PIC17C7XX High-Performance 8-Bit CMOS EPROM Microcontrollers with 10-bit A/D Pin Diagrams Memory Device Program (x16) Data (x8) 8K 16K 8K 16K 678 902 678 902 PIC17C752 PIC17C756A PIC17C762 PIC17C766 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 SPI™ and I2C™ modes (including I2C master mode) 1998 Microchip Technology Inc. 84 LCC 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 • 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 64K x 16 program memory space 11 10 9 8 7 6 5 4 3 2 1 84 83 82 81 80 79 78 77 76 75 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 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 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 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 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 Microcontroller Core Features: 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 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 µA typical @ 4.5V, 32 kHz - < 1 µA typical standby current @ 5V DS30289A-page 1 PIC17C7XX 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 Pin Diagrams cont.’d 9 8 7 6 5 4 3 2 1 68 67 66 65 64 63 62 61 68-Pin LCC 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 PIC17C75X 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 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 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 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 64 63 62 61 60 59 64-Pin TQFP 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 PIC17C75X 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 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 58 57 56 55 54 53 52 51 50 49 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 NC VSS VDD RF7/AN11 RF6/AN10 RF5/AN9 RF4/AN8 RF3/AN7 RF2/AN6 DS30289A-page 2 1998 Microchip Technology Inc. PIC17C7XX PIN DIAGRAMS cont.’d 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-pin LCC 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 7978777675 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 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 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 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 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-Pin QFP 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 PIC17C76X 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 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 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 3637 38 39 40 1998 Microchip Technology Inc. DS30289A-page 3 PIC17C7XX Table of Contents 1.0 Overview ...........................................................................................................................................................5 2.0 Device Varieties ................................................................................................................................................7 3.0 Architectural Overview ......................................................................................................................................9 4.0 On-chip Oscillator Circuit ................................................................................................................................15 5.0 Reset...............................................................................................................................................................21 6.0 Interrupts.........................................................................................................................................................31 7.0 Memory Organization......................................................................................................................................41 8.0 Table Reads and Table Writes .......................................................................................................................57 9.0 Hardware Multiplier .........................................................................................................................................65 10.0 I/O Ports..........................................................................................................................................................69 11.0 Overview of Timer Resources.........................................................................................................................93 12.0 Timer0.............................................................................................................................................................95 13.0 Timer1, Timer2, Timer3, PWMs and Captures ...............................................................................................99 14.0 Universal Synchronous Asynchronous Receiver Transmitter (USART) Modules.........................................115 15.0 Master Synchronous Serial Port (MSSP) Module.........................................................................................131 16.0 Analog-to-Digital Converter (A/D) Module ....................................................................................................177 17.0 Special Features of the CPU ........................................................................................................................189 18.0 Instruction Set Summary...............................................................................................................................195 19.0 Development Support ...................................................................................................................................231 20.0 PIC17C7XX Electrical Characteristics ..........................................................................................................235 21.0 PIC17C7XX DC and AC Characteristics.......................................................................................................265 22.0 Packaging Information ..................................................................................................................................277 Appendix A: Modifications..........................................................................................................................................283 Appendix B: Compatibility ..........................................................................................................................................283 Appendix C: What’s New............................................................................................................................................284 Appendix D: What’s Changed ....................................................................................................................................284 Appendix E: I2C Overview.......................................................................................................................................285 Appendix F: Status and Control Registers.................................................................................................................291 On-Line Support ..........................................................................................................................................................321 Reader Response .......................................................................................................................................................322 PIC17C7XX Product Identification System .................................................................................................................323 To Our Valued Customers Most Current Data Sheet To obtain the most up-to-date version of this data sheet, please check our Worldwide Web site at: http://www.microchip.com You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page. The last character of the literature number is the version number. e.g., DS30000A is version A of document DS30000. Errata An errata sheet may exist for current devices, describing minor operational differences (from the data sheet) and recommended workarounds. 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: (602) 786-7277 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. Corrections to this Data Sheet We constantly strive to improve the quality of all our products and documentation. We have spent a great deal of time to ensure that this document is correct. However, we realize that we may have missed a few things. If you find any information that is missing or appears in error, please: • Fill out and mail in the reader response form in the back of this data sheet. • E-mail us at [email protected]. We appreciate your assistance in making this a better document. DS30289A-page 4 1998 Microchip Technology Inc. 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 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™ 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. 1998 Microchip Technology Inc. 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 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. DS30289A-page 5 PIC17C7XX TABLE 1-1: PIC17CXXX FAMILY OF DEVICES 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 Current Capability Source Sink PIC17C43 PIC17C44 PIC17C752 33 MHz 33 MHz 33 MHz 33 MHz PIC17C756A PIC17C762 33 MHz 33 MHz 33 MHz 2.5 - 6.0V 2.5 - 6.0V 2.5 - 6.0V 3.0 - 5.5V 3.0 - 5.5V 3.0 - 5.5V 3.0 - 5.5V 2K — 4K — 8K — 8K — 16K — 8K — 16K — 232 454 454 678 902 678 902 Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes 2 2 2 2 2 2 4 3 4 3 4 3 4 3 1 — — 1 — — 1 — — 2 12 Yes 2 12 Yes 2 16 Yes 2 16 Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes 11 Yes Yes 11 Yes Yes 11 Yes Yes 18 Yes Yes 18 Yes Yes 18 Yes Yes 18 Yes — Yes — Yes — Yes Yes Yes Yes Yes Yes Yes Yes — — — Yes Yes Yes Yes 33 25 mA 33 25 mA 33 25 mA 50 25 mA 50 25 mA 66 25 mA 66 25 mA 25 mA(1) 25 mA(1) 25 mA(1) 25 mA(1) 25 mA(1) 25 mA(1) 40-pin DIP 40-pin DIP 40-pin DIP 64-pin DIP 64-pin DIP 80-pin QFP 44-pin PLCC 44-pin PLCC 44-pin PLCC 68-pin LCC 68-pin LCC 84-pin 44-pin 44-pin 44-pin 68-pin TQFP 68-pin TQFP PLCC MQFP MQFP MQFP 44-pin TQFP 44-pin TQFP 44-pin TQFP Pins RA2 and RA3 can sink up to 60 mA. Package Types Note 1: PIC17C42A DS30289A-page 6 PIC17C766 25 mA(1) 80-pin QFP 84-pin PLCC 1998 Microchip Technology Inc. PIC17C7XX 2.0 DEVICE VARIETIES 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 three memory type options. These are specified in the middle characters of the part number. 1. 2. 3. C, as in PIC17C756A. These devices have EPROM type memory. CR, as in PIC17CR756A. These devices have ROM type memory. F, as in PIC17F756A. These devices have Flash type memory. 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. TABLE 2-1: DEVICE MEMORY VARIETIES Voltage Range Standard Extended PIC17CXXX PIC17LCXXX PIC17CRXXX PIC17LCRXXX PIC17FXXX PIC17LFXXX Not all memory technologies are available for a particular device. Memory Type EPROM ROM Flash Note: 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. 2.3 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 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. 1998 Microchip Technology Inc. DS30289A-page 7 PIC17C7XX 2.5 Read Only Memory (ROM) Devices 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: 2.6 Presently, NO ROM versions of the PIC17C7XX devices are available. Flash Memory Devices These devices are electrically erasable and, therefore, can be offered in the low cost plastic package. Being electrically erasable, these devices can be erased and reprogrammed in-circuit. These devices are the same for prototype development, pilot programs, as well as production. Note: Presently, NO Flash versions of the PIC17C7XX devices are available. DS30289A-page 8 1998 Microchip Technology Inc. PIC17C7XX 3.0 ARCHITECTURAL OVERVIEW 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 two-stage 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. 1998 Microchip Technology Inc. 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 an 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. EXAMPLE 3-1: Hex Value + = FFh 01h 00h 8-BIT MATH ADDITION Signed Values + = -1 1 0 (FEh) Unsigned Values 255 + 1 = 256 → 00h C bit = 1 OV bit = 0 C bit = 1 OV bit = 0 C bit = 1 OV bit = 0 DC bit = 1 Z bit = 1 DC bit = 1 Z bit = 1 DC bit = 1 Z bit = 1 Hex Value Signed Values Unsigned Values + = 7Fh 01h 80h + = 127 1 128 → 00h 127 + 1 = 128 C bit = 0 OV bit = 1 C bit = 0 OV bit = 1 C bit = 0 OV bit = 1 DC bit = 1 Z bit = 0 DC bit = 1 Z bit = 0 DC bit = 1 Z bit = 0 DS30289A-page 9 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 WREG<8> BITOP Clock Generator Q1, Q2, Q3, Q4 IR<16> OSC1, OSC2 Power-on Reset Brown-out VDD, VSS Reset PORTB 8 x 8 mult RB0/CAP1 RB1/CAP2 RB2/PWM1 RB3/PWM2 RB4/TCLK12 RB5/TCLK3 RB6/SCK RB7/SDO Chip_reset & Other Control Signals ALU PRODH PRODL Shifter Watchdog Timer MCLR, VPP Test Mode Select Test IR Latch <16> 8 8 8 BSR <7:4> IR <7:0> PORTC RC0/AD0 RC1/AD1 RC2/AD2 RC3/AD3 RC4/AD4 RC5/AD5 RC6/AD6 RC7/AD7 16 F1 F9 12 RAM Address Buffer Data RAM 17C756A 902 x 8 17C752 678 x 8 PORTD RD0/AD8 RD1/AD9 RD2/AD10 RD3/AD11 RD4/AD12 RD5/AD13 RD6/AD14 RD7/AD15 Read/write Decode for Registers Mapped in Data Space Instruction Decode Control Outputs ROM Latch <16> Decode 8 AD<15:0> PORTC, PORTD BSR Literal Table Latch <16> Data Latch Program Memory (EPROM) 17C756A 16K x 16 17C752 8K x 16 PORTE RE0/ALE RE1/OE RE2/WR RE3/CAP4 ALE, WR, OE, PORTE Address Latch Table Pointer<16> PCLATH<8> System Bus Interface Data Latch 16 16 PORTF RF0/AN4 RF1/AN5 RF2/AN6 RF3/AN7 RF4/AN8 RF5/AN9 RF6/AN10 RF7/AN11 PCH PCL 16 Stack 16 x 16 16 Data Bus<8> Timer0 Timer2 USART1 PWM1 PWM3 Capture2 10-bit A/D SSP Timer1 Timer3 USART2 PWM2 Capture1 Capture3 Capture4 Interrupt Module PORTG RG0/AN3 RG1/AN2 RG2/AN1/VREFRG3/AN0/VREF+ RG4/CAP3 RG5/PWM3 RG6/RX2/DT2 RG7/TX2/CK2 DS30289A-page 10 1998 Microchip Technology Inc. PIC17C7XX PIC17C762/766 BLOCK DIAGRAM PORTA Clock Generator RA0/INT RA1/T0CKI RA2/SS/SCL RA3/SDI/SDA RA4/RX1/DT1 RA5/TX1/CK1 WREG<8> Q1, Q2, Q3, Q4 IR<16> BITOP Chip_reset & Other Control Signals PORTB RB0/CAP1 RB1/CAP2 RB2/PWM1 RB3/PWM2 RB4/TCLK12 RB5/TCLK3 RB6/SCK RB7/SDO 8 x 8 mult ALU OSC1, OSC2 Power-on Reset Watchdog Timer VDD, VSS Test Mode Select MCLR, VPP Brown-out Reset Test AVDD, AVSS PRODH PRODL Shifter IR Latch <16> PORTC RC0/AD0 RC1/AD1 RC2/AD2 RC3/AD3 RC4/AD4 RC5/AD5 RC6/AD6 RC7/AD7 8 8 8 BSR <7:4> IR <7:0> 16 FSR0 FSR1 12 RAM Address Buffer Data RAM 17C766 902 x 8 and 17C762 678 x 8 Data Latch 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 BSR Read/write Decode for Registers Mapped in Data Space Instruction Decode Control Outputs Literal ROM Latch <16> 8 AD<15:0> PORTC, PORTD Table Latch <16> Data Latch Program Memory (EPROM) 17C766 16K x 16, and 17C762 8K x 16 PORTF RF0/AN4 RF1/AN5 RF2/AN6 RF3/AN7 RF4/AN8 RF5/AN9 RF6/AN10 RF7/AN11 Decode System Bus Interface FIGURE 3-2: ALE, WR, OE, PORTE Address Latch Table Pointer<16> PCLATH<8> 16 PORTG RG0/AN3 RG1/AN2 RG2/AN1/VREFRG3/AN0/VREF+ RG4/CAP3 RG5/PWM3 RG6/RX2/DT2 RG7/TX2/CK2 16 PCH PCL 16 Stack 16 x 16 16 Data Bus<8> PORTJ RJ0 RJ1 RJ2 RJ3 RJ4 RJ5 RJ6 RJ7 PORTH RH0 RH1 RH2 RH3 RH4/AN12 RH5/AN13 RH6/AN14 RH7/AN15 1998 Microchip Technology Inc. Timer0 Timer2 USART1 PWM1 PWM3 Timer1 Timer3 USART2 PWM2 Capture1 Interrupt Module SSP 10-bit A/D Capture2 Capture3 Capture4 DS30289A-page 11 PIC17C7XX TABLE 3-1: PINOUT DESCRIPTIONS PIC17C75X Name PIC17C76X DIP No. PLCC No. TQFP No. PLCC No. QFP No. I/O/P Type Buffer Type OSC1/CLKIN 47 50 39 62 49 I ST Oscillator input in crystal/resonator or RC oscillator mode. External clock input in external clock mode. OSC2/CLKOUT 48 51 40 63 50 O — 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. MCLR/VPP 15 16 7 20 9 I/P ST RA0/INT 56 60 48 72 58 I ST 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 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: 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/TX1/CK1 39 42 31 50 37 I/O (1) ST RB0/CAP1 RB1/CAP2 RB2/PWM1 RB3/PWM2 RB4/TCLK12 55 54 50 53 52 59 58 54 57 56 47 46 42 45 44 71 70 66 69 68 57 56 52 55 54 I/O I/O I/O I/O I/O ST ST ST ST ST RB5/TCLK3 51 55 43 67 53 I/O ST RB6/SCK 44 47 36 59 46 I/O ST RB7/SDO 45 48 37 60 47 I/O ST Legend: I = Input only; P = Power; O = Output only; — = Not Used; I/O = Input/Output; TTL = TTL input; Description 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. 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. 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. DS30289A-page 12 1998 Microchip Technology Inc. PIC17C7XX TABLE 3-1: PINOUT DESCRIPTIONS PIC17C75X Name PIC17C76X DIP No. PLCC No. TQFP No. PLCC No. QFP No. I/O/P Type Buffer Type RC0/AD0 RC1/AD1 2 63 3 67 58 55 3 83 72 69 I/O I/O TTL TTL RC2/AD2 62 66 54 82 68 I/O TTL RC3/AD3 61 65 53 81 67 I/O TTL RC4/AD4 RC5/AD5 60 58 64 63 52 51 80 79 66 65 I/O I/O TTL TTL RC6/AD6 58 62 50 78 64 I/O TTL RC7/AD7 57 61 49 77 63 I/O TTL RD0/AD8 10 11 2 15 4 I/O TTL RD1/AD9 RD2/AD10 RD3/AD11 9 8 7 10 9 8 1 64 63 14 9 8 3 78 77 I/O I/O I/O TTL TTL TTL RD4/AD12 6 7 62 7 76 I/O TTL RD5/AD13 RD6/AD14 RD7/AD15 5 4 3 6 5 4 61 60 59 6 5 4 75 74 73 I/O I/O I/O TTL TTL TTL RE0/ALE 11 12 3 16 5 I/O TTL RE1/OE 12 13 4 17 6 I/O TTL RE2/WR 13 14 5 18 7 I/O TTL RE3/CAP4 14 15 6 19 8 I/O ST RF0/AN4 RF1/AN5 RF2/AN6 26 25 24 28 27 26 18 17 16 36 35 30 24 23 18 I/O I/O I/O ST ST ST RF0 can also be analog input 4. RF1 can also be analog input 5. RF2 can also be analog input 6. RF3/AN7 RF4/AN8 23 22 25 24 15 14 29 28 17 16 I/O I/O ST ST RF3 can also be analog input 7. RF4 can also be analog input 8. RF5/AN9 RF6/AN10 RF7/AN11 21 20 19 23 22 21 13 12 11 27 26 25 15 14 13 I/O I/O I/O ST ST ST RF5 can also be analog input 9. RF6 can also be analog input 10. RF7 can also be analog input 11. Description PORTC is a bi-directional I/O Port. 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. PORTD is a bi-directional I/O Port. Legend: I = Input only; P = Power; O = Output only; — = Not Used; I/O = Input/Output; TTL = TTL input; 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. PORTE is a bi-directional I/O Port. 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. 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. 1998 Microchip Technology Inc. DS30289A-page 13 PIC17C7XX TABLE 3-1: PINOUT DESCRIPTIONS PIC17C75X Name PIC17C76X DIP No. PLCC No. TQFP No. PLCC No. QFP No. I/O/P Type Buffer Type RG0/AN3 RG1/AN2 32 31 34 33 24 23 42 41 30 29 I/O I/O ST ST RG0 can also be analog input 3. RG1 can also be analog input 2. RG2/AN1/VREF- 30 32 22 40 28 I/O ST RG3/AN0/VREF+ 29 31 21 39 27 I/O ST RG4/CAP3 35 38 27 46 33 I/O ST 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/PWM3 36 39 28 47 34 I/O ST RG6/RX2/DT2 38 41 30 49 36 I/O ST RG7/TX2/CK2 37 40 29 48 35 I/O ST RH0 — — — 10 79 I/O ST RH1 — — — 11 80 I/O ST RH2 RH3 RH4/AN12 — — — — — — — — — 12 13 31 1 2 19 I/O I/O I/O ST ST ST RH4 can also be analog input 12. RH5/AN13 RH6/AN14 RH7/AN15 — — — — — — — — — 32 33 34 20 21 22 I/O I/O I/O ST ST ST RH5 can also be analog input 13. RH6 can also be analog input 14. RH7 can also be analog input 15. Description PORTG is a bi-directional I/O Port. 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 PORTJ is a bi-directional I/O Port. PORTJ is only available on the PIC17C76X devices. RJ0 — — — 52 39 I/O ST RJ1 — — — 53 40 I/O ST RJ2 RJ3 RJ4 — — — — — — — — — 54 55 73 41 42 59 I/O I/O I/O ST ST ST RJ5 RJ6 — — — — — — 74 75 60 61 I/O I/O ST ST RJ7 TEST — 16 — 17 — 8 76 21 62 10 I/O I ST ST VSS VDD AVSS 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 30 20 38 26 AVDD 27 29 19 37 25 NC — 1, 18, 35, 52 — 1, 22, 43, 64 — Legend: I = Input only; P = Power; O = Output only; — = Not Used; P Test mode selection control input. Always tie to VSS for normal operation. Ground reference for logic and I/O pins. P Positive supply for logic and I/O pins. P 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. P I/O = Input/Output; 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. DS30289A-page 14 1998 Microchip Technology Inc. PIC17C7XX 4.0 ON-CHIP OSCILLATOR CIRCUIT 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) 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. 4.1.2 CRYSTAL OSCILLATOR / CERAMIC RESONATORS 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 20 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. 4.1.2.1 OSCILLATOR / RESONATOR START-UP 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) 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. 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 Oscillator Configurations FIGURE 4-1: 4.1.1 OSCILLATOR TYPES OSCILLATOR / RESONATOR START-UP CHARACTERISTICS • • • • LF XT EC RC Low Power Crystal Crystal/Resonator External Clock Input Resistor/Capacitor VDD 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: 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. 1998 Microchip Technology Inc. Crystal Start-up Time Time DS30289A-page 15 PIC17C7XX FIGURE 4-2: CRYSTAL OR CERAMIC RESONATOR OPERATION (XT OR LF OSC CONFIGURATION) FIGURE 4-3: CRYSTAL OPERATION, OVERTONE CRYSTALS (XT OSC CONFIGURATION) C1 OSC1 OSC1 SLEEP C1 XTAL C2 SLEEP RF OSC2 OSC2 C3 Note1 To internal logic 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. TABLE 4-1: CAPACITOR SELECTION FOR CERAMIC RESONATORS Oscillator Type Resonator Frequency Capacitor Range C1 = C2 (1) LF 455 kHz 2.0 MHz 4.0 MHz 8.0 MHz 16.0 MHz 15 - 68 pF 10 - 33 pF 22 - 68 pF 33 - 100 pF 33 - 100 pF XT 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% Resonators used did not have built-in capacitors. PIC17CXXX 0.1 µF To filter the fundamental frequency 1 = (2πf)2 L*C2 Where f = tank circuit resonant frequency. This should be midway between the fundamental and the 3rd overtone frequencies of the crystal. C3 handles current during charging of tank circuit. TABLE 4-2: Osc Type LF XT CAPACITOR SELECTION FOR CRYSTAL OSCILLATOR Freq C1 (3) C2 (3) 32 kHz(1) 1 MHz 2 MHz 2 MHz 4 MHz 8 MHz (2) 16 MHz 25 MHz 32 MHz (3) 100-150 pF 10-33 pF 10-33 pF 47-100 pF 15-68 pF 15-47 pF TBD 15-47 pF 10 pF 100-150 pF 10-33 pF 10-33 pF 47-100 pF 15-68 pF 15-47 pF TBD 15-47 pF 10 pF 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: For VDD > 4.5V, C1 = C2 ≈ 30 pF is recommended. 2: RS of 330Ω is required for a capacitor combination of 15/15 pF. 3: 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 DS30289A-page 16 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 TBD ± 50 PPM ± 50 PPM 1998 Microchip Technology Inc. PIC17C7XX 4.1.3 EXTERNAL CLOCK OSCILLATOR 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). FIGURE 4-4: Clock from EXTERNAL CLOCK INPUT OPERATION (EC OSC CONFIGURATION) OSC1 ext. system CLKOUT (FOSC/4) PIC17CXXX OSC2 4.1.4 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 kΩ resistor provides the negative feedback for stability. The 10 kΩ potentiometer biases the 74AS04 in the linear region. This could be used for external oscillator designs. FIGURE 4-5: EXTERNAL PARALLEL RESONANT CRYSTAL OSCILLATOR CIRCUIT +5V To Other Devices 10 kΩ 4.7 kΩ 74AS04 PIC17CXXX OSC1 74AS04 10 kΩ XTAL 10kΩ 20 pF 20 pF 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 180-degree phase shift in a series resonant oscillator circuit. The 330 Ω resistors provide the negative feedback to bias the inverters in their linear region. FIGURE 4-6: EXTERNAL SERIES RESONANT CRYSTAL OSCILLATOR CIRCUIT 330 Ω 330 Ω 74AS04 74AS04 To Other Devices 74AS04 PIC17CXXX OSC1 0.1 µF XTAL 1998 Microchip Technology Inc. DS30289A-page 17 PIC17C7XX 4.1.5 RC OSCILLATOR 4.1.5.1 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 kΩ, the oscillator operation may become unstable, or stop completely. For very high Rext values (e.g. 1 MΩ), the oscillator becomes sensitive to noise, humidity and leakage. Thus, we recommend to keep Rext between 3 kΩ and 100 kΩ. 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 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). FIGURE 4-7: RC OSCILLATOR MODE VDD PIC17CXXX Rext OSC1 Internal clock Cext VSS OSC2/CLKOUT Fosc/4 DS30289A-page 18 1998 Microchip Technology Inc. PIC17C7XX 4.2 Clocking Scheme/Instruction Cycle 4.3 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. 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). FIGURE 4-8: CLOCK/INSTRUCTION CYCLE Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 Q1 Q2 Internal phase clock Q3 Q4 PC OSC2/CLKOUT (RC mode) EXAMPLE 4-1: PC Fetch INST (PC) Execute INST (PC-1) PC+2 Fetch INST (PC+1) Execute INST (PC) Fetch INST (PC+2) Execute INST (PC+1) INSTRUCTION PIPELINE FLOW 1. MOVLW 55h TCY0 TCY1 Fetch 1 Execute 1 2. MOVWF PORTB 3. CALL SUB_1 4. BSF PC+1 PORTA, BIT3 (Forced NOP) 5. Instruction @ address SUB_1 Fetch 2 TCY2 TCY3 TCY4 TCY5 Execute 2 Fetch 3 Execute 3 Fetch 4 Flush Fetch SUB_1 Execute 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. 1998 Microchip Technology Inc. DS30289A-page 19 PIC17C7XX NOTES: DS30289A-page 20 1998 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 Note: 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. FIGURE 5-1: When the device enters the "reset state" the Data Direction registers (DDR) are forced set, which will make the I/O hi-impendance inputs. The reset state of some peripheral modules may force the I/O to other operations, such as analog inputs or the system bus. 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. A simplified block diagram of the on-chip reset circuit is shown in Figure 5-1. SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT External Reset MCLR BOR Module Brown-out Reset WDT Module WDT Time_Out Reset VDD rise detect S Power_On_Reset VDD OST/PWRT Chip_Reset Q R OST 10-bit Ripple counter OSC1 PWRT † This RC oscillator is shared with the WDT when not in a power-up sequence. 1998 Microchip Technology Inc. Enable PWRT 10-bit Ripple counter Enable OST On-chip RC OSC† (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) DS30289A-page 21 PIC17C7XX 5.1 5.1.1 Power-on Reset (POR), Power-up Timer (PWRT), Oscillator Start-up Timer (OST), and Brown-out Reset (BOR) POWER-ON RESET (POR) 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. FIGURE 5-2: USING ON-CHIP POR VDD VDD MCLR PIC17CXXX FIGURE 5-3: EXTERNAL POWER-ON RESET CIRCUIT (FOR SLOW VDD POWER-UP) VDD VDD D 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. 5.1.3 OSCILLATOR START-UP TIMER (OST) 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. FIGURE 5-4: OSCILLATOR START-UP TIME (LOW FREQ) POR or BOR Trip Point R VDD R1 MCLR C PIC17CXXX MCLR OSC2 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 kΩ 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 µA). A larger voltage drop will degrade VIH level on the MCLR/VPP pin. 3: R1 = 100Ω to 1 kΩ 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). DS30289A-page 22 TOSC1 TOST 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. 1998 Microchip Technology Inc. PIC17C7XX 5.1.4 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. 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 5-6 display these time-out sequences. TABLE 5-1: 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. TIME-OUT IN VARIOUS SITUATIONS Oscillator Configuration POR, BOR Wake up from SLEEP MCLR Reset XT, LF Greater of: 96 ms or 1024TOSC 1024TOSC — EC, RC Greater of: 96 ms or 1024TOSC — — TABLE 5-2: STATUS BITS AND THEIR SIGNIFICANCE POR BOR (1) TO PD 0 0 1 1 Power-on Reset 1 1 1 0 MCLR Reset during SLEEP or interrupt wake-up from SLEEP 1 1 0 1 WDT Reset during normal operation 1 1 0 0 WDT Wake-up during SLEEP 1 1 1 1 MCLR Reset during normal operation 1 0 1 1 Brown-out Reset 0 0 0 x Illegal, TO is set on POR 0 0 x 0 Illegal, PD is set on POR x x 1 1 CLRWDT instruction executed Event 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 PCH:PCL CPUSTA (4) OST Active Power-on Reset 0000h --11 1100 Yes Brown-out Reset 0000h --11 1110 Yes MCLR Reset during normal operation 0000h --11 1111 No MCLR Reset during SLEEP 0000h --11 1011 Yes (2) Event WDT Reset during normal operation 0000h --11 0111 No WDT Wake-up during SLEEP (3) 0000h --11 0011 Yes (2) PC + 1 --11 1011 Yes (2) PC + 1 (1) --10 1011 Yes (2) Interrupt wake-up from SLEEP GLINTD is set GLINTD is clear 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. This is different from the mid-range devices. 4: When BODEN is enabled, else the BOR status bit is unknown. 1998 Microchip Technology Inc. DS30289A-page 23 PIC17C7XX In Figure 5-5, Figure 5-6 and Figure 5-7, the TPWRT timer timeout is greater then the TOST timer timeout, 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: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD) VDD MCLR INTERNAL POR 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 1V 0V MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET DS30289A-page 24 1998 Microchip Technology Inc. PIC17C7XX TABLE 5-4: Register INITIALIZATION CONDITIONS FOR SPECIAL FUNCTION REGISTERS Address Power-on Reset Brown-out Reset MCLR Reset WDT Reset Wake-up from SLEEP through interrupt Unbanked INDF0 00h N.A. N.A. N.A. FSR0 01h xxxx xxxx uuuu uuuu uuuu uuuu PCL 02h 0000h 0000h PC + 1(2) PCLATH 03h 0000 0000 uuuu uuuu uuuu uuuu ALUSTA 04h 1111 xxxx 1111 uuuu 1111 uuuu T0STA 05h 0000 000- 0000 000- 0000 000- CPUSTA 06h --11 11qq --11 qquu --uu qquu INTSTA 07h 0000 0000 0000 0000 uuuu uuuu(1) INDF1 08h N.A. N.A. N.A. FSR1 09h xxxx xxxx uuuu uuuu uuuu uuuu WREG 0Ah xxxx xxxx uuuu uuuu uuuu uuuu TMR0L 0Bh xxxx xxxx uuuu uuuu uuuu uuuu TMR0H 0Ch xxxx xxxx uuuu uuuu uuuu uuuu TBLPTRL 0Dh 0000 0000 0000 0000 uuuu uuuu TBLPTRH 0Eh 0000 0000 0000 0000 uuuu uuuu BSR 0Fh 0000 0000 0000 0000 uuuu uuuu (3) Bank 0 PORTA (4,6) 10h 0-xx 11xx 0-uu 11uu u-uu uuuu DDRB 11h 1111 1111 1111 1111 uuuu uuuu PORTB (4) 12h xxxx xxxx uuuu uuuu uuuu uuuu RCSTA1 13h 0000 -00x 0000 -00u uuuu -uuu RCREG1 14h xxxx xxxx uuuu uuuu uuuu uuuu TXSTA1 15h 0000 --1x 0000 --1u uuuu --uu TXREG1 16h xxxx xxxx uuuu uuuu uuuu uuuu SPBRG1 17h 0000 0000 0000 0000 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 externded microcontroller mode, the operation of this port does not rely on these registers 6: On any device reset, these pins are configured as inputs. 1998 Microchip Technology Inc. DS30289A-page 25 PIC17C7XX TABLE 5-4: Register INITIALIZATION CONDITIONS FOR SPECIAL FUNCTION REGISTERS MCLR Reset WDT Reset (Cont.’d) Wake-up from SLEEP through interrupt Address Power-on Reset Brown-out Reset 10h 1111 1111 1111 1111 uuuu uuuu Bank 1 DDRC (5) PORTC (4, 5) DDRD (5) 11h xxxx xxxx uuuu uuuu uuuu uuuu 12h 1111 1111 1111 1111 uuuu uuuu 13h xxxx xxxx uuuu uuuu uuuu uuuu 14h ---- 1111 ---- 1111 ---- uuuu PORTE (4, 5) 15h ---- xxxx ---- uuuu ---- uuuu PIR1 16h x000 0010 u000 0010 uuuu uuuu(1) PIE1 17h 0000 0000 0000 0000 uuuu uuuu TMR1 10h xxxx xxxx uuuu uuuu uuuu uuuu TMR2 11h xxxx xxxx uuuu uuuu uuuu uuuu TMR3L 12h xxxx xxxx uuuu uuuu uuuu uuuu TMR3H 13h xxxx xxxx uuuu uuuu uuuu uuuu PR1 14h xxxx xxxx uuuu uuuu uuuu uuuu PR2 15h xxxx xxxx uuuu uuuu uuuu uuuu PR3/CA1L 16h xxxx xxxx uuuu uuuu uuuu uuuu PR3/CA1H 17h xxxx xxxx uuuu uuuu uuuu uuuu PORTD (4, 5) DDRE (5) Bank 2 Bank 3 PW1DCL 10h xx-- ---- uu-- ---- uu-- ---- PW2DCL 11h xx0- ---- uu0- ---- uuu- ---- PW1DCH 12h xxxx xxxx uuuu uuuu uuuu uuuu PW2DCH 13h xxxx xxxx uuuu uuuu uuuu uuuu CA2L 14h xxxx xxxx uuuu uuuu uuuu uuuu CA2H 15h xxxx xxxx uuuu uuuu uuuu uuuu TCON1 16h 0000 0000 0000 0000 uuuu uuuu TCON2 17h 0000 0000 0000 0000 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 externded microcontroller mode, the operation of this port does not rely on these registers 6: On any device reset, these pins are configured as inputs. DS30289A-page 26 1998 Microchip Technology Inc. PIC17C7XX TABLE 5-4: INITIALIZATION CONDITIONS FOR SPECIAL FUNCTION REGISTERS MCLR Reset WDT Reset (Cont.’d) Wake-up from SLEEP through interrupt Address Power-on Reset Brown-out Reset 10h 000- 0010 000- 0010 uuu- uuuu(1) PIE2 11h 000- 0000 000- 0000 uuu- uuuu Unimplemented 12h ---- ---- RCSTA2 13h RCREG2 TXSTA2 TXREG2 SPBRG2 Register Bank 4 PIR2 ---- ---- ---- ---- 0000 -00x 0000 -00u uuuu -uuu 14h xxxx xxxx uuuu uuuu uuuu uuuu 15h 0000 --1x 0000 --1u uuuu --uu 16h xxxx xxxx uuuu uuuu uuuu uuuu 17h 0000 0000 0000 0000 uuuu uuuu DDRF 10h 1111 1111 1111 1111 uuuu uuuu PORTF (4) 11h 0000 0000 0000 0000 uuuu uuuu DDRG 12h 1111 1111 1111 1111 uuuu uuuu 13h xxxx 0000 uuuu 0000 uuuu uuuu Bank 5 PORTG (4) ADCON0 14h 0000 -0-0 0000 -0-0 uuuu uuuu ADCON1 15h 000- 0000 000- 0000 uuuu uuuu ADRESL 16h xxxx xxxx uuuu uuuu uuuu uuuu ADRESH 17h xxxx xxxx uuuu uuuu uuuu uuuu SSPADD 10h 0000 0000 0000 0000 uuuu uuuu SSPCON1 11h 0000 0000 0000 0000 uuuu uuuu SSPCON2 12h 0000 0000 0000 0000 uuuu uuuu SSPSTAT 13h 0000 0000 0000 0000 uuuu uuuu SSPBUF 14h xxxx xxxx uuuu uuuu uuuu uuuu Unimplemented 15h ---- ---- ---- ---- ---- ---- Unimplemented 16h ---- ---- ---- ---- ---- ---- Unimplemented 17h ---- ---- ---- ---- ---- ---- Bank 6 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 externded microcontroller mode, the operation of this port does not rely on these registers 6: On any device reset, these pins are configured as inputs. 1998 Microchip Technology Inc. DS30289A-page 27 PIC17C7XX TABLE 5-4: Register INITIALIZATION CONDITIONS FOR SPECIAL FUNCTION REGISTERS Address Power-on Reset Brown-out Reset MCLR Reset WDT Reset (Cont.’d) Wake-up from SLEEP through interrupt Bank 7 PW3DCL 10h xx0- ---- PW3DCH 11h xxxx xxxx uu0- ---- uuu- ---- uuuu uuuu uuuu uuuu CA3L 12h xxxx xxxx uuuu uuuu uuuu uuuu CA3H 13h xxxx xxxx uuuu uuuu uuuu uuuu CA4L 14h xxxx xxxx uuuu uuuu uuuu uuuu CA4H 15h xxxx xxxx uuuu uuuu uuuu uuuu TCON3 16h -000 0000 -000 0000 -uuu uuuu Unimplemented 17h ---- ---- ---- ---- ---- ---- DDRH 10h 1111 1111 1111 1111 uuuu uuuu PORTH (4) 11h xxxx xxxx uuuu uuuu uuuu uuuu DDRJ 12h 1111 1111 1111 1111 uuuu uuuu PORTJ (4) 13h xxxx xxxx uuuu uuuu uuuu uuuu PRODL 18h xxxx xxxx uuuu uuuu uuuu uuuu PRODH 19h xxxx xxxx uuuu uuuu uuuu uuuu Bank 8 Unbanked 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 externded microcontroller mode, the operation of this port does not rely on these registers 6: On any device reset, these pins are configured as inputs. DS30289A-page 28 1998 Microchip Technology Inc. PIC17C7XX 5.1.5 FIGURE 5-8: 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: EXTERNAL BROWN-OUT PROTECTION CIRCUIT 1 VDD VDD 33k 10kΩ MCLR 40 kΩ Before using the on-chip brown-out for a voltage supervisory function, please review the electrical specifications to ensure that they meet your requirements. PIC17CXXX This circuit will activate reset when VDD goes below (Vz + 0.7V) where Vz = Zener voltage. The BODEN configuration bit can disable (if clear/programmed) or enable (if set) the Brown-out Reset circuitry. If VDD falls below BVDD (Typically 4.0V, parameter #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 parameter #35. The chip will remain in Brown-out Reset until VDD rises above BVDD. The Power-up Timer and Oscillator Start-up 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 Start-up 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. FIGURE 5-9: EXTERNAL BROWN-OUT PROTECTION CIRCUIT 2 VDD VDD R1 Q1 MCLR R2 40 kΩ 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 • 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 that may be implemented. Each needs to be evaluated to determine if they match the requirements of the application. R1 R1 + R2 = 0.7V FIGURE 5-10: BROWN-OUT SITUATIONS VDD Internal Reset BVDD Max. BVDD Min. Greater of 96 ms and 1024 Tosc VDD Internal Reset BVDD Max. BVDD Min. < 96 ms Greater of 96 ms and 1024 Tosc VDD Internal Reset 1998 Microchip Technology Inc. BVDD Max. BVDD Min. Greater of 96 ms and 1024 Tosc DS30289A-page 29 PIC17C7XX NOTES: DS30289A-page 30 1998 Microchip Technology Inc. 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 There are six registers used in the control and status of interrupts. These are: • • • • • • CPUSTA INTSTA PIE1 PIR1 PIE2 PIR2 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 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: 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). INTERRUPT LOGIC PIR1 / PIE1 RBIF RBIE TMR3IF TMR3IE TMR2IF TMR2IE TMR1IF TMR1IE CA2IF CA2IE CA1IF CA1IE INTF INTE TX1IF TX1IE RC1IF RC1IE SSPIF SSPIE PIR2 / PIE2 INTSTA T0IF T0IE Wake-up (If in SLEEP mode) or terminate long write Interrupt to CPU T0CKIF T0CKIE PEIF PEIE BCLIF BCLIE GLINTD (CPUSTA<4>) ADIF ADIE CA4IF CA4IE CA3IF CA3IE TX2IF TX2IE RC2IF RC2IE 1998 Microchip Technology Inc. DS30289A-page 31 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 6-5 and Figure 6-6). 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). FIGURE 6-2: R-0 PEIF bit7 INTSTA REGISTER (ADDRESS: 07h, UNBANKED) R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 T0CKIF T0IF INTF PEIE T0CKIE T0IE INTE bit0 R = Readable bit W = Writable bit - n = Value at POR reset bit 7: 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 bit 6: 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 bit 5: 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 bit 4: 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 bit 3: 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 bit 2: 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 bit 1: T0IE: TMR0 Overflow Interrupt Enable bit 1 = Enable TMR0 overflow interrupt 0 = Disable TMR0 overflow interrupt bit 0: 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 DS30289A-page 32 1998 Microchip Technology Inc. PIC17C7XX 6.2 Peripheral Interrupt Enable Register1 (PIE1) and Register2 (PIE2) These registers contains the individual enable bits for the peripheral interrupts. FIGURE 6-3: PIE1 REGISTER (ADDRESS: 17h, BANK 1) R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 RBIE TMR3IE TMR2IE TMR1IE CA2IE CA1IE TX1IE RC1IE bit7 bit0 bit 7: RBIE: PORTB Interrupt on Change Enable bit 1 = Enable PORTB interrupt on change 0 = Disable PORTB interrupt on change bit 6: TMR3IE: TMR3 Interrupt Enable bit 1 = Enable TMR3 interrupt 0 = Disable TMR3 interrupt bit 5: TMR2IE: TMR2 Interrupt Enable bit 1 = Enable TMR2 interrupt 0 = Disable TMR2 interrupt bit 4: TMR1IE: TMR1 Interrupt Enable bit 1 = Enable TMR1 interrupt 0 = Disable TMR1 interrupt bit 3: CA2IE: Capture2 Interrupt Enable bit 1 = Enable Capture2 interrupt 0 = Disable Capture2 interrupt bit 2: CA1IE: Capture1 Interrupt Enable bit 1 = Enable Capture1 interrupt 0 = Disable Capture1 interrupt bit 1: TX1IE: USART1 Transmit Interrupt Enable bit 1 = Enable USART1 Transmit buffer empty interrupt 0 = Disable USART1 Transmit buffer empty interrupt bit 0: RC1IE: USART1 Receive Interrupt Enable bit 1 = Enable USART1 Receive buffer full interrupt 0 = Disable USART1 Receive buffer full interrupt 1998 Microchip Technology Inc. R = Readable bit W = Writable bit -n = Value at POR reset DS30289A-page 33 PIC17C7XX FIGURE 6-4: PIE2 REGISTER (ADDRESS: 11h, BANK 4) R/W - 0 R/W - 0 SSPIE BCLIE bit7 R/W - 0 ADIE U-0 — R/W - 0 CA4IE R/W - 0 CA3IE bit 7: SSPIE: Synchronous Serial Port Interrupt Enable bit 1 = Enable SSP Interrupt 0 = Disable SSP Interrupt bit 6: BCLIE: Bus Collision Interrupt Enable bit 1 = Enable Bus Collision Interrupt 0 = Disable Bus Collision Interrupt bit 5: ADIE: A/D Module Interrupt Enable bit 1 = Enable A/D Module Interrupt 0 = Disable A/D Module Interrupt bit 4: Unimplemented: Read as ‘0’ bit 3: CA4IE: Capture4 Interrupt Enable bit 1 = Enable Capture4 Interrupt 0 = Disable Capture4 Interrupt bit 2: CA3IE: Capture3 Interrupt Enable bit 1 = Enable Capture3 Interrupt 0 = Disable Capture3 Interrupt bit 1: TX2IE: USART2 Transmit Interrupt Enable bit 1 = Enable USART2 Transmit Buffer Empty Interrupt 0 = Disable USART2 Transmit Buffer Empty Interrupt bit 0: RC2IE: USART2 Receive Interrupt Enable bit 1 = Enable USART2 Receive Buffer Full Interrupt 0 = Disable USART2 Receive Buffer Full Interrupt DS30289A-page 34 R/W - 0 TX2IE R/W - 0 RC2IE bit0 R = Readable bit W = Writable bit -n = Value at POR reset 1998 Microchip Technology Inc. PIC17C7XX 6.3 Peripheral Interrupt Request Register1 (PIR1) and Register2 (PIR2) Note: These registers contains the individual flag bits for the peripheral interrupts. FIGURE 6-5: 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. PIR1 REGISTER (ADDRESS: 16h, BANK 1) R/W - x R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R - 1 R - 0 RBIF TMR3IF TMR2IF TMR1IF CA2IF CA1IF TX1IF RC1IF bit7 bit0 R = Readable bit W = Writable bit -n = Value at POR reset 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 bit 6: 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 bit 4: 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 bit 2: CA1IF: Capture1 Interrupt Flag bit 1 = Capture event occurred on RB0/CAP1 pin 0 = Capture event did not occur on RB0/CAP1 pin bit 1: TX1IF: USART1 Transmit Interrupt Flag bit (State controlled by hardware) 1 = USART1 Transmit buffer is empty 0 = USART1 Transmit buffer is full bit 0: RC1IF: USART1 Receive Interrupt Flag bit (State controlled by hardware) 1 = USART1 Receive buffer is full 0 = USART1 Receive buffer is empty 1998 Microchip Technology Inc. DS30289A-page 35 PIC17C7XX FIGURE 6-6: PIR2 REGISTER (ADDRESS: 10h, BANK 4) R/W - 0 R/W - 0 SSPIF BCLIF bit7 R/W - 0 ADIF U-0 — R/W - 0 CA4IF R/W - 0 CA3IF R-1 TX2IF R-0 RC2IF bit0 R = Readable bit W = Writable bit -n = Value at POR reset bit 7: 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. I2C Slave / Master A transmission/reception has taken place. I2C 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 (Multimaster system). A stop condition occurred while the SSP module was idle (Multimaster 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 bit 5: ADIF: A/D Module Interrupt Flag bit 1 = An A/D conversion is complete 0 = An A/D conversion is not complete bit 4: Unimplemented: Read as '0' bit 3: CA4IF: Capture4 Interrupt Flag bit 1 = Capture event occurred on RE3/CAP4 pin 0 = Capture event did not occur on RE3/CAP4 pin bit 2: CA3IF: Capture3 Interrupt Flag bit 1 = Capture event occurred on RG4/CAP3 pin 0 = Capture event did not occur on RG4/CAP3 pin bit 1: TX2IF:USART2 Transmit Interrupt Flag bit (State controlled by hardware) 1 = USART2 Transmit buffer is empty 0 = USART2 Transmit buffer is full bit 0: RC2IF: USART2 Receive Interrupt Flag bit (State controlled by hardware) 1 = USART2 Receive buffer is full 0 = USART2 Receive buffer is empty DS30289A-page 36 1998 Microchip Technology Inc. PIC17C7XX 6.4 Interrupt Operation 6.5 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 re-enabling interrupts to avoid continuous interrupts. RA0/INT Interrupt 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 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 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’ed 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. TABLE 6-1: 6.8 Address 0008h 0010h 0018h 0020h INTERRUPT VECTORS/PRIORITIES Vector External Interrupt on RA0/INT pin (INTF) TMR0 overflow interrupt (T0IF) External Interrupt on T0CKI (T0CKIF) Peripherals (PEIF) Priority 1 (Highest) 2 3 4 (Lowest) Note 1: Individual interrupt flag bits are set regardless of the status of their corresponding mask bit or the GLINTD bit. Note 2: Before disabling any of the INTSTA enable bits, the GLINTD bit should be set (disabled). Context Saving During Interrupts 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. 