) to select one of these four modes: * * * * LF XT EC RC Low Power Crystal Crystal/Resonator External Clock Input Resistor/Capacitor
The main difference between the LF and XT modes is the gain of the internal inverter of the oscillator circuit, which allows the different frequency ranges. For more details on the device configuration bits, see Section 17.0.
Crystal Start-up Time
VDD
Time
2000 Microchip Technology Inc.
DS30289B-page 17
PIC17C7XX
FIGURE 4-2: CRYSTAL OR CERAMIC RESONATOR OPERATION (XT OR LF OSC CONFIGURATION)
OSC1 C1 XTAL OSC2 (Note 1) C2 PIC17CXXX See Table 4-1 and Table 4-2 for recommended values of C1 and C2. Note 1: A series resistor (Rs) may be required for AT strip cut crystals. To internal logic C3 0.1 F L1 PIC17CXXX RF SLEEP C2 OSC2 SLEEP
FIGURE 4-3:
CRYSTAL OPERATION, OVERTONE CRYSTALS (XT OSC CONFIGURATION)
OSC1
C1
To filter the fundamental frequency: 1= 2 L1*C2 (2f) Where f = tank circuit resonant frequency. This should be midway between the fundamental and the 3rd overtone frequencies of the crystal. C3 blocks DC current to ground.
TABLE 4-1:
CAPACITOR SELECTION FOR CERAMIC RESONATORS
Resonator Frequency 455 kHz 2.0 MHz 4.0 MHz 8.0 MHz 16.0 MHz Capacitor Range C1 = C2(1) 15 - 68 pF 10 - 33 pF 22 - 68 pF 33 - 100 pF 33 - 100 pF
TABLE 4-2:
Oscillator Type LF XT
CAPACITOR SELECTION FOR CRYSTAL OSCILLATOR
Freq C1(2) 100-150 pF 10-68 pF 10-68 pF 47-100 pF 15-68 pF 15-47 pF 15-47 pF 15-47 pF 10-47 pF C2(2) 100-150 pF 10-68 pF 10-68 pF 47-100 pF 15-68 pF 15-47 pF 15-47 pF 15-47 pF 10-47 pF
Osc Type LF
32 kHz 1 MHz 2 MHz 2 MHz 4 MHz 8 MHz 16 MHz 24 MHz(1) 32 MHz(1)
Higher capacitance increases the stability of the oscillator, but also increases the start-up time. These values are for design guidance only. Since each resonator has its own characteristics, the user should consult the resonator manufacturer for appropriate values of external components. Note 1: These values include all board capacitances on this pin. Actual capacitor value depends on board capacitance. Resonators Used: 455 kHz 2.0 MHz 4.0 MHz 8.0 MHz 16.0 MHz Panasonic EFO-A455K04B Murata Erie CSA2.00MG Murata Erie CSA4.00MG Murata Erie CSA8.00MT Murata Erie CSA16.00MX 0.3% 0.5% 0.5% 0.5% 0.5%
XT
Resonators used did not have built-in capacitors.
Higher capacitance increases the stability of the oscillator, but also increases the start-up time and the oscillator current. These values are for design guidance only. RS may be required in XT mode to avoid overdriving the crystals with low drive level specification. Since each crystal has its own characteristics, the user should consult the crystal manufacturer for appropriate values for external components. Note 1: Overtone crystals are used at 24 MHz and higher. The circuit in Figure 4-3 should be used to select the desired harmonic frequency. 2: These values include all board capacitances on this pin. Actual capacitor value depends on board capacitance. Crystals Used: 32.768 kHz 1.0 MHz 2.0 MHz 4.0 MHz 8.0 MHz 16.0 MHz 25 MHz 32 MHz Epson C-001R32.768K-A ECS-10-13-1 ECS-20-20-1 ECS-40-20-1 ECS ECS-80-S-4 ECS-80-18-1 ECS-160-20-1 CTS CTS25M CRYSTEK HF-2 20 PPM 50 PPM 50 PPM 50 PPM 50 PPM 50 PPM 50 PPM 50 PPM
DS30289B-page 18
2000 Microchip Technology Inc.
PIC17C7XX
4.1.4 EXTERNAL CLOCK OSCILLATOR FIGURE 4-5:
In the EC oscillator mode, the OSC1 input can be driven by CMOS drivers. In this mode, the OSC1/ CLKIN pin is hi-impedance and the OSC2/CLKOUT pin is the CLKOUT output (4 TOSC).
EXTERNAL PARALLEL RESONANT CRYSTAL OSCILLATOR CIRCUIT
To Other Devices
+5V 10 k 4.7 k 74AS04
FIGURE 4-4:
EXTERNAL CLOCK INPUT OPERATION (EC OSC CONFIGURATION)
OSC1 PIC17CXXX OSC2 10k
74AS04
PIC17CXXX OSC1
Clock from ext. system CLKOUT (FOSC/4)
10 k XTAL
20 pF
20 pF
4.1.5
EXTERNAL CRYSTAL OSCILLATOR CIRCUIT
Either a prepackaged oscillator can be used, or a simple oscillator circuit with TTL gates can be built. Prepackaged oscillators provide a wide operating range and better stability. A well designed crystal oscillator will provide good performance with TTL gates. Two types of crystal oscillator circuits can be used: one with series resonance, or one with parallel resonance. Figure 4-5 shows implementation of a parallel resonant oscillator circuit. The circuit is designed to use the fundamental frequency of the crystal. The 74AS04 inverter performs the 180-degree phase shift that a parallel oscillator requires. The 4.7 k resistor provides the negative feedback for stability. The 10 k potentiometer biases the 74AS04 in the linear region. This could be used for external oscillator designs.
Figure 4-6 shows a series resonant oscillator circuit. This circuit is also designed to use the fundamental frequency of the crystal. The inverter performs a 180degree phase shift in a series resonant oscillator circuit. The 330 resistors provide the negative feedback to bias the inverters in their linear region.
FIGURE 4-6:
EXTERNAL SERIES RESONANT CRYSTAL OSCILLATOR CIRCUIT
To Other Devices 74AS04 PIC17CXXX OSC1
330 74AS04 0.1 F XTAL
330 74AS04
2000 Microchip Technology Inc.
DS30289B-page 19
PIC17C7XX
4.1.6 RC OSCILLATOR FIGURE 4-7:
VDD REXT OSC1 PIC17CXXX Internal Clock
RC OSCILLATOR MODE
For timing insensitive applications, the RC device option offers additional cost savings. RC oscillator frequency is a function of the supply voltage, the resistor (REXT) and capacitor (CEXT) values, and the operating temperature. In addition to this, oscillator frequency will vary from unit to unit due to normal process parameter variation. Furthermore, the difference in lead frame capacitance between package types will also affect oscillation frequency, especially for low CEXT values. The user also needs to take into account variation due to tolerance of external R and C components used. Figure 4-7 shows how the R/C combination is connected to the PIC17CXXX. For REXT values below 2.2 k, the oscillator operation may become unstable, or stop completely. For very high REXT values (e.g. 1 M), the oscillator becomes sensitive to noise, humidity and leakage. Thus, we recommend to keep REXT between 3 k and 100 k. Although the oscillator will operate with no external capacitor (CEXT = 0 pF), we recommend using values above 20 pF for noise and stability reasons. With little or no external capacitance, oscillation frequency can vary dramatically due to changes in external capacitances, such as PCB trace capacitance or package lead frame capacitance. See Section 21.0 for RC frequency variation from part to part due to normal process variation. The variation is larger for larger R (since leakage current variation will affect RC frequency more for large R) and for smaller C (since variation of input capacitance will affect RC frequency more). See Section 21.0 for variation of oscillator frequency due to VDD for given REXT/CEXT values, as well as frequency variation due to operating temperature for given R, C, and VDD values. The oscillator frequency, divided by 4, is available on the OSC2/CLKOUT pin and can be used for test purposes or to synchronize other logic (see Figure 4-8 for waveform).
CEXT VSS FOSC/4 OSC2/CLKOUT
4.1.6.1
RC Start-up
As the device voltage increases, the RC will immediately start its oscillations once the pin voltage levels meet the input threshold specifications (parameter #D032 and parameter #D042 in the electrical specification section). The time required for the RC to start oscillating depends on many factors. These include: * * * * Resistor value used Capacitor value used Device VDD rise time System temperature
DS30289B-page 20
2000 Microchip Technology Inc.
PIC17C7XX
4.2 Clocking Scheme/Instruction Cycle 4.3 Instruction Flow/Pipelining
An "Instruction Cycle" consists of four Q cycles (Q1, Q2, Q3 and Q4). The instruction fetch and execute are pipelined such that fetch takes one instruction cycle, while decode and execute takes another instruction cycle. However, due to the pipelining, each instruction effectively executes in one cycle. If an instruction causes the program counter to change (e.g. GOTO), then two cycles are required to complete the instruction (Example 4-1). A fetch cycle begins with the program counter incrementing in Q1. In the execution cycle, the fetched instruction is latched into the "Instruction Register (IR)" in cycle Q1. This instruction is then decoded and executed during the Q2, Q3 and Q4 cycles. Data memory is read during Q2 (operand read) and written during Q4 (destination write).
The clock input (from OSC1) is internally divided by four to generate four non-overlapping quadrature clocks, namely Q1, Q2, Q3 and Q4. Internally, the program counter (PC) is incremented every Q1 and the instruction is fetched from the program memory and latched into the instruction register in Q4. The instruction is decoded and executed during the following Q1 through Q4. The clocks and instruction execution flow are shown in Figure 4-8.
FIGURE 4-8:
OSC1 Q1 Q2 Q3 Q4 PC OSC2/CLKOUT (RC mode)
CLOCK/INSTRUCTION CYCLE
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Internal Phase Clock
PC
PC+1
PC+2
Fetch INST (PC) Execute INST (PC-1)
Fetch INST (PC+1) Execute INST (PC)
Fetch INST (PC+2) Execute INST (PC+1)
EXAMPLE 4-1:
INSTRUCTION PIPELINE FLOW
TCY0 TCY1 Execute 1 Fetch 2 Execute 2 Fetch 3 Execute 3 Fetch 4 Flush Fetch SUB_1 Execute SUB_1 TCY2 TCY3 TCY4 TCY5
1. MOVLW 55h 2. MOVWF PORTB 3. CALL SUB_1 4. BSF
Fetch 1
PORTA, BIT3 (Forced NOP)
5. Instruction @ address SUB_1
All instructions are single cycle, except for any program branches. These take two cycles since the fetched instruction is "flushed" from the pipeline, while the new instruction is being fetched and then executed.
2000 Microchip Technology Inc.
DS30289B-page 21
PIC17C7XX
NOTES:
DS30289B-page 22
2000 Microchip Technology Inc.
PIC17C7XX
5.0 RESET
The PIC17CXXX differentiates between various kinds of RESET: * * * * Power-on Reset (POR) Brown-out Reset MCLR Reset WDT Reset When the device enters the "RESET state", the Data Direction registers (DDR) are forced set, which will make the I/O hi-impedance inputs. The RESET state of some peripheral modules may force the I/O to other operations, such as analog inputs or the system bus. Note: While the device is in a RESET state, the internal phase clock is held in the Q1 state. Any processor mode that allows external execution will force the RE0/ALE pin as a low output and the RE1/OE and RE2/WR pins as high outputs.
Some registers are not affected in any RESET condition, their status is unknown on POR and unchanged in any other RESET. Most other registers are forced to a "RESET state". The TO and PD bits are set or cleared differently in different RESET situations, as indicated in Table 5-3. These bits, in conjunction with the POR and BOR bits, are used in software to determine the nature of the RESET. See Table 5-4 for a full description of the RESET states of all registers.
A simplified block diagram of the On-Chip Reset Circuit is shown in Figure 5-1.
FIGURE 5-1:
SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
External Reset
MCLR BOR Module WDT Module VDD Rise Detect VDD OST/PWRT Chip_Reset OST 10-bit Ripple Counter OSC1 On-chip RC OSC PWRT 10-bit Ripple Counter Enable PWRT R Q Brown-out Reset WDT Time_Out Reset Power_On_Reset S
Enable OST
(Enable the PWRT timer only during POR or BOR) (If PWRT is invoked, or a Wake-up from SLEEP and OSC type is XT or LF)
This RC oscillator is shared with the WDT when not in a power-up sequence.
2000 Microchip Technology Inc.
DS30289B-page 23
PIC17C7XX
5.1 Power-on Reset (POR), Power-up Timer (PWRT), Oscillator Start-up Timer (OST) and Brown-out Reset (BOR)
POWER-ON RESET (POR) 5.1.2 POWER-UP TIMER (PWRT)
The Power-up Timer provides a fixed 96 ms time-out (nominal) on power-up. This occurs from the rising edge of the internal POR signal if VDD and MCLR are tied, or after the first rising edge of MCLR (detected high). The Power-up Timer operates on an internal RC oscillator. The chip is kept in RESET as long as the PWRT is active. In most cases, the PWRT delay allows VDD to rise to an acceptable level. The power-up time delay will vary from chip to chip and with VDD and temperature. See DC parameters for details.
5.1.1
The Power-on Reset circuit holds the device in RESET until VDD is above the trip point (in the range of 1.4V 2.3V). The devices produce an internal RESET for both rising and falling VDD. To take advantage of the POR, just tie the MCLR/VPP pin directly (or through a resistor) to VDD. This will eliminate external RC components usually needed to create Power-on Reset. A minimum rise time for VDD is required. See Electrical Specifications for details. Figure 5-2 and Figure 5-3 show two possible POR circuits.
5.1.3
OSCILLATOR START-UP TIMER (OST)
FIGURE 5-2:
VDD
USING ON-CHIP POR
The Oscillator Start-up Timer (OST) provides a 1024 oscillator cycle (1024TOSC) delay whenever the PWRT is invoked, or a wake-up from SLEEP event occurs in XT or LF mode. The PWRT and OST operate in parallel. The OST counts the oscillator pulses on the OSC1/ CLKIN pin. The counter only starts incrementing after the amplitude of the signal reaches the oscillator input thresholds. This delay allows the crystal oscillator or resonator to stabilize before the device exits RESET. The length of the time-out is a function of the crystal/ resonator frequency. Figure 5-4 shows the operation of the OST circuit. In this figure, the oscillator is of such a low frequency that although enabled simultaneously, the OST does not time-out until after the Power-up Timer time-out.
VDD MCLR
PIC17CXXX
FIGURE 5-3:
EXTERNAL POWER-ON RESET CIRCUIT (FOR SLOW VDD POWER-UP)
VDD
FIGURE 5-4:
OSCILLATOR START-UP TIME (LOW FREQUENCY)
POR or BOR Trip Point
VDD D
VDD R R1 MCLR C PIC17CXXX MCLR OSC2 TOSC1 TOST Note 1: An external Power-on Reset circuit is required only if VDD power-up time is too slow. The diode D helps discharge the capacitor quickly when VDD powers down. 2: R < 40 k is recommended to ensure that the voltage drop across R does not exceed 0.2V (max. leakage current spec. on the MCLR/ VPP pin is 5 A). A larger voltage drop will degrade VIH level on the MCLR/VPP pin. 3: R1 = 100 to 1 k will limit any current flowing into MCLR from external capacitor C in the event of MCLR/VPP pin breakdown due to Electrostatic Discharge (ESD) or Electrical Overstress (EOS). OST TIME_OUT PWRT TIME_OUT TPWRT INTERNAL RESET This figure shows in greater detail the timings involved with the oscillator start-up timer. In this example, the low frequency crystal start-up time is larger than power-up time (TPWRT). TOSC1 = time for the crystal oscillator to react to an oscillation level detectable by the Oscillator Start-up Timer (OST). TOST = 1024TOSC.
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PIC17C7XX
5.1.4 TIME-OUT SEQUENCE
On power-up, the time-out sequence is as follows: First, the internal POR signal goes high when the POR trip point is reached. If MCLR is high, then both the OST and PWRT timers start. In general, the PWRT time-out is longer, except with low frequency crystals/resonators. The total time-out also varies based on oscillator configuration. Table 5-1 shows the times that are associated with the oscillator configuration. Figure 5-5 and Figure 56 display these time-out sequences. If the device voltage is not within electrical specification at the end of a time-out, the MCLR/VPP pin must be held low until the voltage is within the device specification. The use of an external RC delay is sufficient for many of these applications. The time-out sequence begins from the first rising edge of MCLR. Table 5-3 shows the RESET conditions for some special registers, while Table 5-4 shows the initialization conditions for all the registers.
TABLE 5-1:
TIME-OUT IN VARIOUS SITUATIONS
POR, BOR Greater of: 96 ms or 1024TOSC Greater of: 96 ms or 1024TOSC Wake-up from SLEEP 1024TOSC -- MCLR Reset -- --
Oscillator Configuration XT, LF EC, RC
TABLE 5-2:
POR
0 1 1 1 1 1 0 0 x
STATUS BITS AND THEIR SIGNIFICANCE
TO
1 1 0 0 1 1 0 x 1
BOR(1)
0 1 1 1 1 0 0 0 x
PD
1 0 1 0 1 1 x 0 1
Event Power-on Reset MCLR Reset during SLEEP or interrupt wake-up from SLEEP WDT Reset during normal operation WDT Wake-up during SLEEP MCLR Reset during normal operation Brown-out Reset Illegal, TO is set on POR Illegal, PD is set on POR CLRWDT instruction executed
Note 1: When BODEN is enabled, else the BOR status bit is unknown.
TABLE 5-3:
RESET CONDITION FOR THE PROGRAM COUNTER AND THE CPUSTA REGISTER
Event PCH:PCL 0000h 0000h 0000h 0000h 0000h 0000h PC + 1 PC + 1(1) GLINTD is clear CPUSTA(4) --11 1100 --11 1110 --11 1111 --11 1011 --11 0111 --11 0011 --11 1011 --10 1011 OST Active Yes Yes No Yes(2) No Yes(2) Yes(2) Yes(2)
Power-on Reset Brown-out Reset MCLR Reset during normal operation MCLR Reset during SLEEP WDT Reset during normal operation WDT Reset during SLEEP(3) Interrupt Wake-up from SLEEP GLINTD is set
Legend: u = unchanged, x = unknown, - = unimplemented, read as '0' Note 1: On wake-up, this instruction is executed. The instruction at the appropriate interrupt vector is fetched and then executed. 2: The OST is only active (on wake-up) when the oscillator is configured for XT or LF modes. 3: The Program Counter = 0; that is, the device branches to the RESET vector and places SFRs in WDT Reset states. This is different from the mid-range devices. 4: When BODEN is enabled, else the BOR status bit is unknown.
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PIC17C7XX
In Figure 5-5, Figure 5-6 and Figure 5-7, the TPWRT timer time-out is greater then the TOST timer time-out, as would be the case in higher frequency crystals. For lower frequency crystals (i.e., 32 kHz), TOST may be greater.
FIGURE 5-5:
TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD)
VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
FIGURE 5-6:
VDD MCLR INTERNAL POR
TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD)
TPWRT PWRT TIME-OUT TOST
OST TIME-OUT
INTERNAL RESET
FIGURE 5-7:
SLOW RISE TIME (MCLR TIED TO VDD)
Minimum VDD Operating Voltage
5V VDD MCLR 0V 1V
INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET
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PIC17C7XX
TABLE 5-4:
Register Unbanked INDF0 FSR0 PCL PCLATH ALUSTA T0STA CPUSTA INTSTA INDF1 FSR1 WREG TMR0L TMR0H TBLPTRL TBLPTRH BSR Bank 0 PORTA(4,6) DDRB PORTB(4) RCSTA1 RCREG1 TXSTA1 TXREG1 SPBRG1 10h 11h 12h 13h 14h 15h 16h 17h 0-xx 11xx 1111 1111 xxxx xxxx 0000 -00x xxxx xxxx 0000 --1x xxxx xxxx 0000 0000 0-uu 11uu 1111 1111 uuuu uuuu 0000 -00u uuuu uuuu 0000 --1u uuuu uuuu 0000 0000 u-uu uuuu uuuu uuuu uuuu uuuu uuuu -uuu uuuu uuuu uuuu --uu uuuu uuuu uuuu uuuu
(3)
INITIALIZATION CONDITIONS FOR SPECIAL FUNCTION REGISTERS
Address Power-on Reset Brown-out Reset N/A xxxx xxxx 0000h 0000 0000 1111 xxxx 0000 000--11 11qq 0000 0000 N/A xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 0000 0000 0000 0000 0000 0000 MCLR Reset WDT Reset N/A uuuu uuuu 0000h uuuu uuuu 1111 uuuu 0000 000--11 qquu 0000 0000 N/A uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu 0000 0000 0000 0000 0000 0000 Wake-up from SLEEP through Interrupt N/A uuuu uuuu PC + 1(2) uuuu uuuu 1111 uuuu 0000 000--uu qquu uuuu uuuu(1) N/A uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu
00h 01h 02h 03h 04h 05h 06h 07h 08h 09h 0Ah 0Bh 0Ch 0Dh 0Eh 0Fh
Legend: u = unchanged, x = unknown, - = unimplemented, read as '0', q = value depends on condition Note 1: One or more bits in INTSTA, PIR1, PIR2 will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GLINTD bit is cleared, the PC is loaded with the interrupt vector. 3: See Table 5-3 for RESET value of specific condition. 4: This is the value that will be in the port output latch. 5: When the device is configured for Microprocessor or Extended Microcontroller mode, the operation of this port does not rely on these registers. 6: On any device RESET, these pins are configured as inputs.
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PIC17C7XX
TABLE 5-4:
Register Bank 1 DDRC(5) PORTC
(4,5)
INITIALIZATION CONDITIONS FOR SPECIAL FUNCTION REGISTERS (CONTINUED)
Address Power-on Reset Brown-out Reset MCLR Reset WDT Reset Wake-up from SLEEP through Interrupt
10h 11h 12h 13h 14h 15h 16h 17h 10h 11h 12h 13h 14h 15h 16h 17h 10h 11h 12h 13h 14h 15h 16h 17h
1111 1111 xxxx xxxx 1111 1111 xxxx xxxx ---- 1111 ---- xxxx x000 0010 0000 0000
1111 1111 uuuu uuuu 1111 1111 uuuu uuuu ---- 1111 ---- uuuu u000 0010 0000 0000
uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu ---- uuuu ---- uuuu uuuu uuuu(1) uuuu uuuu
DDRD(5) PORTD(4,5) DDRE(5) PORTE(4,5) PIR1 PIE1 Bank 2 TMR1 TMR2 TMR3L TMR3H PR1 PR2 PR3/CA1L PR3/CA1H Bank 3 PW1DCL PW2DCL PW1DCH PW2DCH CA2L CA2H TCON1 TCON2
xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx
uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu
uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu
xx-- ---xx0- ---xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx 0000 0000 0000 0000
uu-- ---uu0- ---uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu 0000 0000 0000 0000
uu-- ---uuu- ---uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu
Legend: u = unchanged, x = unknown, - = unimplemented, read as '0', q = value depends on condition Note 1: One or more bits in INTSTA, PIR1, PIR2 will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GLINTD bit is cleared, the PC is loaded with the interrupt vector. 3: See Table 5-3 for RESET value of specific condition. 4: This is the value that will be in the port output latch. 5: When the device is configured for Microprocessor or Extended Microcontroller mode, the operation of this port does not rely on these registers. 6: On any device RESET, these pins are configured as inputs.
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PIC17C7XX
TABLE 5-4:
Register Bank 4 PIR2 PIE2
Unimplemented
INITIALIZATION CONDITIONS FOR SPECIAL FUNCTION REGISTERS (CONTINUED)
Address Power-on Reset Brown-out Reset MCLR Reset WDT Reset Wake-up from SLEEP through Interrupt
10h 11h 12h 13h 14h 15h 16h 17h 10h
(4)
000- 0010 000- 0000 ---- ---0000 -00x xxxx xxxx 0000 --1x xxxx xxxx 0000 0000
000- 0010 000- 0000 ---- ---0000 -00u uuuu uuuu 0000 --1u uuuu uuuu 0000 0000
uuu- uuuu(1) uuu- uuuu ---- ---uuuu -uuu uuuu uuuu uuuu --uu uuuu uuuu uuuu uuuu
RCSTA2 RCREG2 TXSTA2 TXREG2 SPBRG2 Bank 5 DDRF PORTF DDRG PORTG(4) ADCON0 ADCON1 ADRESL ADRESH Bank 6 SSPADD SSPCON1 SSPCON2 SSPSTAT SSPBUF
Unimplemented Unimplemented Unimplemented
1111 1111 0000 0000 1111 1111 xxxx 0000 0000 -0-0 000- 0000 xxxx xxxx xxxx xxxx
1111 1111 0000 0000 1111 1111 uuuu 0000 0000 -0-0 000- 0000 uuuu uuuu uuuu uuuu
uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu
11h 12h 13h 14h 15h 16h 17h 10h 11h 12h 13h 14h 15h 16h 17h
0000 0000 0000 0000 0000 0000 0000 0000 xxxx xxxx ---- ------- ------- ----
0000 0000 0000 0000 0000 0000 0000 0000 uuuu uuuu ---- ------- ------- ----
uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu ---- ------- ------- ----
Legend: u = unchanged, x = unknown, - = unimplemented, read as '0', q = value depends on condition Note 1: One or more bits in INTSTA, PIR1, PIR2 will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GLINTD bit is cleared, the PC is loaded with the interrupt vector. 3: See Table 5-3 for RESET value of specific condition. 4: This is the value that will be in the port output latch. 5: When the device is configured for Microprocessor or Extended Microcontroller mode, the operation of this port does not rely on these registers. 6: On any device RESET, these pins are configured as inputs.
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DS30289B-page 29
PIC17C7XX
TABLE 5-4:
Register Bank 7 PW3DCL PW3DCH CA3L CA3H CA4L CA4H TCON3
Unimplemented
INITIALIZATION CONDITIONS FOR SPECIAL FUNCTION REGISTERS (CONTINUED)
Address Power-on Reset Brown-out Reset MCLR Reset WDT Reset Wake-up from SLEEP through Interrupt
10h 11h 12h 13h 14h 15h 16h 17h 10h
xx0- ---xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx -000 0000 ---- ----
uu0- ---uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu -000 0000 ---- ----
uuu- ---uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu -uuu uuuu ---- ----
Bank 8 DDRH PORTH DDRJ PORTJ
(4) (4)
1111 1111 xxxx xxxx 1111 1111 xxxx xxxx
1111 1111 uuuu uuuu 1111 1111 uuuu uuuu
uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu
11h 12h 13h
Unbanked PRODL PRODH 18h 19h xxxx xxxx xxxx xxxx uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu
Legend: u = unchanged, x = unknown, - = unimplemented, read as '0', q = value depends on condition Note 1: One or more bits in INTSTA, PIR1, PIR2 will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GLINTD bit is cleared, the PC is loaded with the interrupt vector. 3: See Table 5-3 for RESET value of specific condition. 4: This is the value that will be in the port output latch. 5: When the device is configured for Microprocessor or Extended Microcontroller mode, the operation of this port does not rely on these registers. 6: On any device RESET, these pins are configured as inputs.
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PIC17C7XX
5.1.5 BROWN-OUT RESET (BOR)
PIC17C7XX devices have on-chip Brown-out Reset circuitry. This circuitry places the device into a RESET when the device voltage falls below a trip point (BVDD). This ensures that the device does not continue program execution outside the valid operation range of the device. Brown-out Resets are typically used in AC line applications, or large battery applications, where large loads may be switched in (such as automotive). Note: Before using the on-chip Brown-out for a voltage supervisory function, please review the electrical specifications to ensure that they meet your requirements. that may be implemented. Each needs to be evaluated to determine if they match the requirements of the application.
FIGURE 5-8:
VDD
EXTERNAL BROWN-OUT PROTECTION CIRCUIT 1
VDD
33k 10k 40 k
MCLR
PIC17CXXX
The BODEN configuration bit can disable (if clear/ programmed), or enable (if set) the Brown-out Reset circuitry. If VDD falls below BVDD (typically 4.0 V, paramter #D005 in electrical specification section), for greater than parameter #35, the Brown-out situation will reset the chip. A RESET is not guaranteed to occur if VDD falls below BVDD for less than paramter #35. The chip will remain in Brown-out Reset until VDD rises above BVDD. The Power-up Timer and Oscillator Startup Timer will then be invoked. This will keep the chip in RESET the greater of 96 ms and 1024 TOSC. If VDD drops below BVDD while the Power-up Timer/Oscillator Start-up Timer is running, the chip will go back into a Brown-out Reset. The Power-up Timer/Oscillator Startup Timer will be initialized. Once VDD rises above BVDD, the Power-up Timer/Oscillator Start-up Timer will start their time delays. Figure 5-10 shows typical Brown-out situations. In some applications, the Brown-out Reset trip point of the device may not be at the desired level. Figure 5-8 and Figure 5-9 are two examples of external circuitry
This circuit will activate RESET when VDD goes below (Vz + 0.7V) where Vz = Zener voltage.
FIGURE 5-9:
VDD
EXTERNAL BROWN-OUT PROTECTION CIRCUIT 2
VDD
R1 Q1 MCLR R2 40 k
PIC17CXXX
This brown-out circuit is less expensive, albeit less accurate. Transistor Q1 turns off when VDD is below a certain level such that:
VDD *
R1 R1 + R2
= 0.7V
FIGURE 5-10:
VDD
BROWN-OUT SITUATIONS
BVDD Max. BVDD Min. Greater of 96 ms and 1024 TOSC BVDD Max. BVDD Min. < 96 ms Greater of 96 ms and 1024 TOSC BVDD Max. BVDD Min. Greater of 96 ms and 1024 TOSC
Internal RESET VDD
Internal RESET VDD
Internal RESET
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NOTES:
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PIC17C7XX
6.0
* * * * * * * * * * * * * * * * * *
INTERRUPTS
PIC17C7XX devices have 18 sources of interrupt: External interrupt from the RA0/INT pin Change on RB7:RB0 pins TMR0 Overflow TMR1 Overflow TMR2 Overflow TMR3 Overflow USART1 Transmit buffer empty USART1 Receive buffer full USART2 Transmit buffer empty USART2 Receive buffer full SSP Interrupt SSP I2C bus collision interrupt A/D conversion complete Capture1 Capture2 Capture3 Capture4 T0CKI edge occurred
When an interrupt is responded to, the GLINTD bit is automatically set to disable any further interrupts, the return address is pushed onto the stack and the PC is loaded with the interrupt vector address. There are four interrupt vectors. Each vector address is for a specific interrupt source (except the peripheral interrupts, which all vector to the same address). These sources are: * * * * External interrupt from the RA0/INT pin TMR0 Overflow T0CKI edge occurred Any peripheral interrupt
When program execution vectors to one of these interrupt vector addresses (except for the peripheral interrupts), the interrupt flag bit is automatically cleared. Vectoring to the peripheral interrupt vector address does not automatically clear the source of the interrupt. In the peripheral Interrupt Service Routine, the source(s) of the interrupt can be determined by testing the interrupt flag bits. The interrupt flag bit(s) must be cleared in software before re-enabling interrupts to avoid infinite interrupt requests. When an interrupt condition is met, that individual interrupt flag bit will be set, regardless of the status of its corresponding mask bit or the GLINTD bit. For external interrupt events, there will be an interrupt latency. For two-cycle instructions, the latency could be one instruction cycle longer. The "return from interrupt" instruction, RETFIE, can be used to mark the end of the Interrupt Service Routine. When this instruction is executed, the stack is "POPed" and the GLINTD bit is cleared (to re-enable interrupts).
There are six registers used in the control and status of interrupts. These are: * * * * * * CPUSTA INTSTA PIE1 PIR1 PIE2 PIR2
The CPUSTA register contains the GLINTD bit. This is the Global Interrupt Disable bit. When this bit is set, all interrupts are disabled. This bit is part of the controller core functionality and is described in the Section 6.4.
FIGURE 6-1:
RBIF RBIE
INTERRUPT LOGIC
TMR3IF TMR3IE
PIR1/PIE1
TMR2IF TMR2IE TMR1IF TMR1IE CA2IF CA2IE CA1IF CA1IE TX1IF TX1IE RC1IF RC1IE SSPIF SSPIE BCLIF BCLIE
INTSTA
T0IF T0IE INTF INTE T0CKIF T0CKIE PEIF PEIE GLINTD (CPUSTA<4>) Wake-up (If in SLEEP mode) or terminate long write
Interrupt to CPU
PIR2/PIE2
ADIF ADIE CA4IF CA4IE CA3IF CA3IE TX2IF TX2IE RC2IF RC2IE
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PIC17C7XX
6.1 Interrupt Status Register (INTSTA)
The Interrupt Status/Control register (INTSTA) contains the flag and enable bits for non-peripheral interrupts. The PEIF bit is a read only, bit wise OR of all the peripheral flag bits in the PIR registers (Figure 6-4 and Figure 6-5). Note: All interrupt flag bits get set by their specified condition, even if the corresponding interrupt enable bit is clear (interrupt disabled), or the GLINTD bit is set (all interrupts disabled). Care should be taken when clearing any of the INTSTA register enable bits when interrupts are enabled (GLINTD is clear). If any of the INTSTA flag bits (T0IF, INTF, T0CKIF, or PEIF) are set in the same instruction cycle as the corresponding interrupt enable bit is cleared, the device will vector to the RESET address (0x00). Prior to disabling any of the INTSTA enable bits, the GLINTD bit should be set (disabled).
REGISTER 6-1: INTSTA REGISTER (ADDRESS: 07h, UNBANKED)
R-0 PEIF bit 7 bit 7 R/W-0 T0CKIF R/W-0 T0IF R/W-0 INTF R/W-0 PEIE R/W-0 T0CKIE R/W-0 T0IE R/W-0 INTE bit 0
PEIF: Peripheral Interrupt Flag bit This bit is the OR of all peripheral interrupt flag bits AND'ed with their corresponding enable bits. The interrupt logic forces program execution to address (20h) when a peripheral interrupt is pending. 1 = A peripheral interrupt is pending 0 = No peripheral interrupt is pending T0CKIF: External Interrupt on T0CKI Pin Flag bit This bit is cleared by hardware, when the interrupt logic forces program execution to address (18h). 1 = The software specified edge occurred on the RA1/T0CKI pin 0 = The software specified edge did not occur on the RA1/T0CKI pin T0IF: TMR0 Overflow Interrupt Flag bit This bit is cleared by hardware, when the interrupt logic forces program execution to address (10h). 1 = TMR0 overflowed 0 = TMR0 did not overflow INTF: External Interrupt on INT Pin Flag bit This bit is cleared by hardware, when the interrupt logic forces program execution to address (08h). 1 = The software specified edge occurred on the RA0/INT pin 0 = The software specified edge did not occur on the RA0/INT pin PEIE: Peripheral Interrupt Enable bit This bit acts as a global enable bit for the peripheral interrupts that have their corresponding enable bits set. 1 = Enable peripheral interrupts 0 = Disable peripheral interrupts T0CKIE: External Interrupt on T0CKI Pin Enable bit 1 = Enable software specified edge interrupt on the RA1/T0CKI pin 0 = Disable interrupt on the RA1/T0CKI pin T0IE: TMR0 Overflow Interrupt Enable bit 1 = Enable TMR0 overflow interrupt 0 = Disable TMR0 overflow interrupt INTE: External Interrupt on RA0/INT Pin Enable bit 1 = Enable software specified edge interrupt on the RA0/INT pin 0 = Disable software specified edge interrupt on the RA0/INT pin Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
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PIC17C7XX
6.2 Peripheral Interrupt Enable Register1 (PIE1) and Register2 (PIE2)
These registers contains the individual enable bits for the peripheral interrupts.
REGISTER 6-2: PIE1 REGISTER (ADDRESS: 17h, BANK 1)
R/W-0 RBIE bit 7 bit 7 RBIE: PORTB Interrupt-on-Change Enable bit 1 = Enable PORTB interrupt-on-change 0 = Disable PORTB interrupt-on-change TMR3IE: TMR3 Interrupt Enable bit 1 = Enable TMR3 interrupt 0 = Disable TMR3 interrupt TMR2IE: TMR2 Interrupt Enable bit 1 = Enable TMR2 interrupt 0 = Disable TMR2 interrupt TMR1IE: TMR1 Interrupt Enable bit 1 = Enable TMR1 interrupt 0 = Disable TMR1 interrupt CA2IE: Capture2 Interrupt Enable bit 1 = Enable Capture2 interrupt 0 = Disable Capture2 interrupt CA1IE: Capture1 Interrupt Enable bit 1 = Enable Capture1 interrupt 0 = Disable Capture1 interrupt TX1IE: USART1 Transmit Interrupt Enable bit 1 = Enable USART1 Transmit buffer empty interrupt 0 = Disable USART1 Transmit buffer empty interrupt RC1IE: USART1 Receive Interrupt Enable bit 1 = Enable USART1 Receive buffer full interrupt 0 = Disable USART1 Receive buffer full interrupt Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown R/W-0 TMR3IE R/W-0 TMR2IE R/W-0 TMR1IE R/W-0 CA2IE R/W-0 CA1IE R/W-0 TX1IE R/W-0 RC1IE bit 0
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
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REGISTER 6-3: PIE2 REGISTER (ADDRESS: 11h, BANK 4)
R/W-0 SSPIE bit 7 bit 7 SSPIE: Synchronous Serial Port Interrupt Enable bit 1 = Enable SSP interrupt 0 = Disable SSP interrupt BCLIE: Bus Collision Interrupt Enable bit 1 = Enable bus collision interrupt 0 = Disable bus collision interrupt ADIE: A/D Module Interrupt Enable bit 1 = Enable A/D module interrupt 0 = Disable A/D module interrupt Unimplemented: Read as `0' CA4IE: Capture4 Interrupt Enable bit 1 = Enable Capture4 interrupt 0 = Disable Capture4 interrupt CA3IE: Capture3 Interrupt Enable bit 1 = Enable Capture3 interrupt 0 = Disable Capture3 interrupt TX2IE: USART2 Transmit Interrupt Enable bit 1 = Enable USART2 Transmit buffer empty interrupt 0 = Disable USART2 Transmit buffer empty interrupt RC2IE: USART2 Receive Interrupt Enable bit 1 = Enable USART2 Receive buffer full interrupt 0 = Disable USART2 Receive buffer full interrupt Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown R/W-0 BCLIE R/W-0 ADIE U-0
--
R/W-0 CA4IE
R/W-0 CA3IE
R/W-0 TX2IE
R/W-0 RC2IE bit 0
bit 6
bit 5
bit 4 bit 3
bit 2
bit 1
bit 0
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PIC17C7XX
6.3 Peripheral Interrupt Request Register1 (PIR1) and Register2 (PIR2)
Note: These bits will be set by the specified condition, even if the corresponding interrupt enable bit is cleared (interrupt disabled), or the GLINTD bit is set (all interrupts disabled). Before enabling an interrupt, the user may wish to clear the interrupt flag to ensure that the program does not immediately branch to the peripheral Interrupt Service Routine.
These registers contains the individual flag bits for the peripheral interrupts.
REGISTER 6-4: PIR1 REGISTER (ADDRESS: 16h, BANK 1)
R/W-x RBIF bit 7 bit 7 RBIF: PORTB Interrupt-on-Change Flag bit 1 = One of the PORTB inputs changed (software must end the mismatch condition) 0 = None of the PORTB inputs have changed TMR3IF: TMR3 Interrupt Flag bit If Capture1 is enabled (CA1/PR3 = 1): 1 = TMR3 overflowed 0 = TMR3 did not overflow If Capture1 is disabled (CA1/PR3 = 0): 1 = TMR3 value has rolled over to 0000h from equalling the period register (PR3H:PR3L) value 0 = TMR3 value has not rolled over to 0000h from equalling the period register (PR3H:PR3L) value bit 5 TMR2IF: TMR2 Interrupt Flag bit 1 = TMR2 value has rolled over to 0000h from equalling the period register (PR2) value 0 = TMR2 value has not rolled over to 0000h from equalling the period register (PR2) value TMR1IF: TMR1 Interrupt Flag bit If TMR1 is in 8-bit mode (T16 = 0): 1 = TMR1 value has rolled over to 0000h from equalling the period register (PR1) value 0 = TMR1 value has not rolled over to 0000h from equalling the period register (PR1) value If Timer1 is in 16-bit mode (T16 = 1): 1 = TMR2:TMR1 value has rolled over to 0000h from equalling the period register (PR2:PR1) value 0 = TMR2:TMR1 value has not rolled over to 0000h from equalling the period register (PR2:PR1) value bit 3 CA2IF: Capture2 Interrupt Flag bit 1 = Capture event occurred on RB1/CAP2 pin 0 = Capture event did not occur on RB1/CAP2 pin CA1IF: Capture1 Interrupt Flag bit 1 = Capture event occurred on RB0/CAP1 pin 0 = Capture event did not occur on RB0/CAP1 pin TX1IF: USART1 Transmit Interrupt Flag bit (state controlled by hardware) 1 = USART1 Transmit buffer is empty 0 = USART1 Transmit buffer is full RC1IF: USART1 Receive Interrupt Flag bit (state controlled by hardware) 1 = USART1 Receive buffer is full 0 = USART1 Receive buffer is empty Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown R/W-0 TMR3IF R/W-0 TMR2IF R/W-0 TMR1IF R/W-0 CA2IF R/W-0 CA1IF R-1 TX1IF R-0 RC1IF bit 0
bit 6
bit 4
bit 2
bit 1
bit 0
2000 Microchip Technology Inc.
DS30289B-page 37
PIC17C7XX
REGISTER 6-5: PIR2 REGISTER (ADDRESS: 10h, BANK 4)
R/W-0 SSPIF bit 7 bit 7 R/W-0 BCLIF R/W-0 ADIF U-0
--
R/W-0 CA4IF
R/W-0 CA3IF
R-1 TX2IF
R-0 RC2IF bit 0
SSPIF: Synchronous Serial Port (SSP) Interrupt Flag bit 1 = The SSP interrupt condition has occurred and must be cleared in software before returning from the Interrupt Service Routine. The conditions that will set this bit are: SPI: A transmission/reception has taken place. I2 C Slave/Master: A transmission/reception has taken place. I2 C Master: The initiated START condition was completed by the SSP module. The initiated STOP condition was completed by the SSP module. The initiated Restart condition was completed by the SSP module. The initiated Acknowledge condition was completed by the SSP module. A START condition occurred while the SSP module was idle (Multi-master system). A STOP condition occurred while the SSP module was idle (Multi-master system). 0 = An SSP interrupt condition has NOT occurred
bit 6
BCLIF: Bus Collision Interrupt Flag bit 1 = A bus collision has occurred in the SSP, when configured for I2C Master mode 0 = No bus collision has occurred ADIF: A/D Module Interrupt Flag bit 1 = An A/D conversion is complete 0 = An A/D conversion is not complete Unimplemented: Read as '0' CA4IF: Capture4 Interrupt Flag bit 1 = Capture event occurred on RE3/CAP4 pin 0 = Capture event did not occur on RE3/CAP4 pin CA3IF: Capture3 Interrupt Flag bit 1 = Capture event occurred on RG4/CAP3 pin 0 = Capture event did not occur on RG4/CAP3 pin TX2IF:USART2 Transmit Interrupt Flag bit (state controlled by hardware) 1 = USART2 Transmit buffer is empty 0 = USART2 Transmit buffer is full RC2IF: USART2 Receive Interrupt Flag bit (state controlled by hardware) 1 = USART2 Receive buffer is full 0 = USART2 Receive buffer is empty Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 5
bit 4 bit 3
bit 2
bit 1
bit 0
DS30289B-page 38
2000 Microchip Technology Inc.
PIC17C7XX
6.4 Interrupt Operation 6.5 RA0/INT Interrupt
Global Interrupt Disable bit, GLINTD (CPUSTA<4>), enables all unmasked interrupts (if clear), or disables all interrupts (if set). Individual interrupts can be disabled through their corresponding enable bits in the INTSTA register. Peripheral interrupts need either the global peripheral enable PEIE bit disabled, or the specific peripheral enable bit disabled. Disabling the peripherals via the global peripheral enable bit, disables all peripheral interrupts. GLINTD is set on RESET (interrupts disabled). The RETFIE instruction clears the GLINTD bit while forcing the Program Counter (PC) to the value loaded at the Top-of-Stack. When an interrupt is responded to, the GLINTD bit is automatically set to disable any further interrupt, the return address is pushed onto the stack and the PC is loaded with the interrupt vector. There are four interrupt vectors which help reduce interrupt latency. The peripheral interrupt vector has multiple interrupt sources. Once in the peripheral Interrupt Service Routine, the source(s) of the interrupt can be determined by polling the interrupt flag bits. The peripheral interrupt flag bit(s) must be cleared in software before reenabling interrupts to avoid continuous interrupts. The PIC17C7XX devices have four interrupt vectors. These vectors and their hardware priority are shown in Table 6-1. If two enabled interrupts occur "at the same time", the interrupt of the highest priority will be serviced first. This means that the vector address of that interrupt will be loaded into the program counter (PC). The external interrupt on the RA0/INT pin is edge triggered. Either the rising edge if the INTEDG bit (T0STA<7>) is set, or the falling edge if the INTEDG bit is clear. When a valid edge appears on the RA0/INT pin, the INTF bit (INTSTA<4>) is set. This interrupt can be disabled by clearing the INTE control bit (INTSTA<0>). The INT interrupt can wake the processor from SLEEP. See Section 17.4 for details on SLEEP operation.
6.6
T0CKI Interrupt
The external interrupt on the RA1/T0CKI pin is edge triggered. Either the rising edge if the T0SE bit (T0STA<6>) is set, or the falling edge if the T0SE bit is clear. When a valid edge appears on the RA1/T0CKI pin, the T0CKIF bit (INTSTA<6>) is set. This interrupt can be disabled by clearing the T0CKIE control bit (INTSTA<2>). The T0CKI interrupt can wake up the processor from SLEEP. See Section 17.4 for details on SLEEP operation.
6.7
Peripheral Interrupt
The peripheral interrupt flag indicates that at least one of the peripheral interrupts occurred (PEIF is set). The PEIF bit is a read only bit and is a bit wise OR of all the flag bits in the PIR registers AND'd with the corresponding enable bits in the PIE registers. Some of the peripheral interrupts can wake the processor from SLEEP. See Section 17.4 for details on SLEEP operation.
6.8
Context Saving During Interrupts
TABLE 6-1:
Address 0008h 0010h 0018h 0020h
INTERRUPT VECTORS/ PRIORITIES
Vector Priority 1 (Highest) 2 3 4 (Lowest)
During an interrupt, only the returned PC value is saved on the stack. Typically, users may wish to save key registers during an interrupt; e.g. WREG, ALUSTA and the BSR registers. This requires implementation in software. Example 6-2 shows the saving and restoring of information for an Interrupt Service Routine. This is for a simple interrupt scheme, where only one interrupt may occur at a time (no interrupt nesting). The SFRs are stored in the non-banked GPR area. Example 6-2 shows the saving and restoring of information for a more complex Interrupt Service Routine. This is useful where nesting of interrupts is required. A maximum of 6 levels can be done by this example. The BSR is stored in the non-banked GPR area, while the other registers would be stored in a particular bank. Therefore, 6 saves may be done with this routine (since there are 6 non-banked GPR registers). These routines require a dedicated indirect addressing register, FSR0, to be selected for this. The PUSH and POP code segments could either be in each Interrupt Service Routine, or could be subroutines that were called. Depending on the application, other registers may also need to be saved.
External Interrupt on RA0/ INT pin (INTF) TMR0 Overflow Interrupt (T0IF) External Interrupt on T0CKI (T0CKIF) Peripherals (PEIF)
Note 1: Individual interrupt flag bits are set, regardless of the status of their corresponding mask bit or the GLINTD bit. 2: Before disabling any of the INTSTA enable bits, the GLINTD bit should be set (disabled).
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DS30289B-page 39
FIGURE 6-2:
DS30289B-page 40 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
PIC17C7XX
Q1
OSC1
OSC2
RA0/INT or RA1/T0CKI
INTF or T0CKIF
INT PIN/T0CKI PIN INTERRUPT TIMING
GLINTD PC PC + 1 Addr (Vector) YY YY + 1 PC + 1
PC
System Bus Instruction Fetched
PC Addr Inst (PC+1) Inst (PC) Inst (PC+1) Addr
Addr Inst (Vector)
Addr
RETFIE
Addr
Inst (YY + 1)
Instruction Executed Inst (PC) Dummy
2000 Microchip Technology Inc.
Dummy
RETFIE
Dummy
PIC17C7XX
EXAMPLE 6-1: SAVING STATUS AND WREG IN RAM (SIMPLE)
; The addresses that are used to store the CPUSTA and WREG values must be in the data memory ; address range of 1Ah - 1Fh. Up to 6 locations can be saved and restored using the MOVFP ; instruction. This instruction neither affects the status bits, nor corrupts the WREG register. ; UNBANK1 EQU 0x01A ; Address for 1st location to save UNBANK2 EQU 0x01B ; Address for 2nd location to save UNBANK3 EQU 0x01C ; Address for 3rd location to save UNBANK4 EQU 0x01D ; Address for 4th location to save UNBANK5 EQU 0x01E ; Address for 5th location to save ; (Label Not used in program) UNBANK6 EQU 0x01F ; Address for 6th location to save ; (Label Not used in program) ; : ; At Interrupt Vector Address PUSH MOVFP ALUSTA, UNBANK1 ; Push ALUSTA value MOVFP BSR, UNBANK2 ; Push BSR value MOVFP WREG, UNBANK3 ; Push WREG value MOVFP PCLATH, UNBANK4 ; Push PCLATH value ; : ; Interrupt Service Routine (ISR) code ; POP MOVFP UNBANK4, PCLATH ; Restore PCLATH value MOVFP UNBANK3, WREG ; Restore WREG value MOVFP UNBANK2, BSR ; Restore BSR value MOVFP UNBANK1, ALUSTA ; Restore ALUSTA value ; RETFIE ; Return from interrupt (enable interrupts)
2000 Microchip Technology Inc.
DS30289B-page 41
PIC17C7XX
EXAMPLE 6-2: SAVING STATUS AND WREG IN RAM (NESTED)
; The addresses that are used to store the CPUSTA and WREG values must be in the data memory ; address range of 1Ah - 1Fh. Up to 6 locations can be saved and restored using the MOVFP ; instruction. This instruction neither affects the status bits, nor corrupts the WREG register. ; This routine uses the FRS0, so it controls the FS1 and FS0 bits in the ALUSTA register. ; Nobank_FSR EQU 0x40 Bank_FSR EQU 0x41 ALU_Temp EQU 0x42 WREG_TEMP EQU 0x43 BSR_S1 EQU 0x01A ; 1st location to save BSR BSR_S2 EQU 0x01B ; 2nd location to save BSR (Label Not used in program) BSR_S3 EQU 0x01C ; 3rd location to save BSR (Label Not used in program) BSR_S4 EQU 0x01D ; 4th location to save BSR (Label Not used in program) BSR_S5 EQU 0x01E ; 5th location to save BSR (Label Not used in program) BSR_S6 EQU 0x01F ; 6th location to save BSR (Label Not used in program) ; INITIALIZATION ; CALL CLEAR_RAM ; Must Clear all Data RAM ; INIT_POINTERS ; Must Initialize the pointers for POP and PUSH CLRF BSR, F ; Set All banks to 0 CLRF ALUSTA, F ; FSR0 post increment BSF ALUSTA, FS1 CLRF WREG, F ; Clear WREG MOVLW BSR_S1 ; Load FSR0 with 1st address to save BSR MOVWF FSR0 MOVWF Nobank_FSR MOVLW 0x20 MOVWF Bank_FSR : : ; Your code : : ; At Interrupt Vector Address PUSH BSF ALUSTA, FS0 ; FSR0 has auto-increment, does not affect status bits BCF ALUSTA, FS1 ; does not affect status bits MOVFP BSR, INDF0 ; No Status bits are affected CLRF BSR, F ; Peripheral and Data RAM Bank 0 No Status bits are affected MOVPF ALUSTA, ALU_Temp ; MOVPF FSR0, Nobank_FSR ; Save the FSR for BSR values MOVPF WREG, WREG_TEMP ; MOVFP Bank_FSR, FSR0 ; Restore FSR value for other values MOVFP ALU_Temp, INDF0 ; Push ALUSTA value MOVFP WREG_TEMP, INDF0 ; Push WREG value MOVFP PCLATH, INDF0 ; Push PCLATH value MOVPF FSR0, Bank_FSR ; Restore FSR value for other values MOVFP Nobank_FSR, FSR0 ; ; : ; Interrupt Service Routine (ISR) code ; POP CLRF ALUSTA, F ; FSR0 has auto-decrement, does not affect status bits MOVFP Bank_FSR, FSR0 ; Restore FSR value for other values DECF FSR0, F ; MOVFP INDF0, PCLATH ; Pop PCLATH value MOVFP INDF0, WREG ; Pop WREG value BSF ALUSTA, FS1 ; FSR0 does not change MOVPF INDF0, ALU_Temp ; Pop ALUSTA value MOVPF FSR0, Bank_FSR ; Restore FSR value for other values DECF Nobank_FSR, F ; MOVFP Nobank_FSR, FSR0 ; Save the FSR for BSR values MOVFP ALU_Temp, ALUSTA ; MOVFP INDF0, BSR ; No Status bits are affected ; RETFIE ; Return from interrupt (enable interrupts)
DS30289B-page 42
2000 Microchip Technology Inc.
PIC17C7XX
7.0 MEMORY ORGANIZATION
FIGURE 7-1:
There are two memory blocks in the PIC17C7XX; program memory and data memory. Each block has its own bus, so that access to each block can occur during the same oscillator cycle. The data memory can further be broken down into General Purpose RAM and the Special Function Registers (SFRs). The operation of the SFRs that control the "core" are described here. The SFRs used to control the peripheral modules are described in the section discussing each individual peripheral module.
PROGRAM MEMORY MAP AND STACK
PC<15:0> 16 CALL, RETURN RETFIE, RETLW Stack Level 1
* * *
Stack Level 16 RESET Vector INT Pin Interrupt Vector Timer0 Interrupt Vector T0CKI Pin Interrupt Vector Peripheral Interrupt Vector
0000h 0008h 0010h 0018h 0020h 0021h
7.1
Program Memory Organization
PIC17C7XX devices have a 16-bit program counter capable of addressing a 64K x 16 program memory space. The RESET vector is at 0000h and the interrupt vectors are at 0008h, 0010h, 0018h, and 0020h (Figure 7-1).
7.1.1
PROGRAM MEMORY OPERATION
The PIC17C7XX can operate in one of four possible program memory configurations. The configuration is selected by configuration bits. The possible modes are: * * * * Microprocessor Microcontroller Extended Microcontroller Protected Microcontroller
User Memory Space(1)
1FFFh (PIC17C752 PIC17C762)
3FFFh (PIC17C756A PIC17C766)
The Extended Microcontroller mode accesses both the internal program memory, as well as external program memory. Execution automatically switches between internal and external memory. The 16-bits of address allow a program memory range of 64K-words. The Microprocessor mode only accesses the external program memory. The on-chip program memory is ignored. The 16-bits of address allow a program memory range of 64K-words. Microprocessor mode is the default mode of an unprogrammed device. The different modes allow different access to the configuration bits, test memory and boot ROM. Table 7-1 lists which modes can access which areas in memory. Test Memory and Boot Memory are not required for normal operation of the device. Care should be taken to ensure that no unintended branches occur to these areas.
Configuration Memory Space
The Microcontroller and Protected Microcontroller modes only allow internal execution. Any access beyond the program memory reads unknown data. The Protected Microcontroller mode also enables the code protection feature.
FOSC0 FOSC1 WDTPS0 WDTPS1 PM0 Reserved PM1 Reserved Reserved BODEN PM2 Test EPROM Boot ROM
FDFFh FE00h FE01h FE02h FE03h FE04h FE05h FE06h FE07h FE08h FE0Dh FE0Eh FE0Fh FE10h FF5Fh FF60h FFFFh
Note 1: User memory space may be internal, external, or both. The memory configuration depends on the processor mode.
2000 Microchip Technology Inc.
DS30289B-page 43
PIC17C7XX
TABLE 7-1:
Operating Mode Microprocessor Microcontroller Extended Microcontroller Protected Microcontroller
MODE MEMORY ACCESS
Internal Program Memory No Access Access Access Access Configuration Bits, Test Memory, Boot ROM No Access Access No Access Access
The PIC17C7XX can operate in modes where the program memory is off-chip. They are the Microprocessor and Extended Microcontroller modes. The Microprocessor mode is the default for an unprogrammed device. Regardless of the processor mode, data memory is always on-chip.
FIGURE 7-2:
MEMORY MAP IN DIFFERENT MODES
Microprocessor Mode 0000h Extended Microcontroller Mode 0000h On-chip Program Memory Microcontroller Modes 0000h On-chip Program Memory PROGRAM SPACE DATA SPACE PROGRAM SPACE DATA SPACE
01FFFh External Program Memory 2000h
01FFFh 2000h
PIC17C752/762
FFFFh FFFFh OFF-CHIP ON-CHIP 00h 120h FFh 1FFh
External Program Memory FE00h Config. Bits Test Memory FFFFh Boot ROM OFF-CHIP ON-CHIP 00h 120h FFh 1FFh FFh OFF-CHIP ON-CHIP 00h 120h 1FFh
ON-CHIP 0000h 0000h
ON-CHIP 0000h On-chip Program Memory 3FFFh
ON-CHIP On-chip Program Memory
3FFFh 4000h
External Program Memory
4000h External Program Memory
PIC17C756A/766
FFFFh FFFFh OFF-CHIP 00h 120h 220h 320h FFh 1FFh 2FFh 3FFh ON-CHIP ON-CHIP
FE00h Config. Bits Test Memory FFFFh Boot ROM OFF-CHIP 00h 120h 220h 320h FFh 1FFh 2FFh 3FFh ON-CHIP FFh ON-CHIP OFF-CHIP 00h 120h 220h 320h 1FFh 2FFh 3FFh ON-CHIP ON-CHIP
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2000 Microchip Technology Inc.
PIC17C7XX
7.1.2 EXTERNAL MEMORY INTERFACE
When either Microprocessor or Extended Microcontroller mode is selected, PORTC, PORTD and PORTE are configured as the system bus. PORTC and PORTD are the multiplexed address/data bus and PORTE<2:0> is for the control signals. External components are needed to demultiplex the address and data. This can be done as shown in Figure 7-4. The waveforms of address and data are shown in Figure 7-3. For complete timings, please refer to the electrical specification section. In Extended Microcontroller mode, when the device is executing out of internal memory, the control signals will continue to be active. That is, they indicate the action that is occurring in the internal memory. The external memory access is ignored. The following selection is for use with Microchip EPROMs. For interfacing to other manufacturers memory, please refer to the electrical specifications of the desired PIC17C7XX device, as well as the desired memory device to ensure compatibility.
TABLE 7-2: FIGURE 7-3: EXTERNAL PROGRAM MEMORY ACCESS WAVEFORMS
Q3 Q4 Q1 Q2 Q3 Q4 Q1
EPROM MEMORY ACCESS TIME ORDERING SUFFIX
Instruction Cycle Time (TCY) 500 ns 250 ns 200 ns 160 ns
Q1 AD <15:0> ALE OE WR '1'
Q2
PIC17C7XX Oscillator Frequency 8 MHz 16 MHz 20 MHz 25 MHz
EPROM Suffix -25 -15 -10 -70
Address out Data in
Address out
Data out
Read Cycle
Write Cycle
Note:
The system bus requires that there is no bus conflict (minimal leakage), so the output value (address) will be capacitively held at the desired value. As the speed of the processor increases, external EPROM memory with faster access time must be used. Table 7-2 lists external memory speed requirements for a given PIC17C7XX device frequency.
The access times for this requires the use of fast SRAMs.
The electrical specifications now include timing specifications for the memory interface with PIC17LCXXX devices. These specifications reflect the capability of the device by characterization. Please validate your design with these timings.
FIGURE 7-4:
TYPICAL EXTERNAL PROGRAM MEMORY CONNECTION DIAGRAM
AD15-AD0
A15-A0 AD7-AD0 373(3)
Memory(3) (MSB) Ax-A0 D7-D0 CE OE WR(2)
Memory(3) (LSB) Ax-A0 D7-D0 CE OE WR(2)
PIC17CXXX
AD15-AD8 ALE
373(3) 138(1)
I/O(1) OE WR Note 1: Use of I/O pins is only required for paged memory. 2: This signal is unused for ROM and EPROM devices. 3: 16-bit wide devices are now common and could be used instead of 8-bit wide devices.
2000 Microchip Technology Inc.
DS30289B-page 45
PIC17C7XX
7.2 Data Memory Organization
7.2.1
Data memory is partitioned into two areas. The first is the General Purpose Registers (GPR) area, and the second is the Special Function Registers (SFR) area. The SFRs control and provide status of device operation. Portions of data memory are banked, this occurs in both areas. The GPR area is banked to allow greater than 232 bytes of general purpose RAM. Banking requires the use of control bits for bank selection. These control bits are located in the Bank Select Register (BSR). If an access is made to the unbanked region, the BSR bits are ignored. Figure 7-5 shows the data memory map organization. Instructions MOVPF and MOVFP provide the means to move values from the peripheral area ("P") to any location in the register file ("F"), and vice-versa. The definition of the "P" range is from 0h to 1Fh, while the "F" range is 0h to FFh. The "P" range has six more locations than peripheral registers, which can be used as General Purpose Registers. This can be useful in some applications where variables need to be copied to other locations in the general purpose RAM (such as saving status information during an interrupt). The entire data memory can be accessed either directly, or indirectly (through file select registers FSR0 and FSR1) (see Section 7.4). Indirect addressing uses the appropriate control bits of the BSR for access into the banked areas of data memory. The BSR is explained in greater detail in Section 7.8.
GENERAL PURPOSE REGISTER (GPR)
All devices have some amount of GPR area. The GPRs are 8-bits wide. When the GPR area is greater than 232, it must be banked to allow access to the additional memory space. All the PIC17C7XX devices have banked memory in the GPR area. To facilitate switching between these banks, the MOVLR bank instruction has been added to the instruction set. GPRs are not initialized by a Poweron Reset and are unchanged on all other RESETS.
7.2.2
SPECIAL FUNCTION REGISTERS (SFR)
The SFRs are used by the CPU and peripheral functions to control the operation of the device (Figure 7-5). These registers are static RAM. The SFRs can be classified into two sets, those associated with the "core" function and those related to the peripheral functions. Those registers related to the "core" are described here, while those related to a peripheral feature are described in the section for each peripheral feature. The peripheral registers are in the banked portion of memory, while the core registers are in the unbanked region. To facilitate switching between the peripheral banks, the MOVLB bank instruction has been provided.
DS30289B-page 46
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 7-5:
Addr Unbanked INDF0 FSR0 PCL PCLATH ALUSTA T0STA CPUSTA INTSTA INDF1 FSR1 WREG TMR0L TMR0H TBLPTRL TBLPTRH BSR Bank 0 Bank 1(1) DDRC PORTC DDRD PORTD DDRE PORTE PIR1 PIE1 Bank 2(1) TMR1 TMR2 TMR3L TMR3H PR1 PR2 PR3L/CA1L PR3H/CA1H Bank 3(1) PW1DCL PW2DCL PW1DCH PW2DCH CA2L CA2H TCON1 TCON2 Bank 4(1) PIR2 PIE2
--
PIC17C7XX REGISTER FILE MAP
00h 01h 02h 03h 04h 05h 06h 07h 08h 09h 0Ah 0Bh 0Ch 0Dh 0Eh 0Fh 10h 11h 12h 13h 14h 15h 16h 17h 18h 19h 1Ah 1Fh 20h
Bank 5(1) DDRF PORTF DDRG PORTG ADCON0 ADCON1 ADRESL ADRESH
Bank 6(1) SSPADD SSPCON1 SSPCON2 SSPSTAT SSPBUF
-- -- --
Bank 7(1) PW3DCL PW3DCH CA3L CA3H CA4L CA4H TCON3
--
Bank 8(1,4) DDRH PORTH DDRJ PORTJ
-- -- -- --
PORTA DDRB PORTB RCSTA1 RCREG1 TXSTA1 TXREG1 SPBRG1 Unbanked PRODL PRODH General Purpose RAM Bank 0(2)
RCSTA2 RCREG2 TXSTA2 TXREG2 SPBRG2
Bank 1(2)
Bank 2(2)
Bank 3(2,3)
General Purpose RAM
General Purpose RAM
General Purpose RAM
General Purpose RAM
FFh Note 1: SFR file locations 10h - 17h are banked. The lower nibble of the BSR specifies the bank. All unbanked SFRs ignore the Bank Select Register (BSR) bits. 2: General Purpose Registers (GPR) locations 20h - FFh, 120h - 1FFh, 220h - 2FFh, and 320h - 3FFh are banked. The upper nibble of the BSR specifies this bank. All other GPRs ignore the Bank Select Register (BSR) bits. 3: RAM bank 3 is not implemented on the PIC17C752 and the PIC17C762. Reading any unimplemented register reads `0's. 4: Bank 8 is only implemented on the PIC17C76X devices.
2000 Microchip Technology Inc.
DS30289B-page 47
PIC17C7XX
TABLE 7-3:
Address
SPECIAL FUNCTION REGISTERS
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR MCLR, WDT
Name
Unbanked 00h INDF0 01h FSR0 02h PCL 03h(1) 04h 05h 06h(2) 07h 08h 09h 0Ah 0Bh 0Ch 0Dh 0Eh 0Fh Bank 0 10h 11h 12h 13h 14h 15h 16h 17h Bank 1 10h 11h 12h 13h 14h 15h 16h 17h Legend: Note 1: 2: 3: 4: 5: 6: DDRC(5) PORTC(4,5) DDRD(5) PORTD(4,5) DDRE(5) PORTE(4,5) PORTA(4,6) DDRB PORTB(4) RCSTA1 RCREG1 TXSTA1 TXREG1 SPBRG1 PCLATH ALUSTA T0STA CPUSTA INTSTA INDF1 FSR1 WREG TMR0L TMR0H TBLPTRL TBLPTRH BSR
Uses contents of FSR0 to address Data Memory (not a physical register) Indirect Data Memory Address Pointer 0 Low order 8-bits of PC Holding Register for upper 8-bits of PC FS3 FS2 FS1 FS0 INTEDG T0SE T0CS T0PS3 OV T0PS2 Z T0PS1 DC T0PS0 POR T0IE C -- BOR INTE
---- ---- ---- ---xxxx xxxx uuuu uuuu 0000 0000 0000 0000 0000 0000 uuuu uuuu 1111 xxxx 1111 uuuu 0000 000- 0000 000--11 11qq --11 qquu 0000 0000 0000 0000 ---- ---- ---- ---xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000
-- -- STKAV GLINTD TO PD PEIF T0CKIF T0IF INTF PEIE T0CKIE Uses contents of FSR1 to address Data Memory (not a physical register) Indirect Data Memory Address Pointer 1 Working Register TMR0 Register; Low Byte TMR0 Register; High Byte Low Byte of Program Memory Table Pointer High Byte of Program Memory Table Pointer Bank Select Register
RBPU
--
RA5/TX1/ CK1
RA4/RX1/ DT1
RA3/SDI/ SDA RB3/ PWM2 -- --
RA2/SS/ SCL RB2/ PWM1 FERR --
RA1/T0CKI
RA0/INT
0-xx 11xx 0-uu 11uu 1111 1111 1111 1111
Data Direction Register for PORTB RB7/ RB6/ RB5/ RB4/ SDO SCK TCLK3 TCLK12 SPEN RX9 SREN CREN Serial Port Receive Register CSRC TX9 TXEN SYNC Serial Port Transmit Register (for USART1) Baud Rate Generator Register (for USART1)
RB1/ CAP2 OERR TRMT
RB0/ CAP1 RX9D TX9D
xxxx xxxx uuuu uuuu 0000 -00x 0000 -00u xxxx xxxx uuuu uuuu 0000 --1x 0000 --1u xxxx xxxx uuuu uuuu 0000 0000 0000 0000
Data Direction Register for PORTC RC7/AD7 RC6/AD6 RC5/AD5 RC4/AD4 Data Direction Register for PORTD RD7/ RD6/ RD5/ RD4/ AD15 AD14 AD13 AD12 Data Direction Register for PORTE
1111 1111 1111 1111
RC3/AD3 RD3/ AD11
RC2/AD2 RD2/ AD10
RC1/AD1
RC0/AD0
xxxx xxxx uuuu uuuu 1111 1111 1111 1111
RD1/AD9
RD0/AD8
xxxx xxxx uuuu uuuu ---- 1111 ---- 1111
RE3/ -- -- -- -- RE2/WR RE1/OE RE0/ALE ---- xxxx ---- uuuu CAP4 x000 0010 u000 0010 PIR1 RBIF TMR3IF TMR2IF TMR1IF CA2IF CA1IF TX1IF RC1IF 0000 0000 0000 0000 PIE1 RBIE TMR3IE TMR2IE TMR1IE CA2IE CA1IE TX1IE RC1IE x = unknown, u = unchanged, - = unimplemented, read as '0', q = value depends on condition. Shaded cells are unimplemented, read as '0'. The upper byte of the program counter is not directly accessible. PCLATH is a holding register for PC<15:8> whose contents are updated from, or transferred to, the upper byte of the program counter. The TO and PD status bits in CPUSTA are not affected by a MCLR Reset. Bank 8 and associated registers are only implemented on the PIC17C76X devices. This is the value that will be in the port output latch. When the device is configured for Microprocessor or Extended Microcontroller mode, the operation of this port does not rely on these registers. On any device RESET, these pins are configured as inputs.