1998 Microchip Technology Inc. DS30289A-page 37 DS30289A-page 38 Instruction executed System Bus Instruction Fetched PC GLINTD INTF or T0CKIF RA0/INT or RA1/T0CKI PC PC Inst (PC) Inst (PC) Addr Inst (PC+1) PC + 1 Dummy Addr Inst (PC+1) Dummy Addr Inst (Vector) Addr (Vector) Addr YY RETFIE RETFIE Addr Inst (YY + 1) YY + 1 Dummy PC + 1 FIGURE 6-7: OSC2 OSC1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 PIC17C7XX INT PIN / T0CKI PIN INTERRUPT TIMING 1998 Microchip Technology Inc. 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) 1998 Microchip Technology Inc. DS30289A-page 39 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) DS30289A-page 40 1998 Microchip Technology Inc. PIC17C7XX 7.0 MEMORY ORGANIZATION 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. FIGURE 7-1: PROGRAM MEMORY MAP AND STACK PC<15:0> 16 CALL, RETURN RETFIE, RETLW Stack Level 1 • • • Stack Level 16 Reset Vector 0000h 0008h Timer0 Interrupt Vector 0010h 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). T0CKI Pin Interrupt Vector 0018h Peripheral Interrupt Vector 0020h 0021h 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: 1FFFh (PIC17C752 PIC17C762) Microprocessor Microcontroller Extended Microcontroller Protected Microcontroller 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. 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. 3FFFh (PIC17C756A PIC17C766) Configuration Memory Space • • • • User Memory Space (1) INT Pin Interrupt Vector Program Memory Organization 7.1 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. 1998 Microchip Technology Inc. FOSC0 FOSC1 WDTPS0 WDTPS1 PM0 Reserved PM1 Reserved Reserved BODEN PM2 Test EPROM FDFFh FE00h FE01h FE02h FE03h FE04h FE05h FE06h FE07h FE08h FE0Dh FE0Eh FE0Fh FE10h FF5Fh FF60h Boot ROM FFFFh Note 1: User memory space may be internal, external, or both. The memory configuration depends on the processor mode. DS30289A-page 41 PIC17C7XX MODE MEMORY ACCESS Operating Mode Internal Program Memory Configuration Bits, Test Memory, Boot ROM Microprocessor No Access No Access Microcontroller Access Access Extended Microcontroller Access No Access Protected Microcontroller Access Access Regardless of the processor mode, data memory is always on-chip. MEMORY MAP IN DIFFERENT MODES Extended Microcontroller Mode Microcontroller Modes 0000h 0000h 01FFFh On-chip Program Memory 01FFFh 2000h 2000h External Program Memory External Program Memory PIC17C752/762 FE00h Config. Bits Test Memory FFFFh Boot ROM FFFFh FFFFh OFF-CHIP ON-CHIP OFF-CHIP ON-CHIP 00h FFh OFF-CHIP ON-CHIP 00h 120h 00h 120h 1FFh FFh ON-CHIP 120h 1FFh FFh ON-CHIP 0000h On-chip Program Memory 3FFFh 4000h 3FFFh External Program Memory 1FFh ON-CHIP 0000h 0000h On-chip Program Memory 4000h External Program Memory PIC17C756A/766 FE00h Config. Bits Test Memory FFFFh Boot ROM FFFFh FFFFh OFF-CHIP ON-CHIP 00h OFF-CHIP FFh ON-CHIP 1FFh 2FFh 3FFh ON-CHIP OFF-CHIP 120h 220h 320h 120h 220h 320h FFh ON-CHIP 00h 00h 120h 220h 320h DS30289A-page 42 On-chip Program Memory PROGRAM SPACE 0000h DATA SPACE Microprocessor Mode PROGRAM SPACE FIGURE 7-2: 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. 1FFh 2FFh 3FFh ON-CHIP FFh 1FFh 2FFh 3FFh ON-CHIP DATA SPACE TABLE 7-1: 1998 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. FIGURE 7-3: Q1 AD <15:0> Q2 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. This 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: EXTERNAL PROGRAM MEMORY ACCESS WAVEFORMS Q4 Q3 Address out Data in Q1 Q2 Q3 Address out Q1 Q4 Data out EPROM MEMORY ACCESS TIME ORDERING SUFFIX PIC17C7XX Oscillator Frequency Instruction Cycle Time (TCY) EPROM Suffix 8 MHz 500 ns -25 16 MHz 250 ns -15 20 MHz 200 ns -10 25 MHz 160 ns -70 33 MHz 121 ns (1) ALE OE '1' WR Read cycle Write cycle 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. FIGURE 7-4: Note 1: 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. TYPICAL EXTERNAL PROGRAM MEMORY CONNECTION DIAGRAM AD15-AD0 A15-A0 AD7-AD0 373(3) PIC17CXXX AD15-AD8 Memory(3) (MSB) Memory(3) (LSB) Ax-A0 Ax-A0 D7-D0 D7-D0 CE CE OE WR (2) OE WR(2) 373(3) ALE 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. 1998 Microchip Technology Inc. DS30289A-page 43 PIC17C7XX 7.2 Data Memory Organization 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) (Section 7.4). Indirect addressing uses the appropriate control bits of the BSR for accesses into the banked areas of data memory. The BSR is explained in greater detail in Section 7.8. DS30289A-page 44 7.2.1 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 Power-on 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. 1998 Microchip Technology Inc. PIC17C7XX FIGURE 7-5: Addr Unbanked 00h 01h 02h 03h 04h 05h 06h 07h 08h 09h 0Ah 0Bh 0Ch 0Dh 0Eh 0Fh INDF0 10h 11h 12h 13h 14h 15h 16h 17h PIC17C7XX REGISTER FILE MAP FSR0 PCL PCLATH ALUSTA T0STA CPUSTA INTSTA INDF1 FSR1 WREG TMR0L TMR0H TBLPTRL TBLPTRH BSR Bank 0 Bank 1 (1) Bank 2 (1) Bank 3 (1) Bank 4 (1) Bank 5 (1) Bank 6 (1) Bank 7 (1) PORTA DDRC TMR1 PW1DCL PIR2 DDRF SSPADD PW3DCL Bank 8 (1, 4) DDRH DDRB PORTC TMR2 PW2DCL PIE2 PORTF SSPCON1 PW3DCH PORTH PORTB DDRD TMR3L PW1DCH — DDRG SSPCON2 CA3L DDRJ RCSTA1 PORTD TMR3H PW2DCH RCSTA2 PORTG SSPSTAT CA3H PORTJ RCREG1 DDRE PR1 CA2L RCREG2 ADCON0 SSPBUF CA4L — TXSTA1 PORTE PR2 CA2H TXSTA2 ADCON1 — CA4H — TXREG1 PIR1 PR3L/CA1L TCON1 TXREG2 ADRESL — TCON3 — SPBRG1 PIE1 PR3H/CA1H TCON2 SPBRG2 ADRESH — — — Bank 0 (2) Bank 1 (2) Bank 2 (2, 3) Bank 3 (2, 3) General Purpose RAM General Purpose RAM General Purpose RAM General Purpose RAM Unbanked 18h 19h 1Ah 1Fh PRODL PRODH General Purpose RAM 20h 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. 1998 Microchip Technology Inc. DS30289A-page 45 PIC17C7XX TABLE 7-3: SPECIAL FUNCTION REGISTERS Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR MCLR, WDT Unbanked 00h INDF0 Uses contents of FSR0 to address data memory (not a physical register) ---- ---- ---- ---- 01h FSR0 Indirect data memory address pointer 0 xxxx xxxx uuuu uuuu 02h PCL Low order 8-bits of PC 0000 0000 0000 0000 03h(1) PCLATH Holding register for upper 8-bits of PC 04h ALUSTA 05h T0STA (2) 0000 0000 uuuu uuuu FS3 FS2 FS1 FS0 OV Z DC C INTEDG T0SE T0CS T0PS3 T0PS2 T0PS1 T0PS0 — 0000 000- 0000 000- — — STKAV GLINTD TO PD POR BOR --11 11qq --11 qquu PEIF T0CKIF T0IF INTF PEIE T0CKIE T0IE INTE 0000 0000 0000 0000 1111 xxxx 1111 uuuu 06h CPUSTA 07h INTSTA 08h INDF1 Uses contents of FSR1 to address data memory (not a physical register) ---- ---- ---- ---- 09h FSR1 Indirect data memory address pointer 1 xxxx xxxx uuuu uuuu 0Ah WREG Working register xxxx xxxx uuuu uuuu 0Bh TMR0L TMR0 register; low byte xxxx xxxx uuuu uuuu 0Ch TMR0H TMR0 register; high byte xxxx xxxx uuuu uuuu 0Dh TBLPTRL Low byte of program memory table pointer 0000 0000 0000 0000 0Eh TBLPTRH High byte of program memory table pointer 0000 0000 0000 0000 0Fh BSR Bank select register 0000 0000 0000 0000 Bank 0 RA5/TX1/ CK1 RA4/RX1/ RA3/SDI/ DT1 SDA RA2/SS/ SCL RA1/T0CKI RA0/INT 0-xx 11xx 0-uu 11uu 10h PORTA (4,6) 11h DDRB 12h PORTB (4) 13h RCSTA1 14h RCREG1 15h TXSTA1 16h TXREG1 Serial Port Transmit Register (for USART1) xxxx xxxx uuuu uuuu 17h SPBRG1 Baud Rate Generator Register (for USART1) 0000 0000 0000 0000 DDRC (5) Data direction register for PORTC RBPU — Data direction register for PORTB 1111 1111 1111 1111 RB7/ SDO RB6/ SCK RB5/ TCLK3 RB4/ TCLK12 RB3/ PWM2 RB2/ PWM1 RB1/ CAP2 RB0/ CAP1 xxxx xxxx uuuu uuuu SPEN RX9 SREN CREN — FERR OERR RX9D 0000 -00x 0000 -00u SYNC — — TRMT TX9D 0000 --1x 0000 --1u Serial port receive register CSRC TX9 TXEN xxxx xxxx uuuu uuuu Bank 1 10h (4, 5) 11h PORTC 12h DDRD (5) (4, 5) 13h PORTD 14h DDRE (5) RC7/ AD7 RC6/ AD6 RC5/ AD5 1111 1111 1111 1111 RC4/ AD4 RC3/ AD3 RC2/ AD2 RC1/ AD1 RC0/ AD0 xxxx xxxx uuuu uuuu RD4/ AD12 RD3/ AD11 RD2/ AD10 RD1/ AD9 RD0/ AD8 xxxx xxxx uuuu uuuu 1111 1111 1111 1111 Data direction register for PORTD RD7/ AD15 RD6/ AD14 RD5/ AD13 ---- 1111 ---- 1111 Data direction register for PORTE 15h PORTE — — — — RE3/ CAP4 RE2/WR RE1/OE 16h PIR1 RBIF TMR3IF TMR2IF TMR1IF CA2IF CA1IF TX1IF RC1IF x000 0010 u000 0010 17h PIE1 RBIE TMR3IE TMR2IE TMR1IE CA2IE CA1IE TX1IE RC1IE 0000 0000 0000 0000 (4, 5) RE0/ALE ---- xxxx ---- uuuu Legend: x = unknown, u = unchanged,- = unimplemented read as '0',q - value depends on condition. Shaded cells are unimplemented, read as '0'. Note1: 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. DS30289A-page 46 1998 Microchip Technology Inc. PIC17C7XX TABLE 7-3: SPECIAL FUNCTION REGISTERS (Cont.’d) Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR MCLR, WDT Bank 2 10h TMR1 Timer1’s register xxxx xxxx uuuu uuuu 11h TMR2 Timer2’s register xxxx xxxx uuuu uuuu 12h TMR3L Timer3’s register; low byte xxxx xxxx uuuu uuuu 13h TMR3H Timer3’s register; high byte xxxx xxxx uuuu uuuu 14h PR1 Timer1’s period register xxxx xxxx uuuu uuuu 15h PR2 Timer2’s period register xxxx xxxx uuuu uuuu 16h PR3L/CA1L Timer3’s period register - low byte/capture1 register; low byte xxxx xxxx uuuu uuuu 17h PR3H/CA1H Timer3’s period register - high byte/capture1 register; high byte xxxx xxxx uuuu uuuu Bank 3 10h PW1DCL DC1 DC0 — — — — — — xx-- ---- uu-- ---- 11h PW2DCL DC1 DC0 TM2PW2 — — — — — xx0- ---- uu0- ---- 12h PW1DCH DC9 DC8 DC7 DC6 DC5 DC4 DC3 DC2 xxxx xxxx uuuu uuuu 13h PW2DCH DC9 DC8 DC7 DC6 DC5 DC4 DC3 DC2 xxxx xxxx uuuu uuuu 14h CA2L Capture2 low byte 15h CA2H Capture2 high byte 16h TCON1 CA2ED1 CA2ED0 17h TCON2 CA2OVF CA1OVF PWM2ON PWM1ON CA1/PR3 xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu CA1ED1 CA1ED0 T16 TMR3CS TMR2CS TMR1CS 0000 0000 0000 0000 TMR3ON TMR2ON TMR1ON 0000 0000 0000 0000 Bank 4: 10h PIR2 SSPIF BCLIF ADIF — CA4IF CA3IF TX2IF RC2IF 000- 0010 000- 0010 11h PIE2 SSPIE BCLIE ADIE — CA4IE CA3IE TX2IE RC2IE 000- 0000 000- 0000 12h Unimplemented — — — — — — — — ---- ---- ---- ---- 13h RCSTA2 SPEN RX9 SREN CREN — FERR OERR RX9D 0000 -00x 0000 -00u 14h RCREG2 15h TXSTA2 — — TRMT TX9D 0000 --1x 0000 --1u 16h TXREG2 Serial Port Transmit Register for USART2 xxxx xxxx uuuu uuuu 17h SPBRG2 Baud Rate Generator for USART2 0000 0000 0000 0000 10h DDRF Data Direction Register for PORTF 11h PORTF (4) 12h DDRG Data Direction Register for PORTG 13h PORTG (4) RG7/ RG6/ TX2/CK2 RX2/DT2 Serial Port Receive Register for USART2 CSRC TX9 TXEN SYNC xxxx xxxx uuuu uuuu Bank 5: RF7/ AN11 RF6/ AN10 RF5/ AN9 1111 1111 1111 1111 RF4/ AN8 RF3/ AN7 RF2/ AN6 RF1/ AN5 RF0/ AN4 RG5/ PWM3 RG4/ CAP3 RG3/ AN0 RG2/ AN1 RG1/ AN2 RG0/ AN3 0000 0000 0000 0000 1111 1111 1111 1111 xxxx 0000 uuuu 0000 14h ADCON0 CHS3 CHS2 CHS1 CHS0 — GO/DONE — ADON 0000 -0-0 0000 -0-0 15h ADCON1 ADCS1 ADCS0 ADFM — PCFG3 PCFG2 PCFG1 PCFG0 000- 0000 000- 0000 16h ADRESL A/D Result Register low byte xxxx xxxx uuuu uuuu 17h ADRESH A/D Result Register high byte xxxx xxxx uuuu uuuu Legend: x = unknown, u = unchanged,- = unimplemented read as '0',q - value depends on condition. Shaded cells are unimplemented, read as '0'. Note1: 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. 1998 Microchip Technology Inc. DS30289A-page 47 PIC17C7XX TABLE 7-3: SPECIAL FUNCTION REGISTERS (Cont.’d) Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR MCLR, WDT Bank 6: SSP Address register in I2C slave mode. SSP baud rate reload register in I2C master mode. 10h SSPADD 11h SSPCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 0000 0000 12h SSPCON2 GCEN AKSTAT AKDT AKEN RCEN PEN RSEN SEN 0000 0000 0000 0000 13h SSPSTAT SMP CKE D/A P S R/W UA BF 0000 0000 0000 0000 14h SSPBUF 15h Unimplemented — — — — — — — — ---- ---- ---- ---- 16h Unimplemented — — — — — — — — ---- ---- ---- ---- 17h Unimplemented — — — — — — — — ---- ---- ---- ---- Synchronous Serial Port Receive Buffer/Transmit Register 0000 0000 0000 0000 xxxx xxxx uuuu uuuu Bank 7: 10h PW3DCL DC1 DC0 TM2PW3 - - - - - xx0- ---- uu0- ---- 11h PW3DCH DC9 DC8 DC7 DC6 DC5 DC4 DC3 DC2 xxxx xxxx uuuu uuuu 12h CA3L Capture3 low byte xxxx xxxx uuuu uuuu 13h CA3H Capture3 high byte xxxx xxxx uuuu uuuu 14h CA4L Capture4 low byte xxxx xxxx uuuu uuuu 15h CA4H Capture4 high byte 16h TCON3 — CA4OVF CA3OVF CA4ED1 CA4ED0 CA3ED1 CA3ED0 17h Unimplemented — — — — — — — — ---- ---- ---- ---- RH4/ AN12 RH3 RH2 RH1 RH0 xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu PWM3ON -000 0000 -000 0000 Bank 8:(3) 10h(3) DDRH 11h(3) PORTH (4) 12h(3) DDRJ 13h(3) PORTJ (4) RJ7 RJ6 RJ5 RJ4 RJ3 RJ2 RJ1 RJ0 xxxx xxxx uuuu uuuu 14h(3) Unimplemented — — — — — — — — ---- ---- ---- ---- 15h(3) Unimplemented — — — — — — — — ---- ---- ---- ---- 16h(3) Unimplemented — — — — — — — — ---- ---- ---- ---- 17h(3) Unimplemented — — — — — — — — ---- ---- ---- ---- Data direction register for PORTH RH7/ AN15 RH6/ AN14 RH5/ AN13 1111 1111 1111 1111 Data direction register for PORTJ 1111 1111 1111 1111 Unbanked 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) xxxx xxxx uuuu uuuu Legend: x = unknown, u = unchanged,- = unimplemented read as '0',q - value depends on condition. Shaded cells are unimplemented, read as '0'. Note1: 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. DS30289A-page 48 1998 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). FIGURE 7-6: 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. Note 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. ALUSTA REGISTER (ADDRESS: 04h, UNBANKED) R/W - 1 R/W - 1 R/W - 1 R/W - 1 FS3 FS2 FS1 FS0 bit7 R/W - x OV R/W - x Z R/W - x DC R/W - x C bit0 R = Readable bit W = Writable bit -n = Value at POR reset (x = unknown) 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 bit 5-4: FS1:FS0: FSR0 Mode Select bits 00 = Post auto-decrement FSR0 value 01 = Post auto-increment FSR0 value 1x = FSR0 value does not change bit 3: 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 bit 2: Z: Zero bit 1 = The result of an arithmetic or logic operation is zero 0 = The results of an arithmetic or logic operation is not zero bit 1: 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: For borrow the polarity is reversed. bit 0: 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: For borrow the polarity is reversed. 1998 Microchip Technology Inc. DS30289A-page 49 PIC17C7XX 7.2.2.2 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. 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. FIGURE 7-7: U-0 — bit7 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). CPUSTA REGISTER (ADDRESS: 06h, UNBANKED) U-0 — R-1 R/W - 1 STKAV GLINTD R-1 TO R-1 PD R/W - 0 POR R/W - 1 BOR bit0 R = Readable bit W = Writable bit U = Unimplemented bit, Read as ‘0’ - n = Value at POR reset bit 7-6: Unimplemented: Read as '0' bit 5: 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) bit 4: 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 un-masked interrupts bit 3: TO: WDT Time-out Status bit 1 = After power-up or by a CLRWDT instruction 0 = A Watchdog Timer time-out occurred bit 2: PD: Power-down Status bit 1 = After power-up or by the CLRWDT instruction 0 = By execution of the SLEEP instruction bit 1: POR: Power-on Reset Status bit 1 = No Power-on Reset occurred 0 = A Power-on Reset occurred (must be set by software) bit 0: 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 DS30289A-page 50 1998 Microchip Technology Inc. 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. FIGURE 7-8: R/W - 0 INTEDG bit7 T0STA REGISTER (ADDRESS: 05h, UNBANKED) 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 — bit0 R = Readable bit W = Writable bit U = Unimplemented, reads as ‘0’ -n = Value at POR reset 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 bit 6: 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 bit 4-1: 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 Unimplemented: Read as '0' 1998 Microchip Technology Inc. DS30289A-page 51 PIC17C7XX 7.3 Stack Operation 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 “PUSHed” onto the stack when a CALL or LCALL instruction is executed or an interrupt is acknowledged. The stack is “POPed” 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. 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. Note 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. Note 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 “PUSHed” 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). DS30289A-page 52 1998 Microchip Technology Inc. PIC17C7XX 7.4 Indirect Addressing 7.4.2 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 7-9 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 7-9: INDIRECT ADDRESSING RAM Instruction Executed Opcode Opcode 8 File • 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). 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. File = INDFx 8 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: 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). Address 8 Instruction Fetched INDIRECT ADDRESSING OPERATION FSR A simple program to clear RAM from 20h - FFh is shown in Example 7-1. EXAMPLE 7-1: 7.4.1 INDIRECT ADDRESSING 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. LP MOVLW MOVWF BCF BSF BCF MOVLW CLRF CPFSEQ GOTO : : 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 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. 1998 Microchip Technology Inc. DS30289A-page 53 PIC17C7XX 7.5 Table Pointer (TBLPTRL and TBLPTRH) 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. DS30289A-page 54 1998 Microchip Technology Inc. PIC17C7XX 7.7 Program Counter Module Using Figure 7-10, the operations of the PC and PCLATH for different instructions are as follows: 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. a) b) c) d) Figure 7-10 and Figure 7-11 show the operation of the program counter for various situations. FIGURE 7-10: PROGRAM COUNTER OPERATION e) Internal data bus <8> Using Figure 7-11, the operation of the PC and PCLATH for GOTO and CALL instructions is as follows: 8 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> 8 PCLATH 8 PCH PCL FIGURE 7-11: PROGRAM COUNTER USING THE CALL AND GOTO INSTRUCTIONS 15 13 12 8 7 From Instruction 0 5 PC<15:13> 3 7 54 0 PCLATH 8 0 8 7 PCH 1998 Microchip Technology Inc. PCL 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: 8 15 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<MRU> → PC<15:0> 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). DS30289A-page 55 PIC17C7XX 7.8 Bank Select Register (BSR) 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. The BSR is used to switch between banks in the data memory area (Figure 7-12). 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. 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. 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. 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 7-12: BSR OPERATION BSR 7 4 3 (2) 0 (1) Address Range 0 1 2 3 4 5 6 7 8 10h 15 SFR (Peripheral) Banks ••• 17h Bank 0 Bank 1 Bank 2 Bank 3 Bank 4 Bank 5 Bank 6 Bank 7 Bank 8 0 1 2 3 15 4 20h Bank 15 GPR (RAM) Banks ••• FFh Bank 0 Bank 1 Bank 2 Bank 3 Bank 4 Bank 15 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. DS30289A-page 56 1998 Microchip Technology Inc. PIC17C7XX 8.0 TABLE READS AND TABLE WRITES FIGURE 8-2: 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. TABLE POINTER TBLPTRH TABLATH Data Memory 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. f FIGURE 8-1: TLWT INSTRUCTION OPERATION TBLPTRL TABLE LATCH (16-bit) 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. Figure 8-1 through Figure 8-4 show the operation of these four instructions. The steps show the sequence of operation. TABLWT INSTRUCTION OPERATION TABLATL 3 TABLWT 0,i,f 3 TABLWT 1,i,f Program Memory 1 Prog-Mem (TBLPTR) 2 TABLE POINTER TBLPTRH TBLPTRL TABLE LATCH (16-bit) TABLATH TABLATL TLWT 1,f Data Memory TLWT 0,f 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. Program Memory f 1 Step 1: 8-bit value, from register 'f', loaded into the high or low byte in TABLAT (16-bit). 1998 Microchip Technology Inc. DS30289A-page 57 PIC17C7XX FIGURE 8-3: TLRD INSTRUCTION OPERATION FIGURE 8-4: TABLE POINTER TABLE POINTER TBLPTRH TBLPTRH TBLPTRL TLRD 1,f TBLPTRL TABLE LATCH (16-bit) TABLE LATCH (16-bit) TABLATH TABLRD INSTRUCTION OPERATION TABLATH TABLATL TABLATL TLRD 0,f 3 TABLRD 0,i,f 3 TABLRD 1,i,f Data Memory Program Memory Data Memory Program Memory 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'. DS30289A-page 58 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. 1998 Microchip Technology Inc. PIC17C7XX 8.1 Table Writes to Internal Memory 8.1.1 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. Note 2: If the VPP requirement is not met, the table write is a 2 cycle write and the program memory is unchanged. TABLE 8-1: Interrupt Source TERMINATING LONG WRITES 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 (an NOP is executed). The highest priority pending interrupt, from the T0CKI, RA0/INT, or TMR0 sources that is enabled, has its flag cleared. Note 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. INTERRUPT - TABLE WRITE INTERACTION GLINTD Enable Bit Flag Bit RA0/INT, TMR0, T0CKI 0 1 1 0 1 1 1 0 1 0 x 1 Peripheral 0 0 1 1 1 1 0 1 1 0 x 1 1998 Microchip Technology Inc. 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 table write, do not branch to interrupt vector (flag remains set). DS30289A-page 59 PIC17C7XX 8.2 Table Writes to External Memory 8.2.2 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. 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. EXAMPLE 8-1: Note: If an interrupt is pending or occurs during the TABLWT, the two cycle table write completes. The RA0/INT, TMR0, or T0CKI interrupt flag is automatically cleared or the pending peripheral interrupt is acknowledged. FIGURE 8-5: CLRWDT MOVLW MOVWF MOVLW MOVWF MOVLW TLWT MOVLW TABLWT TABLE WRITE HIGH (TBL_ADDR) TBLPTRH LOW (TBL_ADDR) TBLPTRL HIGH (DATA) 1, WREG LOW (DATA) 0,0,WREG ; ; ; ; ; ; ; ; ; ; ; ; Clear WDT Load the Table address Load HI byte in TABLATH Load LO byte in TABLATL and write to program memory (Ext. SRAM) TABLWT WRITE TIMING (EXTERNAL MEMORY) Q1 Q2 Q3 Q4 AD15:AD0 PC Instruction fetched TABLWT Instruction executed INST (PC-1) Q1 Q2 Q3 Q4 PC+1 Q1 Q2 Q3 Q4 TBL Data out INST (PC+1) TABLWT cycle1 Q1 Q2 Q3 Q4 PC+2 INST (PC+2) TABLWT cycle2 INST (PC+1) Data write cycle 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. DS30289A-page 60 1998 Microchip Technology Inc. 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 PC Instruction fetched TABLWT1 Instruction executed INST (PC-1) PC+1 TBL1 Data out 1 TABLWT2 PC+2 TBL2 Data out 2 INST (PC+2) INST (PC+3) TABLWT1 cycle1 TABLWT1 cycle2 TABLWT2 cycle1 TABLWT2 cycle2 Data write cycle PC+3 INST (PC+2) Data write cycle ALE OE WR 1998 Microchip Technology Inc. DS30289A-page 61 PIC17C7XX 8.3 Table Reads EXAMPLE 8-2: 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. FIGURE 8-7: MOVLW MOVWF MOVLW MOVWF TABLRD TLRD TABLRD TABLE READ 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 TABLRD TIMING Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 AD15:AD0 PC Instruction fetched TABLRD Instruction executed INST (PC-1) PC+1 TBL Data in INST (PC+2) INST (PC+1) TABLRD cycle1 PC+2 TABLRD cycle2 INST (PC+1) Data read cycle ALE OE WR FIGURE 8-8: '1' 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 PC Instruction fetched TABLRD1 Instruction executed INST (PC-1) PC+1 TBL1 Data in 1 PC+2 TBL2 Data in 2 INST (PC+2) TABLRD2 INST (PC+3) TABLRD1 cycle1 TABLRD1 cycle2 TABLRD2 cycle1 TABLRD2 cycle2 Data read cycle PC+3 INST (PC+2) Data read cycle ALE OE '1' WR DS30289A-page 62 1998 Microchip Technology Inc. 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) 1998 Microchip Technology Inc. TABLWT DS30289A-page 63 PIC17C7XX NOTES: DS30289A-page 64 1998 Microchip Technology Inc. PIC17C7XX 9.0 HARDWARE MULTIPLIER 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. 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. EXAMPLE 9-1: MOVFP MULWF 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 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. TABLE 9-1: Routine 8 x 8 unsigned 8 x 8 signed 16 x 16 unsigned 16 x 16 signed ARG1, WREG ARG2 EXAMPLE 9-2: The performance increase allows the device to be used in applications previously reserved for Digital Signal Processors. 8 x 8 UNSIGNED MULTIPLY ROUTINE ; ; ARG1 * ARG2 -> ; PRODH:PRODL 8 x 8 SIGNED MULTIPLY ROUTINE MOVFP MULWF ARG1, WREG ARG2 BTFSC SUBWF ARG2, SB PRODH, F MOVFP BTFSC SUBWF ARG2, WREG ARG1, SB PRODH, F ; ARG1 * ARG2 -> ; PRODH:PRODL ; Test Sign Bit ; PRODH = PRODH ; - ARG1 ; Test Sign Bit ; PRODH = PRODH ; - ARG2 PERFORMANCE COMPARISON Multiply Method Without hardware multiply Hardware multiply Without hardware multiply Hardware multiply Without hardware multiply Hardware multiply Without hardware multiply Hardware multiply 1998 Microchip Technology Inc. Program Memory (Words) Cycles (Max) Time @ 33 MHz @ 16 MHz @ 8 MHz 13 1 — 6 21 24 52 36 69 1 — 6 242 24 254 36 8.364 µs 0.121 µs — 0.727 µs 29.333 µs 2.91 µs 30.788 µs 4.36 µs 17.25 µs 0.25 µs — 1.50 µs 60.50 µs 6.0 µs 63.50 µs 9.0 µs 34.50 µs 0.50 µs — 3.0 µs 121.0 µs 12.0 µs 127.0 µs 18.0 µs DS30289A-page 65 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. EQUATION 9-1: RES3:RES0 16 x 16 UNSIGNED MULTIPLICATION ALGORITHM EXAMPLE 9-3: MOVFP MULWF MOVPF MOVPF 16 x 16 UNSIGNED MULTIPLY ROUTINE ARG1L, WREG ARG2L ; ARG1L * ARG2L -> ; PRODH:PRODL PRODH, RES1 ; PRODL, RES0 ; ; = ARG1H:ARG1L • ARG2H:ARG2L = (ARG1H • ARG2H • 216) + (ARG1H • ARG2L • 28) + (ARG1L • ARG2H • 28) + MOVFP MULWF MOVPF MOVPF ARG1H, WREG ARG2H ; ARG1H * ARG2H -> ; PRODH:PRODL PRODH, RES3 ; PRODL, RES2 ; ; MOVFP MULWF (ARG1L • ARG2L) MOVFP ADDWF MOVFP ADDWFC CLRF ADDWFC ARG1L, WREG ARG2H ; ARG1L * ARG2H -> ; PRODH:PRODL PRODL, WREG ; RES1, F ; Add cross PRODH, WREG ; products RES2, F ; WREG, F ; RES3, F ; ; MOVFP MULWF MOVFP ADDWF MOVFP ADDWFC CLRF ADDWFC DS30289A-page 66 ARG1H, WREG ; ARG2L ; ARG1H * ARG2L -> ; PRODH:PRODL PRODL, WREG ; RES1, F ; Add cross PRODH, WREG ; products RES2, F ; WREG, F ; RES3, F ; 1998 Microchip Technology Inc. PIC17C7XX Example 9-4 shows the sequence to do an 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. EQUATION 9-2: 16 x 16 SIGNED MULTIPLICATION ALGORITHM EXAMPLE 9-4: MOVFP MULWF MOVPF MOVPF 16 x 16 SIGNED MULTIPLY ROUTINE ARG1L, WREG ARG2L ; ARG1L * ARG2L -> ; PRODH:PRODL PRODH, RES1 ; PRODL, RES0 ; ; MOVFP MULWF RES3:RES0 MOVPF MOVPF = ARG1H:ARG1L • ARG2H:ARG2L ARG1H, WREG ARG2H ; ARG1H * ARG2H -> ; PRODH:PRODL PRODH, RES3 ; PRODL, RES2 ; ; = (ARG1H • ARG2H • 216) + (ARG1H • ARG2L • 28) + (ARG1L • ARG2H • 28) + (ARG1L • ARG2L) + (-1 • ARG2H<7> • ARG1H:ARG1L • 216) + MOVFP MULWF MOVFP ADDWF MOVFP ADDWFC CLRF ADDWFC (-1 • ARG1H<7> • ARG2H:ARG2L • 216) ARG1L, WREG ARG2H ; ARG1L * ARG2H -> ; PRODH:PRODL PRODL, WREG ; RES1, F ; Add cross PRODH, WREG ; products RES2, F ; WREG, F ; RES3, F ; ; MOVFP MULWF MOVFP ADDWF MOVFP ADDWFC CLRF ADDWFC ARG1H, WREG ; ARG2L ; ARG1H * ARG2L -> ; PRODH:PRODL PRODL, WREG ; RES1, F ; Add cross PRODH, WREG ; products RES2, F ; WREG, F ; RES3, F ; BTFSS GOTO MOVFP SUBWF MOVFP SUBWFB ARG2H, 7 SIGN_ARG1 ARG1L, WREG RES2 ARG1H, WREG RES3 ; ARG2H:ARG2L neg? ; no, check ARG1 ; ; ; ARG1H, 7 CONT_CODE ARG2L, WREG RES2 ARG2H, WREG RES3 ; ARG1H:ARG1L neg? ; no, done ; ; ; ; ; SIGN_ARG1 BTFSS GOTO MOVFP SUBWF MOVFP SUBWFB ; CONT_CODE : 1998 Microchip Technology Inc. DS30289A-page 67 PIC17C7XX NOTES: DS30289A-page 68 1998 Microchip Technology Inc. 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 1998 Microchip Technology Inc. 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<y> 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-impendance inputs. The reset state of some peripheral modules may force the I/O to other operations, such as analog inputs or the system bus. DS30289A-page 69 PIC17C7XX 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 high impedance 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 force to be high impedance inputs. FIGURE 10-1: RA0 AND RA1 BLOCK DIAGRAM DATA BUS 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 are automatically configured by their multiplexed peripheral module. 10.1.1 RD_PORTA (Q2) Note: Input pins have protection diodes to VDD and VSS. FIGURE 10-2: RA2 BLOCK DIAGRAM Peripheral data in USING RA2, RA3 AS OUTPUTS D 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 Q EN RD_PORTA (Q2) Q 1 0 Q D CK WR_PORTA (Q4) SCL out I2C Mode enable Note: I/O pin has protection diodes to VSS. 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: INITIALIZING PORTA MOVLB MOVLW MOVWF 0 0xF3 PORTA DS30289A-page 70 ; Select Bank 0 ; ; Initialize PORTA ; RA<3:2> are output low ; RA<5:4> and RA<1:0> ; are inputs ; (outputs floating) 1998 Microchip Technology Inc. PIC17C7XX FIGURE 10-3: RA3 BLOCK DIAGRAM FIGURE 10-4: RA4 AND RA5 BLOCK DIAGRAM Peripheral data in Serial port input signal D Data Bus Q EN Data Bus RD_PORTA (Q2) RD_PORTA (Q2) Q D Q Serial port output signals WR_PORTA (Q4) SDA out CK 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: PORTA FUNCTIONS Bit0 Buffer Type RA0/INT RA1/T0CKI Name bit0 bit1 ST ST RA2/SS/SCL bit2 ST RA3/SDI/SDA bit3 ST RA4/RX1/DT1 bit4 ST RA5/TX1/CK1 bit5 ST RBPU bit7 — Legend: ST = Schmitt Trigger input. TABLE 10-2: Function 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 or USART1 Synchronous Data. Input or USART1 Asynchronous Transmit or USART1 Synchronous Clock. Control bit for PORTB weak pull-ups. REGISTERS/BITS ASSOCIATED WITH PORTA Value on POR, BOR MCLR, WDT RA0/INT 0-xx 11xx 0-uu 11uu 0000 000- Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 10h, Bank 0 PORTA (1) RBPU — RA5/ TX1/CK1 RA4/ RX1/DT1 RA3/ SDI/SDA RA2/ SS/SCL RA1/T0CKI 05h, Unbanked T0STA INTEDG T0SE T0CS T0PS3 T0PS2 T0PS1 T0PS0 — 0000 000- 13h, Bank 0 RCSTA1 SPEN RX9 SREN CREN — FERR OERR RX9D 0000 -00x 0000 -00u 15h, Bank 0 TXSTA1 CSRC TX9 TXEN SYNC — — TRMT TX9D 0000 --1x 0000 --1u Legend: Note 1: x = unknown, u = unchanged, - = unimplemented reads as '0'. Shaded cells are not used by PORTA. On any device reset, these pins are configured as inputs. 1998 Microchip Technology Inc. DS30289A-page 71 PIC17C7XX 10.2 PORTB and DDRB Registers This interrupt can wake the device from SLEEP. The user, in the interrupt service routine, can clear the interrupt by: 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. a) b) Read-Write PORTB (such as; MOVPF PORTB, PORTB). This will end 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. 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. This interrupt on mismatch feature, together with software configurable pull-ups on this port, allows easy interface to a keypad and make it possible for wake-up on key-depression. For an example, refer to Application Note AN552, “Implementing Wake-up on Keystroke.” 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’ed together to set the PORTB Interrupt Flag bit, RBIF (PIR1<7>). 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 RBIF Port Input Latch Data Bus RD_DDRB (Q2) RD_PORTB (Q2) D OE Q WR_DDRB (Q4) CK D Port Data Q CK WR_PORTB (Q4) Note: I/O pins have protection diodes to VDD and VSS. DS30289A-page 72 1998 Microchip Technology Inc. PIC17C7XX EXAMPLE 10-2: INITIALIZING PORTB 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. MOVLB CLRF MOVLW MOVWF 0 ; Select Bank 0 PORTB, F ; Init PORTB by clearing ; output data latches 0xCF ; Value used to initialize ; data direction DDRB ; 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 WR_DDRB (Q4) CK D Port Data Q CK R WR_PORTB (Q4) Peripheral_output Peripheral_enable Note: I/O pins have protection diodes to VDD and Vss. 1998 Microchip Technology Inc. DS30289A-page 73 PIC17C7XX 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 Q Data Bus EN RD_DDRB (Q2) RD_PORTB (Q2) D OE Q WR_DDRB (Q4) CK P 0 Port Data 1 Q N Q D WR_PORTB (Q4) CK SPI output SPI output enable 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 Q Data Bus EN RD_DDRB (Q2) RD_PORTB (Q2) D Q OE WR_DDRB (Q4) CK P 0 Port Data 1 Q N Q SS output disable D CK WR_PORTB (Q4) SPI output SPI output enable Note: I/O pin has protection diodes to VDD and Vss. DS30289A-page 74 1998 Microchip Technology Inc. PIC17C7XX TABLE 10-3: PORTB FUNCTIONS Bit Buffer Type Function RB0/CAP1 Name bit0 ST RB1/CAP2 bit1 ST RB2/PWM1 bit2 ST RB3/PWM2 bit3 ST RB4/TCLK12 bit4 ST RB5/TCLK3 bit5 ST RB6/SCK bit6 ST RB7/SDO bit7 ST 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: REGISTERS/BITS ASSOCIATED WITH PORTB Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 12h, Bank 0 PORTB RB7/ SDO RB6/ SCK RB5/ TCLK3 RB4/ TCLK12 RB3/ PWM2 RB2/ PWM1 RB1/ CAP2 RB0/ CAP1 11h, Bank 0 DDRB — RA5/ TX1/CK1 RA4/ RX1/DT1 RA3/ SDI/SDA RA2/ SS/SCL RA1/T0CKI Data direction register for PORTB MCLR, WDT xxxx xxxx uuuu uuuu 1111 1111 1111 1111 RA0/INT 0-xx 11xx 0-uu 11uu POR BOR --11 11qq --11 qquu T0IE INTE 0000 0000 0000 0000 CA1IF TX1IF RC1IF x000 0010 u000 0010 CA2IE CA1IE TX1IE RC1IE 0000 0000 0000 0000 T16 TMR3CS TMR2CS TMR1CS 0000 0000 0000 0000 CA2OVF CA1OVF PWM2ON PWM1ON CA1/PR3 TMR3ON TMR2ON TMR1ON 0000 0000 0000 0000 10h, Bank 0 PORTA 06h, Unbanked CPUSTA — — STKAV GLINTD TO PD 07h, Unbanked INTSTA PEIF T0CKIF T0IF INTF PEIE T0CKIE 16h, Bank 1 PIR1 RBIF TMR3IF TMR2IF TMR1IF CA2IF 17h, Bank 1 PIE1 RBIE TMR3IE TMR2IE TMR1IE 16h, Bank 3 TCON1 CA2ED1 CA2ED0 CA1ED1 CA1ED0 17h, Bank 3 TCON2 Legend: Value on POR, BOR RBPU x = unknown, u = unchanged, - = unimplemented read as '0', q = Value depends on condition. Shaded cells are not used by PORTB. 1998 Microchip Technology Inc. DS30289A-page 75 PIC17C7XX 10.3 PORTC and DDRC Registers 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. 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: EXAMPLE 10-3: INITIALIZING PORTC MOVLB CLRF 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. 1 PORTC, F MOVLW 0xCF MOVWF DDRC ; ; ; ; ; ; ; ; ; 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 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 D Q WR_PORTC CK D Q R CK S RD_DDRC WR_DDRC EX_EN DATA/ADDR_OUT DRV_SYS SYS BUS Control Note: I/O pins have protection diodes to VDD and Vss. DS30289A-page 76 1998 Microchip Technology Inc. PIC17C7XX TABLE 10-5: PORTC FUNCTIONS Name Bit Buffer Type Function RC0/AD0 bit0 TTL Input/Output or system bus address/data pin. RC1/AD1 bit1 TTL Input/Output or system bus address/data pin. RC2/AD2 bit2 TTL Input/Output or system bus address/data pin. RC3/AD3 bit3 TTL Input/Output or system bus address/data pin. RC4/AD4 bit4 TTL Input/Output or system bus address/data pin. RC5/AD5 bit5 TTL Input/Output or system bus address/data pin. RC6/AD6 bit6 TTL Input/Output or system bus address/data pin. RC7/AD7 bit7 TTL Input/Output or system bus address/data pin. Legend: TTL = TTL input. TABLE 10-6: REGISTERS/BITS ASSOCIATED WITH PORTC Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 11h, Bank 1 PORTC RC7/ AD7 RC6/ AD6 RC5/ AD5 RC4/ AD4 RC3/ AD3 RC2/ AD2 RC1/ AD1 RC0/ AD0 10h, Bank 1 DDRC Data direction register for PORTC Value on POR, BOR MCLR, WDT xxxx xxxx uuuu uuuu 1111 1111 1111 1111 Legend: x = unknown, u = unchanged. 1998 Microchip Technology Inc. DS30289A-page 77 PIC17C7XX 10.4 PORTD and DDRD Registers 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. 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: EXAMPLE 10-4: INITIALIZING PORTD MOVLB CLRF 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. 1 PORTD, F MOVLW 0xCF MOVWF DDRD ; ; ; ; ; ; ; ; ; 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 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 D Q WR_PORTD CK D Q R CK S RD_DDRD WR_DDRD EX_EN DATA/ADDR_OUT DRV_SYS SYS BUS Control Note: I/O pins have protection diodes to VDD and Vss. DS30289A-page 78 1998 Microchip Technology Inc. PIC17C7XX TABLE 10-7: Name PORTD FUNCTIONS Bit Buffer Type RD0/AD8 bit0 RD1/AD9 bit1 RD2/AD10 bit2 RD3/AD11 bit3 RD4/AD12 bit4 RD5/AD13 bit5 RD6/AD14 bit6 RD7/AD15 bit7 Legend: TTL = TTL input. TABLE 10-8: Address 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. REGISTERS/BITS ASSOCIATED WITH PORTD Name 13h, Bank 1 PORTD 12h, Bank 1 DDRD Bit 7 Bit 6 RD7/ AD15 RD6/ AD14 Bit 5 RD5/ AD13 Bit 4 RD4/ AD12 Data direction register for PORTD Bit 3 RD3/ AD11 Bit 2 RD2/ AD10 Bit 1 RD1/ AD9 Bit 0 RD0/ AD8 Value on POR, BOR MCLR, WDT xxxx xxxx uuuu uuuu 1111 1111 1111 1111 Legend: x = unknown, u = unchanged. 1998 Microchip Technology Inc. DS30289A-page 79 PIC17C7XX 10.5 PORTE and DDRE Register 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. 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: EXAMPLE 10-5: INITIALIZING PORTE MOVLB CLRF 1 PORTE, F MOVLW 0x03 MOVWF DDRE 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. ; ; ; ; ; ; ; ; ; ; ; 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' FIGURE 10-11: BLOCK DIAGRAM OF RE2:RE0 (IN I/O PORT MODE) Data Bus TTL Input Buffer RD_PORTE Port 0 Data 1 D Q WR_PORTE CK D Q R CK S RD_DDRE WR_DDRE EX_EN CNTL DRV_SYS SYS BUS Control Note: I/O pins have protection diodes to VDD and Vss. DS30289A-page 80 1998 Microchip Technology Inc. PIC17C7XX FIGURE 10-12: BLOCK DIAGRAM OF RE3/CAP4 PORT PIN Peripheral In D Data Bus Q EN EN VDD RD_PORTE P Q Port Data Q N D RD_DDRE D Q Q WR_PORTE CK WR_DDRE CK S Note: I/O pin has protection diodes to VDD and Vss. TABLE 10-9: PORTE FUNCTIONS Name Bit Buffer Type bit0 RE0/ALE RE1/OE bit1 RE2/WR bit2 RE3/CAP4 bit3 Legend: TTL = TTL input. Function TTL Input/Output or system bus Address Latch Enable (ALE) control pin. TTL Input/Output or system bus Output Enable (OE) control pin. TTL Input/Output or system bus Write (WR) control pin. ST Input/Output or Capture4 input pin ST = Schmitt Trigger input TABLE 10-10: REGISTERS/BITS ASSOCIATED WITH PORTE Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR MCLR, WDT — — — — RE3/CAP4 RE2/WR RE1/OE RE0/ALE ---- xxxx ---- uuuu ---- 1111 ---- 1111 Capture4 low byte xxxx xxxx uuuu uuuu Capture4 high byte xxxx xxxx uuuu uuuu -000 0000 -000 0000 Address Name 15h, Bank 1 PORTE 14h, Bank 1 DDRE Data direction register for PORTE 14h, Bank 7 CA4L 15h, Bank 7 CA4H 16h, Bank 7 TCON3 Legend: — CA4OVF CA3OVF CA4ED1 CA4ED0 CA3ED1 CA3ED0 PWM3ON x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by PORTE. 1998 Microchip Technology Inc. DS30289A-page 81 PIC17C7XX 10.6 PORTF and DDRF Registers 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. 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. EXAMPLE 10-6: INITIALIZING PORTF All eight bits of PORTF are multiplexed with 8 channels of the 10-bit A/D converter. MOVLB MOVLW MOVPF CLRF 5 0x0E ADCON1 PORTF, F Upon reset the entire Port is automatically configured as analog inputs, and must be configured in software to be a digital I/O. MOVLW 0x03 MOVWF DDRF ; ; ; ; ; ; ; ; ; ; ; 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: BLOCK DIAGRAM OF RF7:RF0 Data bus D Q VDD WR PORTF Q CK P Data Latch I/O pin D Q CK Q N WR DDRF VSS DDRF Latch ST input buffer RD DDRF Q D EN EN RD PORTF PCFG3:PCFG0 To other pads VAIN CHS3:CHS0 To other pads Note: I/O pins have protection diodes to VDD and VSS. DS30289A-page 82 1998 Microchip Technology Inc. PIC17C7XX TABLE 10-11: PORTF FUNCTIONS Name Bit Buffer Type RF0/AN4 ST Input/Output or analog input 4 RF1/AN5 bit0 bit1 Function ST Input/Output or analog input 5 RF2/AN6 bit2 ST Input/Output or analog input 6 RF3/AN7 bit3 ST Input/Output or analog input 7 RF4/AN8 bit4 ST Input/Output or analog input 8 RF5/AN9 bit5 ST Input/Output or analog input 9 RF6/AN10 bit6 ST Input/Output or analog input 10 RF7/AN11 bit7 ST Input/Output or analog input 11 Legend: ST = Schmitt Trigger input. TABLE 10-12: REGISTERS/BITS ASSOCIATED WITH PORTF Address Name Bit 7 Bit 6 10h, Bank 5 DDRF 11h, Bank 5 PORTF 15h, Bank 5 ADCON1 ADCS1 ADCS0 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Data Direction Register for PORTF RF7/ AN11 RF6/ AN10 Value on POR, BOR MCLR, WDT 1111 1111 1111 1111 RF5/ AN9 RF4/ AN8 RF3/ AN7 RF2/ AN6 RF1/ AN5 ADFM — PCFG3 PCFG2 PCFG1 RF0/ AN4 0000 0000 0000 0000 PCFG0 000- 0000 000- 0000 Legend: x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by PORTF. 1998 Microchip Technology Inc. DS30289A-page 83 PIC17C7XX 10.7 PORTG and DDRG Registers 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. 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. EXAMPLE 10-7: INITIALIZING PORTG MOVLB MOVLW MOVPF CLRF 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. 5 0x0E ADCON1 PORTG, F MOVLW 0x03 MOVWF DDRG Upon reset RG3:RG0 is automatically configured as analog inputs, and must be configured in software to be a digital I/O. ; ; ; ; ; ; ; ; ; ; ; Select Bank 5 Configure PORTG as digital Initialize PORTG data latches before the data direction register Value used to init data direction Set RG<1:0> as inputs RG<7:2> as outputs FIGURE 10-14: BLOCK DIAGRAM OF RG3:RG0 Data bus D Q CK Q VDD WR PORTG P Data Latch I/O pin D Q CK Q N WR DDRG VSS DDRG Latch ST input buffer RD DDRG Q D EN EN RD PORTG PCFG3:PCFG0 To other pads VAIN CHS3:CHS0 To other pads Note: I/O pins have protection diodes to VDD and VSS. DS30289A-page 84 1998 Microchip Technology Inc. PIC17C7XX FIGURE 10-15: RG4 BLOCK DIAGRAM Peripheral Data In Data Bus Q D EN EN RD_PORTG D VDD Q P D Q N Q WR_PORTG CK RD_DDRG WR_DDRG CK Note: I/O pin has protection diodes to VDD and Vss. FIGURE 10-16: RG7:RG5 BLOCK DIAGRAM Peripheral Data In D Data Bus Q NEN RD_PORTG VDD 1 P Port Data D Q Q WR_PORTG CK 0 D Q N Q CK R RD_DDRG WR_DDRG OUTPUT OUTPUT ENABLE Note: I/O pins have protection diodes to VDD and Vss. 1998 Microchip Technology Inc. DS30289A-page 85 PIC17C7XX TABLE 10-13: PORTG FUNCTIONS Name Bit Buffer Type RG0/AN3 ST Input/Output or analog input 3. RG1/AN2 bit0 bit1 Function ST Input/Output or analog input 2. RG2/AN1/VREF- bit2 ST Input/Output or analog input 1 or the ground reference voltage RG3/AN0/VREF+ bit3 ST Input/Output or analog input 0 or the positive reference voltage RG4/CAP3 bit4 ST Input/Output or the Capture3 input pin. RG5/PWM3 bit5 ST Input/Output or the PWM3 output pin. RG6/RX2/DT2 bit6 ST Input/Output or the USART2 (SCI) Asynchronous Receive or USART2 (SCI) Synchronous Data. RG7/TX2/CK2 bit7 ST Input/Output or the USART2 (SCI) Asynchronous Transmit or USART2 (SCI) Synchronous Clock. Legend: ST = Schmitt Trigger input. TABLE 10-14: REGISTERS/BITS ASSOCIATED WITH PORTG Address Name Bit 7 12h, Bank 5 DDRG Data Direction Register for PORTG 13h, Bank 5 PORTG RG7/ RG6/ TX2/CK2 RX2/DT2 15h, Bank 5 ADCON1 ADCS1 Bit 6 ADCS0 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR MCLR, WDT 1111 1111 1111 1111 RG5/ PWM3 RG4/ CAP3 RG3/ AN0 RG2/ AN1 RG1/ AN2 RG0/ AN3 xxxx 0000 uuuu 0000 ADFM — PCFG3 PCFG2 PCFG1 PCFG0 000- 0000 000- 0000 Legend: x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by PORTG. DS30289A-page 86 1998 Microchip Technology Inc. PIC17C7XX 10.8 PORTH and DDRH Registers (PIC17C76X only) EXAMPLE 10-8: INITIALIZING PORTH MOVLB MOVLW MOVPF CLRF 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. 8 0x0E ADCON1 PORTH, F MOVLW 0x03 MOVWF DDRH ; ; ; ; ; ; ; ; ; ; ; 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 The remaining bits of PORTH are general purpose I/O. Upon reset RH7:RH4 is automatically configured as analog inputs, and must be configured in software to be a digital I/O. Figure 10-17: Block Diagram of RH7:RH4 Data bus D Q VDD WR PORTH Q CK P Data Latch I/O pin D Q CK Q N WR DDRH VSS DDRH Latch ST input buffer RD DDRH Q D EN EN RD PORT PCFG3:PCFG0 To other pads VAIN CHS3:CHS0 To other pads Note: I/O pins have protection diodes to VDD and VSS. 1998 Microchip Technology Inc. DS30289A-page 87 PIC17C7XX Figure 10-18:RH3:RH0 Block Diagram Data Bus Q D EN EN RD_PORTH D VDD Q P Q RD_DDRH D Q N WR_PORTH CK WR_DDRH CK Note: I/O pins have protection diodes to VDD and Vss. TABLE 10-1: PORTH FUNCTIONS Name Bit Buffer Type RH0 ST Input/Output RH1 bit0 bit1 Function ST Input/Output RH2 bit2 ST Input/Output RH3 bit3 ST Input/Output RH4/AN12 bit4 ST Input/Output or analog input 12 RH5/AN13 bit5 ST Input/Output or analog input 13 RH6/AN14 bit6 ST Input/Output or analog input 14 RH7/AN15 bit7 ST Input/Output or analog input 15 Legend: ST = Schmitt Trigger input. TABLE 10-2: Address REGISTERS/BITS ASSOCIATED WITH PORTH Name 10h, Bank 8 DDRH 11h, Bank 8 PORTH 15h, Bank 5 ADCON1 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Data Direction Register for PORTH RH7/ AN15 RH6/ AN14 ADCS1 ADCS0 Value on POR, BOR MCLR, WDT 1111 1111 1111 1111 RH5/ AN13 RH4/ AN12 RH3 RH2 RH1 ADFM — PCFG3 PCFG2 PCFG1 RH0 0000 xxxx 0000 uuuu PCFG0 000- 0000 000- 0000 Legend: x = unknown, u = unchanged. DS30289A-page 88 1998 Microchip Technology Inc. PIC17C7XX 10.9 PORTJ and DDRJ Registers (PIC17C76X only) EXAMPLE 10-1: INITIALIZING PORTJ MOVLB CLRF 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. 8 PORTJ, F MOVLW 0xCF MOVWF DDRJ ; ; ; ; ; ; ; ; ; ; 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 Figure 10-19:PORTJ Block Diagram D Data Bus Q EN EN RD_PORTJ D VDD P Q D Q N Q WR_PORTJ CK CK RD_DDRJ WR_DDRJ Note: I/O pins have protection diodes to VDD and Vss. 1998 Microchip Technology Inc. DS30289A-page 89 PIC17C7XX TABLE 10-1: PORTJ FUNCTIONS Name Bit Buffer Type RJ0 ST Input/Output RJ1 bit0 bit1 Function ST Input/Output RJ2 bit2 ST Input/Output RJ3 bit3 ST Input/Output RJ4 bit4 ST Input/Output RJ5 bit5 ST Input/Output RJ6 bit6 ST Input/Output RJ7 bit7 ST Input/Output Legend: ST = Schmitt Trigger input. TABLE 10-2: REGISTERS/BITS ASSOCIATED WITH PORTJ Address Name 12h, Bank 8 DDRJ 13h, Bank 8 PORTJ Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 RJ2 RJ1 RJ0 Data Direction Register for PORTJ RJ7 RJ6 RJ5 RJ4 RJ3 Value on, POR, BOR MCLR, WDT 1111 1111 1111 1111 xxxx xxxx uuuu uuuu Legend: x = unknown, u = unchanged. DS30289A-page 90 1998 Microchip Technology Inc. PIC17C7XX 10.10 I/O Programming Considerations 10.10.1 BI-DIRECTIONAL I/O PORTS 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 re-written 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 10-1: 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. Example 10-1 shows the possible effect of two sequential read-modify-write instructions on an I/O port. 1998 Microchip Technology Inc. DS30289A-page 91 PIC17C7XX 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. 10.10.2 SUCCESSIVE OPERATIONS ON I/O PORTS 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. The best way to address this is to add an 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. FIGURE 10-20: SUCCESSIVE I/O OPERATION Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 PC Instruction fetched PC + 1 MOVWF PORTB MOVF PORTB,W write to PORTB PC + 2 PC + 3 This example shows a write to PORTB followed by a read from PORTB. NOP NOP Note that: data setup time = (0.25TCY - TPD) RB7:RB0 where TCY = instruction cycle TPD = propagation delay Port pin sampled here Instruction executed Note: MOVWF PORTB write to PORTB MOVF PORTB,W Therefore, at higher clock frequencies, a write followed by a read may be problematic. NOP FIGURE 10-21: I/O CONNECTION ISSUES BSF PORTx, PINy PIC17CXXX Q2 I/O Q3 Q4 BSF PORTx, PINz Q1 Q2 Q3 Q4 Q1 VIL C(1) PORTx, PINy Read PORTx, PINy as low Note 1: This is not a capacitor to ground, but the effective capacitive loading on the trace. DS30289A-page 92 BSF PORTx, PINz clears the value to be driven on the PORTx, PINy pin. 1998 Microchip Technology Inc. PIC17C7XX 11.0 OVERVIEW OF TIMER RESOURCES 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. 11.1 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. 11.2 11.3 Timer2 Overview The Timer2 module is an 8-bit timer/counter with an 8-bit 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. 11.4 Timer3 Overview The Timer3 module is a 16-bit timer/counter with a 16-bit 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 mode, 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. Timer1 Overview The Timer1 module is an 8-bit timer/counter with an 8-bit 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. 1998 Microchip Technology Inc. DS30289A-page 93 PIC17C7XX NOTES: DS30289A-page 94 1998 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). FIGURE 12-1: T0STA REGISTER (ADDRESS: 05h, UNBANKED) R/W - 0 INTEDG bit7 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 — bit0 R = Readable bit W = Writable bit U = Unimplemented, Read as '0' -n = Value at POR reset 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 bit 6: 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 bit 4-1: 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 Unimplemented: Read as '0' 1998 Microchip Technology Inc. DS30289A-page 95 PIC17C7XX 12.1 Timer0 Operation 12.2 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. Using Timer0 with External Clock When an external clock input is used for Timer0, it is synchronized with the internal phase clocks. Figure 12-3 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 12-3 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 12-2: TIMER0 MODULE BLOCK DIAGRAM Interrupt on overflow sets T0IF (INTSTA<5>) 0 RA1/T0CKI Fosc/4 1 Prescaler (8 stage async ripple counter) T0SE (T0STA<6>) Synchronization TMR0H<8> TMR0L<8> PSOUT 4 T0CS (T0STA<5>) T0PS3:T0PS0 (T0STA<4:1>) Q2 Q4 FIGURE 12-3: 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) (note 3) Sampled (note 2) Prescaler output (note 1) Increment TMR0 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. DS30289A-page 96 1998 Microchip Technology Inc. PIC17C7XX 12.3 Read/Write Consideration for TMR0 12.3.2 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 12-2: 16-BIT WRITE Example 12-1 shows a 16-bit read. To ensure a proper read, interrupts must be disabled during this routine. BSF MOVFP MOVFP BCF EXAMPLE 12-1: 16-BIT READ MOVPF MOVPF MOVFP CPFSLT RETURN MOVPF MOVPF RETURN TMR0L, TMPLO TMR0H, TMPHI TMPLO, WREG TMR0L TMR0L, TMPLO TMR0H, TMPHI WRITING A 16-BIT VALUE TO TMR0 ;read low tmr0 ;read high tmr0 ;tmplo −> wreg ;tmr0l < wreg? ;no then return ;read low tmr0 ;read high tmr0 ;return 12.4 CPUSTA, GLINTD RAM_L, TMR0L RAM_H, TMR0H CPUSTA, GLINTD ; Disable interrupts ; ; ; Done, enable ; interrupts 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 12-4: TMR0 TIMING: WRITE HIGH OR LOW BYTE Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 AD15:AD0 PC PC+1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 PC+2 PC+3 PC+4 ALE TMR0L T0 T0+1 New T0 (NT0) New T0+1 Fetch Instruction executed 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) TMR0H 1998 Microchip Technology Inc. DS30289A-page 97 PIC17C7XX FIGURE 12-5: 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 TMR0L Instruction fetched Instruction executed 12 12 TMR0H FE 56 FF MOVFP MOVFP DATAL,TMR0L DATAH,TMR0H Write TMR0L Write TMR0H Previously Fetched Instruction AB 13 57 MOVPF TMR0L,W Read TMR0L MOVFP MOVFP DATAL,TMR0L DATAH,TMR0H Write TMR0L Write TMR0H MOVPF TMR0L,W Read TMR0L 58 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 In this example, old TMR0 value is 12FEh, new value of AB56h is written. TABLE 12-1: REGISTERS/BITS ASSOCIATED WITH TIMER0 Address Name Bit 7 Bit 6 05h, Unbanked T0STA INTEDG T0SE 06h, Unbanked CPUSTA — — 07h, Unbanked INTSTA PEIF T0CKIF T0IF 0Bh, Unbanked TMR0L TMR0 register; low byte 0Ch, Unbanked TMR0H TMR0 register; high byte Legend: Bit 5 Bit 0 Value on POR, BOR Bit 4 Bit 3 Bit 2 Bit 1 MCLR, WDT T0CS T0PS3 T0PS2 T0PS1 T0PS0 — 0000 000- 0000 000- STKAV GLINTD TO PD POR BOR --11 11qq --11 qquu INTF PEIE T0CKIE T0IE INTE 0000 0000 0000 0000 xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu x = unknown, u = unchanged, - = unimplemented read as a '0', q - value depends on condition, Shaded cells are not used by Timer0. DS30289A-page 98 1998 Microchip Technology Inc. PIC17C7XX 13.0 TIMER1, TIMER2, TIMER3, PWMS AND CAPTURES 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. 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. TABLE 13-1: TIME-BASE FUNCTION / RESOURCE REQUIREMENTS Time-base Function PWM1 PWM2 PWM3 Capture1 Capture2 Capture3 Capture4 Timer Resource Timer1 Timer1 or Timer2 Timer1 or Timer2 Timer3 Timer3 Timer3 Timer3 FIGURE 13-1: TCON1 REGISTER (ADDRESS: 16h, BANK 3) R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 CA2ED1 CA2ED0 CA1ED1 CA1ED0 T16 TMR3CS TMR2CS TMR1CS bit7 bit0 R = Readable bit W = Writable bit -n = Value at POR reset 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 bit 5-4: 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 bit 3: T16: Timer2:Timer1 Mode Select bit 1 = Timer2 and Timer1 form a 16-bit timer 0 = Timer2 and Timer1 are two 8-bit timers bit 2: 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 bit 1: 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 bit 0: 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 1998 Microchip Technology Inc. DS30289A-page 99 PIC17C7XX FIGURE 13-2: TCON2 REGISTER (ADDRESS: 17h, BANK 3) R-0 R-0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 CA2OVF CA1OVF PWM2ON PWM1ON CA1/PR3 TMR3ON TMR2ON TMR1ON bit7 bit0 R = Readable bit W = Writable bit -n = Value at POR reset bit 7: 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 bit 6: 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 bit 5: 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) bit 4: 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) bit 3: 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) bit 2: TMR3ON: Timer3 On bit 1 = Starts Timer3 0 = Stops Timer3 bit 1: 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 bit 0: 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 DS30289A-page 100 1998 Microchip Technology Inc. PIC17C7XX FIGURE 13-3: TCON3 REGISTER (ADDRESS: 16h, BANK 7) U-0 — bit7 R-0 R-0 CA4OVF CA3OVF R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 CA4ED1 CA4ED0 CA3ED1 CA3ED0 PWM3ON bit0 bit 7: Unimplemented: Read as ‘0’ bit 6: 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 bit 5: 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 R = Readable bit W = Writable bit U = Unimplemented bit, Reads as ‘0’ -n = Value at POR reset bit 4-3: 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 bit 2-1: 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 bit 0: 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) 1998 Microchip Technology Inc. DS30289A-page 101 PIC17C7XX 13.1 Timer1 and Timer2 13.1.1 TIMER1, TIMER2 IN 8-BIT MODE 13.1.1.1 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. 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. 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. FIGURE 13-4: TIMER1 AND TIMER2 IN TWO 8-BIT TIMER/COUNTER MODE Fosc/4 0 TMR1 Reset Set TMR1IF (PIR1<4>) 1 TMR1ON (TCON2<0>) TMR1CS (TCON1<0>) Comparator<8> Comparator x8 Equal PR1 RB4/TCLK12 1 TMR2 Fosc/4 TMR2ON (TCON2<1>) TMR2CS (TCON1<1>) DS30289A-page 102 Reset Set TMR2IF (PIR1<5>) 0 Comparator<8> Comparator x8 Equal PR2 1998 Microchip Technology Inc. PIC17C7XX 13.1.2 TIMER1 AND TIMER2 IN 16-BIT MODE 13.1.2.1 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 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. 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: EXTERNAL CLOCK INPUT FOR TMR2:TMR1 TURNING ON 16-BIT TIMER T16 TMR2ON TMR1ON Result 1 1 1 16-bit timer (TMR2:TMR1) ON 1 0 1 Only TMR1 increments 1 x 0 16-bit timer OFF 0 1 1 Timers in 8-bit mode FIGURE 13-5: TMR2 AND TMR1 IN 16-BIT TIMER/COUNTER MODE 1 RB4/TCLK12 Fosc/4 0 TMR1ON (TCON2<0>) TMR1CS (TCON1<0>) Set Interrupt TMR1IF (PIR1<4>) 1998 Microchip Technology Inc. MSB Reset Equal TMR2 x 8 LSB TMR1 x 8 Comparator<8> Comparator x16 PR2 x 8 PR1 x 8 DS30289A-page 103 PIC17C7XX TABLE 13-3: Address SUMMARY OF TIMER1, TIMER2 AND TIMER3 REGISTERS Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 CA2ED0 CA1ED1 CA1ED0 T16 Bit 2 Bit 1 Bit 0 Value on POR, BOR MCLR, WDT 0000 0000 16h, Bank 3 TCON1 CA2ED1 TMR3CS TMR2CS TMR1CS 0000 0000 17h, Bank 3 TCON2 CA2OVF CA1OVF PWM2ON PWM1ON CA1/PR3 TMR3ON TMR2ON TMR1ON 0000 0000 0000 0000 16h, Bank 7 TCON3 PWM3ON -000 0000 -000 0000 10h, Bank 2 TMR1 Timer1’s register xxxx xxxx uuuu uuuu 11h, Bank 2 TMR2 Timer2’s register xxxx xxxx uuuu uuuu 16h, Bank 1 PIR1 RBIF TMR3IF TMR2IF TMR1IF CA2IF 17h, Bank 1 PIE1 — CA4OVF CA3OVF CA4ED1 CA4ED0 CA3ED1 CA3ED0 CA1IF TX1IF RC1IF x000 0010 u000 0010 0000 0000 RBIE TMR3IE TMR2IE TMR1IE CA2IE CA1IE TX1IE RC1IE 0000 0000 07h, Unbanked INTSTA PEIF T0CKIF T0IF INTF PEIE T0CKIE T0IE INTE 0000 0000 0000 0000 06h, Unbanked CPUSTA — — STKAV GLINTD TO PD POR BOR --11 11qq --11 qquu 14h, Bank 2 PR1 Timer1 period register xxxx xxxx uuuu uuuu 15h, Bank 2 PR2 Timer2 period register xxxx xxxx uuuu uuuu 10h, Bank 3 PW1DCL DC1 DC0 — — — — — — xx-- ---- uu-- ---- 11h, Bank 3 PW2DCL DC1 DC0 TM2PW2 — — — — — xx0- ---- uu0- ---- 10h, Bank 7 PW3DCL DC1 DC0 TM2PW3 — — — — — xx0- ---- uu0- ---- 12h, Bank 3 PW1DCH DC9 DC8 DC7 DC6 DC5 DC4 DC3 DC2 xxxx xxxx uuuu uuuu 13h, Bank 3 PW2DCH DC9 DC8 DC7 DC6 DC5 DC4 DC3 DC2 xxxx xxxx uuuu uuuu 11h, Bank 7 PW3DCH DC9 DC8 DC7 DC6 DC5 DC4 DC3 DC2 xxxx xxxx uuuu uuuu Legend: x = unknown, u = unchanged, - = unimplemented read as a '0', q - value depends on condition, shaded cells are not used by Timer1 or Timer2. DS30289A-page 104 1998 Microchip Technology Inc. PIC17C7XX 13.1.3 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. USING PULSE WIDTH MODULATION (PWM) OUTPUTS WITH TIMER1 AND TIMER2 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 10-bits. 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 13-6: SIMPLIFIED PWM BLOCK DIAGRAM PWxDCH PWxDCL<7:6> Write (Slave) Read Duty Cycle registers Figure 13-6 shows a simplified block diagram of a PWM module. The duty cycle registers are double buffered for glitch free operation. Figure 13-7 shows how a glitch could occur if the duty cycle registers were not double buffered. PWMx Comparator TMRx Comparator PRy R (Note 1) Q S 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 13-7: PWM OUTPUT (NOT BUFFERED) 0 10 20 30 40 0 10 20 30 40 0 PWM output Timer interrupt Note Write new PWM Duty Cycle value Timer interrupt new PWM Duty Cycle value transferred to slave 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. 1998 Microchip Technology Inc. DS30289A-page 105 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 time-base. 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. If DCx = 0, then the duty cycle is zero. If PRx = PWxDCH, then the PWM output will be low for one to four Q-clock (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: 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. 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 transfered 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. 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 TABLE 13-4: 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 = OSC ) ( FFPWM bits log (2) where: FPWM = 1 / period of PWM The PWMx duty cycle is as follows: PWM Frequency PRx Value High Resolution Standard Resolution 13.1.3.2 PWM FREQUENCY vs. RESOLUTION AT 33 MHz Frequency (kHz) 32.2 64.5 90.66 128.9 515.6 0xFF 10-bit 0x7F 0x5A 9-bit 8.5-bit 0x3F 8-bit 0x0F 6-bit 8-bit 7-bit 6-bit 4-bit 6.5-bit PWM INTERRUPTS The PWM modules makes 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 roll-over. 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. PWMx Duty Cycle =(DCx) x TOSC where DCx represents PWxDCH:PWxDCL. DS30289A-page 106 the 10-bit value from 1998 Microchip Technology Inc. PIC17C7XX 13.1.3.3 13.1.3.3.1 MAX RESOLUTION/FREQUENCY FOR EXTERNAL CLOCK INPUT EXTERNAL CLOCK SOURCE 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. 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, as shown in Table 13-4 (standard resolution mode). 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). TABLE 13-5: REGISTERS/BITS ASSOCIATED WITH PWM Address Name Bit 7 Bit 6 Bit 5 Bit 4 16h, Bank 3 TCON1 CA2ED1 CA2ED0 17h, Bank 3 TCON2 CA2OVF CA1OVF PWM2ON PWM1ON CA1ED1 CA1ED0 — CA4OVF CA3OVF CA4ED0 CA4ED1 MCLR, WDT Bit 2 Bit 1 T16 TMR3CS TMR2CS TMR1CS 0000 0000 0000 0000 CA1/PR3 TMR3ON TMR2ON TMR1ON 0000 0000 0000 0000 PWM3ON -000 0000 -000 0000 CA3ED1 CA3ED0 Bit 0 Value on POR, BOR Bit 3 16h, Bank 7 TCON3 10h, Bank 2 TMR1 Timer1’s register 11h, Bank 2 TMR2 Timer2’s register 16h, Bank 1 PIR1 RBIF TMR3IF TMR2IF TMR1IF CA2IF CA1IF TX1IF RC1IF x000 0010 u000 0010 17h, Bank 1 PIE1 RBIE TMR3IE TMR2IE TMR1IE CA2IE CA1IE TX1IE RC1IE 0000 0000 0000 0000 07h, Unbanked INTSTA PEIF T0CKIF T0IF INTF PEIE T0CKIE T0IE INTE 0000 0000 0000 0000 06h, Unbanked CPUSTA — — STKAV GLINTD TO PD POR BOR --11 11qq --11 qquu xxxx xxxx uuuu uuuu xxxx xxxx uuuu uuuu 14h, Bank 2 PR1 Timer1 period register 15h, Bank 2 PR2 Timer2 period register 10h, Bank 3 PW1DCL DC1 DC0 — — — — — — xx-- ---- uu-- ---- 11h, Bank 3 PW2DCL DC1 DC0 TM2PW2 — — — — — xx0- ---- uu0- ---- 10h, Bank 7 PW3DCL DC1 DC0 TM2PW3 — — — — — xx0- ---- uu0- ---- 12h, Bank 3 PW1DCH DC9 DC8 DC7 DC6 DC5 DC4 DC3 DC2 xxxx xxxx uuuu uuuu 13h, Bank 3 PW2DCH DC9 DC8 DC7 DC6 DC5 DC4 DC3 DC2 xxxx xxxx uuuu uuuu 11h, Bank 7 PW3DCH DC9 DC8 DC7 DC6 DC5 DC4 DC3 DC2 xxxx xxxx uuuu uuuu Legend: 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. 1998 Microchip Technology Inc. DS30289A-page 107 PIC17C7XX 13.2 Timer3 (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: 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. 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 13-8 and Figure 13-9 show the block diagrams for the two modes of operation. 13.2.1 Timer3 has two modes of operation, depending on the CA1/PR3 bit (TCON2<3>). These modes are: 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 13-8. 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. • 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 FIGURE 13-8: TIMER3 WITH THREE CAPTURE AND ONE PERIOD REGISTER BLOCK DIAGRAM TMR3CS (TCON1<2>) PR3H/CA1H PR3L/CA1L Comparator x16 Comparator<8> 0 Fosc/4 TMR3H 1 Set TMR3IF (PIR1<6>) Equal Reset TMR3L TMR3ON (TCON2<2>) 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>) Edge select, Prescaler select RE3/CAP4 2 CA4ED1: CA4ED0 (TCON3<4:3>) DS30289A-page 108 Capture2 Enable CA2H CA2L Set CA2IF (PIR1<3>) Capture3 Enable CA3H CA3L Set CA3IF (PIR2<2>) Capture4 Enable CA4H CA4L Set CA4IF (PIR2<3>) 1998 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. 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 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. 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. 1998 Microchip Technology Inc. DS30289A-page 109 PIC17C7XX 13.2.2 All the captures operate in the same manner. Refer to Section 13.2.1 for the operation of capture. FOUR CAPTURE MODE This mode is selected by setting bit CA1/PR3. A block diagram is shown in Figure 13-9. 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. FIGURE 13-9: TIMER3 WITH FOUR CAPTURES BLOCK DIAGRAM Fosc/4 Set TMR3IF (PIR1<6>) 0 TMR3H 1 RB5/TCLK3 TMR3CS (TCON1<2>) TMR3L TMR3ON (TCON2<2>) Edge Select, Prescaler Select RB0/CAP1 2 Capture1 Enable Set CA1IF (PIR1<2>) PR3H/CA1H PR3L/CA1L CA1ED1, CA1ED0 (TCON1<5:4>) Edge Select, Prescaler Select RB1/CAP2 2 CA2ED1, CA2ED0 (TCON1<7:6>) Edge Select, Prescaler Select RG4/CAP3 2 Capture2 Enable Set CA2IF (PIR1<3>) CA2H CA2L Capture3 Enable Set CA3IF (PIR2<2>) CA3H CA3L CA3ED1: CA3ED0 (TCON3<2:1>) Edge Select, Prescaler Select RE3/CAP4 2 Capture4 Enable Set CA4IF (PIR2<3>) CA4H CA4L CA4ED1: CA4ED0 (TCON3<4:3>) DS30289A-page 110 1998 Microchip Technology Inc. PIC17C7XX 13.2.3 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. READING THE CAPTURE REGISTERS 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 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. EXAMPLE 13-1: SEQUENCE TO READ CAPTURE REGISTERS MOVLB MOVPF MOVPF MOVPF 3 CA2L, LO_BYTE CA2H, HI_BYTE TCON2, STAT_VAL TABLE 13-6: Address ; ; ; ; 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 REGISTERS ASSOCIATED WITH CAPTURE Name Bit 7 Bit 6 Bit 5 16h, Bank 3 TCON1 CA2ED1 CA2ED0 CA1ED1 17h, Bank 3 TCON2 CA2OVF CA1OVF PWM2ON 16h, Bank 7 TCON3 12h, Bank 2 TMR3L 13h, Bank 2 TMR3H 16h, Bank 1 PIR1 — CA4OVF CA3OVF Value on POR, BOR MCLR, WDT 0000 0000 0000 0000 PWM1ON CA1/PR3 TMR3ON TMR2ON TMR1ON 0000 0000 0000 0000 Bit 4 Bit 3 CA1ED0 T16 CA4ED1 Bit 2 Bit 1 Bit 0 TMR3CS TMR2CS TMR1CS CA4ED0 CA3ED1 CA3ED0 PWM3ON -000 0000 -000 0000 Holding register for the low byte of the 16-bit TMR3 register xxxx xxxx uuuu uuuu Holding register for the high byte of the 16-bit TMR3 register xxxx xxxx uuuu uuuu RBIF TMR3IF TMR2IF TMR1IF CA2IF CA1IF TX1IF RC1IF x000 0010 u000 0010 0000 0000 17h, Bank 1 PIE1 RBIE TMR3IE TMR2IE TMR1IE CA2IE CA1IE TX1IE RC1IE 0000 0000 10h, Bank 4 PIR2 SSPIF BCLIF ADIF — CA4IF CA3IF TX2IF RC2IF 000- 0010 000- 0010 11h, Bank 4 PIE2 SSPIE BCLIE ADIE — CA4IE CA3IE TX2IE RC2IE 000- 0000 000- 0000 07h, Unbanked INTSTA PEIF T0CKIF T0IF INTF PEIE T0CKIE T0IE INTE 0000 0000 0000 0000 06h, Unbanked CPUSTA — — STKAV GLINTD TO PD POR BOR --11 11qq --11 qquu 16h, Bank 2 PR3L/CA1L xxxx xxxx uuuu uuuu 17h, Bank 2 PR3H/CA1H Timer3 period register, high byte/capture1 register, high byte xxxx xxxx uuuu uuuu 14h, Bank 3 CA2L Capture2 low byte xxxx xxxx uuuu uuuu 15h, Bank 3 CA2H Capture2 high byte xxxx xxxx uuuu uuuu 12h, Bank 7 CA3L Capture3 low byte xxxx xxxx uuuu uuuu 13h, Bank 7 CA3H Capture3 high byte xxxx xxxx uuuu uuuu 14h, Bank 7 CA4L Capture4 low byte xxxx xxxx uuuu uuuu 15h, Bank 7 CA4H Capture4 high byte xxxx xxxx uuuu uuuu Legend: Timer3 period register, low byte/capture1 register, low byte x = unknown, u = unchanged, - = unimplemented read as '0', q - value depends on condition, shaded cells are not used by Capture. 1998 Microchip Technology Inc. DS30289A-page 111 PIC17C7XX 13.2.4 13.2.5 EXTERNAL CLOCK INPUT FOR TIMER3 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 free-running, care must be taken. For writing to the 16-bit TMR3, Example 13-2 may be used. For reading the 16-bit 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 13-10 shows the timing diagram when operating from an external clock. EXAMPLE 13-2: WRITING TO TMR3 BSF MOVFP MOVFP BCF CPUSTA, RAM_L, RAM_H, CPUSTA, GLINTD TMR3L TMR3H GLINTD ; Disable interrupts ; ; ; Done, enable interrupts EXAMPLE 13-3: READING FROM TMR3 MOVPF MOVPF MOVFP CPFSLT RETURN MOVPF MOVPF RETURN TMR3L, TMPLO TMR3H, TMPHI TMPLO, WREG TMR3L TMR3L, TMPLO TMR3H, TMPHI ; ; ; ; ; ; ; ; read low TMR3 read high TMR3 tmplo −> wreg TMR3L < wreg? no then return read low TMR3 read high TMR3 return FIGURE 13-10: TIMER1, TIMER2, AND TIMER3 OPERATION (IN COUNTER 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 TCLK12 or TCLK3 TMR1, TMR2, or TMR3 34h PR1, PR2, or PR3H:PR3L 'A9h' 35h A8h A9h 00h 'A9h' WR_TMR RD_TMR TMRxIF Instruction executed MOVWF TMRx MOVFP TMRx,W MOVFP TMRx,W Write to TMRx Read TMRx Read TMRx 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. DS30289A-page 112 1998 Microchip Technology Inc. PIC17C7XX FIGURE 13-11: TIMER1, TIMER2, AND TIMER3 OPERATION (IN TIMER MODE) 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 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 AD15:AD0 ALE Instruction fetched TMR1 MOVF MOVWF MOVF TMR1, W TMR1 TMR1, W Write TMR1 Read TMR1 Read TMR1 04h 05h 03h MOVLB 3 04h BSF TCON2, 0 Stop TMR1 05h NOP 06h BCF TCON2, 0 Start TMR1 NOP 07h NOP NOP 08h NOP 00h PR1 TMR1ON WR_TMR1 WR_TCON2 TMR1IF RD_TMR1 TMR1 reads 03h 1998 Microchip Technology Inc. TMR1 reads 04h DS30289A-page 113 PIC17C7XX NOTES: DS30289A-page 114 1998 Microchip Technology Inc. PIC17C7XX 14.0 UNIVERSAL SYNCHRONOUS ASYNCHRONOUS RECEIVER TRANSMITTER (USART) MODULES TABLE 14-1: Generic name RCSTA TXSTA SPBRG RCREG TXREG 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). RCIE RCIF TXIE TXIF 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. RX/DT TX/CK USART MODULE GENERIC NAMES USART1 name USART2 name 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 FIGURE 14-1: TXSTA1 REGISTER (ADDRESS: 15h, BANK 0) TXSTA2 REGISTER (ADDRESS: 15h, BANK 4) R/W - 0 R/W - 0 R/W - 0 R/W - 0 CSRC TX9 TXEN SYNC bit7 U-0 — U-0 — R-1 TRMT 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 bit 5: TXEN: Transmit Enable bit 1 = Transmit enabled 0 = Transmit disabled SREN/CREN overrides TXEN in SYNC mode bit 4: SYNC: USART Mode Select bit (Synchronous/Asynchronous) 1 = Synchronous mode 0 = Asynchronous mode R/W - x TX9D bit0 R = Readable bit W = Writable bit -n = Value at POR reset (x = unknown) bit 3-2: Unimplemented: Read as '0' bit 1: TRMT: Transmit Shift Register (TSR) Empty bit 1 = TSR empty 0 = TSR full bit 0: TX9D: 9th bit of transmit data (can be used to calculated the parity in software) 1998 Microchip Technology Inc. DS30289A-page 115 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 FIGURE 14-2: RCSTA1 REGISTER (ADDRESS: 13h, BANK 0) RCSTA2 REGISTER (ADDRESS: 13h, BANK 4) R/W - 0 R/W - 0 R/W - 0 R/W - 0 SPEN RX9 SREN CREN bit7 U-0 — R- 0 FERR R-0 OERR R-x RX9D bit 0 R = Readable bit W = Writable bit -n = Value at POR reset (x = unknown) bit 7: SPEN: Serial Port Enable bit 1 = Configures TX/CK and RX/DT pins as serial port pins 0 = Serial port disabled bit 6: RX9: 9-bit Receive Select bit 1 = Selects 9-bit reception 0 = Selects 8-bit reception bit 5: 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: Unimplemented: Read as '0' bit 2: FERR: Framing Error bit 1 = Framing error (Updated by reading RCREG) 0 = No framing error bit 1: OERR: Overrun Error bit 1 = Overrun (Cleared by clearing CREN) 0 = No overrun error bit 0: RX9D: 9th bit of receive data (can be the software calculated parity bit) DS30289A-page 116 1998 Microchip Technology Inc. PIC17C7XX FIGURE 14-3: USART TRANSMIT Sync Master/Slave ÷4 BRG Sync/Async Sync/Async CK/TX Sync/Async TSR ÷ 16 Clock Start 0 1 • • • 7 8 Stop Load DT TXREG 0 1 ••• 7 Data Bus 8 TXEN/ Write to TXREG Bit Count Interrupt TXSTA<0> TXIE FIGURE 14-4: USART RECEIVE OSC BRG Interrupt ÷4 Master/Slave Sync CK Buffer Logic Sync/Async Async/Sync enable Bit Count ÷ 16 START Detect SPEN RX Buffer Logic RCIE Majority Detect RSR Clock Data SREN/ CREN/ Start_Bit MSb LSb Stop 8 7 • • • 1 0 FIFO Logic RX9 Async/Sync RCREG FERR FERR RX9D RX9D 7 ••• 1 0 7 ••• 1 0 Clk FIFO Data Bus 1998 Microchip Technology Inc. DS30289A-page 117 PIC17C7XX 14.1 USART Baud Rate Generator (BRG) 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. 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. 14.1.1 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. 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 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 EXAMPLE 14-1: CALCULATING BAUD RATE ERROR Desired Baud rate=Fosc / (64 (X + 1)) 9600 = 16000000 /(64 (X + 1)) X 25.042 → 25 = Calculated Baud Rate=16000000 / (64 (25 + 1)) = 9615 Error = (Calculated Baud Rate - Desired Baud Rate) Desired Baud Rate = (9615 - 9600) / 9600 = 0.16% USART2 USART1 TABLE 14-3: REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR Address Name 13h, Bank 0 15h, Bank 0 Value on POR, BOR Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 RCSTA1 SPEN RX9 SREN CREN — FERR OERR RX9D 0000 -00x 0000 -00u TXSTA1 CSRC TX9 TXEN SYNC — — TRMT TX9D 0000 --1x 0000 --1u 0000 0000 0000 0000 17h, Bank 0 SPBRG1 13h, Bank 4 RCSTA2 SPEN RX9 SREN CREN — FERR OERR RX9D 0000 -00x 0000 -00u 15h, Bank 4 TXSTA2 CSRC TX9 TXEN SYNC — — TRMT TX9D 0000 --1x 0000 --1u 17h, Bank 4 SPBRG2 0000 0000 0000 0000 Legend: Baud rate generator register MCLR, WDT Baud rate generator register x = unknown, u = unchanged, - = unimplemented read as a '0', shaded cells are not used by the Baud Rate Generator. DS30289A-page 118 1998 Microchip Technology Inc. PIC17C7XX TABLE 14-4: BAUD RATES FOR SYNCHRONOUS MODE FOSC = 33 MHz FOSC = 25 MHz FOSC = 20 MHz FOSC = 16 MHz KBAUD %ERROR SPBRG value (decimal) KBAUD %ERROR SPBRG value (decimal) KBAUD %ERROR SPBRG value (decimal) KBAUD %ERROR SPBRG value (decimal) 0.3 NA — — NA — — NA — — NA — — 1.2 NA — — NA — — NA — — NA — — 2.4 NA — — NA — — NA — — NA — — 9.6 NA — — NA — — NA — — NA — — 19.2 NA — — NA — — 19.53 +1.73 255 19.23 +0.16 207 76.8 77.10 +0.39 106 77.16 +0.47 80 76.92 +0.16 64 76.92 +0.16 51 96 95.93 -0.07 85 96.15 +0.16 64 96.15 +0.16 51 95.24 -0.79 41 300 294.64 -1.79 27 297.62 -0.79 20 294.1 -1.96 16 307.69 +2.56 12 BAUD RATE (K) 500 485.29 -2.94 16 480.77 -3.85 12 500 0 9 500 0 7 HIGH 8250 — 0 6250 — 0 5000 — 0 4000 — 0 LOW 32.22 — 255 24.41 — 255 19.53 — 255 15.625 — 255 BAUD RATE (K) FOSC = 10 MHz FOSC = 7.159 MHz FOSC = 5.068 MHz KBAUD %ERROR SPBRG value (decimal) KBAUD %ERROR SPBRG value (decimal) KBAUD %ERROR SPBRG value (decimal) 0.3 NA — — NA — — NA — — 1.2 NA — — NA — — NA — — 2.4 NA — — NA — — NA — — 9.6 9.766 +1.73 255 9.622 +0.23 185 9.6 0 131 19.2 19.23 +0.16 129 19.24 +0.23 92 19.2 0 65 76.8 75.76 -1.36 32 77.82 +1.32 22 79.2 +3.13 15 96 96.15 +0.16 25 94.20 -1.88 18 97.48 +1.54 12 300 312.5 +4.17 7 298.3 -0.57 5 316.8 +5.60 3 500 500 0 4 NA — — NA — — HIGH 2500 — 0 1789.8 — 0 1267 — 0 LOW 9.766 — 255 6.991 — 255 4.950 — 255 KBAUD %ERROR SPBRG value (decimal) %ERROR SPBRG value (decimal) KBAUD %ERROR SPBRG value (decimal) 0.3 NA — — NA — — 0.303 +1.14 26 1.2 NA — — 1.202 +0.16 207 1.170 -2.48 6 2.4 NA — — 2.404 +0.16 103 NA — — BAUD RATE (K) FOSC = 3.579 MHz FOSC = 1 MHz KBAUD FOSC = 32.768 kHz 9.6 9.622 +0.23 92 9.615 +0.16 25 NA — — 19.2 19.04 -0.83 46 19.24 +0.16 12 NA — — 76.8 74.57 -2.90 11 83.34 +8.51 2 NA — — 96 99.43 _3.57 8 NA — — NA — — 300 298.3 -0.57 2 NA — — NA — — 500 NA — — NA — — NA — — HIGH 894.9 — 0 250 — 0 8.192 — 0 LOW 3.496 — 255 0.976 — 255 0.032 — 255 1998 Microchip Technology Inc. DS30289A-page 119 PIC17C7XX TABLE 14-5: BAUD RATES FOR ASYNCHRONOUS MODE FOSC = 33 MHz FOSC = 25 MHz FOSC = 20 MHz FOSC = 16 MHz KBAUD %ERROR SPBRG value (decimal) KBAUD %ERROR SPBRG value (decimal) KBAUD %ERROR SPBRG value (decimal) 0.3 NA — — NA — — NA — — NA — — 1.2 NA — — NA — — 1.221 +1.73 255 1.202 +0.16 207 2.4 2.398 -0.07 214 2.396 0.14 162 2.404 +0.16 129 2.404 +0.16 103 9.6 9.548 -0.54 53 9.53 -0.76 40 9.469 -1.36 32 9.615 +0.16 25 19.2 19.09 -0.54 26 19.53 +1.73 19 19.53 +1.73 15 19.23 +0.16 12 BAUD RATE (K) KBAUD %ERROR SPBRG value (decimal) 76.8 73.66 -4.09 6 78.13 +1.73 4 78.13 +1.73 3 83.33 +8.51 2 96 103.12 +7.42 4 97.65 +1.73 3 104.2 +8.51 2 NA — — 300 257.81 -14.06 1 390.63 +30.21 0 312.5 +4.17 0 NA — — 500 515.62 +3.13 0 NA — — NA — — NA — — HIGH 515.62 — 0 — — 0 312.5 — 0 250 — 0 LOW 2.014 — 255 1.53 — 255 1.221 — 255 0.977 — 255 BAUD RATE (K) FOSC = 10 MHz FOSC = 7.159 MHz FOSC = 5.068 MHz KBAUD %ERROR SPBRG value (decimal) KBAUD %ERROR SPBRG value (decimal) KBAUD %ERROR SPBRG value (decimal) 0.3 NA — — NA — — 0.31 +3.13 255 1.2 1.202 +0.16 129 1.203 _0.23 92 1.2 0 65 2.4 2.404 +0.16 64 2.380 -0.83 46 2.4 0 32 9.6 9.766 +1.73 15 9.322 -2.90 11 9.9 -3.13 7 19.2 19.53 +1.73 7 18.64 -2.90 5 19.8 +3.13 3 76.8 78.13 +1.73 1 NA — — 79.2 +3.13 0 96 NA — — NA — — NA — — 300 NA — — NA — — NA — — 500 NA — — NA — — NA — — HIGH 156.3 — 0 111.9 — 0 79.2 — 0 LOW 0.610 — 255 0.437 — 255 0.309 — 255 KBAUD %ERROR SPBRG value (decimal) KBAUD %ERROR SPBRG value (decimal) KBAUD %ERROR SPBRG value (decimal) 0.3 0.301 +0.23 185 0.300 +0.16 51 0.256 -14.67 1 1.2 1.190 -0.83 46 1.202 +0.16 12 NA — — 2.4 2.432 +1.32 22 2.232 -6.99 6 NA — — 9.6 9.322 -2.90 5 NA — — NA — — 19.2 18.64 -2.90 2 NA — — NA — — BAUD RATE (K) FOSC = 3.579 MHz FOSC = 1 MHz FOSC = 32.768 kHz 76.8 NA — — NA — — NA — — 96 NA — — NA — — NA — — 300 NA — — NA — — NA — — 500 NA — — NA — — NA — — HIGH 55.93 — 0 15.63 — 0 0.512 — 0 LOW 0.218 — 255 0.061 — 255 0.002 — 255 DS30289A-page 120 1998 Microchip Technology Inc. PIC17C7XX 14.2 USART Asynchronous Mode In this mode, the USART uses standard nonreturn-to-zero (NRZ) format (one start bit, eight or nine data bits, and one stop bit). The most common data format is 8-bits. An on-chip dedicated 8-bit 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 14.2.1 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. USART ASYNCHRONOUS TRANSMITTER The USART transmitter block diagram is shown in Figure 14-3. 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. 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: 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 14-5). 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 14-6). 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. 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). 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 opposite 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 re-enabled. The TSR is not mapped in data memory, so it is not available to the user. 1998 Microchip Technology Inc. DS30289A-page 121 PIC17C7XX FIGURE 14-5: ASYNCHRONOUS MASTER TRANSMISSION Write to TXREG Word 1 BRG output (shift clock) TX (TX/CK pin) Start Bit Bit 0 Bit 1 Bit 7/8 Stop Bit Word 1 TXIF bit Word 1 Transmit Shift Reg TRMT bit FIGURE 14-6: ASYNCHRONOUS MASTER TRANSMISSION (BACK TO BACK) Write to TXREG Word 2 Word 1 BRG output (shift clock) TX (TX/CK pin) Start Bit Bit 0 TXIF bit Bit 1 Word 1 Bit 7/8 Word 1 Transmit Shift Reg. TRMT bit Stop Bit Start Bit Word 2 Bit 0 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 MCLR, WDT 16h, Bank 1 PIR1 RBIF TMR3IF TMR2IF TMR1IF CA2IF CA1IF TX1IF RC1IF x000 0010 u000 0010 17h, Bank 1 PIE1 RBIE TMR3IE TMR2IE TMR1IE CA2IE CA1IE TX1IE RC1IE 0000 0000 0000 0000 13h, Bank 0 RCSTA1 SPEN — FERR OERR RX9D 0000 -00x 0000 -00u 16h, Bank 0 TXREG1 15h, Bank 0 TXSTA1 17h, Bank 0 SPBRG1 10h, Bank 4 PIR2 SSPIF BCLIF 11h, Bank 4 PIE2 SSPIE BCLIE 13h, Bank 4 RCSTA2 SPEN RX9 16h, Bank 4 TXREG2 15h, Bank 4 TXSTA2 17h, Bank 4 SPBRG2 Legend: RX9 SREN CREN Serial port transmit register (USART1) CSRC TX9 TXEN SYNC — TRMT TX9D 0000 --1x 0000 0000 0000 0000 — CA4IF CA3IF TX2IF RC2IF 000- 0010 000- 0010 ADIE — CA4IE CA3IE TX2IE RC2IE 000- 0000 000- 0000 SREN CREN — FERR OERR RX9D 0000 -00x 0000 -00u ADIF Serial port transmit register (USART2) TX9 uuuu uuuu 0000 --1u — Baud rate generator register (USART1) CSRC xxxx xxxx TXEN SYNC Baud rate generator register (USART2) — — TRMT TX9D xxxx xxxx uuuu uuuu 0000 --1x 0000 --1u 0000 0000 0000 0000 x = unknown, u = unchanged, - = unimplemented read as a '0', shaded cells are not used for asynchronous transmission. DS30289A-page 122 1998 Microchip Technology Inc. PIC17C7XX 14.2.2 USART ASYNCHRONOUS RECEIVER Note: The receiver block diagram is shown in Figure 14-4. 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 two deep 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 resetting 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. 14.2.3 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 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. 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 14-7). The x16 clock is a free running clock, and the three sample points occur at a frequency of every 16 falling edges. FIGURE 14-7: RX PIN SAMPLING SCHEME Start bit RX (RX/DT pin) Bit0 Baud CLK for all but start bit baud CLK x16 CLK 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 2 3 Samples FIGURE 14-8: START BIT DETECT Start bit RX (RX/DT pin) x16 CLK First rising edge of x16 clock after RX pin goes low Q2, Q4 CLK RX sampled low 1998 Microchip Technology Inc. DS30289A-page 123 PIC17C7XX 7. 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. 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. 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 re-enabled. FIGURE 14-9: ASYNCHRONOUS RECEPTION Start bit RX (RX/DT pin) bit0 bit1 Start bit bit7/8 Stop bit bit0 bit7/8 Stop bit Start bit bit7/8 Rcv shift reg Rcv buffer reg Word 3 Word 2 RCREG Word 1 RCREG Read Rcv buffer reg RCREG Stop bit RCIF (interrupt flag) OERR bit CREN 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 MCLR, WDT u000 0010 16h, Bank 1 PIR1 RBIF TMR3IF TMR2IF TMR1IF CA2IF CA1IF TX1IF RC1IF x000 0010 17h, Bank 1 PIE1 RBIE TMR3IE TMR2IE TMR1IE CA2IE CA1IE TX1IE RC1IE 0000 0000 0000 0000 13h, Bank 0 RCSTA1 SPEN RX9 CREN — FERR OERR RX9D 0000 -00x 0000 -00u 14h, Bank 0 RCREG1 RX7 RX6 RX5 RX4 RX3 RX2 RX1 RX0 xxxx xxxx uuuu uuuu 15h, Bank 0 TXSTA1 CSRC TX9 TXEN SYNC — — TRMT TX9D 0000 --1x 0000 --1u 17h, Bank 0 SPBRG1 10h, Bank 4 PIR2 SSPIF BCLIF 11h, Bank 4 PIE2 SSPIE BCLIE 13h, Bank 4 RCSTA2 SPEN RX9 14h, Bank 4 RCREG2 RX7 RX6 15h, Bank 4 TXSTA2 CSRC TX9 17h, Bank 4 SPBRG2 Legend: SREN Baud rate generator register ADIF — CA4IF CA3IF ADIE — CA4IE SREN CREN — RX5 RX4 RX3 RX2 TXEN SYNC — — Baud rate generator register 0000 0000 0000 0000 000- 0010 000- 0010 TX2IF RC2IF CA3IE TX2IE RC2IE 000- 0000 000- 0000 FERR OERR RX9D 0000 -00x 0000 -00u RX1 RX0 xxxx xxxx uuuu uuuu TRMT TX9D 0000 --1x 0000 --1u 0000 0000 0000 0000 x = unknown, u = unchanged, - = unimplemented read as a '0', shaded cells are not used for asynchronous reception. DS30289A-page 124 1998 Microchip Technology Inc. PIC17C7XX 14.3 USART Synchronous Master Mode 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 14-3. The heart of the transmitter is the transmit (serial) shift register (TSR). The shift register obtains its data from the read/write transmit buffer 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 14-11). 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. tion). 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 hi-impedance 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. 2. 3. 4. 5. 6. 7. 8. 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. 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 re-enabled. 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 recep- 1998 Microchip Technology Inc. DS30289A-page 125 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 MCLR, WDT 16h, Bank 1 PIR1 RBIF TMR3IF TMR2IF TMR1IF CA2IF CA1IF TX1IF RC1IF x000 0010 u000 0010 17h, Bank 1 PIE1 RBIE TMR3IE TMR2IE TMR1IE CA2IE CA1IE TX1IE RC1IE 0000 0000 0000 0000 13h, Bank 0 RCSTA1 SPEN RX9 SREN CREN — FERR OERR RX9D 0000 -00x 0000 -00u 16h, Bank 0 TXREG1 TX7 TX6 TX5 TX4 TX3 TX2 TX1 TX0 xxxx xxxx uuuu uuuu 15h, Bank 0 TXSTA1 CSRC TX9 TXEN SYNC — — TRMT TX9D 0000 --1x 0000 --1u 17h, Bank 0 SPBRG1 0000 0000 0000 0000 10h, Bank 4 PIR2 SSPIF BCLIF — CA4IF CA3IF TX2IF RC2IF 000- 0010 000- 0010 11h, Bank 4 PIE2 SSPIE BCLIE ADIE — CA4IE CA3IE TX2IE RC2IE 000- 0000 000- 0000 13h, Bank 4 RCSTA2 SPEN RX9 SREN CREN — FERR OERR RX9D 0000 -00x 0000 -00u 16h, Bank 4 TXREG2 TX7 TX6 TX5 TX4 TX3 TX2 TX1 TX0 xxxx xxxx uuuu uuuu 15h, Bank 4 TXSTA2 CSRC TX9 TXEN SYNC — — TRMT TX9D 0000 --1x 0000 --1u 17h, Bank 4 SPBRG2 0000 0000 0000 0000 Legend: Baud rate generator register ADIF Baud rate generator register x = unknown, u = unchanged, - = unimplemented read as a '0', shaded cells are not used for synchronous master transmission. FIGURE 14-10: SYNCHRONOUS TRANSMISSION Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4 DT (RX/DT pin) bit0 bit1 bit2 Q3 Q4 Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4Q1 Q2Q3 Q4 bit7 Word 1 bit0 Word 2 CK (TX/CK pin) Write to TXREG Write word 1 Write word 2 TXIF Interrupt flag TRMT TXEN '1' FIGURE 14-11: SYNCHRONOUS TRANSMISSION (THROUGH TXEN) DT (RX/DT pin) bit0 bit1 bit2 bit6 bit7 CK (TX/CK pin) Write to TXREG TXIF bit TRMT bit DS30289A-page 126 1998 Microchip Technology Inc. PIC17C7XX 14.3.2 Steps to follow when setting up a Synchronous Master Reception: USART SYNCHRONOUS MASTER RECEPTION 1. 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. 