DS30289B-page 48
2000 Microchip Technology Inc.
PIC17C7XX
TABLE 7-3:
Address Bank 2 10h 11h 12h 13h 14h 15h 16h 17h Bank 3 10h 11h 12h 13h 14h 15h 16h 17h Bank 4 10h 11h 12h 13h 14h 15h 16h 17h Bank 5: 10h 11h 12h 13h 14h 15h 16h 17h Legend: Note 1: 2: 3: 4: 5: 6: DDRF PORTF(4) DDRG PORTG(4) ADCON0 ADCON1 ADRESL Data Direction Register for PORTF RF7/ AN11 RF6/ AN10 RF5/ AN9 RF4/ AN8 RF3/ AN7 RF2/ AN6 RF1/ AN5 RF0/ AN4
1111 1111 1111 1111 0000 0000 0000 0000 1111 1111 1111 1111
SPECIAL FUNCTION REGISTERS (CONTINUED)
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR MCLR, WDT
Name
TMR1 TMR2 TMR3L TMR3H PR1 PR2 PR3L/CA1L PR3H/CA1H PW1DCL PW2DCL PW1DCH PW2DCH CA2L CA2H TCON1 TCON2
Timer1's Register Timer2's Register Timer3's Register; Low Byte Timer3's Register; High Byte Timer1's Period Register Timer2's Period Register Timer3's Period Register - Low Byte/Capture1 Register; Low Byte Timer3's Period Register - High Byte/Capture1 Register; High Byte DC1 DC0 DC1 DC0 DC9 DC8 DC9 DC8 Capture2 Low Byte Capture2 High Byte CA2ED1 CA2ED0 CA2OVF -- TM2PW2 DC7 DC7 -- -- DC6 DC6 -- -- DC5 DC5 -- -- DC4 DC4 -- -- DC3 DC3 -- -- DC2 DC2
xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
xx-- ---- uu-- ---xx0- ---- uu0- ---xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
CA1ED1
CA1ED0
T16 CA1/PR3
TMR3CS TMR3ON
TMR2CS TMR2ON
TMR1CS
0000 0000 0000 0000
CA1OVF PWM2ON PWM1ON
TMR1ON 0000 0000 0000 0000
PIR2 PIE2 Unimplemented RCSTA2 RCREG2 TXSTA2 TXREG2 SPBRG2
SSPIF SSPIE -- SPEN
BCLIF BCLIE -- RX9
ADIF ADIE -- SREN
-- -- -- CREN
CA4IF CA4IE -- --
CA3IF CA3IE -- FERR
TX2IF TX2IE -- OERR
RC2IF RC2IE -- RX9D
000- 0010 000- 0010 000- 0000 000- 0000 ---- ---- ---- ---0000 -00x 0000 -00u xxxx xxxx uuuu uuuu
Serial Port Receive Register for USART2 CSRC TX9 TXEN SYNC -- -- TRMT TX9D
0000 --1x 0000 --1u xxxx xxxx uuuu uuuu 0000 0000 0000 0000
Serial Port Transmit Register for USART2 Baud Rate Generator for USART2
Data Direction Register for PORTG RG7/ RG6/ TX2/CK2 RX2/DT2 CHS3 ADCS1 CHS2 ADCS0 RG5/ PWM3 CHS1 ADFM RG4/ CAP3 CHS0 -- RG3/ AN0 -- PCFG3 RG2/ AN1 GO/DONE PCFG2 RG1/ AN2 -- PCFG1 RG0/ AN3 ADON PCFG0
xxxx 0000 uuuu 0000 0000 -0-0 0000 -0-0 000- 0000 000- 0000 xxxx xxxx uuuu uuuu
A/D Result Register Low Byte
xxxx xxxx uuuu uuuu ADRESH A/D Result Register High Byte x = unknown, u = unchanged, - = unimplemented, read as '0', q = value depends on condition. Shaded cells are unimplemented, read as '0'. The upper byte of the program counter is not directly accessible. PCLATH is a holding register for PC<15:8> whose contents are updated from, or transferred to, the upper byte of the program counter. The TO and PD status bits in CPUSTA are not affected by a MCLR Reset. Bank 8 and associated registers are only implemented on the PIC17C76X devices. This is the value that will be in the port output latch. When the device is configured for Microprocessor or Extended Microcontroller mode, the operation of this port does not rely on these registers. On any device RESET, these pins are configured as inputs.
2000 Microchip Technology Inc.
DS30289B-page 49
PIC17C7XX
TABLE 7-3:
Address Bank 6 10h 11h 12h 13h 14h 15h 16h 17h Bank 7 10h 11h 12h 13h 14h 15h 16h 17h Bank 8(3) 10h(3) 11h(3) 12h(3) 13h(3) 14h(3) 15h(3) 16h(3) 17h(3) DDRH PORTH(4) DDRJ PORTJ(4) Unimplemented Unimplemented Unimplemented Unimplemented Data Direction Register for PORTH RH7/ AN15 RH6/ AN14 RH5/ AN13 RH4/ AN12 RH3 RH2 RH1 RH0
1111 1111 1111 1111 xxxx xxxx uuuu uuuu 1111 1111 1111 1111
SPECIAL FUNCTION REGISTERS (CONTINUED)
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR MCLR, WDT
Name
SSPADD SSPCON1 SSPCON2 SSPSTAT SSPBUF Unimplemented Unimplemented Unimplemented
SSP Address Register in I2C Slave mode. SSP Baud Rate Reload Register in I2C Master mode WCOL GCEN SMP SSPOV AKSTAT CKE SSPEN AKDT D/A CKP AKEN P SSPM3 RCEN S SSPM2 PEN R/W SSPM1 RSEN UA SSPM0 SEN BF
0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 xxxx xxxx uuuu uuuu
Synchronous Serial Port Receive Buffer/Transmit Register -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
---- ---- ---- ------- ---- ---- ------- ---- ---- ----
PW3DCL PW3DCH CA3L CA3H CA4L CA4H TCON3 Unimplemented
DC1 DC9
DC0 DC8
TM2PW3 DC7
-- DC6
-- DC5
-- DC4
-- DC3
-- DC2
xx0- ---- uu0- ---xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
Capture3 Low Byte Capture3 High Byte Capture4 Low Byte Capture4 High Byte -- -- CA4OVF -- CA3OVF -- CA4ED1 -- CA4ED0 -- CA3ED1 -- CA3ED0 --
PWM3ON -000 0000 -000 0000 --
---- ---- ---- ----
Data Direction Register for PORTJ RJ7 -- -- -- -- RJ6 -- -- -- -- RJ5 -- -- -- -- RJ4 -- -- -- -- RJ3 -- -- -- -- RJ2 -- -- -- -- RJ1 -- -- -- -- RJ0 -- -- -- --
xxxx xxxx uuuu uuuu ---- ---- ---- ------- ---- ---- ------- ---- ---- ------- ---- ---- ----
Unbanked xxxx xxxx uuuu uuuu 18h PRODL Low Byte of 16-bit Product (8 x 8 Hardware Multiply) xxxx xxxx uuuu uuuu 19h PRODH High Byte of 16-bit Product (8 x 8 Hardware Multiply) Legend: x = unknown, u = unchanged, - = unimplemented, read as '0', q = value depends on condition. Shaded cells are unimplemented, read as '0'. Note 1: The upper byte of the program counter is not directly accessible. PCLATH is a holding register for PC<15:8> whose contents are updated from, or transferred to, the upper byte of the program counter. 2: The TO and PD status bits in CPUSTA are not affected by a MCLR Reset. 3: Bank 8 and associated registers are only implemented on the PIC17C76X devices. 4: This is the value that will be in the port output latch. 5: When the device is configured for Microprocessor or Extended Microcontroller mode, the operation of this port does not rely on these registers. 6: On any device RESET, these pins are configured as inputs.
DS30289B-page 50
2000 Microchip Technology Inc.
PIC17C7XX
7.2.2.1 ALU Status Register (ALUSTA)
The ALUSTA register contains the status bits of the Arithmetic and Logic Unit and the mode control bits for the indirect addressing register. As with all the other registers, the ALUSTA register can be the destination for any instruction. If the ALUSTA register is the destination for an instruction that affects the Z, DC, C, or OV bits, then the write to these three bits is disabled. These bits are set or cleared according to the device logic. Therefore, the result of an instruction with the ALUSTA register as destination may be different than intended. For example, the CLRF ALUSTA, F instruction will clear the upper four bits and set the Z bit. This leaves the ALUSTA register as 0000u1uu (where u = unchanged). It is recommended, therefore, that only BCF, BSF, SWAPF and MOVWF instructions be used to alter the ALUSTA register, because these instructions do not affect any status bits. To see how other instructions affect the status bits, see the "Instruction Set Summary." Note 1: The C and DC bits operate as a borrow and digit borrow bit, respectively, in subtraction. See the SUBLW and SUBWF instructions for examples. 2: The overflow bit will be set if the 2's complement result exceeds +127, or is less than -128. The Arithmetic and Logic Unit (ALU) is capable of carrying out arithmetic or logical operations on two operands, or a single operand. All single operand instructions operate either on the WREG register, or the given file register. For two operand instructions, one of the operands is the WREG register and the other is either a file register, or an 8-bit immediate constant.
REGISTER 7-1: ALUSTA REGISTER (ADDRESS: 04h, UNBANKED)
R/W-1 FS3 bit 7 bit 7-6 FS3:FS2: FSR1 Mode Select bits 00 = Post auto-decrement FSR1 value 01 = Post auto-increment FSR1 value 1x = FSR1 value does not change FS1:FS0: FSR0 Mode Select bits 00 = Post auto-decrement FSR0 value 01 = Post auto-increment FSR0 value 1x = FSR0 value does not change OV: Overflow bit This bit is used for signed arithmetic (2's complement). It indicates an overflow of the 7-bit magnitude, which causes the sign bit (bit7) to change state. 1 = Overflow occurred for signed arithmetic (in this arithmetic operation) 0 = No overflow occurred 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 DC: Digit carry/borrow bit For ADDWF and ADDLW instructions. 1 = A carry-out from the 4th low order bit of the result occurred 0 = No carry-out from the 4th low order bit of the result Note: bit 0 For borrow, the polarity is reversed. C: Carry/borrow bit For ADDWF and ADDLW instructions. Note that a subtraction is executed by adding the two's complement of the second operand. For rotate (RRCF, RLCF) instructions, this bit is loaded with either the high or low order bit of the source register. 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 Note: Legend: R = Readable bit - n = Value at POR Reset
2000 Microchip Technology Inc.
R/W-1 FS2
R/W-1 FS1
R/W-1 FS0
R/W-x OV
R/W-x Z
R/W-x DC
R/W-x C bit 0
bit 5-4
bit 3
bit 2
bit 1
For borrow, the polarity is reversed.
W = Writable bit '1' = Bit is set
U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
DS30289B-page 51
PIC17C7XX
7.2.2.2 CPU Status Register (CPUSTA)
The CPUSTA register contains the status and control bits for the CPU. This register has a bit that is used to globally enable/disable interrupts. If only a specific interrupt is desired to be enabled/disabled, please refer to the Interrupt Status (INTSTA) register and the Peripheral Interrupt Enable (PIE) registers. The CPUSTA register also indicates if the stack is available and contains the Power-down (PD) and Time-out (TO) bits. The TO, PD, and STKAV bits are not writable. These bits are set and cleared according to device logic. Therefore, the result of an instruction with the CPUSTA register as destination may be different than intended. The POR bit allows the differentiation between a Power-on Reset, external MCLR Reset, or a WDT Reset. The BOR bit indicates if a Brown-out Reset occurred. Note 1: The BOR status bit is a don't care and is not necessarily predictable if the Brown-out circuit is disabled (when the BODEN bit in the Configuration word is programmed).
REGISTER 7-2: CPUSTA REGISTER (ADDRESS: 06h, UNBANKED)
U-0 -- bit 7 bit 7-6 bit 5 Unimplemented: Read as '0' STKAV: Stack Available bit This bit indicates that the 4-bit stack pointer value is Fh, or has rolled over from Fh 0h (stack overflow). 1 = Stack is available 0 = Stack is full, or a stack overflow may have occurred (once this bit has been cleared by a stack overflow, only a device RESET will set this bit) GLINTD: Global Interrupt Disable bit This bit disables all interrupts. When enabling interrupts, only the sources with their enable bits set can cause an interrupt. 1 = Disable all interrupts 0 = Enables all unmasked interrupts TO: WDT Time-out Status bit 1 = After power-up, by a CLRWDT instruction, or by a SLEEP instruction 0 = A Watchdog Timer time-out occurred PD: Power-down Status bit 1 = After power-up or by the CLRWDT instruction 0 = By execution of the SLEEP instruction POR: Power-on Reset Status bit 1 = No Power-on Reset occurred 0 = A Power-on Reset occurred (must be set by software) BOR: Brown-out Reset Status bit When BODEN Configuration bit is set (enabled): 1 = No Brown-out Reset occurred 0 = A Brown-out Reset occurred (must be set by software) When BODEN Configuration bit is clear (disabled): Don't care Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown U-0 -- R-1 STKAV R/W-1 GLINTD R-1 TO R-1 PD R/W-0 POR R/W-1 BOR bit 0
bit 4
bit 3
bit 2
bit 1
bit 0
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PIC17C7XX
7.2.2.3 TMR0 Status/Control Register (T0STA)
This register contains various control bits. Bit7 (INTEDG) is used to control the edge upon which a signal on the RA0/INT pin will set the RA0/INT interrupt flag. The other bits configure Timer0, it's prescaler and clock source.
REGISTER 7-3: T0STA REGISTER (ADDRESS: 05h, UNBANKED)
R/W-0 INTEDG bit 7 bit 7 INTEDG: RA0/INT Pin Interrupt Edge Select bit This bit selects the edge upon which the interrupt is detected. 1 = Rising edge of RA0/INT pin generates interrupt 0 = Falling edge of RA0/INT pin generates interrupt T0SE: Timer0 External Clock Input Edge Select bit This bit selects the edge upon which TMR0 will increment. When T0CS = 0 (External Clock): 1 = Rising edge of RA1/T0CKI pin increments TMR0 and/or sets the T0CKIF bit 0 = Falling edge of RA1/T0CKI pin increments TMR0 and/or sets a T0CKIF bit When T0CS = 1 (Internal Clock): Don't care bit 5 T0CS: Timer0 Clock Source Select bit This bit selects the clock source for Timer0. 1 = Internal instruction clock cycle (TCY) 0 = External clock input on the T0CKI pin T0PS3:T0PS0: Timer0 Prescale Selection bits These bits select the prescale value for Timer0. T0PS3:T0PS0 0000 0001 0010 0011 0100 0101 0110 0111 1xxx bit 0 Prescale Value 1:1 1:2 1:4 1:8 1:16 1:32 1:64 1:128 1:256 R/W-0 T0SE R/W-0 T0CS R/W-0 T0PS3 R/W-0 T0PS2 R/W-0 T0PS1 R/W-0 T0PS0 U-0 -- bit 0
bit 6
bit 4-1
Unimplemented: Read as '0' Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
2000 Microchip Technology Inc.
DS30289B-page 53
PIC17C7XX
7.3 Stack Operation 7.4 Indirect Addressing
PIC17C7XX devices have a 16 x 16-bit hardware stack (Figure 7-1). The stack is not part of either the program or data memory space, and the stack pointer is neither readable nor writable. The PC (Program Counter) is "PUSH'd" onto the stack when a CALL or LCALL instruction is executed, or an interrupt is acknowledged. The stack is "POP'd" in the event of a RETURN, RETLW, or a RETFIE instruction execution. PCLATH is not affected by a "PUSH" or a "POP" operation. The stack operates as a circular buffer, with the stack pointer initialized to '0' after all RESETS. There is a stack available bit (STKAV) to allow software to ensure that the stack will not overflow. The STKAV bit is set after a device RESET. When the stack pointer equals Fh, STKAV is cleared. When the stack pointer rolls over from Fh to 0h, the STKAV bit will be held clear until a device RESET. Indirect addressing is a mode of addressing data memory where the data memory address in the instruction is not fixed. That is, the register that is to be read or written can be modified by the program. This can be useful for data tables in the data memory. Figure 7-6 shows the operation of indirect addressing. This depicts the moving of the value to the data memory address specified by the value of the FSR register. Example 7-1 shows the use of indirect addressing to clear RAM in a minimum number of instructions. A similar concept could be used to move a defined number of bytes (block) of data to the USART transmit register (TXREG). The starting address of the block of data to be transmitted could easily be modified by the program.
FIGURE 7-6:
INDIRECT ADDRESSING
RAM
Note 1: There is not a status bit for stack underflow. The STKAV bit can be used to detect the underflow which results in the stack pointer being at the Top-of-Stack. 2: There are no instruction mnemonics called PUSH or POP. These are actions that occur from the execution of the CALL, RETURN, RETLW and RETFIE instructions, or the vectoring to an interrupt vector. 3: After a RESET, if a "POP" operation occurs before a "PUSH" operation, the STKAV bit will be cleared. This will appear as if the stack is full (underflow has occurred). If a "PUSH" operation occurs next (before another "POP"), the STKAV bit will be locked clear. Only a device RESET will cause this bit to set. After the device is "PUSH'd" sixteen times (without a "POP"), the seventeenth push overwrites the value from the first push. The eighteenth push overwrites the second push (and so on).
Instruction Executed Opcode Address 8 File = INDFx
Instruction Fetched Opcode
8 File
8 FSR
7.4.1
INDIRECT ADDRESSING REGISTERS
The PIC17C7XX has four registers for indirect addressing. These registers are: * INDF0 and FSR0 * INDF1 and FSR1 Registers INDF0 and INDF1 are not physically implemented. Reading or writing to these registers activates indirect addressing, with the value in the corresponding FSR register being the address of the data. The FSR is an 8-bit register and allows addressing anywhere in the 256-byte data memory address range. For banked memory, the bank of memory accessed is specified by the value in the BSR. If file INDF0 (or INDF1) itself is read indirectly via an FSR, all '0's are read (Zero bit is set). Similarly, if INDF0 (or INDF1) is written to indirectly, the operation will be equivalent to a NOP, and the status bits are not affected.
DS30289B-page 54
2000 Microchip Technology Inc.
PIC17C7XX
7.4.2 INDIRECT ADDRESSING OPERATION
7.5
Table Pointer (TBLPTRL and TBLPTRH)
The indirect addressing capability has been enhanced over that of the PIC16CXX family. There are two control bits associated with each FSR register. These two bits configure the FSR register to: * Auto-decrement the value (address) in the FSR after an indirect access * Auto-increment the value (address) in the FSR after an indirect access * No change to the value (address) in the FSR after an indirect access These control bits are located in the ALUSTA register. The FSR1 register is controlled by the FS3:FS2 bits and FSR0 is controlled by the FS1:FS0 bits. When using the auto-increment or auto-decrement features, the effect on the FSR is not reflected in the ALUSTA register. For example, if the indirect address causes the FSR to equal '0', the Z bit will not be set. If the FSR register contains a value of 0h, an indirect read will read 0h (Zero bit is set) while an indirect write will be equivalent to a NOP (status bits are not affected). Indirect addressing allows single cycle data transfers within the entire data space. This is possible with the use of the MOVPF and MOVFP instructions, where either 'p' or 'f' is specified as INDF0 (or INDF1). If the source or destination of the indirect address is in banked memory, the location accessed will be determined by the value in the BSR. A simple program to clear RAM from 20h - FFh is shown in Example 7-1.
File registers TBLPTRL and TBLPTRH form a 16-bit pointer to address the 64K program memory space. The table pointer is used by instructions TABLWT and TABLRD. The TABLRD and the TABLWT instructions allow transfer of data between program and data space. The table pointer serves as the 16-bit address of the data word within the program memory. For a more complete description of these registers and the operation of Table Reads and Table Writes, see Section 8.0.
7.6
Table Latch (TBLATH, TBLATL)
The table latch (TBLAT) is a 16-bit register, with TBLATH and TBLATL referring to the high and low bytes of the register. It is not mapped into data or program memory. The table latch is used as a temporary holding latch during data transfer between program and data memory (see TABLRD, TABLWT, TLRD and TLWT instruction descriptions). For a more complete description of these registers and the operation of Table Reads and Table Writes, see Section 8.0.
EXAMPLE 7-1:
MOVLW MOVWF BCF BSF BCF MOVLW CLRF CPFSEQ GOTO : :
INDIRECT ADDRESSING
; ; ; ; ; ; ; ; ; ; ;
LP
0x20 FSR0 ALUSTA, FS1 ALUSTA, FS0 ALUSTA, C END_RAM + 1 INDF0, F FSR0 LP
FSR0 = 20h Increment FSR after access C=0 Addr(FSR) = 0 FSR0 = END_RAM+1? NO, clear next YES, All RAM is cleared
2000 Microchip Technology Inc.
DS30289B-page 55
PIC17C7XX
7.7 Program Counter Module
The Program Counter (PC) is a 16-bit register. PCL, the low byte of the PC, is mapped in the data memory. PCL is readable and writable just as is any other register. PCH is the high byte of the PC and is not directly addressable. Since PCH is not mapped in data or program memory, an 8-bit register PCLATH (PC high latch) is used as a holding latch for the high byte of the PC. PCLATH is mapped into data memory. The user can read or write PCH through PCLATH. The 16-bit wide PC is incremented after each instruction fetch during Q1 unless: * Modified by a GOTO, CALL, LCALL, RETURN, RETLW, or RETFIE instruction * Modified by an interrupt response * Due to destination write to PCL by an instruction "Skips" are equivalent to a forced NOP cycle at the skipped address. Figure 7-7 and Figure 7-8 show the operation of the program counter for various situations. Using Figure 7-7, the operations of the PC and PCLATH for different instructions are as follows: a) LCALL instructions: An 8-bit destination address is provided in the instruction (opcode). PCLATH is unchanged. PCLATH PCH Opcode<7:0> PCL Read instructions on PCL: Any instruction that reads PCL. PCL data bus ALU or destination PCH PCLATH Write instructions on PCL: Any instruction that writes to PCL. 8-bit data data bus PCL PCLATH PCH Read-Modify-Write instructions on PCL: Any instruction that does a read-write-modify operation on PCL, such as ADDWF PCL. Read: PCL data bus ALU Write: 8-bit result data bus PCL PCLATH PCH RETURN instruction: Stack PC<15:0>
b)
c)
d)
FIGURE 7-7:
PROGRAM COUNTER OPERATION
Internal Data Bus <8> 8 PCLATH 8 PCH PCL 8
e)
Using Figure 7-8, the operation of the PC and PCLATH for GOTO and CALL instructions is as follows: CALL, GOTO instructions: A 13-bit destination address is provided in the instruction (opcode). Opcode<12:0> PC<12:0> PC<15:13> PCLATH<7:5> Opcode<12:8> PCLATH<4:0> The read-modify-write only affects the PCL with the result. PCH is loaded with the value in the PCLATH. For example, ADDWF PCL will result in a jump within the current page. If PC = 03F0h, WREG = 30h and PCLATH = 03h before instruction, PC = 0320h after the instruction. To accomplish a true 16-bit computed jump, the user needs to compute the 16-bit destination address, write the high byte to PCLATH and then write the low value to PCL. The following PC related operations do not change PCLATH: a) b) c) LCALL, RETLW, and RETFIE instructions. Interrupt vector is forced onto the PC. Read-modify-write instructions on PCL (e.g. BSF PCL).
FIGURE 7-8:
PROGRAM COUNTER USING THE CALL AND GOTO INSTRUCTIONS
87 From Instruction 0
15
13 12
PC<15:13> 3 7
5 8
54 0 PCLATH 8
15 PCH
87 PCL
0
DS30289B-page 56
2000 Microchip Technology Inc.
PIC17C7XX
7.8 Bank Select Register (BSR)
The BSR is used to switch between banks in the data memory area (Figure 7-9). In the PIC17C7XX devices, the entire byte is implemented. The lower nibble is used to select the peripheral register bank. The upper nibble is used to select the general purpose memory bank. All the Special Function Registers (SFRs) are mapped into the data memory space. In order to accommodate the large number of registers, a banking scheme has been used. A segment of the SFRs, from address 10h to address 17h, is banked. The lower nibble of the bank select register (BSR) selects the currently active "peripheral bank." Effort has been made to group the peripheral registers of related functionality in one bank. However, it will still be necessary to switch from bank to bank in order to address all peripherals related to a single task. To assist this, a MOVLB bank instruction has been included in the instruction set. The need for a large general purpose memory space dictated a general purpose RAM banking scheme. The upper nibble of the BSR selects the currently active general purpose RAM bank. To assist this, a MOVLR bank instruction has been provided in the instruction set. If the currently selected bank is not implemented (such as Bank 13), any read will read all '0's. Any write is completed to the bit bucket and the ALU status bits will be set/cleared as appropriate. Note: Registers in Bank 15 in the Special Function Register area, are reserved for Microchip use. Reading of registers in this bank may cause random values to be read.
FIGURE 7-9:
BSR 7 43
(2) (1)
BSR OPERATION
0
Address Range 10h 17h
0
1
2
3
4
5
6
7
8 ***
15 SFR (Peripheral) Banks
Bank 0 Bank 1 Bank 2 Bank 3 Bank 4 Bank 5 Bank 6 Bank 7 Bank 8
Bank 15
0 20h FFh
1
2
3
4 ***
15 GPR (RAM) Banks Bank 15
Bank 0 Bank 1 Bank 2 Bank 3 Bank 4
Note 1: For the SFRs only Banks 0 through 8 are implemented. Selection of an unimplemented bank is not recommended. Bank 15 is reserved for Microchip use, reading of registers in this bank may cause random values to be read. 2: For the GPRs, Bank 3 is unimplemented on the PIC17C752 and the PIC17C762. Selection of an unimplemented bank is not recommended. 3: SFR Bank 8 is only implemented on the PIC17C76X.
2000 Microchip Technology Inc.
DS30289B-page 57
PIC17C7XX
NOTES:
DS30289B-page 58
2000 Microchip Technology Inc.
PIC17C7XX
8.0 TABLE READS AND TABLE WRITES
FIGURE 8-2:
TABLWT INSTRUCTION OPERATION
The PIC17C7XX has four instructions that allow the processor to move data from the data memory space to the program memory space, and vice versa. Since the program memory space is 16-bits wide and the data memory space is 8-bits wide, two operations are required to move 16-bit values to/from the data memory. The TLWT t,f and TABLWT t,i,f instructions are used to write data from the data memory space to the program memory space. The TLRD t,f and TABLRD t,i,f instructions are used to write data from the program memory space to the data memory space. The program memory can be internal or external. For the program memory access to be external, the device needs to be operating in Microprocessor or Extended Microcontroller mode. Figure 8-1 through Figure 8-4 show the operation of these four instructions. The steps show the sequence of operation.
TABLE POINTER TBLPTRH TABLE LATCH (16-bit) TABLATH TABLATL TBLPTRL
3 TABLWT 1,i,f
3 TABLWT 0,i,f
Data Memory
Program Memory
f
1 Prog-Mem (TBLPTR) 2
FIGURE 8-1:
TLWT INSTRUCTION OPERATION
TBLPTRH
TABLE POINTER TBLPTRL
TABLE LATCH (16-bit) TABLATH TABLATL Step 1: 8-bit value from register 'f', loaded into the high or low byte in TABLAT (16-bit). 2: 16-bit TABLAT value written to address Program Memory (TBLPTR). 3: If "i" = 1, then TBLPTR = TBLPTR + 1, If "i" = 0, then TBLPTR is unchanged.
TLWT 1,f Data Memory
TLWT 0,f Program Memory
f 1
Step 1: 8-bit value from register 'f', loaded into the high or low byte in TABLAT (16-bit).
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FIGURE 8-3:
TLRD INSTRUCTION OPERATION
TBLPTRH TABLE LATCH (16-bit) TABLATH TLRD 1,f Data Memory TABLATL TLRD 0,f 3 TABLRD 1,i,f Program Memory Data Memory Program Memory 3 TABLRD 0,i,f TBLPTRL
FIGURE 8-4:
TABLRD INSTRUCTION OPERATION
TBLPTRH TBLPTRL
TABLE POINTER
TABLE POINTER
TABLE LATCH (16-bit) TABLATH TABLATL
f
1 f 1 Prog-Mem (TBLPTR) 2
Step 1: 8-bit value from TABLAT (16-bit) high or low byte, loaded into register 'f'.
Step 1: 8-bit value from TABLAT (16-bit) high or low byte, loaded into register 'f'. 2: 16-bit value at Program Memory (TBLPTR), loaded into TABLAT register. 3: If "i" = 1, then TBLPTR = TBLPTR + 1, If "i" = 0, then TBLPTR is unchanged.
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PIC17C7XX
8.1 Table Writes to Internal Memory
8.1.1 TERMINATING LONG WRITES
A table write operation to internal memory causes a long write operation. The long write is necessary for programming the internal EPROM. Instruction execution is halted while in a long write cycle. The long write will be terminated by any enabled interrupt. To ensure that the EPROM location has been well programmed, a minimum programming time is required (see specification #D114). Having only one interrupt enabled to terminate the long write ensures that no unintentional interrupts will prematurely terminate the long write. The sequence of events for programming an internal program memory location should be: 1. 2. 3. 4. 5. Disable all interrupt sources, except the source to terminate EPROM program write. Raise MCLR/VPP pin to the programming voltage. Clear the WDT. Do the table write. The interrupt will terminate the long write. Verify the memory location (table read). Note 1: Programming requirements must be met. See timing specification in electrical specifications for the desired device. Violating these specifications (including temperature) may result in EPROM locations that are not fully programmed and may lose their state over time. 2: If the VPP requirement is not met, the table write is a 2-cycle write and the program memory is unchanged. An interrupt source or RESET are the only events that terminate a long write operation. Terminating the long write from an interrupt source requires that the interrupt enable and flag bits are set. The GLINTD bit only enables the vectoring to the interrupt address. If the T0CKI, RA0/INT, or TMR0 interrupt source is used to terminate the long write, the interrupt flag of the highest priority enabled interrupt, will terminate the long write and automatically be cleared. Note 1: If an interrupt is pending, the TABLWT is aborted (a NOP is executed). The highest priority pending interrupt, from the T0CKI, RA0/INT, or TMR0 sources that is enabled, has its flag cleared. 2: If the interrupt is not being used for the program write timing, the interrupt should be disabled. This will ensure that the interrupt is not lost, nor will it terminate the long write prematurely. If a peripheral interrupt source is used to terminate the long write, the interrupt enable and flag bits must be set. The interrupt flag will not be automatically cleared upon the vectoring to the interrupt vector address. The GLINTD bit determines whether the program will branch to the interrupt vector when the long write is terminated. If GLINTD is clear, the program will vector, if GLINTD is set, the program will not vector to the interrupt address.
TABLE 8-1:
Interrupt Source RA0/INT, TMR0, T0CKI
INTERRUPT - TABLE WRITE INTERACTION
GLINTD 0 0 1 1 Enable Bit 1 1 0 1 Flag Bit 1 0 x 1 Action Terminate long table write (to internal program memory), branch to interrupt vector (branch clears flag bit). None. None. Terminate long table write, do not branch to interrupt vector (flag is automatically cleared). Terminate long table write, branch to interrupt vector. None. None. Terminate long table write, do not branch to interrupt vector (flag remains set).
Peripheral
0 0 1 1
1 1 0 1
1 0 x 1
2000 Microchip Technology Inc.
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8.2 Table Writes to External Memory
EXAMPLE 8-1:
CLRWDT MOVLW MOVWF MOVLW MOVWF MOVLW TLWT MOVLW TABLWT
TABLE WRITE
; ; ; ; ; ; ; ; ; ; ; ; Clear WDT Load the Table address
Table writes to external memory are always two-cycle instructions. The second cycle writes the data to the external memory location. The sequence of events for an external memory write are the same for an internal write.
8.2.1
TABLE WRITE CODE
The "i" operand of the TABLWT instruction can specify that the value in the 16-bit TBLPTR register is automatically incremented (for the next write). In Example 8-1, the TBLPTR register is not automatically incremented.
HIGH (TBL_ADDR) TBLPTRH LOW (TBL_ADDR) TBLPTRL HIGH (DATA) 1, WREG LOW (DATA) 0,0,WREG
Load HI byte in TABLATH Load LO byte in TABLATL and write to program memory (Ext. SRAM)
FIGURE 8-5:
TABLWT WRITE TIMING (EXTERNAL MEMORY)
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
AD15:AD0
PC
PC+1
TBL
Data out
PC+2
Instruction Fetched Instruction Executed
TABLWT INST (PC-1)
INST (PC+1) TABLWT cycle1 TABLWT cycle2 Data write cycle
INST (PC+2) INST (PC+1)
ALE OE '1' WR
Note: If external write and GLINTD = '1' and Enable bit = '1', then when '1' Flag bit, do table write. The highest pending interrupt is cleared.
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PIC17C7XX
FIGURE 8-6: CONSECUTIVE TABLWT WRITE TIMING (EXTERNAL MEMORY)
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
AD15:AD0 Instruction Fetched Instruction Executed
PC
PC+1
TBL1
Data out 1
PC+2
TBL2
Data out 2
PC+3
TABLWT1 INST (PC-1)
TABLWT2
INST (PC+2)
INST (PC+3) INST (PC+2)
TABLWT1 cycle1 TABLWT1 cycle2 TABLWT2 cycle1 TABLWT2 cycle2 Data write cycle Data write cycle
ALE OE WR
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8.3 Table Reads
EXAMPLE 8-2:
MOVLW MOVWF MOVLW MOVWF TABLRD
TABLE READ
The table read allows the program memory to be read. This allows constants to be stored in the program memory space and retrieved into data memory when needed. Example 8-2 reads the 16-bit value at program memory address TBLPTR. After the dummy byte has been read from the TABLATH, the TABLATH is loaded with the 16-bit data from program memory address TBLPTR and then increments the TBLPTR value. The first read loads the data into the latch and can be considered a dummy read (unknown data loaded into 'f'). INDF0 should be configured for either auto-increment or auto-decrement.
TLRD TABLRD
HIGH (TBL_ADDR) ; Load the Table TBLPTRH ; address LOW (TBL_ADDR) ; TBLPTRL ; 0, 1, DUMMY ; Dummy read, ; Updates TABLATH ; Increments TBLPTR 1, INDF0 ; Read HI byte ; of TABLATH 0, 1, INDF0 ; Read LO byte ; of TABLATL and ; Update TABLATH ; Increment TBLPTR
FIGURE 8-7:
TABLRD TIMING
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
AD15:AD0
PC
PC+1
TBL
Data in
PC+2
Instruction Fetched Instruction Executed
TABLRD INST (PC-1)
INST (PC+1) TABLRD cycle2 Data read cycle
INST (PC+2) INST (PC+1)
TABLRD cycle1
ALE OE '1'
WR
FIGURE 8-8:
TABLRD TIMING (CONSECUTIVE TABLRD INSTRUCTIONS)
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
AD15:AD0 Instruction Fetched Instruction Executed
PC
PC+1
TBL1 Data in 1
PC+2
TBL2
Data in 2
PC+3
TABLRD1 INST (PC-1)
TABLRD2
INST (PC+2)
INST (PC+3) INST (PC+2)
TABLRD1 cycle1 TABLRD1 cycle2 TABLRD2 cycle1 TABLRD2 cycle2 Data read cycle Data read cycle
ALE OE '1' WR
DS30289B-page 64
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PIC17C7XX
8.4 Operation with External Memory Interface
When the table reads/writes are accessing external memory (via the external system interface bus), the table latch for the table reads is different from the table latch for the table writes (see Figure 8-9). This means that you cannot do a TABLRD instruction, and use the values that were loaded into the table latches for a TABLWT instruction. Any table write sequence should use both the TLWT and then the TABLWT instructions.
FIGURE 8-9:
ACCESSING EXTERNAL MEMORY WITH TABLRD AND TABLWT INSTRUCTIONS
TABLPTR Program Memory (In External Memory Space)
TABLATH (for Table Reads) TABLRD
TABLATH (for Table Writes)
TABLWT
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NOTES:
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PIC17C7XX
9.0 HARDWARE MULTIPLIER
All PIC17C7XX devices have an 8 x 8 hardware multiplier included in the ALU of the device. By making the multiply a hardware operation, it completes in a single instruction cycle. This is an unsigned multiply that gives a 16-bit result. The result is stored into the 16-bit Product register (PRODH:PRODL). The multiplier does not affect any flags in the ALUSTA register. Making the 8 x 8 multiplier execute in a single cycle gives the following advantages: * Higher computational throughput * Reduces code size requirements for multiply algorithms The performance increase allows the device to be used in applications previously reserved for Digital Signal Processors. Table 9-1 shows a performance comparison between PIC17CXXX devices using the single cycle hardware multiply and performing the same function without the hardware multiply. Example 9-1 shows the sequence to do an 8 x 8 unsigned multiply. Only one instruction is required when one argument of the multiply is already loaded in the WREG register. Example 9-2 shows the sequence to do an 8 x 8 signed multiply. To account for the sign bits of the arguments, each argument's most significant bit (MSb) is tested and the appropriate subtractions are done.
EXAMPLE 9-1:
8 x 8 UNSIGNED MULTIPLY ROUTINE
ARG1, WREG ARG2 ; ; ARG1 * ARG2 -> ; PRODH:PRODL
MOVFP MULWF
EXAMPLE 9-2:
8 x 8 SIGNED MULTIPLY ROUTINE
ARG1, WREG ARG2 ARG2, SB PRODH, F ARG2, WREG ARG1, SB PRODH, F
MOVFP MULWF BTFSC SUBWF MOVFP BTFSC SUBWF
; ARG1 * ARG2 -> ; PRODH:PRODL ; Test Sign Bit ; PRODH = PRODH ; - ARG1 ; Test Sign Bit ; PRODH = PRODH ; - ARG2
TABLE 9-1:
Routine 8 x 8 unsigned 8 x 8 signed 16 x 16 unsigned 16 x 16 signed
PERFORMANCE COMPARISON
Multiply Method Without hardware multiply Hardware multiply Without hardware multiply Hardware multiply Without hardware multiply Hardware multiply Without hardware multiply Hardware multiply Program Memory (Words) 13 1 -- 6 21 24 52 36 Cycles (Max) 69 1 -- 6 242 24 254 36 Time @ 33 MHz 8.364 s 0.121 s -- 0.727 s 29.333 s 2.91 s 30.788 s 4.36 s @ 16 MHz 17.25 s 0.25 s -- 1.50 s 60.50 s 6.0 s 63.50 s 9.0 s @ 8 MHz 34.50 s 0.50 s -- 3.0 s 121.0 s 12.0 s 127.0 s 18.0 s
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PIC17C7XX
Example 9-3 shows the sequence to do a 16 x 16 unsigned multiply. Equation 9-1 shows the algorithm that is used. The 32-bit result is stored in 4 registers, RES3:RES0.
EXAMPLE 9-3:
MOVFP MULWF MOVPF MOVPF ; MOVFP MULWF MOVPF MOVPF ; MOVFP MULWF MOVFP ADDWF MOVFP ADDWFC CLRF ADDWFC ; MOVFP MULWF MOVFP ADDWF MOVFP ADDWFC CLRF ADDWFC
16 x 16 UNSIGNED MULTIPLY ROUTINE
EQUATION 9-1:
16 x 16 UNSIGNED MULTIPLICATION ALGORITHM
ARG1H:ARG1L * ARG2H:ARG2L (ARG1H * ARG2H * 2 )
16
ARG1L, WREG ARG2L ; ARG1L * ARG2L -> ; PRODH:PRODL PRODH, RES1 ; PRODL, RES0 ; ARG1H, WREG ARG2H ; ARG1H * ARG2H -> ; PRODH:PRODL PRODH, RES3 ; PRODL, RES2 ; ARG1L, WREG ARG2H ; ARG1L * ARG2H -> ; PRODH:PRODL PRODL, WREG ; RES1, F ; Add cross PRODH, WREG ; products RES2, F ; WREG, F ; RES3, F ; ARG1H, WREG ; ARG2L ; ARG1H * ARG2L -> ; PRODH:PRODL PRODL, WREG ; RES1, F ; Add cross PRODH, WREG ; products RES2, F ; WREG, F ; RES3, F ;
RES3:RES0 = =
+ + +
(ARG1H * ARG2L * 2 )
8
(ARG1L * ARG2H * 28) (ARG1L * ARG2L)
DS30289B-page 68
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PIC17C7XX
Example 9-4 shows the sequence to do a 16 x 16 signed multiply. Equation 9-2 shows the algorithm used. The 32-bit result is stored in four registers, RES3:RES0. To account for the sign bits of the arguments, each argument pairs most significant bit (MSb) is tested and the appropriate subtractions are done.
EXAMPLE 9-4:
MOVFP MULWF MOVPF MOVPF ; MOVFP MULWF MOVPF MOVPF
16 x 16 SIGNED MULTIPLY ROUTINE
EQUATION 9-2:
16 x 16 SIGNED MULTIPLICATION ALGORITHM
ARG1L, WREG ARG2L ; ARG1L * ARG2L -> ; PRODH:PRODL PRODH, RES1 ; PRODL, RES0 ; ARG1H, WREG ARG2H ; ARG1H * ARG2H -> ; PRODH:PRODL PRODH, RES3 ; PRODL, RES2 ; ARG1L, WREG ARG2H ; ARG1L * ARG2H -> ; PRODH:PRODL PRODL, WREG ; RES1, F ; Add cross PRODH, WREG ; products RES2, F ; WREG, F ; RES3, F ; ARG1H, WREG ; ARG2L ; ARG1H * ARG2L -> ; PRODH:PRODL PRODL, WREG ; RES1, F ; Add cross PRODH, WREG ; products RES2, F ; WREG, F ; RES3, F ; ARG2H, 7 SIGN_ARG1 ARG1L, WREG RES2 ARG1H, WREG RES3 ; ARG2H:ARG2L neg? ; no, check ARG1 ; ; ;
RES3:RES0 = ARG1H:ARG1L * ARG2H:ARG2L = (ARG1H * ARG2H * 216) (ARG1H * ARG2L * 28) (ARG1L * ARG2H * 28) (ARG1L * ARG2L) (-1 * ARG2H<7> * ARG1H:ARG1L * 216) (-1 * ARG1H<7> * ARG2H:ARG2L * 2 )
16
+ + + + +
; MOVFP MULWF MOVFP ADDWF MOVFP ADDWFC CLRF ADDWFC ; MOVFP MULWF MOVFP ADDWF MOVFP ADDWFC CLRF ADDWFC ; BTFSS GOTO MOVFP SUBWF MOVFP SUBWFB ; SIGN_ARG1 BTFSS GOTO MOVFP SUBWF MOVFP SUBWFB ; CONT_CODE :
ARG1H, 7 CONT_CODE ARG2L, WREG RES2 ARG2H, WREG RES3
; ARG1H:ARG1L neg? ; no, done ; ; ;
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NOTES:
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PIC17C7XX
10.0 I/O PORTS
PIC17C75X devices have seven I/O ports, PORTA through PORTG. PIC17C76X devices have nine I/O ports, PORTA through PORTJ. PORTB through PORTJ have a corresponding Data Direction Register (DDR), which is used to configure the port pins as inputs or outputs. Some of these ports pins are multiplexed with alternate functions. PORTC, PORTD, and PORTE are multiplexed with the system bus. These pins are configured as the system bus when the device's configuration bits are selected to Microprocessor or Extended Microcontroller modes. In the two other microcontroller modes, these pins are general purpose I/O. PORTA, PORTB, PORTE<3>, PORTF, PORTG and the upper four bits of PORTH are multiplexed with the peripheral features of the device. These peripheral features are: * * * * * * * Timer Modules Capture Modules PWM Modules USART/SCI Modules SSP Module A/D Module External Interrupt pin When some of these peripheral modules are turned on, the port pin will automatically configure to the alternate function. The modules that do this are: * PWM Module * SSP Module * USART/SCI Module When a pin is automatically configured as an output by a peripheral module, the pins data direction (DDR) bit is unknown. After disabling the peripheral module, the user should re-initialize the DDR bit to the desired configuration. The other peripheral modules (which require an input) must have their data direction bits configured appropriately. Note: A pin that is a peripheral input, can be configured as an output (DDRx is cleared). The peripheral events will be determined by the action output on the port pin.
When the device enters the "RESET state", the Data Direction registers (DDR) are forced set, which will make the I/O hi-impedance inputs. The RESET state of some peripheral modules may force the I/O to other operations, such as analog inputs or the system bus.
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10.1 PORTA Register
PORTA is a 6-bit wide latch. PORTA does not have a corresponding Data Direction Register (DDR). Upon a device RESET, the PORTA pins are forced to be hiimpedance inputs. For the RA4 and RA5 pins, the peripheral module controls the output. When a device RESET occurs, the peripheral module is disabled, so these pins are forced to be hi-impedance inputs. Reading PORTA reads the status of the pins. The RA0 pin is multiplexed with the external interrupt, INT. The RA1 pin is multiplexed with TMR0 clock input, RA2 and RA3 are multiplexed with the SSP functions, and RA4 and RA5 are multiplexed with the USART1 functions. The control of RA2, RA3, RA4 and RA5 as outputs, is automatically configured by their multiplexed peripheral module when the module is enabled. Example 10-1 shows an instruction sequence to initialize PORTA. The Bank Select Register (BSR) must be selected to Bank 0 for the port to be initialized. The following example uses the MOVLB instruction to load the BSR register for bank selection.
EXAMPLE 10-1:
MOVLB MOVLW MOVWF 0 0xF3 PORTA
INITIALIZING PORTA
; Select Bank 0 ; ; Initialize PORTA ; RA<3:2> are output low ; RA<5:4> and RA<1:0> ; are inputs ; (outputs floating)
FIGURE 10-1:
10.1.1
USING RA2, RA3 AS OUTPUTS
RA0 AND RA1 BLOCK DIAGRAM
The RA2 and RA3 pins are open drain outputs. To use the RA2 and/or the RA3 pin(s) as output(s), simply write to the PORTA register the desired value. A '0' will cause the pin to drive low, while a '1' will cause the pin to float (hi-impedance). An external pull-up resistor should be used to pull the pin high. Writes to the RA2 and RA3 pins will not affect the other PORTA pins. Note: When using the RA2 or RA3 pin(s) as output(s), read-modify-write instructions (such as BCF, BSF, BTG) on PORTA are not recommended. Such operations read the port pins, do the desired operation, and then write this value to the data latch. This may inadvertently cause the RA2 or RA3 pins to switch from input to output (or vice-versa). To avoid this possibility, use a shadow register for PORTA. Do the bit operations on this shadow register and then move it to PORTA.
Data Bus
RD_PORTA (Q2) Note: Input pins have protection diodes to VDD and VSS.
FIGURE 10-2:
RA2 BLOCK DIAGRAM
Peripheral Data In D EN Q Data Bus
RD_PORTA (Q2) Q D
1 0
Q
CK
WR_PORTA (Q4) SCL Out I2C Mode Enable
Note: I/O pin has protection diodes to VSS.
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PIC17C7XX
FIGURE 10-3: RA3 BLOCK DIAGRAM
Peripheral Data In D EN Q Data Bus Data Bus
FIGURE 10-4:
RA4 AND RA5 BLOCK DIAGRAM
Serial Port Input Signal
RD_PORTA (Q2) Q D
RD_PORTA (Q2) Serial Port Output Signals
Q
CK
WR_PORTA (Q4) SDA Out
OE = SPEN,SYNC,TXEN, CREN, SREN for RA4 OE = SPEN (SYNC+SYNC, CSRC) for RA5
'1' Note: I/O pins have protection diodes to VDD and VSS. SSP Mode Note: I/O pin has protection diodes to VSS.
TABLE 10-1:
Name RA0/INT RA1/T0CKI RA2/SS/SCL RA3/SDI/SDA RA4/RX1/DT1 RA5/TX1/CK1 RBPU
PORTA FUNCTIONS
Bit0 bit0 bit1 bit2 bit3 bit4 bit5 bit7 Buffer Type ST ST ST ST ST ST -- Input or external interrupt input. Input or clock input to the TMR0 timer/counter and/or an external interrupt input. Input/output or slave select input for the SPI, or clock input for the I2C bus. Output is open drain type. Input/output or data input for the SPI, or data for the I2C bus. Output is open drain type. Input or USART1 Asynchronous Receive input, or USART1 Synchronous Data input/output. Input or USART1 Asynchronous Transmit output, or USART1 Synchronous Clock input/output. Control bit for PORTB weak pull-ups. Function
Legend: ST = Schmitt Trigger input
TABLE 10-2:
Address
REGISTERS/BITS ASSOCIATED WITH PORTA
Name Bit 7 Bit 6 Bit 5 RA5/ TX1/CK1 T0CS SREN TXEN Bit 4 RA4/ RX1/DT1 T0PS3 CREN SYNC Bit 3 RA3/ SDI/SDA T0PS2 -- -- Bit 2 RA2/ SS/SCL T0PS1 FERR -- Bit 1 Bit 0 Value on POR, BOR
0-xx 11xx 0000 0000000 -00x 0000 --1x
MCLR, WDT
10h, Bank 0 05h, Unbanked 13h, Bank 0 15h, Bank 0
PORTA(1) T0STA RCSTA1 TXSTA1
RBPU INTEDG SPEN CSRC
-- T0SE RX9 TX9
RA1/T0CKI T0PS0 OERR TRMT
RA0/INT -- RX9D TX9D
0-uu 11uu 0000 0000000 -00u 0000 --1u
Legend: x = unknown, u = unchanged, - = unimplemented, reads as '0'. Shaded cells are not used by PORTA. Note 1: On any device RESET, these pins are configured as inputs.
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DS30289B-page 73
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10.2 PORTB and DDRB Registers
PORTB is an 8-bit wide, bi-directional port. The corresponding data direction register is DDRB. A '1' in DDRB configures the corresponding port pin as an input. A '0' in the DDRB register configures the corresponding port pin as an output. Reading PORTB reads the status of the pins, whereas writing to PORTB will write to the port latch. Each of the PORTB pins has a weak internal pull-up. A single control bit can turn on all the pull-ups. This is done by clearing the RBPU (PORTA<7>) bit. The weak pull-up is automatically turned off when the port pin is configured as an output. The pull-ups are enabled on any RESET. PORTB also has an interrupt-on-change feature. Only pins configured as inputs can cause this interrupt to occur (i.e., any RB7:RB0 pin configured as an output is excluded from the interrupt-on-change comparison). The input pins (of RB7:RB0) are compared with the value in the PORTB data latch. The "mismatch" outputs of RB7:RB0 are OR'd together to set the PORTB Interrupt Flag bit, RBIF (PIR1<7>). This interrupt can wake the device from SLEEP. The user, in the Interrupt Service Routine, can clear the interrupt by: a) b) Read-Write PORTB (such as: MOVPF PORTB, PORTB). This will end the mismatch condition. Then, clear the RBIF bit.
A mismatch condition will continue to set the RBIF bit. Reading, then writing PORTB, will end the mismatch condition and allow the RBIF bit to be cleared. This interrupt-on-mismatch feature, together with software configurable pull-ups on this port, allows easy interface to a keypad and makes it possible for wakeup on key depression. For an example, refer to Application Note AN552, "Implementing Wake-up on Keystroke." The interrupt-on-change feature is recommended for wake-up on operations, where PORTB is only used for the interrupt-on-change feature and key depression operations. Note: On a device RESET, the RBIF bit is indeterminate, since the value in the latch may be different than the pin.
FIGURE 10-5:
BLOCK DIAGRAM OF RB5:RB4 AND RB1:RB0 PORT PINS
Peripheral Data In RBPU (PORTA<7>)
Weak Pull-up
Match Signal from other port pins Port Input Latch
RBIF
Data Bus
RD_DDRB (Q2)
RD_PORTB (Q2) D OE Q CK D Port Data Note: I/O pins have protection diodes to VDD and VSS. Q CK WR_PORTB (Q4) WR_DDRB (Q4)
DS30289B-page 74
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PIC17C7XX
Example 10-2 shows an instruction sequence to initialize PORTB. The Bank Select Register (BSR) must be selected to Bank 0 for the port to be initialized. The following example uses the MOVLB instruction to load the BSR register for bank selection.
EXAMPLE 10-2:
MOVLB CLRF MOVLW MOVWF 0 PORTB, F 0xCF DDRB ; ; ; ; ; ; ; ;
INITIALIZING PORTB
Select Bank 0 Init PORTB by clearing output data latches Value used to initialize data direction Set RB<3:0> as inputs RB<5:4> as outputs RB<7:6> as inputs
FIGURE 10-6:
BLOCK DIAGRAM OF RB3:RB2 PORT PINS
Peripheral Data In RBPU (PORTA<7>)
Weak Pull-up
Match Signal from other port pins RBIF Port Input Latch Data Bus
RD_DDRB (Q2)
RD_PORTB (Q2) D OE Q CK D Port Data Q CK R WR_PORTB (Q4) WR_DDRB (Q4)
Peripheral_output Peripheral_enable Note: I/O pins have protection diodes to VDD and VSS.
2000 Microchip Technology Inc.
DS30289B-page 75
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FIGURE 10-7: BLOCK DIAGRAM OF RB6 PORT PIN
Peripheral Data In RBPU (PORTA<7>) Weak Pull-up Match Signal from other port pins RBIF
D EN
Q
Data Bus
RD_DDRB (Q2)
RD_PORTB (Q2)
OE
D Q WR_DDRB (Q4) CK Port Data Q 1 Q CK WR_PORTB (Q4) SPI Output SPI Output Enable D
P
0
N
Note: I/O pin has protection diodes to Vdd and Vss.
FIGURE 10-8:
BLOCK DIAGRAM OF RB7 PORT PIN
Peripheral Data In RBPU (PORTA<7>)
Weak Pull-up
Match Signal from other port pins RBIF
D EN
Q
Data Bus
RD_DDRB (Q2)
RD_PORTB (Q2) D OE Q WR_DDRB (Q4) CK P Port Data Q 1 N Q CK D WR_PORTB (Q4) SPI Output SPI Output Enable Note: I/O pin has protection diodes to VDD and VSS.
0
SS Output Disable
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PIC17C7XX
TABLE 10-3:
Name RB0/CAP1 RB1/CAP2 RB2/PWM1 RB3/PWM2 RB4/TCLK12 RB5/TCLK3 RB6/SCK RB7/SDO
PORTB FUNCTIONS
Bit bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7 Buffer Type ST ST ST ST ST ST ST ST Function Input/output or the Capture1 input pin. Software programmable weak pull-up and interrupt-on-change features. Input/output or the Capture2 input pin. Software programmable weak pull-up and interrupt-on-change features. Input/output or the PWM1 output pin. Software programmable weak pull-up and interrupt-on-change features. Input/output or the PWM2 output pin. Software programmable weak pull-up and interrupt-on-change features. Input/output or the external clock input to Timer1 and Timer2. Software programmable weak pull-up and interrupt-on-change features. Input/output or the external clock input to Timer3. Software programmable weak pull-up and interrupt-on-change features. Input/output or the Master/Slave clock for the SPI. Software programmable weak pull-up and interrupt-on-change features. Input/output or data output for the SPI. Software programmable weak pull-up and interrupt-on-change features.
Legend: ST = Schmitt Trigger input
TABLE 10-4:
Address 12h, Bank 0 11h, Bank 0 10h, Bank 0 06h, Unbanked 07h, Unbanked 16h, Bank 1 17h, Bank 1 16h, Bank 3 17h, Bank 3
Legend:
REGISTERS/BITS ASSOCIATED WITH PORTB
Name Bit 7 RB7/ SDO Bit 6 RB6/ SCK Bit 5 RB5/ TCLK3 Bit 4 RB4/ TCLK12 Bit 3 RB3/ PWM2 Bit 2 RB2/ PWM1 Bit 1 RB1/ CAP2 Bit 0 RB0/ CAP1 Value on POR, BOR MCLR, WDT
PORTB DDRB PORTA CPUSTA INTSTA PIR1 PIE1 TCON1 TCON2
xxxx xxxx uuuu uuuu 1111 1111 1111 1111
Data Direction Register for PORTB RBPU -- PEIF RBIF RBIE -- -- T0CKIF TMR3IF TMR3IE RA5/ TX1/CK1 STKAV T0IF TMR2IF TMR2IE CA1ED1 RA4/ RX1/DT1 GLINTD INTF TMR1IF TMR1IE CA1ED0 RA3/ SDI/SDA TO PEIE CA2IF CA2IE T16 RA2/ SS/SCL PD T0CKIE CA1IF CA1IE TMR3CS RA1/T0CKI POR T0IE TX1IF TX1IE TMR2CS TMR2ON RA0/INT BOR INTE RC1IF RC1IE
0-xx 11xx 0-uu 11uu --11 11qq --11 qquu 0000 0000 0000 0000 x000 0010 u000 0010 0000 0000 0000 0000
CA2ED1 CA2ED0
TMR1CS 0000 0000 0000 0000 TMR1ON 0000 0000 0000 0000
CA2OVF CA1OVF PWM2ON PWM1ON CA1/PR3 TMR3ON
x = unknown, u = unchanged, - = unimplemented, read as '0', q = value depends on condition. Shaded cells are not used by PORTB.
2000 Microchip Technology Inc.
DS30289B-page 77
PIC17C7XX
10.3 PORTC and DDRC Registers
PORTC is an 8-bit bi-directional port. The corresponding data direction register is DDRC. A '1' in DDRC configures the corresponding port pin as an input. A '0' in the DDRC register configures the corresponding port pin as an output. Reading PORTC reads the status of the pins, whereas writing to PORTC will write to the port latch. PORTC is multiplexed with the system bus. When operating as the system bus, PORTC is the low order byte of the address/data bus (AD7:AD0). The timing for the system bus is shown in the Electrical Specifications section. Note: This port is configured as the system bus when the device's configuration bits are selected to Microprocessor or Extended Microcontroller modes. In the two other microcontroller modes, this port is a general purpose I/O. Example 10-3 shows an instruction sequence to initialize PORTC. The Bank Select Register (BSR) must be selected to Bank 1 for the port to be initialized. The following example uses the MOVLB instruction to load the BSR register for bank selection.
EXAMPLE 10-3:
MOVLB CLRF 1 PORTC, F ; ; ; ; ; ; ; ; ;
INITIALIZING PORTC
Select Bank 1 Initialize PORTC data latches before setting the data direction reg Value used to initialize data direction Set RC<3:0> as inputs RC<5:4> as outputs RC<7:6> as inputs
MOVLW MOVWF
0xCF DDRC
FIGURE 10-9:
BLOCK DIAGRAM OF RC7:RC0 PORT PINS
To D_Bus IR INSTRUCTION READ Data Bus TTL Input Buffer
RD_PORTC
0 1
Port Data
Q CK
D WR_PORTC
Q CK S
D
RD_DDRC WR_DDRC
R
EX_EN DATA/ADDR_OUT DRV_SYS System Bus Control
Note: I/O pins have protection diodes to VDD and VSS.
DS30289B-page 78
2000 Microchip Technology Inc.
PIC17C7XX
TABLE 10-5:
Name RC0/AD0 RC1/AD1 RC2/AD2 RC3/AD3 RC4/AD4 RC5/AD5 RC6/AD6 RC7/AD7
PORTC FUNCTIONS
Bit bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7 Buffer Type TTL TTL TTL TTL TTL TTL TTL TTL Function Input/output or system bus address/data pin. Input/output or system bus address/data pin. Input/output or system bus address/data pin. Input/output or system bus address/data pin. Input/output or system bus address/data pin. Input/output or system bus address/data pin. Input/output or system bus address/data pin. Input/output or system bus address/data pin.
Legend: TTL = TTL input
TABLE 10-6:
Address 11h, Bank 1 10h, Bank 1
REGISTERS/BITS ASSOCIATED WITH PORTC
Bit 7 RC7/ AD7 Bit 6 RC6/ AD6 Bit 5 RC5/ AD5 Bit 4 RC4/ AD4 Bit 3 RC3/ AD3 Bit 2 RC2/ AD2 Bit 1 RC1/ AD1 Bit 0 RC0/ AD0 Value on POR, BOR MCLR, WDT
Name PORTC DDRC
xxxx xxxx uuuu uuuu 1111 1111 1111 1111
Data Direction Register for PORTC
Legend: x = unknown, u = unchanged
2000 Microchip Technology Inc.
DS30289B-page 79
PIC17C7XX
10.4 PORTD and DDRD Registers
PORTD is an 8-bit bi-directional port. The corresponding data direction register is DDRD. A '1' in DDRD configures the corresponding port pin as an input. A '0' in the DDRD register configures the corresponding port pin as an output. Reading PORTD reads the status of the pins, whereas writing to PORTD will write to the port latch. PORTD is multiplexed with the system bus. When operating as the system bus, PORTD is the high order byte of the address/data bus (AD15:AD8). The timing for the system bus is shown in the Electrical Specifications section. Note: This port is configured as the system bus when the device's configuration bits are selected to Microprocessor or Extended Microcontroller modes. In the two other microcontroller modes, this port is a general purpose I/O. Example 10-4 shows an instruction sequence to initialize PORTD. The Bank Select Register (BSR) must be selected to Bank 1 for the port to be initialized. The following example uses the MOVLB instruction to load the BSR register for bank selection.
EXAMPLE 10-4:
MOVLB CLRF 1 PORTD, F ; ; ; ; ; ; ; ; ;
INITIALIZING PORTD
Select Bank 1 Initialize PORTD data latches before setting the data direction reg Value used to initialize data direction Set RD<3:0> as inputs RD<5:4> as outputs RD<7:6> as inputs
MOVLW MOVWF
0xCF DDRD
FIGURE 10-10:
BLOCK DIAGRAM OF RD7:RD0 PORT PINS (IN I/O PORT MODE)
To D_Bus IR INSTRUCTION READ
Data Bus TTL Input Buffer
RD_PORTD
0 1
Port Data
Q CK
D WR_PORTD
Q CK S
D
RD_DDRD WR_DDRD
R
EX_EN DATA/ADDR_OUT DRV_SYS System Bus Control
Note: I/O pins have protection diodes to VDD and VSS.
DS30289B-page 80
2000 Microchip Technology Inc.
PIC17C7XX
TABLE 10-7:
Name RD0/AD8 RD1/AD9 RD2/AD10 RD3/AD11 RD4/AD12 RD5/AD13 RD6/AD14 RD7/AD15
PORTD FUNCTIONS
Bit bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7 Buffer Type TTL TTL TTL TTL TTL TTL TTL TTL Function Input/output or system bus address/data pin. Input/output or system bus address/data pin. Input/output or system bus address/data pin. Input/output or system bus address/data pin. Input/output or system bus address/data pin. Input/output or system bus address/data pin. Input/output or system bus address/data pin. Input/output or system bus address/data pin.
Legend: TTL = TTL input
TABLE 10-8:
Address
REGISTERS/BITS ASSOCIATED WITH PORTD
Bit 7 RD7/ AD15 Bit 6 RD6/ AD14 Bit 5 RD5/ AD13 Bit 4 RD4/ AD12 Bit 3 RD3/ AD11 Bit 2 RD2/ AD10 Bit 1 RD1/ AD9 Bit 0 RD0/ AD8 Value on POR, BOR MCLR, WDT
Name
13h, Bank 1 PORTD 12h, Bank 1 DDRD
xxxx xxxx uuuu uuuu 1111 1111 1111 1111
Data Direction Register for PORTD
Legend: x = unknown, u = unchanged
2000 Microchip Technology Inc.
DS30289B-page 81
PIC17C7XX
10.5 PORTE and DDRE Register
PORTE is a 4-bit bi-directional port. The corresponding data direction register is DDRE. A '1' in DDRE configures the corresponding port pin as an input. A '0' in the DDRE register configures the corresponding port pin as an output. Reading PORTE reads the status of the pins, whereas writing to PORTE will write to the port latch. PORTE is multiplexed with the system bus. When operating as the system bus, PORTE contains the control signals for the address/data bus (AD15:AD0). These control signals are Address Latch Enable (ALE), Output Enable (OE) and Write (WR). The control signals OE and WR are active low signals. The timing for the system bus is shown in the Electrical Specifications section. Note: Three pins of this port are configured as the system bus when the device's configuration bits are selected to Microprocessor or Extended Microcontroller modes. The other pin is a general purpose I/O or Capture4 pin. In the two other microcontroller modes, RE2:RE0 are general purpose I/O pins. Example 10-5 shows an instruction sequence to initialize PORTE. The Bank Select Register (BSR) must be selected to Bank 1 for the port to be initialized. The following example uses the MOVLB instruction to load the BSR register for bank selection.
EXAMPLE 10-5:
MOVLB CLRF 1 PORTE, F ; ; ; ; ; ; ; ; ; ; ;
INITIALIZING PORTE
Select Bank 1 Initialize PORTE data latches before setting the data direction register Value used to initialize data direction Set RE<1:0> as inputs RE<3:2> as outputs RE<7:4> are always read as '0'
MOVLW MOVWF
0x03 DDRE
FIGURE 10-11:
BLOCK DIAGRAM OF RE2:RE0 (IN I/O PORT MODE)
Data Bus TTL Input Buffer
RD_PORTE
0 1
Port Data
Q CK
D WR_PORTE
Q CK S
D
RD_DDRE WR_DDRE
R
EX_EN CNTL DRV_SYS Note: I/O pins have protection diodes to VDD and VSS. System Bus Control
DS30289B-page 82
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 10-12: BLOCK DIAGRAM OF RE3/CAP4 PORT PIN
Peripheral In
D EN EN
Q
Data Bus
VDD P Q Port Data N Q CK D
RD_PORTE
WR_PORTE
Q CK S
D
RD_DDRE WR_DDRE
Q
Note: I/O pin has protection diodes to VDD and VSS.
TABLE 10-9:
Name RE0/ALE RE1/OE RE2/WR RE3/CAP4
PORTE FUNCTIONS
Bit bit0 bit1 bit2 bit3 Buffer Type TTL TTL TTL ST Function Input/output or system bus Address Latch Enable (ALE) control pin. Input/output or system bus Output Enable (OE) control pin. Input/output or system bus Write (WR) control pin. Input/output or Capture4 input pin.
Legend: TTL = TTL input, ST = Schmitt Trigger input
TABLE 10-10: REGISTERS/BITS ASSOCIATED WITH PORTE
Address 15h, Bank 1 14h, Bank 1 14h, Bank 7 15h, Bank 7 16h, Bank 7 Legend: Name PORTE DDRE CA4L CA4H TCON3 Bit 7 -- Bit 6 -- Bit 5 -- Bit 4 -- Bit 3 RE3/CAP4 Bit 2 RE2/WR Bit 1 RE1/OE Bit 0 RE0/ALE Value on POR, BOR
---- xxxx ---- 1111 xxxx xxxx xxxx xxxx
MCLR, WDT
---- uuuu ---- 1111 uuuu uuuu uuuu uuuu -000 0000
Data Direction Register for PORTE Capture4 Low Byte Capture4 High Byte -- CA4OVF CA3OVF CA4ED1 CA4ED0 CA3ED1 CA3ED0 PWM3ON
-000 0000
x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PORTE.
2000 Microchip Technology Inc.
DS30289B-page 83
PIC17C7XX
10.6 PORTF and DDRF Registers
PORTF is an 8-bit wide bi-directional port. The corresponding data direction register is DDRF. A '1' in DDRF configures the corresponding port pin as an input. A '0' in the DDRF register configures the corresponding port pin as an output. Reading PORTF reads the status of the pins, whereas writing to PORTF will write to the respective port latch. All eight bits of PORTF are multiplexed with 8 channels of the 10-bit A/D converter. Upon RESET, the entire Port is automatically configured as analog inputs and must be configured in software to be a digital I/O.
MOVLW MOVWF 0x03 DDRF
Example 10-6 shows an instruction sequence to initialize PORTF. The Bank Select Register (BSR) must be selected to Bank 5 for the port to be initialized. The following example uses the MOVLB instruction to load the BSR register for bank selection.
EXAMPLE 10-6:
MOVLB MOVWF MOVWF CLRF 5 0x0E ADCON1 PORTF, F
INITIALIZING PORTF
; ; ; ; ; ; ; ; ; ; ; Select Bank 5 Configure PORTF as Digital Initialize PORTF data latches before the data direction register Value used to init data direction Set RF<1:0> as inputs RF<7:2> as outputs
FIGURE 10-13:
Data Bus WR PORTF
BLOCK DIAGRAM OF RF7:RF0
D CK Q VDD Q P
Data Latch I/O pin D WR DDRF CK Q Q N VSS
DDRF Latch ST Input Buffer Q D EN EN RD PORTF
RD DDRF
PCFG3:PCFG0 VAIN
To other pads
CHS3:CHS0
To other pads
Note: I/O pins have protection diodes to VDD and VSS.
DS30289B-page 84
2000 Microchip Technology Inc.
PIC17C7XX
TABLE 10-11: PORTF FUNCTIONS
Name RF0/AN4 RF1/AN5 RF2/AN6 RF3/AN7 RF4/AN8 RF5/AN9 RF6/AN10 RF7/AN11 Bit bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7 Buffer Type ST ST ST ST ST ST ST ST Input/output or analog input 4. Input/output or analog input 5. Input/output or analog input 6. Input/output or analog input 7. Input/output or analog input 8. Input/output or analog input 9. Input/output or analog input 10. Input/output or analog input 11. Function
Legend: ST = Schmitt Trigger input
TABLE 10-12: REGISTERS/BITS ASSOCIATED WITH PORTF
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR MCLR, WDT
10h, Bank 5 DDRF 11h, Bank 5 PORTF
Data Direction Register for PORTF RF7/ AN11 RF6/ AN10 RF5/ AN9 ADFM RF4/ AN8 -- RF3/ AN7 PCFG3 RF2/ AN6 PCFG2 RF1/ AN5 PCFG1 RF0/ AN4
1111 1111 1111 1111 0000 0000 0000 0000
15h, Bank 5 ADCON1 ADCS1 ADCS0
PCFG0 000- 0000 000- 0000
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PORTF.
2000 Microchip Technology Inc.
DS30289B-page 85
PIC17C7XX
10.7 PORTG and DDRG Registers
PORTG is an 8-bit wide, bi-directional port. The corresponding data direction register is DDRG. A '1' in DDRG configures the corresponding port pin as an input. A '0' in the DDRG register configures the corresponding port pin as an output. Reading PORTG reads the status of the pins, whereas writing to PORTG will write to the port latch. The lower four bits of PORTG are multiplexed with four channels of the 10-bit A/D converter. The remaining bits of PORTG are multiplexed with peripheral output and inputs. RG4 is multiplexed with the CAP3 input, RG5 is multiplexed with the PWM3 output, RG6 and RG7 are multiplexed with the USART2 functions. Upon RESET, RG3:RG0 is automatically configured as analog inputs and must be configured in software to be a digital I/O. Example 10-7 shows the instruction sequence to initialize PORTG. The Bank Select Register (BSR) must be selected to Bank 5 for the port to be initialized. The following example uses the MOVLB instruction to load the BSR register for bank selection.
EXAMPLE 10-7:
MOVLB MOVLW MOVPF CLRF
INITIALIZING PORTG
MOVLW MOVWF
5 ; Select Bank 5 0x0E ; Configure PORTG as WREG, ADCON1 ; digital PORTG, F ; Initialize PORTG data ; latches before ; the data direction ; register 0x03 ; Value used to init ; data direction DDRG ; Set RG<1:0> as inputs ; RG<7:2> as outputs
FIGURE 10-14:
Data Bus WR PORTG
BLOCK DIAGRAM OF RG3:RG0
D CK Q VDD Q P
Data Latch I/O pin D WR DDRG CK Q Q N VSS
DDRG Latch ST Input Buffer Q D EN EN RD PORTG
RD DDRG
PCFG3:PCFG0 VAIN
To other pads
CHS3:CHS0
To other pads
Note: I/O pins have protection diodes to VDD and VSS.
DS30289B-page 86
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 10-15: RG4 BLOCK DIAGRAM
Peripheral Data In
D EN EN
Q
Data Bus
RD_PORTG
VDD P Q CK
D WR_PORTG
Q N Q CK
D
RD_DDRG WR_DDRG
Note: I/O pins have protection diodes to VDD and VSS.
FIGURE 10-16:
RG7:RG5 BLOCK DIAGRAM
Peripheral Data In D EN N Q Data Bus
RD_PORTG
VDD 1 P 0
Port Data
Q Q CK
D WR_PORTG
Q N Q CK R
D
RD_DDRG WR_DDRG
OUTPUT OUTPUT ENABLE Note: I/O pins have protection diodes to VDD and VSS.
2000 Microchip Technology Inc.
DS30289B-page 87
PIC17C7XX
TABLE 10-13: PORTG FUNCTIONS
Name RG0/AN3 RG1/AN2 RG2/AN1/VREFRG3/AN0/VREF+ RG4/CAP3 RG5/PWM3 RG6/RX2/DT2 RG7/TX2/CK2 Bit bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7 Buffer Type ST ST ST ST ST ST ST ST Input/output or analog input 3. Input/output or analog input 2. Input/output or analog input 1 or the ground reference voltage. Input/output or analog input 0 or the positive reference voltage. Input/output or the Capture3 input pin. Input/output or the PWM3 output pin. Input/output or the USART2 (SCI) Asynchronous Receive or USART2 (SCI) Synchronous Data. Input/output or the USART2 (SCI) Asynchronous Transmit or USART2 (SCI) Synchronous Clock. Function
Legend: ST = Schmitt Trigger input
TABLE 10-14: REGISTERS/BITS ASSOCIATED WITH PORTG
Address 12h, Bank 5 13h, Bank 5 15h, Bank 5 Legend: Name DDRG PORTG ADCON1 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR
1111 1111
MCLR, WDT
Data Direction Register for PORTG RG7/ TX2/CK2 ADCS1 RG6/ RX2/DT2 ADCS0 RG5/ PWM3 ADFM RG4/ CAP3 -- RG3/ AN0 PCFG3 RG2/ AN1 PCFG2 RG1/ AN2 PCFG1 RG0/ AN3 PCFG0
1111 1111 uuuu 0000 000- 0000
xxxx 0000 000- 0000
x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by PORTG.
DS30289B-page 88
2000 Microchip Technology Inc.
PIC17C7XX
10.8 PORTH and DDRH Registers (PIC17C76X only)
EXAMPLE 10-8:
MOVLB MOVLW MOVPF CLRF 8 0x0E ADCON1 PORTH, F
INITIALIZING PORTH
; ; ; ; ; ; ; ; ; ; ; Select Bank 8 Configure PORTH as digital Initialize PORTH data latches before the data direction register Value used to init data direction Set RH<1:0> as inputs RH<7:2> as outputs
PORTH is an 8-bit wide, bi-directional port. The corresponding data direction register is DDRH. A '1' in DDRH configures the corresponding port pin as an input. A '0' in the DDRH register configures the corresponding port pin as an output. Reading PORTH reads the status of the pins, whereas writing to PORTH will write to the respective port latch. The upper four bits of PORTH are multiplexed with 4 channels of the 10-bit A/D converter. The remaining bits of PORTH are general purpose I/O. Upon RESET, RH7:RH4 are automatically configured as analog inputs and must be configured in software to be a digital I/O.
MOVLW MOVWF
0x03 DDRH
FIGURE 10-17:
Data Bus WR PORTH
BLOCK DIAGRAM OF RH7:RH4
D CK Q VDD Q P
Data Latch I/O pin D WR DDRH CK Q Q N VSS
DDRH Latch ST Input Buffer Q D EN EN RD PORT
RD DDRH
PCFG3:PCFG0
To other pads VAIN
CHS3:CHS0
To other pads
Note: I/O pins have protection diodes to VDD and VSS.
2000 Microchip Technology Inc.
DS30289B-page 89
PIC17C7XX
FIGURE 10-18: RH3:RH0 BLOCK DIAGRAM
D EN EN
Q
Data Bus
RD_PORTH
VDD P Q CK
D WR_PORTH
Q N Q CK
D
RD_DDRH WR_DDRH
Note: I/O pins have protection diodes to VDD and VSS.
TABLE 10-15: PORTH FUNCTIONS
Name RH0 RH1 RH2 RH3 RH4/AN12 RH5/AN13 RH6/AN14 RH7/AN15 Bit bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7 Buffer Type ST ST ST ST ST ST ST ST Input/output. Input/output. Input/output. Input/output. Input/output or analog input 12. Input/output or analog input 13. Input/output or analog input 14. Input/output or analog input 15. Function
Legend: ST = Schmitt Trigger input
TABLE 10-16: REGISTERS/BITS ASSOCIATED WITH PORTH
Address 10h, Bank 8 11h, Bank 8 15h, Bank 5 Legend: Name DDRH PORTH ADCON1 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR MCLR, WDT
Data Direction Register for PORTH RH7/ AN15 ADCS1 RH6/ AN14 ADCS0 RH5/ AN13 ADFM RH4/ AN12 -- RH3 PCFG3 RH2 PCFG2 RH1 PCFG1 RH0 PCFG0
1111 1111 1111 1111 0000 xxxx 0000 uuuu 000- 0000 000- 0000
x = unknown, u = unchanged
DS30289B-page 90
2000 Microchip Technology Inc.
PIC17C7XX
10.9 PORTJ and DDRJ Registers (PIC17C76X only)
EXAMPLE 10-9:
MOVLB CLRF 8 PORTJ, F ; ; ; ; ; ; ; ; ; ;
INITIALIZING PORTJ
Select Bank 8 Initialize PORTJ data latches before setting the data direction register Value used to initialize data direction Set RJ<3:0> as inputs RJ<5:4> as outputs RJ<7:6> as inputs
PORTJ is an 8-bit wide, bi-directional port. The corresponding data direction register is DDRJ. A '1' in DDRJ configures the corresponding port pin as an input. A '0' in the DDRJ register configures the corresponding port pin as an output. Reading PORTJ reads the status of the pins, whereas writing to PORTJ will write to the respective port latch. PORTJ is a general purpose I/O port.
MOVLW MOVWF
0xCF DDRJ
FIGURE 10-19:
PORTJ BLOCK DIAGRAM
D EN EN
Q
Data Bus
RD_PORTJ
VDD P Q CK
D WR_PORTJ
Q N Q CK
D
RD_DDRJ WR_DDRJ
Note: I/O pins have protection diodes to VDD and VSS.
2000 Microchip Technology Inc.
DS30289B-page 91
PIC17C7XX
TABLE 10-17: PORTJ FUNCTIONS
Name RJ0 RJ1 RJ2 RJ3 RJ4 RJ5 RJ6 RJ7 Bit bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7 Buffer Type ST ST ST ST ST ST ST ST Input/output Input/output Input/output Input/output Input/output Input/output Input/output Input/output Function
Legend: ST = Schmitt Trigger input
TABLE 10-18: REGISTERS/BITS ASSOCIATED WITH PORTJ
Address 12h, Bank 8 13h, Bank 8 Name DDRJ PORTJ Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on, POR, BOR MCLR, WDT
Data Direction Register for PORTJ RJ7 RJ6 RJ5 RJ4 RJ3 RJ2 RJ1 RJ0
1111 1111 1111 1111 xxxx xxxx uuuu uuuu
Legend: x = unknown, u = unchanged
DS30289B-page 92
2000 Microchip Technology Inc.
PIC17C7XX
10.10 I/O Programming Considerations
10.10.1 BI-DIRECTIONAL I/O PORTS EXAMPLE 10-10: READ-MODIFY-WRITE INSTRUCTIONS ON AN I/O PORT
Any instruction which writes, operates internally as a read, followed by a write operation. For example, the BCF and BSF instructions read the register into the CPU, execute the bit operation and write the result back to the register. Caution must be used when these instructions are applied to a port with both inputs and outputs defined. For example, a BSF operation on bit5 of PORTB, will cause all eight bits of PORTB to be read into the CPU. Then the BSF operation takes place on bit5 and PORTB is written to the output latches. If another bit of PORTB is used as a bi-directional I/O pin (e.g. bit0) and it is defined as an input at this time, the input signal present on the pin itself would be read into the CPU and rewritten to the data latch of this particular pin, overwriting the previous content. As long as the pin stays in the input mode, no problem occurs. However, if bit0 is switched into output mode later on, the content of the data latch may now be unknown. Reading a port reads the values of the port pins. Writing to the port register writes the value to the port latch. When using read-modify-write instructions (BCF, BSF, BTG, etc.) on a port, the value of the port pins is read, the desired operation is performed with this value and the value is then written to the port latch. Example 10-10 shows the possible effect of two sequential read-modify-write instructions on an I/O port.
; Initial PORT settings: PORTB<7:4> Inputs ; PORTB<3:0> Outputs ; PORTB<7:6> have pull-ups and are ; not connected to other circuitry ; ; PORT latch PORT pins ; ---------- --------; BCF PORTB, 7 ; 01pp pppp 11pp pppp BCF PORTB, 6 ; 10pp pppp 11pp pppp BCF BCF ; ; ; ; ; DDRB, 7 DDRB, 6 ; 10pp pppp ; 10pp pppp 11pp pppp 10pp pppp
Note that the user may have expected the pin values to be 00pp pppp. The 2nd BCF caused RB7 to be latched as the pin value (High).
Note:
A pin actively outputting a Low or High should not be driven from external devices, in order to change the level on this pin (i.e., "wired-or", "wired-and"). The resulting high output currents may damage the device.
2000 Microchip Technology Inc.
DS30289B-page 93
PIC17C7XX
10.10.2 SUCCESSIVE OPERATIONS ON I/O PORTS
Figure 10-21 shows the I/O model which causes this situation. As the effective capacitance (C) becomes larger, the rise/fall time of the I/O pin increases. As the device frequency increases, or the effective capacitance increases, the possibility of this subsequent PORTx read-modify-write instruction issue increases. This effective capacitance includes the effects of the board traces. The best way to address this is to add a series resistor at the I/O pin. This resistor allows the I/O pin to get to the desired level before the next instruction. The use of NOP instructions between the subsequent PORTx read-modify-write instructions, is a lower cost solution, but has the issue that the number of NOP instructions is dependent on the effective capacitance C and the frequency of the device.
The actual write to an I/O port happens at the end of an instruction cycle, whereas for reading, the data must be valid at the beginning of the instruction cycle (Figure 10-20). Therefore, care must be exercised if a write followed by a read operation is carried out on the same I/O port. The sequence of instructions should be such to allow the pin voltage to stabilize (load dependent) before executing the instruction that reads the values on that I/O port. Otherwise, the previous state of that pin may be read into the CPU, rather than the "new" state. When in doubt, it is better to separate these instructions with a NOP, or another instruction not accessing this I/O port.
FIGURE 10-20:
SUCCESSIVE I/O OPERATION
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 PC PC + 1
MOVF PORTB,W NOP NOP
Q1 Q2 Q3 Q4 Note: PC + 3 This example shows a write to PORTB, followed by a read from PORTB. Note that: data setup time = (0.25TCY - TPD) where TCY = instruction cycle TPD = propagation delay
PC + 2
Instruction Fetched
MOVWF PORTB write to PORTB
RB7:RB0 Port pin sampled here Instruction Executed
MOVWF PORTB write to PORTB MOVF PORTB,W NOP
Therefore, at higher clock frequencies, a write followed by a read may be problematic.
FIGURE 10-21:
PIC17CXXX
I/O
I/O CONNECTION ISSUES
BSF PORTx, PINy Q2 VIL C(1) PORTx, PINy Read PORTx, PINy as low Q3 Q4 Q1 BSF PORTx, PINz Q2 Q3 Q4 Q1
Note 1: This is not a capacitor to ground, but the effective capacitive loading on the trace.
BSF PORTx, PINz clears the value to be driven on the PORTx, PINy pin.
DS30289B-page 94
2000 Microchip Technology Inc.
PIC17C7XX
11.0 OVERVIEW OF TIMER RESOURCES
11.3 Timer2 Overview
The Timer2 module is an 8-bit timer/counter with an 8bit period register (PR2). When the TMR2 value rolls over from the period match value to 0h, the TMR2IF flag is set and an interrupt will be generated, if enabled. In Counter mode, the clock comes from the RB4/ TCLK12 pin, which can also provide the clock for the Timer1 module. TMR2 can be concatenated with TMR1 to form a 16-bit timer. The TMR2 register is the MSB and TMR1 is the LSB. When in the 16-bit timer mode, there is a corresponding 16-bit period register (PR2:PR1). When the TMR2:TMR1 value rolls over from the period match value to 0h, the TMR1IF flag is set and an interrupt will be generated, if enabled.
The PIC17C7XX has four timer modules. Each module can generate an interrupt to indicate that an event has occurred. These timers are called: * Timer0 - 16-bit timer with programmable 8-bit prescaler * Timer1 - 8-bit timer * Timer2 - 8-bit timer * Timer3 - 16-bit timer For enhanced time base functionality, four input Captures and three Pulse Width Modulation (PWM) outputs are possible. The PWMs use the Timer1 and Timer2 resources and the input Captures use the Timer3 resource.
11.4
Timer3 Overview
11.1
Timer0 Overview
The Timer0 module is a simple 16-bit overflow counter. The clock source can be either the internal system clock (Fosc/4) or an external clock. When Timer0 uses an external clock source, it has the flexibility to allow user selection of the incrementing edge, rising or falling. The Timer0 module also has a programmable prescaler. The T0PS3:T0PS0 bits (T0STA<4:1>) determine the prescale value. TMR0 can increment at the following rates: 1:1, 1:2, 1:4, 1:8, 1:16, 1:32, 1:64, 1:128, 1:256. Synchronization of the external clock occurs after the prescaler. When the prescaler is used, the external clock frequency may be higher than the device's frequency. The maximum external frequency on the T0CKI pin is 50 MHz, given the high and low time requirements of the clock.
The Timer3 module is a 16-bit timer/counter with a 16bit period register. When the TMR3H:TMR3L value rolls over to 0h, the TMR3IF bit is set and an interrupt will be generated, if enabled. In Counter mode, the clock comes from the RB5/TCLK3 pin. When operating in the four Capture modes, the period registers become the second (of four) 16-bit capture registers.
11.5
Role of the Timer/Counters
The timer modules are general purpose, but have dedicated resources associated with them. TImer1 and Timer2 are the time bases for the three Pulse Width Modulation (PWM) outputs, while Timer3 is the time base for the four input captures.
11.2
Timer1 Overview
The Timer1 module is an 8-bit timer/counter with an 8bit period register (PR1). When the TMR1 value rolls over from the period match value to 0h, the TMR1IF flag is set and an interrupt will be generated if enabled. In Counter mode, the clock comes from the RB4/ TCLK12 pin, which can also be selected to be the clock for the Timer2 module. TMR1 can be concatenated with TMR2 to form a 16-bit timer. The TMR1 register is the LSB and TMR2 is the MSB. When in the 16-bit timer mode, there is a corresponding 16-bit period register (PR2:PR1). When the TMR2:TMR1 value rolls over from the period match value to 0h, the TMR1IF flag is set and an interrupt will be generated, if enabled.
2000 Microchip Technology Inc.
DS30289B-page 95
PIC17C7XX
NOTES:
DS30289B-page 96
2000 Microchip Technology Inc.
PIC17C7XX
12.0 TIMER0
The Timer0 module consists of a 16-bit timer/counter, TMR0. The high byte is register TMR0H and the low byte is register TMR0L. A software programmable 8-bit prescaler makes Timer0 an effective 24-bit overflow timer. The clock source is software programmable as either the internal instruction clock, or an external clock on the RA1/T0CKI pin. The control bits for this module are in register T0STA (Figure 12-1).
REGISTER 12-1: T0STA REGISTER (ADDRESS: 05h, UNBANKED)
R/W-0 INTEDG bit 7 bit 7 INTEDG: RA0/INT Pin Interrupt Edge Select bit This bit selects the edge upon which the interrupt is detected. 1 = Rising edge of RA0/INT pin generates interrupt 0 = Falling edge of RA0/INT pin generates interrupt T0SE: Timer0 Clock Input Edge Select bit This bit selects the edge upon which TMR0 will increment. When T0CS = 0 (External Clock): 1 = Rising edge of RA1/T0CKI pin increments TMR0 and/or sets the T0CKIF bit 0 = Falling edge of RA1/T0CKI pin increments TMR0 and/or sets the T0CKIF bit When T0CS = 1 (Internal Clock): Don't care bit 5 T0CS: Timer0 Clock Source Select bit This bit selects the clock source for TMR0. 1 = Internal instruction clock cycle (TCY) 0 = External clock input on the T0CKI pin T0PS3:T0PS0: Timer0 Prescale Selection bits These bits select the prescale value for TMR0. T0PS3:T0PS0 Prescale Value 0000 0001 0010 0011 0100 0101 0110 0111 1xxx bit 0 1:1 1:2 1:4 1:8 1:16 1:32 1:64 1:128 1:256 R/W-0 T0SE R/W-0 T0CS R/W-0 T0PS3 R/W-0 T0PS2 R/W-0 T0PS1 R/W-0 T0PS0 U-0 -- bit 0
bit 6
bit 4-1
Unimplemented: Read as '0' Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
2000 Microchip Technology Inc.
DS30289B-page 97
PIC17C7XX
12.1 Timer0 Operation 12.2 Using Timer0 with External Clock
When the T0CS (T0STA<5>) bit is set, TMR0 increments on the internal clock. When T0CS is clear, TMR0 increments on the external clock (RA1/T0CKI pin). The external clock edge can be selected in software. When the T0SE (T0STA<6>) bit is set, the timer will increment on the rising edge of the RA1/T0CKI pin. When T0SE is clear, the timer will increment on the falling edge of the RA1/T0CKI pin. The prescaler can be programmed to introduce a prescale of 1:1 to 1:256. The timer increments from 0000h to FFFFh and rolls over to 0000h. On overflow, the TMR0 Interrupt Flag bit (T0IF) is set. The TMR0 interrupt can be masked by clearing the corresponding TMR0 Interrupt Enable bit (T0IE). The TMR0 Interrupt Flag bit (T0IF) is automatically cleared when vectoring to the TMR0 interrupt vector. When an external clock input is used for Timer0, it is synchronized with the internal phase clocks. Figure 122 shows the synchronization of the external clock. This synchronization is done after the prescaler. The output of the prescaler (PSOUT) is sampled twice in every instruction cycle to detect a rising or a falling edge. The timing requirements for the external clock are detailed in the electrical specification section.
12.2.1
DELAY FROM EXTERNAL CLOCK EDGE
Since the prescaler output is synchronized with the internal clocks, there is a small delay from the time the external clock edge occurs to the time TMR0 is actually incremented. Figure 12-2 shows that this delay is between 3TOSC and 7TOSC. Thus, for example, measuring the interval between two edges (e.g. period) will be accurate within 4TOSC (121 ns @ 33 MHz).
FIGURE 12-1:
TIMER0 MODULE BLOCK DIAGRAM
Interrupt-on-Overflow sets T0IF (INTSTA<5>) 0
RA1/T0CKI T0SE (T0STA<6>)
FOSC/4
1
Prescaler (8 Stage Async Ripple Counter) 4
Synchronization PSOUT
TMR0H<8> TMR0L<8>
T0CS (T0STA<5>)
T0PS3:T0PS0 (T0STA<4:1>)
Q2
Q4
FIGURE 12-2:
TMR0 TIMING WITH EXTERNAL CLOCK (INCREMENT ON FALLING EDGE)
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Prescaler Output (PSOUT) Sampled Prescaler Output (Note 1) Increment TMR0
(Note 3) (Note 2)
TMR0
T0
T0 + 1
T0 + 2
Note 1: The delay from the T0CKI edge to the TMR0 increment is 3Tosc to 7Tosc. 2: = PSOUT is sampled here. 3: The PSOUT high time is too short and is missed by the sampling circuit.
DS30289B-page 98
2000 Microchip Technology Inc.
PIC17C7XX
12.3 Read/Write Consideration for TMR0
12.3.2 WRITING A 16-BIT VALUE TO TMR0
Since writing to either TMR0L or TMR0H will effectively inhibit increment of that half of the TMR0 in the next cycle (following write), but not inhibit increment of the other half, the user must write to TMR0L first and TMR0H second, in two consecutive instructions, as shown in Example 12-2. The interrupt must be disabled. Any write to either TMR0L or TMR0H clears the prescaler.
Although TMR0 is a 16-bit timer/counter, only 8-bits at a time can be read or written during a single instruction cycle. Care must be taken during any read or write.
12.3.1
READING 16-BIT VALUE
The problem in reading the entire 16-bit value is that after reading the low (or high) byte, its value may change from FFh to 00h. Example 12-1 shows a 16-bit read. To ensure a proper read, interrupts must be disabled during this routine.
EXAMPLE 12-2:
BSF MOVFP MOVFP BCF
16-BIT WRITE
; Disable interrupts ; ; ; Done, enable ; interrupts
EXAMPLE 12-1:
MOVPF MOVPF MOVFP CPFSLT RETURN MOVPF MOVPF RETURN
16-BIT READ
;read low tmr0 ;read high tmr0 ;tmplo -> wreg ;tmr0l < wreg? ;no then return ;read low tmr0 ;read high tmr0 ;return
CPUSTA, GLINTD RAM_L, TMR0L RAM_H, TMR0H CPUSTA, GLINTD
TMR0L, TMPLO TMR0H, TMPHI TMPLO, WREG TMR0L TMR0L, TMPLO TMR0H, TMPHI
12.4
Prescaler Assignments
Timer0 has an 8-bit prescaler. The prescaler selection is fully under software control; i.e., it can be changed "on the fly" during program execution. Clearing the prescaler is recommended before changing its setting. The value of the prescaler is "unknown" and assigning a value that is less than the present value, makes it difficult to take this unknown time into account.
FIGURE 12-3:
TMR0 TIMING: WRITE HIGH OR LOW BYTE
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
AD15:AD0
PC
PC+1
PC+2
PC+3
PC+4
ALE T0 T0+1 New T0 (NT0) New T0+1
TMR0L Fetch Instruction Executed TMR0H
MOVFP W,TMR0L MOVFP TMR0L,W MOVFP TMR0L,W MOVFP TMR0L,W Write to TMR0L Read TMR0L Read TMR0L Read TMR0L (Value = NT0) (Value = NT0) (Value = NT0 +1)
2000 Microchip Technology Inc.
DS30289B-page 99
PIC17C7XX
FIGURE 12-4: TMR0 READ/WRITE IN TIMER MODE
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 AD15:AD0 ALE WR_TRM0L WR_TMR0H RD_TMR0L
TMR0H
12
12
13
AB
TMR0L
FE
FF
56
57
58
Instruction Fetched
MOVFP MOVFP DATAL,TMR0L DATAH,TMR0H Write TMR0L Write TMR0H Previously Fetched Instruction
MOVPF TMR0L,W Read TMR0L
MOVPF TMR0L,W Read TMR0L MOVPF TMR0L,W Read TMR0L
MOVPF TMR0L,W Read TMR0L MOVPF TMR0L,W Read TMR0L
MOVPF TMR0L,W Read TMR0L MOVPF TMR0L,W Read TMR0L
Instruction Executed
MOVFP MOVFP DATAL,TMR0L DATAH,TMR0H Write TMR0L Write TMR0H
Note: In this example, old TMR0 value is 12FEh, new value of AB56h is written.
TABLE 12-1:
Address 05h, Unbanked 06h, Unbanked 07h, Unbanked 0Bh, Unbanked 0Ch, Unbanked Legend:
REGISTERS/BITS ASSOCIATED WITH TIMER0
Name T0STA CPUSTA INTSTA TMR0L TMR0H Bit 7 INTEDG -- PEIF Bit 6 T0SE -- T0CKIF Bit 5 T0CS STKAV T0IF Bit 4 T0PS3 GLINTD INTF Bit 3 T0PS2 TO PEIE Bit 2 T0PS1 PD T0CKIE Bit 1 T0PS0 POR T0IE Bit 0 -- BOR INTE Value on POR, BOR
0000 000--11 11qq 0000 0000 xxxx xxxx xxxx xxxx
MCLR, WDT
0000 000--11 qquu 0000 0000 uuuu uuuu uuuu uuuu
TMR0 Register; Low Byte TMR0 Register; High Byte
x = unknown, u = unchanged, - = unimplemented, read as a '0', q = value depends on condition. Shaded cells are not used by Timer0.
DS30289B-page 100
2000 Microchip Technology Inc.
PIC17C7XX
13.0 TIMER1, TIMER2, TIMER3, PWMS AND CAPTURES
Six other registers comprise the Capture2, Capture3, and Capture4 registers (CA2H:CA2L, CA3H:CA3L, and CA4H:CA4L). Figure 13-1, Figure 13-2 and Figure 13-3 are the control registers for the operation of Timer1, Timer2 and Timer3, as well as PWM1, PWM2, PWM3, Capture1, Capture2, Capture3 and Capture4. Table 13-1 shows the Timer resource requirements for these time base functions. Each timer is an open resource so that multiple functions may operate with it. The PIC17C7XX has a wealth of timers and time based functions to ease the implementation of control applications. These time base functions include three PWM outputs and four Capture inputs. Timer1 and Timer2 are two 8-bit incrementing timers, each with an 8-bit period register (PR1 and PR2, respectively) and separate overflow interrupt flags. Timer1 and Timer2 can operate either as timers (increment on internal FOSC/4 clock), or as counters (increment on falling edge of external clock on pin RB4/TCLK12). They are also software configurable to operate as a single 16-bit timer/counter. These timers are also used as the time base for the PWM (Pulse Width Modulation) modules. Timer3 is a 16-bit timer/counter which uses the TMR3H and TMR3L registers. Timer3 also has two additional registers (PR3H/CA1H:PR3L/CA1L) that are configurable as a 16-bit period register or a 16-bit capture register. TMR3 can be software configured to increment from the internal system clock (FOSC/4), or from an external signal on the RB5/TCLK3 pin. Timer3 is the time base for all of the 16-bit captures.
TABLE 13-1:
TIME-BASE FUNCTION/ RESOURCE REQUIREMENTS
Timer Resource Timer1 Timer1 or Timer2 Timer1 or Timer2 Timer3 Timer3 Timer3 Timer3
Time Base Function PWM1 PWM2 PWM3 Capture1 Capture2 Capture3 Capture4
REGISTER 13-1: TCON1 REGISTER (ADDRESS: 16h, BANK 3)
R/W-0 CA2ED1 bit 7 bit 7-6 CA2ED1:CA2ED0: Capture2 Mode Select bits 00 = Capture on every falling edge 01 = Capture on every rising edge 10 = Capture on every 4th rising edge 11 = Capture on every 16th rising edge CA1ED1:CA1ED0: Capture1 Mode Select bits 00 = Capture on every falling edge 01 = Capture on every rising edge 10 = Capture on every 4th rising edge 11 = Capture on every 16th rising edge T16: Timer2:Timer1 Mode Select bit 1 = Timer2 and Timer1 form a 16-bit timer 0 = Timer2 and Timer1 are two 8-bit timers TMR3CS: Timer3 Clock Source Select bit 1 = TMR3 increments off the falling edge of the RB5/TCLK3 pin 0 = TMR3 increments off the internal clock TMR2CS: Timer2 Clock Source Select bit 1 = TMR2 increments off the falling edge of the RB4/TCLK12 pin 0 = TMR2 increments off the internal clock TMR1CS: Timer1 Clock Source Select bit 1 = TMR1 increments off the falling edge of the RB4/TCLK12 pin 0 = TMR1 increments off the internal clock Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown R/W-0 CA2ED0 R/W-0 CA1ED1 R/W-0 CA1ED0 R/W-0 T16 R/W-0 TMR3CS R/W-0 TMR2CS R/W-0 TMR1CS bit 0
bit 5-4
bit 3
bit 2
bit 1
bit 0
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DS30289B-page 101
PIC17C7XX
REGISTER 13-2: TCON2 REGISTER (ADDRESS: 17h, BANK 3)
R-0 CA2OVF bit 7 bit 7 R-0 CA1OVF R/W-0 R/W-0 PWM2ON PWM1ON R/W-0 CA1/PR3 R/W-0 TMR3ON R/W-0 R/W-0 TMR2ON TMR1ON bit 0
CA2OVF: Capture2 Overflow Status bit This bit indicates that the capture value had not been read from the capture register pair (CA2H:CA2L) before the next capture event occurred. The capture register retains the oldest unread capture value (last capture before overflow). Subsequent capture events will not update the capture register with the TMR3 value until the capture register has been read (both bytes). 1 = Overflow occurred on Capture2 register 0 = No overflow occurred on Capture2 register CA1OVF: Capture1 Overflow Status bit This bit indicates that the capture value had not been read from the capture register pair (PR3H/ CA1H:PR3L/CA1L), before the next capture event occurred. The capture register retains the oldest unread capture value (last capture before overflow). Subsequent capture events will not update the capture register with the TMR3 value until the capture register has been read (both bytes). 1 = Overflow occurred on Capture1 register 0 = No overflow occurred on Capture1 register PWM2ON: PWM2 On bit 1 = PWM2 is enabled (The RB3/PWM2 pin ignores the state of the DDRB<3> bit.) 0 = PWM2 is disabled (The RB3/PWM2 pin uses the state of the DDRB<3> bit for data direction.) PWM1ON: PWM1 On bit 1 = PWM1 is enabled (The RB2/PWM1 pin ignores the state of the DDRB<2> bit.) 0 = PWM1 is disabled (The RB2/PWM1 pin uses the state of the DDRB<2> bit for data direction.) CA1/PR3: CA1/PR3 Register Mode Select bit 1 = Enables Capture1 (PR3H/CA1H:PR3L/CA1L is the Capture1 register. Timer3 runs without a period register.) 0 = Enables the Period register (PR3H/CA1H:PR3L/CA1L is the Period register for Timer3.) TMR3ON: Timer3 On bit 1 = Starts Timer3 0 = Stops Timer3 TMR2ON: Timer2 On bit This bit controls the incrementing of the TMR2 register. When TMR2:TMR1 form the 16-bit timer (T16 is set), TMR2ON must be set. This allows the MSB of the timer to increment. 1 = Starts Timer2 (must be enabled if the T16 bit (TCON1<3>) is set) 0 = Stops Timer2 TMR1ON: Timer1 On bit When T16 is set (in 16-bit Timer mode): 1 = Starts 16-bit TMR2:TMR1 0 = Stops 16-bit TMR2:TMR1 When T16 is clear (in 8-bit Timer mode: 1 = Starts 8-bit Timer1 0 = Stops 8-bit Timer1 Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
DS30289B-page 102
2000 Microchip Technology Inc.
PIC17C7XX
REGISTER 13-3: TCON3 REGISTER (ADDRESS: 16h, BANK 7)
U-0 -- bit 7 bit 7 bit 6 Unimplemented: Read as `0' CA4OVF: Capture4 Overflow Status bit This bit indicates that the capture value had not been read from the capture register pair (CA4H:CA4L) before the next capture event occurred. The capture register retains the oldest unread capture value (last capture before overflow). Subsequent capture events will not update the capture register with the TMR3 value until the capture register has been read (both bytes). 1 = Overflow occurred on Capture4 registers 0 = No overflow occurred on Capture4 registers CA3OVF: Capture3 Overflow Status bit This bit indicates that the capture value had not been read from the capture register pair (CA3H:CA3L) before the next capture event occurred. The capture register retains the oldest unread capture value (last capture before overflow). Subsequent capture events will not update the capture register with the TMR3 value until the capture register has been read (both bytes). 1 = Overflow occurred on Capture3 registers 0 = No overflow occurred on Capture3 registers CA4ED1:CA4ED0: Capture4 Mode Select bits 00 = Capture on every falling edge 01 = Capture on every rising edge 10 = Capture on every 4th rising edge 11 = Capture on every 16th rising edge CA3ED1:CA3ED0: Capture3 Mode Select bits 00 = Capture on every falling edge 01 = Capture on every rising edge 10 = Capture on every 4th rising edge 11 = Capture on every 16th rising edge PWM3ON: PWM3 On bit 1 = PWM3 is enabled (the RG5/PWM3 pin ignores the state of the DDRG<5> bit) 0 = PWM3 is disabled (the RG5/PWM3 pin uses the state of the DDRG<5> bit for data direction) Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown R-0 CA4OVF R-0 CA3OVF R/W-0 CA4ED1 R/W-0 CA4ED0 R/W-0 CA3ED1 R/W-0 R/W-0 CA3ED0 PWM3ON bit 0
bit 5
bit 4-3
bit 2-1
bit 0
2000 Microchip Technology Inc.
DS30289B-page 103
PIC17C7XX
13.1
13.1.1
Timer1 and Timer2
TIMER1, TIMER2 IN 8-BIT MODE
Both Timer1 and Timer2 will operate in 8-bit mode when the T16 bit is clear. These two timers can be independently configured to increment from the internal instruction cycle clock (TCY), or from an external clock source on the RB4/TCLK12 pin. The timer clock source is configured by the TMRxCS bit (x = 1 for Timer1, or = 2 for Timer2). When TMRxCS is clear, the clock source is internal and increments once every instruction cycle (FOSC/4). When TMRxCS is set, the clock source is the RB4/TCLK12 pin and the counters will increment on every falling edge of the RB4/TCLK12 pin. The timer increments from 00h until it equals the Period register (PRx). It then resets to 00h at the next increment cycle. The timer interrupt flag is set when the timer is reset. TMR1 and TMR2 have individual interrupt flag bits. The TMR1 interrupt flag bit is latched into TMR1IF and the TMR2 interrupt flag bit is latched into TMR2IF.
Each timer also has a corresponding interrupt enable bit (TMRxIE). The timer interrupt can be enabled/ disabled by setting/clearing this bit. For peripheral interrupts to be enabled, the Peripheral Interrupt Enable bit must be set (PEIE = '1') and global interrupt must be enabled (GLINTD = '0'). The timers can be turned on and off under software control. When the timer on control bit (TMRxON) is set, the timer increments from the clock source. When TMRxON is cleared, the timer is turned off and cannot cause the timer interrupt flag to be set.
13.1.1.1
External Clock Input for Timer1 and Timer2
When TMRxCS is set, the clock source is the RB4/ TCLK12 pin, and the counter will increment on every falling edge on the RB4/TCLK12 pin. The TCLK12 input is synchronized with internal phase clocks. This causes a delay from the time a falling edge appears on TCLK12 to the time TMR1 or TMR2 is actually incremented. For the external clock input timing requirements, see the Electrical Specification section.
FIGURE 13-1:
TIMER1 AND TIMER2 IN TWO 8-BIT TIMER/COUNTER MODE
0 1 TMR1ON (TCON2<0>) TMR1CS (TCON1<0>) TMR1 Comparator<8> Comparator x8 PR1 RESET Set TMR1IF (PIR1<4>) Equal
FOSC/4
RB4/TCLK12
1 FOSC/4 0 TMR2ON (TCON2<1>) TMR2CS (TCON1<1>) TMR2 Comparator<8> Comparator x8 PR2 RESET Set TMR2IF (PIR1<5>) Equal
DS30289B-page 104
2000 Microchip Technology Inc.
PIC17C7XX
13.1.2 TIMER1 AND TIMER2 IN 16-BIT MODE 13.1.2.1 External Clock Input for TMR2:TMR1
When TMR1CS is set, the 16-bit TMR2:TMR1 increments on the falling edge of clock input TCLK12. The input on the RB4/TCLK12 pin is sampled and synchronized by the internal phase clocks twice every instruction cycle. This causes a delay from the time a falling edge appears on RB4/TCLK12 to the time TMR2:TMR1 is actually incremented. For the external clock input timing requirements, see the Electrical Specification section.
To select 16-bit mode, set the T16 bit. In this mode, TMR2 and TMR1 are concatenated to form a 16-bit timer (TMR2:TMR1). The 16-bit timer increments until it matches the 16-bit period register (PR2:PR1). On the following timer clock, the timer value is reset to 0h, and the TMR1IF bit is set. When selecting the clock source for the 16-bit timer, the TMR1CS bit controls the entire 16-bit timer and TMR2CS is a "don't care", however, ensure that TMR2ON is set (allows TMR2 to increment). When TMR1CS is clear, the timer increments once every instruction cycle (FOSC/4). When TMR1CS is set, the timer increments on every falling edge of the RB4/ TCLK12 pin. For the 16-bit timer to increment, both TMR1ON and TMR2ON bits must be set (Table 13-2).
TABLE 13-2:
TURNING ON 16-BIT TIMER
Result 16-bit timer (TMR2:TMR1) ON Only TMR1 increments 16-bit timer OFF Timers in 8-bit mode
T16 TMR2ON TMR1ON 1 1 1 0 1 0 x 1 1 1 0 1
FIGURE 13-2:
TMR2 AND TMR1 IN 16-BIT TIMER/COUNTER MODE
1
RB4/TCLK12 FOSC/4
0 TMR1ON (TCON2<0>)
TMR1CS (TCON1<0>)
MSB RESET TMR2 x 8
LSB TMR1 x 8
Set Interrupt TMR1IF (PIR1<4>)
Equal
Comparator<8> Comparator x16 PR2 x 8 PR1 x 8
2000 Microchip Technology Inc.
DS30289B-page 105
PIC17C7XX
TABLE 13-3:
Address
SUMMARY OF TIMER1, TIMER2 AND TIMER3 REGISTERS
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR
0000 0000 0000 0000 -000 0000 xxxx xxxx xxxx xxxx
MCLR, WDT
16h, Bank 3 17h, Bank 3 16h, Bank 7 10h, Bank 2 11h, Bank 2 16h, Bank 1 17h, Bank 1
TCON1 TCON2 TCON3 TMR1 TMR2 PIR1 PIE1
CA2ED1
CA2ED0
CA1ED1
CA1ED0
T16
TMR3CS TMR2CS
TMR1CS TMR1ON PWM3ON
0000 0000 0000 0000 -000 0000 uuuu uuuu uuuu uuuu u000 0010 0000 0000 0000 0000 --11 qquu uuuu uuuu uuuu uuuu uu-- ---uu0- ---uu0- ---uuuu uuuu uuuu uuuu uuuu uuuu
CA2OVF CA1OVF PWM2ON PWM1ON CA1/PR3 TMR3ON TMR2ON -- CA4OVF CA3OVF CA4ED1 CA4ED0 CA3ED1 CA3ED0
Timer1's Register Timer2's Register RBIF RBIE PEIF -- TMR3IF TMR3IE T0CKIF -- TMR2IF TMR2IE T0IF STKAV TMR1IF TMR1IE INTF GLINTD CA2IF CA2IE PEIE TO CA1IF CA1IE T0CKIE PD TX1IF TX1IE T0IE POR RC1IF RC1IE INTE BOR
x000 0010 0000 0000 0000 0000 --11 11qq xxxx xxxx xxxx xxxx
07h, Unbanked INTSTA 06h, Unbanked CPUSTA 14h, Bank 2 15h, Bank 2 10h, Bank 3 11h, Bank 3 10h, Bank 7 12h, Bank 3 13h, Bank 3 11h, Bank 7 Legend: PR1 PR2 PW1DCL PW2DCL PW3DCL PW1DCH PW2DCH PW3DCH
Timer1 Period Register Timer2 Period Register DC1 DC1 DC1 DC9 DC9 DC9 DC0 DC0 DC0 DC8 DC8 DC8 -- TM2PW2 TM2PW3 DC7 DC7 DC7 -- -- -- DC6 DC6 DC6 -- -- -- DC5 DC5 DC5 -- -- -- DC4 DC4 DC4 -- -- -- DC3 DC3 DC3 -- -- -- DC2 DC2 DC2
xx-- ---xx0- ---xx0- ---xxxx xxxx xxxx xxxx xxxx xxxx
x = unknown, u = unchanged, - = unimplemented, read as a '0', q = value depends on condition. Shaded cells are not used by Timer1 or Timer2.
DS30289B-page 106
2000 Microchip Technology Inc.
PIC17C7XX
13.1.3 USING PULSE WIDTH MODULATION (PWM) OUTPUTS WITH TIMER1 AND TIMER2
The user needs to set the PWM1ON bit (TCON2<4>) to enable the PWM1 output. When the PWM1ON bit is set, the RB2/PWM1 pin is configured as PWM1 output and forced as an output, irrespective of the data direction bit (DDRB<2>). When the PWM1ON bit is clear, the pin behaves as a port pin and its direction is controlled by its data direction bit (DDRB<2>). Similarly, the PWM2ON (TCON2<5>) bit controls the configuration of the RB3/PWM2 pin and the PWM3ON (TCON3<0>) bit controls the configuration of the RG5/ PWM3 pin.
Three high speed pulse width modulation (PWM) outputs are provided. The PWM1 output uses Timer1 as its time base, while PWM2 and PWM3 may independently be software configured to use either Timer1 or Timer2 as the time base. The PWM outputs are on the RB2/PWM1, RB3/PWM2 and RG5/PWM3 pins. Each PWM output has a maximum resolution of 10bits. At 10-bit resolution, the PWM output frequency is 32.2 kHz (@ 32 MHz clock) and at 8-bit resolution the PWM output frequency is 128.9 kHz. The duty cycle of the output can vary from 0% to 100%. Figure 13-3 shows a simplified block diagram of a PWM module. The duty cycle registers are double buffered for glitch free operation. Figure 13-4 shows how a glitch could occur if the duty cycle registers were not double buffered.
FIGURE 13-3:
SIMPLIFIED PWM BLOCK DIAGRAM
PWxDCL<7:6> Write
Duty Cycle Registers PWxDCH
(Slave) Comparator TMRx Comparator PRy (Note 1)
Read PWMx R S Q PWMxON
Clear Timer, PWMx pin and Latch D.C.
Note 1: 8-bit timer is concatenated with 2-bit internal Q clock or 2 bits of the prescaler to create 10-bit time base.
FIGURE 13-4:
PWM OUTPUT (NOT BUFFERED)
0
10
20
30
40
0
10
20
30
40
0
PWM Output
Timer Interrupt
Write New PWM Duty Cycle Value
Timer Interrupt New PWM Duty Cycle Value Transferred to Slave
Note: The dotted line shows PWM output if duty cycle registers were not double buffered. If the new duty cycle is written after the timer has passed that value, then the PWM does not reset at all during the current cycle, causing a "glitch". In this example, PWM period = 50. Old duty cycle is 30. New duty cycle value is 10.
2000 Microchip Technology Inc.
DS30289B-page 107
PIC17C7XX
13.1.3.1 PWM Periods
The period of the PWM1 output is determined by Timer1 and its period register (PR1). The period of the PWM2 and PWM3 outputs can be individually software configured to use either Timer1 or Timer2 as the timebase. For PWM2, when TM2PW2 bit (PW2DCL<5>) is clear, the time base is determined by TMR1 and PR1 and when TM2PW2 is set, the time base is determined by Timer2 and PR2. For PWM3, when TM2PW3 bit (PW3DCL<5>) is clear, the time base is determined by TMR1 and PR1, and when TM2PW3 is set, the time base is determined by Timer2 and PR2. Running two different PWM outputs on two different timers allows different PWM periods. Running all PWMs from Timer1 allows the best use of resources by freeing Timer2 to operate as an 8-bit timer. Timer1 and Timer2 cannot be used as a 16-bit timer if any PWM is being used. The PWM periods can be calculated as follows: period of PWM1 = [(PR1) + 1] x 4TOSC period of PWM2 = [(PR1) + 1] x 4TOSC or [(PR2) + 1] x 4TOSC period of PWM3 = [(PR1) + 1] x 4TOSC or [(PR2) + 1] x 4TOSC The duty cycle of PWMx is determined by the 10-bit value DCx<9:0>. The upper 8-bits are from register PWxDCH and the lower 2-bits are from PWxDCL<7:6> (PWxDCH:PWxDCL<7:6>). Table 13-4 shows the maximum PWM frequency (FPWM), given the value in the period register. The number of bits of resolution that the PWM can achieve depends on the operation frequency of the device as well as the PWM frequency (FPWM). Maximum PWM resolution (bits) for a given PWM frequency: log FOSC ( FPWM ) bits log (2) where: FPWM = 1 / period of PWM The PWMx duty cycle is as follows: PWMx Duty Cycle = (DCx) x TOSC where DCx represents PWxDCH:PWxDCL. the 10-bit value from If DCx = 0, then the duty cycle is zero. If PRx = PWxDCH, then the PWM output will be low for one to four Q-clocks (depending on the state of the PWxDCL<7:6> bits). For a duty cycle to be 100%, the PWxDCH value must be greater then the PRx value. The duty cycle registers for both PWM outputs are double buffered. When the user writes to these registers, they are stored in master latches. When TMR1 (or TMR2) overflows and a new PWM period begins, the master latch values are transferred to the slave latches and the PWMx pin is forced high. Note: For PW1DCH, PW1DCL, PW2DCH, PW2DCL, PW3DCH and PW3DCL registers, a write operation writes to the "master latches", while a read operation reads the "slave latches". As a result, the user may not read back what was just written to the duty cycle registers (until transferred to slave latch).
The user should also avoid any "read-modify-write" operations on the duty cycle registers, such as: ADDWF PW1DCH. This may cause duty cycle outputs that are unpredictable.
TABLE 13-4:
PWM FREQUENCY vs. RESOLUTION AT 33 MHz
Frequency (kHz) 32.2 64.5 90.66 128.9 0x3F 8-bit 6-bit 515.6 0x0F 6-bit 4-bit
PWM Frequency PRx Value High Resolution Standard Resolution 13.1.3.2
0xFF 0x7F 0x5A 10-bit 9-bit 8.5-bit 8-bit 7-bit 6.5-bit
PWM INTERRUPTS
=
The PWM modules make use of the TMR1 and/or TMR2 interrupts. A timer interrupt is generated when TMR1 or TMR2 equals its period register and on the following increment is cleared to zero. This interrupt also marks the beginning of a PWM cycle. The user can write new duty cycle values before the timer rollover. The TMR1 interrupt is latched into the TMR1IF bit and the TMR2 interrupt is latched into the TMR2IF bit. These flags must be cleared in software.
DS30289B-page 108
2000 Microchip Technology Inc.
PIC17C7XX
13.1.3.3 External Clock Source 13.1.3.4
The PWMs will operate, regardless of the clock source of the timer. The use of an external clock has ramifications that must be understood. Because the external TCLK12 input is synchronized internally (sampled once per instruction cycle), the time TCLK12 changes to the time the timer increments, will vary by as much as 1TCY (one instruction cycle). This will cause jitter in the duty cycle as well as the period of the PWM output. This jitter will be 1TCY, unless the external clock is synchronized with the processor clock. Use of one of the PWM outputs as the clock source to the TCLK12 input, will supply a synchronized clock. In general, when using an external clock source for PWM, its frequency should be much less than the device frequency (FOSC).
Maximum Resolution/Frequency for External Clock Input
The use of an external clock for the PWM time base (Timer1 or Timer2) limits the PWM output to a maximum resolution of 8-bits. The PWxDCL<7:6> bits must be kept cleared. Use of any other value will distort the PWM output. All resolutions are supported when internal clock mode is selected. The maximum attainable frequency is also lower. This is a result of the timing requirements of an external clock input for a timer (see the Electrical Specification section). The maximum PWM frequency, when the timers clock source is the RB4/TCLK12 pin, is shown in Table 13-4 (Standard Resolution mode).
TABLE 13-5:
Address
REGISTERS/BITS ASSOCIATED WITH PWM
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR MCLR, WDT
16h, Bank 3 17h, Bank 3 16h, Bank 7 10h, Bank 2 11h, Bank 2 16h, Bank 1 17h, Bank 1
TCON1 TCON2 TCON3 TMR1 TMR2 PIR1 PIE1
CA2ED1 CA2OVF --
CA2ED0 CA1OVF CA4OVF
CA1ED1 PWM2ON CA3OVF
CA1ED0 PWM1ON CA4ED1
T16
TMR3CS
TMR2CS TMR2ON CA3ED0
TMR1CS TMR1ON PWM3ON
0000 0000 0000 0000 0000 0000 0000 0000 -000 0000 -000 0000 xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
CA1/PR3 TMR3ON CA4ED0 CA3ED1
Timer1's Register Timer2's Register RBIF RBIE PEIF -- TMR3IF TMR3IE T0CKIF -- TMR2IF TMR2IE T0IF STKAV TMR1IF TMR1IE INTF GLINTD CA2IF CA2IE PEIE TO CA1IF CA1IE T0CKIE PD TX1IF TX1IE T0IE POR RC1IF RC1IE INTE BOR
x000 0010 u000 0010 0000 0000 0000 0000 0000 0000 0000 0000 --11 11qq --11 qquu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
07h, Unbanked INTSTA 06h, Unbanked CPUSTA 14h, Bank 2 15h, Bank 2 10h, Bank 3 11h, Bank 3 10h, Bank 7 12h, Bank 3 13h, Bank 3 11h, Bank 7 Legend: PR1 PR2 PW1DCL PW2DCL PW3DCL PW1DCH PW2DCH PW3DCH
Timer1 Period Register Timer2 Period Register DC1 DC1 DC1 DC9 DC9 DC9 DC0 DC0 DC0 DC8 DC8 DC8 -- TM2PW2 TM2PW3 DC7 DC7 DC7 -- -- -- DC6 DC6 DC6 -- -- -- DC5 DC5 DC5 -- -- -- DC4 DC4 DC4 -- -- -- DC3 DC3 DC3 -- -- -- DC2 DC2 DC2
xx-- ---- uu-- ---xx0- ---- uu0- ---xx0- ---- uu0- ---xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu
x = unknown, u = unchanged, - = unimplemented, read as '0', q = value depends on conditions. Shaded cells are not used by PWM Module.
2000 Microchip Technology Inc.
DS30289B-page 109
PIC17C7XX
13.2 Timer3
Timer3 is a 16-bit timer consisting of the TMR3H and TMR3L registers. TMR3H is the high byte of the timer and TMR3L is the low byte. This timer has an associated 16-bit period register (PR3H/CA1H:PR3L/CA1L). This period register can be software configured to be a another 16-bit capture register. When the TMR3CS bit (TCON1<2>) is clear, the timer increments every instruction cycle (FOSC/4). When TMR3CS is set, the counter increments on every falling edge of the RB5/TCLK3 pin. In either mode, the TMR3ON bit must be set for the timer/counter to increment. When TMR3ON is clear, the timer will not increment or set flag bit TMR3IF. Timer3 has two modes of operation, depending on the CA1/PR3 bit (TCON2<3>). These modes are: * Three capture and one period register mode * Four capture register mode The PIC17C7XX has up to four 16-bit capture registers that capture the 16-bit value of TMR3 when events are detected on capture pins. There are four capture pins (RB0/CAP1, RB1/CAP2, RG4/CAP3, and RE3/CAP4), one for each capture register pair. The capture pins are multiplexed with the I/O pins. An event can be: * * * * A rising edge A falling edge Every 4th rising edge Every 16th rising edge
Each 16-bit capture register has an interrupt flag associated with it. The flag is set when a capture is made. The capture modules are truly part of the Timer3 block. Figure 13-5 and Figure 13-6 show the block diagrams for the two modes of operation.
13.2.1
THREE CAPTURE AND ONE PERIOD REGISTER MODE
In this mode, registers PR3H/CA1H and PR3L/CA1L constitute a 16-bit period register. A block diagram is shown in Figure 13-5. The timer increments until it equals the period register and then resets to 0000h on the next timer clock. TMR3 Interrupt Flag bit (TMR3IF) is set at this point. This interrupt can be disabled by clearing the TMR3 Interrupt Enable bit (TMR3IE). TMR3IF must be cleared in software.
FIGURE 13-5:
TIMER3 WITH THREE CAPTURE AND ONE PERIOD REGISTER BLOCK DIAGRAM
TMR3CS (TCON1<2>) FOSC/4 0 1 TMR3H TMR3ON (TCON2<2>) Capture2 Enable TMR3L PR3H/CA1H PR3L/CA1L Set TMR3IF (PIR1<6>) Equal Reset
Comparator x16 Comparator<8>
RB5/TCLK3
Edge select, Prescaler select RB1/CAP2 2 CA2ED1: CA2ED0 (TCON1<7:6>) Edge select, Prescaler select RG4/CAP3 2 CA3ED1: CA3ED0 (TCON3<2:1>)
CA2H Set CA2IF (PIR1<3>) Capture3 Enable
CA2L
CA3H Set CA3IF (PIR2<2>)
CA3L
Edge select, Prescaler select RE3/CAP4 2 CA4ED1: CA4ED0 (TCON3<4:3>)
Capture4 Enable
CA4H Set CA4IF (PIR2<3>)
CA4L
DS30289B-page 110
2000 Microchip Technology Inc.
PIC17C7XX
This mode (3 Capture, 1 Period) is selected if control bit CA1/PR3 is clear. In this mode, the Capture1 register, consisting of high byte (PR3H/CA1H) and low byte (PR3L/CA1L), is configured as the period control register for TMR3. Capture1 is disabled in this mode and the corresponding interrupt bit, CA1IF, is never set. TMR3 increments until it equals the value in the period register and then resets to 0000h on the next timer clock. All other Captures are active in this mode. The input on the capture pin CAPx is synchronized internally to internal phase clocks. This imposes certain restrictions on the input waveform (see the Electrical Specification section for timing). The capture overflow status flag bit is double buffered. The master bit is set if one captured word is already residing in the Capture register (CAxH:CAxL) and another "event" has occurred on the CAPx pin. The new event will not transfer the TMR3 value to the capture register, protecting the previous unread capture value. When the user reads both the high and the low bytes (in any order) of the Capture register, the master overflow bit is transferred to the slave overflow bit (CAxOVF) and then the master bit is reset. The user can then read TCONx to determine the value of CAxOVF. The recommended sequence to read capture registers and capture overflow flag bits is shown in Example 13-1.
13.2.1.1
Capture Operation
The CAxED1 and CAxED0 bits determine the event on which capture will occur. The possible events are: * * * * Capture on every falling edge Capture on every rising edge Capture every 4th rising edge Capture every 16th rising edge
When a capture takes place, an interrupt flag is latched into the CAxIF bit. This interrupt can be enabled by setting the corresponding mask bit CAxIE. The Peripheral Interrupt Enable bit (PEIE) must be set and the Global Interrupt Disable bit (GLINTD) must be cleared for the interrupt to be acknowledged. The CAxIF interrupt flag bit is cleared in software. When the capture prescale select is changed, the prescaler is not reset and an event may be generated. Therefore, the first capture after such a change will be ambiguous. However, it sets the time-base for the next capture. The prescaler is reset upon chip RESET. The capture pin, CAPx, is a multiplexed pin. When used as a port pin, the capture is not disabled. However, the user can simply disable the Capture interrupt by clearing CAxIE. If the CAPx pin is used as an output pin, the user can activate a capture by writing to the port pin. This may be useful during development phase to emulate a capture interrupt.
2000 Microchip Technology Inc.
DS30289B-page 111
PIC17C7XX
13.2.2 FOUR CAPTURE MODE
This mode is selected by setting bit CA1/PR3. A block diagram is shown in Figure 13-6. In this mode, TMR3 runs without a period register and increments from 0000h to FFFFh and rolls over to 0000h. The TMR3 interrupt Flag (TMR3IF) is set on this rollover. The TMR3IF bit must be cleared in software. Registers PR3H/CA1H and PR3L/CA1L make a 16-bit capture register (Capture1). It captures events on pin RB0/CAP1. Capture mode is configured by the CA1ED1 and CA1ED0 bits. Capture1 Interrupt Flag bit (CA1IF) is set upon detection of the capture event. The corresponding interrupt mask bit is CA1IE. The Capture1 Overflow Status bit is CA1OVF. All the captures operate in the same manner. Refer to Section 13.2.1 for the operation of capture.
FIGURE 13-6:
FOSC/4
TIMER3 WITH FOUR CAPTURES BLOCK DIAGRAM
0 1 TMR3H TMR3ON (TCON2<2>) TMR3L Set TMR3IF (PIR1<6>)
RB5/TCLK3
TMR3CS (TCON1<2>)
Edge Select, Prescaler Select RB0/CAP1 2 CA1ED1, CA1ED0 (TCON1<5:4>) Edge Select, Prescaler Select RB1/CAP2 2 CA2ED1, CA2ED0 (TCON1<7:6>) Edge Select, Prescaler Select RG4/CAP3 2 CA3ED1: CA3ED0 (TCON3<2:1>)
Capture1 Enable Set CA1IF (PIR1<2>) PR3H/CA1H PR3L/CA1L
Capture2 Enable Set CA2IF (PIR1<3>) CA2H CA2L
Capture3 Enable Set CA3IF (PIR2<2>) CA3H CA3L
Edge Select, Prescaler Select RE3/CAP4 2 CA4ED1: CA4ED0 (TCON3<4:3>)
Capture4 Enable Set CA4IF (PIR2<3>) CA4H CA4L
DS30289B-page 112
2000 Microchip Technology Inc.
PIC17C7XX
13.2.3 READING THE CAPTURE REGISTERS
order) of the Capture register, the master overflow bit is transferred to the slave overflow bit (CAxOVF) and then the master bit is reset. The user can then read TCONx to determine the value of CAxOVF. An example of an instruction sequence to read capture registers and capture overflow flag bits is shown in Example 13-1. Depending on the capture source, different registers will need to be read.
The Capture overflow status flag bits are double buffered. The master bit is set if one captured word is already residing in the Capture register and another "event" has occurred on the CAPx pin. The new event will not transfer the TMR3 value to the capture register, protecting the previous unread capture value. When the user reads both the high and the low bytes (in any
EXAMPLE 13-1:
MOVLB MOVPF MOVPF MOVPF
SEQUENCE TO READ CAPTURE REGISTERS
; ; ; ; Select Bank 3 Read Capture2 low byte, store in LO_BYTE Read Capture2 high byte, store in HI_BYTE Read TCON2 into file STAT_VAL
3 CA2L, LO_BYTE CA2H, HI_BYTE TCON2, STAT_VAL
TABLE 13-6:
Address
REGISTERS ASSOCIATED WITH CAPTURE
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR
0000 0000
MCLR, WDT
16h, Bank 3 17h, Bank 3 16h, Bank 7 12h, Bank 2 13h, Bank 2 16h, Bank 1 17h, Bank 1 10h, Bank 4 11h, Bank 4
TCON1 TCON2 TCON3 TMR3L TMR3H PIR1 PIE1 PIR2 PIE2
CA2ED1 CA2ED0 CA2OVF CA1OVF -- CA4OVF
CA1ED1 PWM2ON CA3OVF
CA1ED0
T16
TMR3CS TMR2CS TMR1CS
0000 0000 0000 0000 -000 0000 uuuu uuuu uuuu uuuu u000 0010 0000 0000 000- 0010 000- 0000 0000 0000 --11 qquu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu uuuu
PWM1ON CA1/PR3 TMR3ON TMR2ON TMR1ON 0000 0000 CA4ED1 CA4ED0 CA3ED1 CA3ED0 PWM3ON -000 0000
xxxx xxxx xxxx xxxx
Holding Register for the Low Byte of the 16-bit TMR3 Register Holding Register for the High Byte of the 16-bit TMR3 Register RBIF RBIE SSPIF SSPIE PEIF -- TMR3IF TMR3IE BCLIF BCLIE T0CKIF -- TMR2IF TMR2IE ADIF ADIE T0IF STKAV TMR1IF TMR1IE -- -- INTF GLINTD CA2IF CA2IE CA4IF CA4IE PEIE TO CA1IF CA1IE CA3IF CA3IE T0CKIE PD TX1IF TX1IE TX2IF TX2IE T0IE POR RC1IF RC1IE RC2IF RC2IE INTE BOR
x000 0010 0000 0000 000- 0010 000- 0000 0000 0000 --11 11qq xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx
07h, Unbanked INTSTA 06h, Unbanked CPUSTA 16h, Bank 2 17h, Bank 2 14h, Bank 3 15h, Bank 3 12h, Bank 7 13h, Bank 7 14h, Bank 7 15h, Bank 7 Legend: PR3L/CA1L
Timer3 Period Register, Low Byte/Capture1 Register, Low Byte
PR3H/CA1H Timer3 Period Register, High Byte/Capture1 Register, High Byte CA2L CA2H CA3L CA3H CA4L CA4H Capture2 Low Byte Capture2 High Byte Capture3 Low Byte Capture3 High Byte Capture4 Low Byte Capture4 High Byte
x = unknown, u = unchanged, - = unimplemented, read as '0', q = value depends on condition. Shaded cells are not used by Capture.
2000 Microchip Technology Inc.
DS30289B-page 113
PIC17C7XX
13.2.4 EXTERNAL CLOCK INPUT FOR TIMER3 13.2.5 READING/WRITING TIMER3
Since Timer3 is a 16-bit timer and only 8-bits at a time can be read or written, care should be taken when reading or writing while the timer is running. The best method is to stop the timer, perform any read or write operation and then restart Timer3 (using the TMR3ON bit). However, if it is necessary to keep Timer3 freerunning, care must be taken. For writing to the 16-bit TMR3, Example 13-2 may be used. For reading the 16bit TMR3, Example 13-3 may be used. Interrupts must be disabled during this routine.
When TMR3CS is set, the 16-bit TMR3 increments on the falling edge of clock input TCLK3. The input on the RB5/TCLK3 pin is sampled and synchronized by the internal phase clocks, twice every instruction cycle. This causes a delay from the time a falling edge appears on TCLK3 to the time TMR3 is actually incremented. For the external clock input timing requirements, see the Electrical Specification section. Figure 13-7 shows the timing diagram when operating from an external clock.
EXAMPLE 13-2:
BSF MOVFP MOVFP BCF
WRITING TO TMR3
GLINTD TMR3L TMR3H GLINTD ; Disable interrupts ; ; ; Done, enable interrupts
CPUSTA, RAM_L, RAM_H, CPUSTA,
EXAMPLE 13-3:
MOVPF MOVPF MOVFP CPFSLT RETURN MOVPF MOVPF RETURN
READING FROM TMR3
; ; ; ; ; ; ; ; read low TMR3 read high TMR3 tmplo -> wreg TMR3L < wreg? no then return read low TMR3 read high TMR3 return
TMR3L, TMPLO TMR3H, TMPHI TMPLO, WREG TMR3L TMR3L, TMPLO TMR3H, TMPHI
FIGURE 13-7:
TIMER1, TIMER2 AND TIMER3 OPERATION (IN COUNTER MODE)
Q1Q2Q3Q4 Q1Q2Q3Q4 Q1Q2Q3Q4 Q1Q2Q3Q4 Q1Q2Q3Q4Q1Q2Q3Q4
TCLK12 or TCLK3 TMR1, TMR2, or TMR3 PR1, PR2, or PR3H:PR3L WR_TMR RD_TMR TMRxIF Instruction Executed
MOVWF TMRx Write to TMRx MOVFP TMRx,W Read TMRx MOVFP TMRx,W Read TMRx
34h
35h
A8h
A9h
00h
'A9h'
'A9h'
Note 1: TCLK12 is sampled in Q2 and Q4. 2: indicates a sampling point. 3: The latency from TCLK12 to timer increment is between 2Tosc and 6Tosc.
DS30289B-page 114
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 13-8: TIMER1, TIMER2 AND TIMER3 OPERATION (IN TIMER MODE)
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4
AD15:AD0
ALE Instruction Fetched MOVF MOVWF MOVF TMR1, W TMR1 TMR1, W Write TMR1 Read TMR1 Read TMR1 MOVLB 3 BSF TCON2, 0 Stop TMR1 NOP BCF TCON2, 0 Start TMR1 NOP NOP NOP NOP
TMR1 PR1
04h
05h
03h
04h
05h
06h
07h
08h
00h
TMR1ON
WR_TMR1
WR_TCON2
TMR1IF
RD_TMR1 TMR1 Reads 03h TMR1 Reads 04h
2000 Microchip Technology Inc.
DS30289B-page 115
PIC17C7XX
NOTES:
DS30289B-page 116
2000 Microchip Technology Inc.
PIC17C7XX
14.0 UNIVERSAL SYNCHRONOUS ASYNCHRONOUS RECEIVER TRANSMITTER (USART) MODULES
TABLE 14-1:
Generic Name RCSTA TXSTA SPBRG RCREG TXREG RCIE RCIF TXIE TXIF RX/DT TX/CK
USART MODULE GENERIC NAMES
USART1 Name USART2 Name
Each USART module is a serial I/O module. There are two USART modules that are available on the PIC17C7XX. They are specified as USART1 and USART2. The description of the operation of these modules is generic in regard to the register names and pin names used. Table 14-1 shows the generic names that are used in the description of operation and the actual names for both USART1 and USART2. Since the control bits in each register have the same function, their names are the same (there is no need to differentiate). The Transmit Status and Control Register (TXSTA) is shown in Figure 14-1, while the Receive Status and Control Register (RCSTA) is shown in Figure 14-2.
Registers RCSTA1 RCSTA2 TXSTA1 TXSTA2 SPBRG1 SPBRG2 RCREG1 RCREG2 TXREG1 TXREG2 Interrupt Control Bits RC1IE RC2IE RC1IF RC2IF TX1IE TX2IE TX1IF TX2IF Pins RA4/RX1/DT1 RG6/RX2/DT2 RA5/TX1/CK1 RG7/TX2/CK2
REGISTER 14-1:
TXSTA1 REGISTER (ADDRESS: 15h, BANK 0) TXSTA2 REGISTER (ADDRESS: 15h, BANK 4)
R/W-0 CSRC bit 7 R/W-0 TX9 R/W-0 TXEN R/W-0 SYNC U-0 -- U-0 -- R-1 TRMT R/W-x TX9D bit 0
bit 7
CSRC: Clock Source Select bit Synchronous mode: 1 = Master mode (clock generated internally from BRG) 0 = Slave mode (clock from external source) Asynchronous mode: Don't care
bit 6
TX9: 9-bit Transmit Select bit 1 = Selects 9-bit transmission 0 = Selects 8-bit transmission TXEN: Transmit Enable bit 1 = Transmit enabled 0 = Transmit disabled SREN/CREN overrides TXEN in SYNC mode SYNC: USART Mode Select bit (Synchronous/Asynchronous) 1 = Synchronous mode 0 = Asynchronous mode Unimplemented: Read as '0' TRMT: Transmit Shift Register (TSR) Empty bit 1 = TSR empty 0 = TSR full TX9D: 9th bit of Transmit Data (can be used to calculate the parity in software) Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 5
bit 4
bit 3-2 bit 1
bit 0
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PIC17C7XX
The USART can be configured as a full duplex asynchronous system that can communicate with peripheral devices such as CRT terminals and personal computers, or it can be configured as a half duplex synchronous system that can communicate with peripheral devices such as A/D or D/A integrated circuits, Serial EEPROMs etc. The USART can be configured in the following modes: * Asynchronous (full duplex) * Synchronous - Master (half duplex) * Synchronous - Slave (half duplex) The SPEN (RCSTA<7>) bit has to be set in order to configure the I/O pins as the Serial Communication Interface (USART). The USART module will control the direction of the RX/ DT and TX/CK pins, depending on the states of the USART configuration bits in the RCSTA and TXSTA registers. The bits that control I/O direction are: * * * * * SPEN TXEN SREN CREN CSRC
REGISTER 14-2: RCSTA1 REGISTER (ADDRESS: 13h, BANK 0) RCSTA2 REGISTER (ADDRESS: 13h, BANK 4)
R/W-0 SPEN bit 7 bit 7 SPEN: Serial Port Enable bit 1 = Configures TX/CK and RX/DT pins as serial port pins 0 = Serial port disabled RX9: 9-bit Receive Select bit 1 = Selects 9-bit reception 0 = Selects 8-bit reception SREN: Single Receive Enable bit This bit enables the reception of a single byte. After receiving the byte, this bit is automatically cleared. Synchronous mode: 1 = Enable reception 0 = Disable reception Note: This bit is ignored in synchronous slave reception. Asynchronous mode: Don't care bit 4 CREN: Continuous Receive Enable bit This bit enables the continuous reception of serial data. Asynchronous mode: 1 = Enable continuous reception 0 = Disables continuous reception Synchronous mode: 1 = Enables continuous reception until CREN is cleared (CREN overrides SREN) 0 = Disables continuous reception bit 3 bit 2 Unimplemented: Read as '0' FERR: Framing Error bit 1 = Framing error (updated by reading RCREG) 0 = No framing error bit OERR: Overrun Error bit 1 = Overrun (cleared by clearing CREN) 0 = No overrun error RX9D: 9th bit of Receive Data (can be the software calculated parity bit) Legend: R = Readable bit - n = Value at POR Reset
DS30289B-page 118
R/W-0 RX9
R/W-0 SREN
R/W-0 CREN
U-0 --
R-0 FERR
R-0 OERR
R-x RX9D bit 0
bit 6
bit 5
bit 1
bit 0
W = Writable bit '1' = Bit is set
U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 14-1: USART TRANSMIT
Sync Master/Slave
BRG Sync/Async Sync/Async CK/TX Start 0 1 * * * 7 8 Stop Clock TSR
/4 Sync/Async / 16
Load DT TXREG 0 1 *** 7 8 Bit Count TXEN/ Write to TXREG Interrupt TXSTA<0> TXIE
Data Bus
FIGURE 14-2:
USART RECEIVE
/4 Master/Slave Sync Sync/Async Async/Sync Interrupt
OSC
BRG
RCIE
CK
Buffer Logic SPEN Buffer Logic
Enable Bit Count / 16 START Detect Clock Data RSR MSb LSb Stop 8 7 * * * 1 0 FIFO Logic RCREG FERR FERR RX9D RX9D 7 *** 1 0 7 *** 1 0 Data Bus Clk FIFO SREN/ CREN/ Start_Bit
RX
Majority Detect
RX9 Async/Sync
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14.1 USART Baud Rate Generator (BRG)
EXAMPLE 14-1: CALCULATING BAUD RATE ERROR
Desired Baud Rate = FOSC / (64 (X + 1)) 9600 = 16000000 /(64 (X + 1)) X = 25.042 25 = 9615 Error = (Calculated Baud Rate - Desired Baud Rate) Desired Baud Rate = (9615 - 9600) / 9600 = 0.16% Calculated Baud Rate = 16000000 / (64 (25 + 1))
The BRG supports both the Asynchronous and Synchronous modes of the USART. It is a dedicated 8-bit baud rate generator. The SPBRG register controls the period of a free running 8-bit timer. Table 14-2 shows the formula for computation of the baud rate for different USART modes. These only apply when the USART is in Synchronous Master mode (internal clock) and Asynchronous mode. Given the desired baud rate and Fosc, the nearest integer value between 0 and 255 can be calculated using the formula below. The error in baud rate can then be determined.