2. 3. 4. 5. 6. 7. 8. 9. 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. 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. FIGURE 14-12: 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) bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7 CK (TX/CK pin) Write to the SREN bit SREN bit CREN bit '0' '0' RCIF bit Read RCREG Note: Timing diagram demonstrates SYNC master mode with SREN = 1. 1998 Microchip Technology Inc. DS30289A-page 127 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 MCLR, WDT u000 0010 16h, Bank 1 PIR1 RBIF TMR3IF TMR2IF TMR1IF CA2IF CA1IF TX1IF RC1IF x000 0010 17h, Bank 1 PIE1 RBIE TMR3IE TMR2IE TMR1IE CA2IE CA1IE TX1IE RC1IE 0000 0000 0000 0000 13h, Bank 0 RCSTA1 SPEN RX9 CREN — FERR OERR RX9D 0000 -00x 0000 -00u 14h, Bank 0 RCREG1 RX7 RX6 RX5 RX4 RX3 RX2 RX1 RX0 xxxx xxxx uuuu uuuu 15h, Bank 0 TXSTA1 CSRC TX9 TXEN SYNC — — TRMT TX9D 0000 --1x 0000 --1u 17h, Bank 0 SPBRG1 10h, Bank 4 PIR2 SSPIF BCLIF 11h, Bank 4 PIE2 SSPIE BCLIE 13h, Bank 4 RCSTA2 SPEN RX9 14h, Bank 4 RCREG2 RX7 RX6 15h, Bank 4 TXSTA2 CSRC TX9 17h, Bank 4 SPBRG2 Legend: SREN Baud rate generator register ADIF — CA4IF CA3IF ADIE — CA4IE SREN CREN — RX5 RX4 RX3 RX2 TXEN SYNC — — 0000 0000 0000 0000 000- 0010 000- 0010 TX2IF RC2IF CA3IE TX2IE RC2IE 000- 0000 000- 0000 FERR OERR RX9D 0000 -00x 0000 -00u RX1 RX0 xxxx xxxx uuuu uuuu TRMT TX9D 0000 --1x 0000 --1u 0000 0000 0000 0000 Baud rate generator register x = unknown, u = unchanged, - = unimplemented read as a '0', shaded cells are not used for synchronous master reception. DS30289A-page 128 1998 Microchip Technology Inc. PIC17C7XX 14.4 USART Synchronous Slave Mode 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. 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 interrupt vector (0020h). Steps to follow when setting up a Synchronous Slave Transmission: 1. 2. 3. 4. 5. 6. 7. 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. 14.4.2 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. 2. 3. 4. 5. 6. 7. 8. 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. 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 re-enabled. 1998 Microchip Technology Inc. DS30289A-page 129 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 MCLR, WDT 16h, Bank 1 PIR1 RBIF TMR3IF TMR2IF TMR1IF CA2IF CA1IF TX1IF RC1IF x000 0010 u000 0010 17h, Bank 1 PIE1 RBIE TMR3IE TMR2IE TMR1IE CA2IE CA1IE TX1IE RC1IE 0000 0000 0000 0000 13h, Bank 0 RCSTA1 SPEN RX9 SREN CREN — FERR OERR RX9D 0000 -00x 0000 -00u 15h, Bank 0 TXSTA1 CSRC TX9 TXEN SYNC — — TRMT TX9D 0000 --1x 0000 --1u 16h, Bank 0 TXREG1 TX7 TX6 TX5 TX4 TX3 TX2 TX1 TX0 xxxx xxxx uuuu uuuu 17h, Bank 0 SPBRG1 10h, Bank 4 PIR2 SSPIF BCLIF 11h, Bank 4 PIE2 SSPIE BCLIE 13h, Bank 4 RCSTA2 SPEN RX9 16h, Bank 4 TXREG2 TX7 TX6 15h, Bank 4 TXSTA2 CSRC TX9 17h, Bank 4 SPBRG2 Legend: Baud rate generator register ADIF — CA4IF CA3IF ADIE — CA4IE SREN CREN — TX5 TX4 TXEN SYNC 0000 0000 0000 0000 TX2IF RC2IF 000- 0010 000- 0010 CA3IE TX2IE RC2IE 000- 0000 000- 0000 FERR OERR RX9D 0000 -00x 0000 -00u TX3 TX2 TX1 TX0 xxxx xxxx uuuu uuuu — — TRMT TX9D 0000 --1x 0000 --1u 0000 0000 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 MCLR, WDT 16h, Bank1 PIR1 RBIF TMR3IF TMR2IF TMR1IF CA2IF CA1IF TX1IF RC1IF x000 0010 17h, Bank1 PIE1 RBIE TMR3IE TMR2IE TMR1IE CA2IE CA1IE TX1IE RC1IE 0000 0000 0000 0000 13h, Bank0 RCSTA1 SPEN RX9 CREN — FERR OERR RX9D 0000 -00x 0000 -00u 14h, Bank0 RCREG1 RX7 RX6 RX5 RX4 RX3 RX2 RX1 RX0 xxxx xxxx uuuu uuuu 15h, Bank 0 TXSTA1 CSRC TX9 TXEN SYNC — — TRMT TX9D 0000 --1x 0000 --1u 17h, Bank 0 SPBRG1 10h, Bank 4 PIR2 SSPIF BCLIF 11h, Bank 4 PIE2 SSPIE BCLIE 13h, Bank 4 RCSTA2 SPEN RX9 14h, Bank 4 RCREG2 RX7 RX6 15h, Bank 4 TXSTA2 CSRC TX9 17h, Bank 4 SPBRG2 Legend: SREN Baud rate generator register ADIF — CA4IF CA3IF ADIE — CA4IE SREN CREN — RX5 RX4 RX3 RX2 TXEN SYNC — — u000 0010 0000 0000 0000 0000 000- 0010 000- 0010 TX2IF RC2IF CA3IE TX2IE RC2IE 000- 0000 000- 0000 FERR OERR RX9D 0000 -00x 0000 -00u RX1 RX0 xxxx xxxx uuuu uuuu TRMT TX9D 0000 --1x 0000 --1u 0000 0000 0000 0000 Baud rate generator register x = unknown, u = unchanged, - = unimplemented read as a '0', shaded cells are not used for synchronous slave reception. DS30289A-page 130 1998 Microchip Technology Inc. PIC17C7XX 15.0 MASTER SYNCHRONOUS SERIAL PORT (MSSP) MODULE The Master Synchronous Serial Port (MSSP) module is a serial interface useful for communicating with other peripheral or microcontroller devices. These peripheral devices may be serial EEPROMs, shift registers, display drivers, A/D converters, etc. The MSSP module can operate in one of two modes: • Serial Peripheral Interface (SPI) • Inter-Integrated Circuit (I 2C) FIGURE 15-2: I2C SLAVE MODE BLOCK DIAGRAM Internal data bus Read Write SSPBUF reg SCL shift clock SSPSR reg SDA MSb Figure 15-1 shows a block diagram for the SPI mode, while Figure 15-2, and Figure 15-3 shows the block diagrams for the two different I2C modes of operation. Addr Match or General Call detected Match detect FIGURE 15-1: SPI MODE BLOCK DIAGRAM SSPADD reg Internal data bus Read LSb Set, Reset S, P bits (SSPSTAT reg) Start and Stop bit detect Write FIGURE 15-3: I2C MASTER MODE BLOCK DIAGRAM SSPBUF reg Internal data bus SSPSR reg SDI shift clock bit0 SSPBUF reg SCL SS Control Enable shift clock Edge Select SSPSR reg SDA 2 Clock Select SCK Write Baud Rate Generator SDO SS Read SSPADD<6:0> 7 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 1998 Microchip Technology Inc. MSb LSb Addr Match or General Call detected Match detect SSPADD reg Start and Stop bit detect / generate Set/Clear S bit and Clear/Set P, bit (SSPSTAT reg) and Set SSPIF DS30289A-page 131 PIC17C7XX FIGURE 15-4: SSPSTAT: SYNC SERIAL PORT STATUS REGISTER (ADDRESS: 13h, BANK 6) R/W-0 R/W-0 R-0 R-0 R-0 R-0 R-0 R-0 SMP CKE D/A P S R/W UA BF bit7 bit 7: bit0 R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR reset 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 I2C 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 15-9, Figure 15-11, and Figure 15-12) 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 bit 4: 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 bit 3: 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 bit 2: 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 I2C slave mode: 1 = Read 0 = Write In I2C 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 bit 0: 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 DS30289A-page 132 1998 Microchip Technology Inc. PIC17C7XX FIGURE 15-5: SSPCON1: SYNC SERIAL PORT CONTROL REGISTER1 (ADDRESS 11h, BANK 6) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 bit7 bit0 R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR reset bit 7: 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 bit 6: 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 I2C 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 bit 5: 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 I2C 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: bit 4: 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 I2C slave mode SCK release control 1 = Enable clock 0 = Holds clock low (clock stretch) (Used to ensure data setup time) In I2C master mode Unused in this mode bit 3-0: 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 1998 Microchip Technology Inc. DS30289A-page 133 PIC17C7XX FIGURE 15-6: SSPCON2: SYNC SERIAL PORT CONTROL REGISTER2 (ADDRESS 12h, BANK 6) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN bit7 bit0 R = Readable bit W = Writable bit U = Unimplemented bit, Read as ‘0’ - n = Value at POR reset 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. bit 6: 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: RCEN: Receive Enable bit (In I2C master mode only). 1 = Enables Receive mode for I2C 0 = Receive idle Note: bit 2: 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). 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: bit 0: 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). 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: bit 1: 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). 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) 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: DS30289A-page 134 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). 1998 Microchip Technology Inc. PIC17C7XX 15.1 SPI Mode The SPI mode allows 8-bits of data to be synchronously transmitted and received simultaneously. All four modes of SPI are supported. To accomplish communication, typically three pins are used: FIGURE 15-7: MSSP BLOCK DIAGRAM (SPI MODE) Internal data bus Read • Serial Data Out (SDO) • Serial Data In (SDI) • Serial Clock (SCK) Write SSPBUF reg Additionally a fourth pin may be used when in a slave mode of operation: • Slave Select (SS) 15.1.1 SSPSR reg SDI shift clock bit0 OPERATION SDO 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: SS Control Enable SS • • • • 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 15-7 shows the block diagram of the MSSP module when in SPI mode. Edge Select 2 Clock Select SCK 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 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. 1998 Microchip Technology Inc. DS30289A-page 135 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. EXAMPLE 15-1: LOADING THE SSPBUF (SSPSR) REGISTER MOVLB 6 LOOP BTFSS SSPSTAT, BF ; ; ; ; ; GOTO LOOP ; MOVPF SSPBUF, RXDATA ; MOVFP TXDATA, SSPBUF ; 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 Any serial port function that is not desired may be overridden by programming the corresponding data direction (DDR) register to the opposite value. Bank 6 Has data been received (transmit complete)? No Save in user RAM New data to xmit 15.1.3 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. TYPICAL CONNECTION Figure 15-8 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 15-8: SPI MASTER/SLAVE CONNECTION SPI Master SSPM3:SSPM0 = 00xxb SPI Slave SSPM3:SSPM0 = 010xb SDO SDI Serial Input Buffer (SSPBUF) Serial Input Buffer (SSPBUF) SDI Shift Register (SSPSR) MSb SDO LSb Shift Register (SSPSR) MSb LSb Serial Clock SCK PROCESSOR 1 DS30289A-page 136 SCK PROCESSOR 2 1998 Microchip Technology Inc. PIC17C7XX 15.1.4 MSb is transmitted first. In master mode, the SPI clock rate (bit rate) is user programmable to be one of the following: 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 15-8) 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. 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 15-9 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. The clock polarity is selected by appropriately programming bit CKP (SSPCON1<4>). This then would give waveforms for SPI communication as shown in Figure 15-9, Figure 15-11, and Figure 15-12 where the FIGURE 15-9: SPI MODE WAVEFORM (MASTER MODE) Write to SSPBUF SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) 4 clock modes SCK (CKP = 0 CKE = 1) SCK (CKP = 1 CKE = 1) SDO (CKE = 0) bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 SDO (CKE = 1) bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 SDI (SMP = 0) bit0 bit7 Input Sample (SMP = 0) SDI (SMP = 1) bit7 bit0 Input Sample (SMP = 1) SSPIF SSPSR to SSPBUF 1998 Microchip Technology Inc. Next Q4 cycle after Q2↓ DS30289A-page 137 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. 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 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: 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. Note: 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. FIGURE 15-10: SLAVE SYNCHRONIZATION WAVEFORM SS SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) Write to SSPBUF SDO SDI (SMP = 0) bit7 bit6 bit7 bit0 bit0 bit7 bit7 Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF DS30289A-page 138 Next Q4 cycle after Q2↓ 1998 Microchip Technology Inc. PIC17C7XX FIGURE 15-11: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0) SS optional SCK (CKP = 0 CKE = 0) SCK (CKP = 1 CKE = 0) Write to SSPBUF SDO SDI (SMP = 0) bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 bit0 bit7 Input Sample (SMP = 0) SSPIF Interrupt Flag Next Q4 cycle after Q2↓ SSPSR to SSPBUF FIGURE 15-12: SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1) SS not optional SCK (CKP = 0 CKE = 1) SCK (CKP = 1 CKE = 1) Write to SSPBUF SDO SDI (SMP = 0) bit7 bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0 bit0 Input Sample (SMP = 0) SSPIF Interrupt Flag SSPSR to SSPBUF 1998 Microchip Technology Inc. Next Q4 cycle after Q2↓ DS30289A-page 139 PIC17C7XX 15.1.7 15.1.8 SLEEP OPERATION EFFECTS OF A RESET A reset disables the MSSP module and terminates the current transfer. 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. TABLE 15-1: REGISTERS ASSOCIATED WITH SPI OPERATION Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 POR, BOR MCLR, WDT 07h, Unbanked INTSTA PEIF T0CKIF T0IF INTF PEIE T0CKIE T0IE INTE 0000 0000 0000 0000 10h, Bank 4 PIR2 SSPIF BCLIF ADIF — CA4IF CA3IF TX2IF RC2IF 000- 0010 000- 0010 11h, Bank 4 PIE2 SSPIE BCLIE ADIE — CA4IE CA3IE TX2IE RC2IE 000- 0000 000- 0000 14h, Bank 6 SSPBUF Synchronous Serial Port Receive Buffer/Transmit Register 11h, Bank 6 SSPCON1 WCOL SSPOV SSPEN 13h, Bank 6 SSPSTAT SMP CKE D/A CKP P xxxx xxxx uuuu uuuu SSPM3 SSPM2 SSPM1 S R/W UA 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. DS30289A-page 140 1998 Microchip Technology Inc. PIC17C7XX 15.2 MSSP I 2C Operation I 2C The MSSP module in 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. Appendix E: gives an overview of the I 2C bus specification. FIGURE 15-14: I2C MASTER MODE BLOCK DIAGRAM Internal data bus Read SSPADD<6:0> 7 Write Baud Rate Generator Refer to Application Note AN578, "Use of the SSP Module in the I 2C Multi-Master Environment." SSPBUF reg SCL shift clock 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 independant of device frequency. SSPSR reg SDA MSb LSb FIGURE 15-13: I2C SLAVE MODE BLOCK DIAGRAM Match detect Internal data bus SSPADD reg Read Write Start and Stop bit detect / generate SSPBUF reg SCL shift clock SSPSR reg SDA MSb LSb Match detect Addr Match Set/Clear S bit and Clear/Set P, bit (SSPSTAT reg) and Set SSPIF 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 that 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 Addr Match 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. 1998 Microchip Technology Inc. DS30289A-page 141 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. 15.2.1 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. 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. 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). 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 (slave-transmitter). 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 is shown in timing parameter #100 and parameter #101 of the Electrical Specifications. DS30289A-page 142 1998 Microchip Technology Inc. PIC17C7XX 15.2.1.1 5. ADDRESSING Once the MSSP module has been enabled, it waits for a START condition to occur. Following the START condition, the 8-bits are shifted into the 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) b) c) d) 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. 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. 3. 4. 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). TABLE 15-2: 6. 7. 8. 9. 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: 15.2.1.2 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. SLAVE RECEPTION 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 occured. The ACK is not sent and the SSPBUF is updated. DATA TRANSFER RECEIVED BYTE ACTIONS Status Bits as Data Transfer is Received BF SSPOV SSPSR → SSPBUF Generate ACK Pulse Set bit SSPIF (SSP Interrupt occurs if enabled) 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. 1998 Microchip Technology Inc. DS30289A-page 143 PIC17C7XX 15.2.1.3 As a slave-transmitter, the ACK pulse from the master-receiver 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. 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 SCLpin 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 15-16). 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 tranfer. The SSPIF flag bit is set on the falling edge of the ninth clock pulse. FIGURE 15-15: I 2C WAVEFORMS FOR RECEPTION (7-BIT ADDRESS) R/W=0 ACK Receiving Address A7 A6 A5 A4 A3 A2 A1 SDA SCL 1 S 2 3 4 5 6 7 Not Receiving Data Receiving Data ACK ACK D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0 1 9 8 2 3 4 5 6 7 8 9 1 2 3 4 5 8 7 6 9 SSPIF P Bus Master terminates transfer BF (SSPSTAT<0>) Cleared in software SSPBUF register is read SSPOV (SSPCON1<6>) Bit SSPOV is set because the SSPBUF register is still full. ACK is not sent. FIGURE 15-16: I 2C WAVEFORMS FOR TRANSMISSION (7-BIT ADDRESS) R/W = 1 ACK Receiving Address SDA SCL A7 S A6 1 2 Data in sampled A5 A4 A3 A2 A1 3 4 5 6 7 D7 8 9 R/W = 0 Not ACK Transmitting Data 1 SCL held low while CPU responds to SSPIF D6 D5 D4 D3 D2 D1 D0 2 3 4 5 6 7 8 9 P SSPIF BF (SSPSTAT<0>) cleared in software SSPBUF is written in software From SSP interrupt service routine CKP (SSPCON1<4>) Set bit after writing to SSPBUF (the SSPBUF must be written-to before the CKP bit can be set) DS30289A-page 144 1998 Microchip Technology Inc. 1998 Microchip Technology Inc. UA (SSPSTAT<1>) BF (SSPSTAT<0>) (PIR1<3>) SSPIF 1 S SCL 2 1 4 1 5 0 6 7 A9 A8 UA is set indicating that the SSPADD needs to be updated SSPBUF is written with contents of SSPSR 3 1 8 9 ACK Receive First Byte of Address R/W = 0 1 SDA 1 3 4 5 Cleared in software 2 7 UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated. 6 A6 A5 A4 A3 A2 A1 8 A0 Receive Second Byte of Address Dummy read of SSPBUF to clear BF flag A7 Clock is held low until update of SSPADD has taken place 9 ACK 2 3 1 4 1 Cleared in software 1 1 Cleared by hardware when SSPADD is updated. Dummy read of SSPBUF to clear BF flag Sr 1 5 0 6 7 A9 A8 Receive First Byte of Address 8 9 R/W=1 ACK 1 3 4 5 6 7 8 9 ACK P Write of SSPBUF initiates transmit Cleared in software Bus Master terminates transfer CKP has to be set for clock to be released 2 D4 D3 D2 D1 D0 Transmitting Data Byte D7 D6 D5 Master sends NACK Transmit is complete PIC17C7XX FIGURE 15-17: I2C SLAVE-TRANSMITTER (10-BIT ADDRESS) DS30289A-page 145 DS30289A-page 146 UA (SSPSTAT<1>) BF (SSPSTAT<0>) (PIR1<3>) SSPIF 1 SCL S 1 SDA 2 1 3 1 5 0 6 A9 7 A8 UA is set indicating that the SSPADD needs to be updated 8 9 ACK R/W = 0 SSPBUF is written with contents of SSPSR 4 1 Receive First Byte of Address 1 3 A5 4 A4 Cleared in software 2 A6 5 A3 6 A2 7 A1 8 A0 UA is set indicating that SSPADD needs to be updated Cleared by hardware when SSPADD is updated with low byte of address. Dummy read of SSPBUF to clear BF flag A7 Receive Second Byte of Address Clock is held low until update of SSPADD has taken place 9 ACK 3 D5 4 D4 5 D3 Cleared in software 2 D6 Cleared by hardware when SSPADD is updated with high byte of address. Dummy read of SSPBUF to clear BF flag 1 D7 Receive Data Byte 6 D2 7 D1 8 D0 9 ACK R/W = 1 Read of SSPBUF clears BF flag P Bus Master terminates transfer PIC17C7XX FIGURE 15-18: I2C SLAVE-RECEIVER (10-BIT ADDRESS) 1998 Microchip Technology Inc. PIC17C7XX 15.2.2 If the general call address matches, the SSPSR is transfered 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. 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. 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 15-19). 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. FIGURE 15-19: 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 General Call Address SDA Receiving data ACK D6 D5 D4 D3 D2 D1 D0 2 3 4 5 6 7 8 SCL S 1 2 3 4 5 6 7 8 9 1 9 SSPIF BF (SSPSTAT<0>) Cleared in software SSPBUF is read SSPOV (SSPCON1<6>) '0' GCEN (SSPCON2<7>) '1' 1998 Microchip Technology Inc. DS30289A-page 147 PIC17C7XX 15.2.3 15.2.4 SLEEP OPERATION 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). TABLE 15-3: Address EFFECTS OF A RESET A reset diables the SSP module and terminates the current transfer. REGISTERS ASSOCIATED WITH I2C OPERATION Name 07h, Unbanked INTSTA Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 POR, BOR MCLR, WDT PEIF T0CKIF T0IF INTF PEIE T0CKIE T0IE INTE 0000 0000 0000 0000 10h, Bank 4 PIR2 SSPIF BCLIF ADIF — CA4IF CA3IF TX2IF RC2IF 000- 0000 000- 0000 11h, Bank 4 PIE2 SSPIE BCLIE ADIE — CA4IE CA3IE TX2IE RC2IE 000- 0000 000- 0000 10h. Bank 6 SSPADD Synchronous Serial Port (I2C mode) Address Register 0000 0000 0000 0000 14h, Bank 6 SSPBUF Synchronous Serial Port Receive Buffer/Transmit Register xxxx xxxx uuuu uuuu 11h, Bank 6 SSPCON1 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 0000 0000 0000 0000 12h, Bank 6 SSPCON2 GCEN ACKSTAT ACKDT ACKEN RCEN PEN RSEN SEN 0000 0000 0000 0000 13h, Bank 6 SSPSTAT SMP CKE D/A P S R/W UA BF 0000 0000 0000 0000 Legend: x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used by the SSP in I2C mode. DS30289A-page 148 1998 Microchip Technology Inc. PIC17C7XX 15.2.5 MASTER MODE The following events will cause SSP Interrupt Flag bit, SSPIF, to be set (SSP Interrupt if enabled): 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. • • • • • START condition STOP condition Data transfer byte transmitted/received Acknowledge transmit Repeated Start In master mode, the SCL and SDA lines are manipulated by the MSSP hardware. FIGURE 15-20: SSP BLOCK DIAGRAM (I2C MASTER MODE) Internal data bus Read SSPM3:SSPM0 SSPADD<6:0> Write SSPBUF shift clock SDA SDA in SSPSR SCL in Bus Collision 1998 Microchip Technology Inc. LSb Start bit, Stop bit, Acknowledge Generate Start bit detect, Stop bit detect Write collision detect Clock Arbitration State counter for end of XMIT/RCV clock cntl SCL Receive Enable MSb clock arbitrate/WCOL detect (hold off clock source) Baud rate generator Set/Reset, S, P, WCOL (SSPSTAT) Set SSPIF, BCLIF Reset ACKSTAT, PEN (SSPCON2) DS30289A-page 149 PIC17C7XX 15.2.6 MULTI-MASTER MODE In multi-master mode, the interrupt generation on the detection of the START and STOP conditions allows the determination of when the bus is free. The STOP (P) and START (S) bits are cleared from a reset or when the MSSP module is disabled. Control of the I 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 abitration, 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 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. Note: 15.2.7.1 I2C MASTER MODE OPERATION The master device generates all of the serial clock pulses and the START and STOP conditions. A transfer is ended with a STOP condition or with a Repeated Start condition. Since the Repeated Start condition is also the beginning of the next serial transfer, the 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 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. DS30289A-page 150 1998 Microchip Technology Inc. PIC17C7XX A typical transmit sequence would go as follows: 15.2.8 a) In I2C master mode, the reload value for the BRG is located in the lower 7 bits of the SSPADD register (Figure 15-21). 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. b) c) d) e) f) g) h) i) j) k) l) 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. BAUD RATE GENERATOR 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 15-22). FIGURE 15-21: BAUD RATE GENERATOR BLOCK DIAGRAM SSPM3:SSPM0 SSPADD<6:0> SSPM3:SSPM0 Reload SCL Control CLKOUT Reload BRG Down Counter Fosc/4 FIGURE 15-22: BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION SDA DX DX-1 SCL de-asserted but slave holds SCL low (clock arbitration) SCL allowed to transition high 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 1998 Microchip Technology Inc. DS30289A-page 151 PIC17C7XX 15.2.9 I2C MASTER MODE START CONDITION TIMING 15.2.9.1 If the user writes the SSPBUF when an START sequence is in progress, then WCOL is set and the contents of the buffer are unchanged (the write doesn’t occur). 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 re-loaded 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: WCOL STATUS FLAG Note: Because queueing of events is not allowed, writing to the lower 5 bits of SSPCON2 is disabled until the START condition is complete. 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 15-23: FIRST START BIT TIMING Set S bit (SSPSTAT<3>) Write to SEN bit occurs here. SDA = 1, SCL = 1 TBRG At completion of start bit, Hardware clears SEN bit and sets SSPIF bit TBRG Write to SSPBUF occurs here 1st Bit SDA 2nd Bit TBRG SCL TBRG S DS30289A-page 152 1998 Microchip Technology Inc. PIC17C7XX FIGURE 15-24: START CONDITION FLOWCHART 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 No No Yes SCL= 0? SDA = 0? Yes BRG Rollover? Yes Reset BRG Force SDA = 0, Load BRG with SSPADD<6:0>, Set S bit. No SCL = 0? Yes No BRG rollover? Yes Reset BRG Force SCL = 0, Start Condition Done, Clear SEN and set SSPIF 1998 Microchip Technology Inc. DS30289A-page 153 PIC17C7XX 15.2.10 I2C MASTER MODE REPEATED START CONDITION TIMING 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 re-loaded 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. Immediately following the SSPIF bit getting set, the user may write the SSPBUF with the 7-bit address in 7-bit mode, or the default first address in 10-bit mode. After the first eight bits are transmitted and an ACK is received, the user may then transmit an additional eight bits of address (10-bit mode) or eight bits of data (7-bit mode). 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. Note 1: If the RSEN is programmed while any other event is in progress, it will not take effect. Note 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". FIGURE 15-25: REPEAT START CONDITION WAVEFORM Set S (SSPSTAT<3>) Write to SSPCON2 occurs here. SDA = 1, SCL(no change) SDA = 1, SCL = 1 TBRG At completion of start bit, hardware clear RSEN bit and set SSPIF TBRG TBRG 1st Bit SDA Falling edge of ninth clock End of Xmit SCL Write to SSPBUF occurs here. TBRG TBRG Sr = Repeated Start DS30289A-page 154 1998 Microchip Technology Inc. PIC17C7XX FIGURE 15-26: REPEATED START CONDITION FLOWCHART (PAGE 1) Start Idle Mode, SSPEN = 1, SSPCON1<3:0> = 1000 B 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 1998 Microchip Technology Inc. A DS30289A-page 155 PIC17C7XX FIGURE 15-27: REPEATED START CONDITION FLOWCHART (PAGE 2) B C A Yes No No No SDA = 0? SCL = 1? Yes BRG rollover? Yes Reset BRG Force SDA = 0, Load BRG with SSPADD<6:0> Set S No SCL = '0'? Yes Reset BRG DS30289A-page 156 No BRG rollover? Yes Force SCL = 0, Repeated Start condition done, Clear RSEN, Set SSPIF. 1998 Microchip Technology Inc. PIC17C7XX 15.2.11 I2C MASTER MODE TRANSMISSION 15.2.11.1 BF STATUS FLAG 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 15-29) 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. 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. 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. 1998 Microchip Technology Inc. DS30289A-page 157 PIC17C7XX FIGURE 15-28: MASTER TRANSMIT FLOWCHART Idle Mode Write SSPBUF Num_Clocks = 0, BF = 1 Force SCL = 0 Release SDA so slave can drive ACK, Force BF = 0 Yes Num_Clocks = 8? No Load BRG with SSPADD<6:0>, start BRG count Load BRG with SSPADD<6:0>, start BRG count, SDA = Current Data bit BRG rollover? BRG rollover? No No Yes Yes Force SCL = 1, Stop BRG Stop BRG, Force SCL = 1 (Clock Arbitration) SCL = 1? (Clock Arbitration) No SCL = 1? No Yes Yes SDA = Data bit? Read SDA and place into ACKSTAT bit (SSPCON2<6>) No Bus collision detected Set BCLIF, hold prescale off, Clear XMIT enable Yes Load BRG with SSPADD<6:0>, count high time Load BRG with SSPADD<6:0>, count SCL high time No Rollover? Yes BRG rollover? No No SCL = 0? Yes Yes SDA = Data bit? No Yes Force SCL = 0, Set SSPIF Reset BRG Num_Clocks = Num_Clocks + 1 DS30289A-page 158 1998 Microchip Technology Inc. 1998 Microchip Technology Inc. S R/W PEN SEN BF (SSPSTAT<0>) SSPIF SCL SDA A6 A5 A4 A3 A2 A1 3 4 5 cleared in software 2 6 7 8 9 After start condition SEN cleared by hardware. SSPBUF written 1 D7 3 D5 4 D4 5 D3 6 D2 7 D1 SSPBUF is written in software 8 D0 cleared in software service routine From SSP interrupt 2 D6 Transmitting Data or Second Half of 10-bit Address From slave clear ACKSTAT bit SSPCON2<6> 1 SCL held low while CPU responds to SSPIF ACK = 0 R/W = 0 SSPBUF written with 7 bit address and R/W start transmit A7 Transmit Address to Slave SEN = 0 Write SSPCON2<0> SEN = 1 START condition begins P Cleared in software 9 ACK ACKSTAT in SSPCON2 = 1 PIC17C7XX FIGURE 15-29: I 2C MASTER MODE TIMING (TRANSMISSION, 7 OR 10-BIT ADDRESS) DS30289A-page 159 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>). 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. Note: The SSP Module must be in an IDLE STATE before the RCEN bit is set, or the RCEN bit will be disregarded. 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>). DS30289A-page 160 15.2.12.2 SSPOV STATUS FLAG 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). 1998 Microchip Technology Inc. PIC17C7XX FIGURE 15-30: MASTER RECEIVER FLOWCHART Idle mode RCEN = 1 Num_Clocks = 0, Release SDA Force SCL=0, Load BRG w/ SSPADD<6:0>, start count BRG rollover? No Yes Release SCL (Clock Arbitration) SCL = 1? No Yes Sample SDA, Shift data into SSPSR Load BRG with SSPADD<6:0>, start count. BRG rollover? No Yes 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. 1998 Microchip Technology Inc. DS30289A-page 161 DS30289A-page 162 S ACKEN SSPOV BF (SSPSTAT<0>) SDA = 0, SCL = 1 while CPU responds to SSPIF SSPIF SCL SDA 1 A7 2 4 5 Cleared in software 3 6 A6 A5 A4 A3 A2 Transmit Address to Slave SEN = 0 Write to SSPBUF occurs here Start XMIT Write to SSPCON2<0> (SEN = 1) Begin Start Condition 7 A1 8 9 R/W = 1 ACK ACK from Slave 2 3 5 6 7 8 D0 9 ACK 2 3 4 5 6 7 Cleared in software Set SSPIF interrupt at end of acknowledge sequence Data shifted in on falling edge of CLK 1 D7 D6 D5 D4 D3 D2 D1 Cleared in software Set SSPIF at end of receive 9 ACK is not sent ACK P Set SSPIF interrupt at end of acknowledge sequence Bus Master terminates transfer Set P bit (SSPSTAT<4>) and SSPIF PEN bit = 1 written here SSPOV is set because SSPBUF is still full 8 D0 RCEN cleared automatically Set ACKEN start acknowledge sequence SDA = ACKDT = 1 Receiving Data from Slave RCEN = 1 start next receive ACK from Master SDA = ACKDT = 0 Last bit is shifted into SSPSR and contents are unloaded into SSPBUF Cleared in software Set SSPIF interrupt at end of receive 4 Cleared in software 1 D7 D6 D5 D4 D3 D2 D1 Receiving Data from Slave RCEN cleared automatically Master configured as a receiver by programming SSPCON2<3>, (RCEN = 1) Write to SSPCON2<4> to start acknowledge sequence SDA = ACKDT (SSPCON2<5>) = 0 PIC17C7XX FIGURE 15-31: I 2C MASTER MODE TIMING (RECEPTION 7-BIT ADDRESS) 1998 Microchip Technology Inc. PIC17C7XX 15.2.13 ACKNOWLEDGE SEQUENCE TIMING 15.2.13.1 WCOL STATUS FLAG 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 15-32) If the user writes the SSPBUF when an acknowledege sequence is in progress, then WCOL is set and the contents of the buffer are unchanged (the write doesn’t occur). FIGURE 15-32: ACKNOWLEDGE SEQUENCE WAVEFORM Acknowledge sequence starts here, Write to SSPCON2 ACKEN = 1, ACKDT = 0 ACKEN automatically cleared TBRG TBRG SDA ACK D0 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. 1998 Microchip Technology Inc. DS30289A-page 163 PIC17C7XX FIGURE 15-33: ACKNOWLEDGE FLOWCHART Idle mode Set ACKEN Force SCL = 0 BRG rollover? Yes 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 No No ACKDT = 1? Yes No BRG rollover? Yes Yes Force SCL = 1 SDA = 1? No Bus collision detected, Set BCLIF, Release SCL, Clear ACKEN No SCL = 1? (Clock Arbitration) Yes Load BRG with SSPADD <6:0>, start count. DS30289A-page 164 1998 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 15-34) 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). 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). FIGURE 15-34: STOP CONDITION RECEIVE OR TRANSMIT MODE SCL = 1 for TBRG, followed by SDA = 1 for TBRG after SDA sampled high. P bit (SSPSTAT<4>) is set Write to SSPCON2 Set PEN PEN bit (SSPCON2<2>) is cleared by hardware and the SSPIF bit is set Falling edge of 9th clock TBRG SCL 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. 1998 Microchip Technology Inc. DS30289A-page 165 PIC17C7XX FIGURE 15-35: STOP CONDITION FLOWCHART Idle Mode, SSPEN = 1, SSPCON1<3:0> = 1000 PEN = 1 Start BRG Force SDA = 0 SCL doesn’t change BRG rollover? No SDA = 0? No Yes Release SDA, Start BRG Yes Start BRG BRG rollover? BRG rollover? No No Yes No P bit Set? Yes De-assert SCL, SCL = 1 Yes (Clock Arbitration) SCL = 1? Bus Collision detected, Set BCLIF, Clear PEN No SDA going from 0 to 1 while SCL = 1 Set SSPIF, Stop Condition done PEN cleared. Yes DS30289A-page 166 1998 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 de-asserts 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 15-36) 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 15-36: 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 1998 Microchip Technology Inc. TBRG TBRG DS30289A-page 167 PIC17C7XX 15.2.18 MULTI -MASTER COMMUNICATION, BUS COLLISION, AND BUS ARBITRATION 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 15-37). 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. 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. FIGURE 15-37: 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 DS30289A-page 168 1998 Microchip Technology Inc. PIC17C7XX 15.2.18.1 BUS COLLISION DURING A START CONDITION During a START condition, a bus collision occurs if: a) SDA or SCL are sampled low at the beginning of the START condition (Figure 15-38) SCL is sampled low before SDA is asserted low. (Figure 15-39) b) During a START condition both the SDA and the SCL pins are monitored. If the SDA pin is sampled low during this count, the BRG is reset and the SDA line is asserted early (Figure 15-40). 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 pins is sampled as '0', a bus collision does not occur. At the end of the BRG count the SCL pin is asserted low. Note: 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 15-38). 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. 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. FIGURE 15-38: 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 cleared automatically because of bus collision. SSP module reset into idle state. SEN BCLIF 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 SSPIF SSPIF and BCLIF are cleared in software. 1998 Microchip Technology Inc. DS30289A-page 169 PIC17C7XX FIGURE 15-39: BUS COLLISION DURING START CONDITION (SCL = 0) SDA = 0, SCL = 1 TBRG TBRG SDA Set SEN, enable start sequence if SDA = 1, SCL = 1 SCL SCL = 0 before SDA = 0, Bus collision occurs, Set BCLIF. SEN SCL = 0 before BRG time out, Bus collision occurs, Set BCLIF. BCLIF Interrupts cleared in software. S '0' '0' SSPIF '0' '0' FIGURE 15-40: BRG RESET DUE TO SDA COLLISION DURING START CONDITION SDA = 0, SCL = 1 Set S Less than TBRG SDA SDA pulled low by other master. Reset BRG and assert SDA SCL S SCL pulled low after BRG Timeout SEN BCLIF Set SSPIF TBRG '0' Set SEN, enable start sequence if SDA = 1, SCL = 1 S SSPIF SDA = 0, SCL = 1 Set SSPIF DS30289A-page 170 Interrupts cleared in software. 1998 Microchip Technology Inc. PIC17C7XX ’0’). If however SDA is sampled high then the BRG is 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. 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’. 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. 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 de-asserted, 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 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 15-41) FIGURE 15-41: BUS COLLISION DURING A REPEATED START CONDITION (CASE 1) SDA SCL Sample SDA when SCL goes high. If SDA = 0, set BCLIF and release SDA and SCL RSEN BCLIF S '0' Cleared in software '0' SSPIF '0' '0' FIGURE 15-42: BUS COLLISION DURING REPEATED START CONDITION (CASE 2) TBRG TBRG SDA SCL SCL goes low before SDA, Set BCLIF. Release SDA and SCL BCLIF Interrupt cleared in software RSEN S '0' '0' SSPIF '0' '0' 1998 Microchip Technology Inc. DS30289A-page 171 PIC17C7XX The STOP condition begins with SDA asserted low. When SDA is sampled low, the SCL pin is allow 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 15-43) 15.2.18.3 BUS COLLISION DURING A STOP CONDITION Bus collision occurs during a STOP condition if: a) b) 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. FIGURE 15-43: BUS COLLISION DURING A STOP CONDITION (CASE 1) TBRG TBRG SDA sampled low after TBRG, Set BCLIF TBRG SDA SDA asserted low SCL PEN BCLIF P '0' '0' SSPIF '0' '0' FIGURE 15-44: BUS COLLISION DURING A STOP CONDITION (CASE 2) TBRG TBRG TBRG SDA Assert SDA SCL SCL goes low before SDA goes high Set BCLIF PEN BCLIF P '0' '0' SSPIF '0' '0' DS30289A-page 172 1998 Microchip Technology Inc. PIC17C7XX 15.3 Connection Considerations for I2C Bus For standard-mode I2C bus devices, the values of resistors Rp Rsin Figure 15-45 depends on the following parameters • Supply voltage • Bus capacitance • Number of connected devices (input current + leakage current). 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 15-45). 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). 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 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 kΩ. VDD as a function of Rp is shown in Figure 15-45. The desired noise margin of 0.1VDD for the low level, limits the maximum value of Rs. Series resistors are optional and used to improve ESD susceptibility. FIGURE 15-45: SAMPLE DEVICE CONFIGURATION FOR I2C BUS VDD + 10% Rp DEVICE Rp Rs Rs SDA SCL 2 NOTE: I C devices with input levels related to VDD must have one common supply line to which the pull up resistor is also connected. 1998 Microchip Technology Inc. Cb=10 - 400 pF DS30289A-page 173 PIC17C7XX 15.4 Example Program Example 15-2 shows MPLAB-C17 ’C’ code for using the I2C module in master mode to communicate with a 24LC01B serial EEPROM. This example uses the PICmicro ’C’ libraries included with MPLAB-C17. EXAMPLE 15-2: INTERFACING TO A 24LC01B SERIAL EEPROM (USING MPLAB-C17) // Include necessary header files #include <p17c756.h> // Processor header file #include <delays.h> // Delay routines header file #include <stdlib.h> // Standard Library header file #include <i2c16.h> // 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 } DS30289A-page 174 1998 Microchip Technology Inc. PIC17C7XX EXAMPLE 15-2: INTERFACING TO A 24LC01B SERIAL EEPROM (USING MPLAB-C17) (Cont.’d) // 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); } 1998 Microchip Technology Inc. DS30289A-page 175 PIC17C7XX EXAMPLE 15-2: INTERFACING TO A 24LC01B SERIAL EEPROM (USING MPLAB-C17) (Cont.’d) 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; } DS30289A-page 176 1998 Microchip Technology Inc. PIC17C7XX 16.0 ANALOG-TO-DIGITAL CONVERTER (A/D) MODULE 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 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 ADCON0 register, shown in Figure 16-1, controls the operation of the A/D module. The ADCON1 register, shown in Figure 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. FIGURE 16-1: ADCON0 REGISTER (ADDRESS: 14h, BANK 5) R/W-0 CHS3 bit7 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 bit0 R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR reset 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) bit 3: bit 2: 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: Unimplemented: Read as '0' bit 0: ADON: A/D On bit 1 = A/D converter module is operating 0 = A/D converter module is shutoff and consumes no operating current 1998 Microchip Technology Inc. DS30289A-page 177 PIC17C7XX FIGURE 16-2: ADCON1 REGISTER (ADDRESS 15h, BANK 5) R/W-0 R/W-0 ADCS1 ADCS0 bit7 R/W-0 ADFM U-0 — R/W-0 PCFG3 R/W-0 PCFG2 R/W-0 PCFG1 R/W-0 PCFG0 bit0 R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR reset 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) bit 5: 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’. bit 4: Unimplemented: Read as '0' bit 3-1: PCFG3:PCFG1: A/D Port Configuration Control bits PCFG3:PCFG 1 AN15 AN14 AN13 AN12 AN11 AN10 AN9 AN8 AN7 AN6 AN5 AN4 AN3 AN2 AN1 AN0 000 001 A D A A A A A A A A A A A A A A A D A A A A A A A A A A A A A A 010 011 D D D D A D A A A A A A A A A A D D D D A D A A A A A A A A A A 100 101 110 D D D D D D D D D D D D A D D A A D A A A A A A D D D D D D D D D D D D A D D A A D A A A A A A 111 D D D D D D D D D D D D D D D D D = Digital I/O A = Analog input bit 0: 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. DS30289A-page 178 1998 Microchip Technology Inc. PIC17C7XX 2. The ADRESH:ADRESL registers contains 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 16-3. 3. 4. 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. 5. Configure A/D interrupt (if desired): • Clear ADIF bit • Set ADIE bit • Clear GLINTD bit Wait the required acquisition time. Start conversion: • Set GO/DONE bit (ADCON0) Wait for A/D conversion to complete, by either: • Polling for the GO/DONE bit to be cleared OR 6. Configure the A/D module: • Configure analog pins / voltage reference / and digital I/O (ADCON1) • Select A/D input channel (ADCON0) • Select A/D conversion clock (ADCON0) • Turn on A/D module (ADCON0) 7. • 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. FIGURE 16-3: A/D BLOCK DIAGRAM CHS3:CHS0 1011 1011 1011 1011 AN15(1) AN14(1) AN13(1) AN12(1) 1011 AN11 1010 AN10 1001 AN9 1000 AN8 0111 AN7 0110 AN6 0101 AN5 VIN 0100 (Input voltage) 0011 A/D Converter AN4 AN3 0010 AN2 0001 AN1 PCFG0 0000 AN0 VREF(Reference voltage) AVSS VREF+ AVDD (1) These channels only available on PIC16C76X devices 1998 Microchip Technology Inc. DS30289A-page 179 PIC17C7XX Figure 16-4 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 16-4: 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 DS30289A-page 180 1998 Microchip Technology Inc. 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 16-5. 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 16-5. The maximum recommended impedance for analog sources is 10 kΩ. 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 calculation is based on the following application system assumptions. CHOLD Rs Conversion Error VDD graph in Figure 16-5) Temperature VHOLD = = ≤ = 120 pF 10 kΩ 1/2 LSb 5V → Rss = 7 kΩ = = 50°C (system max.) 0V @ time = 0 (see EQUATION 16-1: ACQUISITION TIME TACQ = 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 kΩ + RSS + RS) ln(1/2047) EXAMPLE 16-1: CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME TACQ = TAMP + TC + TCOFF Temperature coefficient is only required for temperatures > 25°C. TACQ = 2 µs + Tc + [(Temp - 25°C)(0.05 µs/°C)] TC = -CHOLD (RIC + RSS + RS) ln(1/2047) -120 pF (1 kΩ + 7 kΩ + 10 kΩ) ln(0.0004885) -120 pF (18 kΩ) ln(0.0004885) -2.16 µs (-7.6241) 16.47 µs TACQ = 2 µs + 16.47 µs + [(50°C - 25°C)(0.05 µs/°C)] 18.447 µs + 1.25 µs 19.72 µs Note 1: The reference voltage (VREF) has no effect on the equation, since it cancels itself out. Note 2: The charge holding capacitor (CHOLD) is not discharged after each conversion. Note 3: The maximum recommended impedance for analog sources is 10 kΩ. This is required to meet the pin leakage specification. Note 4: After a conversion has completed, a 2.0TAD delay must complete before acquisition can begin again. During this time the holding capacitor is not connected to the selected A/D input channel. 1998 Microchip Technology Inc. DS30289A-page 181 PIC17C7XX FIGURE 16-5: ANALOG INPUT MODEL VDD Rs ANx CPIN 5 pF VA Sampling Switch VT = 0.6V VT = 0.6V RIC ≤ 1k SS RSS CHOLD = DAC capacitance = 120 pF I leakage ± 500 nA VSS Legend CPIN = input capacitance = threshold voltage VT I leakage = leakage current at the pin due to various junctions RIC SS CHOLD DS30289A-page 182 = interconnect resistance = sampling switch = sample/hold capacitance (from DAC) 6V 5V VDD 4V 3V 2V 5 6 7 8 9 10 11 Sampling Switch ( kΩ ) 1998 Microchip Technology Inc. PIC17C7XX 16.2 Selecting the A/D Conversion Clock 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: For correct A/D conversions, the A/D conversion clock (TAD) must be selected to ensure a minimum TAD time of 1.6 µs. 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. TAD vs. DEVICE OPERATING FREQUENCIES (STANDARD DEVICES (C)) AD Clock Source (TAD) Operation Device Frequency ADCS1:ADCS0 33 MHz 20 MHz 5 MHz 1.25 MHz 8TOSC 00 242 ns(2) 1.6 µs 6.4 µs 24 µs 32TOSC 01 6.4 µs 25.6 µs(3) 96 µs(3) 64TOSC 10 970 ns(2) 1.94 µs 400 ns(2) 1.6 µs 3.2 µs 12.8 µs(3) 51.2 µs(3) 192 µs(3) RC 2-6 2-6 2-6 2 - 6 µs(1) 2 - 6 µs Shaded cells are are outside of recommended ranges. The RC source has a typical TAD time of 4 µs. These values violate the minimum required TAD time. For faster conversion times, the selection of another clock source is recommended. When the device frequencies is greater than 1 MHz, the RC A/D conversion clock source is only recommended for sleep operation. 11 Legend: Note 1: 2: 3: 4: TABLE 16-2: (1, 4) µs(1, 4) ADCS1:ADCS0 Device Frequency 8 MHz µs(2) 4 MHz µs(2) 8TOSC 00 32TOSC 01 1.0 4.0 µs 2.0 8 µs 10 8.0 µs 16 µs 64TOSC RC Legend: Note 1: 2: 3: 4: µs(1, 4) TAD vs. DEVICE OPERATING FREQUENCIES (EXTENDED VOLTAGE DEVICES (LC)) AD Clock Source (TAD) Operation µs(1, 4) 333.33 kHz 1 MHz 333.33 kHz 4 µs 8 µs 24 µs 16 µs 32 µs(3) 1998 Microchip Technology Inc. µs(1, 4) 32 µs(3) 96 µs(3) 64 µs(3) 192 µs(3) 3-9 3-9 3-9 3 - 9 µs(1) 3 - 9 µs Shaded cells are are outside of recommended ranges. The RC source has a typical TAD time of 6 µs. These values violate the minimum required TAD time. For faster conversion times, the selection of another clock source is recommended. When the device frequencies is greater than 1 MHz, the RC A/D conversion clock source is only recommended for sleep operation. 11 (1, 4) µs(1, 4) 2 MHz µs(1) DS30289A-page 183 PIC17C7XX 16.3 Configuring Analog Port Pins 16.4 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. Note 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. A/D Conversions 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 16-6, after the GO bit is set, the first time segmant has a minimum of TCY and a maximum of TAD. EXAMPLE 16-2: A/D CONVERSION MOVLB CLRF MOVLW MOVWF MOVLB BCF BSF BSF BCF ; ; ; ; 5 ADCON1, F 0x01 ADCON0 4 PIR2, ADIF PIE2, ADIE INTSTA, PEIE CPUSTA, GLINTD ; ; ; ; ; ; ; ; ; 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 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 16-6: A/D CONVERSION TAD CYCLES Tcy to TAD TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7 TAD8 TAD9 TAD10 TAD11 b3 b1 b2 b0 b4 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. DS30289A-page 184 1998 Microchip Technology Inc. PIC17C7XX FIGURE 16-7: FLOWCHART OF A/D OPERATION ADON = 0 Yes ADON = 0? No Acquire Selected Channel Yes GO = 0? No A/D Clock = RC? Yes Start of A/D Conversion Delayed 1 Instruction Cycle Finish Conversion GO = 0, ADIF = 1 No No Device in SLEEP? Yes SLEEP Instruction? Yes Abort Conversion GO = 0, ADIF = 0 Finish Conversion GO = 0, ADIF = 1 Wait 2TAD No No Finish Conversion GO = 0, ADIF = 1 Wake-up Yes From Sleep? SLEEP Power-down A/D Wait 2TAD Stay in Sleep Power-down A/D Wait 2TAD 1998 Microchip Technology Inc. DS30289A-page 185 PIC17C7XX 16.4.1 16.5 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 16-8 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 8-bit registers. 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 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: 16.6 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. 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 16-8: A/D RESULT JUSTIFICATION 10-Bit Result ADFM = 0 ADFM = 1 0 2107 7 0000 00 ADRESH RESULT ADRESL 10-bits Right Justified DS30289A-page 186 7 0765 RESULT ADRESH 0 0000 00 ADRESL 10-bits Left Justified 1998 Microchip Technology Inc. PIC17C7XX Differential non-linearity measures the maximum actual code width versus the ideal code width. This measure is unadjusted. FIGURE 16-9: A/D TRANSFER FUNCTION 3FFh FEh 003h 002h 1023 LSb 3 LSb 1022 LSb 000h 1023.5 LSb 001h 1022.5 LSb 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. 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 16-9). 2 LSb 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. 16.9 2.5 LSb 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. An external RC filter is sometimes added for anti-aliasing of the input signal. The R component should be selected to ensure that the total source impedance is kept under the 10 kΩ 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. 1 LSb 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. 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. 1.5 LSb 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. 16.8 0.5 LSb 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. Digital code output3 16.7 Analog input voltage 16.10 References A good reference for the undestanding A/D converter is the "Analog-Digital Conversion Handbook" third edition, published by Prentice Hall (ISBN 0-13-03-2848-0). The maximum pin leakage current is specified in the Device Data Sheet electrical specification 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. 1998 Microchip Technology Inc. DS30289A-page 187 PIC17C7XX TABLE 16-3: Address REGISTERS/BITS ASSOCIATED WITH A/D Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 POR, BOR MCLR, WDT --11 qq11 06h, unbanked CPUSTA — — STAKAV GLINTD TO PD POR BOR --11 1100 07h, unbanked INTSTA PEIF T0CKIF T0IF INTF PEIE T0CKIE T0IE INTE 0000 0000 0000 0000 SSPIF BCLIF ADIF — CA4IF CA3IF TX2IF RC2IF 000- 0010 000- 0010 SSPIE BCLIE ADIE — CA4IE CA3IE TX2IE RC2IE 000- 0000 000- 0000 1111 1111 1111 1111 0000 0000 10h, Bank 4 PIR2 11h, Bank 4 PIE2 10h, Bank 5 DDRF 11h, Bank 5 PORTF 12h, Bank 5 DDRG Data Direction register for PORTG 13h, Bank 5 PORTG RG7/ RG6/ TX2/CK2 RX2/DT2 14h, Bank 5 ADCON0 CHS3 15h, Bank 5 ADCON1 ADCS1 16h, Bank 5 ADRESL 17h, Bank 5 ADRESH Legend: Note 1: Data Direction register for PORTF RF4/ AN8 RF3/ AN7 RF2/ AN6 RF1/ AN5 RF0/ AN4 0000 0000 1111 1111 1111 1111 RG5/ PWM3 RG4/ CAP3 RG3/ AN0/VREF + RG2/ AN1/VREF - RG1/ AN2 RG0/ AN3 xxxx 0000 uuuu 0000 CHS2 CHS1 CHS0 — GO/DONE — ADON 0000 -0-0 0000 -0-0 ADCS0 ADFM — PCFG3 PCFG2 PCFG1 PCFG0 000- 0000 000- 0000 A/D Result Low Register xxxx xxxx uuuu uuuu A/D Result High Register xxxx xxxx uuuu uuuu RF7/ AN11 RF6/ AN10 RF5/ AN9 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. DS30289A-page 188 1998 Microchip Technology Inc. PIC17C7XX 17.0 SPECIAL FEATURES OF THE CPU The PIC17CXXX has a Watchdog Timer which can be shutoff 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. What sets a microcontroller apart from other processors are special circuits to deal with the needs of real-time 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 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. FIGURE 17-1: CONFIGURATION WORDS U-x — R/P - 1 R/P - 1 U - x PM2 BODEN — bit 8 bit 7 — U-x — bit 8 bit 7 bit15 U-x bit15 bit 6H R/P - 1 PM1 U-x — U-x — U-x — U-x — U - x R/P - 1 R/P - 1 R/P - 1 R/P - 1 — PM0 WDTPS1 WDTPS0 FOSC1 U - x High (H) Table Read Addr. — FE0Fh - FE08h bit 0 R/P - 1 Low (L) Table Read Addr. FOSC0 FE07h - FE00h bit 0 BODEN: Brown-out Detect Enable 1= Brown-out Detect circuitry is enabled 0= Brown-out Detect circuitry is disabled bits 7H:6L:4L PM2, PM1, PM0, Processor Mode Select bits 111 = Microprocessor Mode 110 = Microcontroller mode 101 = Extended microcontroller mode 000 = Code protected microcontroller mode bits 2L:3L 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 bits 1L:0L FOSC1:FOSC0, Oscillator Select bits 11 = EC oscillator 10 = XT oscillator 01 = RC oscillator 00 = LF oscillator — Reserved 1998 Microchip Technology Inc. DS30289A-page 189 PIC17C7XX 17.1 Configuration Bits 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 is 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. 17.2 Oscillator Configurations 17.2.1 OSCILLATOR TYPES 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. 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. TABLE 17-1: Note: CONFIGURATION LOCATIONS Bit Address FOSC0 FOSC1 WDTPS0 WDTPS1 PM0 PM1 BODEN PM2 FE00h FE01h FE02h FE03h FE04h FE06h FE0Eh FE0Fh When programming the desired configuration locations, they must be programmed in ascending order. Starting with address FE00h. DS30289A-page 190 1998 Microchip Technology Inc. PIC17C7XX 17.3 Watchdog Timer (WDT) 17.3.2 The WDT and postscaler are cleared when: The Watchdog Timer’s function is to recover from software malfunction. 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 have 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). • • • • 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. 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. 17.3.1 CLEARING THE WDT AND POSTSCALER The WDT and postscaler become the Power-up Timer whenever the PWRT is invoked. 17.3.4 WDT PERIOD 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. 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. FIGURE 17-2: WATCHDOG TIMER BLOCK DIAGRAM On-chip RC Oscillator(1) WDT Postscaler WDTPS1:WDTPS0 4 - to - 1 MUX WDT Enable Note 1: This oscillator is separate from the external RC oscillator on the OSC1 pin. TABLE 17-2: Address — Legend: Note 1: REGISTERS/BITS ASSOCIATED WITH THE WATCHDOG TIMER Name Config 06h, Unbanked WDT Overflow CPUSTA Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on POR, BOR (Note 1) (Note 1) POR BOR --11 11qq --11 qquu See Figure 17-1 for location of WDTPSx bits in Configuration Word. — — STKAV GLINTD TO PD MCLR, WDT - = unimplemented read as '0', q - value depends on condition, shaded cells are not used by the WDT. This value will be as the device was programmed, or if unprogrammed, will read as all '1's. 1998 Microchip Technology Inc. DS30289A-page 191 PIC17C7XX 17.4 Power-down Mode (SLEEP) 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 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 wake-up). 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). 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. 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. 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 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. 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 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. Other peripherals cannot generate interrupts since during SLEEP, no on-chip Q clocks are present. FIGURE 17-3: WAKE-UP FROM SLEEP THROUGH INTERRUPT Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 Tost(2) CLKOUT(4) INT (RA0/INT pin) INTF flag '0' or '1' Interrupt Latency (2) GLINTD bit Processor in SLEEP INSTRUCTION FLOW PC PC Instruction fetched Instruction executed Inst (PC) = SLEEP Inst (PC-1) PC+1 PC+2 0004h Inst (PC+1) Inst (PC+2) SLEEP Inst (PC+1) 0005h 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. DS30289A-page 192 1998 Microchip Technology Inc. PIC17C7XX 17.4.2 MINIMIZING CURRENT CONSUMPTION 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. 17.5 Code Protection 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. 1998 Microchip Technology Inc. DS30289A-page 193 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 17-4: TYPICAL IN-CIRCUIT SERIAL PROGRAMMING CONNECTION External Connector Signals To Normal Connections PIC17C7XX +5V VDD 0V VSS VPP MCLR/VPP TEST CNTL TEST RA1/T0CKI Dev. CLK Data I/O RA4/RX1/DT1 Data CLK RA5/TX1/CK1 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. VDD To Normal Connections The device clock source starts. Wait 80 device clocks for Boot ROM code to configure the USART/SCI. Commands may now be sent. TABLE 17-3: ICSP INTERFACE PINS Name RA4/RX1/DT1 RA5/TX1/CK1 RA1/T0CKI TEST MCLR/VPP VDD VSS DS30289A-page 194 Function DT CK OSCI TEST MCLR/VPP VDD VSS Type I/O I I I P P P During Programming 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 1998 Microchip Technology Inc. PIC17C7XX 18.0 INSTRUCTION SET SUMMARY 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. 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. TABLE 18-1: OPCODE FIELD DESCRIPTIONS Field Description f Register file address (00h to FFh) p Peripheral register file address (00h to 1Fh) i Table pointer control i = '0' (do not change) i = '1' (increment after instruction execution) t Table byte select t = '0' (perform operation on lower byte) t = '1' (perform operation on upper byte literal field, constant data) WREG Working register (accumulator) b Bit address within an 8-bit file register k Literal field, constant data or label x Don't care location (= '0' or '1') The assembler will generate code with x = '0'. It is the recommended form of use for compatibility with all Microchip software tools. d Destination select 0 = store result in WREG 1 = store result in file register f Default is d = '1' u Unused, encoded as '0' s Destination select 0 = store result in file register f and in the WREG 1 = store result in file register f Default is s = '1' 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. label Label name literal and control operations, 'k' represents an 8- or 13-bit constant or literal value. GLINTD Global Interrupt Disable bit (CPUSTA<4>) The instruction set is highly orthogonal and is grouped into: TBLAT Table Latch (16-bit) consists of high byte (TBLATH) and low byte (TBLATL) • byte-oriented operations • bit-oriented operations • literal and control operations TBLATL Table Latch low byte 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. C,DC, ALU status bits Carry, Digit Carry, Zero, Overflow Z,OV TBLPTR Table Pointer (16-bit) TBLATH Table Latch high byte TOS Top of Stack PC Program Counter BSR Bank Select Register WDT Watchdog Timer Counter TO Time-out bit PD Power-down bit dest 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) 1998 Microchip Technology Inc. DS30289A-page 195 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 To represent a binary number: 0000 0100b where b signifies a binary string. FIGURE 18-1: GENERAL FORMAT FOR INSTRUCTIONS Byte-oriented file register operations 9 8 d OPCODE 7 0 f (FILE #) d = 0 for destination WREG d = 1 for destination f f = 8-bit file register address 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 18.1.2 PCH → PCLATH; PCL → dest Write PCL: PCLATH → PCH; 8-bit destination value → PCL Read-Modify-Write: PCL→ ALU operand PCLATH → PCH; 8-bit result → PCL 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-oriented file register operations OPCODE 11 10 8 7 b (BIT #) 0 f (FILE #) b = 3-bit address f = 8-bit file register address Literal and control operations 15 8 OPCODE 0 k (literal) k = 8-bit immediate value BIT MANIPULATION 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: 7 PCL AS SOURCE OR DESTINATION Read PC: 0 f (FILE #) p = peripheral register file address f = 8-bit file register address 15 ALUSTA AS DESTINATION Read, write or read-modify-write on PCL may have the following results: Byte to Byte move operations 15 13 12 8 7 OPCODE p (FILE #) Special Function Registers as Source/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. where h signifies a hexadecimal digit. 15 18.1 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 CALL and GOTO operations 15 13 12 OPCODE 0 k (literal) k = 13-bit immediate value DS30289A-page 196 1998 Microchip Technology Inc. PIC17C7XX 18.2 Q Cycle Activity The four Q cycles that make up an instruction cycle (TCY) can be generalized as: 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. 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 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Tosc TCY1 1998 Microchip Technology Inc. TCY2 TCY3 DS30289A-page 197 PIC17C7XX TABLE 18-2: PIC17CXXX INSTRUCTION SET Mnemonic, Operands Description Cycles 16-bit Opcode MSb LSb Status Affected Notes BYTE-ORIENTED FILE REGISTER OPERATIONS ADDWF f,d ADD WREG to f 1 0000 111d ffff ffff OV,C,DC,Z ADDWFC f,d ADD WREG and Carry bit to f 1 0001 000d ffff ffff OV,C,DC,Z ANDWF f,d AND WREG with f 1 0000 101d ffff ffff Z CLRF f,s Clear f, or Clear f and Clear WREG 1 0010 100s ffff ffff None COMF f,d Complement f 1 0001 001d ffff ffff Z CPFSEQ f Compare f with WREG, skip if f = WREG 1 (2) 0011 0001 ffff ffff None 6,8 CPFSGT f Compare f with WREG, skip if f > WREG 1 (2) 0011 0010 ffff ffff None 2,6,8 CPFSLT f Compare f with WREG, skip if f < WREG 1 (2) 0011 0000 ffff ffff None 2,6,8 DAW f,s Decimal Adjust WREG Register 1 0010 111s ffff ffff C DECF f,d Decrement f 1 0000 011d ffff ffff OV,C,DC,Z DECFSZ f,d Decrement f, skip if 0 1 (2) 0001 011d ffff ffff None 6,8 DCFSNZ f,d Decrement f, skip if not 0 1 (2) 0010 011d ffff ffff None 6,8 INCF f,d Increment f 1 0001 010d ffff ffff OV,C,DC,Z INCFSZ f,d Increment f, skip if 0 1 (2) 0001 111d ffff ffff None 6,8 INFSNZ f,d Increment f, skip if not 0 1 (2) 0010 010d ffff ffff None 6,8 IORWF f,d Inclusive OR WREG with f 1 0000 100d ffff ffff Z MOVFP f,p Move f to p 1 011p pppp ffff ffff None MOVPF p,f Move p to f 1 010p pppp ffff ffff Z MOVWF f Move WREG to f 1 0000 0001 ffff ffff None MULWF f Multiply WREG with f 1 0011 0100 ffff ffff None NEGW f,s Negate WREG 1 0010 110s ffff ffff OV,C,DC,Z NOP — No Operation 1 0000 0000 0000 0000 None RLCF f,d Rotate left f through Carry 1 0001 101d ffff ffff C RLNCF f,d Rotate left f (no carry) 1 0010 001d ffff ffff None RRCF f,d Rotate right f through Carry 1 0001 100d ffff ffff C RRNCF f,d Rotate right f (no carry) 1 0010 000d ffff ffff None SETF f,s Set f 1 0010 101s ffff ffff None 3 SUBWF f,d Subtract WREG from f 1 0000 010d ffff ffff OV,C,DC,Z 1 SUBWFB f,d Subtract WREG from f with Borrow 1 0000 001d ffff ffff OV,C,DC,Z 1 SWAPF f,d Swap f 1 0001 110d ffff ffff None TABLRD t,i,f Table Read 2 (3) 1010 10ti ffff ffff None 7 TABLWT t,i,f Table Write 2 1010 11ti ffff ffff None 5 TLRD t,f Table Latch Read 1 1010 00tx ffff ffff None t,f Table Latch Write 1 1010 01tx ffff ffff None TLWT Legend: Note 1: 2: 3: 4: 5: 6: 7: 8: 3 3 1,3 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 an NOP is executed. DS30289A-page 198 1998 Microchip Technology Inc. PIC17C7XX TABLE 18-2: Mnemonic, Operands PIC17CXXX INSTRUCTION SET (Cont.’d) Description Cycles 16-bit Opcode MSb TSTFSZ f Test f, skip if 0 XORWF f,d Exclusive OR WREG with f LSb Status Affected Notes 1 (2) 0011 0011 ffff ffff None 1 0000 110d ffff ffff Z 6,8 BIT-ORIENTED FILE REGISTER OPERATIONS BCF f,b Bit Clear f 1 1000 1bbb ffff ffff None BSF f,b Bit Set f 1 1000 0bbb ffff ffff None BTFSC f,b Bit test, skip if clear 1 (2) 1001 1bbb ffff ffff None 6,8 BTFSS f,b Bit test, skip if set 1 (2) 1001 0bbb ffff ffff None 6,8 BTG f,b Bit Toggle f 1 0011 1bbb ffff ffff None OV,C,DC,Z LITERAL AND CONTROL OPERATIONS ADDLW k ADD literal to WREG 1 1011 0001 kkkk kkkk ANDLW k AND literal with WREG 1 1011 0101 kkkk kkkk Z CALL k Subroutine Call 2 111k kkkk kkkk kkkk None CLRWDT — Clear Watchdog Timer 1 0000 0000 0000 0100 TO,PD GOTO k Unconditional Branch 2 110k kkkk kkkk kkkk None IORLW k Inclusive OR literal with WREG 1 1011 0011 kkkk kkkk Z LCALL k Long Call 2 1011 0111 kkkk kkkk None MOVLB k Move literal to low nibble in BSR 1 1011 1000 uuuu kkkk None MOVLR k Move literal to high nibble in BSR 1 1011 101x kkkk uuuu None MOVLW k Move literal to WREG 1 1011 0000 kkkk kkkk None MULLW k Multiply literal with WREG 1 1011 1100 kkkk kkkk None RETFIE — Return from interrupt (and enable interrupts) 2 0000 0000 0000 0101 GLINTD 7 RETLW k Return literal to WREG 2 1011 0110 kkkk kkkk None 7 RETURN — Return from subroutine 2 0000 0000 0000 0010 None 7 SLEEP — Enter SLEEP Mode 1 0000 0000 0000 0011 TO, PD SUBLW k Subtract WREG from literal 1 1011 0010 kkkk kkkk OV,C,DC,Z XORLW k Exclusive OR literal with WREG 1 1011 0100 kkkk kkkk Z Legend: Note 1: 2: 3: 4: 5: 6: 7: 8: 7 7 4,7 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 an NOP is executed. 1998 Microchip Technology Inc. DS30289A-page 199 PIC17C7XX ADDLW ADD Literal to WREG ADDWF ADD WREG to f Syntax: [ label ] ADDLW Syntax: [ label ] ADDWF Operands: 0 ≤ k ≤ 255 Operands: Operation: (WREG) + k → (WREG) 0 ≤ f ≤ 255 d ∈ [0,1] Status Affected: OV, C, DC, Z Operation: (WREG) + (f) → (dest) Status Affected: OV, C, DC, Z Encoding: Description: 1011 1 Cycles: 1 Q Cycle Activity: Q1 Example: kkkk kkkk The contents of WREG are added to the 8-bit literal 'k' and the result is placed in WREG. Words: Decode 0001 k Q2 Q3 Q4 Read literal 'k' Process Data Write to WREG ADDLW Before Instruction WREG = 0x10 After Instruction WREG = 0x25 Encoding: 0000 111d f,d ffff ffff Description: 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: 1 Cycles: 1 Q Cycle Activity: Q1 Decode 0x15 Q2 Q3 Q4 Read register 'f' Process Data Write to destination Example: ADDWF REG, 0 Before Instruction WREG REG = = 0x17 0xC2 After Instruction WREG REG DS30289A-page 200 = = 0xD9 0xC2 1998 Microchip Technology Inc. PIC17C7XX ADDWFC ADD WREG and Carry bit to f ANDLW And Literal with WREG Syntax: [ label ] ADDWFC Syntax: [ label ] ANDLW Operands: 0 ≤ f ≤ 255 d ∈ [0,1] Operands: 0 ≤ k ≤ 255 Operation: (WREG) + (f) + C → (dest) (WREG) .AND. (k) → (WREG) Operation: Status Affected: Z Status Affected: OV, C, DC, Z Encoding: Encoding: 0001 Description: f,d 000d ffff ffff 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'. Words: 1 Cycles: Decode Q2 Q3 Q4 Process Data Write to destination Example: ADDWFC Before Instruction Carry bit = REG = WREG = 1 0x02 0x4D REG 0 kkkk kkkk Description: Words: 1 Cycles: 1 Decode Read register 'f' 0101 The contents of WREG are AND’ed with the 8-bit literal 'k'. The result is placed in WREG. Q Cycle Activity: Q1 1 Q Cycle Activity: Q1 1011 k Q2 Q3 Q4 Read literal 'k' Process Data Write to WREG Example: ANDLW 0x5F Before Instruction WREG = 0xA3 After Instruction WREG = 0x03 After Instruction Carry bit = REG = WREG = 0 0x02 0x50 1998 Microchip Technology Inc. DS30289A-page 201 PIC17C7XX ANDWF AND WREG with f Syntax: [ label ] ANDWF BCF Bit Clear f Syntax: Operands: [ label ] BCF 0 ≤ f ≤ 255 d ∈ [0,1] Operands: 0 ≤ f ≤ 255 0≤b≤7 Operation: (WREG) .AND. (f) → (dest) Operation: 0 → (f<b>) Status Affected: Z Status Affected: None Encoding: 0000 Description: 101d f,d ffff ffff Encoding: 1000 f,b 1bbb ffff ffff 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'. Description: Bit 'b' in register 'f' is cleared. Words: 1 Cycles: 1 Words: 1 Cycles: 1 Q Cycle Activity: Q1 Decode Q Cycle Activity: Q1 Decode Q2 Q3 Q4 Read register 'f' Process Data Write to destination Example: Q2 Q3 Q4 Read register 'f' Process Data Write register 'f' BCF FLAG_REG, 7 Before Instruction Example: ANDWF = = FLAG_REG = 0xC7 After Instruction Before Instruction WREG REG REG, 1 0x17 0xC2 FLAG_REG = 0x47 After Instruction WREG REG = = DS30289A-page 202 0x17 0x02 1998 Microchip Technology Inc. PIC17C7XX BSF Bit Set f Syntax: [ label ] BSF BTFSC Bit Test, skip if Clear Syntax: Operands: [ label ] BTFSC f,b 0 ≤ f ≤ 255 0≤b≤7 Operands: 0 ≤ f ≤ 255 0≤b≤7 Operation: 1 → (f<b>) Operation: skip if (f<b>) = 0 Status Affected: None Status Affected: None Encoding: 1000 f,b 0bbb ffff Description: Bit 'b' in register 'f' is set. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Decode Example: ffff Q2 Q3 Q4 Read register 'f' Process Data Write register 'f' BSF FLAG_REG, 7 Before Instruction Encoding: FLAG_REG= 0x8A 1bbb ffff ffff 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. Words: 1 Cycles: 1(2) Q Cycle Activity: Q1 FLAG_REG= 0x0A After Instruction 1001 Description: Q2 Q3 Q4 Decode Read register 'f' Process Data No operation Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip: 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 1998 Microchip Technology Inc. DS30289A-page 203 PIC17C7XX BTFSS Bit Test, skip if Set BTG Bit Toggle f Syntax: [ label ] BTFSS f,b Syntax: [ label ] BTG f,b Operands: 0 ≤ f ≤ 127 0≤b<7 Operands: 0 ≤ f ≤ 255 0≤b<7 Operation: skip if (f<b>) = 1 Operation: (f<b>) → (f<b>) Status Affected: None Status Affected: None Encoding: Description: 1001 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 an NOP is executed instead, making this a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: Q1 Decode 0bbb Encoding: Q3 Read register 'f' Process Data Q4 No operation If skip: 1bbb ffff ffff Bit 'b' in data memory location 'f' is inverted. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Decode Q2 0011 Description: Q2 Q3 Q4 Read register 'f' Process Data Write register 'f' Example: BTG PORTC, 4 Before Instruction: PORTC = 0111 0101 [0x75] After Instruction: Q1 Q2 Q3 Q4 No operation No operation No operation No operation Example: HERE FALSE TRUE BTFSS : : PORTC = 0110 0101 [0x65] FLAG,1 Before Instruction PC = address (HERE) = = = = 0; address (FALSE) 1; address (TRUE) After Instruction If FLAG<1> PC If FLAG<1> PC DS30289A-page 204 1998 Microchip Technology Inc. PIC17C7XX CALL Subroutine Call CLRF Syntax: [ label ] CALL k Syntax: [label] CLRF Operands: 0 ≤ k ≤ 8191 Operands: 0 ≤ f ≤ 255 Operation: PC+ 1→ TOS, k → PC<12:0>, k<12:8> → PCLATH<4:0>; PC<15:13> → PCLATH<7:5> Operation: 00h → f, s ∈ [0,1] 00h → dest Status Affected: None Status Affected: None Encoding: Encoding: Description: 111k 1 Cycles: 2 Q Cycle Activity: Q1 No operation Example: kkkk Q2 Q3 Q4 Read literal 'k'<7:0>, Push PC to stack No operation Process Data Write to PC HERE CALL THERE No operation 100s ffff ffff 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: 1 Cycles: 1 Q Cycle Activity: Q1 Example: No operation 0010 f,s Description: Decode Before Instruction PC = kkkk 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 upper-eight bits of the PC are copied into PCLATH. CALL is a two-cycle instruction. See LCALL for calls outside 8K memory space. Words: Decode kkkk Clear f Q2 Q3 Q4 Read register 'f' Process Data Write register 'f' and if specified WREG CLRF FLAG_REG, 1 Before Instruction FLAG_REG WREG = = 0x5A 0x01 = = 0x00 0x01 After Instruction FLAG_REG WREG Address(HERE) After Instruction PC = TOS = Address(THERE) Address (HERE + 1) 1998 Microchip Technology Inc. DS30289A-page 205 PIC17C7XX CLRWDT Clear Watchdog Timer COMF Complement f Syntax: [ label ] CLRWDT Syntax: [ label ] COMF Operands: None Operands: Operation: 00h → WDT 0 → WDT postscaler, 1 → TO 1 → PD 0 ≤ f ≤ 255 d ∈ [0,1] Status Affected: Description: 0000 1 Cycles: 1 Q Cycle Activity: Q1 Example: 0100 0001 Q2 Q3 Q4 No operation Process Data No operation WDT counter WDT Postscaler ffff ffff 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: 1 Cycles: 1 Q2 Q3 Q4 Read register 'f' Process Data Write to destination Example: COMF REG1,0 Before Instruction CLRWDT WDT counter 001d Description: Decode REG1 = ? = = = = 0x00 0 1 1 After Instruction DS30289A-page 206 Z Q Cycle Activity: Q1 Before Instruction TO PD 0000 CLRWDT instruction resets the Watchdog Timer. It also resets the postscaler of the WDT. Status bits TO and PD are set. Words: Decode 0000 ( f ) → (dest) Status Affected: Encoding: TO, PD Encoding: Operation: f,d = 0x13 After Instruction REG1 WREG = = 0x13 0xEC 1998 Microchip Technology Inc. PIC17C7XX CPFSEQ Compare f with WREG, skip if f = WREG CPFSGT Compare f with WREG, skip if f > WREG Syntax: [ label ] CPFSEQ Syntax: [ label ] CPFSGT Operands: 0 ≤ f ≤ 255 Operands: 0 ≤ f ≤ 255 Operation: (f) – (WREG), skip if (f) = (WREG) (unsigned comparison) Operation: (f) − (WREG), skip if (f) > (WREG) (unsigned comparison) Status Affected: None Status Affected: None Encoding: Description: 0011 0001 f ffff ffff Compares the contents of data memory location 'f' to the contents of WREG by performing an unsigned subtraction. Encoding: Description: 1 Cycles: 1 (2) Q Cycle Activity: Q1 Q2 Q3 Q4 Read register 'f' Process Data No operation Q1 Q2 Q3 Q4 No operation No operation No operation No operation Decode If skip: Example: HERE NEQUAL EQUAL CPFSEQ REG : : Before Instruction PC Address WREG REG = = = HERE ? ? = = ≠ = WREG; Address (EQUAL) WREG; Address (NEQUAL) ffff ffff Words: 1 Cycles: 1 (2) Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data No operation Q1 Q2 Q3 Q4 No operation No operation No operation No operation HERE NGREATER GREATER CPFSGT REG : : If skip: Example: Before Instruction PC WREG = = Address (HERE) ? > = ≤ = WREG; Address (GREATER) WREG; Address (NGREATER) After Instruction After Instruction If REG PC If REG PC 0010 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 an NOP is executed instead making this a two-cycle instruction. If 'f' = WREG then the fetched instruction is discarded and an NOP is executed instead making this a two-cycle instruction. Words: 0011 f 1998 Microchip Technology Inc. If REG PC If REG PC DS30289A-page 207 PIC17C7XX CPFSLT Compare f with WREG, skip if f < WREG DAW Syntax: [ label ] CPFSLT Syntax: [label] DAW Operands: 0 ≤ f ≤ 255 Operands: Operation: (f) – (WREG), skip if (f) < (WREG) (unsigned comparison) 0 ≤ f ≤ 255 s ∈ [0,1] Operation: 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>; Status Affected: 0011 0000 ffff Words: 1 Cycles: 1 (2) Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data No operation Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip: HERE NLESS LESS CPFSLT REG : : f,s ffff 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> 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 an NOP is executed instead making this a two-cycle instruction. Example: Decimal Adjust WREG Register None Encoding: Description: f Status Affected: C Encoding: 0010 Description: 111s s = 1: Words: 1 Cycles: 1 Q Cycle Activity: Q1 Decode = = Address (HERE) ? < = ≥ = WREG; Address (LESS) WREG; Address (NLESS) Q2 Q3 Q4 Read register 'f' Process Data Write register 'f' and other specified register Example1: After Instruction If REG PC If REG PC ffff Result is placed in Data memory location 'f'. Before Instruction PC W ffff 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. DAW REG1, 0 Before Instruction WREG REG1 C DC = = = = 0xA5 ?? 0 0 After Instruction WREG REG1 C DC = = = = 0x05 0x05 1 0 Example 2: Before Instruction WREG REG1 C DC = = = = 0xCE ?? 0 0 After Instruction WREG REG1 C DC DS30289A-page 208 = = = = 0x24 0x24 1 0 1998 Microchip Technology Inc. PIC17C7XX DECF Decrement f DECFSZ Decrement f, skip if 0 Syntax: [ label ] DECF f,d Syntax: [ label ] DECFSZ f,d Operands: 0 ≤ f ≤ 255 d ∈ [0,1] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] Operation: (f) – 1 → (dest) Operation: Status Affected: OV, C, DC, Z (f) – 1 → (dest); skip if result = 0 Status Affected: None Encoding: 0000 Description: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Process Data Write to destination DECF CNT, Before Instruction = = = = 1 Encoding: 0001 Description: 011d ffff ffff 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 an NOP is executed instead making it a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Q1 Q2 Q3 Q4 No operation No operation No operation No operation HERE DECFSZ GOTO 0x01 0 After Instruction CNT Z ffff Read register 'f' Example: CNT Z 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: Decode 011d If skip: 0x00 1 Example: CNT, 1 HERE NZERO ZERO Before Instruction PC = Address (HERE) After Instruction CNT If CNT PC If CNT PC 1998 Microchip Technology Inc. = = = ≠ = CNT - 1 0; Address (HERE) 0; Address (NZERO) DS30289A-page 209 PIC17C7XX DCFSNZ Decrement f, skip if not 0 GOTO Unconditional Branch Syntax: [label] DCFSNZ f,d Syntax: [ label ] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] Operands: 0 ≤ k ≤ 8191 Operation: Operation: (f) – 1 → (dest); skip if not 0 k → PC<12:0>; k<12:8> → PCLATH<4:0>, PC<15:13> → PCLATH<7:5> Status Affected: None Status Affected: None Encoding: Description: 0010 011d ffff ffff Encoding: 110k GOTO k kkkk kkkk kkkk Description: If the result is not 0, the next instruction, which is already fetched, is discarded, and an NOP is executed instead making it a two-cycle instruction. 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. Words: 1 Words: 1 Cycles: 2 Cycles: 1(2) Q Cycle Activity: Q1 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'. Q Cycle Activity: Q1 Q2 Q3 Q4 Read register 'f' Process Data Write to destination Q1 Q2 Q3 Q4 No operation No operation No operation No operation Decode If skip: Q2 Q3 Q4 Decode Read literal 'k' Process Data Write to PC No operation No operation No operation No operation Example: PC = Example: HERE ZERO NZERO DCFSNZ : : GOTO THERE After Instruction Address (THERE) 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 DS30289A-page 210 1998 Microchip Technology Inc. PIC17C7XX INCF Increment f INCFSZ Increment f, skip if 0 Syntax: [ label ] Syntax: [ label ] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] Operation: (f) + 1 → (dest) Operation: Status Affected: OV, C, DC, Z (f) + 1 → (dest) skip if result = 0 Status Affected: None Encoding: 0001 Description: 010d 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: 1 Cycles: 1 Q Cycle Activity: Q1 Decode INCF f,d Q2 Q3 Q4 Read register 'f' Process Data Write to destination Example: INCF CNT, 1 Encoding: = = = 0xFF 0 ? After Instruction CNT Z C = = = 0x00 1 1 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'. If the result is 0, the next instruction, which is already fetched, is discarded, and an NOP is executed instead making it a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data Write to destination Q1 Q2 Q3 Q4 No operation No operation No operation No operation Before Instruction CNT Z C 0001 Description: INCFSZ f,d If skip: Example: HERE NZERO ZERO INCFSZ : : CNT, 1 Before Instruction PC = Address (HERE) After Instruction CNT If CNT PC If CNT PC 1998 Microchip Technology Inc. = = = ≠ = CNT + 1 0; Address(ZERO) 0; Address(NZERO) DS30289A-page 211 PIC17C7XX INFSNZ Increment f, skip if not 0 IORLW Inclusive OR Literal with WREG Syntax: [label] Syntax: [ label ] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] Operands: 0 ≤ k ≤ 255 Operation: (f) + 1 → (dest), skip if not 0 (WREG) .OR. (k) → (WREG) Operation: Status Affected: Z Status Affected: INFSNZ f,d Encoding: None Encoding: 0010 Description: 010d 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'. If the result is not 0, the next instruction, which is already fetched, is discarded, and an NOP is executed instead making it a two-cycle instruction. Words: 1 Cycles: 1(2) Q Cycle Activity: Q1 1011 IORLW k 0011 kkkk kkkk Description: The contents of WREG are OR’ed with the eight bit literal 'k'. The result is placed in WREG. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Decode Example: Q2 Q3 Q4 Read literal 'k' Process Data Write to WREG IORLW 0x35 Before Instruction Q2 Q3 Q4 WREG Read register 'f' Process Data Write to destination After Instruction Q1 Q2 Q3 Q4 No operation No operation No operation No operation Decode WREG = = 0x9A 0xBF If skip: Example: HERE ZERO NZERO INFSNZ REG, 1 Before Instruction REG = REG After Instruction REG If REG PC If REG PC = = = = = DS30289A-page 212 REG + 1 1; Address (ZERO) 0; Address (NZERO) 1998 Microchip Technology Inc. PIC17C7XX IORWF Inclusive OR WREG with f LCALL Long Call Syntax: [ label ] Syntax: [ label ] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] Operands: 0 ≤ k ≤ 255 Operation: Operation: (WREG) .OR. (f) → (dest) PC + 1 → TOS; k → PCL, (PCLATH) → PCH Status Affected: Z Status Affected: None Encoding: 0000 IORWF 100d f,d ffff ffff Description: 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: 1 Cycles: 1 Q Cycle Activity: Q1 Decode Q2 Q3 Q4 Read register 'f' Process Data Write to destination Example: IORWF RESULT, 0 Before Instruction RESULT = WREG = 0x13 0x91 Encoding: Description: 0x13 0x93 1011 0111 k kkkk kkkk LCALL allows an unconditional subroutine call to anywhere within the 64K program memory space. 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 is embedded in the instruction. The upper 8-bits of PC is loaded from PC high holding latch, PCLATH. Words: 1 Cycles: 2 Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read literal 'k' Process Data Write register PCL No operation No operation No operation No operation After Instruction RESULT = WREG = LCALL Example: MOVLW MOVPF LCALL HIGH(SUBROUTINE) WREG, PCLATH LOW(SUBROUTINE) Before Instruction SUBROUTINE = PC = 16-bit Address ? After Instruction PC 1998 Microchip Technology Inc. = Address (SUBROUTINE) DS30289A-page 213 PIC17C7XX MOVFP Move f to p MOVLB Move Literal to low nibble in BSR Syntax: [label] Syntax: [ label ] Operands: 0 ≤ f ≤ 255 0 ≤ p ≤ 31 Operands: 0 ≤ k ≤ 15 Operation: (f) → (p) k → (BSR<3:0>) Operation: Status Affected: None Status Affected: None Encoding: Encoding: Description: MOVFP f,p 011p pppp ffff ffff Words: 1 Cycles: 1 Decode Q2 Q3 Q4 Read register 'f' Process Data Write register 'p' MOVFP uuuu kkkk Words: 1 Cycles: 1 Q Cycle Activity: Q1 Decode Q2 Q3 Q4 Read literal 'k' Process Data Write literal 'k' to BSR<3:0> MOVLB 5 Before Instruction BSR register = 0x22 = 0x25 (Bank 5) After Instruction BSR register Example: 1000 Description: Example: Q Cycle Activity: Q1 1011 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. MOVLB k REG1, REG2 Before Instruction REG1 REG2 = = 0x33, 0x11 = = 0x33, 0x33 After Instruction REG1 REG2 DS30289A-page 214 1998 Microchip Technology Inc. PIC17C7XX Move Literal to high nibble in BSR MOVLW Move Literal to WREG MOVLR Syntax: [ label ] Syntax: [ label ] Operands: Operands: 0 ≤ k ≤ 15 0 ≤ k ≤ 255 Operation: k → (BSR<7:4>) k → (WREG) Operation: Status Affected: None Status Affected: None Encoding: Encoding: Description: 1011 1 Cycles: 1 kkkk uuuu 1011 0000 kkkk kkkk Description: Words: 1 Cycles: 1 Q Cycle Activity: Q1 Decode Q2 Q3 Q4 Read literal 'k' Process Data Write to WREG MOVLW Q2 Q3 Q4 After Instruction Read literal 'k' Process Data Write literal 'k' to BSR<7:4> WREG MOVLR MOVLW k The eight bit literal 'k' is loaded into WREG. Example: Q Cycle Activity: Q1 Example: 101x 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. Words: Decode MOVLR k = 0x5A 0x5A 5 Before Instruction BSR register = 0x22 = 0x52 After Instruction BSR register 1998 Microchip Technology Inc. DS30289A-page 215 PIC17C7XX MOVPF Move p to f MOVWF Move WREG to f Syntax: [label] Syntax: [ label ] Operands: 0 ≤ f ≤ 255 0 ≤ p ≤ 31 Operands: 0 ≤ f ≤ 255 Operation: (p) → (f) (WREG) → (f) Operation: Status Affected: None Status Affected: Z Encoding: Encoding: MOVPF p,f 010p Description: pppp 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. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Decode 0001 f ffff ffff Description: Move data from WREG to register 'f'. Location 'f' can be anywhere in the 256 byte data space. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Decode Q2 Q3 Q4 Read register 'f' Process Data Write register 'f' Example: MOVWF REG Before Instruction WREG REG Q2 Q3 Q4 Read register 'p' Process Data Write register 'f' Example: 0000 MOVWF MOVPF = = 0x4F 0xFF After Instruction WREG REG = = 0x4F 0x4F REG1, REG2 Before Instruction REG1 REG2 = = 0x11 0x33 = = 0x11 0x11 After Instruction REG1 REG2 DS30289A-page 216 1998 Microchip Technology Inc. PIC17C7XX MULLW Multiply Literal with WREG MULWF Multiply WREG with f Syntax: [ label ] Syntax: [ label ] Operands: 0 ≤ k ≤ 255 Operands: 0 ≤ f ≤ 255 Operation: (k x WREG) → PRODH:PRODL Operation: (WREG x f) → PRODH:PRODL Status Affected: None Status Affected: None Encoding: Description: MULLW 1011 1100 k kkkk kkkk 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. Encoding: Description: 0011 ffff 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. Note that neither overflow nor carry is possible in this operation. A zero result is possible but not detected. 