TABLE 14-2:
SYNC
BAUD RATE FORMULA
Mode Baud Rate
Writing a new value to the SPBRG, 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. Effects of Reset After any device RESET, the SPBRG register is cleared. The SPBRG register will need to be loaded with the desired value after each RESET.
0 Asynchronous FOSC/(64(X+1)) FOSC/(4(X+1)) 1 Synchronous X = value in SPBRG (0 to 255) Example 14-1 shows the calculation of the baud rate error for the following conditions: FOSC = 16 MHz Desired Baud Rate = 9600 SYNC = 0
TABLE 14-3:
Address
REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR
0000 -00x 0000 --1x 0000 0000
MCLR, WDT
USART1
13h, Bank 0 15h, Bank 0 17h, Bank 0 13h, Bank 4 15h, Bank 4 17h, Bank 4
RCSTA1 TXSTA1 SPBRG1 RCSTA2 TXSTA2 SPBRG2
SPEN CSRC
RX9 TX9
SREN TXEN
CREN SYNC
-- --
FERR --
OERR TRMT
RX9D TX9D
0000 -00u 0000 --1u 0000 0000 0000 -00u 0000 --1u 0000 0000
Baud Rate Generator Register SPEN CSRC RX9 TX9 SREN TXEN CREN SYNC -- -- FERR -- OERR TRMT RX9D TX9D
USART2
0000 -00x 0000 --1x 0000 0000
Baud Rate Generator Register
Legend:
x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the Baud Rate Generator.
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PIC17C7XX
TABLE 14-4:
BAUD RATE (K) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW BAUD RATE (K) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW BAUD RATE (K) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW
BAUD RATES FOR SYNCHRONOUS MODE
FOSC = 25 MHz FOSC = 20 MHz FOSC = 16 MHz SPBRG SPBRG SPBRG SPBRG VALUE VALUE VALUE VALUE %ERROR (DECIMAL) KBAUD %ERROR (DECIMAL) KBAUD %ERROR (DECIMAL) KBAUD %ERROR (DECIMAL)
-- -- -- -- -- +0.39 -0.07 -1.79 -2.94 -- -- -- -- -- -- -- 106 85 27 16 0 255 NA NA NA NA NA 77.16 96.15 297.62 480.77 6250 24.41 SPBRG VALUE (DECIMAL) -- -- -- 255 129 32 25 7 4 0 255 SPBRG VALUE (DECIMAL) -- -- -- 92 46 11 8 2 -- 0 255 -- -- -- -- -- +0.47 +0.16 -0.79 -3.85 -- -- -- -- -- -- -- 80 64 20 12 0 255 NA NA NA NA 19.53 76.92 96.15 294.1 500 5000 19.53 -- -- -- -- +1.73 +0.16 +0.16 -1.96 0 -- -- SPBRG VALUE (DECIMAL) -- -- -- 185 92 22 18 5 -- 0 255 SPBRG VALUE (DECIMAL) -- 207 103 25 12 2 -- -- -- 0 255 -- -- -- -- 255 64 51 16 9 0 255 NA NA NA NA 19.23 76.92 95.24 307.69 500 4000 15.625 -- -- -- -- +0.16 +0.16 -0.79 +2.56 0 -- -- -- -- -- -- 207 51 41 12 7 0 255 SPBRG VALUE (DECIMAL) -- -- -- 131 65 15 12 3 -- 0 255 SPBRG VALUE (DECIMAL) 26 6 -- -- -- -- -- -- -- 0 255
FOSC = 33 MHz
KBAUD NA NA NA NA NA 77.10 95.93 294.64 485.29 8250 32.22
FOSC = 10 MHz
KBAUD NA NA NA 9.766 19.23 75.76 96.15 312.5 500 2500 9.766 FOSC = 3.579 MHz KBAUD NA NA NA 9.622 19.04 74.57 99.43 298.3 NA 894.9 3.496 %ERROR -- -- -- +0.23 -0.83 -2.90 _3.57 -0.57 -- -- -- %ERROR -- -- -- +1.73 +0.16 -1.36 +0.16 +4.17 0 -- --
FOSC = 7.159 MHz
KBAUD NA NA NA 9.622 19.24 77.82 94.20 298.3 NA 1789.8 6.991 %ERROR -- -- -- +0.23 +0.23 +1.32 -1.88 -0.57 -- -- --
FOSC = 5.068 MHz
KBAUD NA NA NA 9.6 19.2 79.2 97.48 316.8 NA 1267 4.950 %ERROR -- -- -- 0 0 +3.13 +1.54 +5.60 -- -- --
FOSC = 1 MHz
KBAUD NA 1.202 2.404 9.615 19.24 83.34 NA NA NA 250 0.976 %ERROR -- +0.16 +0.16 +0.16 +0.16 +8.51 -- -- -- -- --
FOSC = 32.768 kHz
KBAUD 0.303 1.170 NA NA NA NA NA NA NA 8.192 0.032 %ERROR +1.14 -2.48 -- -- -- -- -- -- -- -- --
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TABLE 14-5:
BAUD RATE (K) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW BAUD RATE (K) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW BAUD RATE (K) 0.3 1.2 2.4 9.6 19.2 76.8 96 300 500 HIGH LOW
BAUD RATES FOR ASYNCHRONOUS MODE
FOSC = 25 MHz FOSC = 20 MHz FOSC = 16 MHz SPBRG SPBRG SPBRG SPBRG VALUE VALUE VALUE VALUE %ERROR (DECIMAL) KBAUD %ERROR (DECIMAL) KBAUD %ERROR (DECIMAL) KBAUD %ERROR (DECIMAL)
-- -- -0.07 -0.54 -0.54 -4.09 +7.42 -14.06 +3.13 -- -- -- -- 214 53 26 6 4 1 0 0 255 NA NA 2.396 9.53 19.53 78.13 97.65 390.63 NA -- 1.53 SPBRG VALUE (DECIMAL) -- 129 64 15 7 1 -- -- -- 0 255 SPBRG VALUE (DECIMAL) 185 46 22 5 2 -- -- -- -- 0 255 -- -- 0.14 -0.76 +1.73 +1.73 +1.73 +30.21 -- -- -- -- -- 162 40 19 4 3 0 -- 0 255 NA 1.221 2.404 9.469 19.53 78.13 104.2 312.5 NA 312.5 1.221 -- +1.73 +0.16 -1.36 +1.73 +1.73 +8.51 +4.17 -- -- -- SPBRG VALUE (DECIMAL) -- 92 46 11 5 -- -- -- -- 0 255 SPBRG VALUE (DECIMAL) 51 12 6 -- -- -- -- -- -- 0 255 -- 255 129 32 15 3 2 0 -- 0 255 NA 1.202 2.404 9.615 19.23 83.33 NA NA NA 250 0.977 -- +0.16 +0.16 +0.16 +0.16 +8.51 -- -- -- -- -- -- 207 103 25 12 2 -- -- -- 0 255 SPBRG VALUE (DECIMAL) 255 65 32 7 3 0 -- -- -- 0 255 SPBRG VALUE (DECIMAL) 1 -- -- -- -- -- -- -- -- 0 255
FOSC = 33 MHz
KBAUD NA NA 2.398 9.548 19.09 73.66 103.12 257.81 515.62 515.62 2.014
FOSC = 10 MHz KBAUD NA 1.202 2.404 9.766 19.53 78.13 NA NA NA 156.3 0.610 FOSC = 3.579 MHz KBAUD 0.301 1.190 2.432 9.322 18.64 NA NA NA NA 55.93 0.218 %ERROR +0.23 -0.83 +1.32 -2.90 -2.90 -- -- -- -- -- -- %ERROR -- +0.16 +0.16 +1.73 +1.73 +1.73 -- -- -- -- --
FOSC = 7.159 MHz
KBAUD NA 1.203 2.380 9.322 18.64 NA NA NA NA 111.9 0.437 %ERROR -- _0.23 -0.83 -2.90 -2.90 -- -- -- -- -- --
FOSC = 5.068 MHz
KBAUD 0.31 1.2 2.4 9.9 19.8 79.2 NA NA NA 79.2 0.309 %ERROR +3.13 0 0 -3.13 +3.13 +3.13 -- -- -- -- --
FOSC = 1 MHz
KBAUD 0.300 1.202 2.232 NA NA NA NA NA NA 15.63 0.061 %ERROR +0.16 +0.16 -6.99 -- -- -- -- -- -- -- --
FOSC = 32.768 kHz
KBAUD 0.256 NA NA NA NA NA NA NA NA 0.512 0.002 %ERROR -14.67 -- -- -- -- -- -- -- -- -- --
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PIC17C7XX
14.2 USART Asynchronous Mode
In this mode, the USART uses standard nonreturn-tozero (NRZ) format (one START bit, eight or nine data bits, and one STOP bit). The most common data format is 8-bits. An on-chip dedicated 8-bit baud rate generator can be used to derive standard baud rate frequencies from the oscillator. The USART's transmitter and receiver are functionally independent but use the same data format and baud rate. The baud rate generator produces a clock x64 of the bit shift rate. Parity is not supported by the hardware, but can be implemented in software (and stored as the ninth data bit). Asynchronous mode is stopped during SLEEP. The Asynchronous mode is selected by clearing the SYNC bit (TXSTA<4>). The USART Asynchronous module consists of the following components: * * * * Baud Rate Generator Sampling Circuit Asynchronous Transmitter Asynchronous Receiver TRMT is a read only bit which is set when the TSR is empty. No interrupt logic is tied to this bit, so the user has to poll this bit in order to determine if the TSR is empty. Note: The TSR is not mapped in data memory, so it is not available to the user.
Transmission is enabled by setting the TXEN (TXSTA<5>) bit. The actual transmission will not occur until TXREG has been loaded with data and the baud rate generator (BRG) has produced a shift clock (Figure 14-3). The transmission can also be started by first loading TXREG and then setting TXEN. Normally, when transmission is first started, the TSR is empty, so a transfer to TXREG will result in an immediate transfer to TSR, resulting in an empty TXREG. A back-to-back transfer is thus possible (Figure 14-4). Clearing TXEN during a transmission will cause the transmission to be aborted. This will reset the transmitter and the TX/CK pin will revert to hi-impedance. In order to select 9-bit transmission, the TX9 (TXSTA<6>) bit should be set and the ninth bit value should be written to TX9D (TXSTA<0>). The ninth bit value must be written before writing the 8-bit data to the TXREG. This is because a data write to TXREG can result in an immediate transfer of the data to the TSR (if the TSR is empty). Steps to follow when setting up an Asynchronous Transmission: 1. 2. 3. 4. 5. 6. 7. Initialize the SPBRG register for the appropriate baud rate. Enable the asynchronous serial port by clearing the SYNC bit and setting the SPEN bit. If interrupts are desired, then set the TXIE bit. If 9-bit transmission is desired, then set the TX9 bit. If 9-bit transmission is selected, the ninth bit should be loaded in TX9D. Load data to the TXREG register. Enable the transmission by setting TXEN (starts transmission).
14.2.1
USART ASYNCHRONOUS TRANSMITTER
The USART transmitter block diagram is shown in Figure 14-1. The heart of the transmitter is the transmit shift register (TSR). The shift register obtains its data from the read/write transmit buffer (TXREG). TXREG is loaded with data in software. The TSR is not loaded until the STOP bit has been transmitted from the previous load. As soon as the STOP bit is transmitted, the TSR is loaded with new data from the TXREG (if available). Once TXREG transfers the data to the TSR (occurs in one TCY at the end of the current BRG cycle), the TXREG is empty and an interrupt bit, TXIF, is set. This interrupt can be enabled/disabled by setting/clearing the TXIE bit. TXIF will be set, regardless of TXIE and cannot be reset in software. It will reset only when new data is loaded into TXREG. While TXIF indicates the status of the TXREG, the TRMT (TXSTA<1>) bit shows the status of the TSR.
FIGURE 14-3:
Write to TXREG BRG Output (Shift Clock) TX (TX/CK pin)
ASYNCHRONOUS MASTER TRANSMISSION
Word 1
START Bit
Bit 0
Bit 1 Word 1
Bit 7/8
STOP Bit
TXIF bit
TRMT bit
Word 1 Transmit Shift Reg
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PIC17C7XX
FIGURE 14-4:
Write to TXREG BRG output (shift clock) TX (TX/CK pin) TXIF bit Word 1 Word 2
ASYNCHRONOUS MASTER TRANSMISSION (BACK TO BACK)
START Bit
Bit 0
Bit 1 Word 1
Bit 7/8
STOP Bit
START Bit Word 2
Bit 0
TRMT bit
Word 1 Transmit Shift Reg.
Word 2 Transmit Shift Reg.
Note: This timing diagram shows two consecutive transmissions.
TABLE 14-6:
Address
REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR
x000 0010 0000 0000 0000 -00x xxxx xxxx
MCLR, WDT
16h, Bank 1 17h, Bank 1 13h, Bank 0 16h, Bank 0 15h, Bank 0 17h, Bank 0 10h, Bank 4 11h, Bank 4 13h, Bank 4 16h, Bank 4 15h, Bank 4 17h, Bank 4 Legend:
PIR1 PIE1 RCSTA1 TXREG1 TXSTA1 SPBRG1 PIR2 PIE2 RCSTA2 TXREG2 TXSTA2 SPBRG2
RBIF RBIE SPEN
TMR3IF TMR2IF
TMR1IF
CA2IF CA2IE --
CA1IF CA1IE FERR
TX1IF TX1IE OERR
RC1IF RC1IE RX9D
u000 0010 0000 0000 0000 -00u uuuu uuuu 0000 --1u 0000 0000 000- 0010 000- 0000 0000 -00u uuuu uuuu 0000 --1u 0000 0000
TMR3IE TMR2IE TMR1IE RX9 SREN CREN
Serial Port Transmit Register (USART1) CSRC TX9 TXEN SYNC -- -- TRMT TX9D
0000 --1x 0000 0000
Baud Rate Generator Register (USART1) SSPIF SSPIE SPEN BCLIF BCLIE RX9 ADIF ADIE SREN -- -- CREN CA4IF CA4IE -- CA3IF CA3IE FERR TX2IF TX2IE OERR RC2IF RC2IE RX9D
000- 0010 000- 0000 0000 -00x xxxx xxxx
Serial Port Transmit Register (USART2) CSRC TX9 TXEN SYNC -- -- TRMT TX9D
0000 --1x 0000 0000
Baud Rate Generator Register (USART2)
x = unknown, u = unchanged, - = unimplemented, read as a '0'. Shaded cells are not used for asynchronous transmission.
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PIC17C7XX
14.2.2 USART ASYNCHRONOUS RECEIVER
ting the receive logic (CREN is set). If the OERR bit is set, transfers from the RSR to RCREG are inhibited, so it is essential to clear the OERR bit if it is set. The framing error bit FERR (RCSTA<2>) is set if a STOP bit is not detected.
The receiver block diagram is shown in Figure 14-2. The data comes in the RX/DT 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 main receive serial shifter operates at the bit rate or at FOSC. Once Asynchronous mode is selected, reception is enabled by setting bit CREN (RCSTA<4>). The heart of the receiver is the receive (serial) shift register (RSR). After sampling the STOP bit, the received data in the RSR is transferred to the RCREG (if it is empty). If the transfer is complete, the interrupt bit, RCIF, is set. The actual interrupt can be enabled/ disabled by setting/clearing the RCIE bit. RCIF is a read only bit which is cleared by the hardware. It is cleared when RCREG has been read and is empty. RCREG is a double buffered register (i.e., it is a twodeep FIFO). It is possible for two bytes of data to be received and transferred to the RCREG FIFO and a third byte begin shifting to the RSR. On detection of the STOP bit of the third byte, if the RCREG is still full, then the overrun error bit, OERR (RCSTA<1>) will be set. The word in the RSR will be lost. RCREG can be read twice to retrieve the two bytes in the FIFO. The OERR bit has to be cleared in software which is done by reset-
Note:
The FERR and the 9th receive bit are buffered the same way as the receive data. Reading the RCREG register will allow the RX9D and FERR bits to be loaded with values for the next received data. Therefore, it is essential for the user to read the RCSTA register before reading RCREG, in order not to lose the old FERR and RX9D information.
14.2.3
SAMPLING
The data on the RX/DT pin is sampled three times by a majority detect circuit to determine if a high or a low level is present at the RX/DT pin. The sampling is done on the seventh, eighth and ninth falling edges of a x16 clock (Figure 14-5). The x16 clock is a free running clock and the three sample points occur at a frequency of every 16 falling edges.
FIGURE 14-5:
RX (RX/DT pin) Baud CLK x16 CLK
RX PIN SAMPLING SCHEME
START bit Baud CLK for all but START bit Bit0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1
2
3
Samples
FIGURE 14-6:
START BIT DETECT
RX (RX/DT pin) x16 CLK First rising edge of x16 clock after RX pin goes low Q2, Q4 CLK RX sampled low START bit
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Steps to follow when setting up an Asynchronous Reception: 1. 2. 3. 4. 5. 6. Initialize the SPBRG register for the appropriate baud rate. Enable the asynchronous serial port by clearing the SYNC bit and setting the SPEN bit. If interrupts are desired, then set the RCIE bit. If 9-bit reception is desired, then set the RX9 bit. Enable the reception by setting the CREN bit. The RCIF bit will be set when reception completes and an interrupt will be generated if the RCIE bit was set. 7. Read RCSTA to get the ninth bit (if enabled) and FERR bit to determine if any error occurred during reception. Read RCREG for the 8-bit received data. If an overrun error occurred, clear the error by clearing the OERR bit. Note: To terminate a reception, either clear the SREN and CREN bits, or the SPEN bit. This will reset the receive logic, so that it will be in the proper state when receive is re-enabled.
8. 9.
FIGURE 14-7:
RX (RX/DT pin) Rcv Shift Reg Rcv Buffer Reg Read Rcv Buffer Reg RCREG RCIF (Interrupt Flag) OERR bit CREN
ASYNCHRONOUS RECEPTION
START bit bit0 bit1 bit7/8 STOP bit START bit bit0 bit7/8 STOP bit START bit bit7/8 STOP bit
Word 1 RCREG
Word 2 RCREG
Word 3
Note: This timing diagram shows three words appearing on the RX input. The RCREG (receive buffer) is read after the third word, causing the OERR (overrun) bit to be set.
TABLE 14-7:
Address
REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR
x000 0010 0000 0000 0000 -00x xxxx xxxx 0000 --1x 0000 0000
MCLR, WDT
16h, Bank 1 17h, Bank 1 13h, Bank 0 14h, Bank 0 15h, Bank 0 17h, Bank 0 10h, Bank 4 11h, Bank 4 13h, Bank 4 14h, Bank 4 15h, Bank 4 17h, Bank 4 Legend:
PIR1 PIE1 RCSTA1 RCREG1 TXSTA1 SPBRG1 PIR2 PIE2 RCSTA2 RCREG2 TXSTA2 SPBRG2
RBIF RBIE SPEN RX7 CSRC
TMR3IF TMR2IF
TMR1IF
CA2IF CA2IE -- RX3 --
CA1IF CA1IE FERR RX2 --
TX1IF TX1IE OERR RX1 TRMT
RC1IF RC1IE RX9D RX0 TX9D
u000 0010 0000 0000 0000 -00u uuuu uuuu 0000 --1u 0000 0000 000- 0010 000- 0000 0000 -00u uuuu uuuu 0000 --1u 0000 0000
TMR3IE TMR2IE TMR1IE RX9 RX6 TX9 SREN RX5 TXEN CREN RX4 SYNC
Baud Rate Generator Register SSPIF SSPIE SPEN RX7 CSRC BCLIF BCLIE RX9 RX6 TX9 ADIF ADIE SREN RX5 TXEN -- -- CREN RX4 SYNC CA4IF CA4IE -- RX3 -- CA3IF CA3IE FERR RX2 -- TX2IF TX2IE OERR RX1 TRMT RC2IF RC2IE RX9D RX0 TX9D
000- 0010 000- 0000 0000 -00x xxxx xxxx 0000 --1x 0000 0000
Baud Rate Generator Register
x = unknown, u = unchanged, - = unimplemented, read as a '0'. Shaded cells are not used for asynchronous reception.
DS30289B-page 126
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PIC17C7XX
14.3 USART Synchronous Master Mode
Clearing TXEN during a transmission will cause the transmission to be aborted and will reset the transmitter. The RX/DT and TX/CK pins will revert to hi-impedance. If either CREN or SREN are set during a transmission, the transmission is aborted and the RX/ DT pin reverts to a hi-impedance state (for a reception). The TX/CK pin will remain an output if the CSRC bit is set (internal clock). The transmitter logic is not reset, although it is disconnected from the pins. In order to reset the transmitter, the user has to clear the TXEN bit. If the SREN bit is set (to interrupt an ongoing transmission and receive a single word), then after the single word is received, SREN will be cleared and the serial port will revert back to transmitting, since the TXEN bit is still set. The DT line will immediately switch from hiimpedance Receive mode to transmit and start driving. To avoid this, TXEN should be cleared. In order to select 9-bit transmission, the TX9 (TXSTA<6>) bit should be set and the ninth bit should be written to TX9D (TXSTA<0>). The ninth bit must be written before writing the 8-bit data to TXREG. This is because a data write to TXREG can result in an immediate transfer of the data to the TSR (if the TSR is empty). If the TSR was empty and TXREG was written before writing the "new" TX9D, the "present" value of TX9D is loaded. Steps to follow when setting up a Synchronous Master Transmission: 1. Initialize the SPBRG register for the appropriate baud rate (see Baud Rate Generator Section for details). Enable the synchronous master serial port by setting the SYNC, SPEN, and CSRC bits. Ensure that the CREN and SREN bits are clear (these bits override transmission when set). If interrupts are desired, then set the TXIE bit (the GLINTD bit must be clear and the PEIE bit must be set). If 9-bit transmission is desired, then set the TX9 bit. If 9-bit transmission is selected, the ninth bit should be loaded in TX9D. Start transmission by loading data to the TXREG register. Enable the transmission by setting TXEN.
In Master Synchronous mode, the data is transmitted in a half-duplex manner; i.e., transmission and reception do not occur at the same time: when transmitting data, the reception is inhibited and vice versa. The synchronous mode is entered by setting the SYNC (TXSTA<4>) bit. In addition, the SPEN (RCSTA<7>) bit is set in order to configure the I/O pins to CK (clock) and DT (data) lines, respectively. The Master mode indicates that the processor transmits the master clock on the CK line. The Master mode is entered by setting the CSRC (TXSTA<7>) bit.
14.3.1
USART SYNCHRONOUS MASTER TRANSMISSION
The USART transmitter block diagram is shown in Figure 14-1. The heart of the transmitter is the transmit (serial) shift register (TSR). The shift register obtains its data from the read/write transmit buffer TXREG. TXREG is loaded with data in software. The TSR is not loaded until the last bit has been transmitted from the previous load. As soon as the last bit is transmitted, the TSR is loaded with new data from TXREG (if available). Once TXREG transfers the data to the TSR (occurs in one TCY at the end of the current BRG cycle), TXREG is empty and the TXIF bit is set. This interrupt can be enabled/disabled by setting/clearing the TXIE bit. TXIF will be set regardless of the state of bit TXIE and cannot be cleared in software. It will reset only when new data is loaded into TXREG. While TXIF indicates the status of TXREG, TRMT (TXSTA<1>) shows the status of the TSR. TRMT is a read only bit which is set when the TSR is empty. No interrupt logic is tied to this bit, so the user has to poll this bit in order to determine if the TSR is empty. The TSR is not mapped in data memory, so it is not available to the user. Transmission is enabled by setting the TXEN (TXSTA<5>) bit. The actual transmission will not occur until TXREG has been loaded with data. The first data bit will be shifted out on the next available rising edge of the clock on the TX/CK pin. Data out is stable around the falling edge of the synchronous clock (Figure 14-9). The transmission can also be started by first loading TXREG and then setting TXEN. This is advantageous when slow baud rates are selected, since BRG is kept in RESET when the TXEN, CREN, and SREN bits are clear. Setting the TXEN bit will start the BRG, creating a shift clock immediately. Normally when transmission is first started, the TSR is empty, so a transfer to TXREG will result in an immediate transfer to the TSR, resulting in an empty TXREG. Back-to-back transfers are possible.
2. 3. 4.
5. 6. 7. 8.
Writing the transmit data to the TXREG, then enabling the transmit (setting TXEN), allows transmission to start sooner than doing these two events in the reverse order. Note: To terminate a transmission, either clear the SPEN bit, or the TXEN bit. This will reset the transmit logic, so that it will be in the proper state when transmit is reenabled.
2000 Microchip Technology Inc.
DS30289B-page 127
PIC17C7XX
TABLE 14-8:
Address
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR
x000 0010 0000 0000 0000 -00x xxxx xxxx 0000 --1x 0000 0000
MCLR, WDT
16h, Bank 1 17h, Bank 1 13h, Bank 0 16h, Bank 0 15h, Bank 0 17h, Bank 0 10h, Bank 4 11h, Bank 4 13h, Bank 4 16h, Bank 4 15h, Bank 4 17h, Bank 4 Legend:
PIR1 PIE1 RCSTA1 TXREG1 TXSTA1 SPBRG1 PIR2 PIE2 RCSTA2 TXREG2 TXSTA2 SPBRG2
RBIF RBIE SPEN TX7 CSRC
TMR3IF TMR2IF
TMR1IF
CA2IF CA2IE -- TX3 --
CA1IF CA1IE FERR TX2 --
TX1IF TX1IE OERR TX1 TRMT
RC1IF RC1IE RX9D TX0 TX9D
u000 0010 0000 0000 0000 -00u uuuu uuuu 0000 --1u 0000 0000 000- 0010 000- 0000 0000 -00u uuuu uuuu 0000 --1u 0000 0000
TMR3IE TMR2IE TMR1IE RX9 TX6 TX9 SREN TX5 TXEN CREN TX4 SYNC
Baud Rate Generator Register SSPIF SSPIE SPEN TX7 CSRC BCLIF BCLIE RX9 TX6 TX9 ADIF ADIE SREN TX5 TXEN -- -- CREN TX4 SYNC CA4IF CA4IE -- TX3 -- CA3IF CA3IE FERR TX2 -- TX2IF TX2IE OERR TX1 TRMT RC2IF RC2IE RX9D TX0 TX9D
000- 0010 000- 0000 0000 -00x xxxx xxxx 0000 --1x 0000 0000
Baud Rate Generator Register
x = unknown, u = unchanged, - = unimplemented, read as a '0'. Shaded cells are not used for synchronous master transmission.
FIGURE 14-8:
SYNCHRONOUS TRANSMISSION
Q3 Q4 Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4 bit7 bit0 Word 2
Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4 bit0 bit1 Word 1 bit2
DT (RX/DT pin) CK (TX/CK pin) Write to TXREG Write Word 1 TXIF Interrupt Flag TRMT
Write Word 2
TXEN
'1'
FIGURE 14-9:
DT (RX/DT pin) CK (TX/CK pin) Write to TXREG
SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
bit0 bit1 bit2 bit6 bit7
TXIF bit
TRMT bit
DS30289B-page 128
2000 Microchip Technology Inc.
PIC17C7XX
14.3.2 USART SYNCHRONOUS MASTER RECEPTION
Steps to follow when setting up a Synchronous Master Reception: 1. 2. 3. 4. 5. 6. Initialize the SPBRG register for the appropriate baud rate. See Section 14.1 for details. Enable the synchronous master serial port by setting bits SYNC, SPEN, and CSRC. If interrupts are desired, then set the RCIE bit. If 9-bit reception is desired, then set the RX9 bit. If a single reception is required, set bit SREN. For continuous reception set bit CREN. The RCIF bit will be set when reception is complete and an interrupt will be generated if the RCIE bit was set. Read RCSTA to get the ninth bit (if enabled) and determine if any error occurred during reception. Read the 8-bit received data by reading RCREG. If any error occurred, clear the error by clearing CREN.
Once Synchronous mode is selected, reception is enabled by setting either the SREN (RCSTA<5>) bit or the CREN (RCSTA<4>) bit. Data is sampled on the RX/ DT pin on the falling edge of the clock. If SREN is set, then only a single word is received. If CREN is set, the reception is continuous until CREN is reset. If both bits are set, then CREN takes precedence. After clocking the last bit, the received data in the Receive Shift Register (RSR) is transferred to RCREG (if it is empty). If the transfer is complete, the interrupt bit RCIF is set. The actual interrupt can be enabled/disabled by setting/clearing the RCIE bit. RCIF is a read only bit which is reset by the hardware. In this case, it is reset when RCREG has been read and is empty. RCREG is a double buffered register; i.e., it is a two deep FIFO. It is possible for two bytes of data to be received and transferred to the RCREG FIFO and a third byte to begin shifting into the RSR. On the clocking of the last bit of the third byte, if RCREG is still full, then the overrun error bit OERR (RCSTA<1>) is set. The word in the RSR will be lost. RCREG can be read twice to retrieve the two bytes in the FIFO. The OERR bit has to be cleared in software. This is done by clearing the CREN bit. If OERR is set, transfers from RSR to RCREG are inhibited, so it is essential to clear the OERR bit if it is set. The 9th receive bit is buffered the same way as the receive data. Reading the RCREG register will allow the RX9D and FERR bits to be loaded with values for the next received data; therefore, it is essential for the user to read the RCSTA register before reading RCREG in order not to lose the old FERR and RX9D information.
7. 8. 9.
Note:
To terminate a reception, either clear the SREN and CREN bits, or the SPEN bit. This will reset the receive logic so that it will be in the proper state when receive is reenabled.
FIGURE 14-10:
SYNCHRONOUS RECEPTION (MASTER MODE, SREN)
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
DT (RX/DT pin) CK (TX/CK pin) Write to the SREN bit SREN bit CREN bit RCIF bit Read RCREG '0'
bit0
bit1
bit2
bit3
bit4
bit5
bit6
bit7
'0'
Note: Timing diagram demonstrates SYNC Master mode with SREN = 1.
2000 Microchip Technology Inc.
DS30289B-page 129
PIC17C7XX
TABLE 14-9:
Address
REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR
x000 0010 0000 0000 0000 -00x xxxx xxxx 0000 --1x 0000 0000
MCLR, WDT
16h, Bank 1 17h, Bank 1 13h, Bank 0 14h, Bank 0 15h, Bank 0 17h, Bank 0 10h, Bank 4 11h, Bank 4 13h, Bank 4 14h, Bank 4 15h, Bank 4 17h, Bank 4 Legend:
PIR1 PIE1 RCSTA1 RCREG1 TXSTA1 SPBRG1 PIR2 PIE2 RCSTA2 RCREG2 TXSTA2 SPBRG2
RBIF RBIE SPEN RX7 CSRC
TMR3IF TMR2IF
TMR1IF
CA2IF CA2IE -- RX3 --
CA1IF CA1IE FERR RX2 --
TX1IF TX1IE OERR RX1 TRMT
RC1IF RC1IE RX9D RX0 TX9D
u000 0010 0000 0000 0000 -00u uuuu uuuu 0000 --1u 0000 0000 000- 0010 000- 0000 0000 -00u uuuu uuuu 0000 --1u 0000 0000
TMR3IE TMR2IE TMR1IE RX9 RX6 TX9 SREN RX5 TXEN CREN RX4 SYNC
Baud Rate Generator Register SSPIF SSPIE SPEN RX7 CSRC BCLIF BCLIE RX9 RX6 TX9 ADIF ADIE SREN RX5 TXEN -- -- CREN RX4 SYNC CA4IF CA4IE -- RX3 -- CA3IF CA3IE FERR RX2 -- TX2IF TX2IE OERR RX1 TRMT RC2IF RC2IE RX9D RX0 TX9D
000- 0010 000- 0000 0000 -00x xxxx xxxx 0000 --1x 0000 0000
Baud Rate Generator Register
x = unknown, u = unchanged, - = unimplemented, read as a '0'. Shaded cells are not used for synchronous master reception.
DS30289B-page 130
2000 Microchip Technology Inc.
PIC17C7XX
14.4 USART Synchronous Slave Mode
14.4.2
The Synchronous Slave mode differs from the Master mode, in the fact that the shift clock is supplied externally at the TX/CK pin (instead of being supplied internally in the Master mode). This allows the device to transfer or receive data in the SLEEP mode. The Slave mode is entered by clearing the CSRC (TXSTA<7>) bit.
USART SYNCHRONOUS SLAVE RECEPTION
Operation of the Synchronous Master and Slave modes are identical except in the case of the SLEEP mode. Also, SREN is a "don't care" in Slave mode. If receive is enabled (CREN) prior to the SLEEP instruction, then a word may be received during SLEEP. On completely receiving the word, the RSR will transfer the data to RCREG (setting RCIF) and if the RCIE bit is set, the interrupt generated will wake the chip from SLEEP. If the global interrupt is enabled, the program will branch to the interrupt vector (0020h). Steps to follow when setting up a Synchronous Slave Reception: 1. Enable the synchronous master serial port by setting the SYNC and SPEN bits and clearing the CSRC bit. If interrupts are desired, then set the RCIE bit. If 9-bit reception is desired, then set the RX9 bit. To enable reception, set the CREN bit. The RCIF bit will be set when reception is complete and an interrupt will be generated if the RCIE bit was set. Read RCSTA to get the ninth bit (if enabled) and determine if any error occurred during reception. Read the 8-bit received data by reading RCREG. If any error occurred, clear the error by clearing the CREN bit.
14.4.1
USART SYNCHRONOUS SLAVE TRANSMIT
The operation of the SYNC Master and Slave modes are identical except in the case of the SLEEP mode. If two words are written to TXREG and then the SLEEP instruction executes, the following will occur. The first word will immediately transfer to the TSR and will transmit as the shift clock is supplied. The second word will remain in TXREG. TXIF will not be set. When the first word has been shifted out of TSR, TXREG will transfer the second word to the TSR and the TXIF flag will now be set. If TXIE is enabled, the interrupt will wake the chip from SLEEP and if the global interrupt is enabled, then the program will branch to the interrupt vector (0020h). Steps to follow when setting up a Synchronous Slave Transmission: 1. Enable the synchronous slave serial port by setting the SYNC and SPEN bits and clearing the CSRC bit. Clear the CREN bit. If interrupts are desired, then set the TXIE bit. If 9-bit transmission is desired, then set the TX9 bit. If 9-bit transmission is selected, the ninth bit should be loaded in TX9D. Start transmission by loading data to TXREG. Enable the transmission by setting TXEN.
2. 3. 4. 5.
6. 7. 8.
2. 3. 4. 5. 6. 7.
Note:
To abort reception, either clear the SPEN bit, or the CREN bit (when in Continuous Receive mode). This will reset the receive logic, so that it will be in the proper state when receive is re-enabled.
Writing the transmit data to the TXREG, then enabling the transmit (setting TXEN), allows transmission to start sooner than doing these two events in the reverse order. Note: To terminate a transmission, either clear the SPEN bit, or the TXEN bit. This will reset the transmit logic, so that it will be in the proper state when transmit is reenabled.
2000 Microchip Technology Inc.
DS30289B-page 131
PIC17C7XX
TABLE 14-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR
x000 0010 0000 0000 0000 -00x 0000 --1x xxxx xxxx 0000 0000
MCLR, WDT
16h, Bank 1 17h, Bank 1 13h, Bank 0 15h, Bank 0 16h, Bank 0 17h, Bank 0 10h, Bank 4 11h, Bank 4 13h, Bank 4 16h, Bank 4 15h, Bank 4 17h, Bank 4 Legend:
PIR1 PIE1 RCSTA1 TXSTA1 TXREG1 SPBRG1 PIR2 PIE2 RCSTA2 TXREG2 TXSTA2 SPBRG2
RBIF RBIE SPEN CSRC TX7
TMR3IF TMR2IF
TMR1IF
CA2IF CA2IE -- -- TX3
CA1IF CA1IE FERR -- TX2
TX1IF TX1IE OERR TRMT TX1
RC1IF RC1IE RX9D TX9D TX0
u000 0010 0000 0000 0000 -00u 0000 --1u uuuu uuuu 0000 0000 000- 0010 000- 0000 0000 -00u uuuu uuuu 0000 --1u 0000 0000
TMR3IE TMR2IE TMR1IE RX9 TX9 TX6 SREN TXEN TX5 CREN SYNC TX4
Baud Rate Generator Register SSPIF SSPIE SPEN TX7 CSRC BCLIF BCLIE RX9 TX6 TX9 ADIF ADIE SREN TX5 TXEN -- -- CREN TX4 SYNC CA4IF CA4IE -- TX3 -- CA3IF CA3IE FERR TX2 -- TX2IF TX2IE OERR TX1 TRMT RC2IF RC2IE RX9D TX0 TX9D
000- 0010 000- 0000 0000 -00x xxxx xxxx 0000 --1x 0000 0000
Baud Rate Generator Register
x = unknown, u = unchanged, - = unimplemented, read as a '0'. Shaded cells are not used for synchronous slave transmission.
TABLE 14-11: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR
x000 0010 0000 0000 0000 -00x xxxx xxxx 0000 --1x 0000 0000
MCLR, WDT
16h, Bank1 17h, Bank1 13h, Bank0 14h, Bank0 15h, Bank 0 17h, Bank 0 10h, Bank 4 11h, Bank 4 13h, Bank 4 14h, Bank 4 15h, Bank 4 17h, Bank 4 Legend:
PIR1 PIE1 RCSTA1 RCREG1 TXSTA1 SPBRG1 PIR2 PIE2 RCSTA2 RCREG2 TXSTA2 SPBRG2
RBIF RBIE SPEN RX7 CSRC
TMR3IF TMR2IF
TMR1IF
CA2IF CA2IE -- RX3 --
CA1IF CA1IE FERR RX2 --
TX1IF TX1IE OERR RX1 TRMT
RC1IF RC1IE RX9D RX0 TX9D
u000 0010 0000 0000 0000 -00u uuuu uuuu 0000 --1u 0000 0000 000- 0010 000- 0000 0000 -00u uuuu uuuu 0000 --1u 0000 0000
TMR3IE TMR2IE TMR1IE RX9 RX6 TX9 SREN RX5 TXEN CREN RX4 SYNC
Baud Rate Generator Register SSPIF SSPIE SPEN RX7 CSRC BCLIF BCLIE RX9 RX6 TX9 ADIF ADIE SREN RX5 TXEN -- -- CREN RX4 SYNC CA4IF CA4IE -- RX3 -- CA3IF CA3IE FERR RX2 -- TX2IF TX2IE OERR RX1 TRMT RC2IF RC2IE RX9D RX0 TX9D
000- 0010 000- 0000 0000 -00x xxxx xxxx 0000 --1x 0000 0000
Baud Rate Generator Register
x = unknown, u = unchanged, - = unimplemented, read as a '0'. Shaded cells are not used for synchronous slave reception.
DS30289B-page 132
2000 Microchip Technology Inc.
PIC17C7XX
15.0 MASTER SYNCHRONOUS SERIAL PORT (MSSP) MODULE
FIGURE 15-2: I2C SLAVE MODE BLOCK DIAGRAM
Internal Data Bus Read SSPBUF reg Shift Clock SSPSR reg SDA MSb LSb Addr Match or General Call Detected Write
The Master Synchronous Serial Port (MSSP) module is a serial interface useful for communicating with other peripheral or microcontroller devices. These peripheral devices may be serial EEPROMs, shift registers, display drivers, A/D converters, etc. The MSSP module can operate in one of two modes: * Serial Peripheral Interface (SPI) * Inter-Integrated CircuitTM (I 2C) Figure 15-1 shows a block diagram for the SPI mode, while Figure 15-2 and Figure 15-3 show the block diagrams for the two different I2C modes of operation.
SCL
Match Detect
FIGURE 15-1:
SPI MODE BLOCK DIAGRAM
Internal Data Bus
SSPADD reg START and STOP bit Detect Set, Reset S, P bits (SSPSTAT reg)
Read SSPBUF reg
Write
FIGURE 15-3:
SSPSR reg SDI SDO bit0 Shift Clock Read SSPADD<6:0> 7 Baud Rate Generator SS Control Enable SS Edge Select 2 Clock Select SSPM3:SSPM0 SMP:CKE 4 TMR2 Output 2 2 Edge Select Prescaler Tosc 4, 16, 64 Data to TX/RX in SSPSR Data Direction bit SDA
I2C MASTER MODE BLOCK DIAGRAM
Internal Data Bus Write
SCL Shift Clock
SSPBUF reg
SSPSR reg MSb LSb Addr Match or General Call Detected
Match detect
SSPADD reg START and STOP bit Set/Clear S bit and Detect/Generate Clear/Set P, bit (SSPSTAT reg) and Set SSPIF
SCK
2000 Microchip Technology Inc.
DS30289B-page 133
PIC17C7XX
REGISTER 15-1: SSPSTAT: SYNC SERIAL PORT STATUS REGISTER (ADDRESS: 13h, BANK 6)
R/W-0 SMP bit 7 bit 7 SMP: 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 I2 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 (Figure 15-6, Figure 15-8 and Figure 15-9) CKP = 0: 1 = Data transmitted on rising edge of SCK 0 = Data transmitted on falling edge of SCK CKP = 1: 1 = Data transmitted on falling edge of SCK 0 = Data transmitted on rising edge of SCK bit 5 D/A: Data/Address bit (I2C mode only) 1 = Indicates that the last byte received or transmitted was data 0 = Indicates that the last byte received or transmitted was address P: STOP bit (I2C mode only. This bit is cleared when the MSSP module is disabled, SSPEN 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 S: START bit (I2C mode only. This bit is cleared when the MSSP module is disabled, SSPEN 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 R/W: Read/Write bit Information (I2C 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 I2 C Slave mode: 1 = Read 0 = Write In I2 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 MSSP is in IDLE mode. bit 1 UA: Update Address (10-bit I2C mode only) 1 = Indicates that the user needs to update the address in the SSPADD register 0 = Address does not need to be updated BF: Buffer Full Status bit Receive (SPI and I2C modes) 1 = Receive complete, SSPBUF is full 0 = Receive not complete, SSPBUF is empty Transmit (I2C mode only) 1 = Data transmit in progress (does not include the ACK and STOP bits), SSPBUF is full 0 = Data transmit complete (does not include the ACK and STOP bits), SSPBUF is empty Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown R/W-0 CKE R-0 D/A R-0 P R-0 S R-0 R/W R-0 UA R-0 BF bit 0
bit 4
bit 3
bit 2
bit 0
DS30289B-page 134
2000 Microchip Technology Inc.
PIC17C7XX
REGISTER 15-2: SSPCON1: SYNC SERIAL PORT CONTROL REGISTER1 (ADDRESS 11h, BANK 6)
R/W-0 WCOL bit 7 bit 7 R/W-0 SSPOV R/W-0 SSPEN R/W-0 CKP R/W-0 SSPM3 R/W-0 SSPM2 R/W-0 SSPM1 R/W-0 SSPM0 bit 0
WCOL: Write Collision Detect bit Master mode: 1 = A write to the SSPBUF register was attempted while the I2C conditions were not valid for a transmission to be started 0 = No collision Slave mode: 1 = The SSPBUF register is written while it is still transmitting the previous word (must be cleared in software) 0 = No collision SSPOV: Receive Overflow Indicator bit In SPI mode: 1 = A new byte is received while the SSPBUF register is still holding the previous data. In case of overflow, the data in SSPSR is lost. Overflow can only occur in Slave mode. In Slave mode, the user must read the SSPBUF, even if only transmitting data, to avoid setting overflow. In Master mode, the overflow bit is not set, since each new reception (and transmission) is initiated by writing to the SSPBUF register. (Must be cleared in software.) 0 = No overflow In I2 C mode: 1 = A byte is received while the SSPBUF register is still holding the previous byte. SSPOV is a "don't care" in Transmit mode. (Must be cleared in software.) 0 = No overflow SSPEN: 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 SCK, SDO, SDI and SS as the source of the serial port pins 0 = Disables serial port and configures these pins as I/O port pins In I2 C mode: 1 = Enables the serial port and configures the SDA and SCL pins as the source of the serial port pins 0 = Disables serial port and configures these pins as I/O port pins Note: In SPI mode, these pins must be properly configured as input or output. 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 I2 C Slave mode: SCK release control 1 = Enable clock 0 = Holds clock low (clock stretch). (Used to ensure data setup time.) In I2 C Master mode: Unused in this mode SSPM3:SSPM0: Synchronous Serial Port Mode Select bits 0000 = SPI Master mode, clock = FOSC/4 0001 = SPI Master mode, clock = FOSC/16 0010 = SPI Master mode, clock = FOSC/64 0011 = SPI Master mode, clock = TMR2 output/2 0100 = SPI Slave mode, clock = SCK pin, SS pin control enabled 0101 = SPI Slave mode, clock = SCK pin, SS pin control disabled, SS can be used as I/O pin 0110 = I2C Slave mode, 7-bit address 0111 = I2C Slave mode, 10-bit address 1000 = I2C Master mode, clock = FOSC / (4 * (SSPADD+1) ) 1xx1 = Reserved 1x1x = Reserved Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
bit 6
bit 5
bit 4
bit 3-0
2000 Microchip Technology Inc.
DS30289B-page 135
PIC17C7XX
REGISTER 15-3: SSPCON2: SYNC SERIAL PORT CONTROL REGISTER2 (ADDRESS 12h, BANK 6)
R/W-0 GCEN bit 7 bit 7 GCEN: General Call Enable bit (in I2C Slave mode only) 1 = Enable interrupt when a general call address (0000h) is received in the SSPSR 0 = General call address disabled ACKSTAT: Acknowledge Status bit (in I2C Master mode only) In Master Transmit mode: 1 = Acknowledge was not received from slave 0 = Acknowledge was received from slave bit 5 ACKDT: Acknowledge Data bit (in I2C Master mode only) In Master Receive mode: Value that will be 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 I2C Master mode only) In Master Receive mode: 1 = Initiate Acknowledge sequence on SDA and SCL pins and transmit AKDT data bit. Automatically cleared by hardware. 0 = Acknowledge sequence idle Note: bit 3 If the I2C module is not in the IDLE mode, this bit may not be set (no spooling) and the SSPBUF may not be written (or writes to the SSPBUF are disabled). R/W-0 ACKSTAT R/W-0 ACKDT R/W-0 ACKEN R/W-0 RCEN R/W-0 PEN R/W-0 RSEN R/W-0 SEN bit 0
bit 6
RCEN: Receive Enable bit (in I2C Master mode only) 1 = Enables Receive mode for I2C 0 = Receive idle Note: If the I2C module is not in the IDLE mode, this bit may not be set (no spooling) and the SSPBUF may not be written (or writes to the SSPBUF are disabled).
bit 2
PEN: STOP Condition Enable bit (in I2C Master mode only) SCK Release Control: 1 = Initiate STOP condition on SDA and SCL pins. Automatically cleared by hardware. 0 = STOP condition idle Note: If the I2C module is not in the IDLE mode, this bit may not be set (no spooling) and the SSPBUF may not be written (or writes to the SSPBUF are disabled).
bit 1
RSEN: Repeated Start Condition Enabled bit (in I2C Master mode only) 1 = Initiate Repeated Start condition on SDA and SCL pins. Automatically cleared by hardware. 0 = Repeated Start condition idle Note: If the I2C module is not in the IDLE mode, this bit may not be set (no spooling) and the SSPBUF may not be written (or writes to the SSPBUF are disabled).
bit 0
SEN: START Condition Enabled bit (In I2C Master mode only) 1 = Initiate START condition on SDA and SCL pins. Automatically cleared by hardware. 0 = START condition idle. Note: If the I2C module is not in the IDLE mode, this bit may not be set (no spooling) and the SSPBUF may not be written (or writes to the SSPBUF are disabled).
Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
DS30289B-page 136
2000 Microchip Technology Inc.
PIC17C7XX
15.1 SPI Mode
FIGURE 15-4:
The SPI mode allows 8-bits of data to be synchronously transmitted and received simultaneously. All four modes of SPI are supported. To accomplish communication, typically three pins are used: * Serial Data Out (SDO) * Serial Data In (SDI) * Serial Clock (SCK) Additionally, a fourth pin may be used when in a Slave mode of operation: * Slave Select (SS)
SDI SDO bit0
MSSP BLOCK DIAGRAM (SPI MODE)
Internal Data Bus
Read SSPBUF reg
Write
SSPSR reg Shift Clock
15.1.1
OPERATION
When initializing the SPI, several options need to be specified. This is done by programming the appropriate control bits in the SSPCON1 register (SSPCON1<5:0>) and SSPSTAT<7:6>. These control bits allow the following to be specified: * * * * Master mode (SCK is the clock output) Slave mode (SCK is the clock input) Clock Polarity (Idle state of SCK) Data Input Sample Phase (middle or end of data output time) * Clock Edge (output data on rising/falling edge of SCK) * Clock Rate (Master mode only) * Slave Select mode (Slave mode only) Figure 15-4 shows the block diagram of the MSSP module when in SPI mode.
SS Control Enable SS Edge Select 2 Clock Select SSPM3:SSPM0 SMP:CKE 4 TMR2 Output 2 2 Edge Select Prescaler Tosc 4, 16, 64 Data to TX/RX in SSPSR Data Direction bit
SCK
The MSSP consists of a transmit/receive Shift Register (SSPSR) and a Buffer register (SSPBUF). The SSPSR shifts the data in and out of the device, MSb first. The SSPBUF holds the data that was written to the SSPSR, until the received data is ready. Once the 8-bits of data have been received, that byte is moved to the SSPBUF register. Then the buffer full detect bit BF (SSPSTAT<0>) and the interrupt flag bit SSPIF (PIR2<7>) are set. This double buffering of the received data (SSPBUF) allows the next byte to start reception before reading the data that was just received. Any write to the SSPBUF register during transmission/reception of data will be ignored, and the write collision detect bit WCOL (SSPCON1<7>) will be set. User software must clear the WCOL bit so that it can be determined if the following write(s) to the SSPBUF register completed successfully.
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DS30289B-page 137
PIC17C7XX
When the application software is expecting to receive valid data, the SSPBUF should be read before the next byte of data to transfer is written to the SSPBUF. Buffer full bit, BF (SSPSTAT<0>), indicates when SSPBUF has been loaded with the received data (transmission is complete). When the SSPBUF is read, bit BF is cleared. This data may be irrelevant if the SPI is only a transmitter. Generally the MSSP interrupt is used to determine when the transmission/reception has completed. The SSPBUF must be read and/or written. If the interrupt method is not going to be used, then software polling can be done to ensure that a write collision does not occur. Example 15-1 shows the loading of the SSPBUF (SSPSR) for data transmission.
15.1.2
ENABLING SPI I/O
To enable the serial port, MSSP Enable bit, SSPEN (SSPCON1<5>), must be set. To reset or reconfigure SPI mode, clear bit SSPEN, re-initialize the SSPCON registers and then set bit SSPEN. This configures the SDI, SDO, SCK and SS pins as serial port pins. For the pins to behave as the serial port function, some must have their data direction bits (in the DDR register) appropriately programmed. That is: * * * * * SDI is automatically controlled by the SPI module SDO must have DDRB<7> cleared SCK (Master mode) must have DDRB<6> cleared SCK (Slave mode) must have DDRB<6> set SS must have PORTA<2> set
EXAMPLE 15-1:
LOADING THE SSPBUF (SSPSR) REGISTER
Bank 6 Has data been received (transmit complete)? No Save in user RAM New data to xmit
MOVLB 6 LOOP BTFSS SSPSTAT, BF
; ; ; ; ; GOTO LOOP ; MOVPF SSPBUF, RXDATA ; MOVFP TXDATA, SSPBUF ;
Any serial port function that is not desired may be overridden by programming the corresponding data direction (DDR) register to the opposite value.
15.1.3
TYPICAL CONNECTION
The SSPSR is not directly readable, or writable and can only be accessed by addressing the SSPBUF register. Additionally, the MSSP status register (SSPSTAT) indicates the various status conditions.
Figure 15-5 shows a typical connection between two microcontrollers. The master controller (Processor 1) initiates the data transfer by sending the SCK signal. Data is shifted out of both shift registers on their programmed clock edge and latched on the opposite edge of the clock. Both processors should be programmed to same Clock Polarity (CKP), then both controllers would send and receive data at the same time. Whether the data is meaningful (or dummy data) depends on the application software. This leads to three scenarios for data transmission: * Master sends data -- Slave sends dummy data * Master sends data -- Slave sends data * Master sends dummy data -- Slave sends data
FIGURE 15-5:
SPI MASTER/SLAVE CONNECTION
SPI Master SSPM3:SSPM0 = 00xxb SDO SDI
SPI Slave SSPM3:SSPM0 = 010xb
Serial Input Buffer (SSPBUF)
Serial Input Buffer (SSPBUF)
Shift Register (SSPSR) MSb LSb
SDI
SDO
Shift Register (SSPSR) MSb LSb
Serial Clock SCK PROCESSOR 1 SCK PROCESSOR 2
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2000 Microchip Technology Inc.
PIC17C7XX
15.1.4 MASTER MODE
The master can initiate the data transfer at any time because it controls the SCK. The master determines when the slave (Processor 2, Figure 15-5) is to broadcast data by the software protocol. In Master mode, the data is transmitted/received as soon as the SSPBUF register is written to. If the SPI is only going to receive, the SDO output could be disabled (programmed as an input). The SSPSR register will continue to shift in the signal present on the SDI pin at the programmed clock rate. As each byte is received, it will be loaded into the SSPBUF register as if a normal received byte (interrupts and status bits appropriately set). This could be useful in receiver applications as a "Line Activity Monitor" mode. The clock polarity is selected by appropriately programming bit CKP (SSPCON1<4>). This then, would give waveforms for SPI communication as shown in Figure 15-6, Figure 15-8 and Figure 15-9, where the MSb is transmitted first. In Master mode, the SPI clock rate (bit rate) is user programmable to be one of the following: * * * * FOSC/4 (or TCY) FOSC/16 (or 4 * TCY) FOSC/64 (or 16 * TCY) Timer2 output/2
This allows a maximum bit clock frequency (at 33 MHz) of 8.25 MHz. Figure 15-6 shows the waveforms for Master mode. When CKE = 1, the SDO data is valid before there is a clock edge on SCK. The change of the input sample is shown based on the state of the SMP bit. The time when the SSPBUF is loaded with the received data is shown.
FIGURE 15-6:
Write to SSPBUF SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) SCK (CKP = 0 CKE = 1) SCK (CKP = 1 CKE = 1) SDO (CKE = 0) SDO (CKE = 1) SDI (SMP = 0) Input Sample (SMP = 0) SDI (SMP = 1) Input Sample (SMP = 1) SSPIF SSPSR to SSPBUF
SPI MODE WAVEFORM (MASTER MODE)
4 clock modes
bit7 bit7
bit6 bit6
bit5 bit5
bit4 bit4
bit3 bit3
bit2 bit2
bit1 bit1
bit0 bit0
bit7
bit0
bit7
bit0
Next Q4 cycle after Q2
2000 Microchip Technology Inc.
DS30289B-page 139
PIC17C7XX
15.1.5 SLAVE MODE
In Slave mode, the data is transmitted and received as the external clock pulses appear on SCK. When the last bit is latched, the interrupt flag bit SSPIF (PIR2<7>) is set. While in Slave mode, the external clock is supplied by the external clock source on the SCK pin. This external clock must meet the minimum high and low times as specified in the electrical specifications. While in SLEEP mode, the slave can transmit/receive data. When a byte is received, the device will wake-up from SLEEP. the SDO pin is driven. When the SS pin goes high, the SDO pin is no longer driven, even if in the middle of a transmitted byte and becomes a floating output. External pull-up/pull-down resistors may be desirable, depending on the application. Note 1: When the SPI is in Slave mode with SS pin control enabled (SSPCON<3:0> = 0100), the SPI module will reset if the SS pin is set to VDD. 2: If the SPI is used in Slave mode with CKE = '1', then the SS pin control must be enabled. When the SPI module resets, the bit counter is forced to 0. This can be done by either forcing the SS pin to a high level, or clearing the SSPEN bit. To emulate two-wire communication, the SDO pin can be connected to the SDI pin. When the SPI needs to operate as a receiver, the SDO pin can be configured as an input. This disables transmissions from the SDO. The SDI can always be left as an input (SDI function), since it cannot create a bus conflict.
15.1.6
SLAVE SELECT SYNCHRONIZATION
The SS pin allows a Synchronous Slave mode. The SPI must be in Slave mode with SS pin control enabled (SSPCON1<3:0> = 04h). The pin must not be driven low for the SS pin to function as an input. The RA2 Data Latch must be high. When the SS pin is low, transmission and reception are enabled and
FIGURE 15-7:
SS
SLAVE SYNCHRONIZATION WAVEFORM
SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0)
Write to SSPBUF
SDO
bit7
bit6
bit7
bit0
SDI (SMP = 0) Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF
bit0 bit7 bit7
Next Q4 cycle after Q2
DS30289B-page 140
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 15-8:
SS optional SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) Write to SSPBUF SDO SDI (SMP = 0) Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0
SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0)
bit7
bit0
Next Q4 cycle after Q2
FIGURE 15-9:
SS not optional SCK (CKP = 0 CKE = 1) SCK (CKP = 1 CKE = 1) Write to SSPBUF SDO SDI (SMP = 0) Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF
SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1)
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
bit7
bit0
Next Q4 cycle after Q2
2000 Microchip Technology Inc.
DS30289B-page 141
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15.1.7 SLEEP OPERATION
In Master mode, all module clocks are halted, and the transmission/reception will remain in that state until the device wakes from SLEEP. After the device returns to normal mode, the module will continue to transmit/ receive data. In 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 MSSP interrupt flag bit will be set and if enabled, will wake the device from SLEEP.
15.1.8
EFFECTS OF A RESET
A RESET disables the MSSP module and terminates the current transfer.
TABLE 15-1:
Address
REGISTERS ASSOCIATED WITH SPI OPERATION
Name Bit 7 PEIF SSPIF SSPIE Bit 6 T0CKIF BCLIF BCLIE Bit 5 T0IF ADIF ADIE Bit 4 INTF -- -- Bit 3 PEIE CA4IF CA4IE Bit 2 T0CKIE CA3IF CA3IE Bit 1 T0IE TX2IF TX2IE Bit 0 INTE RC2IF RC2IE POR, BOR MCLR, WDT
07h, Unbanked INTSTA 10h, Bank 4 11h, Bank 4 14h, Bank 6 11h, Bank 6 13h, Bank 6 PIR2 PIE2 SSPBUF
0000 0000 0000 0000 000- 0010 000- 0010 000- 0000 000- 0000 xxxx xxxx uuuu uuuu
Synchronous Serial Port Receive Buffer/Transmit Register CKP P SSPM3 SSPM2 S R/W SSPM1 UA
SSPCON1 WCOL SSPOV SSPEN SSPSTAT SMP CKE D/A
SSPM0 0000 0000 0000 0000 BF
0000 0000 0000 0000
Legend: x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the SSP in SPI mode.
DS30289B-page 142
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PIC17C7XX
15.2 MSSP I2 C Operation
FIGURE 15-11:
The MSSP module in I 2C mode fully implements all master and slave functions (including general call support) and provides interrupts on START and STOP bits in hardware to determine a free bus (multi-master function). The MSSP module implements the standard mode specifications as well as 7-bit and 10-bit addressing. Refer to Application Note AN578, "Use of the SSP Module in the I 2C Multi-Master Environment." A "glitch" filter is on the SCL and SDA pins when the pin is an input. This filter operates in both the 100 kHz and 400 kHz modes. In the 100 kHz mode, when these pins are an output, there is a slew rate control of the pin that is independent of device frequency.
I2C MASTER MODE BLOCK DIAGRAM
Internal Data Bus
Read SSPADD<6:0> 7 Baud Rate Generator SSPBUF reg Shift Clock SSPSR reg SDA MSb
Write
SCL
LSb Addr Match
FIGURE 15-10:
I2C SLAVE MODE BLOCK DIAGRAM
Internal Data Bus
Match Detect
SSPADD reg START and STOP bit Set/Clear S bit and Detect/Generate Clear/Set P, bit (SSPSTAT reg) and Set SSPIF
Read SSPBUF reg Shift Clock SSPSR reg SDA MSb
Write
SCL
LSb Addr Match
Match Detect
Two pins are used for data transfer. These are the SCL pin, which is the clock and the SDA pin, which is the data. The SDA and SCL pins are automatically configured when the I2C mode is enabled. The SSP module functions are enabled by setting SSP Enable bit SSPEN (SSPCON1<5>). The MSSP module has six registers for I2C operation. These are the:
SSPADD reg START and STOP bit Detect Set, Reset S, P bits (SSPSTAT reg)
* * * * *
SSP Control Register1 (SSPCON1) SSP Control Register2 (SSPCON2) SSP Status Register (SSPSTAT) Serial Receive/Transmit Buffer (SSPBUF) SSP Shift Register (SSPSR) - Not directly accessible * SSP Address Register (SSPADD) The SSPCON1 register allows control of the I 2C operation. Four mode selection bits (SSPCON1<3:0>) allow one of the following I 2C modes to be selected: * I 2C Slave mode (7-bit address) * I 2C Slave mode (10-bit address) * I 2C Master mode, clock = OSC/4 (SSPADD +1) Before selecting any I 2C mode, the SCL and SDA pins must be programmed to inputs by setting the appropriate DDR bits. Selecting an I 2C mode, by setting the SSPEN bit, enables the SCL and SDA pins to be used as the clock and data lines in I 2C mode.
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DS30289B-page 143
PIC17C7XX
The SSPSTAT register gives the status of the data transfer. This information includes detection of a START or STOP bit, specifies if the received byte was data or address if the next byte is the completion of 10-bit address and if this will be a read or write data transfer. The SSPBUF is the register to which transfer data is written to or read from. The SSPSR register shifts the data in or out of the device. In receive operations, the SSPBUF and SSPSR create a doubled buffered receiver. This allows reception of the next byte to begin before reading the last byte of received data. When the complete byte is received, it is transferred to the SSPBUF register and flag bit SSPIF is set. If another complete byte is received before the SSPBUF register is read, a receiver overflow has occurred and bit SSPOV (SSPCON1<6>) is set and the byte in the SSPSR is lost. The SSPADD register holds the slave address. In 10-bit mode, the user needs to write the high byte of the address (1111 0 A9 A8 0). Following the high byte address match, the low byte of the address needs to be loaded (A7:A0).
15.2.1
SLAVE MODE
In Slave mode, the SCL and SDA pins must be configured as inputs. The MSSP module will override the input state with the output data when required (slavetransmitter). When an address is matched or the data transfer after an address match is received, the hardware automatically will generate the acknowledge (ACK) pulse and then load the SSPBUF register with the received value currently in the SSPSR register. There are certain conditions that will cause the MSSP module not to give this ACK pulse. These are if either (or both): a) b) The buffer full bit BF (SSPSTAT<0>) was set before the transfer was received. The overflow bit SSPOV (SSPCON1<6>) was set before the transfer was received.
If the BF bit is set, the SSPSR register value is not loaded into the SSPBUF, but bit SSPIF and SSPOV are set. Table 15-2 shows what happens when a data transfer byte is received, given the status of bits BF and SSPOV. The shaded cells show the condition where user software did not properly clear the overflow condition. Flag bit BF is cleared by reading the SSPBUF register, while bit SSPOV is cleared through software. The SCL clock input must have a minimum high and low time for proper operation. The high and low times of the I2C specification, as well as the requirement of the MSSP module, are shown in timing parameter #100 and parameter #101 of the Electrical Specifications.
DS30289B-page 144
2000 Microchip Technology Inc.
PIC17C7XX
15.2.1.1 Addressing
5. Once the MSSP module has been enabled, it waits for a START condition to occur. Following the START condition, the 8-bits are shifted into the SSPSR register. All incoming bits are sampled with the rising edge of the clock (SCL) line. The value of register SSPSR<7:1> is compared to the value of the SSPADD register. The address is compared on the falling edge of the eighth clock (SCL) pulse. If the addresses match and the BF and SSPOV bits are clear, the following events occur: a) The SSPSR register value is loaded into the SSPBUF register on the falling edge of the 8th SCL pulse. The buffer full bit, BF, is set on the falling edge of the 8th SCL pulse. An ACK pulse is generated. SSP interrupt flag bit, SSPIF (PIR2<7>), is set (interrupt is generated if enabled) - on the falling edge of the 9th SCL pulse. Update the SSPADD register with the first (high) byte of Address. This will clear bit UA and release the SCL line. Read the SSPBUF register (clears bit BF) and clear flag bit SSPIF. Receive Repeated Start condition. Receive first (high) byte of Address (bits SSPIF and BF are set). Read the SSPBUF register (clears bit BF) and clear flag bit SSPIF. Note: Following the Repeated Start condition (step 7) in 10-bit mode, the user only needs to match the first 7-bit address. The user does not update the SSPADD for the second half of the address.
6. 7. 8. 9.
b) c) d)
15.2.1.2
Slave Reception
In 10-bit address mode, two address bytes need to be received by the slave. The five Most Significant bits (MSbs) of the first address byte specify if this is a 10-bit address. Bit R/W (SSPSTAT<2>) must specify a write so the slave device will receive the second address byte. For a 10-bit address, the first byte would equal `1111 0 A9 A8 0', where A9 and A8 are the two MSbs of the address. The sequence of events for a 10-bit address is as follows, with steps 7- 9 for slave-transmitter: 1. 2. Receive first (high) byte of Address (bits SSPIF, BF and bit UA (SSPSTAT<1>) are set). Update the SSPADD register with second (low) byte of Address (clears bit UA and releases the SCL line). Read the SSPBUF register (clears bit BF) and clear flag bit SSPIF. Receive second (low) byte of Address (bits SSPIF, BF and UA are set).
When the R/W bit of the address byte is clear and an address match occurs, the R/W bit of the SSPSTAT register is cleared. The received address is loaded into the SSPBUF register. When the address byte overflow condition exists, then no acknowledge (ACK) pulse is given. An overflow condition is defined as either bit BF (SSPSTAT<0>) is set, or bit SSPOV (SSPCON1<6>) is set. An SSP interrupt is generated for each data transfer byte. Flag bit SSPIF (PIR2<7>) must be cleared in software. The SSPSTAT register is used to determine the status of the received byte. Note: The SSPBUF will be loaded if the SSPOV bit is set and the BF flag is cleared. If a read of the SSPBUF was performed, but the user did not clear the state of the SSPOV bit before the next receive occurred, the ACK is not sent and the SSPBUF is updated.
3. 4.
TABLE 15-2:
DATA TRANSFER RECEIVED BYTE ACTIONS
SSPSR SSPBUF Generate ACK Pulse Set bit SSPIF (SSP Interrupt occurs if enabled)
Status Bits as Data Transfer is Received BF SSPOV
0 0 Yes Yes Yes 1 0 No No Yes 1 1 No No Yes 0 1 Yes No Yes Note 1: Shaded cells show the conditions where the user software did not properly clear the overflow condition.
2000 Microchip Technology Inc.
DS30289B-page 145
PIC17C7XX
15.2.1.3 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 SSPSTAT register is set. The received address is loaded into the SSPBUF register. The ACK pulse will be sent on the ninth bit, and the SCL pin is held low. The transmit data must be loaded into the SSPBUF register, which also loads the SSPSR register. Then SCL pin should be enabled by setting bit CKP (SSPCON1<4>). The master must monitor the SCL pin prior to asserting another clock pulse. The slave devices may be holding off the master by stretching the clock. The eight data bits are shifted out on the falling edge of the SCL input. This ensures that the SDA signal is valid during the SCL high time (Figure 15-13). An SSP interrupt is generated for each data transfer byte. The SSPIF flag bit must be cleared in software, and the SSPSTAT register is used to determine the status of the byte transfer. The SSPIF flag bit is set on the falling edge of the ninth clock pulse. As a slave-transmitter, the ACK pulse from the masterreceiver is latched on the rising edge of the ninth SCL input pulse. If the SDA line was high (not ACK), then the data transfer is complete. When the not ACK is latched by the slave, the slave logic is reset and the slave then monitors for another occurrence of the START bit. If the SDA line was low (ACK), the transmit data must be loaded into the SSPBUF register, which also loads the SSPSR register. Then, the SCL pin should be enabled by setting the CKP bit.
FIGURE 15-12:
I 2C WAVEFORMS FOR RECEPTION (7-BIT ADDRESS)
R/W = 0 ACK Not Receiving Data Receiving Data ACK ACK 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 P
Receiving Address SDA A7 A6 A5 A4 A3 A2 A1 1 2 3 4 5 6 7
SCL SSPIF
S
8
9
Bus Master Terminates Transfer Cleared in software SSPBUF register is read
BF (SSPSTAT<0>)
SSPOV (SSPCON1<6>) Bit SSPOV is set because the SSPBUF register is still full. ACK is not sent.