1 Words: 1 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Read literal 'k' Process Data Write registers PRODH: PRODL MULLW 0xC4 Before Instruction WREG PRODH PRODL Q Cycle Activity: Q1 Decode Example: Q2 Q3 Q4 Read register 'f' Process Data Write registers PRODH: PRODL MULWF REG Before Instruction = = = 0xE2 ? ? WREG REG PRODH PRODL = = = 0xC4 0xAD 0x08 After Instruction After Instruction WREG PRODH PRODL ffff WREG is unchanged. None of the status flags are affected. Cycles: Example: 0100 f 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. Words: Decode MULWF 1998 Microchip Technology Inc. WREG REG PRODH PRODL = = = = 0xC4 0xB5 ? ? = = = = 0xC4 0xB5 0x8A 0x94 DS30289A-page 217 PIC17C7XX NEGW Negate W Syntax: [label] Operands: 0 ≤ f ≤ 255 s ∈ [0,1] Operation: WREG + 1 → (f); WREG + 1 → s Status Affected: NEGW f,s 0010 Description: 110s ffff ffff 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'. Words: 1 Cycles: 1 No Operation Syntax: [ label ] Operands: None Operation: No operation Status Affected: None Encoding: OV, C, DC, Z Encoding: NOP 0000 NOP 0000 Description: No operation. Words: 1 Cycles: 1 Q Cycle Activity: Q1 Decode 0000 0000 Q2 Q3 Q4 No operation No operation No operation Example: Q Cycle Activity: Q1 Decode Q2 Q3 Q4 Read register 'f' Process Data Write register 'f' and other specified register Example: NEGW None. REG,0 Before Instruction WREG REG = = 0011 1010 1010 1011 [0x3A], [0xAB] 1100 0110 1100 0110 [0xC6] [0xC6] After Instruction WREG REG = = DS30289A-page 218 1998 Microchip Technology Inc. PIC17C7XX RETFIE Return from Interrupt RETLW Return Literal to WREG Syntax: [ label ] Syntax: [ label ] Operands: None Operands: 0 ≤ k ≤ 255 Operation: TOS → (PC); 0 → GLINTD; PCLATH is unchanged. Operation: k → (WREG); TOS → (PC); PCLATH is unchanged Status Affected: None Status Affected: GLINTD Encoding: Encoding: 0000 RETFIE 0000 0000 0101 1011 Words: 1 Words: 1 Cycles: 2 Cycles: 2 Q Cycle Activity: Q1 Q3 Q4 Decode No operation Clear GLINTD POP PC from stack No operation No operation No operation No operation Example: kkkk Q2 Q3 Q4 Decode Read literal 'k' Process Data No operation No operation No operation POP PC from stack, Write to WREG No operation RETFIE Example: After Interrupt PC = GLINTD = kkkk 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. 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>). Q2 0110 Description: Description: Q Cycle Activity: Q1 RETLW k CALL TABLE ; ; ; ; : TABLE ADDWF PC ; RETLW k0 ; RETLW k1 ; : : RETLW kn ; TOS 0 WREG contains table offset value WREG now has table value WREG = offset Begin table End of table Before Instruction WREG = 0x07 After Instruction WREG 1998 Microchip Technology Inc. = value of k7 DS30289A-page 219 PIC17C7XX RETURN Return from Subroutine RLCF Rotate Left f through Carry Syntax: [ label ] Syntax: [ label ] RLCF Operands: None Operands: Operation: TOS → PC; 0 ≤ f ≤ 255 d ∈ [0,1] Status Affected: None Operation: f<n> → d<n+1>; f<7> → C; C → d<0> Return from subroutine. The stack is popped and the top of the stack (TOS) is loaded into the program counter. Status Affected: C Words: 1 Description: Cycles: 2 Encoding: 0000 Description: Q Cycle Activity: Q1 RETURN 0000 0000 0010 Q2 Q3 Q4 Decode No operation Process Data POP PC from stack No operation No operation No operation No operation Example: RETURN Encoding: 0001 101d Words: 1 Cycles: 1 Q Cycle Activity: Q1 After Interrupt ffff ffff 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'. register f C Decode f,d Q2 Q3 Q4 Read register 'f' Process Data Write to destination PC = TOS Example: RLCF REG,0 Before Instruction REG C = = 1110 0110 0 After Instruction REG WREG C DS30289A-page 220 = = = 1110 0110 1100 1100 1 1998 Microchip Technology Inc. PIC17C7XX RLNCF Rotate Left f (no carry) RRCF Rotate Right f through Carry Syntax: [ label ] RLNCF Syntax: [ label ] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] Operation: f<n> → d<n+1>; f<7> → d<0> Operation: Status Affected: None f<n> → d<n-1>; f<0> → C; C → d<7> Status Affected: C Encoding: 0010 Description: 001d f,d ffff ffff 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'. Encoding: 0001 Description: 1 Cycles: 1 Q Cycle Activity: Q1 Decode Q3 Q4 Read register 'f' Process Data Write to destination Words: 1 Cycles: 1 Q Cycle Activity: Q1 Decode RLNCF Before Instruction C REG = = 0 1110 1011 = = 1101 0111 Q2 Q3 Q4 Process Data Write to destination RRCF REG1,0 Before Instruction = = 1110 0110 0 After Instruction REG1 WREG C 1998 Microchip Technology Inc. ffff Read register 'f' Example: REG1 C After Instruction C REG REG, 1 ffff register f C Q2 Example: 100d 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'. register f Words: RRCF f,d = = = 1110 0110 0111 0011 0 DS30289A-page 221 PIC17C7XX RRNCF Rotate Right f (no carry) SETF Set f Syntax: [ label ] Syntax: [ label ] Operands: 0 ≤ f ≤ 255 d ∈ [0,1] Operands: 0 ≤ f ≤ 255 s ∈ [0,1] Operation: f<n> → d<n-1>; f<0> → d<7> Operation: FFh → f; FFh → d Status Affected: None Status Affected: None Encoding: 0010 Description: RRNCF f,d 000d 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 Words: 1 Cycles: 1 Q Cycle Activity: Q1 Q2 Q3 Q4 Process Data Write to destination RRNCF REG, 1 Before Instruction = = ? 1101 0111 After Instruction WREG REG = = Example 2: 0 1110 1011 RRNCF REG, 0 = = ? 1101 0111 After Instruction WREG REG = = DS30289A-page 222 ffff ffff Words: 1 Cycles: 1 Q2 Q3 Q4 Read register 'f' Process Data Write register 'f' and other specified register Example1: SETF REG, 0 Before Instruction REG WREG = = 0xDA 0x05 After Instruction REG WREG Example2: = 0xFF = 0xFF SETF REG, 1 Before Instruction Before Instruction WREG REG 101s 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. Q Cycle Activity: Q1 Read register 'f' Example 1: 0010 Description: Decode Decode WREG REG Encoding: SETF f,s 1110 1011 1101 0111 REG WREG = = 0xDA 0x05 After Instruction REG WREG = = 0xFF 0x05 1998 Microchip Technology Inc. PIC17C7XX SLEEP Enter SLEEP mode SUBLW Subtract WREG from Literal [ label ] SLEEP Syntax: [ label ] SUBLW k Operands: None Operands: 0 ≤ k ≤ 255 Operation: 00h → WDT; 0 → WDT postscaler; 1 → TO; 0 → PD Operation: k – (WREG) → (WREG) Status Affected: OV, C, DC, Z Syntax: Status Affected: Encoding: TO, PD Encoding: 0000 Description: 0000 0000 The processor is put into SLEEP mode with the oscillator stopped. 1 Cycles: 1 Q Cycle Activity: Q1 Decode kkkk kkkk Words: 1 Cycles: 1 Q Cycle Activity: Q1 Decode Example 1: Q2 Q3 Q4 Read literal 'k' Process Data Write to WREG SUBLW 0x02 Before Instruction Q2 Q3 Q4 No operation Process Data Go to sleep Example: SLEEP Before Instruction TO = PD = 0010 WREG is subtracted from the eight bit literal 'k'. The result is placed in WREG. 0011 The power-down status bit (PD) is cleared. The time-out status bit (TO) is set. Watchdog Timer and its postscaler are cleared. Words: 1011 Description: ? ? WREG C = = After Instruction WREG C Z = = = ; result is positive Before Instruction WREG C TO = PD = After Instruction † If WDT causes wake-up, this bit is cleared 1 1 0 Example 2: After Instruction 1† 0 1 ? WREG C Z = = = = = 2 ? 0 1 1 ; result is zero Example 3: Before Instruction WREG C = = 3 ? After Instruction WREG C Z 1998 Microchip Technology Inc. = = = FF ; (2’s complement) 0 ; result is negative 0 DS30289A-page 223 PIC17C7XX SUBWF Subtract WREG from f Syntax: [ label ] SUBWF f,d Operands: 0 ≤ f ≤ 255 d ∈ [0,1] Operation: (f) – (W) → (dest) Status Affected: OV, C, DC, Z Encoding: 0000 Description: 010d 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: 1 Cycles: 1 Q Cycle Activity: Q1 Decode Q2 Q3 Q4 Read register 'f' Process Data Write to destination SUBWFB Subtract WREG from f with Borrow Syntax: [ label ] SUBWFB f,d Operands: 0 ≤ f ≤ 255 d ∈ [0,1] Operation: (f) – (W) – C → (dest) Status Affected: OV, C, DC, Z Encoding: SUBWF 1 Cycles: 1 Q Cycle Activity: Q1 REG1, 1 Before Instruction REG1 WREG C = = = = = = = 1 2 1 0 REG1 WREG C Before Instruction = = = = = = = 0 2 1 1 REG1 WREG C = = = = DS30289A-page 224 FF 2 0 0 REG1 WREG C Z Example3: 1 2 ? SUBWFB REG1, 1 = = = 0x19 0x0D 1 (0001 1001) (0000 1101) = = = = 0x0C 0x0D 1 0 (0000 1011) (0000 1101) ; result is positive SUBWFB REG1,0 = = = 0x1B 0x1A 0 (0001 1011) (0001 1010) = = = = 0x1B 0x00 1 1 (0001 1011) SUBWFB ; result is zero REG1,1 Before Instruction REG1 WREG C After Instruction REG1 WREG C Z Q4 Write to destination After Instruction ; result is zero Before Instruction = = = Q3 Process Data Before Instruction Example 3: REG1 WREG C REG1 WREG C Z Example2: 2 2 ? After Instruction REG1 WREG C Z Q2 After Instruction ; result is positive Example 2: REG1 WREG C ffff Before Instruction After Instruction REG1 WREG C Z ffff Read register 'f' Example 1: 3 2 ? 001d 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: Decode Example 1: 0000 Description: = = = 0x03 0x0E 1 (0000 0011) (0000 1101) 0xF5 0x0E 0 0 (1111 0100) [2’s comp] (0000 1101) ; result is negative After Instruction ; result is negative REG1 WREG C Z = = = = 1998 Microchip Technology Inc. PIC17C7XX SWAPF Swap f TABLRD Table Read Syntax: [ label ] SWAPF f,d Syntax: [ label ] TABLRD t,i,f Operands: 0 ≤ f ≤ 255 d ∈ [0,1] Operands: Operation: f<3:0> → dest<7:4>; f<7:4> → dest<3:0> 0 ≤ f ≤ 255 i ∈ [0,1] t ∈ [0,1] Operation: Status Affected: None 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 Status Affected: None Encoding: 0001 110d ffff ffff Description: 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: 1 Cycles: 1 Encoding: Q Cycle Activity: Q1 Decode Q2 Q3 Q4 Read register 'f' Process Data Write to destination Example: SWAPF REG, 1010 Description: 1. 2. 0 Before Instruction REG = 0x53 After Instruction REG = 3. 0x35 ffff Words: 1 Cycles: 2 (3 cycle if f = PCL) Q Cycle Activity: Q1 Decode No operation 1998 Microchip Technology Inc. 10ti ffff 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) is loaded into the 16-bit Table Latch (TBLAT). If i = 1: TBLPTR is incremented; If i = 0: TBLPTR is not incremented Q2 Q3 Q4 Read register TBLATH or TBLATL No operation (Table Pointer on Address bus) Process Data Write register 'f' No operation No operation (OE goes low) DS30289A-page 225 PIC17C7XX TABLRD Table Read TABLWT Table Write Example1: TABLRD Syntax: [ label ] TABLWT t,i,f Operands: 0 ≤ f ≤ 255 i ∈ [0,1] t ∈ [0,1] Operation: 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 Status Affected: None 1, 1, REG ; Before Instruction REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR) = = = = = 0x53 0xAA 0x55 0xA356 0x1234 After Instruction (table write completion) REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR) Example2: TABLRD = = = = = 0xAA 0x12 0x34 0xA357 0x5678 0, 0, REG ; Before Instruction REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR) = = = = = 0x53 0xAA 0x55 0xA356 0x1234 Encoding: 1010 Description: 1. After Instruction (table write completion) REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR) = = = = = 2. 0x55 0x12 0x34 0xA356 0x1234 Note: ffff ffff 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: 1 Cycles: 2 (many if write is to on-chip EPROM program memory) Q Cycle Activity: Q1 Decode No operation DS30289A-page 226 11ti 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 is 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. Q2 Q3 Read register 'f' Process Data Q4 Write register TBLATH or TBLATL No No No operation operation operation (Table Pointer (Table Latch on on Address Address bus, bus) WR goes low) 1998 Microchip Technology Inc. PIC17C7XX TABLWT Table Write TLRD Table Latch Read Example1: TABLWT Syntax: [ label ] TLRD t,f Operands: 0 ≤ f ≤ 255 t ∈ [0,1] Operation: If t = 0, TBLATL → f; If t = 1, TBLATH → f Status Affected: None 1, 1, REG Before Instruction REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR) = = = = = 0x53 0xAA 0x55 0xA356 0xFFFF After Instruction (table write completion) REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR - 1) Example 2: TABLWT = = = = = 0x53 0x53 0x55 0xA357 0x5355 Encoding: 1010 Description: 0, 0, REG = = = = = Program Memory = = = = = 15 0x53 0xAA 0x53 0xA356 0xAA53 0 16 bits 8 7 TBLAT Words: 1 Cycles: 1 Q Cycle Activity: Q1 Decode Data Memory Q2 Q3 Q4 Read register TBLATH or TBLATL Process Data Write register 'f' Example: TLRD t, RAM Before Instruction TBLPTR 15 ffff If t = 0; low byte is read This instruction is used in conjunction with TABLRD to transfer data from program memory to data memory. 0x53 0xAA 0x55 0xA356 0xFFFF After Instruction (table write completion) REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR) ffff If t = 1; high byte is read Before Instruction REG TBLATH TBLATL TBLPTR MEMORY(TBLPTR) 00tx Read data from 16-bit table latch (TBLAT) into file register 'f'. Table Latch is unaffected. t RAM TBLAT 0 = = = 0 ? 0x00AF 8 bits (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 Program Memory = = 0x00 0x00AF (TBLATH = 0x00) (TBLATL = 0xAF) 15 0 Data Memory TBLPTR 15 16 bits 1998 Microchip Technology Inc. 8 7 TBLAT 0 8 bits DS30289A-page 227 PIC17C7XX TLWT Table Latch Write TSTFSZ Test f, skip if 0 Syntax: [ label ] TLWT t,f Syntax: [ label ] TSTFSZ f Operands: 0 ≤ f ≤ 255 t ∈ [0,1] Operands: 0 ≤ f ≤ 255 Operation: skip if f = 0 If t = 0, f → TBLATL; If t = 1, f → TBLATH Status Affected: None Operation: Status Affected: Encoding: 1010 Description: 01tx ffff 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: 1 Cycles: 1 Q Cycle Activity: Q1 Decode ffff 1 Cycles: 1 (2) Q Cycle Activity: Q1 Q2 Q3 Q4 Decode Read register 'f' Process Data No operation Q1 Q2 Q3 Q4 No operation No operation No operation No operation If skip: Q2 Q3 Q4 Read register 'f' Process Data Write register TBLATH or TBLATL Example: HERE NZERO ZERO TSTFSZ : : CNT Before Instruction PC = Address (HERE) Example: TLWT t, RAM Before Instruction t RAM TBLAT ffff Words: ffff Data from file register 'f' is written into the 16-bit table latch (TBLAT). If t = 1; high byte is written 0011 Description: None Encoding: 0011 If 'f' = 0, the next instruction, fetched during the current instruction execution, is discarded and an NOP is executed making this a two-cycle instruction. = = = 0 0xB7 0x0000 (TBLATH = 0x00) (TBLATL = 0x00) After Instruction If CNT PC If CNT PC = = ≠ = 0x00, Address (ZERO) 0x00, Address (NZERO) 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 = = DS30289A-page 228 0xB7 0xB700 (TBLATH = 0xB7) (TBLATL = 0x00) 1998 Microchip Technology Inc. PIC17C7XX Exclusive OR Literal with WREG XORWF Exclusive OR WREG with f XORLW Syntax: [ label ] XORWF Syntax: [ label ] XORLW k Operands: Operands: 0 ≤ k ≤ 255 0 ≤ f ≤ 255 d ∈ [0,1] Operation: (WREG) .XOR. k → (WREG) Operation: (WREG) .XOR. (f) → (dest) Status Affected: Z Status Affected: Z Encoding: 1011 Description: 0100 1 Cycles: 1 Q Cycle Activity: Q1 Decode Example: Q2 Q3 Q4 Read literal 'k' Process Data Write to WREG XORLW 0xAF Before Instruction = 0xB5 After Instruction WREG kkkk The contents of WREG are XOR’ed with the 8-bit literal 'k'. The result is placed in WREG. Words: WREG kkkk = 0x1A Encoding: 110d ffff ffff Description: 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: 1 Cycles: 1 Q Cycle Activity: Q1 Decode Q2 Q3 Q4 Read register 'f' Process Data Write to destination Example: XORWF REG, 1 Before Instruction REG WREG = = 0xAF 0xB5 After Instruction REG WREG 1998 Microchip Technology Inc. 0000 f,d = = 0x1A 0xB5 DS30289A-page 229 PIC17C7XX NOTES: DS30289A-page 230 1998 Microchip Technology Inc. PIC17C7XX 19.0 DEVELOPMENT SUPPORT 19.1 Development Tools The PICmicrο microcontrollers are supported with a full range of hardware and software development tools: • PICMASTER/PICMASTER CE Real-Time In-Circuit Emulator • ICEPIC Low-Cost PIC16C5X and PIC16CXXX In-Circuit Emulator • PRO MATE II Universal Programmer • PICSTART Plus Entry-Level Prototype Programmer • PICDEM-1 Low-Cost Demonstration Board • PICDEM-2 Low-Cost Demonstration Board • PICDEM-3 Low-Cost Demonstration Board • MPASM Assembler • MPLAB SIM Software Simulator • MPLAB-C17 (C Compiler) • Fuzzy Logic Development System (fuzzyTECH−MP) 19.2 PICMASTER: High Performance Universal In-Circuit Emulator with MPLAB IDE The PICMASTER Universal In-Circuit Emulator is intended to provide the product development engineer with a complete microcontroller design tool set for all microcontrollers in the PIC14C000, PIC12CXXX, PIC16C5X, PIC16CXXX and PIC17CXX families. PICMASTER is supplied with the MPLAB Integrated Development Environment (IDE), which allows editing, “make” and download, and source debugging from a single environment. Interchangeable target probes allow the system to be easily reconfigured for emulation of different processors. The universal architecture of the PICMASTER allows expansion to support all new Microchip microcontrollers. The PICMASTER 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 compatible 386 (and higher) machine platform and Microsoft Windows 3.x environment were chosen to best make these features available to you, the end user. 19.3 ICEPIC: Low-cost PICmicro™ In-Circuit Emulator ICEPIC is a low-cost in-circuit emulator solution for the Microchip PIC12CXXX, PIC16C5X and PIC16CXXX families of 8-bit OTP microcontrollers. ICEPIC is designed to operate on PC-compatible machines ranging from 286-AT through Pentium based machines under Windows 3.x environment. ICEPIC features real time, non-intrusive emulation. 19.4 PRO MATE II: Universal Programmer The PRO MATE II Universal Programmer is a full-featured programmer capable of operating in stand-alone mode as well as PC-hosted mode. PRO MATE II is CE compliant. The PRO MATE II has programmable VDD and VPP supplies which allows it to verify programmed memory at VDD min and VDD max for maximum reliability. It has an LCD display for displaying error messages, keys to enter commands and a modular detachable socket assembly to support various package types. In standalone mode the PRO MATE II can read, verify or program PIC12CXXX, PIC14C000, PIC16C5X, PIC16CXXX and PIC17CXX devices. It can also set configuration and code-protect bits in this mode. 19.5 PICSTART Plus Entry Level Development System The PICSTART programmer is an easy-to-use, low-cost prototype programmer. It connects to the PC via one of the COM (RS-232) ports. MPLAB Integrated Development Environment software makes using the programmer simple and efficient. PICSTART Plus is not recommended for production programming. PICSTART Plus supports all PIC12CXXX, PIC14C000, PIC16C5X, PIC16CXXX and PIC17CXX devices with up to 40 pins. Larger pin count devices such as the PIC16C923, PIC16C924 and PIC17C756 may be supported with an adapter socket. PICSTART Plus is CE compliant. A CE compliant version of PICMASTER is available for European Union (EU) countries. 1998 Microchip Technology Inc. DS30289A-page 231 PIC17C7XX 19.6 PICDEM-1 Low-Cost PICmicro™ Demonstration Board The PICDEM-1 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 users can program the sample microcontrollers provided with the PICDEM-1 board, on a PRO MATE II or PICSTART-Plus programmer, and easily test firmware. The user can also connect the PICDEM-1 board to the PICMASTER emulator and download the firmware to the emulator for testing. Additional 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. 19.7 PICDEM-2 Low-Cost PIC16CXX Demonstration Board The PICDEM-2 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 board, on a PRO MATE II programmer or PICSTART-Plus, and easily test firmware. The PICMASTER emulator may also be used with the PICDEM-2 board to test firmware. Additional 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 I2C bus and separate headers for connection to an LCD module and a keypad. 19.8 PICDEM-3 Low-Cost PIC16CXXX Demonstration Board The PICDEM-3 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 a 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 board, on a PRO MATE II programmer or PICSTART Plus with an adapter socket, and easily test firmware. The PICMASTER emulator may also be used with the PICDEM-3 board to test firmware. Additional prototype area has been provided to the user for adding hardware and connecting it to the microcontroller socket(s). Some of the features include DS30289A-page 232 an 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 board is an LCD panel, with 4 commons and 12 segments, that is capable of displaying time, temperature and day of the week. The PICDEM-3 provides an additional RS-232 interface and Windows 3.1 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. 19.9 MPLAB™ Integrated Development Environment Software The MPLAB IDE Software brings an ease of software development previously unseen in the 8-bit microcontroller market. MPLAB is a windows based application which contains: • A full featured editor • Three operating modes - editor - emulator - simulator • A project manager • Customizable tool bar and key mapping • A status bar with project information • Extensive on-line help MPLAB allows you to: • Edit your source files (either assembly or ‘C’) • One touch assemble (or compile) and download to PICmicro tools (automatically updates all project information) • Debug using: - source files - absolute listing file • Transfer data dynamically via DDE (soon to be replaced by OLE) • Run up to four emulators on the same PC The ability to use MPLAB with Microchip’s simulator allows a consistent platform and the ability to easily switch from the low cost simulator to the full featured emulator with minimal retraining due to development tools. 19.10 Assembler (MPASM) The MPASM Universal Macro Assembler is a PC-hosted symbolic assembler. It supports all microcontroller series including the PIC12C5XX, PIC14000, PIC16C5X, PIC16CXXX, and PIC17CXX families. MPASM offers full featured Macro capabilities, conditional assembly, and several source and listing formats. It generates various object code formats to support Microchip's development tools as well as third party programmers. MPASM allows full symbolic debugging from PICMASTER, Microchip’s Universal Emulator System. 1998 Microchip Technology Inc. PIC17C7XX MPASM has the following features to assist in developing software for specific use applications. • Provides translation of Assembler source code to object code for all Microchip microcontrollers. • Macro assembly capability. • Produces all the files (Object, Listing, Symbol, and special) required for symbolic debug with Microchip’s emulator systems. • Supports Hex (default), Decimal and Octal source and listing formats. MPASM provides a rich directive language to support programming of the PICmicro. Directives are helpful in making the development of your assemble source code shorter and more maintainable. 19.11 Software Simulator (MPLAB-SIM) The MPLAB-SIM Software Simulator allows code development in a PC host environment. It allows the user to simulate the PICmicro series microcontrollers on an instruction level. On any given instruction, the user may examine or modify any of the data areas or provide external stimulus to any of the pins. The input/output radix can be set by the user and the execution can be performed in; single step, execute until break, or in a trace mode. MPLAB-SIM fully supports symbolic debugging using MPLAB-C and MPASM. The Software Simulator offers the low cost flexibility to develop and debug code outside of the laboratory environment making it an excellent multi-project software development tool. 19.12 C Compiler (MPLAB-C17) 19.14 MP-DriveWay – Application Code Generator MP-DriveWay is an easy-to-use Windows-based Application Code Generator. With MP-DriveWay you can visually configure all the peripherals in a PICmicro device and, with a click of the mouse, generate all the initialization and many functional code modules in C language. The output is fully compatible with Microchip’s MPLAB-C C compiler. The code produced is highly modular and allows easy integration of your own code. MP-DriveWay is intelligent enough to maintain your code through subsequent code generation. 19.15 SEEVAL Evaluation and Programming System The SEEVAL SEEPROM Designer’s Kit supports all Microchip 2-wire and 3-wire Serial EEPROMs. The kit includes everything necessary to read, write, erase or program special features of any Microchip SEEPROM product including Smart Serials and secure serials. The Total Endurance Disk is included to aid in trade-off analysis and reliability calculations. The total kit can significantly reduce time-to-market and result in an optimized system. 19.16 KEELOQ Evaluation and Programming Tools KEELOQ evaluation and programming tools support Microchips HCS Secure Data Products. The HCS evaluation kit includes an LCD display to show changing codes, a decoder to decode transmissions, and a programming interface to program test transmitters. The MPLAB-C Code Development System is a complete ‘C’ compiler and integrated development environment for Microchip’s PIC17CXXX family of microcontrollers. The compiler provides powerful integration capabilities and ease of use not found with other compilers. For easier source level debugging, the compiler provides symbol information that is compatible with the MPLAB IDE memory display. 19.13 Fuzzy Logic Development System (fuzzyTECH-MP) fuzzyTECH-MP fuzzy logic development tool is available in two versions - a low cost introductory version, MP Explorer, for designers to gain a comprehensive working knowledge of fuzzy logic system design; and a full-featured version, fuzzyTECH-MP, Edition for implementing more complex systems. Both versions include Microchip’s fuzzyLAB demonstration board for hands-on experience with fuzzy logic systems implementation. 1998 Microchip Technology Inc. DS30289A-page 233 PIC16C5X PIC16CXXX PIC16C6X PIC16C7XX PIC16C8X PIC16C9XX PIC17C4X ü ü ü ü ü ü ü ü ü ü ü ü ü ü ü ü ü ü ü PIC17C7XX 24CXX 25CXX 93CXX HCSXXX EMULATOR PRODUCTS (PIC17C75X only) ü ü ü ü ü ü ü ü MPLAB™-ICE ICEPIC Low-Cost In-Circuit Emulator DEVELOPMENT TOOLS FROM MICROCHIP PICMASTER/ PICMASTER-CE In-Circuit Emulator ü SOFTWARE PRODUCTS MPLAB Integrated Development Environment ü ü MPLAB C17 Compiler fuzzyTECH-MP Explorer/Edition Fuzzy Logic Dev. Tool ü ü MP-DriveWay Applications Code Generator ü ü ü ü ü ü ü ü ü ü ü ü ü ü Total Endurance Software Model ü PROGRAMMERS 1998 Microchip Technology Inc. PICSTARTPlus Low-Cost Universal Dev. Kit ü ü ü ü ü ü ü ü ü ü PRO MATE II Universal Programmer ü ü ü ü ü ü ü ü ü ü ü ü ü KEELOQ Programmer ü ü DEMO BOARDS ü SEEVAL Designers Kit PICDEM-1 PICDEM-2 PICDEM-3 KEELOQ Evaluation Kit ü ü ü ü ü ü PIC17C7XX PIC14000 TABLE 19-1: DS30289A-page 234 PIC12C5XX PIC17C7XX 20.0 PIC17C7 MXX ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings † Ambient temperature under bias............................................................................................................. -55˚C to +125˚C Storage temperature .............................................................................................................................. -65˚C to +150˚C Voltage on VDD with respect to VSS ............................................................................................................. 0V to +7.5V Voltage on MCLR with respect to VSS (Note 2).......................................................................................... -0.3V to +14V Voltage on RA2 and RA3 with respect to VSS ............................................................................................ -0.3V to +8.5V Voltage on all other pins with respect to VSS .................................................................................... -0.3V to VDD + 0.3V Total power dissipation (Note 1)................................................................................................................................1.0W Maximum current out of VSS pin(s) - total (@ 70˚C) ............................................................................................500 mA Maximum current into VDD pin(s) - total (@ 70˚C) ...............................................................................................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) Note 2: Voltage spikes below VSS at the MCLR pin, inducing currents greater than 80 mA, may cause latch-up. Thus, a series resistor of 50-100Ω 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. 1998 Microchip Technology Inc. Preliminary DS30289A-page 235 PIC17C7XX TABLE 20-1: OSC RC XT EC LF CROSS REFERENCE OF DEVICE SPECS FOR OSCILLATOR CONFIGURATIONS AND FREQUENCIES OF OPERATION (COMMERCIAL DEVICES) PIC17LC7XX-08 PIC17C7XX-16 PIC17C7XX-33 JW Devices (Ceramic Windowed Devices) VDD: 3.0V to 5.5V IDD †: 6 mA max. IPD †: 5 µA max. at 5.5V Freq: 4 MHz max. VDD: 3.0V to 5.5V IDD †: 12 mA max. IPD †: 5 µA max. at 5.5V Freq: 8 MHz max. VDD: 3.0V to 5.5V IDD †: 12 mA max. IPD †: 5 µA max. at 5.5V Freq: 8 MHz max. VDD: 4.5V to 5.5V IDD †: 6 mA max. IPD †: 5 µA max. at 5.5V Freq: 4 MHz max. VDD: 4.5V to 5.5V IDD †: 6 mA max. IPD †: 5 µA max. at 5.5V Freq: 4 MHz max. VDD: 4.5V to 5.5V IDD †: 6 mA max. IPD †: 5 µA max. at 5.5V Freq: 4 MHz max. VDD: 4.5V to 5.5V IDD †: 38 mA max. IPD †: 5 µA max. at 5.5V Freq: 16 MHz max. VDD: 4.5V to 5.5V IDD †: 38 mA max. IPD †: 5 µA max. at 5.5V Freq: 16 MHz max. VDD: 4.5V to 5.5V IDD †: 50 mA max. IPD †: 5 µA max. at 5.5V Freq: 33 MHz max. VDD: 4.5V to 5.5V IDD †: 50 mA max. IPD †: 5 µA max. at 5.5V Freq: 33 MHz max. VDD: 4.5V to 5.5V IDD †: 50 mA max. IPD †: 5 µA max. at 5.5V Freq: 33 MHz max. VDD: 4.5V to 5.5V IDD †: 50 mA max. IPD †: 5 µA max. at 5.5V Freq: 33 MHz max. VDD: 3.0V to 5.5V IDD †: 115 µA max. at 32 kHz IPD †: 5 µA max. at 5.5V Freq: 2 MHz max. VDD: 4.5V to 5.5V IDD †: 85 µA typ. at 32 kHz IPD †: < 1 µA typ. at 5.5V Freq: 2 MHz max. VDD: 4.5V to 5.5V IDD †: 85 µA typ. at 32 kHz IPD †: < 1 µA typ. at 5.5V Freq: 2 MHz max. VDD: 3.0V to 5.5V IDD †: 115 µA max. at 32 kHz IPD †: 5 µA max. at 5.5V Freq: 2 MHz max. The shaded sections indicate oscillator selections which are tested for functionality, but not for MIN/MAX specifications. It is recommended that the user select the device type that ensures the specifications required. † The WDT, BOR,and A/D circuitry are disabled. DS30289A-page 236 Preliminary 1998 Microchip Technology Inc. PIC17C7XX 20.1 DC CHARACTERISTICS PIC17C7XX-16 (Commercial, Industrial) PIC17C7XX-33 (Commercial, Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40˚C ≤ TA ≤ +85˚C for industrial and 0˚C ≤ TA ≤ +70˚C for commercial DC CHARACTERISTICS Param. No. D001 Sym VDD Characteristic Supply Voltage Min Typ† Max Unit s 4.5 – 5.5 V VBOR * – 5.5 V 1.5 * – – V Device in SLEEP mode Conditions PIC17C7XX - 33, PIC17C7XX - 16 PIC17C7XX - 16 (BOR enabled)(Note 5) D002 VDR RAM Data Retention Voltage (Note 1) D003 VPOR VDD start voltage to ensure internal Power-on Reset signal – VSS – V See section on Power-on Reset for details D004 SVDD VDD rise rate to ensure proper operation 0.085 * – – V/ms See section on Power-on Reset for details D005 VBOR Brown-out Reset voltage trip point 3.65 – 4.35 V D006 VPORTP Power-on Reset trip point – 2.2 – V D010 D011 D012 D013 D015 IDD Supply Current (Note 2) – – – – – TBD TBD TBD TBD TBD 6* 12 24 * 38 * 50 mA mA mA mA mA * † Note 1: 2: 3: 4: 5: VDD = VPORTP FOSC = 4 MHz (Note 4) FOSC = 8 MHz FOSC = 16 MHz FOSC = 25 MHz FOSC = 33 MHz These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25˚C unless otherwise stated. These parameters are for design guidance only and are not tested. This is the limit to which VDD can be lowered in SLEEP mode without losing RAM data. 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 tristated, 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 (C L • 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). 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. 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. 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. 1998 Microchip Technology Inc. Preliminary DS30289A-page 237 PIC17C7XX Standard Operating Conditions (unless otherwise stated) Operating temperature -40˚C ≤ TA ≤ +85˚C for industrial and 0˚C ≤ TA ≤ +70˚C for commercial DC CHARACTERISTICS Param. No. D021 Sym IPD Characteristic Power-down Current (Note 3) Min Typ† Max Unit s Conditions – <1 20 µA VDD = 5.5V, WDT disabled Module Differential Current D023 ∆IBOR BOR circuitry – 150 300 µA VDD = 4.5V, BODEN enabled D024 ∆IWDT Watchdog Timer – 10 35 µA VDD = 5.5V D026 ∆IAD A/D converter – 1 – µA VDD = 5.5V, A/D not converting * † Note 1: 2: 3: 4: 5: These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25˚C unless otherwise stated. These parameters are for design guidance only and are not tested. This is the limit to which VDD can be lowered in SLEEP mode without losing RAM data. 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 tristated, 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 (C L • 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). 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. 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. 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. DS30289A-page 238 Preliminary 1998 Microchip Technology Inc. PIC17C7XX 20.2 DC CHARACTERISTICS PIC17LC7XX -08(Commercial, Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40˚C ≤ TA ≤ +85˚C for industrial and 0˚C ≤ TA ≤ +70˚C for commercial DC CHARACTERISTICS Param. No. Sym Characteristic Min Typ† Max Units 3.0 – 5.5 V Conditions D001 VDD Supply Voltage D002 VDR RAM Data Retention Voltage (Note 1) 1.5 * – – V Device in SLEEP mode D003 VPOR VDD start voltage to ensure internal Power-on Reset signal – VSS – V See section on Power-on Reset for details D004 SVDD VDD rise rate to ensure proper operation 0.010 * – – V/ms See section on Power-on Reset for details D005 VBOR Brown-out Reset voltage trip point 3.65 – 4.35 V D006 VPORTP Power-on Reset trip point – 2.2 – V D010 D011 D014 IDD Supply Current (Note 2) – – – 3 6 85 6 * 12 150 mA mA µA FOSC = 4 MHz (Note 4) FOSC = 8 MHz FOSC = 32 kHz, (EC osc configuration) D021 IPD Power-down Current (Note 3) – <1 5 µA VDD = 3.0V, WDT disabled VDD = VPORTP * † These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25˚C unless otherwise stated. These parameters are for design guidance only and are not tested. 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 tristated, 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 (C L • 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. 1998 Microchip Technology Inc. Preliminary DS30289A-page 239 PIC17C7XX Standard Operating Conditions (unless otherwise stated) Operating temperature -40˚C ≤ TA ≤ +85˚C for industrial and 0˚C ≤ TA ≤ +70˚C for commercial DC CHARACTERISTICS Param. No. Sym Characteristic Min Typ† Max Units Conditions Module Differential Current D023 ∆IBOR BOR circuitry – 150 300 µA VDD = 4.5V, BODEN enabled D024 ∆IWDT Watchdog Timer – 10 35 µA VDD = 5.5V D026 ∆IAD A/D converter – 1 – µA VDD = 5.5V, A/D not converting * † These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25˚C unless otherwise stated. These parameters are for design guidance only and are not tested. 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 tristated, 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 (C L • 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. DS30289A-page 240 Preliminary 1998 Microchip Technology Inc. PIC17C7XX 20.3 DC CHARACTERISTICS PIC17C7XX-16 (Commercial, Industrial) PIC17C7XX-33( Commercial, Industrial) PIC17LC7XX-08 (Commercial, Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40˚C ≤ TA ≤ +85˚C for industrial and 0˚C ≤ TA ≤ +70˚C for commercial Operating voltage VDD range as described in Section 20.1 DC CHARACTERISTICS Param. No. Sym VIL Characteristic D030 with TTL buffer (Note 6) D031 with Schmitt Trigger buffer RA2, RA3 All others MCLR, OSC1 (in EC and RC mode) OSC1 (in XT, and LF mode) D032 D033 Min Typ† Max Units Conditions VSS VSS – – 0.8 0.2VDD V V 4.5V ≤ VDD ≤ 5.5V 3.0V ≤ VDD ≤ 4.5V VSS VSS – – 0.3VDD 0.2VDD V V I2C compliant VSS – 0.2VDD V Note1 – 0.5VDD – V 2.0 1 + 0.2VDD – – VDD VDD V V 4.5V ≤ VDD ≤ 5.5V 3.0V ≤ VDD ≤ 4.5V 0.7VDD 0.8VDD – – VDD VDD V V I2C compliant 0.8VDD – – 0.5VDD VDD – V V Note1 Input Low Voltage I/O ports Input High Voltage VIH I/O ports D040 with TTL buffer (Note 6) D041 with Schmitt Trigger buffer RA2, RA3 All others D042 MCLR OSC1 (XT, and LF mode) D043 D050 * † ‡ Note 1: 2: 3: 4: 5: 6: Hysteresis of 0.15VDD * – – V Schmitt Trigger inputs These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. These parameters are for design guidance only and are not tested, nor characterized. 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. The specified levels represent normal operating conditions. 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. VHYS 1998 Microchip Technology Inc. Preliminary DS30289A-page 241 PIC17C7XX DC CHARACTERISTICS Param. No. D060 D061 D062 Sym IIL Characteristic Input Leakage Current (Notes 2, 3) I/O ports (except RA2, RA3) MCLR, TEST RA2, RA3 Standard Operating Conditions (unless otherwise stated) Operating temperature -40˚C ≤ TA ≤ +85˚C for industrial and 0˚C ≤ TA ≤ +70˚C for commercial Operating voltage VDD range as described in Section 20.1 Min Typ† Max Units Conditions – – ±1 µA Vss ≤ VPIN ≤ VDD, I/O Pin (in digital mode) at hi-impedance PORTB weak pull-ups disabled – – ±2 ±2 µA VPIN = Vss or VPIN = VDD µA Vss ≤ VRA2, VRA3 ≤ 12V µA Vss ≤ VPIN ≤ VDD D063 OSC1 (EC, RC modes) – – ±1 D063B OSC1 (XT, LF modes) – – VPIN MCLR, TEST – – 25 µA VMCLR = VPP = 12V (when not programming) 60 200 400 µA D064 D070 * † ‡ Note 1: 2: 3: 4: 5: 6: IPURB PORTB weak pull-up current µA RF ≥ 1 MΩ VPIN = VSS, RBPU = 0 4.5V ≤ VDD ≤ 5.5V These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. These parameters are for design guidance only and are not tested, nor characterized. 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. The specified levels represent normal operating conditions. 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. DS30289A-page 242 Preliminary 1998 Microchip Technology Inc. PIC17C7XX Standard Operating Conditions (unless otherwise stated) Operating temperature -40˚C ≤ TA ≤ +85˚C for industrial and 0˚C ≤ TA ≤ +70˚C for commercial Operating voltage VDD range as described in Section 20.1 DC CHARACTERISTICS Param. No. D080 Sym VOL Characteristic Typ† Max Units – – – – – – 0.1VDD 0.1VDD * 0.4 V V V – – – – – – – – – – 3.0 0.4 0.6 0.4 0.1VDD * V V V V V 0.9VDD 0.9VDD * 2.4 – – – – – – V V V 2.4 0.9VDD * – – – – V V – – 8.5 V pF In EC or RC osc modes when OSC2 pin is outputting CLKOUT. External clock is used to drive OSC1. pF Output Low Voltage I/O ports with TTL buffer D081 Min D082 RA2 and RA3 D083 D084 OSC2/CLKOUT (RC and EC osc modes) Conditions 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 = 2.5V IOL = 60.0 mA, VDD = 4.5V IOL = 1 mA, VDD = 4.5V IOL = VDD/5 mA (PIC17LC7XX only) Output High Voltage (Note 3) D090 VOH I/O ports (except RA2 and RA3) with TTL buffer D091 OSC2/CLKOUT (RC and EC osc modes) D093 D094 Open Drain High Voltage D150 VOD D100 Capacitive Loading Specs on Output Pins Cosc2 OSC2/CLKOUT pin – – 25 ‡ D101 CIO – – 50 ‡ D102 CAD – – 50 ‡ * † ‡ Note 1: 2: 3: 4: 5: 6: All I/O pins and OSC2 (in RC mode) System Interface Bus (PORTC, PORTD and PORTE) 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) RA2 and RA3 pins only pulled-up to externally applied voltage pF In Microprocessor or Extended Microcontroller mode These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. These parameters are for design guidance only and are not tested, nor characterized. 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. The specified levels represent normal operating conditions. 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. 1998 Microchip Technology Inc. Preliminary DS30289A-page 243 PIC17C7XX Standard Operating Conditions (unless otherwise stated) Operating temperature -40˚C ≤ TA ≤ +40˚C Operating voltage VDD range as described in Section 20.1 DC CHARACTERISTICS Param. No. Sym Characteristic Min Typ† Max Units Conditions 12.75 4.75 – 5.0 13.25 5.25 V V – – 25 ‡ – 50 ‡ 30 ‡ mA mA 100 – 1000 ms Terminated via internal/external interrupt or a reset Internal Program Memory Programming Specs (Note 4) D110 D111 D112 D113 D114 * † ‡ Note 1: 2: 3: 4: 5: 6: VPP VDDP Voltage on MCLR/VPP pin Supply voltage during programming Current into MCLR/VPP pin IPP Supply current during IDDP programming TPROG Programming pulse width Note 5 These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. These parameters are for design guidance only and are not tested, nor characterized. In RC oscillator configuration, the OSC1/CLKIN pin is a Schmitt Trigger input. It is not recommended that the PIC17CXX devices be driven with external clock in RC mode. The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified levels represent normal operating conditions. Higher leakage current may be measured at different input voltages. 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: PIC17CXX Programming Specifications (Literature number DS30139). 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. Note 1: When using the Table Write for internal programming, the device temperature must be less than 40˚C. Note 2: For In-Circuit Serial Programming (ICSP), refer to the device programming specification. DS30289A-page 244 Preliminary 1998 Microchip Technology Inc. PIC17C7XX 20.4 Timing Parameter Symbology The timing parameter symbols have been created following one of the following formats: 1. TppS2ppS 3. TCC:ST (I2C specifications only) 2. TppS 4. Ts (I2C specifications only) T F Frequency T Time Lowercase symbols (pp) and their meanings: pp ad Address/Data ost Oscillator Start-Up Timer al ALE pwrt Power-Up Timer cc Capture1 and Capture2 rb PORTB ck CLKOUT or clock rd RD dt Data in rw RD or WR in INT pin t0 T0CKI io I/O port t123 TCLK12 and TCLK3 mc MCLR wdt Watchdog Timer oe OE wr WR os OSC1 Uppercase symbols and their meanings: S D Driven L Low E Edge P Period F Fall R Rise H High V Valid I Invalid (Hi-impedance) Z Hi-impedance 1998 Microchip Technology Inc. Preliminary DS30289A-page 245 PIC17C7XX FIGURE 20-1: PARAMETER MEASUREMENT INFORMATION All timings are measure between high and low measurement points as indicated in the figures 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 0.25V 0.25V 0.25V Data out valid Output driven Output hi-impedance Data out invalid 0.9 VDD 0.1 VDD Rise Time Fall Time LOAD CONDITIONS Load Condition 1 Pin CL VSS 50 pF ≤ CL DS30289A-page 246 Preliminary 1998 Microchip Technology Inc. PIC17C7XX 20.5 Timing Diagrams and Specifications FIGURE 20-2: EXTERNAL CLOCK TIMING Q4 Q1 Q3 Q2 Q4 Q1 OSC1 3 1 3 2 4 4 OSC2 † † In EC and RC modes only. TABLE 20-2: Param No. Sym Fosc 1 Tosc EXTERNAL CLOCK TIMING REQUIREMENTS Min Typ† Max Units External CLKIN Frequency (Note 1) Characteristic DC DC DC — — — 8 16 33 MHz MHz MHz EC osc mode - 08 devices (8 MHz devices) - 16 devices (16 MHz devices) - 33 devices (33 MHz devices) Oscillator Frequency (Note 1) DC 2 2 2 DC 125 62.5 30.3 — — — — — — — — 4 8 16 33 2 — — — MHz MHz MHz MHz MHz ns ns ns 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) 250 125 62.5 30.3 500 121.2 — — — — — 4/Fosc — 1,000 1,000 1,000 — DC ns ns ns ns ns ns RC osc mode XT osc mode - 08 devices (8 MHz devices) - 16 devices (16 MHz devices) - 33 devices (33 MHz devices) LF osc mode External CLKIN Period (Note 1) Oscillator Period (Note 1) 2 TCY 3 TosL, TosH Clock in (OSC1) high or low time 10 ‡ — — ns EC oscillator 4 TosR, TosF Clock in (OSC1) rise or fall time — — 5‡ ns EC oscillator † ‡ Note 1: Instruction Cycle Time (Note 1) Conditions Data in “Typ” column is at 5V, 25˚C unless otherwise stated. These parameters are for design guidance only and are not tested. These parameters are for design guidance only and are not tested, nor characterized. 