FIGURE 15-13:
I 2C WAVEFORMS FOR TRANSMISSION (7-BIT ADDRESS)
Receiving Address R/W = 1 ACK A1 D7 D6 D5 D4 R/W = 0 Transmitting Data D3 D2 D1 D0 Not ACK
SDA
A7
A6
A5
A4
A3
A2
SCL
S
1 2 Data in sampled
3
4
5
6
7
8
9
1 SCL held low while CPU responds to SSPIF
2
3
4
5
6
7
8
9
P
SSPIF BF (SSPSTAT<0>) Cleared in software SSPBUF is written in software CKP (SSPCON1<4>) Set bit after writing to SSPBUF (the SSPBUF must be written to before the CKP bit can be set) From SSP Interrupt Service Routine
DS30289B-page 146
2000 Microchip Technology Inc.
FIGURE 15-14:
2000 Microchip Technology Inc.
Master sends NACK Transmit is complete Clock is held low until update of SSPADD has taken place Receive Second Byte of Address Receive First Byte of Address R/W=1 ACK ACK 1 1 1 1 0 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 Transmitting Data Byte D7 D6 D5 D4 D3 D2 D1 D0 ACK A9 A8 ACK 6 6 Sr 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 7 8 9 1 2 3 4 5 6 7 8 9 P CKP has to be set for clock to be released Cleared in software Cleared in software Cleared in software Bus Master terminates transfer Dummy read of SSPBUF to clear BF flag Dummy read of SSPBUF to clear BF flag Write of SSPBUF initiates transmit Cleared by hardware when SSPADD is updated. UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated.
Receive First Byte of Address R/W = 0
SDA
1
1
1
1
0
SCL
S
1
2
3
4
5
SSPIF
(PIR1<3>)
BF (SSPSTAT<0>)
SSPBUF is written with contents of SSPSR
I2C SLAVE-TRANSMITTER (10-BIT ADDRESS)
UA (SSPSTAT<1>)
UA is set indicating that the SSPADD needs to be updated
PIC17C7XX
DS30289B-page 147
FIGURE 15-15:
DS30289B-page 148
Clock is held low until update of SSPADD has taken place R/W = 0 A8 ACK A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 ACK D3 Receive Second Byte of Address Receive Data Byte D2 D1 R/W = 1 D0 ACK Bus Master terminates transfer 1 1 0 A9 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 P Cleared in software Cleared in software
PIC17C7XX
Receive First Byte of Address
SDA
1
1
SCL
S
1
2
SSPIF
(PIR1<3>)
BF (SSPSTAT<0>) SSPBUF is written with contents of SSPSR Dummy read of SSPBUF to clear BF flag Dummy read of SSPBUF to clear BF flag Read of SSPBUF clears BF flag
I2C SLAVE-RECEIVER (10-BIT ADDRESS)
UA (SSPSTAT<1>) UA is set indicating that the SSPADD needs to be updated Cleared by hardware when SSPADD is updated with low byte of address. UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with high byte of address.
2000 Microchip Technology Inc.
PIC17C7XX
15.2.2 GENERAL CALL ADDRESS SUPPORT
The addressing procedure for the I2C bus is such that the first byte after the START condition usually determines which device will be the slave addressed by the master. The exception is the general call address, which can address all devices. When this address is used, all devices should, in theory, respond with an acknowledge. The general call address is one of eight addresses reserved for specific purposes by the I2C protocol. It consists of all 0's with R/W = 0. The general call address is recognized when the General Call Enable bit (GCEN) is enabled (SSPCON2<7> is set). Following a START bit detect, 8-bits are shifted into SSPSR and the address is compared against SSPADD and is also compared to the general call address, fixed in hardware. If the general call address matches, the SSPSR is transferred to the SSPBUF, the BF flag is set (eighth bit) and on the falling edge of the ninth bit (ACK bit), the SSPIF flag is set. When the interrupt is serviced, the source for the interrupt can be checked by reading the contents of the SSPBUF to determine if the address was device specific, or a general call address. In 10-bit mode, the SSPADD is required to be updated for the second half of the address to match and the UA bit is set (SSPSTAT<1>). If the general call address is sampled when GCEN is set, while the slave is configured in 10-bit address mode, then the second half of the address is not necessary, the UA bit will not be set and the slave will begin receiving data after the acknowledge (Figure 15-16).
FIGURE 15-16:
SLAVE MODE GENERAL CALL ADDRESS SEQUENCE (7 OR 10-BIT MODE)
Address is compared to General Call Address after ACK, set Interrupt R/W = 0 ACK D7 Receiving Data D6 D5 D4 D3 D2 D1 D0 ACK
SDA SCL S SSPIF BF (SSPSTAT<0>) 1
General Call Address
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
Cleared in Software SSPBUF is Read SSPOV (SSPCON1<6>) '0'
GCEN (SSPCON2<7>)
'1'
2000 Microchip Technology Inc.
DS30289B-page 149
PIC17C7XX
15.2.3 SLEEP OPERATION
I2C
15.2.4
EFFECTS OF A RESET
While in SLEEP mode, the module can receive addresses or data and when an address match or complete byte transfer occurs, wake the processor from SLEEP (if the SSP interrupt is enabled).
A RESET disables the SSP module and terminates the current transfer.
TABLE 15-3:
Address
REGISTERS ASSOCIATED WITH I2C OPERATION
Name Bit 7 PEIF SSPIF SSPIE Bit 6 T0CKIF BCLIF BCLIE Bit 5 T0IF ADIF ADIE Bit 4 INTF -- -- Bit 3 PEIE CA4IF CA4IE Bit 2 T0CKIE CA3IF CA3IE Bit 1 T0IE TX2IF TX2IE Bit 0 INTE RC2IF RC2IE POR, BOR
0000 0000 000- 0000 000- 0000 0000 0000 xxxx xxxx
MCLR, WDT
0000 0000 000- 0000 000- 0000 0000 0000 uuuu uuuu 0000 0000 0000 0000 0000 0000
07h, Unbanked INTSTA 10h, Bank 4 11h, Bank 4 10h. Bank 6 14h, Bank 6 11h, Bank 6 12h, Bank 6 13h, Bank 6 Legend: PIR2 PIE2 SSPADD SSPBUF SSPCON1 SSPCON2 SSPSTAT
Synchronous Serial Port (I2C mode) Address Register Synchronous Serial Port Receive Buffer/Transmit Register WCOL GCEN SMP SSPOV ACKSTAT CKE SSPEN ACKDT D/A CKP ACKEN P SSPM3 RCEN S SSPM2 PEN R/W SSPM1 RSEN UA SSPM0 SEN BF
0000 0000 0000 0000 0000 0000
x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used by the SSP in I2C mode.
DS30289B-page 150
2000 Microchip Technology Inc.
PIC17C7XX
15.2.5 MASTER MODE
Master mode of operation is supported by interrupt generation on the detection of the START and STOP conditions. The STOP (P) and START (S) bits are cleared from a RESET, or when the MSSP module is disabled. Control of the I 2C bus may be taken when the P bit is set, or the bus is idle, with both the S and P bits clear. In Master mode, the SCL and SDA lines are manipulated by the MSSP hardware. The following events will cause SSP Interrupt Flag bit, SSPIF, to be set (SSP Interrupt if enabled): * * * * * START condition STOP condition Data transfer byte transmitted/received Acknowledge transmit Repeated Start
FIGURE 15-17:
SSP BLOCK DIAGRAM (I2C MASTER MODE)
Internal Data Bus Read SSPBUF Write Baud Rate Generator Clock Arbitrate/WCOL Detect (hold off clock source) DS30289B-page 151 Shift Clock SSPSR Receive Enable MSb LSb SSPM3:SSPM0 SSPADD<6:0>
SDA SDA In
SCL
SCL In Bus Collision
START bit Detect, STOP bit Detect Write Collision Detect Clock Arbitration State Counter for end of XMIT/RCV
Set/Reset, S, P, WCOL (SSPSTAT) Set SSPIF, BCLIF Reset ACKSTAT, PEN (SSPCON2)
2000 Microchip Technology Inc.
Clock Cntl
START bit, STOP bit, Acknowledge Generate
PIC17C7XX
15.2.6 MULTI-MASTER MODE 15.2.7.1 I2C Master Mode Operation
In Multi-Master mode, the interrupt generation on the detection of the START and STOP conditions allows the determination of when the bus is free. The STOP (P) and START (S) bits are cleared from a RESET, or when the MSSP module is disabled. Control of the I 2C bus may be taken when bit P (SSPSTAT<4>) is set, or the bus is idle, with both the S and P bits clear. When the bus is busy, enabling the SSP interrupt will generate the interrupt when the STOP condition occurs. In Multi-Master operation, the SDA line must be monitored for arbitration, to see if the signal level is the expected output level. This check is performed in hardware, with the result placed in the BCLIF bit. The states where arbitration can be lost are: * * * * * Address Transfer Data Transfer A START Condition A Repeated Start Condition An Acknowledge Condition 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 I2C bus will not be released. In Master Transmitter mode, serial data is output through SDA, while SCL 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 transmitted, an acknowledge bit is received. START and STOP conditions are output to indicate the beginning and the end of a serial transfer. In Master Receive mode, the first byte transmitted contains the slave address of the transmitting device (7 bits) and the R/W bit. In this case, the R/W bit will be logic '1'. Thus, the first byte transmitted is a 7-bit slave address, followed by a '1' to indicate receive bit. Serial data is received via SDA, while SCL outputs the serial clock. Serial data is received 8 bits at a time. After each byte is received, an acknowledge bit is transmitted. START and STOP conditions indicate the beginning and end of transmission. The baud rate generator used for SPI mode operation is now used to set the SCL clock frequency for either 100 kHz, 400 kHz, or 1 MHz I2C operation. The baud rate generator reload value is contained in the lower 7 bits of the SSPADD register. The baud rate generator will automatically begin counting on a write to the SSPBUF. Once the given operation is complete (i.e., transmission of the last data bit is followed by ACK), the internal clock will automatically stop counting and the SCL pin will remain in its last state
15.2.7
I2C MASTER MODE SUPPORT
Master mode is enabled by setting and clearing the appropriate SSPM bits in SSPCON1 and by setting the SSPEN bit. Once Master mode is enabled, the user has six options. * Assert a START condition on SDA and SCL. * Assert a Repeated Start condition on SDA and SCL. * Write to the SSPBUF register initiating transmission of data/address. * Generate a STOP condition on SDA and SCL. * Configure the I2C port to receive data. * Generate an Acknowledge condition at the end of a received byte of data. The MSSP Module, when configured in I2C Master mode, does not allow queueing of events. For instance: The user is not allowed to initiate a START condition and immediately write the SSPBUF register to initiate transmission before the START condition is complete. In this case, the SSPBUF will not be written to and the WCOL bit will be set, indicating that a write to the SSPBUF did not occur.
Note:
DS30289B-page 152
2000 Microchip Technology Inc.
PIC17C7XX
A typical transmit sequence would go as follows: a) b) The user generates a START Condition by setting the START enable bit (SEN) in SSPCON2. SSPIF is set. The module will wait the required START time before any other operation takes place. The user loads the SSPBUF with address to transmit. Address is shifted out the SDA pin until all 8 bits are transmitted. The MSSP Module shifts in the ACK bit from the slave device and writes its value into the SSPCON2 register (SSPCON2<6>). The module generates an interrupt at the end of the ninth clock cycle by setting SSPIF. The user loads the SSPBUF with eight bits of data. DATA is shifted out the SDA pin until all 8 bits are transmitted. The MSSP Module shifts in the ACK bit from the slave device, and writes its value into the SSPCON2 register (SSPCON2<6>). The MSSP module generates an interrupt at the end of the ninth clock cycle by setting the SSPIF bit. The user generates a STOP condition by setting the STOP enable bit PEN in SSPCON2. Interrupt is generated once the STOP condition is complete.
15.2.8
I2C
BAUD RATE GENERATOR
c) d) e)
In Master mode, the reload value for the BRG is located in the lower 7 bits of the SSPADD register (Figure 15-18). When the BRG is loaded with this value, the BRG counts down to 0 and stops until another reload has taken place. The BRG count is decremented twice per instruction cycle (TCY), on the Q2 and Q4 clock. In I2C Master mode, the BRG is reloaded automatically. If Clock Arbitration is taking place, for instance, the BRG will be reloaded when the SCL pin is sampled high (Figure 15-19).
f) g) h) i)
FIGURE 15-18:
SSPM3:SSPM0
BAUD RATE GENERATOR BLOCK DIAGRAM
SSPADD<6:0>
SSPM3:SSPM0 SCL CLKOUT
Reload Control
Reload
j)
BRG Down Counter
FOSC/4
k) l)
FIGURE 15-19:
SDA
BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION
DX DX-1 SCL allowed to transition high.
SCL de-asserted but slave holds SCL low (clock arbitration). SCL
BRG decrements (on Q2 and Q4 cycles). BRG Value 03h 02h 01h 00h (hold off) 03h 02h
SCL is sampled high, reload takes place and BRG starts its count. BRG Reload
2000 Microchip Technology Inc.
DS30289B-page 153
PIC17C7XX
15.2.9 I2C MASTER MODE START CONDITION TIMING 15.2.9.1 WCOL Status Flag
If the user writes the SSPBUF when a START sequence is in progress, then WCOL is set and the contents of the buffer are unchanged (the write doesn't occur). Note: Because queueing of events is not allowed, writing to the lower 5 bits of SSPCON2 is disabled until the START condition is complete.
To initiate a START condition, the user sets the START condition enable bit, SEN (SSPCON2<0>). If the SDA and SCL pins are sampled high, the baud rate generator is reloaded with the contents of SSPADD<6:0> and starts its count. If SCL and SDA are both sampled high when the baud rate generator times out (TBRG), the SDA pin is driven low. The action of the SDA being driven low while SCL is high is the START condition and causes the S bit (SSPSTAT<3>) to be set. Following this, the baud rate generator is reloaded with the contents of SSPADD<6:0> and resumes its count. When the baud rate generator times out (TBRG), the SEN bit (SSPCON2<0>) will be automatically cleared by hardware, the baud rate generator is suspended, leaving the SDA line held low and the START condition is complete. Note: If at the beginning of START condition, the SDA and SCL pins are already sampled low, or if during the START condition, the SCL line is sampled low before the SDA line is driven low, a bus collision occurs. The Bus Collision Interrupt Flag (BCLIF) is set, the START condition is aborted and the I2C module is reset into its IDLE state.
FIGURE 15-20:
FIRST START BIT TIMING
Write to SEN bit occurs here. SDA = 1, SCL = 1 Set S bit (SSPSTAT<3>) At completion of START bit, Hardware clears SEN bit and sets SSPIF bit. TBRG Write to SSPBUF occurs here. 1st Bit SDA TBRG 2nd Bit
TBRG
SCL S
TBRG
DS30289B-page 154
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 15-21: START CONDITION FLOW CHART
SSPEN = 1, SSPCON1<3:0> = 1000
Idle Mode
SEN (SSPCON2<0> = 1)
Bus Collision Detected, Set BCLIF, Release SCL, Clear SEN
No
SDA = 1? SCL = 1? Yes Load BRG with SSPADD<6:0>
No
Yes SCL= 0?
No SDA = 0?
No
BRG Rollover?
Yes
Yes
Reset BRG
Force SDA = 0, Load BRG with SSPADD<6:0>, Set S bit.
No
SCL = 0?
No
BRG Rollover?
Yes
Yes
Reset BRG Force SCL = 0, START Condition Done, Clear SEN and set SSPIF
2000 Microchip Technology Inc.
DS30289B-page 155
PIC17C7XX
15.2.10 I2C MASTER MODE REPEATED START CONDITION TIMING
Immediately following the SSPIF bit getting set, the user may write the SSPBUF with the 7-bit address in 7bit mode, or the default first address in 10-bit mode. After the first eight bits are transmitted and an ACK is received, the user may then transmit an additional eight bits of address (10-bit mode), or eight bits of data (7-bit mode).
A Repeated Start condition occurs when the RSEN bit (SSPCON2<1>) is programmed high and the I2C module is in the idle state. When the RSEN bit is set, the SCL pin is asserted low. When the SCL pin is sampled low, the baud rate generator is loaded with the contents of SSPADD<6:0> and begins counting. The SDA pin is released (brought high) for one baud rate generator count (TBRG). When the baud rate generator times out, if SDA is sampled high, the SCL pin will be de-asserted (brought high). When SCL is sampled high the baud rate generator is reloaded with the contents of SSPADD<6:0> and begins counting. SDA and SCL must be sampled high for one TBRG. This action is then followed by assertion of the SDA pin (SDA is low) for one TBRG while SCL is high. Following this, the RSEN bit in the SSPCON2 register will be automatically cleared and the baud rate generator is not reloaded, leaving the SDA pin held low. As soon as a START condition is detected on the SDA and SCL pins, the S bit (SSPSTAT<3>) will be set. The SSPIF bit will not be set until the baud rate generator has timed out. Note 1: If the 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: * SDA is sampled low when SCL goes from low to high. * SCL goes low before SDA is asserted low. This may indicate that another master is attempting to transmit a data "1".
15.2.10.1
WCOL status flag
If the user writes the SSPBUF when a Repeated Start sequence is in progress, then WCOL is set and the contents of the buffer are unchanged (the write doesn't occur). Note: Because queueing of events is not allowed, writing of the lower 5 bits of SSPCON2 is disabled until the Repeated Start condition is complete.
FIGURE 15-22:
REPEAT START CONDITION WAVEFORM
Set S (SSPSTAT<3>) Write to SSPCON2 occurs here. SDA = 1, SCL (no change) SDA = 1, SCL = 1 At completion of START bit, hardware clear RSEN bit and set SSPIF TBRG 1st Bit SDA Falling edge of ninth clock End of Xmit Write to SSPBUF occurs here TBRG TBRG Sr = Repeated Start
TBRG
TBRG
SCL
DS30289B-page 156
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 15-23: REPEATED START CONDITION FLOW CHART (PAGE 1)
Start B
Idle Mode, SSPEN = 1, SSPCON1<3:0> = 1000
RSEN = 1
Force SCL = 0
No SCL = 0?
Yes Release SDA, Load BRG with SSPADD<6:0>
BRG Rollover?
No
Yes
Release SCL
(Clock Arbitration) SCL = 1? No
Yes
Bus Collision, Set BCLIF, Release SDA, Clear RSEN
No SDA = 1?
Yes
Load BRG with SSPADD<6:0>
C
A
2000 Microchip Technology Inc.
DS30289B-page 157
PIC17C7XX
FIGURE 15-24: REPEATED START CONDITION FLOW CHART (PAGE 2)
B C
Yes No No SCL = 1? SDA = 0? Yes Reset BRG Force SDA = 0, Load BRG with SSPADD<6:0> No BRG Rollover? Yes
A
Set S
No
SCL = '0'?
No
BRG Rollover?
Yes
Yes Force SCL = 0, Repeated Start condition done, Clear RSEN, Set SSPIF.
Reset BRG
DS30289B-page 158
2000 Microchip Technology Inc.
PIC17C7XX
15.2.11 I2C MASTER MODE TRANSMISSION 15.2.11.1 BF Status Flag
In Transmit mode, the BF bit (SSPSTAT<0>) is set when the CPU writes to SSPBUF and is cleared when all 8 bits are shifted out.
Transmission of a data byte, a 7-bit address, or either half of a 10-bit address, is accomplished by simply writing a value to SSPBUF register. This action will set the buffer full flag (BF) and allow the baud rate generator to begin counting and start the next transmission. Each bit of address/data will be shifted out onto the SDA pin after the falling edge of SCL is asserted (see data hold time spec). SCL is held low for one baud rate generator roll over count (TBRG). Data should be valid before SCL is released high (see Data setup time spec). When the SCL pin is released high, it is held that way for TBRG, the data on the SDA pin must remain stable for that duration and some hold time after the next falling edge of SCL. After the eighth bit is shifted out (the falling edge of the eighth clock), the BF flag is cleared and the master releases SDA, allowing the slave device being addressed to respond with an ACK bit during the ninth bit time, if an address match occurs or if data was received properly. The status of ACK is read into the ACKDT on the falling edge of the ninth clock. If the master receives an acknowledge, the acknowledge status bit (AKSTAT) is cleared. If not, the bit is set. After the ninth clock, the SSPIF is set and the master clock (baud rate generator) is suspended until the next data byte is loaded into the SSPBUF, leaving SCL low and SDA unchanged (Figure 15-26). After the write to the SSPBUF, each bit of address will be shifted out on the falling edge of SCL until all seven address bits and the R/W bit are completed. On the falling edge of the eighth clock, the master will de-assert the SDA pin, allowing the slave to respond with an acknowledge. On the falling edge of the ninth clock, the master will sample the SDA pin to see if the address was recognized by a slave. The status of the ACK bit is loaded into the ACKSTAT status bit (SSPCON2<6>). Following the falling edge of the ninth clock transmission of the address, the SSPIF is set, the BF flag is cleared and the baud rate generator is turned off until another write to the SSPBUF takes place, holding SCL low and allowing SDA to float.
15.2.11.2
WCOL Status Flag
If the user writes the SSPBUF when a transmit is already in progress (i.e., SSPSR is still shifting out a data byte), then WCOL is set and the contents of the buffer are unchanged (the write doesn't occur). WCOL must be cleared in software.
15.2.11.3
AKSTAT Status Flag
In Transmit mode, the AKSTAT bit (SSPCON2<6>) is cleared when the slave has sent an acknowledge (ACK = 0) and is set when the slave does not acknowledge (ACK = 1). A slave sends an acknowledge when it has recognized its address (including a general call), or when the slave has properly received its data.
2000 Microchip Technology Inc.
DS30289B-page 159
PIC17C7XX
FIGURE 15-25: MASTER TRANSMIT FLOW CHART
Idle Mode
Write SSPBUF
Num_Clocks = 0, BF = 1
Force SCL = 0
Num_Clocks = 8? No Load BRG with SSPADD<6:0>, Start BRG Count, SDA = Current Data bit
Yes
Release SDA so Slave can drive ACK, Force BF = 0
Load BRG with SSPADD<6:0>, start BRG count
BRG Rollover?
No
BRG Rollover?
No
Yes Yes Stop BRG, Force SCL = 1 Force SCL = 1, Stop BRG
(Clock Arbitration) SCL = 1? No
(Clock Arbitration)
SCL = 1?
No
Yes Yes Read SDA and place into ACKSTAT bit (SSPCON2<6>) No Bus Collision Detected Set BCLIF, Hold Prescale Off, Clear XMIT Enable
SDA = Data bit?
Yes Load BRG with SSPADD<6:0>, Count SCL High Time
Load BRG with SSPADD<6:0>, Count High Time
No Rollover? Yes BRG Rollover? No SCL = 0? No SDA = Data bit? No Yes
Yes Yes Num_Clocks = Num_Clocks + 1 Reset BRG
Force SCL = 0, Set SSPIF
DS30289B-page 160
2000 Microchip Technology Inc.
FIGURE 15-26:
Write SSPCON2<0> SEN = 1 START Condition Begins From Slave Clear ACKSTAT bit SSPCON2<6> R/W = 0 A1 D7 D6 D5 D4 D3 D2 ACK = 0 Transmitting Data or Second Half of 10-bit Address D1 D0 SEN = 0 Transmit Address to Slave SDA SSPBUF Written with 7-bit Address and R/W Start Transmit SCL S 1 2 3 4 5 6 7 8 9 1 SCL held low while CPU Responds to SSPIF 2 3 4 5 6 7 8 A7 A6 A5 A4 A3 A2
2000 Microchip Technology Inc.
ACKSTAT in SSPCON2 = 1 ACK 9 P SSPIF Cleared in Software Cleared in Software Service Routine From SSP interrupt Cleared in Software BF (SSPSTAT<0>) SSPBUF Written SEN After START Condition SEN Cleared by Hardware. SSPBUF is Written in Software PEN R/W
I 2C MASTER MODE TIMING (TRANSMISSION, 7 OR 10-BIT ADDRESS)
PIC17C7XX
DS30289B-page 161
PIC17C7XX
15.2.12 I2C MASTER MODE RECEPTION 15.2.12.1 BF Status Flag
Master mode reception is enabled by programming the receive enable bit, RCEN (SSPCON2<3>). Note: The SSP Module must be in an IDLE STATE before the RCEN bit is set, or the RCEN bit will be disregarded. In receive operation, BF is set when an address or data byte is loaded into SSPBUF from SSPSR. It is cleared when SSPBUF is read.
15.2.12.2
SSPOV Status Flag
The baud rate generator begins counting and on each rollover, the state of the SCL pin changes (high to low/ low to high) and data is shifted into the SSPSR. After the falling edge of the eighth clock, the receive enable flag is automatically cleared, the contents of the SSPSR are loaded into the SSPBUF, the BF flag is set, the SSPIF is set and the baud rate generator is suspended from counting, holding SCL low. The SSP is now in IDLE state, awaiting the next command. When the buffer is read by the CPU, the BF flag is automatically cleared. The user can then send an acknowledge bit at the end of reception, by setting the acknowledge sequence enable bit, ACKEN (SSPCON2<4>).
In receive operation, SSPOV is set when 8 bits are received into the SSPSR, and the BF flag is already set from a previous reception.
15.2.12.3
WCOL Status Flag
If the user writes the SSPBUF when a receive is already in progress (i.e., SSPSR is still shifting in a data byte), then WCOL is set and the contents of the buffer are unchanged (the write doesn't occur).
DS30289B-page 162
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 15-27: MASTER RECEIVER FLOW CHART
Idle Mode RCEN = 1
Num_Clocks = 0, Release SDA
Force SCL=0, Load BRG w/ SSPADD<6:0>, Start Count
BRG Rollover? Yes Release SCL
No
(Clock Arbitration) SCL = 1? No
Yes Sample SDA, Shift Data into SSPSR
Load BRG with SSPADD<6:0>, Start Count.
BRG Rollover? Yes
No
SCL = 0?
No
Yes
Num_Clocks = Num_Clocks + 1
No Num_Clocks = 8? Yes Force SCL = 0, Set SSPIF, Set BF. Move Contents of SSPSR into SSPBUF, Clear RCEN.
2000 Microchip Technology Inc.
DS30289B-page 163
FIGURE 15-28:
DS30289B-page 164
Write to SSPCON2<4> to Start Acknowledge Sequence SDA = ACKDT (SSPCON2<5>) = 0 Master Configured as a Receiver by Programming SSPCON2<3>, (RCEN = 1) ACK from Slave R/W = 1 A1 D7 D1 D0 D7 D1 D6 D4 D3 D6 D4 D3 ACK D5 D5 D2 D0 D2 ACK Receiving Data from Slave Receiving Data from Slave ACK RCEN cleared automatically RCEN = 1 Start Next Receive RCEN Cleared Automatically ACK from Master SDA = ACKDT = 0 Set ACKEN, Start Acknowledge Sequence SDA = ACKDT = 1 PEN bit = 1 Written Here A4 A3 A2 ACK is Not Sent 4 5 1 2 3 4 5 1 2 3 4 5 6 8 6 7 8 9 7 9 6 7 8 9 Set SSPIF at End of Receive Bus Master Terminates Transfer P Set SSPIF Interrupt at End of Acknowledge sequence Data Shifted in on Falling Edge of CLK Set SSPIF interrupt at end of receive Set SSPIF Interrupt at End of Acknowledge Sequence Cleared in Software Cleared in Software Cleared in software Cleared in software Set P bit (SSPSTAT<4>) and SSPIF Last bit is shifted into SSPSR and contents are unloaded into SSPBUF
PIC17C7XX
Write to SSPCON2<0> (SEN = 1) Begin START Condition
SEN = 0 Write to SSPBUF Occurs Here Start XMIT
Transmit Address to Slave
SDA
A7
A6
A5
SCL
S
1
2
3
SSPIF
SDA = 0, SCL = 1 while CPU Responds to SSPIF
Cleared in Software
BF (SSPSTAT<0>)
I 2C MASTER MODE TIMING (RECEPTION 7-BIT ADDRESS)
SSPOV SSPOV is Set Because SSPBUF is Still Full
2000 Microchip Technology Inc.
ACKEN
PIC17C7XX
15.2.13 ACKNOWLEDGE SEQUENCE TIMING 15.2.13.1 WCOL Status Flag
If the user writes the SSPBUF when an acknowledge sequence is in progress, then WCOL is set and the contents of the buffer are unchanged (the write doesn't occur).
An acknowledge sequence is enabled by setting the acknowledge sequence enable bit, ACKEN (SSPCON2<4>). When this bit is set, the SCL pin is pulled low and the contents of the acknowledge data bit is presented on the SDA 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 (TBRG), and the SCL pin is de-asserted (pulled high). When the SCL pin is sampled high (clock arbitration), the baud rate generator counts for TBRG. The SCL pin is then pulled low. Following this, the ACKEN bit is automatically cleared, the baud rate generator is turned off and the SSP module then goes into IDLE mode (Figure 15-29).
FIGURE 15-29:
ACKNOWLEDGE SEQUENCE WAVEFORM
ACKEN Automatically Cleared
Acknowledge Sequence Starts Here, Write to SSPCON2 ACKEN = 1, ACKDT = 0 TBRG SDA D0 ACK TBRG
SCL
8
9
SSPIF
Set SSPIF at the End of Receive
Cleared in Software
Cleared in Software Set SSPIF at the End of Acknowledge Sequence
Note: TBRG = one baud rate generator period.
2000 Microchip Technology Inc.
DS30289B-page 165
PIC17C7XX
FIGURE 15-30: ACKNOWLEDGE FLOW CHART
Idle Mode
Set ACKEN
Force SCL = 0 BRG Rollover? No No SCL = 0? Yes Yes Drive ACKDT bit (SSPCON2<5>) onto SDA pin, Load BRG with SSPADD<6:0>, Start Count. SCL = 0? Reset BRG Force SCL = 0, Clear ACKEN Set SSPIF Yes
No
No ACKDT = 1?
Yes No BRG Rollover? Yes Yes Force SCL = 1 SDA = 1? No
No (Clock Arbitration)
Bus Collision Detected, Set BCLIF, Release SCL, Clear ACKEN SCL = 1?
Yes Load BRG with SSPADD <6:0>, Start Count.
DS30289B-page 166
2000 Microchip Technology Inc.
PIC17C7XX
15.2.14 STOP CONDITION TIMING 15.2.14.1 WCOL Status Flag
A STOP bit is asserted on the SDA pin at the end of a receive/transmit by setting the Stop Sequence Enable bit PEN (SSPCON2<2>). At the end of a receive/ transmit the SCL line is held low after the falling edge of the ninth clock. When the PEN bit is set, the master will assert the SDA line low. When the SDA line is sampled low, the baud rate generator is reloaded and counts down to `0'. When the baud rate generator times out, the SCL pin will be brought high and one TBRG (baud rate generator rollover count) later, the SDA pin will be de-asserted. When the SDA pin is sampled high while SCL is high, the P bit (SSPSTAT<4>) is set. A TBRG later, the PEN bit is cleared and the SSPIF bit is set (Figure 15-31). Whenever the firmware decides to take control of the bus, it will first determine if the bus is busy by checking the S and P bits in the SSPSTAT register. If the bus is busy, then the CPU can be interrupted (notified) when a STOP bit is detected (i.e., bus is free). If the user writes the SSPBUF when a STOP sequence is in progress, then WCOL is set and the contents of the buffer are unchanged (the write doesn't occur).
FIGURE 15-31:
STOP CONDITION RECEIVE OR TRANSMIT MODE
Write to SSPCON2 Set PEN Falling Edge of 9th Clock TBRG SCL
SCL = 1 for TBRG, followed by SDA = 1 for TBRG after SDA sampled high. P bit (SSPSTAT<4>) is set. PEN bit (SSPCON2<2>) is cleared by hardware and the SSPIF bit is set.
SDA
ACK
P
TBRG TBRG TBRG SCL brought high after TBRG. SDA asserted low before rising edge of clock to setup STOP condition.
Note: TBRG = one baud rate generator period.
2000 Microchip Technology Inc.
DS30289B-page 167
PIC17C7XX
FIGURE 15-32: STOP CONDITION FLOW CHART
Idle Mode, SSPEN = 1, SSPCON1<3:0> = 1000
PEN = 1
Start BRG
Force SDA = 0 SCL Doesn't Change BRG Rollover?
No
No SDA = 0?
Yes Release SDA, Start BRG
Yes Start BRG BRG Rollover? No
BRG Rollover?
No
Yes Bus Collision Detected, Set BCLIF, Clear PEN
No Yes De-assert SCL, SCL = 1 P bit Set?
Yes SDA going from 0 to 1 while SCL = 1 Set SSPIF, STOP Condition done, PEN cleared
(Clock Arbitration) SCL = 1? No
Yes
DS30289B-page 168
2000 Microchip Technology Inc.
PIC17C7XX
15.2.15 CLOCK ARBITRATION 15.2.16 SLEEP OPERATION
Clock arbitration occurs when the master, during any receive, transmit, or Repeated Start/Stop condition, deasserts the SCL pin (SCL allowed to float high). When the SCL pin is allowed to float high, the baud rate generator (BRG) is suspended from counting until the SCL pin is actually sampled high. When the SCL pin is sampled high, the baud rate generator is reloaded with the contents of SSPADD<6:0> and begins counting. This ensures that the SCL 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 15-33). While in SLEEP mode, the I2C module can receive addresses or data and when an address match or complete byte transfer occurs, wake the processor from SLEEP (if the SSP interrupt is enabled).
15.2.17
EFFECTS OF A RESET
A RESET disables the SSP module and terminates the current transfer.
FIGURE 15-33:
CLOCK ARBITRATION TIMING IN MASTER TRANSMIT MODE
BRG Overflow, Release SCL, If SCL = 1 Load BRG with SSPADD<6:0>, and Start Count to measure high time interval.
BRG overflow occurs, Release SCL, Slave device holds SCL low.
SCL = 1 BRG starts counting clock high interval.
SCL SCL line sampled once every machine cycle (TOSC * 4). Hold off BRG until SCL is sampled high.
SDA TBRG TBRG TBRG
2000 Microchip Technology Inc.
DS30289B-page 169
PIC17C7XX
15.2.18 MULTI -MASTER COMMUNICATION, BUS COLLISION AND BUS ARBITRATION
If a START, Repeated Start, STOP, or Acknowledge condition was in progress when the bus collision occurred, the condition is aborted, the SDA and SCL lines are de-asserted and the respective control bits in the SSPCON2 register are cleared. When the user services the bus collision Interrupt Service Routine, and if the I2C bus is free, the user can resume communication by asserting a START condition. The master will continue to monitor the SDA and SCL pins and if a STOP condition occurs, the SSPIF bit will be set. A write to the SSPBUF will start the transmission of data at the first data bit, regardless of where the transmitter left off when bus collision occurred. In Multi-Master mode, the interrupt generation on the detection of START and STOP conditions allows the determination of when the bus is free. Control of the I2C bus can be taken when the P bit is set in the SSPSTAT register, or the bus is idle and the S and P bits are cleared.
Multi-Master mode support is achieved by bus arbitration. When the master outputs address/data bits onto the SDA pin, arbitration takes place when the master outputs a '1' on SDA, by letting SDA float high and another master asserts a '0'. When the SCL pin floats high, data should be stable. If the expected data on SDA is a '1' and the data sampled on the SDA pin = '0', then a bus collision has taken place. The master will set the Bus Collision Interrupt Flag, BCLIF and reset the I2C port to its IDLE state (Figure 15-34). If a transmit was in progress when the bus collision occurred, the transmission is halted, the BF flag is cleared, the SDA and SCL lines are de-asserted and the SSPBUF can be written to. When the user services the bus collision Interrupt Service Routine and if the I2C bus is free, the user can resume communication by asserting a START condition.
FIGURE 15-34:
BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE
Data changes while SCL = 0. SDA line pulled low by another source. SDA released by master. Sample SDA. While SCL is high data doesn't match what is driven by the master. Bus collision has occurred.
SDA
SCL
Set bus collision interrupt.
BCLIF
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PIC17C7XX
15.2.18.1 Bus Collision During a START Condition
During a START condition, a bus collision occurs if: a) b) SDA or SCL are sampled low at the beginning of the START condition (Figure 15-35). SCL is sampled low before SDA is asserted low (Figure 15-36). If the SDA pin is sampled low during this count, the BRG is reset and the SDA line is asserted early (Figure 15-37). If, however, a '1' is sampled on the SDA pin, the SDA pin is asserted low at the end of the BRG count. The baud rate generator is then reloaded and counts down to 0 and during this time, if the SCL pin is sampled as '0', a bus collision does not occur. At the end of the BRG count, the SCL pin is asserted low. Note: The reason that bus collision is not a factor during a START condition is that no two bus masters can assert a START condition at the exact same time. Therefore, one master will always assert SDA before the other. This condition does not cause a bus collision because the two masters must be allowed to arbitrate the first address following the START condition and if the address is the same, arbitration must be allowed to continue into the data portion, Repeated Start, or Stop conditions.
During a START condition, both the SDA and the SCL pins are monitored. If: the SDA pin is already low or the SCL pin is already low, then: the START condition is aborted, and the BCLIF flag is set, and the SSP module is reset to its IDLE state (Figure 15-35). The START condition begins with the SDA and SCL pins de-asserted. When the SDA pin is sampled high, the baud rate generator is loaded from SSPADD<6:0> and counts down to `0'. If the SCL pin is sampled low while SDA is high, a bus collision occurs, because it is assumed that another master is attempting to drive a data '1' during the START condition.
FIGURE 15-35:
BUS COLLISION DURING START CONDITION (SDA ONLY)
SDA goes low before the SEN bit is set. . Set BCLIF, S bit and SSPIF set because SDA = 0, SCL = 1.
SDA
SCL Set SEN, enable START condition if SDA = 1, SCL=1. SEN SDA sampled low before START condition. Set BCLIF. S bit and SSPIF set because SDA = 0, SCL = 1. SSPIF and BCLIF are cleared in software. S SEN cleared automatically because of bus collision. SSP module reset into IDLE state.
BCLIF
SSPIF
SSPIF and BCLIF are cleared in software.
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PIC17C7XX
FIGURE 15-36: BUS COLLISION DURING START CONDITION (SCL = 0)
SDA = 0, SCL = 1 TBRG SDA TBRG
SCL
Set SEN, enable START sequence if SDA = 1, SCL = 1. SCL = 0 before SDA = 0, Bus collision occurs, Set BCLIF. SCL = 0 before BRG time-out, Bus collision occurs, Set BCLIF.
SEN
BCLIF Interrupts cleared in software. S SSPIF '0' '0' '0' '0'
FIGURE 15-37:
BRG RESET DUE TO SDA COLLISION DURING START CONDITION
SDA = 0, SCL = 1 Set S Less than TBRG TBRG SDA pulled low by other master. Reset BRG and assert SDA. Set SSPIF
SDA
SCL
S
SCL pulled low after BRG Time-out. Set SEN, enable START sequence if SDA = 1, SCL = 1.
SEN
BCLIF
'0'
S
SSPIF SDA = 0, SCL = 1 Set SSPIF. Interrupts cleared in software.
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PIC17C7XX
15.2.18.2 Bus Collision During a Repeated Start Condition
During a Repeated Start condition, a bus collision occurs if: a) b) A low level is sampled on SDA when SCL goes from low level to high level. SCL goes low before SDA is asserted low, indicating that another master is attempting to transmit a data '1'. reloaded and begins counting. If SDA goes from high to low before the BRG times out, no bus collision occurs because no two masters can assert SDA at exactly the same time. If, however, SCL goes from high to low before the BRG times out and SDA has not already been asserted, then a bus collision occurs. In this case, another master is attempting to transmit a data '1' during the Repeated Start condition. If, at the end of the BRG time-out, both SCL and SDA are still high, the SDA pin is driven low, the BRG is reloaded and begins counting. At the end of the count, regardless of the status of the SCL pin, the SCL pin is driven low and the Repeated Start condition is complete (Figure 15-38).
When the user de-asserts SDA and the pin is allowed to float high, the BRG is loaded with SSPADD<6:0> and counts down to `0'. The SCL pin is then deasserted and when sampled high, the SDA pin is sampled. If SDA is low, a bus collision has occurred (i.e., another master is attempting to transmit a data '0'). If, however, SDA is sampled high, then the BRG is
FIGURE 15-38:
SDA
BUS COLLISION DURING A REPEATED START CONDITION (CASE 1)
SCL
Sample SDA when SCL goes high. If SDA = 0, set BCLIF and release SDA and SCL. RSEN
BCLIF Cleared in software. '0' '0'
S SSPIF
'0' '0'
FIGURE 15-39:
BUS COLLISION DURING REPEATED START CONDITION (CASE 2)
TBRG TBRG
SDA SCL SCL goes low before SDA, Set BCLIF. Release SDA and SCL. Interrupt cleared in software. RSEN S SSPIF '0' '0' '0' '0'
BCLIF
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15.2.18.3 Bus Collision During a STOP Condition
Bus collision occurs during a STOP condition if: a) After the SDA pin has been de-asserted and allowed to float high, SDA is sampled low after the BRG has timed out. After the SCL pin is de-asserted, SCL is sampled low before SDA goes high. The STOP condition begins with SDA asserted low. When SDA is sampled low, the SCL pin is allowed to float. When the pin is sampled high (clock arbitration), the baud rate generator is loaded with SSPADD<6:0> and counts down to `0'. After the BRG times out, SDA is sampled. If SDA is sampled low, a bus collision has occurred. This is due to another master attempting to drive a data '0'. If the SCL pin is sampled low before SDA is allowed to float high, a bus collision occurs. This is another case of another master attempting to drive a data '0' (Figure 15-40).
b)
FIGURE 15-40:
BUS COLLISION DURING A STOP CONDITION (CASE 1)
TBRG TBRG TBRG SDA sampled low after TBRG, Set BCLIF.
SDA SDA asserted low. SCL PEN BCLIF P SSPIF '0' '0' '0' '0'
FIGURE 15-41:
BUS COLLISION DURING A STOP CONDITION (CASE 2)
TBRG TBRG TBRG
SDA Assert SDA. SCL PEN BCLIF P SSPIF '0' '0' SCL goes low before SDA goes high. Set BCLIF.
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PIC17C7XX
15.3 Connection Considerations for I2C Bus
example, with a supply voltage of VDD = 5V +10% and VOL max = 0.4V at 3 mA, Rp min = (5.5-0.4)/0.003 = 1.7 k. VDD as a function of Rp is shown in Figure 1542. The desired noise margin of 0.1 VDD for the low level, limits the maximum value of Rs. Series resistors are optional and used to improve ESD susceptibility. The bus capacitance is the total capacitance of wire, connections and pins. This capacitance limits the maximum value of Rp due to the specified rise time (Figure 15-42). The SMP bit is the slew rate control enabled bit. This bit is in the SSPSTAT register and controls the slew rate of the I/O pins when in I2C mode (master or slave).
For standard mode I2C bus devices, the values of resistors Rp Rs in Figure 15-42 depends on the following parameters: * Supply voltage * Bus capacitance * Number of connected devices (input current + leakage current) The supply voltage limits the minimum value of resistor Rp due to the specified minimum sink current of 3 mA at VOL max = 0.4V for the specified output stages. For
FIGURE 15-42:
SAMPLE DEVICE CONFIGURATION FOR I2C BUS
VDD + 10%
Rp
Rp
DEVICE
Rs
Rs
SDA SCL Cb = 10 - 400 pF
Note: I2C devices with input levels related to VDD must have one common supply line to which the pull-up resistor is also connected.
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PIC17C7XX
15.4 Example Program
Example 15-2 shows MPLAB(R) C17 'C' code for using the I2C module in Master mode to communicate with a 24LC01B serial EEPROM. This example uses the PICmicro(R) 'C' libraries included with MPLAB C17.
EXAMPLE 15-2:
INTERFACING TO A 24LC01B SERIAL EEPROM (USING MPLAB C17)
// Include necessary header files #include // Processor header file #include // Delay routines header file #include // Standard Library header file #include // I2C routines header file #define CONTROL 0xa0 // Control byte definition for 24LC01B
// Function declarations void main(void); void WritePORTD(static unsigned char data); void ByteWrite(static unsigned char address,static unsigned char data); unsigned char ByteRead(static unsigned char address); void ACKPoll(void); // Main program void main(void) { static unsigned char address; static unsigned char datao; static unsigned char datai; address = 0; OpenI2C(MASTER,SLEW_ON); SSPADD = 39;
// I2C address of 24LC01B // Data written to 24LC01B // Data read from 24LC01B // Preset address to 0 // Configure I2C Module Master mode, Slew rate control on // Configure clock for 100KHz
while(address<128) // Loop 128 times, 24LC01B is 128x8 { datao = PORTB; do { ByteWrite(address,datao); // Write data to EEPROM ACKPoll(); // Poll the 24LC01B for state datai = ByteRead(address); // Read data from EEPROM into SSPBUF } while(datai != datao); // Loop as long as data not correctly // written to 24LC01B address++; } while(1) { Nop(); } } // Increment address // Done writing 128 bytes to 24LC01B, Loop forever
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PIC17C7XX
EXAMPLE 15-2: INTERFACING TO A 24LC01B SERIAL EEPROM (USING MPLAB C17)
// Writes the byte data to 24LC01B at the specified address void ByteWrite(static unsigned char address, static unsigned char data) { StartI2C(); // Send start bit IdleI2C(); // Wait for idle condition WriteI2C(CONTROL); // Send control byte IdleI2C(); // Wait for idle condition if (!SSPCON2bits.ACKSTAT) // If 24LC01B ACKs { WriteI2C(address); // Send control byte IdleI2C(); // Wait for idle condition if (!SSPCON2bits.ACKSTAT) WriteI2C(data); } IdleI2C(); StopI2C(); IdleI2C(); return; } // If 24LC01B ACKs // Send data // Wait for idle condition // Send stop bit // Wait for idle condition
// Reads a byte of data from 24LC01B at the specified address unsigned char ByteRead(static unsigned char address) { StartI2C(); // Send start bit IdleI2C(); // Wait for idle condition WriteI2C(CONTROL); // Send control byte IdleI2C(); // Wait for idle condition if (!SSPCON2bits.ACKSTAT) // If the 24LC01B ACKs { WriteI2C(address); // Send address IdleI2C(); // Wait for idle condition if (!SSPCON2bits.ACKSTAT) // If the 24LC01B ACKs { RestartI2C(); // Send restart IdleI2C(); // Wait for idle condition WriteI2C(CONTROL+1); // Send control byte with R/W set IdleI2C(); // Wait for idle condition if (!SSPCON2bits.ACKSTAT) // If the 24LC01B ACKs { getcI2C(); // Read a byte of data from 24LC01B IdleI2C(); // Wait for idle condition NotAckI2C(); // Send a NACK to 24LC01B IdleI2C(); // Wait for idle condition StopI2C(); // Send stop bit IdleI2C(); // Wait for idle condition } } } return(SSPBUF); }
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PIC17C7XX
EXAMPLE 15-2: INTERFACING TO A 24LC01B SERIAL EEPROM (USING MPLAB C17)
void ACKPoll(void) { StartI2C(); // Send start bit IdleI2C(); // Wait for idle condition WriteI2C(CONTROL); // Send control byte IdleI2C(); // Wait for idle condition // Poll the ACK bit coming from the 24LC01B // Loop as long as the 24LC01B NACKs while (SSPCON2bits.ACKSTAT) { RestartI2C(); // Send a restart bit IdleI2C(); // Wait for idle condition WriteI2C(CONTROL); // Send control byte IdleI2C(); // Wait for idle condition } IdleI2C(); // Wait for idle condition StopI2C(); // Send stop bit IdleI2C(); // Wait for idle condition return; }
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PIC17C7XX
16.0 ANALOG-TO-DIGITAL CONVERTER (A/D) MODULE
The A/D converter has a unique feature of being able to operate while the device is in SLEEP mode. To operate in SLEEP, the A/D clock must be derived from the A/D's internal RC oscillator. The A/D module has four registers. These registers are: * * * * A/D Result High Register (ADRESH) A/D Result Low Register (ADRESL) A/D Control Register0 (ADCON0) A/D Control Register1 (ADCON1)
The analog-to-digital (A/D) converter module has twelve analog inputs for the PIC17C75X devices and sixteen for the PIC17C76X devices. The analog input charges a sample and hold capacitor. The output of the sample and hold capacitor is the input into the converter. The converter then generates a digital result of this analog level via successive approximation. This A/D conversion of the analog input signal, results in a corresponding 10-bit digital number. The analog reference voltages (positive and negative supply) are software selectable to either the device's supply voltages (AVDD, AVss), or the voltage level on the RG3/AN0/VREF+ and RG2/AN1/VREF- pins.
The ADCON0 register, shown in Register 16-1, controls the operation of the A/D module. The ADCON1 register, shown in Register 16-2, configures the functions of the port pins. The port pins can be configured as analog inputs (RG3 and RG2 can also be the voltage references), or as digital I/O.
REGISTER 16-1: ADCON0 REGISTER (ADDRESS: 14h, BANK 5)
R/W-0 CHS3 bit 7 bit 7-4 CHS3:CHS0: Analog Channel Select bits 0000 = channel 0, (AN0) 0001 = channel 1, (AN1) 0010 = channel 2, (AN2) 0011 = channel 3, (AN3) 0100 = channel 4, (AN4) 0101 = channel 5, (AN5) 0110 = channel 6, (AN6) 0111 = channel 7, (AN7) 1000 = channel 8, (AN8) 1001 = channel 9, (AN9) 1010 = channel 10, (AN10) 1011 = channel 11, (AN11) 1100 = channel 12, (AN12) (PIC17C76X only) 1101 = channel 13, (AN13) (PIC17C76X only) 1110 = channel 14, (AN14) (PIC17C76X only) 1111 = channel 15, (AN15) (PIC17C76X only) 11xx = RESERVED, do not select (PIC17C75X only) Unimplemented: Read as '0' GO/DONE: A/D Conversion Status bit If ADON = 1: 1 = A/D conversion in progress (setting this bit starts the A/D conversion, which is automatically cleared by hardware when the A/D conversion is complete) 0 = A/D conversion not in progress bit 1 bit 0 Unimplemented: Read as '0' ADON: A/D On bit 1 = A/D converter module is operating 0 = A/D converter module is shut-off and consumes no operating current Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown R/W-0 CHS2 R/W-0 CHS1 R/W-0 CHS0 U-0 -- R/W-0 GO/DONE U-0 -- R/W-0 ADON bit 0
bit 3 bit 2
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REGISTER 16-2: ADCON1 REGISTER (ADDRESS 15h, BANK 5)
R/W-0 ADCS1 bit 7 bit 7-6 ADCS1:ADCS0: A/D Conversion Clock Select bits 00 = FOSC/8 01 = FOSC/32 10 = FOSC/64 11 = FRC (clock derived from an internal RC oscillator) ADFM: A/D Result Format Select 1 = Right justified. 6 Most Significant bits of ADRESH are read as '0'. 0 = Left justified. 6 Least Significant bits of ADRESL are read as '0'. Unimplemented: Read as '0' PCFG3:PCFG1: A/D Port Configuration Control bits PCFG0: A/D Voltage Reference Select bit 1 = A/D reference is the VREF+ and VREF- pins 0 = A/D reference is AVDD and AVSS Note: When this bit is set, ensure that the A/D voltage reference specifications are met. R/W-0 ADCS0 R/W-0 ADFM U-0 -- R/W-0 PCFG3 R/W-0 PCFG2 R/W-0 PCFG1 R/W-0 PCFG0 bit 0
bit 5
bit 4 bit 3-1 bit 0
PCFG3:PCFG0
AN15 A D D D D D D D
AN14 AN13 AN12 AN11 A A D D D D D D A A A D D D D D A A A A D D D D A A A A A D D D
AN10 A A A A A A D D
AN9 AN8 AN7 A A A A A A A D A A A A A A A D A D D D D D D D
AN6 A A D D D D D D
AN5 AN4 A A A D D D D D A A A A D D D D
AN3 A A A A A D D D
AN2 A A A A A A D D
AN1 A A A A A A A D
AN0 A A A A A A A D
000x 001x 010x 011x 100x 101x 110x 111x
A = Analog input
D = Digital I/O
Legend: R = Readable bit - n = Value at POR Reset W = Writable bit '1' = Bit is set U = Unimplemented bit, read as `0' '0' = Bit is cleared x = Bit is unknown
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PIC17C7XX
The ADRESH:ADRESL registers contain the 10-bit result of the A/D conversion. When the A/D conversion is complete, the result is loaded into this A/D result register pair, the GO/DONE bit (ADCON0<2>) is cleared and A/D interrupt flag bit, ADIF is set. The block diagrams of the A/D module are shown in Figure 16-1. After the A/D module has been configured as desired, the selected channel must be acquired before the conversion is started. The analog input channels must have their corresponding DDR bits selected as inputs. To determine sample time, see Section 16.1. After this acquisition time has elapsed, the A/D conversion can be started. The following steps should be followed for doing an A/D conversion: 1. Configure the A/D module: a) Configure analog pins/voltage reference/ and digital I/O (ADCON1) b) Select A/D input channel (ADCON0) c) Select A/D conversion clock (ADCON0) d) Turn on A/D module (ADCON0) 2. Configure A/D interrupt (if desired): a) Clear ADIF bit b) Set ADIE bit c) Clear GLINTD bit Wait the required acquisition time. Start conversion: a) Set GO/DONE bit (ADCON0) Wait for A/D conversion to complete, by either: a) Polling for the GO/DONE bit to be cleared OR 6. 7. b) Waiting for the A/D interrupt Read A/D Result register pair (ADRESH:ADRESL), clear bit ADIF, if required. For next conversion, go to step 1 or step 2, as required. The A/D conversion time per bit is defined as TAD. A minimum wait of 2TAD is required before next acquisition starts.
3. 4. 5.
FIGURE 16-1:
A/D BLOCK DIAGRAM
CHS3:CHS0
1011 1011 1011 1011 1011
AN15(1) AN14(1) AN13(1) AN12(1) AN11
1010 1001
AN10 AN9
1000 0111
AN8 AN7
0110 0101
AN6 AN5
VIN (Input Voltage)
0100 0011
AN4 AN3 AN2
A/D Converter
0010 0001
AN1/VREFPCFG0 VREF(Reference Voltage) VREF+ AVDD AVSS
0000
AN0/VREF+
Note 1: These channels are only available on PIC16C76X devices.
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PIC17C7XX
Figure 16-2 shows the conversion sequence and the terms that are used. Acquisition time is the time that the A/D module's holding capacitor is connected to the external voltage level. Then, there is the conversion time of 12 TAD, which is started when the GO bit is set. The sum of these two times is the sampling time. There is a minimum acquisition time to ensure that the holding capacitor is charged to a level that will give the desired accuracy for the A/D conversion.
FIGURE 16-2:
A/D CONVERSION SEQUENCE
A/D Sample Time
Acquisition Time
A/D Conversion Time
A/D conversion complete, result is loaded in ADRES register. Holding capacitor begins acquiring voltage level on selected channel, ADIF bit is set.
When A/D conversion is started (setting the GO bit).
When A/D holding capacitor starts to charge. After A/D conversion, or when new A/D channel is selected.
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PIC17C7XX
16.1 A/D Acquisition Requirements
For the A/D converter to meet its specified accuracy, the charge holding capacitor (CHOLD) must be allowed to fully charge to the input channel voltage level. The analog input model is shown in Figure 16-3. The source impedance (RS) and the internal sampling switch (RSS) impedance directly affect the time required to charge the capacitor CHOLD. The sampling switch (RSS) impedance varies over the device voltage (VDD), Figure 16-3. The maximum recommended impedance for analog sources is 10 k. As the impedance is decreased, the acquisition time may be decreased. After the analog input channel is selected (changed) this 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 (1024 steps for the A/D). The 1/2 LSb error is the maximum error allowed for the A/D to meet its specified resolution. Example 16-1 shows the calculation of the minimum required acquisition time (TACQ). This is based on the following application system assumptions. CHOLD Rs Conversion Error VDD Temperature VHOLD = = = = = 120 pF 10 k 1/2 LSb 5V Rss = 7 k (see graph in Figure 16-3) 50C (system max.) 0V @ time = 0
EQUATION 16-1:
TACQ =
ACQUISITION TIME
Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient
=
TAMP + TC + TCOFF
EQUATION 16-2:
VHOLD or TC = =
A/D MINIMUM CHARGING TIME
(VREF - (VREF/2048)) * (1 - e(-Tc/CHOLD(RIC + RSS + RS))) -(120 pF)(1 k + RSS + RS) ln(1/2047)
EXAMPLE 16-1:
TACQ =
TACQ = TC =
CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME
TAMP + TC + TCOFF
2 s + Tc + [(Temp - 25C)(0.05 s/C)] -CHOLD (RIC + RSS + RS) ln(1/2047) -120 pF (1 k + 7 k + 10 k) ln(0.0004885) -120 pF (18 k) ln(0.0004885) -2.16 s (-7.6241) 16.47 s 2 s + 16.47 s + [(50xC - 25C)(0.05 s/C)] 18.447 s + 1.25 s 19.72 s
Temperature coefficient is only required for temperatures > 25C.
TACQ =
Note 1: The reference voltage (VREF) has no effect on the equation since it cancels itself out. 2: The charge holding capacitor (CHOLD) 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. 4: After a conversion has completed, a 2.0 TAD delay must complete before acquisition can begin again. During this time, the holding capacitor is not connected to the selected A/D input channel.
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PIC17C7XX
FIGURE 16-3: ANALOG INPUT MODEL
VDD VT = 0.6V RIC 1k Sampling Switch SS RSS CHOLD = DAC capacitance = 120 pF VSS Legend CPIN = input capacitance = threshold voltage VT I leakage = leakage current at the pin due to various junctions RIC SS CHOLD = interconnect resistance = sampling switch = sample/hold capacitance (from DAC)
RS
ANx
VA
CPIN 5 pF
VT = 0.6V
I leakage 500 nA
6V 5V VDD 4V 3V 2V
5 6 7 8 9 10 11 Sampling Switch ( k )
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PIC17C7XX
16.2 Selecting the A/D Conversion Clock
For correct A/D conversions, the A/D conversion clock (TAD) must be selected to ensure a minimum TAD time of 1.6 s. Table 16-1 and Table 16-2 show the resultant TAD times derived from the device operating frequencies and the A/D clock source selected. These times are for standard voltage range devices.
The A/D conversion time per bit is defined as TAD. The A/D conversion requires a minimum 12TAD per 10-bit conversion. The source of the A/D conversion clock is software selected. The four possible options for TAD are: * * * * 8TOSC 32TOSC 64TOSC Internal RC oscillator
TABLE 16-1:
TAD vs. DEVICE OPERATING FREQUENCIES (STANDARD DEVICES (C))
AD Clock Source (TAD) Max FOSC (MHz) 5 20 33 --
Operation 8TOSC 32TOSC 64TOSC RC Note:
ADCS1:ADCS0 00 01 10 11
When the device frequency is greater than 1 MHz, the RC A/D conversion clock source is only recommended for SLEEP operation.
TABLE 16-2:
TAD vs. DEVICE OPERATING FREQUENCIES (EXTENDED VOLTAGE DEVICES (LC))
AD Clock Source (TAD) Max FOSC (MHz) 2.67 10.67 21.33 --
Operation 8TOSC 32TOSC 64TOSC RC Note:
ADCS1:ADCS0 00 01 10 11
When the device frequency is greater than 1 MHz, the RC A/D conversion clock source is only recommended for SLEEP operation.
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16.3 Configuring Analog Port Pins 16.4 A/D Conversions
The ADCON1, and DDR registers control the operation of the A/D port pins. The port pins that are desired as analog inputs must have their corresponding DDR bits set (input). If the DDR bit is cleared (output), the digital output level (VOH or VOL) will be converted. The A/D operation is independent of the state of the CHS2:CHS0 bits and the DDR bits. Note 1: When reading the port register, any pin configured as an analog input channel will read as cleared (a low level). Pins configured as digital inputs, will convert an analog input. Analog levels on a digitally configured input will not affect the conversion accuracy. 2: Analog levels on any pin that is defined as a digital input (including the AN15:AN0 pins), may cause the input buffer to consume current that is out of the devices specification. Example 16-2 shows how to perform an A/D conversion. The PORTF and lower four PORTG pins are configured as analog inputs. The analog references (VREF+ and VREF-) are the device AVDD and AVSS. The A/D interrupt is enabled, and the A/D conversion clock is FRC. The conversion is performed on the RG3/AN0 pin (channel 0). Note: The GO/DONE bit should NOT be set in the same instruction that turns on the A/D.
Clearing the GO/DONE bit during a conversion will abort the current conversion. The A/D result register pair will NOT be updated with the partially completed A/ D conversion sample. That is, the ADRESH:ADRESL registers will continue to contain the value of the last completed conversion (or the last value written to the ADRESH:ADRESL registers). After the A/D conversion is aborted, a 2TAD wait is required before the next acquisition is started. After this 2TAD wait, acquisition on the selected channel is automatically started. In Figure 16-4, after the GO bit is set, the first time segment has a minimum of TCY and a maximum of TAD.
EXAMPLE 16-2:
MOVLB CLRF MOVLW MOVWF MOVLB BCF BSF BSF BCF ; ; ; ;
A/D CONVERSION
; ; ; ; ; ; ; ; ; Bank 5 Configure A/D inputs, All analog, TAD = Fosc/8, left just. A/D is on, Channel 0 is selected Bank 4 Clear A/D interrupt flag bit Enable A/D interrupts Enable peripheral interrupts Enable all interrupts
5 ADCON1, F 0x01 ADCON0 4 PIR2, ADIF PIE2, ADIE INTSTA, PEIE CPUSTA, GLINTD
Ensure that the required sampling time for the selected input channel has elapsed. Then the conversion may be started. MOVLB BSF : : 5 ADCON0, GO ; Bank 5 ; Start A/D Conversion ; The ADIF bit will be set and the GO/DONE bit ; is cleared upon completion of the A/D Conversion
FIGURE 16-4:
A/D CONVERSION TAD CYCLES
TCY to TAD TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD9 TAD10 TAD11 b1 b3 b0 b4 b2 b5 b7 b6 b8 b9 Conversion starts. Holding capacitor is disconnected from analog input (typically 100 ns). Set GO bit Next Q4: ADRES is loaded, GO bit is cleared, ADIF bit is set, holding capacitor is connected to analog input.
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PIC17C7XX
FIGURE 16-5: FLOW CHART OF A/D OPERATION
ADON = 0
Yes ADON = 0?
No Acquire Selected Channel
Yes GO = 0?
No
A/D Clock = RC? No
Yes
Start of A/D Conversion Delayed 1 Instruction Cycle
Yes SLEEP Instruction? No
Finish Conversion GO = 0, ADIF = 1
Device in SLEEP? No
Yes
Abort Conversion GO = 0, ADIF = 0
Finish Conversion GO = 0, ADIF = 1
Wake-up Yes From SLEEP?
Wait 2TAD
No
Finish Conversion GO = 0, ADIF = 1
SLEEP Power-down A/D
Wait 2TAD
Stay in SLEEP Power-down A/D
Wait 2TAD
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PIC17C7XX
16.4.1 A/D RESULT REGISTERS
The ADRESH:ADRESL register pair is the location where the 10-bit A/D result is loaded at the completion of the A/D conversion. This register pair is 16-bits wide. The A/D module gives the flexibility to left or right justify the 10-bit result in the 16-bit result register. The A/D Format Select bit (ADFM) controls this justification. Figure 16-6 shows the operation of the A/D result justification. The extra bits are loaded with '0's'. When an A/ D result will not overwrite these locations (A/D disable), these registers may be used as two general purpose 8bit registers. SLEEP. If the A/D interrupt is not enabled, the A/D module will then be turned off, although the ADON bit will remain set. When the A/D clock source is another clock option (not RC), a SLEEP instruction will cause the present conversion to be aborted and the A/D module to be turned off, though the ADON bit will remain set. Turning off the A/D places the A/D module in its lowest current consumption state. Note: For the A/D module to operate in SLEEP, the A/D clock source must be set to RC (ADCS1:ADCS0 = 11). To allow the conversion to occur during SLEEP, ensure the SLEEP instruction immediately follows the instruction that sets the GO/DONE bit.
16.5
A/D Operation During SLEEP
The A/D module can operate during SLEEP mode. This requires that the A/D clock source be set to RC (ADCS1:ADCS0 = 11). When the RC clock source is selected, the A/D module waits one instruction cycle before starting the conversion. This allows the SLEEP instruction to be executed, which eliminates all digital switching noise from the conversion. When the conversion is completed, the GO/DONE bit will be cleared, and the result loaded into the ADRES register. If the A/ D interrupt is enabled, the device will wake-up from
16.6
Effects of a RESET
A device RESET forces all registers to their RESET state. This forces the A/D module to be turned off, and any conversion is aborted. The value that is in the ADRESH:ADRESL registers is not modified for a Power-on Reset. The ADRESH:ADRESL registers will contain unknown data after a Power-on Reset.
FIGURE 16-6:
A/D RESULT JUSTIFICATION
10-Bit Result ADFM = 1 ADFM = 0
7 0000 00
2107
0
7
0765
0 0000 00
RESULT
ADRESL 10-bits
RESULT
ADRESH 10-bits
ADRESH
ADRESL
Right Justified
Left Justified
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PIC17C7XX
16.7 A/D Accuracy/Error
In systems where the device frequency is low, use of the A/D RC clock is preferred. At moderate to high frequencies, TAD should be derived from the device oscillator. The absolute accuracy specified for the A/D converter includes the sum of all contributions for quantization error, integral error, differential error, full scale error, offset error, and monotonicity. It is defined as the maximum deviation from an actual transition versus an ideal transition for any code. The absolute error of the A/D converter is specified at < 1 LSb for VDD = VREF (over the device's specified operating range). However, the accuracy of the A/D converter will degrade as VREF diverges from VDD. For a given range of analog inputs, the output digital code will be the same. This is due to the quantization of the analog input to a digital code. Quantization error is typically 1/2 LSb and is inherent in the analog to digital conversion process. The only way to reduce quantization error is to increase the resolution of the A/D converter or oversample. Offset error measures the first actual transition of a code versus the first ideal transition of a code. Offset error shifts the entire transfer function. Offset error can be calibrated out of a system or introduced into a system through the interaction of the total leakage current and source impedance at the analog input. Gain error measures the maximum deviation of the last actual transition and the last ideal transition adjusted for offset error. This error appears as a change in slope of the transfer function. The difference in gain error to full scale error is that full scale does not take offset error into account. Gain error can be calibrated out in software. Linearity error refers to the uniformity of the code changes. Linearity errors cannot be calibrated out of the system. Integral non-linearity error measures the actual code transition versus the ideal code transition, adjusted by the gain error for each code. Differential non-linearity measures the maximum actual code width versus the ideal code width. This measure is unadjusted. The maximum pin leakage current is specified in the Device Data Sheet electrical specification (Table 20-2, parameter #D060). In systems where the device frequency is low, use of the A/D RC clock is preferred. At moderate to high frequencies, TAD should be derived from the device oscillator. TAD must not violate the minimum and should be minimized to reduce inaccuracies due to noise and sampling capacitor bleed off. In systems where the device will enter SLEEP mode after the start of the A/D conversion, the RC clock source selection is required. In this mode, the digital noise from the modules in SLEEP are stopped. This method gives high accuracy.
16.8
Connection Considerations
If the input voltage exceeds the rail values (VSS or VDD) by greater than 0.3V, then the accuracy of the conversion is out of specification. An external RC filter is sometimes added for antialiasing of the input signal. The R component should be selected to ensure that the total source impedance is kept under the 10 k recommended specification. Any external components connected (via hi-impedance) to an analog input pin (capacitor, zener diode, etc.) should have very little leakage current at the pin.
16.9
Transfer Function
The transfer function of the A/D converter is as follows: the first transition occurs when the analog input voltage (VAIN) equals Analog VREF / 1024 (Figure 16-7).
FIGURE 16-7:
A/D TRANSFER FUNCTION
3FFh Digital Code Output 3FEh
003h 002h 001h 000h 0.5 LSb 1.5 LSb 2.5 LSb 1 LSb 2 LSb 3 LSb
1022.5 LSb
Analog Input Voltage
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1023.5 LSb
1022 LSb
1023 LSb
PIC17C7XX
16.10 References
A good reference for understanding A/D converter is the "Analog-Digital Conversion Handbook" third edition, published by Prentice Hall (ISBN 0-13-03-2848-0).
TABLE 16-3:
Address
REGISTERS/BITS ASSOCIATED WITH A/D
Name Bit 7 -- PEIF SSPIF SSPIE Bit 6 -- T0CKIF BCLIF BCLIE Bit 5 STAKAV T0IF ADIF ADIE Bit 4 GLINTD INTF -- -- Bit 3 TO PEIE CA4IF CA4IE Bit 2 PD T0CKIE CA3IF CA3IE Bit 1 POR T0IE TX2IF TX2IE Bit 0 BOR INTE RC2IF RC2IE POR, BOR
--11 1100 0000 0000 000- 0010 000- 0000 1111 1111
MCLR, WDT
--11 qq11 0000 0000 000- 0010 000- 0000 1111 1111 0000 0000 1111 1111 uuuu 0000 0000 -0-0 000- 0000 uuuu uuuu uuuu uuuu
06h, unbanked CPUSTA 07h, unbanked INTSTA 10h, Bank 4 11h, Bank 4 10h, Bank 5 11h, Bank 5 12h, Bank 5 13h, Bank 5 14h, Bank 5 15h, Bank 5 16h, Bank 5 17h, Bank 5 Legend: Note: PIR2 PIE2 DDRF PORTF DDRG PORTG ADCON0 ADCON1 ADRESL ADRESH
Data Direction Register for PORTF RF7/ AN11 RF6/ AN10 RF5/ AN9 RF4/ AN8 RF3/ AN7 RF2/ AN6 RF1/ AN5 RF0/ AN4
0000 0000 1111 1111
Data Direction register for PORTG RG7/ RG6/ TX2/CK2 RX2/DT2 CHS3 ADCS1 CHS2 ADCS0 RG5/ PWM3 CHS1 ADFM RG4/ CAP3 CHS0 -- RG2/ RG3/ AN0/VREF+ AN1/VREF-- PCFG3 GO/DONE PCFG2 RG1/ AN2 -- PCFG1 RG0/ AN3 ADON PCFG0
xxxx 0000 0000 -0-0 000- 0000 xxxx xxxx xxxx xxxx
A/D Result Low Register A/D Result High Register
x = unknown, u = unchanged, - = unimplemented, read as '0'. Shaded cells are not used for A/D conversion.
Other (non power-up) RESETS include: external RESET through MCLR and Watchdog Timer Reset.
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PIC17C7XX
17.0 SPECIAL FEATURES OF THE CPU
The PIC17CXXX has a Watchdog Timer which can be shut-off only through EPROM bits. It runs off its own RC oscillator for added reliability. There are two timers that offer necessary delays on POR and BOR. One is the Oscillator Start-up Timer (OST), intended to keep the chip in RESET until the crystal oscillator is stable. The other is the Power-up Timer (PWRT), which provides a fixed delay of 96 ms (nominal) on power-up only, designed to keep the part in RESET while the power supply stabilizes. With these two timers on-chip, most applications need no external RESET circuitry. The SLEEP mode is designed to offer a very low current power-down mode. The user can wake from SLEEP through external RESET, Watchdog Timer Reset, or through an interrupt. Several oscillator options are also made available to allow the part to fit the application. The RC oscillator option saves system cost, while the LF crystal option saves power. Configuration bits are used to select various options. This configuration word has the format shown in Figure 17-1.
What sets a microcontroller apart from other processors are special circuits to deal with the needs of realtime applications. The PIC17CXXX family has a host of such features intended to maximize system reliability, minimize cost through elimination of external components, provide power saving operating modes and offer code protection. These are: * Oscillator Selection (Section 4.0) * RESET (Section 5.0) - Power-on Reset (POR) - Power-up Timer (PWRT) - Oscillator Start-up Timer (OST) - Brown-out Reset (BOR) * Interrupts (Section 6.0) * Watchdog Timer (WDT) * SLEEP mode * Code protection
REGISTER 17-1: CONFIGURATION WORDS
High (H) Table Read Addr. FE0Fh - FE08h U-x -- bit 15 Low (L) Table Read Addr. FE07h - FE00h U-x -- bit 15 bits 7H, 6L, 4L R/P-1 PM2 bit 8 bit 7 U-x -- bit 8 bit 7 R/P-1 PM1 U-x -- R/P-1 PM0 R/P-1 R/P-1 R/P-1 R/P-1 BODEN U-x -- U-x -- U-x -- U-x -- U-x -- U-x -- bit 0 R/P-1 bit 0
WDTPS1 WDTPS0 FOSC1 FOSC0
PM2, PM1, PM0: Processor Mode Select bits 111 = Microprocessor mode 110 = Microcontroller mode 101 = Extended Microcontroller mode 000 = Code Protected Microcontroller mode BODEN: Brown-out Detect Enable 1 = Brown-out Detect circuitry is enabled 0 = Brown-out Detect circuitry is disabled WDTPS1:WDTPS0: WDT Postscaler Select bits 11 = WDT enabled, postscaler = 1 10 = WDT enabled, postscaler = 256 01 = WDT enabled, postscaler = 64 00 = WDT disabled, 16-bit overflow timer FOSC1:FOSC0: Oscillator Select bits 11 = EC oscillator 10 = XT oscillator 01 = RC oscillator 00 = LF oscillator Reserved
bit 6H
bits 3L:2L
bits 1L:0L
Shaded bits (--)
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PIC17C7XX
17.1 Configuration Bits 17.2
17.2.1
Oscillator Configurations
OSCILLATOR TYPES
The PIC17CXXX has eight configuration locations (Table 17-1). These locations can be programmed (read as '0'), or left unprogrammed (read as '1') to select various device configurations. Any write to a configuration location, regardless of the data, will program that configuration bit. A TABLWT instruction and raising the MCLR/VPP pin to the programming voltage are both required to write to program memory locations. The configuration bits can be read by using the TABLRD instructions. Reading any configuration location between FE00h and FE07h will read the low byte of the configuration word (Figure 17-1) into the TABLATL register. The TABLATH register will be FFh. Reading a configuration location between FE08h and FE0Fh will read the high byte of the configuration word into the TABLATL register. The TABLATH register will be FFh. Addresses FE00h through FE0Fh are only in the program memory space for Microcontroller and Code Protected Microcontroller modes. A device programmer will be able to read the configuration word in any processor mode. See programming specifications for more detail.
The PIC17CXXX can be operated in four different oscillator modes. The user can program two configuration bits (FOSC1:FOSC0) to select one of these four modes: * * * * LF XT EC RC Low Power Crystal Crystal/Resonator External Clock Input Resistor/Capacitor
For information on the different oscillator types and how to use them, please refer to Section 4.0.
TABLE 17-1:
Bit
CONFIGURATION LOCATIONS
Address FE00h FE01h FE02h FE03h FE04h FE06h FE0Eh FE0Fh
FOSC0 FOSC1 WDTPS0 WDTPS1 PM0 PM1 BODEN PM2
Note:
When programming the desired configuration locations, they must be programmed in ascending order, starting with address FE00h.
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PIC17C7XX
17.3 Watchdog Timer (WDT)
17.3.2
The Watchdog Timer's function is to recover from software malfunction, or to reset the device while in SLEEP mode. The WDT uses an internal free running on-chip RC oscillator for its clock source. This does not require any external components. This RC oscillator is separate from the RC oscillator of the OSC1/CLKIN pin. That means that the WDT will run even if the clock on the OSC1/CLKIN and OSC2/CLKOUT pins has been stopped, for example, by execution of a SLEEP instruction. During normal operation, a WDT time-out generates a device RESET. The WDT can be permanently disabled by programming the configuration bits WDTPS1:WDTPS0 as '00' (Section 17.1). Under normal operation, the WDT must be cleared on a regular interval. This time must be less than the minimum WDT overflow time. Not clearing the WDT in this time frame will cause the WDT to overflow and reset the device.
CLEARING THE WDT AND POSTSCALER
The WDT and postscaler are cleared when: * * * * The device is in the RESET state A SLEEP instruction is executed A CLRWDT instruction is executed Wake-up from SLEEP by an interrupt
The WDT counter/postscaler will start counting on the first edge after the device exits the RESET state.
17.3.3
WDT PROGRAMMING CONSIDERATIONS
It should also be taken in account that under worst case conditions (VDD = Min., Temperature = Max., Max. WDT postscaler), it may take several seconds before a WDT time-out occurs. The WDT and postscaler become the Power-up Timer whenever the PWRT is invoked.
17.3.1
WDT PERIOD
The WDT has a nominal time-out period of 12 ms (with postscaler = 1). The time-out periods vary with temperature, VDD and process variations from part to part (see DC specs). If longer time-out periods are desired, configuration bits should be used to enable the WDT with a greater prescale. Thus, typical time-out periods up to 3.0 seconds can be realized. The CLRWDT and SLEEP instructions clear the WDT and its postscale setting and prevent it from timing out, thus generating a device RESET condition. The TO bit in the CPUSTA register will be cleared upon a WDT time-out.
17.3.4
WDT AS NORMAL TIMER
When the WDT is selected as a normal timer, the clock source is the device clock. Neither the WDT nor the postscaler are directly readable or writable. The overflow time is 65536 TOSC cycles. On overflow, the TO bit is cleared (device is not RESET). The CLRWDT instruction can be used to set the TO bit. This allows the WDT to be a simple overflow timer. The simple timer does not increment when in SLEEP.
FIGURE 17-1:
WATCHDOG TIMER BLOCK DIAGRAM
On-chip RC Oscillator(1)
WDT
Postscaler
4 - to - 1 MUX WDT Enable Note 1: This oscillator is separate from the external RC oscillator on the OSC1 pin.
WDTPS1:WDTPS0
WDT Overflow
TABLE 17-2:
Address --
REGISTERS/BITS ASSOCIATED WITH THE WATCHDOG TIMER
Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR (Note 1) POR BOR
--11 11qq
MCLR, WDT (Note 1)
--11 qquu
Config
See Figure 17-1 for location of WDTPSx bits in Configuration Word. -- -- STKAV GLINTD TO PD
06h, Unbanked CPUSTA
Legend: - = unimplemented, read as '0', q = value depends on condition. Shaded cells are not used by the WDT. Note 1: This value will be as the device was programmed, or if unprogrammed, will read as all '1's.
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PIC17C7XX
17.4 Power-down Mode (SLEEP)
The Power-down mode is entered by executing a SLEEP instruction. This clears the Watchdog Timer and postscaler (if enabled). The PD bit is cleared and the TO bit is set (in the CPUSTA register). In SLEEP mode, the oscillator driver is turned off. The I/O ports maintain their status (driving high,low, or hi-impedance input). The MCLR/VPP pin must be at a logic high level (VIHMC). A WDT time-out RESET does not drive the MCLR/VPP pin low. Any RESET event will cause a device RESET. Any interrupt event is considered a continuation of program execution. The TO and PD bits in the CPUSTA register can be used to determine the cause of a device RESET. The PD bit, which is set on power-up, is cleared when SLEEP is invoked. The TO bit is cleared if WDT time-out occurred (and caused a RESET). When the SLEEP instruction is being executed, the next instruction (PC + 1) is pre-fetched. For the device to wake-up through an interrupt event, the corresponding interrupt enable bit must be set (enabled). Wake-up is regardless of the state of the GLINTD bit. If the GLINTD bit is set (disabled), the device continues execution at the instruction after the SLEEP instruction. If the GLINTD bit is clear (enabled), the device executes the instruction after the SLEEP instruction and then branches to the interrupt vector address. In cases where the execution of the instruction following SLEEP is not desirable, the user should have a NOP after the SLEEP instruction. Note: If the global interrupt is disabled (GLINTD is set), but any interrupt source has both its interrupt enable bit and the corresponding interrupt flag bit set, the device will immediately wake-up from SLEEP. The TO bit is set and the PD bit is cleared.
17.4.1
WAKE-UP FROM SLEEP
The device can wake-up from SLEEP through one of the following events: * * * * * Power-on Reset Brown-out Reset External RESET input on MCLR/VPP pin WDT Reset (if WDT was enabled) Interrupt from RA0/INT pin, RB port change, T0CKI interrupt, or some peripheral interrupts
The following peripheral interrupts can wake the device from SLEEP: * * * * * * Capture interrupts USART synchronous slave transmit interrupts USART synchronous slave receive interrupts A/D conversion complete SPI slave transmit/receive complete I2C slave receive
The WDT is cleared when the device wakes from SLEEP, regardless of the source of wake-up.
17.4.1.1
Wake-up Delay
Other peripherals cannot generate interrupts since during SLEEP, no on-chip Q clocks are present.
When the oscillator type is configured in XT or LF mode, the Oscillator Start-up Timer (OST) is activated on wake-up. The OST will keep the device in RESET for 1024TOSC. This needs to be taken into account when considering the interrupt response time when coming out of SLEEP.
FIGURE 17-2:
Q1 OSC1
WAKE-UP FROM SLEEP THROUGH INTERRUPT
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
TOST(2) CLKOUT(4) INT (RA0/INT pin) INTF Flag GLINTD bit INSTRUCTION FLOW PC Instruction Fetched Instruction Executed
PC PC+1
'0' or '1' Interrupt Latency(2) Processor in SLEEP
PC+2 0004h 0005h
Inst (PC) = SLEEP Inst (PC-1)
Inst (PC+1) SLEEP
Inst (PC+2) Inst (PC+1) Dummy Cycle
Note 1: XT or LF oscillator mode assumed. 2: TOST = 1024TOSC (drawing not to scale). This delay will not be there for RC osc mode. 3: When GLINTD = 0, processor jumps to interrupt routine after wake-up. If GLINTD = 1, execution will continue in line. 4: CLKOUT is not available in these osc modes, but shown here for timing reference.
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PIC17C7XX
17.4.2 MINIMIZING CURRENT CONSUMPTION
17.5
Code Protection
To minimize current consumption, all I/O pins should be either at VDD, or VSS, with no external circuitry drawing current from the I/O pin. I/O pins that are hi-impedance inputs should be pulled high or low externally to avoid switching currents caused by floating inputs. The T0CKI input should be at VDD or VSS. The contributions from on-chip pull-ups on PORTB should also be considered and disabled, when possible.
The code in the program memory can be protected by selecting the microcontroller in Code Protected mode (PM2:PM0 = '000'). In this mode, instructions that are in the on-chip program memory space, can continue to read or write the program memory. An instruction that is executed outside of the internal program memory range will be inhibited from writing to, or reading from, program memory. Note: Microchip does not recommend code protecting windowed devices.
If the code protection bit(s) have not been programmed, the on-chip program memory can be read out for verification purposes.
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PIC17C7XX
17.6 In-Circuit Serial Programming
The PIC17C7XX group of the high-end family (PIC17CXXX) has an added feature that allows serial programming while in the end application circuit. This is simply done with two lines for clock and data and three other lines for power, ground, and the programming voltage. This allows customers to manufacture boards with unprogrammed devices and then program the microcontroller just before shipping the product. This also allows the most recent firmware, or a custom firmware to be programmed. Devices may be serialized to make the product unique; "special" variants of the product may be offered and code updates are possible. This allows for increased design flexibility. To place the device into the Serial Programming Test mode, two pins will need to be placed at VIHH. These are the TEST pin and the MCLR/VPP pin. Also, a sequence of events must occur as follows: 1. 2. The TEST pin is placed at VIHH. The MCLR/VPP pin is placed at VIHH. For complete details of serial programming, please refer to the PIC17C7XX Programming Specification. (Contact your local Microchip Technology Sales Office for availability.)
FIGURE 17-3:
TYPICAL IN-CIRCUIT SERIAL PROGRAMMING CONNECTION
To Normal Connections PIC17C7XX VDD VSS MCLR/VPP TEST RA1/T0CKI RA4/RX1/DT1 RA5/TX1/CK1
External Connector Signals +5V 0V VPP TEST CNTL Dev. CLK Data I/O Data CLK
There is a setup time between step 1 and step 2 that must be met. After this sequence, the Program Counter is pointing to program memory address 0xFF60. This location is in the Boot ROM. The code initializes the USART/SCI so that it can receive commands. For this, the device must be clocked. The device clock source in this mode is the RA1/T0CKI pin. After delaying to allow the USART/SCI to initialize, commands can be received. The flow is shown in these 3 steps: 1. 2. 3. The device clock source starts. Wait 80 device clocks for Boot ROM code to configure the USART/SCI. Commands may now be sent.
VDD To Normal Connections
TABLE 17-3:
ICSP INTERFACE PINS
During Programming
Name RA4/RX1/DT1 RA5/TX1/CK1 RA1/T0CKI TEST MCLR/VPP VDD VSS
Function DT CK OSCI TEST MCLR/VPP VDD VSS
Type I/O I I I P P P
Description Serial Data Serial Clock Device Clock Source Test mode selection control input, force to VIHH Master Clear Reset and Device Programming Voltage Positive supply for logic and I/O pins Ground reference for logic and I/O pins
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PIC17C7XX
18.0 INSTRUCTION SET SUMMARY
TABLE 18-1:
Field
f p i t
The PIC17CXXX instruction set consists of 58 instructions. Each instruction is a 16-bit word divided into an OPCODE and one or more operands. The opcode specifies the instruction type, while the operand(s) further specify the operation of the instruction. The PIC17CXXX instruction set can be grouped into three types: * byte-oriented * bit-oriented * literal and control operations These formats are shown in Figure 18-1. Table 18-1 shows the field descriptions for the opcodes. These descriptions are useful for understanding the opcodes in Table 18-2 and in each specific instruction descriptions. For byte-oriented instructions, 'f' represents a file register designator and 'd' represents a destination designator. The file register designator specifies which file register is to be used by the instruction. The destination designator specifies where the result of the operation is to be placed. If 'd' = '0', the result is placed in the WREG register. If 'd' = '1', the result is placed in the file register specified by the instruction. For bit-oriented instructions, 'b' represents a bit field designator which selects the number of the bit affected by the operation, while 'f' represents the number of the file in which the bit is located. For literal and control operations, 'k' represents an 8or 13-bit constant or literal value. The instruction set is highly orthogonal and is grouped into: * byte-oriented operations * bit-oriented operations * literal and control operations All instructions are executed within one single instruction cycle, unless: * a conditional test is true * the program counter is changed as a result of an instruction * a table read or a table write instruction is executed (in this case, the execution takes two instruction cycles with the second cycle executed as a NOP) One instruction cycle consists of four oscillator periods. Thus, for an oscillator frequency of 25 MHz, the normal instruction execution time is 160 ns. If a conditional test is true or the program counter is changed as a result of an instruction, the instruction execution time is 320 ns.
OPCODE FIELD DESCRIPTIONS
Description
Register file address (00h to FFh) Peripheral register file address (00h to 1Fh) Table pointer control i = '0' (do not change) i = '1' (increment after instruction execution) Table byte select t = '0' (perform operation on lower byte) t = '1' (perform operation on upper byte literal field, constant data) Working register (accumulator) Bit address within an 8-bit file register Literal field, constant data or label 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. Destination select 0 = store result in WREG 1 = store result in file register f Default is d = '1' Unused, encoded as '0' Destination select 0 = store result in file register f and in the WREG 1 = store result in file register f Default is s = '1'
WREG b k x
d
u s
label Label name C,DC, ALU status bits Carry, Digit Carry, Zero, Overflow Z,OV GLINTD Global Interrupt Disable bit (CPUSTA<4>) TBLPTR Table Pointer (16-bit) TBLAT Table Latch (16-bit) consists of high byte (TBLATH) and low byte (TBLATL) TBLATL Table Latch low byte TBLATH Table Latch high byte TOS PC BSR WDT TO PD dest
Top-of-Stack Program Counter Bank Select Register Watchdog Timer Counter Time-out bit Power-down bit Destination either the WREG register or the specified register file location Options Contents Assigned to Register bit field
[]
() <>
In the set of italics User defined term (font is courier)
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DS30289B-page 197
PIC17C7XX
Table 18-2 lists the instructions recognized by the MPASM assembler. Note 1: Any unused opcode is Reserved. Use of any reserved opcode may cause unexpected operation. All instruction examples use the following format to represent a hexadecimal number: 0xhh where h signifies a hexadecimal digit. To represent a binary number: 0000 0100b where b signifies a binary string.
18.1
Special Function Registers as Source/Destination
The PIC17C7XX's orthogonal instruction set allows read and write of all file registers, including special function registers. There are some special situations the user should be aware of:
18.1.1
ALUSTA AS DESTINATION
If an instruction writes to ALUSTA, the Z, C, DC and OV bits may be set or cleared as a result of the instruction and overwrite the original data bits written. For example, executing CLRF ALUSTA will clear register ALUSTA and then set the Z bit leaving 0000 0100b in the register.
FIGURE 18-1:
GENERAL FORMAT FOR INSTRUCTIONS
9 8 d 7 f (FILE #) 0
18.1.2
PCL AS SOURCE OR DESTINATION
Byte-oriented file register operations 15 OPCODE
Read, write or read-modify-write on PCL may have the following results: Read PC: Write PCL: Read-Modify-Write: PCH PCLATH; PCL dest PCLATH PCH; 8-bit destination value PCL PCL ALU operand PCLATH PCH; 8-bit result PCL
d = 0 for destination WREG d = 1 for destination f f = 8-bit file register address Byte to Byte move operations 15 13 12 87 OPCODE p (FILE #) 0 f (FILE #)
p = peripheral register file address f = 8-bit file register address Bit-oriented file register operations 15 OPCODE 11 10 87 b (BIT #) 0 f (FILE #)
Where PCH = program counter high byte (not an addressable register), PCLATH = Program counter high holding latch, dest = destination, WREG or f.
18.1.3
BIT MANIPULATION
b = 3-bit address f = 8-bit file register address Literal and control operations 15 OPCODE k = 8-bit immediate value CALL and GOTO operations 15 13 12 OPCODE k = 13-bit immediate value 0 k (literal) 8 7 k (literal) 0
All bit manipulation instructions are done by first reading the entire register, operating on the selected bit and writing the result back (read-modify-write (R-M-W)). The user should keep this in mind when operating on some special function registers, such as ports. Note: Status bits that are manipulated by the device (including the interrupt flag bits) are set or cleared in the Q1 cycle. So, there is no issue on doing R-M-W instructions on registers which contain these bits
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PIC17C7XX
18.2 Q Cycle Activity
Each instruction cycle (TCY) is comprised of four Q cycles (Q1-Q4). The Q cycle is the same as the device oscillator cycle (TOSC). The Q cycles provide the timing/ designation for the Decode, Read, Process Data, Write, etc., of each instruction cycle. The following diagram shows the relationship of the Q cycles to the instruction cycle. The four Q cycles that make up an instruction cycle (TCY) can be generalized as: Q1: Instruction Decode Cycle or forced No operation Q2: Instruction Read Cycle or No operation Q3: Process the Data Q4: Instruction Write Cycle or No operation Each instruction will show the detailed Q cycle operation for the instruction.
FIGURE 18-2:
Q CYCLE ACTIVITY
Q1 TOSC Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
TCY1
TCY2
TCY3
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PIC17C7XX
TABLE 18-2:
Mnemonic, Operands
PIC17CXXX INSTRUCTION SET
16-bit Opcode Description Cycles MSb LSb Status Affected Notes
BYTE-ORIENTED FILE REGISTER OPERATIONS ADDWF f,d ADD WREG to f ADD WREG and Carry bit to f AND WREG with f Clear f, or Clear f and Clear WREG Complement f Compare f with WREG, skip if f = WREG Compare f with WREG, skip if f > WREG Compare f with WREG, skip if f < WREG Decimal Adjust WREG Register Decrement f Decrement f, skip if 0 Decrement f, skip if not 0 Increment f Increment f, skip if 0 Increment f, skip if not 0 Inclusive OR WREG with f Move f to p Move p to f Move WREG to f Multiply WREG with f Negate WREG No Operation Rotate left f through Carry Rotate left f (no carry) Rotate right f through Carry Rotate right f (no carry) Set f Subtract WREG from f Subtract WREG from f with Borrow Swap f Table Read Table Write Table Latch Read
Table Latch Write
1 1 1 1 1 1 (2) 1 (2) 1 (2) 1 1 1 (2) 1 (2) 1 1 (2) 1 (2) 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 (3) 2 1
1
0000 0001 0000 0010 0001 0011 0011 0011 0010 0000 0001 0010 0001 0001 0010 0000 011p 010p 0000 0011 0010 0000 0001 0010 0001 0010 0010 0000 0000 0001 1010 1010 1010 1010
111d ffff ffff 000d ffff ffff 101d ffff ffff 100s ffff ffff 001d ffff ffff 0001 ffff ffff 0010 ffff ffff 0000 ffff ffff 111s ffff ffff 011d ffff ffff 011d ffff ffff 011d ffff ffff 010d ffff ffff 111d ffff ffff 010d ffff ffff 100d ffff ffff pppp ffff ffff pppp ffff ffff 0001 ffff ffff 0100 ffff ffff 110s ffff ffff 0000 0000 0000 101d ffff ffff 001d ffff ffff 100d ffff ffff 000d ffff ffff 101s ffff ffff 010d ffff ffff 001d ffff ffff 110d ffff ffff 10ti ffff ffff 11ti ffff ffff 00tx ffff ffff 01tx ffff ffff
OV,C,DC,Z OV,C,DC,Z Z None Z None None None C OV,C,DC,Z None None OV,C,DC,Z None None Z None Z None None OV,C,DC,Z None C None C None None OV,C,DC,Z OV,C,DC,Z None None None None
None
ADDWFC f,d ANDWF CLRF COMF CPFSEQ CPFSGT CPFSLT DAW DECF DECFSZ DCFSNZ INCF INCFSZ INFSNZ IORWF MOVFP MOVPF MOVWF MULWF NEGW NOP RLCF RLNCF RRCF RRNCF SETF SUBWF f,d f,s f,d f f f f,s f,d f,d f,d f,d f,d f,d f,d f,p p,f f f f,s -- f,d f,d f,d f,d f,s f,d
3
6,8 2,6,8 2,6,8 3
6,8 6,8
6,8 6,8
1,3
3 1 1
SUBWFB f,d SWAPF TABLRD TABLWT TLRD TLWT Legend: Note 1: 2: 3: 4: 5: 6: 7: 8: f,d t,i,f t,i,f t,f t,f
7 5
Refer to Table 18-1 for opcode field descriptions. 2's Complement method. Unsigned arithmetic. If s = '1', only the file is affected: If s = '0', both the WREG register and the file are affected; If only the Working register (WREG) is required to be affected, then f = WREG must be specified. During an LCALL, the contents of PCLATH are loaded into the MSB of the PC and kkkk kkkk is loaded into the LSB of the PC (PCL). Multiple cycle instruction for EPROM programming when table pointer selects internal EPROM. The instruction is terminated by an interrupt event. When writing to external program memory, it is a two-cycle instruction. Two-cycle instruction when condition is true, else single cycle instruction. Two-cycle instruction except for TABLRD to PCL (program counter low byte), in which case it takes 3 cycles. A "skip" means that instruction fetched during execution of current instruction is not executed, instead a NOP is executed.
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PIC17C7XX
TABLE 18-2:
Mnemonic, Operands TSTFSZ XORWF f f,d
PIC17CXXX INSTRUCTION SET (CONTINUED)
16-bit Opcode Description Test f, skip if 0 Exclusive OR WREG with f Cycles MSb 1 (2) 1
0011 0000
LSb
0011 ffff ffff 110d ffff ffff
Status Affected None Z
Notes 6,8
BIT-ORIENTED FILE REGISTER OPERATIONS BCF BSF BTFSC BTFSS BTG f,b f,b f,b f,b f,b Bit Clear f Bit Set f Bit test, skip if clear Bit test, skip if set Bit Toggle f 1 1 1 (2) 1 (2) 1
1000 1000 1001 1001 0011 1bbb ffff ffff 0bbb ffff ffff 1bbb ffff ffff 0bbb ffff ffff 1bbb ffff ffff
None None None None None 6,8 6,8
LITERAL AND CONTROL OPERATIONS ADDLW ANDLW CALL CLRWDT GOTO IORLW LCALL MOVLB MOVLR MOVLW MULLW RETFIE RETLW RETURN SLEEP SUBLW XORLW Legend: Note 1: 2: 3: 4: 5: 6: 7: 8: k k k -- k k k k k k k -- k -- -- k k ADD literal to WREG AND literal with WREG Subroutine Call Clear Watchdog Timer Unconditional Branch Inclusive OR literal with WREG Long Call Move literal to low nibble in BSR Move literal to high nibble in BSR Move literal to WREG Multiply literal with WREG Return from interrupt (and enable interrupts) Return literal to WREG Return from subroutine Enter SLEEP mode Subtract WREG from literal Exclusive OR literal with WREG 1 1 2 1 2 1 2 1 1 1 1 2 2 2 1 1 1
1011 1011 111k 0000 110k 1011 1011 1011 1011 1011 1011 0000 1011 0000 0000 1011 1011 0001 kkkk kkkk 0101 kkkk kkkk kkkk kkkk kkkk 0000 0000 0100 kkkk kkkk kkkk 0011 kkkk kkkk 0111 kkkk kkkk 1000 uuuu kkkk 101x kkkk uuuu 0000 kkkk kkkk 1100 kkkk kkkk 0000 0000 0101 0110 kkkk kkkk 0000 0000 0010 0000 0000 0011 0010 kkkk kkkk 0100 kkkk kkkk
OV,C,DC,Z Z None TO, PD None Z None None None None None GLINTD None None TO, PD OV,C,DC,Z Z 7 7 7 4,7 7 7
Refer to Table 18-1 for opcode field descriptions. 2's Complement method. Unsigned arithmetic. If s = '1', only the file is affected: If s = '0', both the WREG register and the file are affected; If only the Working register (WREG) is required to be affected, then f = WREG must be specified. During an LCALL, the contents of PCLATH are loaded into the MSB of the PC and kkkk kkkk is loaded into the LSB of the PC (PCL). Multiple cycle instruction for EPROM programming when table pointer selects internal EPROM. The instruction is terminated by an interrupt event. When writing to external program memory, it is a two-cycle instruction. Two-cycle instruction when condition is true, else single cycle instruction. Two-cycle instruction except for TABLRD to PCL (program counter low byte), in which case it takes 3 cycles. A "skip" means that instruction fetched during execution of current instruction is not executed, instead a NOP is executed.
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PIC17C7XX
ADDLW Syntax: Operands: Operation: Status Affected: Encoding: Description: ADD Literal to WREG [ label ] ADDLW 0 k 255 (WREG) + k (WREG) OV, C, DC, Z
1011 0001 kkkk kkkk
ADDWF Syntax: Operands: Operation: Status Affected: Encoding: Description:
ADD WREG to f [ label ] ADDWF 0 f 255 d [0,1] (WREG) + (f) (dest) OV, C, DC, Z
0000 111d ffff ffff
k
f,d
The contents of WREG are added to the 8-bit literal 'k' and the result is placed in WREG.
:RUGV &\FOHV Q Cycle Activity: Q1
Decode
Q2
Read literal 'k'
ADDLW
Add WREG to register 'f'. If 'd' is 0 the result is stored in WREG. If 'd' is 1 the result is stored back in register 'f'.
Words: Cycles: Q3
Process Data
0x15
1 1 Q1
Decode
Q4
Write to WREG
Q Cycle Activity: Q2
Read register 'f'
ADDWF
Q3
Process Data
REG, 0
Q4
Write to destination
Example:
Before Instruction
WREG = 0x10
Example:
WREG REG WREG REG = = = =
Before Instruction
0x17 0xC2 0xD9 0xC2
After Instruction
WREG = 0x25
After Instruction
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PIC17C7XX
ADDWFC Syntax: Operands: Operation: Status Affected: Encoding: Description: ADD WREG and Carry bit to f [ label ] ADDWFC 0 f 255 d [0,1] (WREG) + (f) + C (dest) OV, C, DC, Z
0001 000d ffff ffff
ANDLW Syntax: Operands: Operation: Status Affected: Encoding: Description:
And Literal with WREG [ label ] ANDLW 0 k 255 (WREG) .AND. (k) (WREG) Z
1011 0101 kkkk kkkk
f,d
k
Add WREG, the Carry Flag and data memory location 'f'. If 'd' is 0, the result is placed in WREG. If 'd' is 1, the result is placed in data memory location 'f'.
The contents of WREG are AND'ed with the 8-bit literal 'k'. The result is placed in WREG.
Words: Cycles: Q Cycle Activity: Q1
1 1 Q2
Read literal 'k'
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
Q3
Process Data
Q4
Write to WREG
Q3
Process Data
Q4
Write to destination
Decode
Example: Example:
Carry bit = REG = WREG =
ADDWFC REG 0
ANDLW
0x5F
Before Instruction
WREG WREG = = 0xA3 0x03
Before Instruction
1 0x02 0x4D 0 0x02 0x50
After Instruction
After Instruction
Carry bit = REG = WREG =
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DS30289B-page 203
PIC17C7XX
ANDWF Syntax: Operands: Operation: Status Affected: Encoding: Description: AND WREG with f [ label ] ANDWF 0 f 255 d [0,1] (WREG) .AND. (f) (dest) Z
0000 101d ffff ffff
BCF f,d Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1
Decode
Bit Clear f [ label ] BCF 0 f 255 0b7 0 (f) None
1000 1bbb ffff ffff
f,b
The contents of WREG are AND'ed with register 'f'. If 'd' is 0 the result is stored in WREG. If 'd' is 1 the result is stored back in register 'f'.
Bit 'b' in register 'f' is cleared.
1 1 Q2
Read register 'f'
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
Q3
Process Data
Q4
Write register 'f'
Q3
Process Data
Q4
Write to destination
Example:
BCF
FLAG_REG,
7
Before Instruction Example:
WREG REG WREG REG = = = =
ANDWF REG, 1
FLAG_REG = 0xC7
Before Instruction
0x17 0xC2 0x17 0x02
After Instruction
FLAG_REG = 0x47
After Instruction
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PIC17C7XX
BSF Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1
Decode
Bit Set f [ label ] BSF 0 f 255 0b7 1 (f) None
1000 0bbb ffff ffff
BTFSC f,b Syntax: Operands: Operation: Status Affected: Encoding: Description:
Bit Test, skip if Clear [ label ] BTFSC f,b 0 f 255 0b7 skip if (f) = 0 None
1001 1bbb ffff ffff
Bit 'b' in register 'f' is set.
1 1 Q2
Read register 'f'
If bit 'b' in register 'f' is 0, then the next instruction is skipped. If bit 'b' is 0, then the next instruction fetched during the current instruction execution is discarded and a NOP is executed instead, making this a two-cycle instruction.
Q3
Process Data
Q4
Write register 'f'
Words: Cycles: Q Cycle Activity:
1 1(2) Q1
Decode
Example:
BSF
FLAG_REG, 7
Q2
Read register 'f'
Q3
Process Data
Q4
No operation
Before Instruction
FLAG_REG = = 0x0A 0x8A
After Instruction
FLAG_REG
If skip: Q1
No operation
Q2
No operation
Q3
No operation
Q4
No operation
Example:
HERE FALSE TRUE
BTFSC : :
FLAG,1
Before Instruction
PC = = = = = address (HERE) 0; address (TRUE) 1; address (FALSE)
After Instruction
If FLAG<1> PC If FLAG<1> PC
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PIC17C7XX
BTFSS Syntax: Operands: Operation: Status Affected: Encoding: Description: Bit Test, skip if Set [ label ] BTFSS f,b 0 f 127 0b<7 skip if (f) = 1 None
1001 0bbb ffff ffff
BTG Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1
Decode
Bit Toggle f [ label ] BTG f,b 0 f 255 0b<7 (f) (f) None
0011 1bbb ffff ffff
If bit 'b' in register 'f' is 1, then the next instruction is skipped. If bit 'b' is 1, then the next instruction fetched during the current instruction execution is discarded and a NOP is executed instead, making this a two-cycle instruction.
Bit 'b' in data memory location 'f' is inverted.
1 1 Q2
Read register 'f'
Q3
Process Data
Q4
Write register 'f'
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1(2) Q2
Read register 'f'
Q3
Process Data
Q4
No operation
Example:
PORTC PORTC = =
BTG
PORTC,
4
Before Instruction:
0111 0101 [0x75] 0110 0101 [0x65]
If skip: Q1
No operation
After Instruction: Q2
No operation
Q3
No operation
Q4
No operation
Example:
HERE FALSE TRUE
BTFSS : :
FLAG,1
Before Instruction
PC = = = = = address (HERE) 0; address (FALSE) 1; address (TRUE)
After Instruction
If FLAG<1> PC If FLAG<1> PC
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PIC17C7XX
CALL Syntax: Operands: Operation: Subroutine Call [ label ] CALL k 0 k 8191 PC+ 1 TOS, k PC<12:0>, k<12:8> PCLATH<4:0>; PC<15:13> PCLATH<7:5> None
111k kkkk kkkk kkkk
CLRF Syntax: Operands: Operation: Status Affected: Encoding: Description:
Clear f [label] CLRF 0 f 255 00h f, s [0,1] 00h dest None
0010 100s ffff ffff
f,s
Status Affected: Encoding: Description:
Subroutine call within 8K page. First, return address (PC+1) is pushed onto the stack. The 13-bit value is loaded into PC bits<12:0>. Then the uppereight bits of the PC are copied into PCLATH. CALL is a two-cycle instruction. See LCALL for calls outside 8K memory space.
Clears the contents of the specified register(s). s = 0: Data memory location 'f' and WREG are cleared. s = 1: Data memory location 'f' is cleared.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
Words: Cycles: Q Cycle Activity: Q1
Decode
1 2 Q2
Read literal 'k'<7:0>, Push PC to stack No operation
Q3
Process Data
Q4
Write register 'f' and if specified WREG
Q3
Process Data
Q4
Write to PC
Example:
No operation No operation
CLRF
FLAG_REG, 1
No operation
Before Instruction
FLAG_REG WREG = = = = 0x5A 0x01 0x00 0x01
Example:
PC = PC = TOS =
HERE
CALL
THERE
After Instruction
FLAG_REG WREG
Before Instruction
Address(HERE) Address(THERE) Address (HERE + 1)
After Instruction
2000 Microchip Technology Inc.
DS30289B-page 207
PIC17C7XX
CLRWDT Syntax: Operands: Operation: Clear Watchdog Timer [ label ] CLRWDT None 00h WDT 0 WDT postscaler, 1 TO 1 PD TO, PD
0000 0000 0000 0100 CLRWDT instruction resets the Watchdog Timer. It also resets the postscaler of the WDT. Status bits TO and PD are set.
COMF Syntax: Operands: Operation: Status Affected: Encoding: Description:
Complement f [ label ] COMF 0 f 255 d [0,1] ( f ) (dest) Z
0001 001d ffff ffff
f,d
Status Affected: Encoding: Description:
The contents of register 'f' are complemented. If 'd' is 0 the result is stored in WREG. If 'd' is 1 the result is stored back in register 'f'.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
No operation
Q3
Process Data
Q4
Write to destination
Q3
Process Data
Q4
No operation
Example: Example:
CLRWDT
COMF
REG1,0
Before Instruction
REG1 = = = = = ? 0x00 0 1 1 REG1 WREG = = = 0x13 0x13 0xEC
Before Instruction
WDT counter
After Instruction
After Instruction
WDT counter WDT Postscaler
TO PD
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PIC17C7XX
CPFSEQ Syntax: Operands: Operation: Compare f with WREG, skip if f = WREG [ label ] CPFSEQ 0 f 255 (f) - (WREG), skip if (f) = (WREG) (unsigned comparison) None
0011 0001 ffff ffff
CPFSGT Syntax: Operands: Operation:
Compare f with WREG, skip if f > WREG [ label ] CPFSGT 0 f 255 (f) - (WREG), skip if (f) > (WREG) (unsigned comparison) None
0011 0010 ffff ffff
f
f
Status Affected: Encoding: Description:
Status Affected: Encoding: Description:
Compares the contents of data memory location 'f' to the contents of WREG by performing an unsigned subtraction. If 'f' = WREG, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction.
Compares the contents of data memory location 'f' to the contents of the WREG by performing an unsigned subtraction. If the contents of 'f' are greater than the contents of WREG, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 (2) Q2
Read register 'f'
Words: Cycles: Q3
Process Data
1 1 (2) Q1
Decode
Q4
No operation
Q Cycle Activity: Q2
Read register 'f'
Q3
Process Data
Q4
No operation
If skip: Q1
No operation
Q2
No operation
Q3
No operation
Q4
No operation
If skip: Q1
No operation
Q2
No operation
Q3
No operation
Q4
No operation
Example:
HERE NEQUAL EQUAL
CPFSEQ REG : : HERE ? ?
Example:
Before Instruction
PC Address WREG REG = = = = = = PC WREG
HERE NGREATER GREATER
CPFSGT REG : :
Before Instruction
= = > = = Address (HERE) ? WREG; Address (GREATER) WREG; Address (NGREATER)
After Instruction
If REG PC If REG PC WREG; Address (EQUAL) WREG; Address (NEQUAL)
After Instruction
If REG PC If REG PC
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PIC17C7XX
CPFSLT Syntax: Operands: Operation: Compare f with WREG, skip if f < WREG [ label ] CPFSLT 0 f 255 (f) - (WREG), skip if (f) < (WREG) (unsigned comparison) None
0011 0000 ffff ffff
DAW Syntax: Operands: Operation:
Decimal Adjust WREG Register [label] DAW 0 f 255 s [0,1]
If [ [WREG<7:4> > 9].OR.[C = 1] ].AND. [WREG<3:0> > 9] then WREG<7:4> + 7 f<7:4>, s<7:4>; If [WREG<7:4> > 9].OR.[C = 1] then WREG<7:4> + 6 f<7:4>, s<7:4>; else WREG<7:4> f<7:4>, s<7:4>; If [WREG<3:0> > 9].OR.[DC = 1] then WREG<3:0> + 6 f<3:0>, s<3:0>; else WREG<3:0> f<3:0>, s<3:0>
f
f,s
Status Affected: Encoding: Description:
Compares the contents of data memory location 'f' to the contents of WREG by performing an unsigned subtraction. If the contents of 'f' are less than the contents of WREG, then the fetched instruction is discarded and a NOP is executed instead, making this a two-cycle instruction.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 (2) Q2
Read register 'f'
Status Affected: Q3
Process Data
C
0010 111s ffff ffff
Q4
No operation
Encoding: Description:
If skip: Q1
No operation
Q2
No operation
Q3
No operation
Q4
No operation
DAW adjusts the eight-bit value in WREG, resulting from the earlier addition of two variables (each in packed BCD format) and produces a correct packed BCD result. s = 0: Result is placed in Data memory location 'f' and WREG. s = 1: Result is placed in Data memory location 'f'.
Example:
HERE NLESS LESS
CPFSLT REG : :
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
Before Instruction
PC W = = < = = Address (HERE) ? WREG; Address (LESS) WREG; Address (NLESS)
Q3
Process Data
Q4
Write register 'f' and other specified register
After Instruction
If REG PC If REG PC
Example:
WREG REG1 C DC WREG REG1 C DC = = = = = = = =
DAW
REG1, 0
Before Instruction
0xA5 ?? 0 0 0x05 0x05 1 0
After Instruction
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PIC17C7XX
DECF Syntax: Operands: Operation: Status Affected: Encoding: Description: Decrement f [ label ] DECF f,d 0 f 255 d [0,1] (f) - 1 (dest) OV, C, DC, Z
0000 011d ffff ffff
DECFSZ Syntax: Operands: Operation: Status Affected: Encoding: Description:
Decrement f, skip if 0 [ label ] DECFSZ f,d 0 f 255 d [0,1] (f) - 1 (dest); skip if result = 0 None
0001 011d ffff ffff
Decrement register 'f'. If 'd' is 0, the result is stored in WREG. If 'd' is 1, the result is stored back in register 'f'.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
The contents of register 'f' are decremented. If 'd' is 0, the result is placed in WREG. If 'd' is 1, the result is placed back in register 'f'. If the result is 0, the next instruction, which is already fetched is discarded and a NOP is executed instead, making it a two-cycle instruction.
Q3
Process Data
Q4
Write to destination
Words: Cycles: Q Cycle Activity: Q1
1 1(2) Q2
Read register 'f'
Example:
CNT Z CNT Z = = = =
DECF
CNT,
1
Before Instruction
0x01 0
Q3
Process Data
Q4
Write to destination
Decode
After Instruction
0x00 1
If skip: Q1
No operation
Q2
No operation
Q3
No operation
Q4
No operation
Example:
HERE NZERO ZERO
DECFSZ GOTO
CNT, 1 HERE
Before Instruction
PC CNT If CNT PC If CNT PC = = = = = Address (HERE) CNT - 1 0; Address (HERE) 0; Address (NZERO)
After Instruction
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PIC17C7XX
DCFSNZ Syntax: Operands: Operation: Status Affected: Encoding: Description: Decrement f, skip if not 0 [label] DCFSNZ f,d 0 f 255 d [0,1] (f) - 1 (dest); skip if not 0 None
0010 011d ffff ffff
GOTO Syntax: Operands: Operation:
Unconditional Branch [ label ] GOTO k 0 k 8191 k PC<12:0>; k<12:8> PCLATH<4:0>, PC<15:13> PCLATH<7:5> None
110k kkkk kkkk kkkk GOTO allows an unconditional branch anywhere within an 8K page boundary. The thirteen-bit immediate value is loaded into PC bits <12:0>. Then the upper eight bits of PC are loaded into PCLATH. GOTO is always a two-cycle instruction.
Status Affected: Encoding: Description:
The contents of register 'f' are decremented. If 'd' is 0, the result is placed in WREG. If 'd' is 1, the result is placed back in register 'f'. If the result is not 0, the next instruction, which is already fetched is discarded and a NOP is executed instead, making it a two-cycle instruction.
Words: Cycles: Q Cycle Activity: Q1
1 2 Q2
Read literal 'k' No operation
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1(2) Q2
Read register 'f'
Q3
Process Data No operation
Q4
Write to PC No operation
Q3
Process Data
Q4
Write to destination
Decode No operation
If skip: Q1
No operation
Q2
No operation
Q3
No operation
Q4
No operation
Example:
PC =
GOTO THERE
After Instruction
Address (THERE)
Example:
HERE ZERO NZERO
DCFSNZ : :
TEMP, 1
Before Instruction
TEMP_VALUE = = = = = ? TEMP_VALUE - 1, 0; Address (ZERO) 0; Address (NZERO)
After Instruction
TEMP_VALUE If TEMP_VALUE PC If TEMP_VALUE PC
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PIC17C7XX
INCF Syntax: Operands: Operation: Status Affected: Encoding: Description: Increment f [ label ] INCF f,d 0 f 255 d [0,1] (f) + 1 (dest) OV, C, DC, Z
0001 010d ffff ffff
INCFSZ Syntax: Operands: Operation: Status Affected: Encoding: Description:
Increment f, skip if 0 [ label ] INCFSZ f,d 0 f 255 d [0,1] (f) + 1 (dest) skip if result = 0 None
0001 111d ffff ffff
The contents of register 'f' are incremented. If 'd' is 0, the result is placed in WREG. If 'd' is 1, the result is placed back in register 'f'.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
The contents of register 'f' are incremented. If 'd' is 0, the result is placed in WREG. If 'd' is 1, the result is placed back in register 'f'. If the result is 0, the next instruction, which is already fetched is discarded and a NOP is executed instead, making it a two-cycle instruction.
Q3
Process Data
Q4
Write to destination
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1(2) Q2
Read register 'f'
Example:
CNT Z C CNT Z C = = = = = =
INCF
CNT, 1
Q3
Process Data
Q4
Write to destination
Before Instruction
0xFF 0 ? 0x00 1 1
If skip: Q1
No operation
After Instruction
Q2
No operation
Q3
No operation
Q4
No operation
Example:
HERE NZERO ZERO
INCFSZ : :
CNT, 1
Before Instruction
PC CNT If CNT PC If CNT PC = = = = = Address (HERE) CNT + 1 0; Address(ZERO) 0; Address(NZERO)
After Instruction
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PIC17C7XX
INFSNZ Syntax: Operands: Operation: Status Affected: Encoding: Description: Increment f, skip if not 0 [label] INFSNZ f,d 0 f 255 d [0,1] (f) + 1 (dest), skip if not 0 None
0010 010d ffff ffff
IORLW Syntax: Operands: Operation: Status Affected: Encoding: Description:
Inclusive OR Literal with WREG [ label ] IORLW k 0 k 255 (WREG) .OR. (k) (WREG) Z
1011 0011 kkkk kkkk
The contents of register 'f' are incremented. If 'd' is 0, the result is placed in WREG. If 'd' is 1, the result is placed back in register 'f'. If the result is not 0, the next instruction, which is already fetched is discarded and a NOP is executed instead, making it a two-cycle instruction.
The contents of WREG are OR'ed with the eight-bit literal 'k'. The result is placed in WREG.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read literal 'k'
Q3
Process Data
Q4
Write to WREG
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1(2) Example: Q2
Read register 'f'
IORLW
0x35
Q3
Process Data
Q4
Write to destination
Before Instruction
WREG WREG = = 0x9A 0xBF
After Instruction
If skip: Q1
No operation
Q2
No operation
Q3
No operation
Q4
No operation
Example:
HERE ZERO NZERO
INFSNZ
REG, 1
Before Instruction
REG REG If REG PC If REG PC = = = = = = REG REG + 1 1; Address (ZERO) 0; Address (NZERO)
After Instruction
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PIC17C7XX
IORWF Syntax: Operands: Operation: Status Affected: Encoding: Description: Inclusive OR WREG with f [ label ] IORWF f,d 0 f 255 d [0,1] (WREG) .OR. (f) (dest) Z
0000 100d ffff ffff
LCALL Syntax: Operands: Operation: Status Affected: Encoding: Description:
Long Call [ label ] LCALL k 0 k 255 PC + 1 TOS; k PCL, (PCLATH) PCH None
1011 0111 kkkk kkkk LCALL allows an unconditional subroutine call to anywhere within the 64K program memory space.
Inclusive OR WREG with register 'f'. If 'd' is 0, the result is placed in WREG. If 'd' is 1, the result is placed back in register 'f'.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
Q3
Process Data
Q4
Write to destination
First, the return address (PC + 1) is pushed onto the stack. A 16-bit destination address is then loaded into the program counter. The lower 8-bits of the destination address are embedded in the instruction. The upper 8-bits of PC are loaded from PC high holding latch, PCLATH.
Words: Cycles: Q Cycle Activity: Q1
1 2 Q2
Read literal 'k' No operation
Example:
RESULT = WREG =
IORWF
RESULT, 0
Before Instruction
0x13 0x91 0x13 0x93
Q3
Process Data No operation
Q4
Write register PCL No operation
Decode No operation
After Instruction
RESULT = WREG =
Example:
MOVLW MOVPF LCALL
HIGH(SUBROUTINE) WREG, PCLATH LOW(SUBROUTINE)
Before Instruction
SUBROUTINE = PC =
16-bit Address ? Address (SUBROUTINE)
After Instruction
PC =
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PIC17C7XX
MOVFP Syntax: Operands: Operation: Status Affected: Encoding: Description: Move f to p [label] MOVFP f,p 0 f 255 0 p 31 (f) (p) None
011p pppp ffff ffff
MOVLB Syntax: Operands: Operation: Status Affected: Encoding: Description:
Move Literal to low nibble in BSR [ label ] MOVLB k 0 k 15 k (BSR<3:0>) None
1011 1000 uuuu kkkk The four-bit literal 'k' is loaded in the Bank Select Register (BSR). Only the low 4-bits of the Bank Select Register are affected. The upper half of the BSR is unchanged. The assembler will encode the "u" fields as '0'.
Move data from data memory location 'f' to data memory location 'p'. Location 'f' can be anywhere in the 256 byte data space (00h to FFh), while 'p' can be 00h to 1Fh. Either 'p' or 'f' can be WREG (a useful, special situation).
MOVFP is particularly useful for transferring a data memory location to a peripheral register (such as the transmit buffer or an I/O port). Both 'f' and 'p' can be indirectly addressed.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read literal 'k'
Q3
Process Data
Q4
Write literal 'k' to BSR<3:0>
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Example: Q2
Read register 'f'
MOVLB = = 5 0x22 0x25 (Bank 5)
Q3
Process Data
Q4
Write register 'p'
Before Instruction
BSR register
After Instruction
BSR register
Example:
REG1 REG2
MOVFP
REG1, REG2
Before Instruction
= = = = 0x33, 0x11 0x33, 0x33
After Instruction
REG1 REG2
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PIC17C7XX
MOVLR Syntax: Operands: Operation: Status Affected: Encoding: Description: Move Literal to high nibble in BSR [ label ] MOVLR k 0 k 15 k (BSR<7:4>) None
1011 101x kkkk uuuu
MOVLW Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1
Decode
Move Literal to WREG [ label ] MOVLW k 0 k 255 k (WREG) None
1011 0000 kkkk kkkk
The 4-bit literal 'k' is loaded into the most significant 4-bits of the Bank Select Register (BSR). Only the high 4-bits of the Bank Select Register are affected. The lower half of the BSR is unchanged. The assembler will encode the "u" fields as 0.
The eight-bit literal 'k' is loaded into WREG.
1 1 Q2
Read literal 'k'
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read literal 'k'
Q3
Process Data
Q4
Write to WREG
Q3
Process Data
Q4
Write literal 'k' to BSR<7:4>
Example:
WREG =
MOVLW
0x5A
After Instruction
0x5A
Example:
MOVLR
5
Before Instruction
BSR register = = 0x22 0x52
After Instruction
BSR register
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PIC17C7XX
MOVPF Syntax: Operands: Operation: Status Affected: Encoding: Description: Move p to f [label] MOVPF p,f 0 f 255 0 p 31 (p) (f) Z
010p pppp ffff ffff
MOVWF Syntax: Operands: Operation: Status Affected: Encoding: Description:
Move WREG to f [ label ] MOVWF f 0 f 255 (WREG) (f) None
0000 0001 ffff ffff
Move data from data memory location 'p' to data memory location 'f'. Location 'f' can be anywhere in the 256 byte data space (00h to FFh), while 'p' can be 00h to 1Fh. Either 'p' or 'f' can be WREG (a useful, special situation).
MOVPF is particularly useful for transferring a peripheral register (e.g. the timer or an I/O port) to a data memory location. Both 'f' and 'p' can be indirectly addressed.
Move data from WREG to register 'f'. Location 'f' can be anywhere in the 256 byte data space.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
Q3
Process Data
Q4
Write register 'f'
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'p'
Example:
WREG REG = = = =
MOVWF
REG
Before Instruction
0x4F 0xFF 0x4F 0x4F
Q3
Process Data
Q4
Write register 'f'
After Instruction
WREG REG
Example:
REG1 REG2
MOVPF
REG1, REG2
Before Instruction
= = = = 0x11 0x33 0x11 0x11
After Instruction
REG1 REG2
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PIC17C7XX
MULLW Syntax: Operands: Operation: Status Affected: Encoding: Description: Multiply Literal with WREG [ label ] MULLW k 0 k 255 (k x WREG) PRODH:PRODL None
1011 1100 kkkk kkkk
MULWF Syntax: Operands: Operation: Status Affected: Encoding: Description:
Multiply WREG with f [ label ] MULWF f 0 f 255 (WREG x f) PRODH:PRODL None
0011 0100 ffff ffff
An unsigned multiplication is carried out between the contents of WREG and the 8-bit literal 'k'. The 16-bit result is placed in PRODH:PRODL register pair. PRODH contains the high byte. WREG is unchanged. None of the status flags are affected. Note that neither overflow, nor carry is possible in this operation. A zero result is possible, but not detected.
An unsigned multiplication is carried out between the contents of WREG and the register file location 'f'. The 16-bit result is stored in the PRODH:PRODL register pair. PRODH contains the high byte. Both WREG and 'f' are unchanged. None of the status flags are affected. Note that neither overflow, nor carry is possible in this operation. A zero result is possible, but not detected.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read literal 'k'
Words: Cycles: Q Cycle Activity: Q3
Process Data
1 1 Q1 Q2
Read register 'f'
Q4
Write registers PRODH: PRODL
Q3
Process Data
Q4
Write registers PRODH: PRODL
Decode
Example:
WREG PRODH PRODL
MULLW
0xC4
Example:
WREG REG PRODH PRODL
MULWF
REG
Before Instruction
= = = = = = 0xE2 ? ? 0xC4 0xAD 0x08
Before Instruction
= = = = = = = = 0xC4 0xB5 ? ? 0xC4 0xB5 0x8A 0x94
After Instruction
WREG PRODH PRODL
After Instruction
WREG REG PRODH PRODL
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PIC17C7XX
NEGW Syntax: Operands: Operation: Status Affected: Encoding: Description: Negate W [label] NEGW f,s 0 f 255 s [0,1] WREG + 1 (f); WREG + 1 s OV, C, DC, Z
0010 110s ffff ffff
NOP Syntax: Operands: Operation: Status Affected: Encoding: Description: Words: Cycles: Q Cycle Activity: Q1
Decode
No Operation [ label ] None No operation None
0000 0000 0000 0000
NOP
No operation.
WREG is negated using two's complement. If 's' is 0, the result is placed in WREG and data memory location 'f'. If 's' is 1, the result is placed only in data memory location 'f'.
1 1 Q2
No operation
Q3
No operation
Q4
No operation
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
Q3
Process Data
Q4
Write register 'f' and other specified register
Example:
None.
Example:
WREG REG WREG REG = = = =
NEGW
REG,0
Before Instruction
0011 1010 [0x3A], 1010 1011 [0xAB] 1100 0110 [0xC6] 1100 0110 [0xC6]
After Instruction
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PIC17C7XX
RETFIE Syntax: Operands: Operation: Return from Interrupt [ label ] None TOS (PC); 0 GLINTD; PCLATH is unchanged. GLINTD
0000 0000 0000 0101
RETLW Syntax: Operands: Operation: Status Affected: Encoding: Description:
Return Literal to WREG [ label ] RETLW k 0 k 255 k (WREG); TOS (PC); PCLATH is unchanged None
1011 0110 kkkk kkkk
RETFIE
Status Affected: Encoding: Description:
Return from Interrupt. Stack is POP'ed and Top-of-Stack (TOS) is loaded in the PC. Interrupts are enabled by clearing the GLINTD bit. GLINTD is the global interrupt disable bit (CPUSTA<4>).
WREG is loaded with the eight-bit literal 'k'. The program counter is loaded from the top of the stack (the return address). The high address latch (PCLATH) remains unchanged.
Words: Cycles: Q Cycle Activity: Q1
1 2 Q2
Read literal 'k'
Words: Cycles: Q Cycle Activity: Q1
Decode No operation
1 2 Q2
No operation No operation
Q3
Process Data
Q4
POP PC from stack, Write to WREG No operation
Q3
Clear GLINTD No operation
Q4
POP PC from stack No operation
Decode
No operation
No operation
No operation
Example: After Interrupt
PC = GLINTD =
RETFIE
Example:
TOS 0
CALL TABLE ; ; ; ; : TABLE ADDWF PC ; RETLW k0 ; RETLW k1 ; : : RETLW kn ;
WREG contains table offset value WREG now has table value WREG = offset Begin table
End of table
Before Instruction
WREG WREG = = 0x07 value of k7
After Instruction
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PIC17C7XX
RETURN Syntax: Operands: Operation: Status Affected: Encoding: Description: Return from Subroutine [ label ] None TOS PC; None
0000 0000 0000 0010
RLCF Syntax: Operands: Operation:
Rotate Left f through Carry [ label ] RLCF 0 f 255 d [0,1] f d; f<7> C; C d<0> C
0001 101d ffff ffff
RETURN
f,d
Return from subroutine. The stack is popped and the top of the stack (TOS) is loaded into the program counter.
Status Affected: Encoding: Description:
Words: Cycles: Q Cycle Activity: Q1
Decode No operation
1 2 Q2
No operation No operation
Q3
Process Data No operation
Q4
POP PC from stack No operation
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 WREG. If 'd' is 1, the result is stored back in register 'f'.
C Words: Cycles: Q Cycle Activity: Q1 Q2
Read register 'f'
register f
1 1 Q3
Process Data
Q4
Write to destination
Example: After Interrupt
RETURN
Decode
PC = TOS
Example:
REG C REG WREG C = = = = =
RLCF
REG,0
Before Instruction
1110 0110 0 1110 0110 1100 1100 1
After Instruction
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PIC17C7XX
RLNCF Syntax: Operands: Operation: Status Affected: Encoding: Description: Rotate Left f (no carry) [ label ] RLNCF 0 f 255 d [0,1] f d; f<7> d<0> None
0010 001d ffff ffff
RRCF Syntax: Operands: Operation:
Rotate Right f through Carry [ label ] RRCF f,d 0 f 255 d [0,1] f d; f<0> C; C d<7> C
0001 100d ffff ffff
f,d
Status Affected: Encoding: Description:
The contents of register 'f' are rotated one bit to the left. If 'd' is 0, the result is placed in WREG. If 'd' is 1, the result is stored back in register 'f'.
register f
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 WREG. If 'd' is 1, the result is placed back in register 'f'.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
C Words: Q3
Process Data
register f
1 1 Q1
Decode
Q4
Write to destination
Cycles: Q Cycle Activity:
Q2
Read register 'f'
Q3
Process Data
Q4
Write to destination
Example:
C REG C REG = = = =
RLNCF
REG, 1
Before Instruction
0 1110 1011
Example:
REG1 C = = = = =
RRCF REG1,0 1110 0110 0 1110 0110 0111 0011 0
Before Instruction
After Instruction
1101 0111
After Instruction
REG1 WREG C
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PIC17C7XX
RRNCF Syntax: Operands: Operation: Status Affected: Encoding: Description: Rotate Right f (no carry) [ label ] RRNCF f,d 0 f 255 d [0,1] f d; f<0> d<7> None
0010 000d ffff ffff
SETF Syntax: Operands: Operation: Status Affected: Encoding: Description:
Set f [ label ] SETF f,s 0 f 255 s [0,1] FFh f; FFh d None
0010 101s ffff ffff
The contents of register 'f' are rotated one bit to the right. If 'd' is 0, the result is placed in WREG. If 'd' is 1, the result is placed back in register 'f'.
register f
If 's' is 0, both the data memory location 'f' and WREG are set to FFh. If 's' is 1, only the data memory location 'f' is set to FFh.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
Q3
Process Data
Q4
Write register 'f' and other specified register
Q3
Process Data
Q4
Write to destination
Example 1:
WREG REG WREG REG = = = =
RRNCF
REG, 1
Before Instruction
? 1101 0111
0 1110 1011 RRNCF = = = = REG, 0
Example1:
REG WREG REG WREG = =
SETF
REG, 0
Before Instruction
0xDA 0x05
After Instruction
After Instruction
= 0xFF = 0xFF SETF REG, 1 = = = = 0xDA 0x05 0xFF 0x05
Example 2:
WREG REG WREG REG
Example2:
REG WREG REG WREG
Before Instruction
? 1101 0111 1110 1011 1101 0111
Before Instruction
After Instruction
After Instruction
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PIC17C7XX
SLEEP Syntax: Operands: Operation: Enter SLEEP mode [ label ] SLEEP None 00h WDT; 0 WDT postscaler; 1 TO; 0 PD TO, PD
0000 0000 0000 0011
SUBLW Syntax: Operands: Operation: Status Affected: Encoding: Description:
Subtract WREG from Literal [ label ] SUBLW k 0 k 255 k - (WREG) (WREG) OV, C, DC, Z
1011 0010 kkkk kkkk
Status Affected: Encoding: Description:
WREG is subtracted from the eight-bit literal 'k'. The result is placed in WREG.
The power-down status bit (PD) is cleared. The time-out status bit (TO) is set. Watchdog Timer and its postscaler are cleared. The processor is put into SLEEP mode with the oscillator stopped.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read literal 'k'
SUBLW
Q3
Process Data
0x02
Q4
Write to WREG
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Example 1: Q2
No operation
Q3
Process Data
Q4
Go to sleep
Before Instruction
WREG C WREG C Z = = = = = 1 ? 1 1 0
After Instruction Example:
TO = PD = TO = PD = ? ? 1 0
SLEEP
; result is positive
Before Instruction
Example 2: Before Instruction
WREG C WREG C Z = = = = = 2 ? 0 1 1
After Instruction
After Instruction
; result is zero
If WDT causes wake-up, this bit is cleared
Example 3: Before Instruction
WREG C WREG C Z = = = = = 3 ? FF ; (2's complement) 0 ; result is negative 0
After Instruction
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PIC17C7XX
SUBWF Syntax: Operands: Operation: Status Affected: Encoding: Description: Subtract WREG from f [ label ] SUBWF f,d 0 f 255 d [0,1] (f) - (W) (dest) OV, C, DC, Z
0000 010d ffff ffff
SUBWFB Syntax: Operands: Operation: Status Affected: Encoding: Description:
Subtract WREG from f with Borrow [ label ] SUBWFB f,d 0 f 255 d [0,1] (f) - (W) - C (dest) OV, C, DC, Z
0000 001d ffff ffff
Subtract WREG from register 'f' (2's complement method). If 'd' is 0, the result is stored in WREG. If 'd' is 1, the result is stored back in register 'f'.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
Subtract WREG and the carry flag (borrow) from register 'f' (2's complement method). If 'd' is 0, the result is stored in WREG. If 'd' is 1, the result is stored back in register 'f'.
Words: Cycles: Q3
Process Data
1 1 Q1
Decode
Q4
Write to destination
Q Cycle Activity: Q2
Read register 'f'
Q3
Process Data
Q4
Write to destination
Example 1:
REG1 WREG C REG1 WREG C Z = = = = = = =
SUBWF
REG1, 1
Example 1:
REG1 WREG C REG1 WREG C Z = = = = = = =
SUBWFB
REG1, 1 (0001 1001) (0000 1101)
Before Instruction
3 2 ? 1 2 1 0
Before Instruction
0x19 0x0D 1 0x0C 0x0D 1 0
After Instruction
After Instruction
; result is positive
(0000 1011) (0000 1101) ; result is positive REG1,0 (0001 1011) (0001 1010)
Example 2: Before Instruction
REG1 WREG C REG1 WREG C Z = = = = = = = 2 2 ? 0 2 1 1
Example2:
REG1 WREG C REG1 WREG C Z
SUBWFB
Before Instruction
= = = = = = = 0x1B 0x1A 0 0x1B 0x00 1 1
After Instruction
After Instruction
(0001 1011)
; result is zero
; result is zero
REG1,1 (0000 0011) (0000 1101)
Example 3: Before Instruction
REG1 WREG C REG1 WREG C Z = = = = = = = 1 2 ? FF 2 0 0
Example3:
REG1 WREG C REG1 WREG C Z
SUBWFB
Before Instruction
= = = = = = = 0x03 0x0E 1 0xF5 0x0E 0 0
After Instruction
After Instruction
; result is negative
(1111 0100) [2's comp] (0000 1101) ; result is negative
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PIC17C7XX
SWAPF Syntax: Operands: Operation: Status Affected: Encoding: Description: Swap f [ label ] SWAPF f,d 0 f 255 d [0,1] f<3:0> dest<7:4>; f<7:4> dest<3:0> None
0001 110d ffff ffff
TABLRD Syntax: Operands:
Table Read [ label ] TABLRD t,i,f 0 f 255 i [0,1] t [0,1] If t = 1, TBLATH f; If t = 0, TBLATL f; Prog Mem (TBLPTR) TBLAT; If i = 1, TBLPTR + 1 TBLPTR If i = 0, TBLPTR is unchanged None
1010 10ti ffff ffff
Operation:
The upper and lower nibbles of register 'f' are exchanged. If 'd' is 0, the result is placed in WREG. If 'd' is 1, the result is placed in register 'f'.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
Status Affected: Encoding: Q3
Process Data
Q4
Write to destination
Description:
1.
A byte of the table latch (TBLAT) is moved to register file 'f'. If t = 1: the high byte is moved; If t = 0: the low byte is moved. Then, the contents of the program memory location pointed to by the 16-bit Table Pointer (TBLPTR) are loaded into the 16-bit Table Latch (TBLAT). If i = 1: TBLPTR is incremented; If i = 0: TBLPTR is not incremented.
2.
Example:
REG REG = =
SWAPF
REG,
0
Before Instruction
0x53 3. 0x35
After Instruction
Words: Cycles: Q Cycle Activity: Q1
Decode
1 2 (3-cycle if f = PCL) Q2
Read register TBLATH or TBLATL No operation (Table Pointer on Address bus)
Q3
Process Data
Q4
Write register 'f'
No operation
No operation
No operation (OE goes low)
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PIC17C7XX
TABLRD Example1: Table Read
TABLRD 1, 1, REG ;
TABLWT Syntax: Operands:
= = = = = = = = = = 0x53 0xAA 0x55 0xA356 0x1234 0xAA 0x12 0x34 0xA357 0x5678
Table Write [ label ] TABLWT t,i,f 0 f 255 i [0,1] t [0,1] If t = 0, f TBLATL; If t = 1, f TBLATH; TBLAT Prog Mem (TBLPTR); If i = 1, TBLPTR + 1 TBLPTR If i = 0, TBLPTR is unchanged None
1010 11ti ffff ffff
Before Instruction
REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR) REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR)
Operation:
After Instruction (table write completion)
Example2:
TABLRD
0, 0, REG ;
Before Instruction
REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR) REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR) = = = = = = = = = = 0x53 0xAA 0x55 0xA356 0x1234 0x55 0x12 0x34 0xA356 0x1234
Status Affected: Encoding: Description:
1.
Load value in 'f' into 16-bit table latch (TBLAT) If t = 1: load into high byte; If t = 0: load into low byte The contents of TBLAT are written to the program memory location pointed to by TBLPTR. If TBLPTR points to external program memory location, then the instruction takes two-cycle. If TBLPTR points to an internal EPROM location, then the instruction is terminated when an interrupt is received.
After Instruction (table write completion)
2.
Note:
The MCLR/VPP pin must be at the programming voltage for successful programming of internal memory. If MCLR/VPP = VDD the programming sequence of internal memory will be interrupted. A short write will occur (2 TCY). The internal memory location will not be affected. 3. The TBLPTR can be automatically incremented If i = 1; TBLPTR is not incremented If i = 0; TBLPTR is incremented
Words: Cycles: Q Cycle Activity: Q1
Decode
1 2 (many if write is to on-chip EPROM program memory) Q2
Read register 'f'
Q3
Process Data
Q4
Write register TBLATH or TBLATL
No operation
No No No operation operation operation (Table Pointer (Table Latch on on Address Address bus, bus) WR goes low)
DS30289B-page 228
2000 Microchip Technology Inc.
PIC17C7XX
TABLWT Example1: Table Write
TABLWT 1, 1, REG
TLRD Syntax: Operands:
= = = = = = = = = = 0x53 0xAA 0x55 0xA356 0xFFFF 0x53 0x53 0x55 0xA357 0x5355
Table Latch Read [ label ] TLRD t,f 0 f 255 t [0,1] If t = 0, TBLATL f; If t = 1, TBLATH f None
1010 00tx ffff ffff
Before Instruction
REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR) REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR - 1)
Operation:
After Instruction (table write completion) Status Affected: Encoding: Description:
Example 2:
TABLWT
0, 0, REG
Read data from 16-bit table latch (TBLAT) into file register 'f'. Table Latch is unaffected. If t = 1; high byte is read If t = 0; low byte is read This instruction is used in conjunction with TABLRD to transfer data from program memory to data memory.
Before Instruction
REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR) REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR) = = = = = = = = = = 0x53 0xAA 0x55 0xA356 0xFFFF 0x53 0xAA 0x53 0xA356 0xAA53
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register TBLATH or TBLATL
After Instruction (table write completion)
Q3
Process Data
Q4
Write register 'f'
Program Memory
15 TBLPTR 15 8 7
0
Data Memory
Example:
0
TLRD
t, RAM
Before Instruction
t RAM TBLAT
8 bits
= = =
0 ? 0x00AF
16 bits
TBLAT
(TBLATH = 0x00) (TBLATL = 0xAF)
After Instruction
RAM TBLAT = = 0xAF 0x00AF (TBLATH = 0x00) (TBLATL = 0xAF)
Before Instruction
t RAM TBLAT = = = 1 ? 0x00AF
(TBLATH = 0x00) (TBLATL = 0xAF)
After Instruction
RAM TBLAT = = 0x00 0x00AF (TBLATH = 0x00) (TBLATL = 0xAF)
0 TBLPTR 15 8 7 0 Data Memory
Program Memory
15
16 bits
TBLAT
8 bits
2000 Microchip Technology Inc.
DS30289B-page 229
PIC17C7XX
TLWT Syntax: Operands: Operation: Table Latch Write [ label ] TLWT t,f 0 f 255 t [0,1] If t = 0, f TBLATL; If t = 1, f TBLATH None
1010 01tx ffff ffff
TSTFSZ Syntax: Operands: Operation: Status Affected: Encoding: Description:
Test f, skip if 0 [ label ] TSTFSZ f 0 f 255 skip if f = 0 None
0011 0011 ffff ffff
Status Affected: Encoding: Description:
If 'f' = 0, the next instruction, fetched during the current instruction execution, is discarded and a NOP is executed, making this a two-cycle instruction.