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. 1998 Microchip Technology Inc. Preliminary DS30289A-page 247 PIC17C7XX FIGURE 20-3: CLKOUT AND I/O TIMING Q1 Q4 Q2 Q3 OSC1 11 10 22 23 OSC2 † 13 12 18 14 16 19 I/O Pin (input) 15 17 I/O Pin (output) new value old value 20, 21 † In EC and RC modes only. TABLE 20-3: Param No. CLKOUT AND I/O TIMING REQUIREMENTS Min Typ † Max Units Conditions OSC1↓ to CLKOUT↓ — 15 ‡ 30 ‡ ns Note 1 OSC1↓ to CLKOUT↑ — 15 ‡ 30 ‡ ns Note 1 12 TckR CLKOUT rise time — 5‡ 15 ‡ ns Note 1 13 TckF CLKOUT fall time — 5‡ 15 ‡ ns Note 1 14 TckH2ioV CLKOUT ↑ to Port out valid — — 0.5TCY + 20 ‡ ns Note 1 15 TioV2ckH Port in valid before CLKOUT↑ 0.25TCY + 25 ‡ — — ns Note 1 16 TckH2ioI Port in hold after CLKOUT↑ 0‡ — — ns Note 1 17 TosL2ioV OSC1↓ (Q1 cycle) to Port out valid — — 100 ‡ ns 18 TosL2ioI OSC1↓ (Q2 cycle) to Port input invalid (I/O in hold time) 0‡ — — ns 19 TioV2osL Port input valid to OSC1↓ (I/O in setup time) 30 ‡ — — ns 20 TioR Port output rise time — 10 ‡ 35 ‡ ns 21 TioF Port output fall time — 10 ‡ 35 ‡ ns 22 TinHL INT pin high or low time 25 * — — ns 23 TrbHL RB7:RB0 change INT high or low time 25 * — — ns Sym Characteristic 10 TosL2ckL 11 TosL2ckH * † ‡ Note 1: These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. These parameters are for design guidance only and are not tested, nor characterized. Measurements are taken in EC Mode where CLKOUT output is 4 x TOSC. DS30289A-page 248 Preliminary 1998 Microchip Technology Inc. PIC17C7XX FIGURE 20-4: 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 32 OSC Time-out Internal RESET Watchdog Timer RESET 31 35 Address / Data TABLE 20-4: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER, AND BROWN-OUT RESET REQUIREMENTS Param. No. Sym 30 TmcL MCLR Pulse Width (low) 31 TWDT Watchdog Timer Time-out Period (Postscale = 1) 32 TOST Oscillation Start-up Timer Period 33 TPWRT 34 TIOZ 35 TmcL2adI 36 * † ‡ § TBOR Characteristic Min Power-up Timer Period MCLR to I/O hi-impedance MCLR to System Interface bus (AD15:AD0>) invalid Typ† Max Units 100 * — — ns 5* 12 25 * ms VDD = 5V VDD = 5V — 1024TOSC§ — ms TOSC = OSC1 period 40 * 96 200 * ms VDD = 5V Depends on pin load 100 ‡ — — ns PIC17C7XX — — 100 * ns PIC17LC7XX — — 120 * ns 100 * — — ns Brown-out Reset Pulse Width (low) Conditions 3.9V ≤ VDD ≤ 4.2V These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25∞C unless otherwise stated. These parameters are for design guidance only and are not tested. These parameters are for design guidance only and are not tested, nor characterized. This specification ensured by design. 1998 Microchip Technology Inc. Preliminary DS30289A-page 249 PIC17C7XX FIGURE 20-5: TIMER0 EXTERNAL CLOCK TIMINGS RA1/T0CKI 40 41 42 TABLE 20-5: Param No. TIMER0 EXTERNAL CLOCK REQUIREMENTS Sym Characteristic 40 Min Typ† Max Units Conditions Tt0H T0CKI High Pulse Width No Prescaler 0.5TCY + 20 § — — ns 41 Tt0L T0CKI Low Pulse Width With Prescaler No Prescaler With Prescaler 10* 0.5TCY + 20 § 10* — — — — — — ns ns ns 42 Tt0P T0CKI Period — — ns * † Greater of: 20 ns or TCY + 40 § N N = prescale value (1, 2, 4, ..., 256) These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25˚C unless otherwise stated. These parameters are for design guidance only and are not tested. This specification ensured by design. § FIGURE 20-6: TIMER1, TIMER2, AND TIMER3 EXTERNAL CLOCK TIMINGS TCLK12 or TCLK3 46 45 47 48 48 TMRx TABLE 20-6: TIMER1, TIMER2, AND TIMER3 EXTERNAL CLOCK REQUIREMENTS Param No. Sym 45 Tt123H 46 Tt123L 47 Tt123P TCLK12 and TCLK3 input period 48 * † § Min Typ † Max TCLK12 and TCLK3 high time 0.5TCY + 20 § — — TCLK12 and TCLK3 low time 0.5TCY + 20 § — — ns TCY + 40 § N 2TOSC § — — ns Characteristic Units Conditions ns N = prescale value (1, 2, 4, 8) TckE2tmrI Delay from selected External Clock Edge to — 6Tosc § — Timer increment These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25∞C unless otherwise stated. These parameters are for design guidance only and are not tested. This specification ensured by design. DS30289A-page 250 Preliminary 1998 Microchip Technology Inc. PIC17C7XX FIGURE 20-7: CAPTURE TIMINGS CAP pin (Capture Mode) 50 51 52 TABLE 20-7: Param No. CAPTURE REQUIREMENTS Sym Characteristic Min 50 TccL Capture pin input low time 10 * — — 51 TccH Capture pin input high time 10 * — — ns 52 TccP Capture pin input period 2TCY § N — — ns * † Typ† Max Units Conditions ns N = prescale value (4 or 16) These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25∞C unless otherwise stated. These parameters are for design guidance only and are not tested. This specification ensured by design. § FIGURE 20-8: PWM TIMINGS PWM pin (PWM Mode) 53 TABLE 20-8: Param No. * † § 54 PWM REQUIREMENTS Sym Characteristic Min Typ† Max Units Conditions 53 TccR PWM pin output rise time — 10 * 35 * ns 54 TccF PWM pin output fall time — 10 * 35 * ns These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25∞C unless otherwise stated. These parameters are for design guidance only and are not tested. This specification ensured by design. 1998 Microchip Technology Inc. Preliminary DS30289A-page 251 PIC17C7XX FIGURE 20-9: SPI MASTER MODE TIMING (CKE = 0) SS 70 SCK (CKP = 0) 71 72 78 79 79 78 SCK (CKP = 1) 80 BIT6 - - - - - -1 MSb SDO LSb 75, 76 SDI MSb IN BIT6 - - - -1 LSb IN 74 73 Refer to Figure 20-1 for load conditions. TABLE 20-9: Param. No. 70 71 SPI MODE REQUIREMENTS (MASTER MODE, CKE = 0) Symbol TssL2scH, TssL2scL TscH 73A SS↓ to SCK↓ or SCK↑ input TCY * Typ† Max Units — — ns ns Continuous 1.25TCY + 30 * — — Single Byte — — ns TscL SCK input low time (slave mode) Continuous 1.25TCY + 30 * — — ns Single Byte TdiV2scH, TdiV2scL TB2B 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 72A 73 Min SCK input high time (slave mode) 71A 72 Characteristic 40 40 — — ns 100 * — — ns 1.5TCY + 40 * — — ns 100 * — — ns 75 TscH2diL, TscL2diL TdoR SDO data output rise time — 10 25 * ns 76 TdoF SDO data output fall time — 10 25 * ns 78 TscR SCK output rise time (master mode) — 10 25 * ns 79 TscF SCK output fall time (master mode) — 10 25 * ns 74 Conditions Note 1 Note 1 Note 1 TscH2doV, SDO data output valid after SCK edge — — 50 * ns TscL2doV * Characterized but not tested. † Data in "Typ" column is at 5V, 25˚C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: Specification 73A is only required if specifications 71A and 72A are used. 80 DS30289A-page 252 Preliminary 1998 Microchip Technology Inc. PIC17C7XX FIGURE 20-10: SPI MASTER MODE TIMING (CKE = 1) SS 81 SCK (CKP = 0) 71 72 79 73 SCK (CKP = 1) 80 78 LSb BIT6 - - - - - -1 MSb SDO 75, 76 SDI MSb IN BIT6 - - - -1 LSb IN 74 Refer to Figure 20-1 for load conditions. TABLE 20-10: SPI MODE REQUIREMENTS (MASTER MODE, CKE = 1) Param. No. 71 Symbol TscH 71A 72 TscL Characteristic SCK input high time (slave mode) SCK input low time (slave mode) 72A 73 73A TdiV2scH, TdiV2scL TB2B Min Typ† Max Units Continuous 1.25TCY + 30 * — — ns Single Byte — — ns — — ns — — ns 100 * — — ns 1.5TCY + 40 * — — ns 100 * — — ns 40 Continuous 1.25 TCY + 30 * Single Byte 40 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 75 TscH2diL, TscL2diL TdoR SDO data output rise time — 10 25 * ns 76 TdoF SDO data output fall time — 10 25 * ns 78 TscR SCK output rise time (master mode) — 10 25 * ns 79 TscF SCK output fall time (master mode) — 10 25 * ns 74 Conditions Note 1 Note 1 Note 1 TscH2doV, SDO data output valid after SCK edge — — 50 * ns TscL2doV — — ns TdoV2scH, SDO data output setup to SCK edge TCY * 81 TdoV2scL * Characterized but not tested. † Data in "Typ" column is at 5V, 25˚C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: Specification 73A is only required if specifications 71A and 72A are used. 80 1998 Microchip Technology Inc. Preliminary DS30289A-page 253 PIC17C7XX FIGURE 20-11: SPI SLAVE MODE TIMING (CKE = 0) SS 70 SCK (CKP = 0) 83 71 72 78 79 79 78 SCK (CKP = 1) 80 MSb SDO LSb BIT6 - - - - - -1 77 75, 76 SDI MSb IN BIT6 - - - -1 LSb IN 74 73 Refer to Figure 20-1 for load conditions. TABLE 20-11: SPI MODE REQUIREMENTS (SLAVE MODE TIMING (CKE = 0) Param. No. 70 71 Symbol TssL2scH, TssL2scL TscH 73A SS↓ to SCK↓ or SCK↑ input TCY * Typ† Max Units — — ns ns Continuous 1.25TCY + 30 * — — Single Byte — — ns TscL SCK input low time (slave mode) Continuous 1.25TCY + 30 * — — ns Single Byte TdiV2scH, TdiV2scL TB2B 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 72A 73 Min SCK input high time (slave mode) 71A 72 Characteristic 40 40 — — ns 100 * — — ns 1.5TCY + 40 * — — ns 100 * — — ns 75 TscH2diL, TscL2diL TdoR SDO data output rise time — 10 25 * ns 76 TdoF SDO data output fall time — 10 25 * ns 77 TssH2doZ SS↑ to SDO output hi-impedance 10 * — 50 * ns 78 TscR SCK output rise time (master mode) — 10 25 * ns 79 TscF SCK output fall time (master mode) — 10 25 * ns 74 Conditions Note 1 Note 1 Note 1 TscH2doV, SDO data output valid after SCK edge — — 50 * ns TscL2doV 1.5TCY + 40 * — — ns TscH2ssH, SS ↑ after SCK edge 83 TscL2ssH * Characterized but not tested. † Data in "Typ" column is at 5V, 25˚C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: Specification 73A is only required if specifications 71A and 72A are used. 80 DS30289A-page 254 Preliminary 1998 Microchip Technology Inc. PIC17C7XX FIGURE 20-12: SPI SLAVE MODE TIMING (CKE = 1) 82 SS SCK (CKP = 0) 70 83 71 72 SCK (CKP = 1) 80 MSb SDO BIT6 - - - - - -1 LSb 75, 76 SDI MSb IN 77 BIT6 - - - -1 LSb IN 74 Refer to Figure 20-1 for load conditions. TABLE 20-12: SPI MODE REQUIREMENTS (SLAVE MODE, CKE = 1) Param. No. 70 71 Symbol TssL2scH, TssL2scL TscH 71A 72 TscL 72A 73A TB2B Characteristic Min SS↓ to SCK↓ or SCK↑ input TCY * Typ† Max Units — — ns ns SCK input high time (slave mode) Continuous 1.25TCY + 30 * — — Single Byte — — ns SCK input low time (slave mode) Continuous 1.25TCY + 30 * — — ns Single Byte 40 — — ns Note 1 1.5TCY + 40 * — — ns Note 1 100 * — — ns Last clock edge of Byte1 to the 1st clock edge of Byte2 Hold time of SDI data input to SCK edge 40 75 TscH2diL, TscL2diL TdoR SDO data output rise time — 10 25 * ns 76 TdoF SDO data output fall time — 10 25 * ns 77 TssH2doZ SS↑ to SDO output hi-impedance 10 * — 50 * ns 80 TscH2doV, SDO data output valid after SCK edge TscL2doV TssL2doV SDO data output valid after SS↓ edge — — 50 * ns — — 50 * ns 74 82 Conditions Note 1 1.5TCY + 40 * — — ns TscH2ssH, SS ↑ after SCK edge TscL2ssH * Characterized but not tested. † Data in "Typ" column is at 5V, 25˚C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: Specification 73A is only required if specifications 71A and 72A are used. 83 1998 Microchip Technology Inc. Preliminary DS30289A-page 255 PIC17C7XX FIGURE 20-13: I2C BUS START/STOP BITS TIMING SCL 93 91 90 92 SDA STOP Condition START Condition Note: Refer to Figure 20-1 for load conditions. TABLE 20-13: I2C BUS START/STOP BITS REQUIREMENTS Param. No. Sym 90 TSU:STA 91 92 93 Characteristic START condition Setup time THD:STA START condition Hold time TSU:STO STOP condition Setup time THD:STO STOP condition Hold time Min 100 kHz mode 400 kHz mode 2(TOSC)(BRG + 1) § 2(TOSC)(BRG + 1) § 1 MHz mode (1) 100 kHz mode 400 kHz mode 2(TOSC)(BRG + 1) § 2(TOSC)(BRG + 1) § 2(TOSC)(BRG + 1) § Typ Max Units Conditions — — — — — — — — ns Only relevant for repeated START condition — — ns After this period the first clock pulse is generated 1 MHz mode (1) 2(TOSC)(BRG + 1) § — — 100 kHz mode 400 kHz mode 1 MHz mode (1) 100 kHz mode 400 kHz mode 1 MHz mode (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) § — — ns ns § This specification ensured by design. Note 1: Maximum pin capacitance = 10 pF for all I2C pins. DS30289A-page 256 Preliminary 1998 Microchip Technology Inc. PIC17C7XX FIGURE 20-14: I2C BUS DATA TIMING 103 102 100 101 SCL 90 106 91 92 107 SDA In 110 109 109 SDA Out Note: Refer to Figure 20-1 for load conditions. TABLE 20-14: I2C BUS DATA REQUIREMENTS Param No. Sym Characteristic 100 THIGH Clock high time Min Max 100 kHz mode 2(TOSC)(BRG + 1) § — 400 kHz mode 2(TOSC)(BRG + 1) § — (1) 1 MHz mode 2(TOSC)(BRG + 1) § — TLOW Clock low time 100 kHz mode 2(TOSC)(BRG + 1) § — 101 400 kHz mode 2(TOSC)(BRG + 1) § — (1) 1 MHz mode 2(TOSC)(BRG + 1) § — TR SDA and SCL 100 kHz mode — 1000 * 102 rise time 400 kHz mode 20 + 0.1Cb * 300 * 1 MHz mode (1) — 300 * TF SDA and SCL 100 kHz mode — 300 * 103 fall time 400 kHz mode 20 + 0.1Cb * 300 * (1) 1 MHz mode — 100 * TSU:STA START condition 100 kHz mode 2(TOSC)(BRG + 1) § — 90 setup time 400 kHz mode 2(TOSC)(BRG + 1) § — 1 MHz mode (1) 2(TOSC)(BRG + 1) § — THD:STA START condition 100 kHz mode 2(TOSC)(BRG + 1) § — 91 hold time 400 kHz mode 2(TOSC)(BRG + 1) § — 1 MHz mode (1) 2(TOSC)(BRG + 1) § — THD:DAT Data input 100 kHz mode 0 — 106 hold time 400 kHz mode 0 0.9 * 1 MHz mode (1) TBD * — TSU:DAT Data input 100 kHz mode 250 * — 107 setup time 400 kHz mode 100 * — 1 MHz mode (1) TBD * — TSU:STO STOP condition 100 kHz mode 2(TOSC)(BRG + 1) § — 92 setup time 400 kHz mode 2(TOSC)(BRG + 1) § — (1) 1 MHz mode 2(TOSC)(BRG + 1) § — TAA Output valid 100 kHz mode — 3500 * 109 from clock 400 kHz mode — 1000 * 1 MHz mode (1) — — TBUF Bus free time 100 kHz mode 4.7 ‡ — 110 400 kHz mode 1.3 ‡ — TBD * — 1 MHz mode (1) D102 ‡ Cb Bus capacitive loading — 400 * * Characterized but not tested. § This specification ensured by design. ‡ These parameters are for design guidance only and are not tested, nor characterized. Note 1: 2: 3: 4: 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 ms ms ms pF Conditions Cb is specified to be from 10 to 400 pF Cb is specified to be from 10 to 400 pF Only relevant for repeated START condition After this period the first clock pulse is generated Note 2 Time the bus must be free before a new transmission can start Maximum pin capacitance = 10 pF for all I2C pins. 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. 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.) 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. 1998 Microchip Technology Inc. Preliminary DS30289A-page 257 PIC17C7XX FIGURE 20-15: USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING TX/CK pin 121 121 RX/DT pin 122 120 TABLE 20-15: USART SYNCHRONOUS TRANSMISSION REQUIREMENTS Param No. 120 Sym Characteristic TckH2dtV SYNC XMIT (MASTER & SLAVE) Clock high to data out valid Min Typ † PIC17CXXX — PIC17LCXXX — Max Units — 50 ns — 75 * ns ns Conditions 121 TckRF Clock out rise time and fall time (Master Mode) PIC17CXXX — — 25 PIC17LCXXX — — 40 * ns 122 TdtRF Data out rise time and fall time PIC17CXXX — — 25 ns PIC17LCXXX — — 40 * ns * † Characterized but not tested. Data in “Typ” column is at 5V, 25∞C unless otherwise stated. These parameters are for design guidance only and are not tested. FIGURE 20-16: USART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING TX/CK pin 125 RX/DT pin 126 TABLE 20-16: USART SYNCHRONOUS RECEIVE REQUIREMENTS Param No. † Min Typ † Sym Characteristic Max Units 125 TdtV2ckL SYNC RCV (MASTER & SLAVE) Data setup before CK↓ (DT setup time) 15 — — ns 126 TckL2dtl Data hold after CK↓ (DT hold time) 15 — — ns Conditions Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. DS30289A-page 258 Preliminary 1998 Microchip Technology Inc. PIC17C7XX FIGURE 20-17: USART ASYNCHRONOUS MODE START BIT DETECT Start bit RX (RX/DT pin) 121A x16 CLK Q2, Q4 CLK 120A 123A TABLE 20-17: USART ASYNCHRONOUS MODE START BIT DETECT REQUIREMENTS Param No. Sym Characteristic Min Typ† Max Units 120A TdtL2ckH Time to ensure that the RX pin is sampled low — — TCY § ns 121A TdtRF Data rise time and fall time Receive — — Note 1 ns Transmit — — 40 † ns — — TCY § ns 123A TckH2bckL Time from RX pin sampled low to first rising edge of x16 clock Conditions † These parameters are for design guidance only and are not tested. § This specification ensured by design. Note 1: Schmitt trigger will determine logic level. FIGURE 20-18: USART ASYNCHRONOUS RECEIVE SAMPLING WAVEFORM Start bit RX (RX/DT pin) Bit0 Baud CLK for all but start bit baud CLK x16 CLK 1 2 3 4 5 6 125A 7 8 9 10 11 126A 12 13 14 15 16 1 2 3 Samples TABLE 20-18: USART ASYNCHRONOUS RECEIVE SAMPLING REQUIREMENTS Param No. Sym Characteristic Min Typ † Max Units 125A TdtL2ckH Setup time of RX pin to first data sampled TCY § — — ns 126A TdtL2ckH Hold time of RX pin from last data sampled TCY § — — ns Conditions § This specification ensured by design. 1998 Microchip Technology Inc. Preliminary DS30289A-page 259 PIC17C7XX TABLE 20-19: A/D CONVERTER CHARACTERISTICS Param. No. Sym A01 NR EABS A02 EIL A03 EDL A04 EFS A05 EOFF A06 A10 — A20 VREF Characteristic Min Typ† Max Units — — 10 bit VREF+ = VDD = 5.12V, VSS ≤ VAIN ≤ VREF+ — — 10* bit (VREF+ — VREF-) ≥ 3.0V, VREF- ≤ VAIN ≤ VREF+ — — < ±1 LSb VREF+ = VDD = 5.12V, VSS ≤ VAIN ≤ VREF+ — — < ±1* LSb (VREF+ — VREF-) ≥ 3.0V, VREF- ≤ VAIN ≤ VREF+ — — < ±1 LSb VREF+ = VDD = 5.12V, VSS ≤ VAIN ≤ VREF+ — — < ±1* LSb (VREF+ — VREF-) ≥ 3.0V, VREF- ≤ VAIN ≤ VREF+ — — < ±1 LSb VREF+ = VDD = 5.12V, VSS ≤ VAIN ≤ VREF+ — — < ±1* LSb (VREF+ — VREF-) ≥ 3.0V, VREF- ≤ VAIN ≤ VREF+ — — < ±1 LSb VREF+ = VDD = 5.12V, VSS ≤ VAIN ≤ VREF+ — — < ±1* LSb (VREF+ — VREF-) ≥ 3.0V, VREF- ≤ VAIN ≤ VREF+ — — < ±1 LSb VREF+ = VDD = 5.12V, VSS ≤ VAIN ≤ VREF+ — — < ±1* LSb (VREF+ — VREF-) ≥ 3.0V, VREF- ≤ VAIN ≤ VREF+ Monotonicity — guaranteed — — VSS ≤ VAIN ≤ VREF Reference voltage (VREF+ — VREF-) 0V — — V VREF delta when changing voltage levels on VREF inputs. 3V * — — V Absolute minimum electrical spec. To ensure 10-bit accuracy Resolution Absolute error Integral linearity error Differential linearity error Full scale error Offset error A20A Conditions A21 VREF+ Reference voltage High AVSS + 3.0V — AVDD + 0.3V V A22 VREF- Reference voltage Low AVSS - 0.3V — AVDD 3.0V V A25 VAIN Analog input voltage AVSS - 0.3V — VREF + 0.3V V A30 ZAIN Recommended impedance of analog voltage source — — 10.0 kΩ A40 IAD A/D conversion current (VDD) PIC17CXXX — 180 — µA PIC17LCXXX — 90 — µA 10 — 1000 µA During VAIN acquisition. Based on differential of VHOLD to VAIN. — — 10 µA During A/D conversion cycle IREF A50 VREF input current (Note 2) Average current consumption when A/D is on. (Note 1) * † These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. 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. DS30289A-page 260 Preliminary 1998 Microchip Technology Inc. PIC17C7XX FIGURE 20-19: A/D CONVERSION TIMING BSF ADCON0, GO 1 TCY (TOSC/2) (1) 131 Q4 130 A/D CLK 132 9 A/D DATA 8 7 ... ... 2 1 0 NEW_DATA OLD_DATA ADRES ADIF GO DONE SAMPLING STOPPED 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 20-20: A/D CONVERSION REQUIREMENTS Param. No. Sym Characteristic 130 TAD A/D clock period Min Typ† Max Units PIC17CXXX 1.6 — — µs PIC17LCXXX 3.0 — — µs TOSC based, VREF full range PIC17CXXX 2.0 * 4.0 6.0 * µs A/D RC Mode PIC17LCXXX 3.0 * 6.0 9.0 * µs A/D RC Mode 11 § — 12 § TAD (Note 2) 20 — µs 10 * — — µs 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). — Tosc/2 § — — 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. 131 TCNV Conversion time (not including acquisition time) (Note 1) 132 TACQ Acquisition time 134 * † § Note 1: TGO Q4 to ADCLK start Conditions TOSC based, VREF ≥ 3.0V These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25°C unless otherwise stated. Parameters are for design guidance only and are not tested. This specification ensured by design. ADRES register may be read on the following TCY cycle. 1998 Microchip Technology Inc. Preliminary DS30289A-page 261 PIC17C7XX FIGURE 20-20: MEMORY INTERFACE WRITE TIMING Q1 Q2 Q3 Q4 Q2 Q1 OSC1 ALE OE 151 WR 150 AD<15:0> 154 data out addr out addr out 152 153 TABLE 20-21: MEMORY INTERFACE WRITE REQUIREMENTS Param. No. 150 151 Sym Characteristic Min Typ† Max TadV2alL AD<15:0> (address) valid to PIC17CXXX 0.25TCY - 10 — — ALE↓ (address setup time) PIC17LCXXX 0.25TCY - 10* — — ns TalL2adI ALE↓ to address out invalid (address hold time) 152 TadV2wrL Data out valid to WR↓ TwrH2adI WR↑ to data out invalid * † § 0 — — 0* — — PIC17CXXX 0.25TCY - 40 — — PIC17LCXXX 0.25TCY - 40* — — ns PIC17CXXX — 0.25TCY§ — PIC17LCXXX — 0.25TCY§ — PIC17CXXX — 0.25TCY§ — PIC17LCXXX — 0.25TCY§ — ns (data hold time) 154 PIC17CXXX PIC17LCXXX ns (data setup time) 153 Units Conditions TwrL WR pulse width ns These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. This specification ensured by design. DS30289A-page 262 Preliminary 1998 Microchip Technology Inc. PIC17C7XX FIGURE 20-21: MEMORY INTERFACE READ TIMING Q1 Q2 Q3 Q4 Q1 Q2 OSC1 166 ALE 164 168 160 OE 165 AD<15:0> Addr out 162 150 WR 161 Data in Addr out 151 163 167 '1' '1' TABLE 20-22: MEMORY INTERFACE READ REQUIREMENTS Param. No. Sym 150 TadV2alL Characteristic AD15:AD0 (address) valid to TalL2adI ALE↓ to address out invalid (address hold time) 160 TadZ2oeL AD15:AD0 hi-impedance to 162 ToeH2adD OE↑ to AD15:AD0 driven TadV2oeH Data in valid before OE↑ 165 166 167 168 ToeH2adI OE↑to data in invalid § — — PIC17CXXX 5* — — PIC17LCXXX 5* — — PIC17CXXX 0* — — PIC17LCXXX 0* — — PIC17CXXX 0.25TCY - 15 — — PIC17LCXXX 0.25TCY - 15* — — ns PIC17CXXX 35 — — PIC17LCXXX 45* — — PIC17CXXX 0 — — PIC17LCXXX 0* — — ns TalH ToeL ALE pulse width OE pulse width PIC17CXXX — 0.25TCY § — PIC17LCXXX — 0.25TCY § — PIC17CXXX 0.5TCY - 35 § — — PIC17LCXXX 0.5TCY - 35 § — — ns ns TalH2alH Tacc Toe ALE↑ to ALE↑(cycle time) Address access time Output enable access time PIC17CXXX — TCY § — PIC17LCXXX — TCY § — PIC17CXXX — — 0.75TCY - 30 PIC17LCXXX — — 0.75TCY 45* PIC17CXXX — — 0.5TCY - 45 PIC17LCXXX — — 0.5TCY - 75* ns ns ns (OE low to Data Valid) * † PIC17LCXXX 0.25TCY - 10* Units Conditions ns (data hold time) 164 — ns (data setup time) 163 Max — ns OE↓ 161 Typ† ns ALE↓ (address setup time) 151 Min 0.25TCY - 10 PIC17CXXX These parameters are characterized but not tested. Data in “Typ” column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. This specification ensured by design. 1998 Microchip Technology Inc. Preliminary DS30289A-page 263 PIC17C7XX NOTES: DS30289A-page 264 Preliminary 1998 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. "Typical" represents the mean of the distribution while "max" or "min" represents (mean + 3σ) and (mean - 3σ) respectively where σ is standard deviation. TABLE 21-1: PIN CAPACITANCE PER PACKAGE TYPE Typical Capacitance (pF) Pin Name 68-pin PLCC 64-pin TQFP 10 20 10 20 All pins, except MCLR, VDD, and VSS MCLR pin FIGURE 21-1: TYPICAL RC OSCILLATOR FREQUENCY vs. TEMPERATURE FOSC FOSC (25°C) Frequency normalized to +25°C 1.10 Rext ≥ 10 kΩ Cext = 100 pF 1.08 1.06 1.04 1.02 1.00 VDD = 5.5V 0.98 0.96 0.94 VDD = 3.5V 0.92 0.90 0 10 20 25 30 40 50 60 70 T(°C) 1998 Microchip Technology Inc. Preliminary DS30289A-page 265 PIC17C7XX FIGURE 21-2: TYPICAL RC OSCILLATOR FREQUENCY vs. VDD 4.0 3.5 R = 10k FOSC (MHz) 3.0 2.5 2.0 1.5 Cext = 22 pF, T = 25°C 1.0 0.5 R = 100k 0.0 4.0 4.5 5.0 5.5 6.0 6.5 6.0 6.5 VDD (Volts) FIGURE 21-3: TYPICAL RC OSCILLATOR FREQUENCY vs. VDD 4.0 3.5 R = 3.3k FOSC (MHz) 3.0 2.5 R = 5.1k 2.0 1.5 R = 10k 1.0 Cext = 100 pF, T = 25°C 0.5 R = 100k 0.0 4.0 4.5 5.0 5.5 VDD (Volts) DS30289A-page 266 Preliminary 1998 Microchip Technology Inc. PIC17C7XX FIGURE 21-4: TYPICAL RC OSCILLATOR FREQUENCY vs. VDD 2.0 1.8 1.6 1.4 R = 3.3k FOSC (MHz) 1.2 R = 5.1k 1.0 0.8 R = 10k 0.6 0.4 Cext = 300 pF, T = 25°C 0.2 R = 160k 0.0 4.0 4.5 5.0 5.5 6.0 6.5 VDD (Volts) TABLE 21-2: RC OSCILLATOR FREQUENCIES Cext Rext 22 pF 10k 100k 3.3k 5.1k 10k 100k 3.3k 5.1k 10k 160k 100 pF 300 pF 1998 Microchip Technology Inc. Average Fosc @ 5V, 25°C 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 Preliminary ± 12% ± 13% ± 10% ± 14% ± 17% ± 10% ± 14% ± 12% ± 16% ± 18% DS30289A-page 267 PIC17C7XX FIGURE 21-5: TRANSCONDUCTANCE (gm) OF LF OSCILLATOR vs. VDD 500 450 400 350 Max @ -40°C gm(µA/V) 300 Typ @ 25°C 250 200 150 Min @ 85°C 100 50 0 2.5 3.0 3.5 4.0 4.5 5.5 5.0 6.0 VDD (Volts) FIGURE 21-6: TRANSCONDUCTANCE (gm) OF XT OSCILLATOR vs. VDD 20 18 Max @ -40°C 16 14 Typ @ 25°C gm(mA/V) 12 10 8 6 Min @ 85°C 4 2 0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 VDD (Volts) DS30289A-page 268 Preliminary 1998 Microchip Technology Inc. PIC17C7XX FIGURE 21-7: TYPICAL IDD vs. FREQUENCY (EXTERNAL CLOCK 25°C) 100000 IDD (µA) 10000 1000 7.0V 100 6.5V 6.0V 5.5V 5.0V 4.5V 4.0V 10 10k 100k 1M External Clock Frequency (Hz) 10M 100M FIGURE 21-8: MAXIMUM IDD vs. FREQUENCY (EXTERNAL CLOCK 125°C TO -40°C) 100000 IDD (µA) 10000 1000 7.0V 6.5V 6.0V 5.5V 5.0V 4.5V 4.0V 100 10k 100k 1M 10M 100M External Clock Frequency (Hz) 1998 Microchip Technology Inc. Preliminary DS30289A-page 269 PIC17C7XX FIGURE 21-9: TYPICAL IPD vs. VDD WATCHDOG DISABLED 25°C 12 10 IPD(nA) 8 6 4 2 0 4.0 4.5 5.0 5.5 6.5 6.0 7.0 VDD (Volts) IPD(nA) FIGURE 21-10: MAXIMUM IPD vs. VDD WATCHDOG DISABLED 1900 1800 1700 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 Temp. = 85°C Temp. = 70°C Temp. = 0°C 4.0 4.5 5.0 5.5 6.0 Temp. = -40°C 6.5 7.0 VDD (Volts) DS30289A-page 270 Preliminary 1998 Microchip Technology Inc. PIC17C7XX FIGURE 21-11: TYPICAL IPD vs. VDD WATCHDOG ENABLED 25°C 30 25 IPD(µA) 20 15 10 5 0 4.0 4.5 5.0 5.5 6.5 6.0 7.0 VDD (Volts) FIGURE 21-12: MAXIMUM IPD vs. VDD WATCHDOG ENABLED 60 50 -40°C 70°C IPD(µA) 40 0°C 85°C 30 20 10 0 4.0 4.5 5.0 5.5 6.0 6.5 7.0 VDD (Volts) 1998 Microchip Technology Inc. Preliminary DS30289A-page 271 PIC17C7XX FIGURE 21-13: WDT TIMER TIME-OUT PERIOD vs. VDD 30 25 Max. 85°C WDT Period (ms) 20 Max. 70°C Min. 0°C 15 Typ. 25°C 10 Min. -40°C 5 0 4.0 4.5 5.0 5.5 6.0 6.5 7.0 2.5 3.0 VDD (Volts) FIGURE 21-14: IOH vs. VOH, VDD = 3V 0 -2 IOH(mA) -4 -6 Min @ 85°C -8 Typ @ 25°C -10 -12 -14 Max @ -40°C -16 -18 0.0 0.5 1.0 1.5 2.0 VOH (Volts) DS30289A-page 272 Preliminary 1998 Microchip Technology Inc. PIC17C7XX FIGURE 21-15: IOH vs. VOH, VDD = 5V 0 -5 -10 IOH(mA) Min @ 85°C -15 -20 Max @ -40°C -25 Typ @ 25°C -30 -35 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 VOH (Volts) FIGURE 21-16: IOL vs. VOL, VDD = 3V 30 Max. -40°C 25 Typ. 25°C IOL(mA) 20 15 Min. +85°C 10 5 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 VOL (Volts) 1998 Microchip Technology Inc. Preliminary DS30289A-page 273 PIC17C7XX FIGURE 21-17: IOL vs. VOL, VDD = 5V 90 80 70 IOL(mA) Max @ -40°C Typ @ 25°C 60 50 Min @ +85°C 40 30 20 10 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 VOL (Volts) FIGURE 21-18: VTH (INPUT THRESHOLD VOLTAGE) OF I/O PINS (TTL) VS. VDD 2.0 1.8 Max (-40°C to +85°C) 1.6 VTH(Volts) Typ @ 25°C 1.4 1.2 1.0 Min (-40°C to +85°C) 0.8 0.6 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 VDD (Volts) DS30289A-page 274 Preliminary 1998 Microchip Technology Inc. PIC17C7XX FIGURE 21-19: VIH, VIL of I/O PINS (SCHMITT TRIGGER) VS. VDD 5.0 VIH, max (-40°C to +85°C) 4.5 VIH, typ (25°C) 4.0 VIH, min (-40°C to +85°C) VIH, VIL(Volts) 3.5 3.0 VIL, max (-40°C to +85°C) 2.5 VIL, typ (25°C) VIL, min (-40°C to +85°C) 2.0 1.5 1.0 0.5 0.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 VDD (Volts) FIGURE 21-20: VTH (INPUT THRESHOLD VOLTAGE) OF OSC1 INPUT (IN XT AND LF MODES) vs. VDD 3.4 3.2 Typ (25°C) 3.0 Max (-40°C to +85°C) VTH,(Volts) 2.8 2.6 2.4 2.2 2.0 Min (-40°C to +85°C) 1.8 1.6 1.4 1.2 1.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 VDD (Volts) 1998 Microchip Technology Inc. Preliminary DS30289A-page 275 PIC17C7XX NOTES: DS30289A-page 276 Preliminary 1998 Microchip Technology Inc. PIC17C7XX 22.0 PACKAGING INFORMATION Package Type: K04-085 64-Lead Plastic Thin Quad Flatpack (PT) 10x10x1 mm Body, 1.0/0.1 mm Lead Form E1 E # leads = n1 p D D1 2 1 B n X x 45° L c φ R1 β Units Dimension Limits Pitch Number of Pins Pins along Width Overall Pack. Height Shoulder Height Standoff Shoulder Radius Gull Wing Radius Foot Length Foot Angle Radius Centerline Lead Thickness Lower Lead Width Outside Tip Length Outside Tip Width Molded Pack. Length Molded Pack. Width Pin 1 Corner Chamfer Mold Draft Angle Top Mold Draft Angle Bottom A1 L1 A2 0.039 0.015 0.002 0.003 0.003 0.005 0 0.003 0.004 0.007 0.463 0.463 0.390 0.390 0.025 5 5 INCHES NOM 0.020 64 16 0.043 0.025 0.004 0.003 0.006 0.012 3.5 0.008 0.006 0.009 0.472 0.472 0.394 0.394 0.035 10 12 MIN p n n1 A A1 A2 R1 R2 L φ L1 c B† D1 E1 D‡ E‡ X α β α A R2 MAX 0.047 0.035 0.006 0.010 0.008 0.015 7 0.013 0.008 0.011 0.482 0.482 0.398 0.398 0.045 15 15 MILLIMETERS* NOM MAX 0.50 64 16 1.10 1.20 1.00 0.38 0.64 0.89 0.10 0.15 0.05 0.08 0.25 0.08 0.14 0.20 0.08 0.38 0.13 0.30 0 3.5 7 0.08 0.20 0.33 0.09 0.15 0.20 0.27 0.17 0.22 12.25 11.75 12.00 12.25 11.75 12.00 9.90 10.10 10.00 9.90 10.10 10.00 0.64 0.89 1.14 5 10 15 5 12 15 MIN * Controlling Parameter. † Dimension “B” does not include dam-bar protrusions. Dam-bar protrusions shall not exceed 0.003” (0.076 mm) per side or 0.006” (0.152 mm) more than dimension “B.” ‡ Dimensions “D” and “E” do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.010” (0.254 mm) per side or 0.020” (0.508 mm) more than dimensions “D” or “E.” 1998 Microchip Technology Inc. DS30289A-page 277 PIC17C7XX Package Type: K04-049 68-Lead Plastic Leaded Chip Carrier (L) – Square E1 E # leads = n1 D D1 α n 12 CH1 x 45° CH2 x 45° A3 A1 R1 L 32° c R2 A B1 B A2 β E2 Units Dimension Limits Number of Pins Pitch Overall Pack. Height Shoulder Height Standoff Side 1 Chamfer Dim. Corner Chamfer (1) Corner Chamfer (other) Overall Pack. Width Overall Pack. Length Molded Pack. Width Molded Pack. Length Footprint Width Footprint Length Pins along Width Lead Thickness Upper Lead Width Lower Lead Width Upper Lead Length Shoulder Inside Radius J-Bend Inside Radius Mold Draft Angle Top Mold Draft Angle Bottom p D2 INCHES* NOM 68 0.050 0.165 0.175 0.095 0.103 0.017 0.025 0.021 0.026 0.035 0.045 0.000 0.005 0.985 0.990 0.985 0.990 0.950 0.954 0.950 0.954 0.910 0.920 0.910 0.920 17 0.008 0.010 0.029 0.026 0.015 0.018 0.050 0.058 0.003 0.005 0.015 0.025 0 5 0 5 MIN n e1 A A1 A2 A3 CH1 CH2 E1 D1 E‡ D‡ E2 D2 n1 c B1† B L R1 R2 α β MAX 0.185 0.110 0.032 0.031 0.055 0.010 0.995 0.995 0.958 0.958 0.930 0.930 0.012 0.031 0.021 0.065 0.010 0.035 10 10 MILLIMETERS NOM MAX 68 1.27 4.19 4.45 4.70 2.41 2.60 2.79 0.43 0.81 0.62 0.53 0.66 0.79 0.89 1.14 1.40 0.00 0.25 0.13 25.02 25.15 25.27 25.02 25.15 25.27 24.13 24.23 24.33 24.13 24.23 24.33 23.11 23.37 23.62 23.37 23.11 23.62 17 0.20 0.25 0.30 0.66 0.72 0.79 0.38 0.46 0.53 1.27 1.46 1.65 0.08 0.13 0.25 0.38 0.64 0.89 0 5 10 0 5 10 MIN * Controlling Parameter. † Dimension “B1” does not include dam-bar protrusions. Dam-bar protrusions shall not exceed 0.003” (0.076 mm) per side or 0.006” (0.152 mm) more than dimension “B1.” ‡ Dimensions “D” and “E” do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.010" (0.254 mm) per side or 0.020" (0.508 mm) more than dimensions “D” or “E.” DS30289A-page 278 1998 Microchip Technology Inc. PIC17C7XX Package Type: K04-093 84-Lead Plastic Leaded Chip Carrier (L) – Square E1 E # leads = n1 D CH2 x 45° n12 D1 α CH1 x 45° A3 R1 A1 c R2 B1 β n p A A1 A2 A3 CH1 CH2 E1 D1 E‡ D‡ E2 D2 n1 c B1† B L R1 R2 α β INCHES* MIN NOM 84 0.050 0.173 0.165 0.105 0.090 0.025 0.020 0.045 0.042 0.045 0.042 0.015 0.010 1.190 1.185 1.190 1.185 1.154 1.150 1.154 1.150 1.110 1.095 1.095 1.110 21 0.008 0.010 0.028 0.023 0.018 0.013 0.058 0.050 0.003 0.005 0.022 0.027 0 5 0 5 L p B A2 E2 Units Dimension Limits Number of Pins Pitch Overall Pack. Height Shoulder Height Standoff Side 1 Chamfer Dim. Corner Chamfer (1) Corner Chamfer(other) Overall Pack. Width Overall Pack. Length Molded Pack. Width Molded Pack. Length Footprint Width Footprint Length Pins along Width Lead Thickness Upper Lead Width Lower Lead Width Upper Lead Length Shoulder Inside Radius J-Bend Inside Radius Mold Draft Angle Top Mold Draft Angle Bottom A 45° D2 MAX 0.180 0.120 0.030 0.048 0.048 0.020 1.195 1.195 1.158 1.158 1.125 1.125 0.012 0.033 0.023 0.065 0.010 0.032 10 10 MILLIMETERS NOM MAX 84 1.27 4.38 4.19 4.57 2.67 2.29 3.05 0.64 0.51 0.76 1.14 1.07 1.22 1.14 1.07 1.22 0.38 0.25 0.51 30.23 30.10 30.35 30.23 30.10 30.35 29.31 29.21 29.41 29.31 29.21 29.41 28.19 27.81 28.58 28.19 27.81 28.58 21 0.25 0.20 0.30 0.84 0.58 0.71 0.58 0.33 0.46 1.65 1.27 1.46 0.13 0.25 0.08 0.69 0.81 0.56 10 0 5 10 0 5 MIN * Controlling Parameter. † Dimension “B1” does not include dam-bar protrusions. Dam-bar protrusions shall not exceed 0.003” (0.076 mm) per side or 0.006” (0.152 mm) more than dimension “B1.” ‡ Dimensions “D” and “E” do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.010” (0.254 mm) per side or 0.020” (0.508 mm) more than dimensions “D” or “E.” 1998 Microchip Technology Inc. DS30289A-page 279 PIC17C7XX Package Type: K04-092 80-Lead Plastic Thin Quad Flatpack (PT) 12x12x1 mm Body, 1.0/0.1 mm Lead Form E1 E # lead s = n1 p D D1 2 1 B n X x 45° L α A R2 c φ L1 R1 β Units Dimension Limits Pitch Number of Pins Pins along Width Overall Pack. Height Shoulder Height Standoff Shoulder Radius Gull Wing Radius Foot Length Foot Angle Radius Centerline Lead Thickness Lower Lead Width Outside Tip Length Outside Tip Width Molded Pack. Length Molded Pack. Width Pin 1 Corner Chamfer Mold Draft Angle Top Mold Draft Angle Bottom MIN p n n1 A A1 A2 R1 R2 L φ L1 c B† D1 E1 D‡ E‡ X α β 0.039 0.015 0.002 0.003 0.003 0.005 0 0.003 0.004 0.007 0.542 0.542 0.462 0.462 0.025 5 5 A1 A2 INCHES NOM 0.020 80 20 0.043 0.025 0.004 0.003 0.006 0.012 3.5 0.008 0.006 0.009 0.551 0.551 0.472 0.472 0.035 10 12 MAX 0.047 0.035 0.006 0.010 0.008 0.015 7 0.013 0.008 0.011 0.561 0.561 0.482 0.482 0.045 15 15 MILLIMETERS* MAX NOM 0.50 80 20 1.20 1.00 1.10 0.89 0.38 0.64 0.15 0.05 0.10 0.25 0.08 0.08 0.20 0.08 0.14 0.38 0.13 0.30 7 0 3.5 0.33 0.08 0.20 0.20 0.09 0.15 0.27 0.17 0.22 14.00 13.77 14.25 14.00 13.77 14.25 12.00 11.73 12.24 11.73 12.00 12.24 0.64 0.89 1.14 5 10 15 5 12 15 MIN * Controlling Parameter. † Dimension “B” does not include dam-bar protrusions. Dam-bar protrusions shall not exceed 0.003” (0.076 mm) per side or 0.006” (0.152 mm) more than dimension “B.” ‡ Dimensions “D” and “E” do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.010” (0.254 mm) per side or 0.020” (0.508 mm) more than dimensions “D” or “E.” DS30289A-page 280 1998 Microchip Technology Inc. PIC17C7XX 22.1 Package Marking Information 64-Lead TQFP Example MMMMMMMMMM MMMMMMMMMM MMMMMMMMMM AABBCDE 68/84-Lead CERQUAD Windowed MMMMMMMMMMMMMMMMM AABBCDE 68/84-Lead PLCC MMMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMM MMMMMMMMMMMMMMMMM 9817CAE Example PIC17C756-04/CL 9850CAE Example PIC17C756A -08/L AABBCDE 9848CAE 80-Lead TQFP Example MMMMMMMMMMMM MMMMMMMMMMMM AABBCDE Legend: MM...M XX...X AA BB C D E Note: * PIC17C752 -08I/PT PIC17C752 -08I/PT 9817CAE Microchip part number information Customer specific information* Year code (last 2 digits of calendar year) Week code (week of January 1 is week ‘01’) Facility code of the plant at which wafer is manufactured O = Outside Vendor C = 5” Line S = 6” Line H = 8” Line Mask revision number Assembly code of the plant or country of origin in which part was assembled 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. 1998 Microchip Technology Inc. DS30289A-page 281 PIC17C7XX NOTES: DS30289A-page 282 1998 Microchip Technology Inc. PIC17C7XX APPENDIX A: MODIFICATIONS APPENDIX B: COMPATIBILITY The following is the list of modifications over the PIC16CXX microcontroller family: To convert code written for PIC16CXXX to PIC17CXXX, the user should take the following steps: 1. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 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 have been removed. 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 replaces 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 Power-Up 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). Configuration 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 a VREF+ and VREF-. 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. 1998 Microchip Technology Inc. 2. 3. 4. 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: 5. 6. 7. 8. 9. If REG1 and REG2 are both at addresses greater then 20h, two instructions are required. MOVFP REG1, WREG ; MOVPF WREG, REG2 ; Ensure that all bit names and register names are updated to new data memory map locations. Verify data memory banking. Verify mode of operation for indirect addressing. Verify peripheral routines for compatibility. Weak pull-ups are enabled on reset. Upgrading from PIC17C42 Devices To convert code from the PIC17C42 to all the other PIC17CXXX devices, the user should take the following steps. 1. 2. 3. 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. DS30289A-page 283 PIC17C7XX APPENDIX C: WHAT’S NEW APPENDIX D: WHAT’S CHANGED This is a new Data Sheet for the Following Devices: This is a new Data Sheet. The following are changes from the PIC17C75X data Sheet: • • • • PIC17C752 PIC17C756A PIC17C762 PIC17C766 This Data Sheet is based of the PIC17C75X Data Sheet (DS30246A) Updated the Master SSP section. Updated the 10-bit A/D section. Minor corrections and updates throughout the data sheet. PIC17C752 Data Memory upgraded to 678 bytes Port initialization values clarified Extended voltage specification for external memory interface added Some Electrical Specifications changed due to new process technology Clarified operation of Table Reads / Table Writes with external memory (for microprocessor and extended microcontroller modes). Added waveforms / requirements for USART Asynchronous mode in Electrical specifications. Clarification to Master SSP Baud Rate Generator timing figure and associated text. Added example code MPLAB-C17 ’C’ code. for I2C operation using Updated Packaging Diagrams / Tables DS30289A-page 284 1998 Microchip Technology Inc. PIC17C7XX APPENDIX E: I 2C OVERVIEW This section provides an overview of the Inter-Integrated Circuit (I 2C) bus, with Section 15.2 discussing the operation of the SSP module in I 2C mode. The I 2C bus is a two-wire serial interface developed by the Philips Corporation. The original specification, or standard mode, was for data transfers of up to 100 Kbps. This device will communicate with fast mode devices if attached to the same bus. The I 2C interface employs a comprehensive protocol to ensure reliable transmission and reception of data. When transmitting data, one device is the “master” which initiates transfer on the bus and generates the clock signals to permit that transfer, while the other device(s) acts as the “slave.” All portions of the slave protocol are implemented in the SSP module’s hardware, including general call support. Table E-1 defines some of the I 2C bus terminology. For additional information on the I 2C interface specification, refer to the Philips document “The I 2C bus and how to use it.” #939839340011, which can be obtained from the Philips Corporation. In the I 2C interface protocol each device has an address. When a master wishes to initiate a data transfer, it first transmits the address of the device that it wishes to “talk” to. All devices “listen” to see if this is their address. Within this address, a bit specifies if the master wishes to read-from/write-to the slave device. The master and slave are always in opposite modes (transmitter/receiver) of operation during a data transfer. That is they can be thought of as operating in either of these two relations: External pull-up resistors are used to ensure a high level when no device is pulling the line down. The number of devices that may be attached to the I 2C bus is limited only by the maximum bus loading specification of 400 pF. E.1 Initiating and Terminating Data Transfer During times of no data transfer (idle time), both the clock line (SCL) and the data line (SDA) are pulled high through the external pull-up resistors. The START and STOP conditions determine the start and stop of data transmission. The START condition is defined as a high to low transition of the SDA when the SCL is high. The STOP condition is defined as a low to high transition of the SDA when the SCL is high. Figure E-1 shows the START and STOP conditions. The master generates these conditions for starting and terminating data transfer. Due to the definition of the START and STOP conditions, when data is being transmitted, the SDA line can only change state when the SCL line is low. FIGURE E-1: START AND STOP CONDITIONS SDA SCL S Start Condition P Change of Data Allowed Change of Data Allowed Stop Condition • Master-transmitter and Slave-receiver • Slave-transmitter and Master-receiver In both cases the master generates the clock signal. The output stages of the clock (SCL) and data (SDA) lines must have an open-drain or open-collector in order to perform the wired-AND function of the bus. TABLE E-1: I2C BUS TERMINOLOGY Term Description Transmitter The device that sends the data to the bus. Receiver The device that receives the data from the bus. Master The device which initiates the transfer, generates the clock and terminates the transfer. Slave The device addressed by a master. Multi-master More than one master device in a system. These masters can attempt to control the bus at the same time without corrupting the message. Arbitration Procedure that ensures that only one of the master devices will control the bus. This ensure that the transfer data does not get corrupted. Synchronization Procedure where the clock signals of two or more devices are synchronized. 