Data from file register 'f' is written into the 16-bit table latch (TBLAT). If t = 1; high byte is written If t = 0; low byte is written This instruction is used in conjunction with TABLWT to transfer data from data memory to program memory.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 (2) Q2
Read register 'f'
Q3
Process Data
Q4
No operation
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read register 'f'
If skip: Q1 Q3
Process Data
Q2
No operation
Q3
No operation
Q4
No operation
Q4
Write register TBLATH or TBLATL
No operation
Example:
HERE NZERO ZERO
TSTFSZ : :
CNT
Before Instruction Example:
t RAM TBLAT = = =
TLWT t, RAM
PC = Address (HERE)
Before Instruction
0 0xB7 0x0000
After Instruction
If CNT PC If CNT PC = = 1/4 = 0x00, Address (ZERO) 0x00, Address (NZERO)
(TBLATH = 0x00) (TBLATL = 0x00)
After Instruction
RAM TBLAT = = 0xB7 0x00B7 (TBLATH = 0x00) (TBLATL = 0xB7)
Before Instruction
t RAM TBLAT = = = 1 0xB7 0x0000
(TBLATH = 0x00) (TBLATL = 0x00)
After Instruction
RAM TBLAT = = 0xB7 0xB700 (TBLATH = 0xB7) (TBLATL = 0x00)
DS30289B-page 230
2000 Microchip Technology Inc.
PIC17C7XX
XORLW Syntax: Operands: Operation: Status Affected: Encoding: Description: Exclusive OR Literal with WREG [ label ] XORLW k 0 k 255 (WREG) .XOR. k (WREG) Z
1011 0100 kkkk kkkk
XORWF Syntax: Operands: Operation: Status Affected: Encoding: Description:
Exclusive OR WREG with f [ label ] XORWF 0 f 255 d [0,1] (WREG) .XOR. (f) (dest) Z
0000 110d ffff ffff
f,d
The contents of WREG are XOR'ed with the 8-bit literal 'k'. The result is placed in WREG.
Words: Cycles: Q Cycle Activity: Q1
Decode
1 1 Q2
Read literal 'k'
Exclusive OR the contents of WREG with register 'f'. If 'd' is 0, the result is stored in WREG. If 'd' is 1, the result is stored back in the register 'f'.
Words: Q3
Process Data
1 1 Q1
Decode
Q4
Write to WREG
Cycles: Q Cycle Activity:
Q2
Read register 'f'
Q3
Process Data
Q4
Write to destination
Example:
WREG WREG = =
XORLW
0xAF
Before Instruction
0xB5 0x1A
Example:
REG WREG REG WREG = = = =
XORWF
REG, 1 1010 1111 1011 0101 0001 1010
After Instruction
Before Instruction
0xAF 0xB5 0x1A 0xB5
After Instruction
2000 Microchip Technology Inc.
DS30289B-page 231
PIC17C7XX
NOTES:
DS30289B-page 232
2000 Microchip Technology Inc.
PIC17C7XX
19.0 DEVELOPMENT SUPPORT
The MPLAB IDE allows you to: * Edit your source files (either assembly or `C') * One touch assemble (or compile) and download to PICmicro emulator and simulator tools (automatically updates all project information) * Debug using: - source files - absolute listing file - machine code The ability to use MPLAB IDE with multiple debugging tools allows users to easily switch from the costeffective simulator to a full-featured emulator with minimal retraining. The PICmicro(R) microcontrollers are supported with a full range of hardware and software development tools: * Integrated Development Environment - MPLAB(R) IDE Software * Assemblers/Compilers/Linkers - MPASMTM Assembler - MPLAB C17 and MPLAB C18 C Compilers - MPLINKTM Object Linker/ MPLIBTM Object Librarian * Simulators - MPLAB SIM Software Simulator * Emulators - MPLAB ICE 2000 In-Circuit Emulator - ICEPICTM In-Circuit Emulator * In-Circuit Debugger - MPLAB ICD for PIC16F87X * Device Programmers - PRO MATE(R) II Universal Device Programmer - PICSTART(R) Plus Entry-Level Development Programmer * Low Cost Demonstration Boards - PICDEMTM 1 Demonstration Board - PICDEM 2 Demonstration Board - PICDEM 3 Demonstration Board - PICDEM 17 Demonstration Board - KEELOQ(R) Demonstration Board
19.2
MPASM Assembler
The MPASM assembler is a full-featured universal macro assembler for all PICmicro MCU's. The MPASM assembler has a command line interface and a Windows shell. It can be used as a stand-alone application on a Windows 3.x or greater system, or it can be used through MPLAB IDE. The MPASM assembler generates relocatable object files for the MPLINK object linker, Intel(R) standard HEX files, MAP files to detail memory usage and symbol reference, an absolute LST file that contains source lines and generated machine code, and a COD file 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.
19.1
MPLAB Integrated Development Environment Software
The MPLAB IDE software brings an ease of software development previously unseen in the 8-bit microcontroller market. The MPLAB IDE is a Windows(R)-based application that contains: * An interface to debugging tools - simulator - programmer (sold separately) - emulator (sold separately) - in-circuit debugger (sold separately) * A full-featured editor * A project manager * Customizable toolbar and key mapping * A status bar * On-line help
19.3
MPLAB C17 and MPLAB C18 C Compilers
The MPLAB C17 and MPLAB C18 Code Development Systems are complete ANSI `C' compilers for Microchip's PIC17CXXX and PIC18CXXX family of microcontrollers, respectively. These compilers provide powerful integration capabilities and ease of use not found with other compilers. For easier source level debugging, the compilers provide symbol information that is compatible with the MPLAB IDE memory display.
2000 Microchip Technology Inc.
DS30289B-page 233
PIC17C7XX
19.4 MPLINK Object Linker/ MPLIB Object Librarian 19.6 MPLAB ICE High Performance Universal In-Circuit Emulator with MPLAB IDE
The MPLINK object linker combines relocatable objects created by the MPASM assembler and the MPLAB C17 and MPLAB C18 C compilers. It can also link relocatable objects from pre-compiled libraries, using directives from a linker script. The MPLIB object librarian is a librarian for precompiled code to be used with the MPLINK object linker. When a routine from a library is called from another 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 MPLIB object librarian manages the creation and modification of library files. The MPLINK object linker features include: * Integration with MPASM assembler and MPLAB C17 and MPLAB C18 C compilers. * Allows all memory areas to be defined as sections to provide link-time flexibility. The MPLIB object librarian features include: * Easier linking because single libraries can be included instead of many smaller files. * Helps keep code maintainable by grouping related modules together. * Allows libraries to be created and modules to be added, listed, replaced, deleted or extracted.
The MPLAB ICE universal in-circuit emulator is intended to provide the product development engineer with a complete microcontroller design tool set for PICmicro microcontrollers (MCUs). Software control of the MPLAB ICE in-circuit emulator is provided by the MPLAB Integrated Development Environment (IDE), which allows editing, building, downloading and source debugging from a single environment. The MPLAB ICE 2000 is a full-featured emulator system with enhanced trace, trigger and data monitoring features. Interchangeable processor modules allow the system to be easily reconfigured for emulation of different processors. The universal architecture of the MPLAB ICE in-circuit emulator allows expansion to support new PICmicro microcontrollers. The MPLAB ICE in-circuit emulator system has been designed as a real-time emulation system, with advanced features that are generally found on more expensive development tools. The PC platform and Microsoft(R) Windows environment were chosen to best make these features available to you, the end user.
19.7
ICEPIC In-Circuit Emulator
19.5
MPLAB SIM Software Simulator
The MPLAB SIM software simulator allows code development in a PC-hosted environment by simulating the PICmicro series microcontrollers on an instruction level. On any given instruction, the data areas can be examined or modified and stimuli can be applied from a file, or user-defined key press, to any of the pins. The execution can be performed in single step, execute until break, or trace mode. The MPLAB SIM simulator fully supports symbolic debugging using the MPLAB C17 and the MPLAB C18 C compilers and the MPASM assembler. The software simulator offers the flexibility to develop and debug code outside of the laboratory environment, making it an excellent multiproject software development tool.
The ICEPIC low cost, in-circuit emulator is a solution for the Microchip Technology PIC16C5X, PIC16C6X, PIC16C7X and PIC16CXXX families of 8-bit OneTime-Programmable (OTP) microcontrollers. The modular system can support different subsets of PIC16C5X or PIC16CXXX products through the use of interchangeable personality modules, or daughter boards. The emulator is capable of emulating without target application circuitry being present.
DS30289B-page 234
2000 Microchip Technology Inc.
PIC17C7XX
19.8 MPLAB ICD In-Circuit Debugger
Microchip's In-Circuit Debugger, MPLAB ICD, is a powerful, low cost, run-time development tool. This tool is based on the FLASH PIC16F87X and can be used to develop for this and other PICmicro microcontrollers from the PIC16CXXX family. The MPLAB ICD utilizes the in-circuit debugging capability built into the PIC16F87X. This feature, along with Microchip's In-Circuit Serial ProgrammingTM protocol, offers costeffective in-circuit FLASH debugging from the graphical user interface of the MPLAB Integrated Development Environment. This enables a designer to develop and debug source code by watching variables, singlestepping and setting break points. Running at full speed enables testing hardware in real-time.
19.11 PICDEM 1 Low Cost PICmicro Demonstration Board
The PICDEM 1 demonstration board is a simple board which demonstrates the capabilities of several of Microchip's microcontrollers. The microcontrollers supported are: PIC16C5X (PIC16C54 to PIC16C58A), PIC16C61, PIC16C62X, PIC16C71, PIC16C8X, PIC17C42, PIC17C43 and PIC17C44. All necessary hardware and software is included to run basic demo programs. The user can program the sample microcontrollers provided with the PICDEM 1 demonstration board on a PRO MATE II device programmer, or a PICSTART Plus development programmer, and easily test firmware. The user can also connect the PICDEM 1 demonstration board to the MPLAB ICE incircuit emulator and download the firmware to the emulator for testing. A prototype area is available for the user to build some additional hardware and connect it to the microcontroller socket(s). Some of the features include an RS-232 interface, a potentiometer for simulated analog input, push button switches and eight LEDs connected to PORTB.
19.9
PRO MATE II Universal Device Programmer
The PRO MATE II universal device programmer is a full-featured programmer, capable of operating in stand-alone mode, as well as PC-hosted mode. The PRO MATE II device programmer is CE compliant. The PRO MATE II device programmer has programmable VDD and VPP supplies, which allow it to verify programmed memory at VDD min and VDD max for maximum reliability. It has an LCD display for instructions and error messages, keys to enter commands and a modular detachable socket assembly to support various package types. In stand-alone mode, the PRO MATE II device programmer can read, verify, or program PICmicro devices. It can also set code protection in this mode.
19.12 PICDEM 2 Low Cost PIC16CXX Demonstration Board
The PICDEM 2 demonstration board is a simple demonstration board that supports the PIC16C62, PIC16C64, PIC16C65, PIC16C73 and PIC16C74 microcontrollers. All the necessary hardware and software is included to run the basic demonstration programs. The user can program the sample microcontrollers provided with the PICDEM 2 demonstration board on a PRO MATE II device programmer, or a PICSTART Plus development programmer, and easily test firmware. The MPLAB ICE in-circuit emulator may also be used with the PICDEM 2 demonstration board to test firmware. A prototype area has been provided to the user for adding additional hardware and connecting it to the microcontroller socket(s). Some of the features include a RS-232 interface, push button switches, a potentiometer for simulated analog input, a serial EEPROM to demonstrate usage of the I2CTM bus and separate headers for connection to an LCD module and a keypad.
19.10 PICSTART Plus Entry Level Development Programmer
The PICSTART Plus development programmer is an easy-to-use, low cost, prototype programmer. It connects to the PC via a COM (RS-232) port. MPLAB Integrated Development Environment software makes using the programmer simple and efficient. The PICSTART Plus development programmer supports all PICmicro devices with up to 40 pins. Larger pin count devices, such as the PIC16C92X and PIC17C76X, may be supported with an adapter socket. The PICSTART Plus development programmer is CE compliant.
2000 Microchip Technology Inc.
DS30289B-page 235
PIC17C7XX
19.13 PICDEM 3 Low Cost PIC16CXXX Demonstration Board
The PICDEM 3 demonstration board is a simple demonstration board that supports the PIC16C923 and PIC16C924 in the PLCC package. It will also support future 44-pin PLCC microcontrollers with an LCD Module. All the necessary hardware and software is included to run the basic demonstration programs. The user can program the sample microcontrollers provided with the PICDEM 3 demonstration board on a PRO MATE II device programmer, or a PICSTART Plus development programmer with an adapter socket, and easily test firmware. The MPLAB ICE in-circuit emulator may also be used with the PICDEM 3 demonstration board to test firmware. A prototype area has been provided to the user for adding hardware and connecting it to the microcontroller socket(s). Some of the features include a RS-232 interface, push button switches, a potentiometer for simulated analog input, a thermistor and separate headers for connection to an external LCD module and a keypad. Also provided on the PICDEM 3 demonstration board is a LCD panel, with 4 commons and 12 segments, that is capable of displaying time, temperature and day of the week. The PICDEM 3 demonstration board provides an additional RS-232 interface and Windows software for showing the demultiplexed LCD signals on a PC. A simple serial interface allows the user to construct a hardware demultiplexer for the LCD signals.
19.14 PICDEM 17 Demonstration Board
The PICDEM 17 demonstration board is an evaluation board that demonstrates the capabilities of several Microchip microcontrollers, including PIC17C752, PIC17C756A, PIC17C762 and PIC17C766. All necessary hardware is included to run basic demo programs, which are supplied on a 3.5-inch disk. A programmed sample is included and the user may erase it and program it with the other sample programs using the PRO MATE II device programmer, or the PICSTART Plus development programmer, and easily debug and test the sample code. In addition, the PICDEM 17 demonstration board supports downloading of programs to and executing out of external FLASH memory on board. The PICDEM 17 demonstration board is also usable with the MPLAB ICE in-circuit emulator, or the PICMASTER emulator and all of the sample programs can be run and modified using either emulator. Additionally, a generous prototype area is available for user hardware.
19.15 KEELOQ Evaluation and Programming Tools
KEELOQ evaluation and programming tools support Microchip's HCS Secure Data Products. The HCS evaluation kit includes a LCD display to show changing codes, a decoder to decode transmissions and a programming interface to program test transmitters.
DS30289B-page 236
2000 Microchip Technology Inc.
24CXX/ 25CXX/ 93CXX
PIC14000
HCSXXX
PIC16C5X
PIC16C6X
PIC16C7X
PIC16C8X
PIC17C4X
PIC16F62X
PIC16C7XX
PIC16F8XX
PIC16C9XX
PIC17C7XX
PIC12CXXX
PIC16CXXX
PIC18CXX2
MCRFXXX
MCP2510
TABLE 19-1:
MPLAB(R) Integrated Development Environment
a
a
a
a
a
a
a
a
a
a
a
a
aa
aa
MPLAB(R) C17 C Compiler
Software Tools
MPLAB(R) C18 C Compiler
MPASMTM Assembler/ MPLINKTM Object Linker
a
a
Programmers Debugger Emulators
Demo Boards and Eval Kits
2000 Microchip Technology Inc.
aaa
aa
**
aa
aa
aa
aa
aa
aa
aa
aa
aa
aa
aa
aa
MPLAB(R) ICE In-Circuit Emulator
ICEPICTM In-Circuit Emulator
a
* *
a
a
a
a
a
a
a
MPLAB(R) ICD In-Circuit Debugger
a
**
a
a
PICSTART(R) Plus Entry Level Development Programmer
a
**
a
a
a
a
a
a
a
a
a
a
a
a
a
PRO MATE(R) II Universal Device Programmer
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
a
PICDEMTM 1 Demonstration Board
a

a
a
a
a
DEVELOPMENT TOOLS FROM MICROCHIP
PICDEMTM 2 Demonstration Board
a
a
a
PICDEMTM 3 Demonstration Board
a
PICDEMTM 14A Demonstration Board
a
PICDEMTM 17 Demonstration Board
a
KEELOQ(R) Evaluation Kit
aa
KEELOQ(R) Transponder Kit
microIDTM Programmer's Kit
aa
125 kHz microIDTM Developer's Kit
125 kHz Anticollision microIDTM Developer's Kit
a
13.56 MHz Anticollision microIDTM Developer's Kit
a
PIC17C7XX
DS30289B-page 237
MCP2510 CAN Developer's Kit
* Contact the Microchip Technology Inc. web site at www.microchip.com for information on how to use the MPLAB(R) ICD In-Circuit Debugger (DV164001) with PIC16C62, 63, 64, 65, 72, 73, 74, 76, 77. ** Contact Microchip Technology Inc. for availability date. Development tool is available on select devices.
a
PIC17C7XX
NOTES:
DS30289B-page 238
2000 Microchip Technology Inc.
PIC17C7XX
20.0 PIC17C7XX ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings Ambient temperature under bias.............................................................................................................-55C to +125C Storage temperature .............................................................................................................................. -65C to +150C Voltage on VDD with respect to VSS ........................................................................................................... 0 V to +7.5 V Voltage on MCLR with respect to VSS (Note 2) ....................................................................................... -0.3 V to +14 V Voltage on RA2 and RA3 with respect to VSS.......................................................................................... -0.3 V to +8.5 V Voltage on all other pins with respect to VSS ...................................................................................-0.3 V to VDD + 0.3 V Total power dissipation (Note 1) ..............................................................................................................................1.0 W Maximum current out of VSS pin(s) - total (@ 70C) ............................................................................................500 mA Maximum current into VDD pin(s) - total (@ 70C) ...............................................................................................500 mA Input clamp current, IIK (VI < 0 or VI > VDD) .......................................................................................................... 20 mA Output clamp current, IOK (VO < 0 or VO > VDD) ...................................................................................................20 mA Maximum output current sunk by any I/O pin (except RA2 and RA3).....................................................................35 mA Maximum output current sunk by RA2 or RA3 pins ................................................................................................60 mA Maximum output current sourced by any I/O pin ....................................................................................................20 mA Maximum current sunk by PORTA and PORTB (combined).................................................................................150 mA Maximum current sourced by PORTA and PORTB (combined) ...........................................................................100 mA Maximum current sunk by PORTC, PORTD and PORTE (combined)..................................................................150 mA Maximum current sourced by PORTC, PORTD and PORTE (combined) ............................................................100 mA Maximum current sunk by PORTF and PORTG (combined) ................................................................................150 mA Maximum current sourced by PORTF and PORTG (combined)...........................................................................100 mA Maximum current sunk by PORTH and PORTJ (combined).................................................................................150 mA Maximum current sourced by PORTH and PORTJ (combined) ...........................................................................100 mA Note 1: Power dissipation is calculated as follows: Pdis = VDD x {IDD - IOH} + {(VDD-VOH) x IOH} + (VOL x IOL) 2: Voltage spikes below VSS at the MCLR pin, inducing currents greater than 80 mA, may cause latch-up. Thus, a series resistor of 50-100 should be used when applying a "low" level to the MCLR pin, rather than pulling this pin directly to VSS.
NOTICE: Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability.
2000 Microchip Technology Inc.
DS30289B-page 239
PIC17C7XX
FIGURE 20-1: PIC17C7XX-33 VOLTAGE-FREQUENCY GRAPH 6.0 V 5.5 V 5.0 V PIC17C7XX-33
Voltage
4.5 V 4.0 V 3.5 V 3.0 V 2.5 V 2.0 V
33 MHz
Frequency
FIGURE 20-2:
PIC17C7XX-16 VOLTAGE-FREQUENCY GRAPH 6.0 V 5.5 V 5.0 V PIC17C7XX-16
Voltage
4.5 V 4.0 V 3.5 V 3.0 V 2.5 V 2.0 V
16 MHz
Frequency
DS30289B-page 240
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 20-3: PIC17LC7XX-08 VOLTAGE-FREQUENCY GRAPH 6.0 V 5.5 V 5.0 V
Voltage
4.5 V 4.0 V 3.5 V 3.0 V 2.5 V 2.0 V
PIC17LC7XX-08
8 MHz
Frequency
FIGURE 20-4:
PIC17C7XX/CL VOLTAGE-FREQUENCY GRAPH 6.0 V 5.5 V 5.0 V
PIC17C7XX/CL
Voltage
4.5 V 4.0 V 3.5 V 3.0 V 2.5 V 2.0 V
8 MHz
33 MHz
Frequency
2000 Microchip Technology Inc.
DS30289B-page 241
PIC17C7XX
20.1 DC Characteristics
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial and 0C TA +70C for commercial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +125C for extended -40C TA +85C for industrial 0C TA +70C for commercial Min Typ Max Units Conditions
PIC17LC7XX-08 (Commercial, Industrial) PIC17C7XX-16 (Commercial, Industrial, Extended) PIC17C7XX-33 (Commercial, Industrial, Extended) Param. No. D001 D001 D002 D003 VDR VPOR Sym VDD Characteristic Supply Voltage PIC17LC7XX
3.0
--
5.5 5.5 5.5 -- --
V V V V V (BOR enabled) (Note 5) Device in SLEEP mode See section on Power-on Reset for details
D004
SVDD
PIC17C7XX-33 4.5 -- PIC17C7XX-16 VBOR -- RAM Data Retention 1.5 -- Voltage (Note 1) VDD Start Voltage to -- Vss ensure internal Power-on Reset signal VDD Rise Rate to ensure proper operation PIC17LCXX 0.010 -- PIC17CXX 0.085 --
-- --
V/ms V/ms
D004 D005 VBOR
See section on Power-on Reset for details See section on Power-on Reset for details
Brown-out Reset 3.65 -- 4.35 V voltage trip point Power-on Reset trip -- 2.2 -- V VDD = VPORTP D006 VPORTP point Data in "Typ" column is at 5V, 25C unless otherwise stated. Note 1: This is the limit to which VDD can be lowered in SLEEP mode without losing RAM data. 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 pattern and temperature also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail to rail; all I/O pins tri-stated, pulled to VDD or VSS, T0CKI = VDD, MCLR = VDD; WDT disabled. Current consumed from the oscillator and I/O's driving external capacitive or resistive loads needs to be considered. For the RC oscillator, the current through the external pull-up resistor (R) can be estimated as: VDD/(2 * R). For capacitive loads, the current can be estimated (for an individual I/O pin) as (CL * VDD) * f CL = Total capacitive load on the I/O pin; f = average frequency the I/O pin switches. The capacitive currents are most significant when the device is configured for external execution (includes Extended Microcontroller mode). 3: 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 hi-impedance state and tied to VDD or VSS. 4: For RC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula IR = VDD/2REXT (mA) with REXT in kOhm. 5: This is the voltage where the device enters the Brown-out Reset. When BOR is enabled, the device (-16) will operate correctly to this trip point.
DS30289B-page 242
2000 Microchip Technology Inc.
PIC17C7XX
PIC17LC7XX-08 (Commercial, Industrial) PIC17C7XX-16 (Commercial, Industrial, Extended) PIC17C7XX-33 (Commercial, Industrial, Extended) Param. No. D010 D010 D011 D011 D012 D014 D015 D021 D021 (commercial, industrial) D021A (extended) D023 D024 D026
IBOR IWDT IAD
Sym IDD
Characteristic
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +85C for industrial and 0C TA +70C for commercial Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +125C for extended -40C TA +85C for industrial 0C TA +70C for commercial Min Typ Max Units Conditions
Supply Current (Note 2) PIC17LC7XX PIC17C7XX PIC17LC7XX PIC17C7XX PIC17LC7XX
-- -- -- -- -- --
3 3 5 5 9 85 15 <1 <1
6 6 10 10 18 150 30 5 20
mA mA mA mA mA A mA A A
IPD
PIC17C7XX -- Power-down Current (Note 3) PIC17LC7XX -- PIC17C7XX --
FOSC = 4 MHz (Note 4) FOSC = 4 MHz (Note 4) FOSC = 8 MHz FOSC = 8 MHz FOSC = 16 MHz FOSC = 32 kHz, (EC osc configuration) FOSC = 33 MHz VDD = 3.0V, WDT disabled VDD = 5.5V, WDT disabled
-- Module Differential Current BOR circuitry - Watchdog Timer A/D converter - -
2
20
A
VDD = 5.5V, WDT disabled
75 10 1
150 35 -
A A A
VDD = 4.5V, BODEN enabled VDD = 5.5V VDD = 5.5V, A/D not converting
Data in "Typ" column is at 5V, 25C unless otherwise stated. Note 1: This is the limit to which VDD can be lowered in SLEEP mode without losing RAM data. 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 pattern and temperature also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail to rail; all I/O pins tri-stated, pulled to VDD or VSS, T0CKI = VDD, MCLR = VDD; WDT disabled. Current consumed from the oscillator and I/O's driving external capacitive or resistive loads needs to be considered. For the RC oscillator, the current through the external pull-up resistor (R) can be estimated as: VDD/(2 * R). For capacitive loads, the current can be estimated (for an individual I/O pin) as (CL * VDD) * f CL = Total capacitive load on the I/O pin; f = average frequency the I/O pin switches. The capacitive currents are most significant when the device is configured for external execution (includes Extended Microcontroller mode). 3: 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 hi-impedance state and tied to VDD or VSS. 4: For RC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula IR = VDD/2REXT (mA) with REXT in kOhm. 5: This is the voltage where the device enters the Brown-out Reset. When BOR is enabled, the device (-16) will operate correctly to this trip point.
2000 Microchip Technology Inc.
DS30289B-page 243
PIC17C7XX
20.2 DC Characteristics: PIC17C7XX-16 (Commercial, Industrial, Extended) PIC17C7XX-33 (Commercial, Industrial, Extended) PIC17LC7XX-08 (Commercial, Industrial)
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +125C for extended -40C TA +85C for industrial 0C TA +70C for commercial Operating voltage VDD range as described in Section 20.1 Characteristic Input Low Voltage I/O ports with TTL buffer (Note 6) with Schmitt Trigger buffer RA2, RA3 All others MCLR, OSC1 (in EC and RC mode) OSC1 (in XT, and LF mode) Input High Voltage I/O ports with TTL buffer (Note 6) Min Typ Max Units Conditions
DC CHARACTERISTICS
Param. No.
Sym
VIL D030 D031
Vss Vss Vss Vss Vss -
- - - - - 0.5VDD
0.8 0.2VDD 0.3VDD 0.2VDD 0.2VDD -
V V V V V V
4.5V VDD 5.5V 3.0V VDD 4.5V I2C compliant (Note 1)
D032 D033 VIH D040 D041
2.0 1 + 0.2VDD
- -
VDD VDD
V V
4.5V VDD 5.5V 3.0V VDD 4.5V
D042 D043 D050
Note 1:
2: 3: 4:
5: 6:
with Schmitt Trigger buffer RA2, RA3 0.7VDD - VDD V I2C compliant All others 0.8VDD VDD - V 0.8VDD - VDD V (Note 1) MCLR OSC1 (XT, and LF mode) - 0.5VDD - V VHYS Hysteresis of 0.15VDD - - V Schmitt Trigger Inputs Data in "Typ" column is at 5V, 25C unless otherwise stated. In RC oscillator configuration, the OSC1/CLKIN pin is a Schmitt Trigger input. It is not recommended that the PIC17CXXX devices be driven with external clock in RC mode. The leakage current on the MCLR pin is strongly dependent on the applied voltage level. Higher leakage current may be measured at different input voltages. Negative current is defined as current sourced by the pin. These specifications are for the programming of the on-chip program memory EPROM through the use of the table write instructions. The complete programming specifications can be found in: PIC17C7XX Programming Specifications (Literature number DS TBD). The MCLR/VPP pin may be kept in this range at times other than programming, but is not recommended. For TTL buffers, the better of the two specifications may be used.
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PIC17C7XX
Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +125C for extended -40C TA +85C for industrial 0C TA +70C for commercial Operating voltage VDD range as described in Section 20.1 Characteristic Input Leakage Current (Notes 2, 3) I/O ports (except RA2, RA3) Min Typ Max Units Conditions
DC CHARACTERISTICS
Param. No.
Sym
D060
IIL
-
-
1
A
D061 D062 D063 D063B D064 D070 IPURB
MCLR, TEST RA2, RA3 OSC1 (EC, RC modes) OSC1 (XT, LF modes) MCLR, TEST PORTB Weak Pull-up Current Output Low Voltage
- - - - 85
- - - - 130
2 2 1 VPIN 25 260
A A A A A A
Vss VPIN VDD, I/O Pin (in digital mode) at hi-impedance PORTB weak pull-ups disabled VPIN = Vss or VPIN = VDD Vss VRA2, VRA3 12V Vss VPIN VDD RF 1 M VMCLR = VPP = 12V (when not programming) VPIN = VSS, RBPU = 0 4.5V VDD 5.5V IOL = VDD/1.250 mA 4.5V VDD 5.5V VDD = 3.0V IOL = 6 mA, VDD = 4.5V (Note 6) IOL = 60.0 mA, VDD = 5.5V IOL = 60.0 mA, VDD = 4.5V IOL = 1 mA, VDD = 4.5V IOL = VDD/5 mA (PIC17LC7XX only) IOH = -VDD/2.5 mA 4.5V VDD 5.5V VDD = 3.0V IOH = -6.0 mA, VDD = 4.5V (Note 6) IOH = -5 mA, VDD = 4.5V IOH = -VDD/5 mA (PIC17LC7XX only)
D080
VOL
I/O ports - - - - - - - - - - - - - - 0.1VDD 0.1VDD 0.4 3.0 0.6 0.4 0.1VDD V V V V V V V
D081 D082 D083 D084
with TTL buffer RA2 and RA3 OSC2/CLKOUT (RC and EC osc modes) Output High Voltage (Note 3) I/O ports (except RA2 and RA3)
D090
VOH
D091 D093 D094 with TTL buffer OSC2/CLKOUT (RC and EC osc modes)
0.9VDD 0.9VDD 2.4 2.4 0.9VDD
- - - - -
- - - - -
V V V V V
Data in "Typ" column is at 5V, 25C unless otherwise stated. Note 1: In RC oscillator configuration, the OSC1/CLKIN pin is a Schmitt Trigger input. It is not recommended that the PIC17CXXX devices be driven with external clock in RC mode. 2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. Higher leakage current may be measured at different input voltages. 3: Negative current is defined as current sourced by the pin. 4: These specifications are for the programming of the on-chip program memory EPROM through the use of the table write instructions. The complete programming specifications can be found in: PIC17C7XX Programming Specifications (Literature number DS TBD). 5: The MCLR/VPP pin may be kept in this range at times other than programming, but is not recommended. 6: For TTL buffers, the better of the two specifications may be used.
2000 Microchip Technology Inc.
DS30289B-page 245
PIC17C7XX
DC CHARACTERISTICS Standard Operating Conditions (unless otherwise stated) Operating temperature -40C TA +125C for extended -40C TA +85C for industrial 0C TA +70C for commercial Operating voltage VDD range as described in Section 20.1 Characteristic Open Drain High Voltage Min - Typ - Max 8.5 Units V Conditions RA2 and RA3 pins only pulled up to externally applied voltage
Param. No. D150
Sym VOD
D100
Capacitive Loading Specs on Output Pins COSC2 OSC2/CLKOUT pin
-
-
25
pF
In EC or RC osc modes, when OSC2 pin is outputting CLKOUT. External clock is used to drive OSC1.
D101 D102
CIO CAD
All I/O pins and OSC2 (in RC mode) System Interface Bus (PORTC, PORTD and PORTE)
- -
- -
50 50
pF pF In Microprocessor or Extended Microcontroller mode
D110 D111 D112 D113 D114
Internal Program Memory Programming Specs (Note 4) Voltage on MCLR/VPP pin VPP VDDP Supply voltage during programming IPP Current into MCLR/VPP pin IDDP Supply current during programming TPROG Programming pulse width
12.75 4.75 - - 100
- 5.0 25 - -
13.25 5.25 50 30 1000
V V mA mA ms
(Note 5)
Terminated via internal/ external interrupt or a RESET
Data in "Typ" column is at 5V, 25C unless otherwise stated. Note 1: In RC oscillator configuration, the OSC1/CLKIN pin is a Schmitt Trigger input. It is not recommended that the PIC17CXXX devices be driven with external clock in RC mode. 2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. Higher leakage current may be measured at different input voltages. 3: Negative current is defined as current sourced by the pin. 4: These specifications are for the programming of the on-chip program memory EPROM through the use of the table write instructions. The complete programming specifications can be found in: PIC17C7XX Programming Specifications (Literature number DS TBD). 5: The MCLR/VPP pin may be kept in this range at times other than programming, but is not recommended. 6: For TTL buffers, the better of the two specifications may be used.
Note 1: When using the Table Write for internal programming, the device temperature must be less than 40C. 2: For In-Circuit Serial Programming (ICSP), refer to the device programming specification.
DS30289B-page 246
2000 Microchip Technology Inc.
PIC17C7XX
20.3 Timing Parameter Symbology
The timing parameter symbols have been created following one of the following formats: 1. TppS2ppS 2. TppS T F Frequency Lowercase symbols (pp) and their meanings: pp ad Address/Data al ALE cc Capture1 and Capture2 ck CLKOUT or clock dt Data in in INT pin io I/O port mc MCLR oe OE os OSC1 Uppercase symbols and their meanings: S D Driven E Edge F Fall H High I Invalid (Hi-impedance) 3. TCC:ST 4. Ts T (I2C specifications only) (I2C specifications only) Time
ost pwrt rb rd rw t0 t123 wdt wr
Oscillator Start-Up Timer Power-Up Timer PORTB RD RD or WR T0CKI TCLK12 and TCLK3 Watchdog Timer WR
L P R V Z
Low Period Rise Valid Hi-impedance
2000 Microchip Technology Inc.
DS30289B-page 247
PIC17C7XX
FIGURE 20-5: PARAMETER MEASUREMENT INFORMATION
All timings are measured between high and low measurement points as indicated below.
INPUT LEVEL CONDITIONS
PORTC, D, E, F, G, H and J pins VIH = 2.4V VIL = 0.4V Data in valid All other input pins Data in invalid VIH = 0.9VDD VIL = 0.1VDD Data in valid Data in invalid
OUTPUT LEVEL CONDITIONS
0.25V VOH = 0.7VDD VDD/2 VOL = 0.3VDD Data out valid Data out invalid Output hi-impedance 0.9 VDD 0.1 VDD Rise Time Fall Time 0.25V 0.25V 0.25V Output driven
LOAD CONDITIONS
Load Condition 1
Pin CL
VSS
50 pF CL
DS30289B-page 248
2000 Microchip Technology Inc.
PIC17C7XX
20.4 Timing Diagrams and Specifications
EXTERNAL CLOCK TIMING
Q4 OSC1 1 2 OSC2 In EC and RC modes only. 3 3 4 Q1 Q2 Q3 Q4 Q1
FIGURE 20-6:
4
TABLE 20-1:
Param No. Sym FOSC
EXTERNAL CLOCK TIMING REQUIREMENTS
Characteristic External CLKIN Frequency (Note 1) Oscillator Frequency (Note 1) Min DC DC DC DC 2 2 2 DC 125 62.5 30.3 250 125 62.5 30.3 500 121.2 10 -- Typ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 4/FOSC -- -- Max 8 16 33 4 8 16 33 2 -- -- -- -- 1,000 1,000 1,000 -- DC -- 5 Units MHz MHz MHz MHz MHz MHz MHz MHz ns ns ns ns ns ns ns ns ns ns ns EC oscillator EC oscillator Conditions EC osc mode - 08 devices (8 MHz devices) - 16 devices (16 MHz devices) - 33 devices (33 MHz devices) RC osc mode XT osc mode - 08 devices (8 MHz devices) - 16 devices (16 MHz devices) - 33 devices (33 MHz devices) LF osc mode EC osc mode - 08 devices (8 MHz devices) - 16 devices (16 MHz devices) - 33 devices (33 MHz devices) RC osc mode XT osc mode - 08 devices (8 MHz devices) - 16 devices (16 MHz devices) - 33 devices (33 MHz devices) LF osc mode
1
TOSC
External CLKIN Period (Note 1) Oscillator Period (Note 1)
2 3 4
TCY TosL, TosH TosR, TosF
Instruction Cycle Time (Note 1) Clock in (OSC1) High or Low Time Clock in (OSC1) Rise or Fall Time
Data in "Typ" column is at 5V, 25C unless otherwise stated. Note 1: Instruction cycle period (TCY) 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 are tested to operate at "min." values with an external clock applied to the OSC1/CLKIN pin. When an external clock input is used, the "max." cycle time limit is "DC" (no clock) for all devices.
2000 Microchip Technology Inc.
DS30289B-page 249
PIC17C7XX
FIGURE 20-7: CLKOUT AND I/O TIMING
Q4 OSC1 10 OSC2 13 14 I/O Pin (input) 17 I/O Pin (output) Old Value 20, 21 In EC and RC modes only. 15 New Value 18 19 22 23 12 16 11 Q1 Q2 Q3
TABLE 20-2:
Param No. 10 11 12 13 14 15 16 17 18
CLKOUT AND I/O TIMING REQUIREMENTS
Sym Characteristic OSC1 to CLKOUT OSC1 to CLKOUT CLKOUT rise time CLKOUT fall time CLKOUT to Port out valid Port in valid before CLKOUT Port in hold after CLKOUT OSC1 (Q1 cycle) to Port out valid OSC1 (Q2 cycle) to Port input invalid (I/O in hold time) Port input valid to OSC1 (I/O in setup time) Port output rise time Port output fall time INT pin high or low time RB7:RB0 change INT high or low time Min -- -- -- -- -- 0.25TCY + 25 0 -- 0 Typ 15 15 5 5 -- -- -- -- -- Max 30 30 15 15 0.5TCY + 20 -- -- 100 -- Units ns ns ns ns ns ns ns ns ns Conditions (Note 1) (Note 1) (Note 1) (Note 1) (Note 1) (Note 1) (Note 1)
TosL2ckL TosL2ckH TckR TckF TckH2ioV TioV2ckH TckH2ioI TosL2ioV TosL2ioI
19 20 21 22 23
TioV2osL TioR TioF TinHL TrbHL
30 -- -- 25 25
-- 10 10 -- --
-- 35 35 -- --
ns ns ns ns ns
Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: Measurements are taken in EC mode, where CLKOUT output is 4 x TOSC.
DS30289B-page 250
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 20-8: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER, AND BROWN-OUT RESET TIMING
VDD MCLR 30 Internal POR/BOR 33 PWRT Time-out OSC Time-out Internal Reset Watchdog Timer Reset 35 Address/ Data 32
31
TABLE 20-3:
Param. No. 30 31 32 33 34 35
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER, AND BROWN-OUT RESET REQUIREMENTS
Sym Characteristic MCLR Pulse Width (low) Watchdog Timer Time-out Period (Postscale = 1) Oscillation Start-up Timer Period Power-up Timer Period MCLR to I/O hi-impedance PIC17C7XX PIC17LC7XX Min 100 5 -- 40 100 -- -- 100 Typ -- 12 1024TOSC 96 -- -- -- -- Max -- 25 -- 200 -- 100 120 -- Units ns ms ms ms ns ns ns ns VDD within VBOR limits (parameter D005) Conditions VDD = 5V VDD = 5V TOSC = OSC1 period VDD = 5V Depends on pin load
TmcL TWDT TOST TPWRT TIOZ
TmcL2adI MCLR to System Interface bus (AD15:AD0>) invalid TBOR
36 .
Brown-out Reset Pulse Width (low)
Data in "Typ" column is at 5V, 25C unless otherwise stated.
2000 Microchip Technology Inc.
DS30289B-page 251
PIC17C7XX
FIGURE 20-9:
RA1/T0CKI
TIMER0 EXTERNAL CLOCK TIMINGS
40
41
42
TABLE 20-4:
Param No. 40 41 42 Sym
TIMER0 EXTERNAL CLOCK REQUIREMENTS
Characteristic No Prescaler With Prescaler No Prescaler With Prescaler Min 0.5TCY + 20 10 0.5TCY + 20 10 Greater of: 20 ns or TCY + 40 N Typ -- -- -- -- -- Max -- -- -- -- -- Units ns ns ns ns ns N = prescale value (1, 2, 4, ..., 256) Conditions
Tt0H T0CKI High Pulse Width Tt0L Tt0P T0CKI Low Pulse Width T0CKI Period
Data in "Typ" column is at 5V, 25C unless otherwise stated.
FIGURE 20-10:
TCLK12 or TCLK3
TIMER1, TIMER2 AND TIMER3 EXTERNAL CLOCK TIMINGS
45
46
47 48 TMRx
48
TABLE 20-5:
Param No. 45 46 47 48
TIMER1, TIMER2 AND TIMER3 EXTERNAL CLOCK REQUIREMENTS
Characteristic TCLK12 and TCLK3 high time TCLK12 and TCLK3 low time TCLK12 and TCLK3 input period Delay from selected External Clock Edge to Timer increment Min 0.5TCY + 20 0.5TCY + 20 TCY + 40 N 2TOSC Typ -- -- -- -- Max -- -- -- 6Tosc Units ns ns ns -- N = prescale value (1, 2, 4, 8) Conditions
Sym Tt123H Tt123L Tt123P TckE2tmrI
Data in "Typ" column is at 5V, 25C unless otherwise stated.
DS30289B-page 252
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 20-11: CAPTURE TIMINGS
CAP pin (Capture mode)
50 52
51
TABLE 20-6:
Param No. 50 51 52 Sym TccL
CAPTURE REQUIREMENTS
Characteristic Capture pin input low time Min 10 10 2TCY N Typ -- -- -- Max -- -- -- Unit s ns ns ns N = prescale value (4 or 16) Conditions
TccH Capture pin input high time TccP Capture pin input period Data in "Typ" column is at 5V, 25C unless otherwise stated.
FIGURE 20-12:
PWM TIMINGS
PWM pin (PWM mode) 53 54
TABLE 20-7:
Param No. 53 54 Sym
PWM REQUIREMENTS
Characteristic Min -- -- Typ 10 10 Max 35 35 Units ns ns Conditions
TccR PWM pin output rise time TccF PWM pin output fall time Data in "Typ" column is at 5V, 25C unless otherwise stated.
2000 Microchip Technology Inc.
DS30289B-page 253
PIC17C7XX
FIGURE 20-13:
SS 70 SCK (CKP = 0) 71 72 78 SCK (CKP = 1) 79 78 79
SPI MASTER MODE TIMING (CKE = 0)
80 SDO MSb
75, 76
BIT6 - - - - - -1
LSb
SDI
MSb IN 74 73
BIT6 - - - -1
LSb IN
Note:
Refer to Figure 20-5 for load conditions.
TABLE 20-8:
Param. No. 70 71 71A 72 72A 73 73A 74 75 76 78 79 80 TscL
SPI MODE REQUIREMENTS (MASTER MODE, CKE = 0)
Characteristic SS to SCK or SCK input SCK input high time (Slave mode) SCK input low time (Slave mode) Continuous Single Byte Continuous Single Byte Min Tcy 1.25TCY + 30 40 1.25TCY + 30 40 100 1.5TCY + 40 100 -- -- -- -- -- Typ -- -- -- -- -- -- -- -- 10 10 10 10 -- Max -- -- -- -- -- -- -- -- 25 25 25 25 50 Units ns ns ns ns ns ns ns ns ns ns ns ns ns (Note 1) (Note 1) (Note 1) Conditions
Symbol TssL2scH, TssL2scL TscH
TdiV2scH, TdiV2scL TB2B TscH2diL, TscL2diL TdoR TdoF TscR TscF TscH2doV, TscL2doV
Setup time of SDI data input to SCK edge Last clock edge of Byte1 to the 1st clock edge of Byte2 Hold time of SDI data input to SCK edge SDO data output rise time SDO data output fall time SCK output rise time (Master mode) SCK output fall time (Master mode) SDO data output valid after SCK edge
Data in "Typ" column is at 5V, 25C unless otherwise stated. Note 1: Specification 73A is only required if specifications 71A and 72A are used.
DS30289B-page 254
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 20-14:
SS 81 SCK (CKP = 0) 71 73 SCK (CKP = 1) 80 78 72 79
SPI MASTER MODE TIMING (CKE = 1)
SDO
MSb 75, 76
BIT6 - - - - - -1
LSb
SDI
MSb IN 74 Note:
BIT6 - - - -1
LSb IN
Refer to Figure 20-5 for load conditions.
TABLE 20-9:
Param. No. 71 71A 72 72A 73 73A 74 75 76 78 79 80 81 TscL
SPI MODE REQUIREMENTS (MASTER MODE, CKE = 1)
Characteristic SCK input high time (Slave mode) SCK input low time (Slave mode) Continuous Single Byte Continuous Single Byte Min 1.25TCY + 30 40 1.25 TCY + 30 40 100 1.5TCY + 40 100 -- -- -- -- -- Tcy Typ -- -- -- -- -- -- -- 10 10 10 10 -- -- Max -- -- -- -- -- -- -- 25 25 25 25 50 -- Units ns ns ns ns ns ns ns ns ns ns ns ns ns (Note 1) (Note 1) (Note 1) Conditions
Symbol TscH
TdiV2scH, TdiV2scL TB2B TscH2diL, TscL2diL TdoR TdoF TscR TscF TscH2doV, TscL2doV TdoV2scH, TdoV2scL
Setup time of SDI data input to SCK edge Last clock edge of Byte1 to the 1st clock edge of Byte2 Hold time of SDI data input to SCK edge SDO data output rise time SDO data output fall time SCK output rise time (Master mode) SCK output fall time (Master mode) SDO data output valid after SCK edge SDO data output setup to SCK edge
Data in "Typ" column is at 5V, 25C unless otherwise stated. Note 1: Specification 73A is only required if specifications 71A and 72A are used.
2000 Microchip Technology Inc.
DS30289B-page 255
PIC17C7XX
FIGURE 20-15:
SS 70 SCK (CKP = 0) 71 72 83
SPI SLAVE MODE TIMING (CKE = 0)
78
79
SCK (CKP = 1) 79 78
80 SDO MSb 75, 76 SDI MSb IN 74 73 Note: Refer to Figure 20-5 for load conditions. BIT6 - - - -1
BIT6 - - - - - -1
LSb 77 LSb IN
TABLE 20-10: SPI MODE REQUIREMENTS (SLAVE MODE TIMING, CKE = 0)
Param. No. 70 71 71A 72 72A 73 73A 74 75 76 77 78 79 80 83 TdiV2scH, TdiV2scL TB2B TscH2diL, TscL2diL TdoR TdoF TssH2doZ TscR TscF TscH2doV, TscL2doV TscH2ssH, TscL2ssH TscL Symbol TssL2scH, TssL2scL TscH Characteristic SS to SCK or SCK input SCK input high time (Slave mode) SCK input low time (Slave mode) Continuous Single Byte Continuous Single Byte Min Tcy 1.25TCY + 30 40 1.25TCY + 30 40 100 1.5TCY + 40 100 -- -- 10 -- -- -- 1.5TCY + 40 Typ -- -- -- -- -- -- -- -- 10 10 -- 10 10 -- -- Max -- -- -- -- -- -- -- -- 25 25 50 25 25 50 -- Units ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns (Note 1) (Note 1) (Note 1) Conditions
Setup time of SDI data input to SCK edge Last clock edge of Byte1 to the 1st clock edge of Byte2 Hold time of SDI data input to SCK edge SDO data output rise time SDO data output fall time SS to SDO output hi-impedance SCK output rise time (Master mode) SCK output fall time (Master mode) SDO data output valid after SCK edge SS after SCK edge
Data in "Typ" column is at 5V, 25C unless otherwise stated.
Note 1: Specification 73A is only required if specifications 71A and 72A are used.
DS30289B-page 256
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 20-16: SPI SLAVE MODE TIMING (CKE = 1)
82 SS
SCK (CKP = 0)
70 83 71 72
SCK (CKP = 1) 80
SDO
MSb 75, 76
BIT6 - - - - - -1
LSb 77
SDI
MSb IN
BIT6 - - - -1
LSb IN
Note:
74 Refer to Figure 20-5 for load conditions.
TABLE 20-11: SPI MODE REQUIREMENTS (SLAVE MODE, CKE = 1)
Param. No. 70 71 71A 72 72A 73A 74 75 76 77 80 82 83 TB2B TscH2diL, TscL2diL TdoR TdoF TssH2doZ TscH2doV, TscL2doV TssL2doV TscH2ssH, TscL2ssH TscL Symbol TssL2scH, TssL2scL TscH Characteristic SS to SCK or SCK input SCK input high time (Slave mode) SCK input low time (Slave mode) Continuous Single Byte Continuous Single Byte Min Tcy 1.25TCY + 30 40 1.25TCY + 30 40 1.5TCY + 40 100 -- -- 10 -- -- 1.5TCY + 40 Typ -- -- -- -- -- -- -- 10 10 -- -- -- -- Max -- -- -- -- -- -- -- 25 25 50 50 50 -- Units ns ns ns ns ns ns ns ns ns ns ns ns ns (Note 1) (Note 1) (Note 1) Conditions
Last clock edge of Byte1 to the 1st clock edge of Byte2 Hold time of SDI data input to SCK edge SDO data output rise time SDO data output fall time SS to SDO output hi-impedance SDO data output valid after SCK edge SDO data output valid after SS edge SS after SCK edge
Data in "Typ" column is at 5V, 25C unless otherwise stated. Note 1: Specification 73A is only required if specifications 71A and 72A are used.
2000 Microchip Technology Inc.
DS30289B-page 257
PIC17C7XX
FIGURE 20-17: I2C BUS START/STOP BITS TIMING
SCL 90 SDA
91 92
93
START Condition Note: Refer to Figure 20-5 for load conditions.
STOP Condition
TABLE 20-12: I2C BUS START/STOP BITS REQUIREMENTS
Param. No. 90 Sym Tsu:sta Characteristic START condition Setup time 91 Thd:sta START condition Hold time 92 Tsu:sto STOP condition Setup time 93 Thd:sto STOP condition Hold time 100 kHz mode 400 kHz mode 1 MHz mode(1) 100 kHz mode 400 kHz mode 1 MHz mode(1) 100 kHz mode 400 kHz mode 1 MHz mode(1) 100 kHz mode 400 kHz mode 1 MHz mode(1) Note 1: Maximum pin capacitance = 10 pF for all I2C pins. Min 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) Ty p -- -- -- -- -- -- -- -- -- -- -- -- Max -- -- -- -- -- -- -- -- -- -- -- -- ns ns ns After this period, the first clock pulse is generated Units ns Conditions Only relevant for Repeated Start condition
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PIC17C7XX
FIGURE 20-18: I2C BUS DATA TIMING
103 SCL SDA In 109 SDA Out Note: Refer to Figure 20-5 for load conditions. 109 110 100 101 90 91 106 107 92 102
TABLE 20-13: I2C BUS DATA REQUIREMENTS
Param No. 100 Sym Thigh Characteristic Clock high time 100 kHz mode 400 kHz mode 1 MHz mode(1) 101 Tlow Clock low time 100 kHz mode 400 kHz mode 1 MHz mode(1) 102 Tr SDA and SCL rise time 100 kHz mode 400 kHz mode 1 MHz mode(1) 103 Tf SDA and SCL fall time 100 kHz mode 400 kHz mode 1 MHz mode(1) 90 Tsu:sta START condition setup time START condition hold time Data input hold time 100 kHz mode 400 kHz mode 1 MHz mode(1) 91 Thd:sta 100 kHz mode 400 kHz mode 1 MHz mode(1) 106 Thd:dat 100 kHz mode 400 kHz mode 1 MHz mode(1) 107 Tsu:dat Data input setup time 100 kHz mode 400 kHz mode 1 MHz mode(1) 92 Tsu:sto STOP condition setup time Output valid from clock 100 kHz mode 400 kHz mode 1 MHz mode(1) 109 Taa 100 kHz mode 400 kHz mode 1 MHz mode(1) Min 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) -- 20 + 0.1Cb -- -- 20 + 0.1Cb -- 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 0 0 0 250 100 100 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) 2(TOSC)(BRG + 1) -- -- -- Max -- -- -- -- -- -- 1000 300 300 300 300 10 -- -- -- -- -- -- -- 0.9 -- -- -- -- -- -- -- 3500 1000 400 Units ms ms ms ms ms ms ns ns ns ns ns ns ms ms ms ms ms ms ns ms ns ns ns ns ms ms ms ns ns ns (Note 2) After this period, the first clock pulse is generated Only relevant for Repeated Start condition Cb is specified to be from 10 to 400 pF Cb is specified to be from 10 to 400 pF Conditions
Note 1: Maximum pin capacitance = 10 pF for all I2C pins. 2: A fast mode (400 KHz) I2C bus device can be used in a standard mode I2C bus system, but the parameter # 107 250 ns must then be met. This will automatically be the case if the device does not stretch the LOW period of the 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. Parameter #102 + #107 = 1000 + 250 = 1250 ns (for 100 kHz mode) before the SCL line is released. 3: Cb is specified to be from 10-400pF. The minimum specifications are characterized with Cb=10pF. The rise time spec (tr) is characterized with Rp=Rp min. The minimum fall time specification (tf) is characterized with Cb=10pF,and Rp=Rp max. These are only valid for fast mode operation (VDD=4.5-5.5V) and where the SPM bit (SSPSTAT<7>) =1.) 4: Max specifications for these parameters are valid for falling edge only. Specs are characterized with Rp=Rp min and Cb=400pF for standard mode, 200pF for fast mode, and 10pF for 1MHz mode.
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PIC17C7XX
Param No. 110 Sym Tbuf Bus free time Characteristic 100 kHz mode 400 kHz mode 1 MHz mode(1) D102 Cb Bus capacitive loading Min 4.7 1.3 0.5 -- Max -- -- -- 400 Units ms ms ms pF Conditions Time the bus must be free before a new transmission can start
Note 1: Maximum pin capacitance = 10 pF for all I2C pins. 2: A fast mode (400 KHz) I2C bus device can be used in a standard mode I2C bus system, but the parameter # 107 250 ns must then be met. This will automatically be the case if the device does not stretch the LOW period of the 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. Parameter #102 + #107 = 1000 + 250 = 1250 ns (for 100 kHz mode) before the SCL line is released. 3: Cb is specified to be from 10-400pF. The minimum specifications are characterized with Cb=10pF. The rise time spec (tr) is characterized with Rp=Rp min. The minimum fall time specification (tf) is characterized with Cb=10pF,and Rp=Rp max. These are only valid for fast mode operation (VDD=4.5-5.5V) and where the SPM bit (SSPSTAT<7>) =1.) 4: Max specifications for these parameters are valid for falling edge only. Specs are characterized with Rp=Rp min and Cb=400pF for standard mode, 200pF for fast mode, and 10pF for 1MHz mode.
FIGURE 20-19:
TX/CK pin RX/DT pin
USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING
121
121
120
122
TABLE 20-14: USART SYNCHRONOUS TRANSMISSION REQUIREMENTS
Param No. 120 Sym TckH2dtV Characteristic SYNC XMIT (MASTER & SLAVE) Clock high to data out valid Clock out rise time and fall time (Master mode) Data out rise time and fall time Min Typ Max Units Conditions
PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX
-- -- -- -- -- --
-- -- -- -- -- --
50 75 25 40 25 40
ns ns ns ns ns ns
121 122
TckRF TdtRF
Data in "Typ" column is at 5V, 25C unless otherwise stated.
DS30289B-page 260
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PIC17C7XX
FIGURE 20-20:
TX/CK pin RX/DT pin 126
USART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING
125
TABLE 20-15: USART SYNCHRONOUS RECEIVE REQUIREMENTS
Param No. 125 126 Sym TdtV2ckL TckL2dtl Characteristic SYNC RCV (MASTER & SLAVE) Data setup before CK (DT setup time) Data hold after CK (DT hold time) Min Typ Max Unit s ns ns Conditions
15 15
-- --
-- --
Data in "Typ" column is at 5V, 25C unless otherwise stated.
2000 Microchip Technology Inc.
DS30289B-page 261
PIC17C7XX
FIGURE 20-21: USART ASYNCHRONOUS MODE START BIT DETECT
RX (RX/DT pin) 121A x16 CLK Q2, Q4 CLK 120A 123A START bit
TABLE 20-16: USART ASYNCHRONOUS MODE START BIT DETECT REQUIREMENTS
Param No. 120A 121A 123A Sym TdtL2ckH TdtRF TckH2bckL Characteristic Time to ensure that the RX pin is sampled low Data rise time and fall time Receive Transmit Time from RX pin sampled low to first rising edge of x16 clock Min -- -- -- -- Typ -- -- -- -- Max TCY (Note 1) 40 TCY Unit s ns ns ns ns Conditions
Note 1: Schmitt trigger will determine logic level.
FIGURE 20-22:
RX (RX/DT pin) Baud CLK x16 CLK
USART ASYNCHRONOUS RECEIVE SAMPLING WAVEFORM
START bit Baud CLK for all but START bit Bit0
1
2
3
4
5
6 125A
7
8
9
10 11 126A
12
13
14
15
16
1
2
3
Samples
TABLE 20-17: USART ASYNCHRONOUS RECEIVE SAMPLING REQUIREMENTS
Param No. 125A 126A Sym TdtL2ckH TdtL2ckH Characteristic Setup time of RX pin to first data sampled Hold time of RX pin from last data sampled Min TCY TCY Typ -- -- Max -- -- Unit s ns ns Conditions
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PIC17C7XX
TABLE 20-18: A/D CONVERTER CHARACTERISTICS
Param. No. A01 Sym NR Characteristic Resolution Min -- -- A02 EABS Absolute error -- -- A03 EIL Integral linearity error -- -- A04 EDL Differential linearity error -- -- A05 EFS Full scale error -- -- A06 EOFF Offset error -- -- A10 A20 A20A A21 A22 A25 A30 A40 A50 VREF+ VREFVAIN ZAIN IAD IREF Reference voltage high Reference voltage low Analog input voltage Recommended impedance of analog voltage source A/D conversion current (VDD) PIC17CXXX PIC17LCXXX -- VREF Monotonicity Reference voltage (VREF+ -- VREF-) -- 0V 3V AVSS + 3.0V Avss 0.3V AVSS 0.3V -- -- -- 10 Typ -- -- -- -- -- -- -- -- -- -- -- -- guaranteed(3) -- -- -- -- -- -- 180 90 -- Max 10 10 < 1 < 1 < 1 < 1 < 1 < 1 < 1 < 1 < 1 < 1 -- -- -- AVDD + 0.3V AVDD 3.0V Vref + 0.3V 10.0 -- -- 1000 Units bit bit LSb LSb LSb LSb LSb LSb LSb LSb LSb LSb -- V V V V V k A A A Average current consumption when A/D is on (Note 1) During VAIN acquisition. Based on differential of VHOLD to VAIN During A/D conversion cycle Conditions VREF+ = VDD = 5.12V, VSS VAIN VREF+ (VREF+ -- VREF-) 3.0V, VREF- VAIN VREF+ VREF+ = VDD = 5.12V, VSS VAIN VREF+ (VREF+ -- VREF-) 3.0V, VREF- VAIN VREF+ VREF+ = VDD = 5.12V, VSS VAIN VREF+ (VREF+ -- VREF-) 3.0V, VREF- VAIN VREF+ VREF+ = VDD = 5.12V, VSS VAIN VREF+ (VREF+ -- VREF-) 3.0V, VREF- VAIN VREF+ VREF+ = VDD = 5.12V, VSS VAIN VREF+ (VREF+ -- VREF-) 3.0V, VREF- VAIN VREF+ VREF+ = VDD = 5.12V, VSS VAIN VREF+ (VREF+ -- VREF-) 3.0V, VREF- VAIN VREF+ VSS VAIN VREF VREF delta when changing voltage levels on VREF inputs Absolute minimum electrical spec. to ensure 10-bit accuracy
VREF input current (Note 2)
--
--
10
A
Data in "Typ" column is at 5V, 25C unless otherwise stated. Note 1: When A/D is off, it will not consume any current other than minor leakage current. The power-down current spec includes any such leakage from the A/D module. 2: VREF current is from RG0 and RG1 pins or AVDD and AVSS pins, whichever is selected as reference input. 3: The A/D conversion result never decreases with an increase in the Input Voltage and has no missing codes.
2000 Microchip Technology Inc.
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PIC17C7XX
FIGURE 20-23: A/D CONVERSION TIMING
1 TCY (TOSC/2)(1) Q4 130 A/D CLK A/D DATA ADRES ADIF GO DONE SAMPLING STOPPED 132 9 8 7 ... ... 2 1 0 NEW_DATA 131
BSF ADCON0, GO
OLD_DATA
SAMPLE
Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the SLEEP instruction to be executed.
TABLE 20-19: A/D CONVERSION REQUIREMENTS
Param. No. 130 Sym TAD Characteristic A/D clock period PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX 131 132 TCNV TACQ Conversion time (not including acquisition time) (Note 1) Acquisition time Min 1.6 3.0 2.0 3.0 11 (Note 2) 10 Typ -- -- 4.0 6.0 -- 20 -- Max -- -- 6.0 9.0 12 -- -- Units s s s s Tad s s The minimum time is the amplifier settling time. This may be used if the "new" input voltage has not changed by more than 1LSb (i.e., 5 mV @ 5.12V) from the last sampled voltage (as stated on CHOLD). If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts. This allows the SLEEP instruction to be executed. Conditions TOSC based, VREF 3.0V TOSC based, VREF full range A/D RC mode A/D RC mode
134
TGO
Q4 to ADCLK start
--
Tosc/2
--
--
Data in "Typ" column is at 5V, 25C unless otherwise stated. Note 1: ADRES register may be read on the following TCY cycle. 2: See Section 16.1 for minimum conditions when input voltage has changed more than 1 LSb.
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2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 20-24: MEMORY INTERFACE WRITE TIMING
Q1 Q2 Q3 Q4
Q1
Q2
OSC1
ALE
OE WR 150 AD<15:0> addr out
151
154 data out 152 153 addr out
TABLE 20-20: MEMORY INTERFACE WRITE REQUIREMENTS
Param. No. 150 Sym TadV2alL Characteristic AD<15:0> (address) valid to ALE (address setup time) 151 152 153 154 TalL2adI TadV2wrL TwrH2adI TwrL (address hold time) Data out valid to WR (data setup time) WR to data out invalid (data hold time) WR pulse width PIC17CXXX PIC17LCXXX Min 0.25TCY - 10 0.25TCY - 10 0 0 0.25TCY - 40 0.25TCY - 40 -- -- -- -- Typ -- -- -- -- -- -- 0.25TCY 0.25TCY 0.25TCY 0.25TCY Max -- -- -- -- -- -- -- -- -- -- ns ns ns ns Unit s ns Conditions
ALE to address out invalid PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX
Data in "Typ" column is at 5V, 25C unless otherwise stated.
2000 Microchip Technology Inc.
DS30289B-page 265
PIC17C7XX
FIGURE 20-25: MEMORY INTERFACE READ TIMING
Q1 Q2 Q3 Q4 Q1 Q2
OSC1 166 ALE OE 164 168 160 165 AD<15:0> Addr out 150 WR '1' 167 151 Data in 162 163
'1'
161 Addr out
TABLE 20-21: MEMORY INTERFACE READ REQUIREMENTS
Param. No. 150 151 160 161 Sym TadV2alL TalL2adI TadZ2oeL ToeH2ad D TadV2oeH Characteristic AD15:AD0 (address) valid to ALE (address setup time) ALE to address out invalid (address hold time) AD15:AD0 hi-impedance to OE OE to AD15:AD0 driven PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX Data in valid before OE (data setup time) 163 164 165 166 167 168 ToeH2adI TalH ToeL TalH2alH Tacc Toe OEto data in invalid (data hold time) ALE pulse width OE pulse width ALE to ALE(cycle time) Address access time Output enable access time (OE low to data valid) PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX PIC17CXXX PIC17LCXXX Min 0.25TCY - 10 0.25TCY - 10 5 5 0 0 0.25TCY - 15 0.25TCY - 15 35 45 0 0 -- -- 0.5TCY - 35 0.5TCY - 35 -- -- -- -- -- -- Typ -- -- -- -- -- -- -- -- -- -- -- -- 0.25TCY 0.25TCY -- -- TCY TCY -- -- -- -- Max -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 0.75TCY - 30 0.75TCY - 45 0.5TCY - 45 0.5TCY - 75 ns ns ns ns ns ns ns ns ns ns Unit s ns Conditions
162
Data in "Typ" column is at 5V, 25C unless otherwise stated.
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2000 Microchip Technology Inc.
PIC17C7XX
21.0 PIC17C7XX DC AND AC CHARACTERISTICS
The graphs and tables provided in this section are for design guidance and are not tested nor guaranteed. In some graphs or tables the data presented is outside specified operating range (e.g., outside specified VDD range). This is for information only and devices are ensured to operate properly only within the specified range. The data presented in this section is a statistical summary of data collected on units from different lots over a period of time. * Typ or Typical represents the mean of the distribution at 25C. * Max or Maximum represents (mean + 3) over the temperature range of -40C to 85C. * Min or Minimum represents (mean - 3) over the temperature range of -40C to 85C. Note: Standard deviation is denoted by sigma ().
TABLE 21-1:
PIN CAPACITANCE PER PACKAGE TYPE
Typical Capacitance (pF) Pin Name 68-pin PLCC 64-pin TQFP 10 20
All pins, except MCLR, VDD, and VSS MCLR pin
10 20
FIGURE 21-1:
Fosc Fosc (25C) 1.10 1.08 1.06 1.04 1.02 1.00
TYPICAL RC OSCILLATOR FREQUENCY vs. TEMPERATURE
Frequency normalized to +25C
REXT 10 k CEXT = 100 pF
VDD = 5.5V 0.98 0.96 0.94 VDD = 3.5V 0.92 0.90 0 10 20 25 30 T(C) 40 50 60 70
2000 Microchip Technology Inc.
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PIC17C7XX
FIGURE 21-2:
4.0 3.5 3.0 FOSC (MHz) 2.5 2.0 1.5 CEXT = 22 pF, T = +25C 1.0 0.5 0.0 4.0 4.5 5.0 VDD (Volts) R = 100k 5.5 6.0 6.5 R = 10k
TYPICAL RC OSCILLATOR FREQUENCY vs. VDD
FIGURE 21-3:
4.0 3.5 3.0 FOSC (MHz) 2.5 2.0 1.5 1.0
TYPICAL RC OSCILLATOR FREQUENCY vs. VDD
R = 3.3k
R = 5.1k
R = 10k CEXT = 100 pF, T = +25C R = 100k 4.0 4.5 5.0 VDD (Volts) 5.5 6.0 6.5
0.5 0.0
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PIC17C7XX
FIGURE 21-4:
2.0 1.8 1.6 1.4 1.2 FOSC (MHz) R = 5.1k 1.0 0.8 0.6 0.4 CEXT = 300 pF, T = +25C 0.2 0.0 4.0 4.5 5.0 VDD (Volts) R = 160k 5.5 6.0 6.5 R = 10k R = 3.3k
TYPICAL RC OSCILLATOR FREQUENCY vs. VDD
TABLE 21-2:
CEXT 22 pF
RC OSCILLATOR FREQUENCIES
REXT 10k 100k 3.3k 5.1k 10k 100k 3.3k 5.1k 10k 160k 3.33 MHz 353 kHz 3.54 MHz 2.43 MHz 1.30 MHz 129 kHz 1.54 MHz 980 kHz 564 kHz 35 kHz Average FOSC @ 5V, +25C 12% 13% 10% 14% 17% 10% 14% 12% 16% 18%
100 pF
300 pF
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PIC17C7XX
FIGURE 21-5:
500 450 400 350 Max @ -40C 300 gm(A/V) Typ @ +25C 250 200 150 Min @ +85C 100 50 0 2.5 3.0 3.5 4.0 VDD (Volts) 4.5 5.0 5.5 6.0
TRANSCONDUCTANCE (gm) OF LF OSCILLATOR vs. VDD
FIGURE 21-6:
20 18
TRANSCONDUCTANCE (gm) OF XT OSCILLATOR vs. VDD
Max @ -40C 16 14 Typ @ +25C 12 gm(mA/V) 10 8 6 Min @ +85C 4 2 0 2.5 3.0 3.5 4.0 VDD (Volts) 4.5 5.0 5.5 6.0
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PIC17C7XX
FIGURE 21-7: TYPICAL IDD vs. FOSC OVER VDD (LF MODE)
1.2
1.0
Typical: statistical mean @ 25C Maximum: mean + 3s (-40C to 125C) Minimum: mean - 3s (-40C to 125C)
5.5V
0.8 5.0V IDD (mA) 4.5V 0.6 4.0V 3.5V 0.4 3.0V
0.2
0.0 0.0 0.2 0.4 0.6 0.8 1.0 FOSC (M Hz) 1.2 1.4 1.6 1.8 2.0
FIGURE 21-8:
MAXIMUM IDD vs. FOSC OVER VDD (LF MODE)
1.2
1.0
Typical: statistical mean @ 25C Maximum: mean + 3s (-40C to 125C) Minimum: mean - 3s (-40C to 125C)
5.5V
5.0V 0.8 4.5V IDD (mA) 4.0V 0.6 3.5V 3.0V 0.4
0.2
0.0 0.0 0.2 0.4 0.6 0.8 1.0 FOSC (M Hz ) 1.2 1.4 1.6 1.8 2.0
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PIC17C7XX
FIGURE 21-9: TYPICAL IDD vs. FOSC OVER VDD (XT MODE)
16 5.5V 14
Ty pic al: s tatis tic al mean @ @ Typical: statistical mean25C25C Max imum: Maximum: mean + 3 (-40C to 125C)125C) mean + 3s (-40C to Minimum: mean - 3 (-40C to 125C) Minimum: mean - 3s (-40C to 125C)
5.0V
12 4.5V
10 IDD (mA)
8
6
4 4.0V 3.5V 2 3.0V
0 0 5 10 15 FOSC(M Hz ) 20 25 30 35
FIGURE 21-10:
MAXIMUM IDD vs. FOSC OVER VDD (XT MODE)
18
Typic al: statistical mean @ Typical: statis tical mean @ 25C 25C Max imum: mean + 3s (-40C to Maximum: mean + 3 (-40C to 125C) 125C) Minimum: Minimum: mean - 3-(-40C to 125C) 125C) mean 3s (-40C to
5.5V
16
5.0V
14 4.5V 12
IDD (mA)
10
8
6
4 4.0V 3.5V 2 3.0V
0 0 5 10 15 FOSC (M Hz) 20 25 30 35
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PIC17C7XX
FIGURE 21-11: TYPICAL AND MAXIMUM IPD vs. VDD (SLEEP MODE, ALL PERIPHERALS DISABLED, -40C to +125C)
6.0
5.0
Typical: statistical mean @ 25C Maximum: mean + 3s (-40C to 125C) Minimum: mean - 3s (-40C to 125C)
M ax
4.0
IPD (uA)
3.0
2.0 Typ 1.0
0.0 3.0 3.5 4.0 V DD (V ) 4.5 5.0 5.5
FIGURE 21-12:
TYPICAL AND MAXIMUM IPD vs. VDD (SLEEP MODE, BOR ENABLED, -40C to +125C)
2.0
1.8
1.6
Typical: statistical mean @ 25C Maximum: mean + 3s (-40C to 125C) Minimum: mean - 3s (-40C to 125C)
1.4
1.2 IDD (mA) M ax Res et 1.0
0.8 Ty p Reset (25C) 0.6 Indeterm inate S tate 0.4 Devic e in Res et 0.2 Max S leep Ty p S leep (25C) 0.0 3.0 3.5 4.0 V DD (V ) 4.5 5.0 5.5 Devic e in S leep
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PIC17C7XX
FIGURE 21-13: TYPICAL AND MAXIMUM IPD vs. VDD (SLEEP MODE, WDT ENABLED, -40C to +125C)
18
16
14
12 M ax IPD (uA) 10 Ty p 8
6
4
2
0 3.0 3.5 4.0 V DD (V ) 4.5 5.0 5.5
FIGURE 21-14:
TYPICAL AND MAXIMUM IRBPU vs. VDD (MEASURED PER INPUT PIN, -40C TO +125C)
300
250
Typical: s tatis tic al mean @ 25C 25C Ty pic al: statistical mean @ Max imum: mean + 3 (-40C to 125C) Maximum: mean + 3s (-40C to 125C) Minimum: Minimum:mean - 3 (-40C(-40C to 125C) mean - 3s to 125C)
M ax im um
200
I (uA)
150 Typical (25C) 100
50
0 2.5 3.0 3.5 4.0 V DD (V ) 4.5 5.0 5.5
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PIC17C7XX
FIGURE 21-15: TYPICAL, MINIMUM AND MAXIMUM WDT PERIOD vs. VDD (-40C TO +125C)
40
35
Ty pic statistical mean @ 25C Typical: al: s tatis tic almean@ 25C Max imum: mean + Maximum: mean + 3 (-40C to 125C) 3s (-40C to 125C) Minimum: mean - 3 (-40C to 125C) Minimum: mean - 3s (-40C to 125C)
30 M ax (125C) 25 WDT Period (ms)
20
15 Typ (25C) 10
M in (-40C) 5
0 3.0 3.5 4.0 V DD (V ) 4.5 5.0 5.5
FIGURE 21-16:
30
TYPICAL WDT PERIOD vs. VDD OVER TEMPERATURE (-40C TO +125C)
25
20 125C WDT Period (ms) 85C 15
25C 10 -40C
5
0 3.0 3.5 4.0 VDD (V) 4.5 5.0 5.5
2000 Microchip Technology Inc.
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PIC17C7XX
FIGURE 21-17: TYPICAL, MINIMUM AND MAXIMUM VOH vs. IOH (VDD = 5V, -40C TO +125C)
5.0
4.5 Max 4.0 Ty p (25C) 3.5
3.0 VOH (V)
2.5 M in 2.0
1.5
1.0
Typical: statistical mean @ 25C Maximum: mean + 3s (-40C to 125C) Minimum: mean - 3s (-40C to 125C)
0.5
0.0 0 5 10 IOH (-m A) 15 20 25
FIGURE 21-18:
TYPICAL, MINIMUM AND MAXIMUM VOL vs. IOL (VDD = 5V, -40C TO +125C)
1 .6
1 .4
Typical:y pstatisticalamean @ 25C T ic a l: s ta tis tic l m e a n @ 2 5 C M a x im m : m e a + 3s 4 0 C to 1 5 C Maximum: umeann + 3 ( - (-40C2 to )125C) M in im u m : m e a n - 3 ( - 4 0 C to 1 2 5 C ) Minimum: mean - 3s (-40C to 125C)
M ax (12 5C )
1 .2
1 .0
VOL (V)
0 .8 T yp (2 5 C ) 0 .6 M in ( - 4 0 C ) 0 .4
0 .2
0 .0 0 5 10 IO L ( m A ) 15 20 25
DS30289B-page 276
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 21-19: TYPICAL, MINIMUM AND MAXIMUM VOH vs. IOH (VDD = 3V, -40C TO +125C)
3.0
2.5
Typical: statistical mean @ 25C Maximum: mean + 3s (-40C to 125C) Minimum: mean - 3s (-40C to 125C)
2.0
VOH (V)
1.5 M in M ax
1.0 Ty p (25C)
0.5
0.0 0 5 10 IOH (-m A) 15 20 25
FIGURE 21-20:
TYPICAL, MINIMUM AND MAXIMUM VOL vs. IOL (VDD = 3V, -40C TO +125C)
2 .0
1 .8
1 .6
Typical: statistical mean @ to 125C) 25C Max imum: mean + 3 (-40C Maximum: mean-+ (-(- 40C to 125C) Minimum: mean 3 3s 40C to 125C) Minimum: mean - 3s (-40C to 125C)
Ty pic al: s tatis tic al mean @ 25C
1 .4
1 .2 Ma x (1 2 5 C )
VOL (V)
1 .0
0 .8
0 .6 Typ (2 5 C ) 0 .4 Min (-4 0 C ) 0 .2
0 .0 0 5 10 15 20 25
IOL (m A)
2000 Microchip Technology Inc.
DS30289B-page 277
PIC17C7XX
FIGURE 21-21: TYPICAL, MAXIMUM AND MINIMUM VIN vs. VDD (TTL INPUT, -40C to 125C)
1.8
1.6 Max 1.4 Ty p (25C) Min 1.2
VIN (V)
1.0
0.8
0.6
0.4
Typical: statistical mean @ 25C Maximum: mean + 3s (-40C to 125C) Minimum: mean - 3s (-40C to 125C)
0.2
0.0 3.0 3.5 4.0 V DD (V ) 4.5 5.0 5.5
FIGURE 21-22:
MAXIMUM AND MINIMUM VIN vs. VDD (ST Input, -40 C to +125C)
3 .5 Ma x R is in g
3 .0
Typical: statistical mean @ 25C Maximum: mean + 3s (-40C to 125C) Minimum: mean - 3s (-40C to 125C)
Min R is in g
2 .5 Ma x Fa llin g 2 .0 VIN (V) 1 .5
Min Fa llin g 1 .0
0 .5
0 .0 3 .0 3 .5 4 .0 V DD (V ) 4 .5 5 .0 5 .5
DS30289B-page 278
2000 Microchip Technology Inc.
PIC17C7XX
FIGURE 21-23: MAXIMUM AND MINIMUM VIN vs. VDD (I2C Input, -40C to +125C)
4 .0
3 .5
Typical: statistical mean @ 25C Maximum: mean + 3s (-40C to 125C) Minimum: mean - 3s (-40C to 125C)
Ma x R is in g
3 .0 Min R is in g 2 .5
VIN (V)
2 .0
Ma x Fa llin g Min Fa llin g
1 .5
1 .0
0 .5
0 .0 3 .0 3 .5 4 .0 V DD (V ) 4 .5 5 .0 5 .5
2000 Microchip Technology Inc.
DS30289B-page 279
PIC17C7XX
NOTES:
DS30289B-page 280
2000 Microchip Technology Inc.
PIC17C7XX
22.0
22.1
PACKAGING INFORMATION
Package Marking Information
64-Lead TQFP Example
XXXXXXXXXX XXXXXXXXXX XXXXXXXXXX YYWWNNN
PIC17C752 -08I/PT 0017CAE
68-Lead PLCC
Example
XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX YYWWNNN
PIC17C756A-08/L
0048CAE
80-Lead TQFP
Example
XXXXXXXXXXXX XXXXXXXXXXXX YYWWNNN
PIC17C762 -08I/PT 0017CAE
Legend:
XX...X YY WW NNN
Customer specific information* Year code (last 2 digits of calendar year) Week code (week of January 1 is week `01') Alphanumeric traceability code
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.
*
Standard OTP marking consists of Microchip part number, year code, week code, facility code, mask rev#, and assembly code. For OTP 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.
2000 Microchip Technology Inc.
DS30289B-page 281
PIC17C7XX
Package Marking Information (Cont.)
84-Lead PLCC
Example
XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXX YYWWNNN
PIC17C766-08/L
0048CAE
DS30289B-page 282
2000 Microchip Technology Inc.
PIC17C7XX
64-Lead Plastic Thin Quad Flatpack (PT) 10x10x1 mm Body, 1.0/0.10 mm Lead Form (TQFP)
E E1 #leads=n1 p
D1
D
2 1 B n CH x 45 A c
L
A1 (F)
A2
Number of Pins Pitch Pins per Side Overall Height Molded Package Thickness Standoff Foot Length Footprint (Reference) Foot Angle Overall Width Overall Length Molded Package Width Molded Package Length Lead Thickness Lead Width Pin 1 Corner Chamfer Mold Draft Angle Top Mold Draft Angle Bottom * Controlling Parameter Significant Characteristic
Units Dimension Limits n p n1 A A2 A1 L (F) E D E1 D1 c B CH
MIN
.039 .037 .002 .018 0 .463 .463 .390 .390 .005 .007 .025 5 5
INCHES NOM 64 .020 16 .043 .039 .006 .024 .039 3.5 .472 .472 .394 .394 .007 .009 .035 10 10
MAX
MIN
.047 .041 .010 .030 7 .482 .482 .398 .398 .009 .011 .045 15 15
MILLIMETERS* NOM 64 0.50 16 1.00 1.10 0.95 1.00 0.05 0.15 0.45 0.60 1.00 0 3.5 11.75 12.00 11.75 12.00 9.90 10.00 9.90 10.00 0.13 0.18 0.17 0.22 0.64 0.89 5 10 5 10
MAX
1.20 1.05 0.25 0.75 7 12.25 12.25 10.10 10.10 0.23 0.27 1.14 15 15
Notes: Dimensions D1 and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MS-026 Drawing No. C04-085
2000 Microchip Technology Inc.
DS30289B-page 283
PIC17C7XX
68-Lead Plastic Leaded Chip Carrier (L) - Square (PLCC)
E E1 #leads=n1
D1 D
CH2 x 45
n 12
CH1 x 45 A2 A
A3
32 c
B1
E2 Units Dimension Limits n p INCHES* NOM 68 .050 17 .173 .153 .028 .029 .045 .005 .990 .990 .954 .954 .920 .920 .011 .029 .020 5 5
B D2
p
A1
MIN
MAX
MIN
Number of Pins Pitch Pins per Side n1 Overall Height A .165 .180 .145 .160 Molded Package Thickness A2 .035 Standoff A1 .020 Side 1 Chamfer Height A3 .024 .034 Corner Chamfer 1 CH1 .040 .050 Corner Chamfer (others) CH2 .000 .010 Overall Width E .985 .995 Overall Length D .985 .995 Molded Package Width E1 .950 .958 Molded Package Length D1 .950 .958 Footprint Width E2 .890 .930 Footprint Length D2 .890 .930 c Lead Thickness .008 .013 Upper Lead Width B1 .026 .032 Lower Lead Width B .013 .021 0 10 Mold Draft Angle Top Mold Draft Angle Bottom 0 10 * Controlling Parameter Significant Characteristic Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MO-047 Drawing No. C04-049
MILLIMETERS NOM 68 1.27 17 4.19 4.39 3.68 3.87 0.71 0.51 0.61 0.74 1.02 1.14 0.00 0.13 25.02 25.15 25.02 25.15 24.13 24.23 24.13 24.23 22.61 23.37 22.61 23.37 0.20 0.27 0.66 0.74 0.33 0.51 0 5 0 5
MAX
4.57 4.06 0.89 0.86 1.27 0.25 25.27 25.27 24.33 24.33 23.62 23.62 0.33 0.81 0.53 10 10
DS30289B-page 284
2000 Microchip Technology Inc.
PIC17C7XX
80-Lead Plastic Thin Quad Flatpack (PT) 12x12x1 mm Body, 1.0/0.10 mm Lead Form (TQFP)
E E1 #leads=n1 p
D1
D
B
2 1
n
CH x 45 A
c
L A1 (F) Units Dimension Limits n p n1 A A2 A1 L (F) E D E1 D1 c B CH INCHES NOM 80 .020 20 .043 .039 .004 .024 .039 3.5 .551 .551 .472 .472 .006 .009 .035 10 10 MILLIMETERS* NOM 80 0.50 20 1.00 1.10 0.95 1.00 0.05 0.10 0.45 0.60 1.00 0 3.5 13.75 14.00 13.75 14.00 11.75 12.00 11.75 12.00 0.09 0.15 0.17 0.22 0.64 0.89 5 10 5 10
A2
MIN
MAX
MIN
MAX
Number of Pins Pitch Pins per Side Overall Height Molded Package Thickness Standoff Foot Length Footprint (Reference) Foot Angle Overall Width Overall Length Molded Package Width Molded Package Length Lead Thickness Lead Width Pin 1 Corner Chamfer Mold Draft Angle Top Mold Draft Angle Bottom * Controlling Parameter Significant Characteristic
.039 .037 .002 .018 0 .541 .541 .463 .463 .004 .007 .025 5 5
.047 .041 .006 .030 7 .561 .561 .482 .482 .008 .011 .045 15 15
1.20 1.05 0.15 0.75 7 14.25 14.25 12.25 12.25 0.20 0.27 1.14 15 15
Notes: Dimensions D1 and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MS-026 Drawing No. C04-092
2000 Microchip Technology Inc.
DS30289B-page 285
PIC17C7XX
84-Lead Plastic Leaded Chip Carrier (L) - Square (PLCC)
E E1 #leads=n1
D1 D
n 12 CH2 x 45
CH1 x 45 A2 A
A3
32 c
B1
E2 Units Dimension Limits n p INCHES* NOM 68 .050 17 .165 .173 .145 .153 .028 .020 .024 .029 .040 .045 .000 .005 .985 .990 .985 .990 .950 .954 .950 .954 .890 .920 .890 .920 .008 .011 .026 .029 .013 .020 0 5 0 5
B D2
p
A1
MIN
MAX
MIN
Number of Pins Pitch Pins per Side n1 Overall Height A .180 .160 Molded Package Thickness A2 .035 Standoff A1 Side 1 Chamfer Height A3 .034 Corner Chamfer 1 CH1 .050 Corner Chamfer (others) CH2 .010 Overall Width E .995 Overall Length D .995 Molded Package Width E1 .958 Molded Package Length D1 .958 Footprint Width E2 .930 Footprint Length D2 .930 c Lead Thickness .013 Upper Lead Width B1 .032 Lower Lead Width B .021 Mold Draft Angle Top 10 Mold Draft Angle Bottom 10 * Controlling Parameter Significant Characteristic Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MO-047 Drawing No. C04-093
MILLIMETERS NOM 68 1.27 17 4.19 4.39 3.68 3.87 0.71 0.51 0.61 0.74 1.02 1.14 0.00 0.13 25.02 25.15 25.02 25.15 24.13 24.23 24.13 24.23 22.61 23.37 22.61 23.37 0.20 0.27 0.66 0.74 0.33 0.51 0 5 0 5
MAX
4.57 4.06 0.89 0.86 1.27 0.25 25.27 25.27 24.33 24.33 23.62 23.62 0.33 0.81 0.53 10 10
DS30289B-page 286
2000 Microchip Technology Inc.
PIC17C7XX
APPENDIX A: MODIFICATIONS APPENDIX B: COMPATIBILITY
The following is the list of modifications over the PIC16CXX microcontroller family: 1. Instruction word length is increased to 16-bit. This allows larger page sizes, both in program memory (8 Kwords verses 2 Kwords) and register file (256 bytes versus 128 bytes). Four modes of operation: Microcontroller, Protected Microcontroller, Extended Microcontroller, and Microprocessor. 22 new instructions. The MOVF, TRIS and OPTION instructions are no longer supported. Four new instructions (TLRD, TLWT, TABLRD, TABLWT) for transferring data between data memory and program memory. They can be used to "self program" the EPROM program memory. Single cycle data memory to data memory transfers possible (MOVPF and MOVFP instructions). These instructions do not affect the Working register (WREG). W register (WREG) is now directly addressable. A PC high latch register (PCLATH) is extended to 8-bits. The PCLATCH register is now both readable and writable. Data memory paging is redefined slightly. DDR registers replace function of TRIS registers. Multiple Interrupt vectors added. This can decrease the latency for servicing interrupts. Stack size is increased to 16 deep. BSR register for data memory paging. Wake-up from SLEEP operates slightly differently. The Oscillator Start-Up Timer (OST) and PowerUp Timer (PWRT) operate in parallel and not in series. PORTB interrupt-on-change feature works on all eight port pins. TMR0 is 16-bit, plus 8-bit prescaler. Second indirect addressing register added (FSR1 and FSR2). Control bits can select the FSR registers to auto-increment, auto-decrement, remain unchanged after an indirect address. Hardware multiplier added (8 x 8 16-bit). Peripheral modules operate slightly differently. A/D has both VREF+ and VREF- inputs. USARTs do not implement BRGH feature. Oscillator modes slightly redefined. Control/Status bits and registers have been placed in different registers and the control bit for globally enabling interrupts has inverse polarity. In-circuit serial programming is implemented differently. To convert code written for PIC16CXXX to PIC17CXXX, the user should take the following steps: 1. 2. 3. Remove any TRIS and OPTION instructions, and implement the equivalent code. Separate the Interrupt Service Routine into its four vectors. Replace: MOVF REG1, W with: MOVFP REG1, WREG Replace: MOVF REG1, W MOVWF REG2 with: MOVPF REG1, REG2 ; Addr(REG1)<20h or MOVFP REG1, REG2 ; Addr(REG2)<20h Note:
2.
3.
4.
4.
5.
6. 7.
8. 9. 10. 11. 12. 13. 14.
If REG1 and REG2 are both at addresses greater then 20h, two instructions are required. MOVFP REG1, WREG ; MOVPF WREG, REG2 ; 5. Ensure that all bit names and register names are updated to new data memory map locations. 6. Verify data memory banking. 7. Verify mode of operation for indirect addressing. 8. Verify peripheral routines for compatibility. 9. Weak pull-ups are enabled on RESET. 10. WDT time-outs always reset the device (in run or SLEEP mode).
B.1
Upgrading from PIC17C42 Devices
To convert code from the PIC17C42 to all the other PIC17CXXX devices, the user should take the following steps. 1. If the hardware multiply is to be used, ensure that any variables at address 18h and 19h are moved to another address. Ensure that the upper nibble of the BSR was not written with a non-zero value. This may cause unexpected operation since the RAM bank is no longer 0. The disabling of global interrupts has been enhanced, so there is no additional testing of the GLINTD bit after a BSF CPUSTA, GLINTD instruction.
15. 16. 17.
2.
3.
18. 19. 20. 21. 22. 23.
24.
2000 Microchip Technology Inc.
DS30289B-page 287
PIC17C7XX
APPENDIX C:
* * * * PIC17C752 PIC17C756A PIC17C762 PIC17C766
WHAT'S NEW
APPENDIX D:
WHAT'S CHANGED
This is a new Data Sheet for the Following Devices:
Clarified the TAD vs. device maximum operating frequency tables in Section 16.2. Added device characteristic graphs and charts in Section 21. Removed the "Preliminary" status from the entire document.
This Data Sheet is based on the PIC17C75X Data Sheet (DS30246A).
DS30289B-page 288
2000 Microchip Technology Inc.
PIC17C7XX
INDEX
A
A/D Accuracy/Error .......................................................... 189 ADCON0 Register..................................................... 179 ADCON1 Register..................................................... 180 ADIF bit ..................................................................... 181 Analog Input Model Block Diagram........................... 184 Analog-to-Digital Converter....................................... 179 Block Diagram........................................................... 181 Configuring Analog Port Pins.................................... 186 Configuring the Interrupt ........................................... 181 Configuring the Module............................................. 181 Connection Considerations....................................... 189 Conversion Clock...................................................... 185 Conversions .............................................................. 186 Converter Characteristics ......................................... 263 Delays ....................................................................... 183 Effects of a RESET ................................................... 188 Equations .................................................................. 183 Flow Chart of A/D Operation..................................... 187 GO/DONE bit ............................................................ 181 Internal Sampling Switch (Rss) Impedence .............. 183 Operation During SLEEP .......................................... 188 Sampling Requirements............................................ 183 Sampling Time .......................................................... 183 Source Impedence.................................................... 183 Time Delays .............................................................. 183 Transfer Function...................................................... 189 A/D Interrupt........................................................................ 38 A/D Interrupt Flag bit, ADIF................................................. 38 A/D Module Interrupt Enable, ADIE .................................... 36 ACK................................................................................... 144 Acknowledge Data bit, AKD .............................................. 136 Acknowledge Pulse........................................................... 144 Acknowledge Sequence Enable bit, AKE ......................... 136 Acknowledge Status bit, AKS ........................................... 136 ADCON0 ............................................................................. 49 ADCON1 ............................................................................. 49 ADDLW ............................................................................. 202 ADDWF ............................................................................. 202 ADDWFC .......................................................................... 203 ADIE.................................................................................... 36 ADIF .................................................................................... 38 ADRES Register ............................................................... 179 ADRESH ............................................................................. 49 ADRESL.............................................................................. 49 AKD................................................................................... 136 AKE ................................................................................... 136 AKS ........................................................................... 136, 159 ALU ..................................................................................... 11 ALUSTA ............................................................................ 198 ALUSTA Register................................................................ 51 ANDLW ............................................................................. 203 ANDWF ............................................................................. 204 Application Note AN552, 'Implementing Wake-up on Keystroke.' ..................................................................... 74 Application Note AN578, "Use of the SSP Module in the I2C Multi-Master Environment."............................... 143 Assembler MPASM Assembler................................................... 233 Asynchronous Master Transmission ................................. 123 Asynchronous Transmitter ................................................ 123
B
Bank Select Register (BSR) ............................................... 57 Banking......................................................................... 46, 57 Baud Rate Formula........................................................... 120 Baud Rate Generator ....................................................... 153 Baud Rate Generator (BRG) ............................................ 120 Baud Rates Asynchronous Mode................................................. 122 Synchronous Mode................................................... 121 BCF .................................................................................. 204 BCLIE ................................................................................. 36 BCLIF ................................................................................. 38 BF ............................................................. 134, 144, 159, 162 Bit Manipulation ................................................................ 198 Block Diagrams A/D............................................................................ 181 Analog Input Model................................................... 184 Baud Rate Generator ............................................... 153 BSR Operation ........................................................... 57 External Brown-out Protection Circuit (Case1)........... 31 External Power-on Reset Circuit ................................ 24 External Program Memory Connection ...................... 45 I2C Master Mode ...................................................... 151 I2C Module................................................................ 143 Indirect Addressing..................................................... 54 On-chip Reset Circuit ................................................. 23 PORTD ....................................................................... 80 PORTE ........................................................... 82, 90, 91 Program Counter Operation ....................................... 56 PWM......................................................................... 107 RA0 and RA1.............................................................. 72 RA2............................................................................. 72 RA3............................................................................. 73 RA4 and RA5.............................................................. 73 RB3:RB2 Port Pins ..................................................... 75 RB7:RB4 and RB1:RB0 Port Pins .............................. 74 RC7:RC0 Port Pins..................................................... 78 SSP (I2C Mode)........................................................ 143 SSP (SPI Mode) ....................................................... 137 SSP Module (I2C Master Mode) ............................... 133 SSP Module (I2C Slave Mode) ................................. 133 SSP Module (SPI Mode) .......................................... 133 Timer3 with One Capture and One Period Register. 110 TMR1 and TMR2 in 16-bit Timer/Counter Mode ...... 105 TMR1 and TMR2 in Two 8-bit Timer/Counter Mode 104 TMR3 with Two Capture Registers........................... 112 Using CALL, GOTO.................................................... 56 WDT ......................................................................... 193 BODEN ............................................................................... 31 Borrow ................................................................................ 11 BRG .......................................................................... 120, 153 Brown-out Protection .......................................................... 31 Brown-out Reset (BOR)...................................................... 31 BSF................................................................................... 205 BSR .................................................................................... 57 BSR Operation ................................................................... 57 BTFSC .............................................................................. 205 BTFSS .............................................................................. 206 BTG .................................................................................. 206 Buffer Full bit, BF .............................................................. 144 Buffer Full Status bit, BF................................................... 134 Bus Arbitration .................................................................. 170 Bus Collision Section...................................................................... 170
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PIC17C7XX
Bus Collision During a RESTART Condition..................... 173 Bus Collision During a START Condition.......................... 171 Bus Collision During a STOP Condition............................ 174 Bus Collision Interrupt Enable, BCLIE ................................ 36 Bus Collision Interrupt Flag bit, BCLIF ................................ 38 Configuration Bits............................................................................ 192 Locations .................................................................. 192 Oscillator............................................................. 17, 192 Word ......................................................................... 191 CPFSEQ ........................................................................... 209 CPFSGT ........................................................................... 209 CPFSLT ............................................................................ 210 CPUSTA ..................................................................... 52, 194 Crystal Operation, Overtone Crystals ................................. 18 Crystal or Ceramic Resonator Operation............................ 18 Crystal Oscillator................................................................. 17
C
C.................................................................................... 11, 51 CA1/PR3 ........................................................................... 102 CA1ED0 ............................................................................ 101 CA1ED1 ............................................................................ 101 CA1IE.................................................................................. 35 CA1IF .................................................................................. 37 CA1OVF............................................................................ 102 CA2ED0 ............................................................................ 101 CA2ED1 ............................................................................ 101 CA2H............................................................................. 28, 49 CA2IE.......................................................................... 35, 111 CA2IF .......................................................................... 37, 111 CA2L ............................................................................. 28, 49 CA2OVF............................................................................ 102 CA3H................................................................................... 50 CA3IE.................................................................................. 36 CA3IF .................................................................................. 38 CA3L ................................................................................... 50 CA4H................................................................................... 50 CA4IE.................................................................................. 36 CA4IF .................................................................................. 38 Calculating Baud Rate Error ............................................. 120 CALL ........................................................................... 54, 207 Capacitor Selection Ceramic Resonators ................................................... 18 Crystal Oscillator ......................................................... 18 Capture ..................................................................... 101, 110 Capture Sequence to Read Example................................ 113 Capture1 Mode ......................................................................... 101 Overflow ............................................................ 102, 103 Capture1 Interrupt ............................................................... 37 Capture2 Mode ......................................................................... 101 Overflow ............................................................ 102, 103 Capture2 Interrupt ............................................................... 37 Capture3 Interrupt Enable, CA3IE ...................................... 36 Capture3 Interrupt Flag bit, CA3IF ...................................... 38 Capture4 Interrupt Enable, CA4IE ...................................... 36 Capture4 Interrupt Flag bit, CA4IF ...................................... 38 Carry (C) ............................................................................. 11 Ceramic Resonators ........................................................... 17 Circular Buffer ..................................................................... 54 CKE................................................................................... 134 CKP................................................................................... 135 Clearing the Prescaler....................................................... 193 Clock Polarity Select bit, CKP ........................................... 135 Clock/Instruction Cycle (Figure) .......................................... 21 Clocking Scheme/Instruction Cycle..................................... 21 CLRF................................................................................. 207 CLRWDT........................................................................... 208 Code Examples Indirect Addressing ..................................................... 55 Loading the SSPBUF register ................................... 138 Saving Status and WREG in RAM .............................. 42 Table Read ................................................................. 64 Table Write.................................................................. 62 Code Protection ................................................................ 195 COMF................................................................................ 208
D
D/A.................................................................................... 134 Data Memory GPR ...................................................................... 43, 46 Indirect Addressing ..................................................... 54 Organization ............................................................... 46 SFR ............................................................................ 43 Data Memory Banking ........................................................ 46 Data/Address bit, D/A ....................................................... 134 DAW ................................................................................. 210 DC................................................................................. 11, 51 DDRB...................................................................... 27, 48, 74 DDRC ..................................................................... 28, 48, 78 DDRD ..................................................................... 28, 48, 80 DDRE...................................................................... 28, 48, 82 DDRF .................................................................................. 49 DDRG ................................................................................. 49 DECF ................................................................................ 211 DECFSNZ......................................................................... 212 DECFSZ ........................................................................... 211 Delay From External Clock Edge........................................ 98 Digit Borrow ........................................................................ 11 Digit Carry (DC) .................................................................. 11 Duty Cycle ........................................................................ 107
E
Electrical Characteristics PIC17C752/756 Absolute Maximum Ratings .............................. 239 Capture Timing ................................................. 253 CLKOUT and I/O Timing .................................. 250 DC Characteristics............................................ 242 External Clock Timing....................................... 249 Memory Interface Read Timing ........................ 266 Memory Interface Write Timing ........................ 265 Parameter Measurement Information............... 248 Reset, Watchdog Timer, Oscillator Start-up Timer and Power-up Timer Timing ................... 251 Timer0 Clock Timing......................................... 252 Timer1, Timer2 and Timer3 Clock Timing ........ 252 Timing Parameter Symbology .......................... 247 USART Module Synchronous Receive Timing. 261 USART Module Synchronous Transmission Timing............................................................... 260 EPROM Memory Access Time Order Suffix....................... 45 Errata .................................................................................... 5 Extended Microcontroller .................................................... 43 Extended Microcontroller Mode .......................................... 45 External Memory Interface.................................................. 45 External Program Memory Waveforms............................... 45
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2000 Microchip Technology Inc.
PIC17C7XX
F
Family of Devices PIC17C75X ................................................................... 8 FERR ................................................................................ 125 Flowcharts Acknowledge............................................................. 166 Master Receiver........................................................ 163 Master Transmit ........................................................ 160 RESTART Condition ................................................. 157 Start Condition .......................................................... 155 STOP Condition ........................................................ 168 FOSC0 .............................................................................. 191 FOSC1 .............................................................................. 191 FS0 ..................................................................................... 51 FS1 ..................................................................................... 51 FS2 ..................................................................................... 51 FS3 ..................................................................................... 51 FSR0 ................................................................................... 54 FSR1 ................................................................................... 54 Bus Collision............................................................. 170 Acknowledge .................................................... 170 RESTART Condition......................................... 173 RESTART Condition Timing (Case1) ............... 173 RESTART Condition Timing (Case2) ............... 173 START Condition.............................................. 171 START Condition Timing.......................... 171, 172 STOP Condition................................................ 174 STOP Condition Timing (Case1) ...................... 174 STOP Condition Timing (Case2) ...................... 174 Transmit Timing................................................ 170 Bus Collision Timing ................................................. 170 Clock Arbitration ....................................................... 169 Clock Arbitration Timing (Master Transmit) .............. 169 Conditions to not give ACK Pulse............................. 144 General Call Address Support .................................. 149 Master Mode............................................................. 151 Master Mode 7-bit Reception timing ......................... 164 Master Mode Operation............................................ 152 Master Mode Start Condition.................................... 154 Master Mode Transmission ...................................... 159 Master Mode Transmit Sequence ............................ 152 Master Transmit Flowchart ....................................... 160 Multi-Master Communication.................................... 170 Multi-master Mode.................................................... 152 Operation.................................................................. 143 Repeat Start Condition timing................................... 156 RESTART Condition Flowchart ................................ 157 Slave Mode............................................................... 144 Slave Reception ....................................................... 145 Slave Transmission .................................................. 146 SSPBUF ................................................................... 144 Start Condition Flowchart ......................................... 155 Stop Condition Flowchart ......................................... 168 Stop Condition Receive or Transmit timing .............. 167 Stop Condition timing ............................................... 167 Waveforms for 7-bit Reception ................................. 146 Waveforms for 7-bit Transmission............................ 146 I2C Module Address Register, SSPADD .......................... 144 I2C Slave Mode ................................................................ 144 INCF ................................................................................. 213 INCFSNZ .......................................................................... 214 INCFSZ............................................................................. 213 In-Circuit Serial Programming........................................... 196 INDF0 ................................................................................. 54 INDF1 ................................................................................. 54 Indirect Addressing Indirect Addressing..................................................... 54 Operation.................................................................... 55 Registers .................................................................... 54 Initializing PORTB............................................................... 75 Initializing PORTC .............................................................. 78 Initializing PORTD .............................................................. 80 Initializing PORTE................................................... 82, 84, 86 INSTA ................................................................................. 48 Instruction Flow/Pipelining .................................................. 21 Instruction Set ADDLW..................................................................... 202 ADDWF .................................................................... 202 ADDWFC.................................................................. 203 ANDLW..................................................................... 203 ANDWF .................................................................... 204 BCF .......................................................................... 204 BSF........................................................................... 205 BTFSC...................................................................... 205 BTFSS ...................................................................... 206
G
GCE .................................................................................. 136 General Call Address Sequence....................................... 149 General Call Address Support .......................................... 149 General Call Enable bit, GCE ........................................... 136 General Format for Instructions ........................................ 198 General Purpose RAM ........................................................ 43 General Purpose RAM Bank............................................... 57 General Purpose Register (GPR) ....................................... 46 GLINTD ......................................................... 39, 52, 111, 194 Global Interrupt Disable bit, GLINTD .................................. 39 GOTO ............................................................................... 212 GPR (General Purpose Register) ....................................... 46 GPR Banks ......................................................................... 57 Graphs RC Oscillator Frequency vs. VDD (CEXT = 100 pF)... 268 RC Oscillator Frequency vs. VDD (CEXT = 22 pF)..... 268 RC Oscillator Frequency vs. VDD (CEXT = 300 pF)... 269 Transconductance of LF Oscillator vs.VDD ............... 270 Transconductance of XT Oscillator vs. VDD.............. 270 Typical RC Oscillator vs. Temperature ..................... 267
H
Hardware Multiplier ............................................................. 67
I
I/O Ports Bi-directional ............................................................... 93 I/O Ports...................................................................... 71 Programming Considerations ..................................... 93 Read-Modify-Write Instructions................................... 93 Successive Operations ............................................... 94 I2C ..................................................................................... 143 I2C Input ........................................................................... 279 I2C Master Mode Receiver Flow Chart ............................. 163 I2C Master Mode Reception.............................................. 162 I2C Master Mode RESTART Condition ............................. 156 I2C Mode Selection ........................................................... 143 I2C Module Acknowledge Flow Chart .......................................... 166 Acknowledge Sequence Timing................................ 165 Addressing ................................................................ 145 Baud Rate Generator................................................ 153 Block Diagram........................................................... 151 BRG Block Diagram.................................................. 153 BRG Reset due to SDA Collision.............................. 172 BRG Timing .............................................................. 153 Bus Arbitration .......................................................... 170
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BTG........................................................................... 206 CALL ......................................................................... 207 CLRF......................................................................... 207 CLRWDT................................................................... 208 COMF ....................................................................... 208 CPFSEQ ................................................................... 209 CPFSGT ................................................................... 209 CPFSLT .................................................................... 210 DAW.......................................................................... 210 DECF ........................................................................ 211 DECFSNZ ................................................................. 212 DECFSZ.................................................................... 211 GOTO ....................................................................... 212 INCF.......................................................................... 213 INCFSNZ .................................................................. 214 INCFSZ ..................................................................... 213 IORLW ...................................................................... 214 IORWF ...................................................................... 215 LCALL ....................................................................... 215 MOVFP ..................................................................... 216 MOVLB ..................................................................... 216 MOVLR ..................................................................... 217 MOVLW .................................................................... 217 MOVPF ..................................................................... 218 MOVWF .................................................................... 218 MULLW ..................................................................... 219 MULWF ..................................................................... 219 NEGW ....................................................................... 220 NOP .......................................................................... 220 RETFIE ..................................................................... 221 RETLW ..................................................................... 221 RETURN ................................................................... 222 RLCF......................................................................... 222 RLNCF ...................................................................... 223 RRCF ........................................................................ 223 RRNCF ..................................................................... 224 SETF ......................................................................... 224 SLEEP ...................................................................... 225 SUBLW ..................................................................... 225 SUBWF ..................................................................... 226 SUBWFB................................................................... 226 SWAPF ..................................................................... 227 TABLRD ............................................................ 227, 228 TABLWT ........................................................... 228, 229 TLRD......................................................................... 229 TLWT ........................................................................ 230 TSTFSZ .................................................................... 230 XORLW ..................................................................... 231 XORWF..................................................................... 231 Instruction Set Summary................................................... 197 Instructions TABLRD ...................................................................... 64 TLRD........................................................................... 64 INT Pin ................................................................................ 40 INTE .................................................................................... 34 INTEDG......................................................................... 53, 97 Inter-Integrated Circuit (I2C).............................................. 133 Internal Sampling Switch (Rss) Impedence ...................... 183 Interrupt on Change Feature............................................... 74 Interrupt Status Register (INTSTA) ..................................... 34 Interrupts A/D Interrupt................................................................ 38 Bus Collision Interrupt ................................................. 38 Capture1 Interrupt ....................................................... 37 Capture2 Interrupt ....................................................... 37 Capture3 Interrupt ....................................................... 38 Capture4 Interrupt ...................................................... 38 Context Saving ........................................................... 39 Flag bits TMR1IE .............................................................. 33 TMR1IF............................................................... 33 TMR2IE .............................................................. 33 TMR2IF............................................................... 33 TMR3IE .............................................................. 33 TMR3IF............................................................... 33 Global Interrupt Disable .............................................. 39 Interrupts .................................................................... 33 Logic ........................................................................... 33 Operation .................................................................... 39 Peripheral Interrupt Enable......................................... 35 Peripheral Interrupt Request....................................... 37 PIE2 Register ............................................................. 36 PIR1 Register ............................................................. 37 PIR2 Register ............................................................. 38 PORTB Interrupt on Change ...................................... 37 PWM ......................................................................... 108 RA0/INT ...................................................................... 39 Status Register ........................................................... 34 Synchronous Serial Port Interrupt............................... 38 T0CKI Interrupt ........................................................... 39 Timing ......................................................................... 40 TMR1 Overflow Interrupt ............................................ 37 TMR2 Overflow Interrupt ............................................ 37 TMR3 Overflow Interrupt ............................................ 37 USART1 Receive Interrupt ......................................... 37 USART1 Transmit Interrupt ........................................ 37 USART2 Receive Interrupt ......................................... 38 Vectors Peripheral Interrupt............................................. 39 Program Memory Locations ............................... 43 RA0/INT Interrupt ............................................... 39 T0CKI Interrupt ................................................... 39 Vectors/Priorities......................................................... 39 Wake-up from SLEEP............................................... 194 INTF.................................................................................... 34 INTSTA Register................................................................. 34 IORLW .............................................................................. 214 IORWF .............................................................................. 215 IRBPU VS. VDD ................................................................... 274
K
KeeLoq Evaluation and Programming Tools .................... 236
L
LCALL......................................................................... 54, 215
M
Maps Register File Map........................................................ 47 Memory External Interface ....................................................... 45 External Memory Waveforms ..................................... 45 Memory Map (Different Modes) .................................. 44 Mode Memory Access ................................................ 44 Organization ............................................................... 43 Program Memory ........................................................ 43 Program Memory Map ................................................ 43 Microcontroller .................................................................... 43 Microprocessor ................................................................... 43 Minimizing Current Consumption...................................... 195 MOVFP ....................................................................... 46, 216 Moving Data Between Data and Program Memories ......... 46 MOVLB ....................................................................... 46, 216 MOVLR ............................................................................. 217 MOVLW ............................................................................ 217
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MOVPF ....................................................................... 46, 218 MOVWF ............................................................................ 218 MPLAB Integrated Development Environment Software .. 233 MULLW ............................................................................. 219 Multi-Master Communication ............................................ 170 Multi-Master Mode ............................................................ 152 Multiply Examples 16 x 16 Routine........................................................... 68 16 x 16 Signed Routine............................................... 69 8 x 8 Routine............................................................... 67 8 x 8 Signed Routine................................................... 67 MULWF ............................................................................. 219 PORTB ................................................................... 27, 48, 74 PORTB Interrupt on Change .............................................. 37 PORTC ................................................................... 28, 48, 78 PORTD ................................................................... 28, 48, 80 PORTE ................................................................... 28, 48, 82 PORTF ............................................................................... 49 PORTG ............................................................................... 49 Power-down Mode............................................................ 194 Power-on Reset (POR)....................................................... 24 Power-up Timer (PWRT) .................................................... 24 PR1............................................................................... 28, 49 PR2............................................................................... 28, 49 PR3/CA1H .......................................................................... 28 PR3/CA1L........................................................................... 28 PR3H/CA1H........................................................................ 49 PR3L/CA1L......................................................................... 49 Prescaler Assignments ....................................................... 99 PRO MATE" II Universal Programmer.............................. 235 PRODH......................................................................... 30, 50 PRODL ......................................................................... 30, 50 Program Counter (PC)........................................................ 56 Program Memory External Access Waveforms....................................... 45 External Connection Diagram..................................... 45 Map............................................................................. 43 Modes Extended Microcontroller.................................... 43 Microcontroller .................................................... 43 Microprocessor ................................................... 43 Protected Microcontroller.................................... 43 Operation.................................................................... 43 Organization ............................................................... 43 Protected Microcontroller.................................................... 43 PS0 ............................................................................... 53, 97 PS1 ............................................................................... 53, 97 PS2 ............................................................................... 53, 97 PS3 ............................................................................... 53, 97 PUSH............................................................................ 39, 54 PW1DCH ...................................................................... 28, 49 PW1DCL....................................................................... 28, 49 PW2DCH ...................................................................... 28, 49 PW2DCL....................................................................... 28, 49 PW3DCH ...................................................................... 30, 50 PW3DCL....................................................................... 30, 50 PWM ......................................................................... 101, 107 Duty Cycle ................................................................ 108 External Clock Source .............................................. 109 Frequency vs. Resolution ......................................... 108 Interrupts .................................................................. 108 Max Resolution/Frequency for External Clock Input 109 Output....................................................................... 107 Periods ..................................................................... 108 PWM1 ....................................................................... 102, 103 PWM1ON.................................................................. 102, 107 PWM2 ....................................................................... 102, 103 PWM2ON.................................................................. 102, 107 PWM3ON.......................................................................... 103 PWRT ................................................................................. 24
N
NEGW ............................................................................... 220 NOP .................................................................................. 220
O
Opcode Field Descriptions ................................................ 197 Opcodes.............................................................................. 56 Oscillator Configuration....................................................... 17, 192 Crystal......................................................................... 17 External Clock............................................................. 19 External Crystal Circuit ............................................... 19 External Parallel Resonant Crystal Circuit .................. 19 External Series Resonant Crystal Circuit.................... 19 RC............................................................................... 20 RC Frequencies ........................................................ 269 Oscillator Start-up Time (Figure)......................................... 24 Oscillator Start-up Timer (OST) .......................................... 24 OST..................................................................................... 24 OV ................................................................................. 11, 51 Overflow (OV) ..................................................................... 11
P
P........................................................................................ 134 Packaging Information ...................................................... 281 PC (Program Counter) ........................................................ 56 PCFG0 bit ......................................................................... 180 PCFG1 bit ......................................................................... 180 PCFG2 bit ......................................................................... 180 PCH .................................................................................... 56 PCL ............................................................................. 56, 198 PCLATH .............................................................................. 56 PD ............................................................................... 52, 194 PEIE ............................................................................ 34, 111 PEIF .................................................................................... 34 Peripheral Bank .................................................................. 57 Peripheral Banks................................................................. 57 Peripheral Interrupt Enable ................................................. 35 Peripheral Interrupt Request (PIR1) ................................... 37 Peripheral Register Banks .................................................. 46 PICDEM-1 Low-Cost PICmicro Demo Board.................... 235 PICDEM-2 Low-Cost PIC16CXX Demo Board ................. 235 PICDEM-3 Low-Cost PIC16CXXX Demo Board............... 236 PICSTART" Plus Entry Level Development System ......... 235 PIE .................................................................... 126, 130, 132 PIE1 .............................................................................. 28, 48 PIE2 ........................................................................ 28, 36, 49 PIR .................................................................... 126, 130, 132 PIR1 .............................................................................. 28, 48 PIR2 .............................................................................. 28, 49 PM0........................................................................... 191, 195 PM1........................................................................... 191, 195 POP .............................................................................. 39, 54 POR .................................................................................... 24 PORTA.................................................................... 27, 48, 72
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R
R/W ................................................................................... 134 R/W bit .............................................................................. 145 R/W bit .............................................................................. 145 RA1/T0CKI pin .................................................................... 97 RBIE.................................................................................... 35 RBIF .................................................................................... 37 RBPU .................................................................................. 74 RC Oscillator ....................................................................... 20 RC Oscillator Frequencies ................................................ 269 RC1IE.................................................................................. 35 RC1IF.................................................................................. 37 RC2IE.................................................................................. 36 RC2IF.................................................................................. 38 RCE, Receive Enable bit, RCE ......................................... 136 RCREG ..................................................... 125, 126, 130, 131 RCREG1 ....................................................................... 27, 48 RCREG2 ....................................................................... 27, 49 RCSTA .............................................................. 126, 130, 132 RCSTA1 ........................................................................ 27, 48 RCSTA2 ........................................................................ 27, 49 Read/Write bit, R/W .......................................................... 134 Reading 16-bit Value........................................................... 99 Receive Overflow Indicator bit, SSPOV ............................ 135 Receive Status and Control Register ................................ 117 Register File Map ................................................................ 47 Registers ADCON0 ..................................................................... 49 ADCON1 ..................................................................... 49 ADRESH ..................................................................... 49 ADRESL...................................................................... 49 ALUSTA .......................................................... 39, 48, 51 BRG .......................................................................... 120 BSR....................................................................... 39, 48 CA2H .......................................................................... 49 CA2L ........................................................................... 49 CA3H .......................................................................... 50 CA3L ........................................................................... 50 CA4H .......................................................................... 50 CA4L ........................................................................... 50 CPUSTA ............................................................... 48, 52 DDRB .......................................................................... 48 DDRC.......................................................................... 48 DDRD.......................................................................... 48 DDRE .......................................................................... 48 DDRF .......................................................................... 49 DDRG ......................................................................... 49 FSR0 ..................................................................... 48, 54 FSR1 ..................................................................... 48, 54 INDF0.................................................................... 48, 54 INDF1.................................................................... 48, 54 INSTA ......................................................................... 48 INTSTA ....................................................................... 34 PCL ............................................................................. 48 PCLATH ...................................................................... 48 PIE1 ...................................................................... 35, 48 PIE2 ...................................................................... 36, 49 PIR1 ...................................................................... 37, 48 PIR2 ...................................................................... 38, 49 PORTA........................................................................ 48 PORTB........................................................................ 48 PORTC ....................................................................... 48 PORTD ....................................................................... 48 PORTE........................................................................ 48 PORTF ........................................................................ 49 PORTG ....................................................................... 49 PR1............................................................................. 49 PR2............................................................................. 49 PR3H/CA1H................................................................ 49 PR3L/CA1L................................................................. 49 PRODH....................................................................... 50 PRODL ....................................................................... 50 PW1DCH .................................................................... 49 PW1DCL..................................................................... 49 PW2/DCL.................................................................... 49 PW2DCH .................................................................... 49 PW3DCH .................................................................... 50 PW3DCL..................................................................... 50 RCREG1..................................................................... 48 RCREG2..................................................................... 49 RCSTA1 ..................................................................... 48 RCSTA2 ..................................................................... 49 SPBRG1 ..................................................................... 48 SPBRG2 ..................................................................... 49 SSPADD ..................................................................... 50 SSPBUF ..................................................................... 50 SSPCON1 .................................................................. 50 SSPCON2 .................................................................. 50 SSPSTAT ........................................................... 50, 134 T0STA ............................................................ 48, 53, 97 TBLPTRH ................................................................... 48 TBLPTRL .................................................................... 48 TCON1 ............................................................... 49, 101 TCON2 ............................................................... 49, 102 TCON3 ............................................................... 50, 103 TMR0H ....................................................................... 48 TMR1 .......................................................................... 49 TMR2 .......................................................................... 49 TMR3H ....................................................................... 49 TMR3L ........................................................................ 49 TXREG1 ..................................................................... 48 TXREG2 ..................................................................... 49 TXSTA1 ...................................................................... 48 TXSTA2 ...................................................................... 49 WREG .................................................................. 39, 48 Regsters TMR0L ........................................................................ 48 Reset Section........................................................................ 23 Status Bits and Their Significance .............................. 25 Time-Out in Various Situations ................................... 25 Time-Out Sequence.................................................... 25 Restart Condition Enabled bit, RSE.................................. 136 RETFIE ............................................................................. 221 RETLW ............................................................................. 221 RETURN........................................................................... 222 RLCF ................................................................................ 222 RLNCF .............................................................................. 223 RRCF ................................................................................ 223 RRNCF ............................................................................. 224 RSE .................................................................................. 136 RX Pin Sampling Scheme ................................................ 125
S
S ....................................................................................... 134 SAE................................................................................... 136 Sampling........................................................................... 125 Saving STATUS and WREG in RAM.................................. 42 SCK .................................................................................. 137 SCL................................................................................... 144 SDA .................................................................................. 144 SDI.................................................................................... 137 SDO .................................................................................. 137
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SEEVAL Evaluation and Programming System................ 236 Serial Clock, SCK ............................................................. 137 Serial Clock, SCL .............................................................. 144 Serial Data Address, SDA................................................. 144 Serial Data In, SDI ............................................................ 137 Serial Data Out, SDO........................................................ 137 SETF ................................................................................. 224 SFR ................................................................................... 198 SFR (Special Function Registers)....................................... 43 SFR As Source/Destination .............................................. 198 Signed Math ........................................................................ 11 Slave Select Synchronization ........................................... 140 Slave Select, SS ............................................................... 137 SLEEP ...................................................................... 194, 225 SLEEP Mode, All Peripherals Disabled ............................ 273 SLEEP Mode, BOR Enabled ............................................ 273 SMP .................................................................................. 134 Software Simulator (MPLAB SIM)..................................... 234 SPBRG ............................................................. 126, 130, 132 SPBRG1 ....................................................................... 27, 48 SPBRG2 ....................................................................... 27, 49 SPE ................................................................................... 136 Special Features of the CPU ............................................ 191 Special Function Registers ......................................... 43, 198 Summary..................................................................... 48 Special Function Registers, File Map ................................. 47 SPI Master Mode ............................................................. 139 Serial Clock............................................................... 137 Serial Data In ............................................................ 137 Serial Data Out ......................................................... 137 Serial Peripheral Interface (SPI) ............................... 133 Slave Select .............................................................. 137 SPI clock ................................................................... 139 SPI Mode .................................................................. 137 SPI Clock Edge Select, CKE ............................................ 134 SPI Data Input Sample Phase Select, SMP ..................... 134 SPI Master/Slave Connection ........................................... 138 SPI Module Master/Slave Connection.......................................... 138 Slave Mode ............................................................... 140 Slave Select Synchronization ................................... 140 Slave Synch Timing .................................................. 140 SS ..................................................................................... 137 SSP ................................................................................... 133 Block Diagram (SPI Mode) ....................................... 137 SPI Mode .................................................................. 137 SSPADD ........................................................... 144, 145 SSPBUF............................................................ 139, 144 SSPCON1................................................................. 135 SSPCON2................................................................. 136 SSPSR.............................................................. 139, 144 SSPSTAT.......................................................... 134, 144 SSP I2C SSP I2C Operation.................................................... 143 SSP Module SPI Master Mode ...................................................... 139 SPI Master/Slave Connection ................................... 138 SPI Slave Mode ........................................................ 140 SSPCON1 Register .................................................. 143 SSP Overflow Detect bit, SSPOV ..................................... 144 SSPADD ............................................................................. 50 SSPBUF...................................................................... 50, 144 SSPCON1 ........................................................... 50, 135, 143 SSPCON2 ................................................................... 50, 136 SSPEN .............................................................................. 135 SSPIE ................................................................................. 36 SSPIF ......................................................................... 38, 145 SSPM3:SSPM0 ................................................................ 135 SSPOV ............................................................. 135, 144, 162 SSPSTAT ........................................................... 50, 134, 144 ST Input ............................................................................ 278 Stack Operation.................................................................... 54 Pointer ........................................................................ 54 Stack........................................................................... 43 START bit (S) ................................................................... 134 START Condition Enabled bit, SAE.................................. 136 STKAV .......................................................................... 52, 54 STOP bit (P) ..................................................................... 134 STOP Condition Enable bit............................................... 136 SUBLW ............................................................................. 225 SUBWF............................................................................. 226 SUBWFB .......................................................................... 226 SWAPF ............................................................................. 227 Synchronous Master Mode............................................... 127 Synchronous Master Reception........................................ 129 Synchronous Master Transmission .................................. 127 Synchronous Serial Port ................................................... 133 Synchronous Serial Port Enable bit, SSPEN.................... 135 Synchronous Serial Port Interrupt....................................... 38 Synchronous Serial Port Interrupt Enable, SSPIE.............. 36 Synchronous Serial Port Mode Select bits, SSPM3:SSPM0 ................................................................ 135 Synchronous Slave Mode................................................. 131
T
T0CKI ................................................................................. 39 T0CKI Pin ........................................................................... 40 T0CKIE ............................................................................... 34 T0CKIF ............................................................................... 34 T0CS ............................................................................ 53, 97 T0IE .................................................................................... 34 T0IF .................................................................................... 34 T0SE............................................................................. 53, 97 T0STA ................................................................................ 53 T16 ................................................................................... 101 Table Latch ......................................................................... 55 Table Pointer ...................................................................... 55 Table Read Example...................................................................... 64 Table Reads Section .................................................. 64 TLRD .......................................................................... 64 Table Write Code ........................................................................... 62 Timing......................................................................... 62 To External Memory ................................................... 62 TABLRD ................................................................... 227, 228 TABLWT ................................................................... 228, 229 TAD ................................................................................... 185 TBLATH .............................................................................. 55 TBLATL .............................................................................. 55 TBLPTRH ........................................................................... 55 TBLPTRL ............................................................................ 55 TCLK12 ............................................................................ 101 TCLK3 .............................................................................. 101 TCON1 ......................................................................... 28, 49 TCON2 ............................................................................... 49 TCON2,TCON3 .................................................................. 28 TCON3 ....................................................................... 50, 103 Time-Out Sequence............................................................ 25 Timer Resources ................................................................ 95
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Timer0 ................................................................................. 97 Timer1 16-bit Mode ............................................................... 105 Clock Source Select.................................................. 101 On bit ................................................................ 102, 103 Section .............................................................. 101, 104 Timer2 16-bit Mode ............................................................... 105 Clock Source Select.................................................. 101 On bit ................................................................ 102, 103 Section .............................................................. 101, 104 Timer3 Clock Source Select.................................................. 101 On bit ................................................................ 102, 103 Section .............................................................. 101, 110 Timers TCON3 ...................................................................... 103 Timing Diagrams A/D Conversion ......................................................... 264 Acknowledge Sequence Timing................................ 165 Asynchronous Master Transmission ......................... 123 Asynchronous Reception .......................................... 126 Back to Back Asynchronous Master Transmission ... 124 Baud Rate Generator with Clock Arbitration ............. 153 BRG Reset Due to SDA Collision ............................. 172 Bus Collision START Condition Timing .................................. 171 Bus Collision During a RESTART Condition (Case 1) .................................................................... 173 Bus Collision During a RESTART Condition (Case 2) .................................................................... 173 Bus Collision During a START Condition (SCL = 0)................................................................... 172 Bus Collision During a STOP Condition ........................................................ 174 Bus Collision for Transmit and Acknowledge............ 170 External Parallel Resonant Crystal Oscillator Circuit .. 19 External Program Memory Access ............................. 45 I2C Bus Data ............................................................. 259 I2C Bus START/STOP bits ....................................... 258 I2C Master Mode First START bit Timing ................. 154 I2C Master Mode Reception Timing .......................... 164 I2C Master Mode Transmission Timing..................... 161 Interrupt (INT, TMR0 Pins).......................................... 40 Master Mode Transmit Clock Arbitration................... 169 Oscillator Start-up Time .............................................. 24 PIC17C752/756 Capture Timing ............................... 253 PIC17C752/756 CLKOUT and I/O ............................ 250 PIC17C752/756 External Clock ................................ 249 PIC17C752/756 Memory Interface Read .................. 266 PIC17C752/756 Memory Interface Write .................. 265 PIC17C752/756 PWM Timing ................................... 253 PIC17C752/756 Reset, Watchdog Timer, Oscillator Start-up Timer and Power-up Timer ......................... 251 PIC17C752/756 Timer0 Clock .................................. 252 PIC17C752/756 Timer1, Timer2 and Timer3 Clock .. 252 PIC17C752/756 USART Module Synchronous Receive ..................................................................... 261 PIC17C752/756 USART Module Synchronous Transmission....................................... 260 Repeat START Condition ......................................... 156 Slave Synchronization .............................................. 140 STOP Condition Receive or Transmit ....................... 167 Synchronous Reception ............................................ 129 Synchronous Transmission....................................... 128 Table Write.................................................................. 62 TMR0 .................................................................... 98, 99 TMR0 Read/Write in Timer Mode ............................. 100 TMR1, TMR2, and TMR3 in Timer Mode ................. 115 Wake-Up from SLEEP .............................................. 194 TLRD ................................................................................ 229 TLWT ................................................................................ 230 TMR0 16-bit Read ................................................................. 99 16-bit Write ................................................................. 99 Module ........................................................................ 98 Operation .................................................................... 98 Overview..................................................................... 95 Prescaler Assignments ............................................... 99 Read/Write Considerations......................................... 99 Read/Write in Timer Mode........................................ 100 Timing ................................................................... 98, 99 TMR0 Status/Control Register (T0STA) ............................. 53 TMR1 ............................................................................ 28, 49 8-bit Mode................................................................. 104 External Clock Input.................................................. 104 Overview..................................................................... 95 Timer Mode............................................................... 115 Two 8-bit Timer/Counter Mode ................................. 104 Using with PWM ....................................................... 107 TMR1 Overflow Interrupt .................................................... 37 TMR1CS ........................................................................... 101 TMR1IE............................................................................... 35 TMR1IF............................................................................... 37 TMR1ON........................................................................... 102 TMR2 ............................................................................ 28, 49 8-bit Mode................................................................. 104 External Clock Input.................................................. 104 In Timer Mode........................................................... 115 Two 8-bit Timer/Counter Mode ................................. 104 Using with PWM ....................................................... 107 TMR2 Overflow Interrupt .................................................... 37 TMR2CS ........................................................................... 101 TMR2IE............................................................................... 35 TMR2IF............................................................................... 37 TMR2ON........................................................................... 102 TMR3 Example, Reading From ........................................... 114 Example, Writing To ................................................. 114 External Clock Input.................................................. 114 In Timer Mode........................................................... 115 One Capture and One Period Register Mode........... 110 Overview..................................................................... 95 Reading/Writing ........................................................ 114 TMR3 Interrupt Flag bit, TMR3IF ........................................ 37 TMR3CS ................................................................... 101, 110 TMR3H ......................................................................... 28, 49 TMR3IE............................................................................... 35 TMR3IF....................................................................... 37, 110 TMR3L .......................................................................... 28, 49 TMR3ON................................................................... 102, 110 TO....................................................................... 52, 193, 194 Transmit Status and Control Register............................... 117 TSTFSZ ............................................................................ 230 TTL INPUT........................................................................ 278 Turning on 16-bit Timer .................................................... 105 TX1IE.................................................................................. 35 TX1IF .................................................................................. 37 TX2IE.................................................................................. 36 TX2IF .................................................................................. 38 TXREG ..................................................... 123, 127, 131, 132 TXREG1 ....................................................................... 27, 48
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TXREG2........................................................................ 27, 49 TXSTA .............................................................. 126, 130, 132 TXSTA Register TXEN Bit ......................................... 34, 51, 97, 101, 117 TXSTA1 ........................................................................ 27, 48 TXSTA2 ........................................................................ 27, 49
W
Wake-up from SLEEP....................................................... 194 Wake-up from SLEEP Through Interrupt.......................... 194 Watchdog Timer ............................................................... 193 Waveform for General Call Address Sequence................ 149 Waveforms External Program Memory Access ............................. 45 WCOL ....................................... 135, 154, 159, 162, 165, 167 WCOL Status Flag............................................................ 154 WDT ................................................................................. 193 Clearing the WDT ..................................................... 193 Normal Timer............................................................ 193 Period ....................................................................... 193 Programming Considerations ................................... 193 WDT PERIOD................................................................... 275 WDTPS0........................................................................... 191 WDTPS1........................................................................... 191 Write Collision Detect bit, WCOL...................................... 135 WWW, On-Line Support ....................................................... 5
U
UA ..................................................................................... 134 Update Address, UA ......................................................... 134 Upward Compatibility ............................................................ 7 USART Asynchronous Master Transmission......................... 123 Asynchronous Mode ................................................. 123 Asynchronous Receive ............................................. 125 Asynchronous Transmitter ........................................ 123 Baud Rate Generator................................................ 120 Synchronous Master Mode ....................................... 127 Synchronous Master Reception................................ 129 Synchronous Master Transmission........................... 127 Synchronous Slave Mode ......................................... 131 Synchronous Slave Transmit .................................... 131 Transmit Enable (TXEN Bit)............ 34, 51, 97, 101, 117 USART1 Receive Interrupt ................................................. 37 USART1 Transmit Interrupt ................................................ 37 USART2 Receive Interrupt Enable, RC2IE......................... 36 USART2 Receive Interrupt Flag bit, RC2IF ........................ 38 USART2 Receive Interrupt Flag bit, TX2IF ......................... 38 USART2 Transmit Interrupt Enable, TX2IE ........................ 36
X
XORLW ............................................................................ 231 XORWF ............................................................................ 231
Z
Z ................................................................................... 11, 51 Zero (Z)............................................................................... 11
V
VDD.................................................................................... 242 VOH VS. IOH ....................................................................... 276 VOL VS. IOL ........................................................................ 276
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NOTES:
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ON-LINE SUPPORT
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READER RESPONSE
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PIC17C7XX
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. Device X Temperature Range /XX Package XXX Pattern Examples:
a)
PIC17C756 - 16L Commercial Temp., PLCC package, 16 MHz, normal VDD limits PIC17LC756-08/PT Commercial Temp., TQFP package, 8MHz, extended VDD limits PIC17C756-33I/PT Industrial Temp., TQFP package, 33 MHz, normal VDD limits
b)
Device PIC17C756: Standard VDD range PIC17C756T: (Tape and Reel) PIC17LC756: Extended VDD range
c)
Temperature Range I = 0C to = -40C to +70C +85C
Package
CL PT L
= = =
Windowed LCC TQFP PLCC
Pattern
QTP, SQTP, ROM Code (factory specified) or Special Requirements . Blamk for OTP and Windowed devices.
* JW Devices are UV erasable and can be programmed to any device configuration. JW Devices meet the electrical requirement of each oscillator type.
Sales and Support
Data Sheets Products supported by a preliminary Data Sheet may have an errata sheet describing minor operational differences and recommended workarounds. To determine if an errata sheet exists for a particular device, please contact one of the following: 1. 2. 3. Your local Microchip sales office The Microchip Corporate Literature Center U.S. FAX: (480) 792-7277 The Microchip Worldwide Site (www.microchip.com)
Please specify which device, revision of silicon and Data Sheet (include Literature #) you are using. New Customer Notification System Register on our web site (www.microchip.com/cn) to receive the most current information on our products.
2000 Microchip Technology Inc.
DS30289B-page 301
PIC17C7XX
NOTES:
DS30289B-page 302
2000 Microchip Technology Inc.
PIC17C7XX
NOTES:
2000 Microchip Technology Inc.
DS30289B-page 303
WORLDWIDE SALES AND SERVICE
AMERICAS
Corporate Office
2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-792-7200 Fax: 480-792-7277 Technical Support: 480-792-7627 Web Address: http://www.microchip.com
ASIA/PACIFIC
China - Beijing
Microchip Technology Beijing Office Unit 915 New China Hong Kong Manhattan Bldg. No. 6 Chaoyangmen Beidajie Beijing, 100027, No. China Tel: 86-10-85282100 Fax: 86-10-85282104
ASIA/PACIFIC (continued)
Singapore
Microchip Technology Singapore Pte Ltd. 200 Middle Road #07-02 Prime Centre Singapore, 188980 Tel: 65-334-8870 Fax: 65-334-8850
Rocky Mountain
2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-792-7966 Fax: 480-792-7456
Taiwan
Microchip Technology Taiwan 11F-3, No. 207 Tung Hua North Road Taipei, 105, Taiwan Tel: 886-2-2717-7175 Fax: 886-2-2545-0139
China - Shanghai
Microchip Technology Shanghai Office Room 701, Bldg. B Far East International Plaza No. 317 Xian Xia Road Shanghai, 200051 Tel: 86-21-6275-5700 Fax: 86-21-6275-5060
Atlanta
500 Sugar Mill Road, Suite 200B Atlanta, GA 30350 Tel: 770-640-0034 Fax: 770-640-0307
EUROPE
Denmark
Microchip Technology Denmark ApS Regus Business Centre Lautrup hoj 1-3 Ballerup DK-2750 Denmark Tel: 45 4420 9895 Fax: 45 4420 9910
Boston
2 Lan Drive, Suite 120 Westford, MA 01886 Tel: 978-692-3838 Fax: 978-692-3821
Hong Kong
Microchip Asia Pacific RM 2101, Tower 2, Metroplaza 223 Hing Fong Road Kwai Fong, N.T., Hong Kong Tel: 852-2401-1200 Fax: 852-2401-3431
Chicago
333 Pierce Road, Suite 180 Itasca, IL 60143 Tel: 630-285-0071 Fax: 630-285-0075
India
Microchip Technology Inc. India Liaison Office Divyasree Chambers 1 Floor, Wing A (A3/A4) No. 11, O'Shaugnessey Road Bangalore, 560 025, India Tel: 91-80-2290061 Fax: 91-80-2290062
France
Arizona Microchip Technology SARL Parc d'Activite du Moulin de Massy 43 Rue du Saule Trapu Batiment A - ler Etage 91300 Massy, France Tel: 33-1-69-53-63-20 Fax: 33-1-69-30-90-79
Dallas
4570 Westgrove Drive, Suite 160 Addison, TX 75001 Tel: 972-818-7423 Fax: 972-818-2924
Dayton
Two Prestige Place, Suite 130 Miamisburg, OH 45342 Tel: 937-291-1654 Fax: 937-291-9175
Germany
Arizona Microchip Technology GmbH Gustav-Heinemann Ring 125 D-81739 Munich, Germany Tel: 49-89-627-144 0 Fax: 49-89-627-144-44
Japan
Microchip Technology Intl. Inc. Benex S-1 6F 3-18-20, Shinyokohama Kohoku-Ku, Yokohama-shi Kanagawa, 222-0033, Japan Tel: 81-45-471- 6166 Fax: 81-45-471-6122
Detroit
Tri-Atria Office Building 32255 Northwestern Highway, Suite 190 Farmington Hills, MI 48334 Tel: 248-538-2250 Fax: 248-538-2260
Italy
Arizona Microchip Technology SRL Centro Direzionale Colleoni Palazzo Taurus 1 V. Le Colleoni 1 20041 Agrate Brianza Milan, Italy Tel: 39-039-65791-1 Fax: 39-039-6899883
Korea
Microchip Technology Korea 168-1, Youngbo Bldg. 3 Floor Samsung-Dong, Kangnam-Ku Seoul, Korea Tel: 82-2-554-7200 Fax: 82-2-558-5934
Los Angeles
18201 Von Karman, Suite 1090 Irvine, CA 92612 Tel: 949-263-1888 Fax: 949-263-1338
United Kingdom
Arizona Microchip Technology Ltd. 505 Eskdale Road Winnersh Triangle Wokingham Berkshire, England RG41 5TU Tel: 44 118 921 5869 Fax: 44-118 921-5820
10/01/00
New York
150 Motor Parkway, Suite 202 Hauppauge, NY 11788 Tel: 631-273-5305 Fax: 631-273-5335
San Jose
Microchip Technology Inc. 2107 North First Street, Suite 590 San Jose, CA 95131 Tel: 408-436-7950 Fax: 408-436-7955
Toronto
6285 Northam Drive, Suite 108 Mississauga, Ontario L4V 1X5, Canada Tel: 905-673-0699 Fax: 905-673-6509
Microchip received QS-9000 quality system certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona in July 1999. The Company's quality system processes and procedures are QS-9000 compliant for its PICmicro(R) 8-bit MCUs, KEELOQ(R) code hopping devices, Serial EEPROMs and microperipheral products. In addition, Microchip's quality system for the design and manufacture of development systems is ISO 9001 certified.
All rights reserved. (c) 2000 Microchip Technology Incorporated. Printed in the USA. 11/00
Printed on recycled paper.
Information contained in this publication regarding device applications and the like is intended through suggestion only and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. No representation or warranty is given and no liability is assumed by Microchip Technology Incorporated with respect to the accuracy or use of such information, or infringement of patents or other intellectual property rights arising from such use or otherwise. Use of Microchip's products as critical components in life support systems is not authorized except with express written approval by Microchip. No licenses are conveyed, implicitly or otherwise, except as maybe explicitly expressed herein, under any intellectual property rights. The Microchip logo and name are registered trademarks of Microchip Technology Inc. in the U.S.A. and other countries. All rights reserved. All other trademarks mentioned herein are the property of their respective companies.
DS30289B-page 304
2000 Microchip Technology Inc.

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