1998 Microchip Technology Inc. DS30289A-page 285 PIC17C7XX ADDRESSING I 2C DEVICES E.2 FIGURE E-4: There are two address formats. The simplest is the 7-bit address format with a R/W bit (Figure E-2). The more complex is the 10-bit address with a R/W bit (Figure E-3). For 10-bit address format, two bytes must be transmitted with the first five bits specifying this to be a 10-bit address. FIGURE E-2: Data Output by Receiver 9 8 2 1 S Start Condition Clock Pulse for Acknowledgment If the master is receiving the data (master-receiver), it generates an acknowledge signal for each received byte of data, except for the last byte. To signal the end of data to the slave-transmitter, the master does not generate an acknowledge (not acknowledge). The slave then releases the SDA line so the master can generate the STOP condition. The master can also generate the STOP condition during the acknowledge pulse for valid termination of data transfer. Sent by Slave Start Condition Read/Write pulse Acknowledge I2C 10-BIT ADDRESS FORMAT FIGURE E-3: If the slave needs to delay the transmission of the next byte, holding the SCL line low will force the master into a wait state. Data transfer continues when the slave releases the SCL line. This allows the slave to move the received data or fetch the data it needs to transfer before allowing the clock to start. This wait state technique can also be implemented at the bit level, Figure E-5. The slave will inherently stretch the clock, when it is a transmitter, but will not when it is a receiver. The slave will have to clear the CKP bit to enable clock stretching when it is a receiver. S 1 1 1 1 0 A9 A8 R/W ACK A7 A6 A5 A4 A3 A2 A1 A0 ACK sent by slave = 0 for write E.3 acknowledge SCL from Master LSb slave address S R/W ACK not acknowledge R/W ACK S S R/W ACK Data Output by Transmitter 7-BIT ADDRESS FORMAT MSb SLAVE-RECEIVER ACKNOWLEDGE - Start Condition - Read/Write Pulse - Acknowledge Transfer Acknowledge All data must be transmitted per byte, with no limit to the number of bytes transmitted per data transfer. After each byte, the slave-receiver generates an acknowledge bit (ACK) (Figure E-4). When a slave-receiver doesn’t acknowledge the slave address or received data, the master must abort the transfer. The slave must leave SDA high so that the master can generate the STOP condition (Figure E-1). FIGURE E-5: DATA TRANSFER WAIT STATE SDA MSB acknowledgment signal from receiver byte complete interrupt with receiver acknowledgment signal from receiver clock line held low while interrupts are serviced SCL S Start Condition DS30289A-page 286 1 2 Address 7 8 R/W 9 ACK 1 Wait State 2 Data 3•8 9 ACK P Stop Condition 1998 Microchip Technology Inc. PIC17C7XX SCL is high), but occurs after a data transfer acknowledge pulse (not the bus-free state). This allows a master to send “commands” to the slave and then receive the requested information or to address a different slave device. This sequence is shown in Figure E-8. Figure E-6 and Figure E-7 show Master-transmitter and Master-receiver data transfer sequences. When a master does not wish to relinquish the bus (by generating a STOP condition), a repeated START condition (Sr) must be generated. This condition is identical to the start condition (SDA goes high-to-low while FIGURE E-6: MASTER-TRANSMITTER SEQUENCE For 10-bit address: S Slave Address R/W A1 Slave Address A2 Second byte First 7 bits For 7-bit address: S Slave Address R/W A Data A Data A/A P '0' (write) data transferred (n bytes - acknowledge) A master transmitter addresses a slave receiver with a 7-bit address. The transfer direction is not changed. From master to slave From slave to master FIGURE E-7: (write) Data A A = acknowledge (SDA low) A = not acknowledge (SDA high) S = Start Condition P = Stop Condition A master transmitter addresses a slave receiver with a 10-bit address. MASTER-RECEIVER SEQUENCE For 10-bit address: For 7-bit address: S Slave Address R/W A1 Slave Address A2 Second byte First 7 bits S Slave Address R/W A Data A Data A P '1' (read) data transferred (n bytes - acknowledge) A master reads a slave immediately after the first byte. From master to slave From slave to master FIGURE E-8: Data A/A P (write) A = acknowledge (SDA low) A = not acknowledge (SDA high) S = Start Condition P = Stop Condition Sr Slave Address R/W A3 Data A First 7 bits Data A P (read) A master transmitter addresses a slave receiver with a 10-bit address. COMBINED FORMAT (read or write) (n bytes + acknowledge) S Slave Address R/W A Data A/A Sr Slave Address R/W A Data A/A P (read) Sr = repeated Start Condition (write) Direction of transfer may change at this point Transfer direction of data and acknowledgment bits depends on R/W bits. Combined format: Sr Slave Address R/W A Slave Address A Data A First 7 bits Second byte Data A/A Sr Slave Address R/W A Data A First 7 bits Data A P (read) (write) Combined format - A master addresses a slave with a 10-bit address, then transmits data to this slave and reads data from this slave. From master to slave From slave to master 1998 Microchip Technology Inc. A = acknowledge (SDA low) A = not acknowledge (SDA high) S = Start Condition P = Stop Condition DS30289A-page 287 PIC17C7XX E.4 Multi-Master E.5 I2C The protocol allows a system to have more than one master. This is called multi-master. When two or more masters try to transfer data at the same time, arbitration and synchronization occur. E.4.1 ARBITRATION Arbitration takes place on the SDA line, while the SCL line is high. The master which transmits a high when the other master transmits a low loses arbitration (Figure E-9), and turns off its data output stage. A master which lost arbitration can generate clock pulses until the end of the data byte where it lost arbitration. When the master devices are addressing the same device, arbitration continues into the data. FIGURE E-9: MULTI-MASTER ARBITRATION (TWO MASTERS) Clock Synchronization Clock synchronization occurs after the devices have started arbitration. This is performed using a wired-AND connection to the SCL line. A high to low transition on the SCL line causes the concerned devices to start counting off their low period. Once a device clock has gone low, it will hold the SCL line low until its SCL high state is reached. The low to high transition of this clock may not change the state of the SCL line, if another device clock is still within its low period. The SCL line is held low by the device with the longest low period. Devices with shorter low periods enter a high wait-state, until the SCL line comes high. When the SCL line comes high, all devices start counting off their high periods. The first device to complete its high period will pull the SCL line low. The SCL line high time is determined by the device with the shortest high period, Figure E-10. FIGURE E-10: CLOCK SYNCHRONIZATION transmitter 1 loses arbitration DATA 1 SDA wait state DATA 1 DATA 2 start counting HIGH period CLK 1 SDA CLK 2 SCL counter reset SCL Masters that also incorporate the slave function, and have lost arbitration must immediately switch over to slave-receiver mode. This is because the winning master-transmitter may be addressing it. Arbitration is not allowed between: • A repeated START condition • A STOP condition and a data bit • A repeated START condition and a STOP condition E.6 I2C Timing Specifications Table E-2 (Figure E-11) and Table E-3 (Figure E-12) show the timing specifications as required by the Philips specification for I2C. For additional information please refer to Section 15.2 and Section 20.5. Care needs to be taken to ensure that these conditions do not occur. DS30289A-page 288 1998 Microchip Technology Inc. PIC17C7XX FIGURE E-11: I2C BUS START/STOP BITS TIMING SPECIFICATION SCL 93 91 90 92 SDA STOP Condition START Condition TABLE E-2: I2C BUS START/STOP BITS TIMING SPECIFICATION Microchip Parameter No. Sym 90 TSU:STA START condition Setup time 100 kHz mode 400 kHz mode 4700 600 — — — — ns Only relevant for repeated START condition 91 THD:STA START condition Hold time 100 kHz mode 400 kHz mode 4000 600 — — — — ns After this period the first clock pulse is generated 92 TSU:STO 93 THD:STO STOP condition Setup time STOP condition Hold time 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode 4700 600 4000 ‡ 600 ‡ — — — — — — — — Characteristic 1998 Microchip Technology Inc. Min Typ Max Units Conditions ns ns DS30289A-page 289 PIC17C7XX FIGURE E-12: I2C BUS DATA TIMING SPECIFICATION 103 102 100 101 SCL 90 106 107 91 92 SDA In 110 109 109 SDA Out I2C BUS DATA TIMING SPECIFICATION TABLE E-3: Microchip Parameter No. Sym Characteristic Min Max Units 100 THIGH Clock high time 100 kHz mode 400 kHz mode 4.0 0.6 — — µs µs 101 TLOW Clock low time 100 kHz mode 400 kHz mode 4.7 1.3 — — µs µs 102 TR SDA and SCL rise time 100 kHz mode 400 kHz mode — 20 + 0.1Cb 1000 300 ns ns SDA and SCL fall time 100 kHz mode 400 kHz mode — 20 + 0.1Cb 300 300 ns ns 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode 4.7 0.6 4.0 0.6 — — — — µs µs µs µs 103 TF 90 TSU:STA START condition setup time 91 THD:STA START condition hold time 106 THD:DAT Data input hold time 100 kHz mode 400 kHz mode 0 0 — 0.9 ns µs 107 TSU:DAT Data input setup time 100 kHz mode 400 kHz mode 250 100 — — ns ns 92 TSU:STO STOP condition setup time 100 kHz mode 400 kHz mode 4.7 0.6 — — µs µs 109 TAA Output valid from clock 110 TBUF Bus free time 100 kHz mode 400 kHz mode 100 kHz mode 400 kHz mode — — 4.7 1.3 3500 1000 — — ns ns µs µs Conditions Cb is specified to be from 10 to 400 pF Cb is specified to be from 10 to 400 pF Only relevant for repeated START condition After this period the first clock pulse is generated Note 2 Note 1 Time the bus must be free before a new transmission can start D102 Cb Bus capacitive loading — 400 pF Note 1: As a transmitter, the device must provide this internal minimum delay time to bridge the undefined region (min. 300 ns) of the falling edge of SCL to avoid unintended generation of START or STOP conditions. 2: A fast-mode I2C-bus device can be used in a standard-mode I2C-bus system, but the requirement tsu;DAT ≥ 250 ns must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line TR max.+tsu;DAT = 1000 + 250 = 1250 ns (according to the standard-mode I2C bus specification) before the SCL line is released. DS30289A-page 290 1998 Microchip Technology Inc. PIC17C7XX APPENDIX F: STATUS AND CONTROL REGISTERS FIGURE F-1: PIC17C7XX REGISTER FILE MAP Addr Unbanked 00h 01h 02h 03h 04h 05h 06h 07h 08h 09h 0Ah 0Bh 0Ch 0Dh 0Eh 0Fh INDF0 FSR0 PCL PCLATH ALUSTA T0STA CPUSTA INTSTA INDF1 FSR1 WREG TMR0L TMR0H TBLPTRL TBLPTRH BSR Bank 0 10h 11h 12h 13h 14h 15h 16h 17h Bank 1 (1) Bank 2 (1) Bank 3 (1) Bank 4 (1) Bank 5 (1) Bank 6 (1) Bank 7 (1) Bank 8 (4) PORTA DDRC TMR1 PW1DCL PIR2 DDRF SSPADD PW3DCL DDRH DDRB PORTC TMR2 PW2DCL PIE2 PORTF SSPCON1 PW3DCH PORTH PORTB DDRD TMR3L PW1DCH — DDRG SSPCON2 CA3L DDRJ RCSTA1 PORTD TMR3H PW2DCH RCSTA2 PORTG SSPSTAT CA3H PORTJ RCREG1 DDRE PR1 CA2L RCREG2 ADCON0 SSPBUF CA4L — TXSTA1 PORTE PR2 CA2H TXSTA2 ADCON1 — CA4H — TXREG1 PIR1 PR3L/CA1L TCON1 TXREG2 ADRESL — TCON3 — SPBRG1 PIE1 PR3H/CA1H TCON2 SPBRG2 ADRESH — — — Unbanked 18h 19h 1Ah 1Fh PRODL PRODH General Purpose RAM Bank 0 (2) Bank 1 (2) Bank 2 (2, 3) Bank 3 (2, 3) 20h 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. 1998 Microchip Technology Inc. DS30289A-page 291 PIC17C7XX FIGURE F-2: ALUSTA REGISTER (ADDRESS: 04h, UNBANKED) R/W - 1 R/W - 1 R/W - 1 R/W - 1 FS3 FS2 FS1 FS0 bit7 R/W - x OV R/W - x Z R/W - x DC R/W - x C bit0 R = Readable bit W = Writable bit -n = Value at POR reset (x = unknown) 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 bit 5-4: FS1:FS0: FSR0 Mode Select bits 00 = Post auto-decrement FSR0 value 01 = Post auto-increment FSR0 value 1x = FSR0 value does not change bit 3: 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 bit 2: Z: Zero bit 1 = The result of an arithmetic or logic operation is zero 0 = The results of an arithmetic or logic operation is not zero bit 1: 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: For borrow the polarity is reversed. bit 0: 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: For borrow the polarity is reversed. DS30289A-page 292 1998 Microchip Technology Inc. PIC17C7XX FIGURE F-3: R/W - 0 INTEDG bit7 T0STA REGISTER (ADDRESS: 05h, UNBANKED) 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 — bit0 R = Readable bit W = Writable bit U = Unimplemented, reads as ‘0’ -n = Value at POR reset 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 bit 6: 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 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 Timer0. 1 = Internal instruction clock cycle (TCY) 0 = External clock input on the T0CKI pin bit 4-1: 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 Unimplemented: Read as '0' 1998 Microchip Technology Inc. DS30289A-page 293 PIC17C7XX FIGURE F-4: U-0 — bit7 CPUSTA REGISTER (ADDRESS: 06h, UNBANKED) U-0 — R-1 R/W - 1 STKAV GLINTD R-1 TO R-1 PD R/W - 0 POR R/W - 1 BOR bit0 R = Readable bit W = Writable bit U = Unimplemented bit, Read as ‘0’ - n = Value at POR reset bit 7-6: Unimplemented: Read as '0' bit 5: 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) bit 4: 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 un-masked interrupts bit 3: TO: WDT Time-out Status bit 1 = After power-up or by a CLRWDT instruction 0 = A Watchdog Timer time-out occurred bit 2: PD: Power-down Status bit 1 = After power-up or by the CLRWDT instruction 0 = By execution of the SLEEP instruction bit 1: POR: Power-on Reset Status bit 1 = No Power-on Reset occurred 0 = A Power-on Reset occurred (must be set by software after a Power-on Reset occurs) bit 0: 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 DS30289A-page 294 1998 Microchip Technology Inc. PIC17C7XX FIGURE F-5: R-0 PEIF bit7 INTSTA REGISTER (ADDRESS: 07h, UNBANKED) R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 T0CKIF T0IF INTF PEIE T0CKIE T0IE INTE bit0 R = Readable bit W = Writable bit - n = Value at POR reset bit 7: 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 bit 6: 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 bit 5: 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 bit 4: 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 bit 3: 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 bit 2: 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 bit 1: T0IE: TMR0 Overflow Interrupt Enable bit 1 = Enable TMR0 overflow interrupt 0 = Disable TMR0 overflow interrupt bit 0: 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 1998 Microchip Technology Inc. DS30289A-page 295 PIC17C7XX FIGURE F-6: PIE1 REGISTER (ADDRESS: 17h, BANK 1) R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 RBIE TMR3IE TMR2IE TMR1IE CA2IE CA1IE TX1IE RC1IE bit7 bit0 bit 7: RBIE: PORTB Interrupt on Change Enable bit 1 = Enable PORTB interrupt on change 0 = Disable PORTB interrupt on change bit 6: TMR3IE: TMR3 Interrupt Enable bit 1 = Enable TMR3 interrupt 0 = Disable TMR3 interrupt bit 5: TMR2IE: TMR2 Interrupt Enable bit 1 = Enable TMR2 interrupt 0 = Disable TMR2 interrupt bit 4: TMR1IE: TMR1 Interrupt Enable bit 1 = Enable TMR1 interrupt 0 = Disable TMR1 interrupt bit 3: CA2IE: Capture2 Interrupt Enable bit 1 = Enable Capture2 interrupt 0 = Disable Capture2 interrupt bit 2: CA1IE: Capture1 Interrupt Enable bit 1 = Enable Capture1 interrupt 0 = Disable Capture1 interrupt bit 1: TX1IE: USART1 Transmit Interrupt Enable bit 1 = Enable USART1 Transmit buffer empty interrupt 0 = Disable USART1 Transmit buffer empty interrupt bit 0: RC1IE: USART1 Receive Interrupt Enable bit 1 = Enable USART1 Receive buffer full interrupt 0 = Disable USART1 Receive buffer full interrupt DS30289A-page 296 R = Readable bit W = Writable bit -n = Value at POR reset 1998 Microchip Technology Inc. PIC17C7XX FIGURE F-7: PIE2 REGISTER (ADDRESS: 11h, BANK 4) R/W - 0 R/W - 0 SSPIE BCLIE bit7 R/W - 0 ADIE U-0 — R/W - 0 CA4IE R/W - 0 CA3IE bit 7: SSPIE: Synchronous Serial Port Interrupt Enable bit 1 = Enable SSP Interrupt 0 = Disable SSP Interrupt bit 6: BCLIE: Bus Collision Interrupt Enable bit 1 = Enable Bus Collision Interrupt 0 = Disable Bus Collision Interrupt bit 5: ADIE: A/D Module Interrupt Enable bit 1 = Enable A/D Module Interrupt 0 = Disable A/D Module Interrupt bit 4: Unimplemented: Read as ‘0’ bit 3: CA4IE: Capture4 Interrupt Enable bit 1 = Enable Capture4 Interrupt 0 = Disable Capture4 Interrupt bit 2: CA3IE: Capture3 Interrupt Enable bit 1 = Enable Capture3 Interrupt 0 = Disable Capture3 Interrupt bit 1: TX2IE: USART2 Transmit Interrupt Enable bit 1 = Enable USART2 Transmit Buffer Empty Interrupt 0 = Disable USART2 Transmit Buffer Empty Interrupt bit 0: RC2IE: USART2 Receive Interrupt Enable bit 1 = Enable USART2 Receive Buffer Full Interrupt 0 = Disable USART2 Receive Buffer Full Interrupt 1998 Microchip Technology Inc. R/W - 0 TX2IE R/W - 0 RC2IE bit0 R = Readable bit W = Writable bit -n = Value at POR reset DS30289A-page 297 PIC17C7XX FIGURE F-8: PIR1 REGISTER (ADDRESS: 16h, BANK 1) R/W - x R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R - 1 R - 0 RBIF TMR3IF TMR2IF TMR1IF CA2IF CA1IF TX1IF RC1IF bit7 bit0 R = Readable bit W = Writable bit -n = Value at POR reset 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 bit 6: 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 bit 4: 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 bit 2: CA1IF: Capture1 Interrupt Flag bit 1 = Capture event occurred on RB0/CAP1 pin 0 = Capture event did not occur on RB0/CAP1 pin bit 1: TX1IF: USART1 Transmit Interrupt Flag bit (State controlled by hardware) 1 = USART1 Transmit buffer is empty 0 = USART1 Transmit buffer is full bit 0: RC1IF: USART1 Receive Interrupt Flag bit (State controlled by hardware) 1 = USART1 Receive buffer is full 0 = USART1 Receive buffer is empty DS30289A-page 298 1998 Microchip Technology Inc. PIC17C7XX FIGURE F-9: PIR2 REGISTER (ADDRESS: 10h, BANK 4) R/W - 0 R/W - 0 SSPIF BCLIF bit7 R/W - 0 ADIF U-0 — R/W - 0 CA4IF R/W - 0 CA3IF R-1 TX2IF R-0 RC2IF bit0 R = Readable bit W = Writable bit -n = Value at POR reset bit 7: 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. I2C Slave / Master A transmission/reception has taken place. I2C 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 (Multimaster system). A stop condition occurred while the SSP module was idle (Multimaster 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 bit 5: ADIF: A/D Module Interrupt Flag bit 1 = An A/D conversion is complete 0 = An A/D conversion is not complete bit 4: Unimplemented: Read as '0' bit 3: CA4IF: Capture4 Interrupt Flag bit 1 = Capture event occurred on RE3/CAP4 pin 0 = Capture event did not occur on RE3/CAP4 pin bit 2: CA3IF: Capture3 Interrupt Flag bit 1 = Capture event occurred on RG4/CAP3 pin 0 = Capture event did not occur on RG4/CAP3 pin bit 1: TX2IF:USART2 Transmit Interrupt Flag bit (State controlled by hardware) 1 = USART2 Transmit buffer is empty 0 = USART2 Transmit buffer is full bit 0: RC2IF: USART2 Receive Interrupt Flag bit (State controlled by hardware) 1 = USART2 Receive buffer is full 0 = USART2 Receive buffer is empty 1998 Microchip Technology Inc. DS30289A-page 299 PIC17C7XX FIGURE F-10: TXSTA1 REGISTER (ADDRESS: 15h, BANK 0) TXSTA2 REGISTER (ADDRESS: 15h, BANK 4) R/W - 0 R/W - 0 R/W - 0 R/W - 0 CSRC TX9 TXEN SYNC bit7 U-0 — U-0 — R-1 TRMT 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 bit 5: TXEN: Transmit Enable bit 1 = Transmit enabled 0 = Transmit disabled SREN/CREN overrides TXEN in SYNC mode bit 4: SYNC: USART Mode Select bit (Synchronous/Asynchronous) 1 = Synchronous mode 0 = Asynchronous mode R/W - x TX9D bit0 R = Readable bit W = Writable bit -n = Value at POR reset (x = unknown) bit 3-2: Unimplemented: Read as '0' bit 1: TRMT: Transmit Shift Register (TSR) Empty bit 1 = TSR empty 0 = TSR full bit 0: TX9D: 9th bit of transmit data (can be used to calculated the parity in software) DS30289A-page 300 1998 Microchip Technology Inc. PIC17C7XX FIGURE F-11: RCSTA1 REGISTER (ADDRESS: 13h, BANK 0) RCSTA2 REGISTER (ADDRESS: 13h, BANK 4) R/W - 0 R/W - 0 R/W - 0 R/W - 0 SPEN RX9 SREN CREN bit7 U-0 — R- 0 FERR R-0 OERR R-x RX9D bit 0 R = Readable bit W = Writable bit -n = Value at POR reset (x = unknown) bit 7: SPEN: Serial Port Enable bit 1 = Configures TX/CK and RX/DT pins as serial port pins 0 = Serial port disabled bit 6: RX9: 9-bit Receive Select bit 1 = Selects 9-bit reception 0 = Selects 8-bit reception bit 5: 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: Unimplemented: Read as '0' bit 2: FERR: Framing Error bit 1 = Framing error (Updated by reading RCREG) 0 = No framing error bit 1: OERR: Overrun Error bit 1 = Overrun (Cleared by clearing CREN) 0 = No overrun error bit 0: RX9D: 9th bit of receive data (can be the software calculated parity bit) 1998 Microchip Technology Inc. DS30289A-page 301 PIC17C7XX FIGURE F-12: TCON1 REGISTER (ADDRESS: 16h, BANK 3) R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 CA2ED1 CA2ED0 CA1ED1 CA1ED0 T16 TMR3CS TMR2CS TMR1CS bit7 bit0 R = Readable bit W = Writable bit -n = Value at POR reset 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 bit 5-4: 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 bit 3: T16: Timer2:Timer1 Mode Select bit 1 = Timer2 and Timer1 form a 16-bit timer 0 = Timer2 and Timer1 are two 8-bit timers bit 2: 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 bit 1: 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 bit 0: 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 DS30289A-page 302 1998 Microchip Technology Inc. PIC17C7XX FIGURE F-13: TCON2 REGISTER (ADDRESS: 17h, BANK 3) R-0 R-0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 CA2OVF CA1OVF PWM2ON PWM1ON CA1/PR3 TMR3ON TMR2ON TMR1ON bit7 bit0 R = Readable bit W = Writable bit -n = Value at POR reset bit 7: 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 bit 6: 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 bit 5: 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) bit 4: 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) bit 3: 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) bit 2: TMR3ON: Timer3 On bit 1 = Starts Timer3 0 = Stops Timer3 bit 1: 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 bit 0: 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 1998 Microchip Technology Inc. DS30289A-page 303 PIC17C7XX FIGURE F-14: TCON3 REGISTER (ADDRESS: 16h, BANK 7) U-0 bit7 R-0 R-0 CA4OVF CA3OVF R/W - 0 R/W - 0 R/W - 0 R/W - 0 R/W - 0 CA4ED1 CA4ED0 CA3ED1 CA3ED0 PWM3ON bit0 bit 7: Unimplemented: Read as ‘0’ bit 6: 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 bit 5: 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 R = Readable bit W = Writable bit U = Unimplemented bit, Reads as ‘0’ -n = Value at POR reset bit 4-3: 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 bit 2-1: 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 bit 0: 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) DS30289A-page 304 1998 Microchip Technology Inc. PIC17C7XX FIGURE F-15: ADCON0 REGISTER (ADDRESS: 14h, BANK 5) R/W-0 CHS3 bit7 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 bit0 R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR reset 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 bit 3: Unimplemented: Read as '0' bit 2: 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: Unimplemented: Read as '0' bit 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 1998 Microchip Technology Inc. DS30289A-page 305 PIC17C7XX FIGURE F-16: ADCON1 REGISTER (ADDRESS 15h, BANK 5) R/W-0 R/W-0 ADCS1 ADCS0 bit7 R/W-0 ADFM U-0 — R/W-0 PCFG3 R/W-0 PCFG2 R/W-0 PCFG1 R/W-0 PCFG0 bit0 R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR reset 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 oscillation) bit 5: 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’. bit 4: Unimplemented: Read as '0' bit 3-0: PCFG3:PCFG1: A/D Port Configuration Control bits PCFG3:PCFG1 AN15 AN14 AN13 AN12 AN11 AN10 AN9 AN8 AN7 AN6 AN5 AN4 AN3 AN2 AN1 AN0 000 001 A D A A A A A A A A A A A A A A A D A A A A A A A A A A A A A A 010 011 100 D D D D D D A D D A A D A A A A A A A A A A A A D D D D D D A D D A A D A A A A A A A A A A A A 101 110 D D D D D D D D D D A D A A A A D D D D D D D D D D A D A A A A 111 D D D D D D D D D D D D D D D D A = Analog input bit 0: D = Digital I/O 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. DS30289A-page 306 1998 Microchip Technology Inc. PIC17C7XX FIGURE F-17: SSPSTAT: SYNC SERIAL PORT STATUS REGISTER (ADDRESS: 13h, BANK 6) R/W-0 SMP bit7 bit 7: R/W-0 R-0 CKE D/A R-0 P R-0 S R-0 R/W R-0 UA R-0 BF bit0 R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR reset SMP: SPI Data Input Sample Phase 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 I2C 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 15-9, Figure 15-11, and Figure 15-12) 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 slave mode only) 1 = Indicates that the last byte received or transmitted was data 0 = Indicates that the last byte received or transmitted was address bit 4: P: Stop bit (I2C mode only) This bit is cleared when the SSP 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 bit 3: S: Start bit (I2C mode only) This bit is cleared when the SSP 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 bit 2: 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 I2C slave mode: 1 = Read 0 = Write In I2C 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 SSP is in IDLE mode. bit 1: UA: Update Address (10-bit I2C slave mode only) 1 = Indicates that the user needs to update the address in the SSPADD register 0 = Address does not need to be updated bit 0: 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 1998 Microchip Technology Inc. DS30289A-page 307 PIC17C7XX FIGURE F-18: SSPCON1: SYNC SERIAL PORT CONTROL REGISTER (ADDRESS 11h, BANK 6) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 WCOL SSPOV SSPEN CKP SSPM3 SSPM2 SSPM1 SSPM0 bit7 bit0 R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR reset bit 7: 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 bit 6: 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 by software). 0 = No overflow In I2C 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. SSPOV must be cleared in software in either mode. 0 = No overflow bit 5: 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 I2C 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, pins must be properly configured as input or output. bit 4: CKP: Clock Polarity Select bit In SPI mode 1 = Idle state for clock is a high level 0 = Idle state for clock is a low level In I2C slave mode SCK release control 1 = Enable clock 0 = Holds clock low (clock stretch) (Used to ensure data setup time) In I2C master mode Unused in this mode bit 3-0: 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 DS30289A-page 308 1998 Microchip Technology Inc. PIC17C7XX FIGURE F-19: SSPCON2: SYNC SERIAL PORT CONTROL REGISTER2 (ADDRESS 12h, BANK 6) R/W-0 GCEN bit7 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 ACKSTAT ACKDT ACKEN RCEN PEN R/W-0 RSEN R/W-0 SEN bit0 R = Readable bit W = Writable bit U = Unimplemented bit, Read as ‘0’ - n = Value at POR reset 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. bit 6: 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: RCEN: Receive Enable bit (In I2C master mode only). 1 = Enables Receive mode for I2C 0 = Receive idle Note: bit 2: 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). 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: bit 0: 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). 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: bit 1: 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). 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) 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). 1998 Microchip Technology Inc. DS30289A-page 309 PIC17C7XX NOTES: DS30289A-page 310 1998 Microchip Technology Inc. PIC17C7XX INDEX A A/D Accuracy/Error .......................................................... 187 ADCON0 Register..................................................... 177 ADCON1 Register..................................................... 178 ADIF bit ..................................................................... 179 Analog Input Model Block Diagram........................... 182 Analog-to-Digital Converter....................................... 177 Block Diagram........................................................... 179 Configuring Analog Port Pins.................................... 184 Configuring the Interrupt ........................................... 179 Configuring the Module............................................. 179 Connection Considerations....................................... 187 Conversion Clock...................................................... 183 Conversions .............................................................. 184 Converter Characteristics ......................................... 260 Delays ....................................................................... 181 Effects of a Reset...................................................... 186 Equations .................................................................. 181 Flowchart of A/D Operation....................................... 185 GO/DONE bit ............................................................ 179 Internal Sampling Switch (Rss) Impedence .............. 181 Operation During Sleep ............................................ 186 Sampling Requirements............................................ 181 Sampling Time .......................................................... 181 Source Impedence.................................................... 181 Time Delays .............................................................. 181 Transfer Function...................................................... 187 A/D Interrupt................................................................ 36, 299 A/D Interrupt Flag bit, ADIF......................................... 36, 299 A/D Module Interrupt Enable, ADIE ............................ 34, 297 ACK........................................................................... 142, 286 Acknowledge Data bit, AKD.............................................. 134 Acknowledge Data bitr, AKD............................................. 309 Acknowledge Pulse........................................................... 142 Acknowledge Sequence Enable bit, AKE ................. 134, 309 Acknowledge Status bit, AKS ................................... 134, 309 ADCON0 ............................................................................. 47 ADCON1 ............................................................................. 47 ADDLW ............................................................................. 200 ADDWF ............................................................................. 200 ADDWFC .......................................................................... 201 ADIE............................................................................ 34, 297 ADIF ............................................................................ 36, 299 ADRES Register ............................................................... 177 ADRESH ............................................................................. 47 ADRESL.............................................................................. 47 AKD........................................................................... 134, 309 AKE........................................................................... 134, 309 AKS................................................................... 134, 157, 309 ALU ....................................................................................... 9 ALUSTA ...................................................................... 46, 196 ALUSTA Register................................................................ 49 ANDLW ............................................................................. 201 ANDWF ............................................................................. 202 Application Note AN552,'Implementing Wake-up on Keystroke.' ..................................................................... 72 Application Note AN578, "Use of the SSP Module in the I2C Multi-Master Environment." .............................. 141 Assembler MPASM Assembler................................................... 232 Asynchronous Master Transmission................................. 122 Asynchronous Transmitter ................................................ 121 B Bank Select Register (BSR)................................................ 56 Banking ......................................................................... 44, 56 1998 Microchip Technology Inc. Baud Rate Formula .......................................................... 118 Baud Rate Generator ....................................................... 151 Baud Rate Generator (BRG) ............................................ 118 Baud Rates Asynchronous Mode................................................. 120 Synchronous Mode................................................... 119 BCF .................................................................................. 202 BCLIE ......................................................................... 34, 297 BCLIF ......................................................................... 36, 299 BF ..................................................... 132, 142, 157, 160, 307 Bit Manipulation ................................................................ 196 Block Diagrams A/D............................................................................ 179 Analog Input Model................................................... 182 Baud Rate Generator ............................................... 151 BSR Operation ........................................................... 56 External Brown-out Protection Circuit (Case1)........... 29 External Power-on Reset Circuit ................................ 22 External Program Memory Connection ...................... 43 I2C Master Mode ...................................................... 149 I2C Module................................................................ 141 Indirect Addressing..................................................... 53 On-chip Reset Circuit ................................................. 21 PORTD ....................................................................... 78 PORTE ........................................................... 80, 88, 89 Program Counter Operation ....................................... 55 PWM......................................................................... 105 RA0 and RA1.............................................................. 70 RA2............................................................................. 70 RA3............................................................................. 71 RA4 and RA5.............................................................. 71 RB3:RB2 Port Pins ..................................................... 73 RB7:RB4 and RB1:RB0 Port Pins .............................. 72 RC7:RC0 Port Pins..................................................... 76 SSP (I2C Mode)........................................................ 141 SSP (SPI Mode) ....................................................... 135 SSP Module (I2C Master Mode) ............................... 131 SSP Module (I2C Slave Mode) ................................. 131 SSP Module (SPI Mode) .......................................... 131 Timer3 with One Capture and One Period Register .................................................................... 108 TMR1 and TMR2 in 16-bit Timer/Counter Mode ...... 103 TMR1 and TMR2 in Two 8-bit Timer/Counter Mode......................................................................... 102 TMR3 with Two Capture Registers........................... 110 Using CALL, GOTO.................................................... 55 WDT ......................................................................... 191 BODEN ............................................................................... 29 Borrow ...................................................................................9 BRG .......................................................................... 118, 151 Brown-out Protection .......................................................... 29 Brown-out Reset (BOR)...................................................... 29 BSF................................................................................... 203 BSR .............................................................................. 46, 56 BSR Operation ................................................................... 56 BTFSC .............................................................................. 203 BTFSS .............................................................................. 204 BTG .................................................................................. 204 Buffer Full bit, BF .............................................................. 142 Buffer Full Status bit, BF........................................... 132, 307 Bus Arbitration .................................................................. 168 Bus Collision Section...................................................................... 168 Bus Collision During a RESTART Condition .................... 171 Bus Collision During a Start Condition ............................. 169 Bus Collision During a Stop Condition.............................. 172 Bus Collision Interrupt Enable, BCLIE ........................ 34, 297 Bus Collision Interrupt Flag bit, BCLIF ....................... 36, 299 DS30289A-page 311 PIC17C7XX C C.............................................................................. 9, 49, 292 C Compiler ........................................................................ 233 CA1/PR3 ........................................................................... 100 CA1ED0 .............................................................................. 99 CA1ED1 .............................................................................. 99 CA1IE.................................................................................. 33 CA1IF .......................................................................... 35, 298 CA1OVF............................................................................ 100 CA2ED0 .............................................................................. 99 CA2ED1 .............................................................................. 99 CA2H............................................................................. 26, 47 CA2IE.......................................................................... 33, 109 CA2IF .................................................................. 35, 109, 298 CA2L ............................................................................. 26, 47 CA2OVF............................................................................ 100 CA3H................................................................................... 48 CA3IE.......................................................................... 34, 297 CA3IF .......................................................................... 36, 299 CA3L ................................................................................... 48 CA4H................................................................................... 48 CA4IE.......................................................................... 34, 297 CA4IF .......................................................................... 36, 299 Calculating Baud Rate Error ............................................. 118 CALL ........................................................................... 52, 205 Capacitor Selection Ceramic Resonators ................................................... 16 Crystal Oscillator ......................................................... 16 Capture ....................................................................... 99, 108 Capture Sequence to Read Example................................ 111 Capture1 Mode ........................................................................... 99 Overflow............................................ 100, 101, 303, 304 Capture1 Interrupt ....................................................... 35, 298 Capture2 Mode ........................................................................... 99 Overflow............................................ 100, 101, 303, 304 Capture2 Interrupt ....................................................... 35, 298 Capture3 Interrupt Enable, CA3IE .............................. 34, 297 Capture3 Interrupt Flag bit, CA3IF .............................. 36, 299 Capture4 Interrupt Enable, CA4IE .............................. 34, 297 Capture4 Interrupt Flag bit, CA4IF .............................. 36, 299 Carry (C) ............................................................................... 9 Ceramic Resonators ........................................................... 15 Circular Buffer ..................................................................... 52 CKE........................................................................... 132, 307 CKP........................................................................... 133, 308 Clearing the Prescaler....................................................... 191 Clock Polarity Select bit, CKP ................................... 133, 308 Clock/Instruction Cycle (Figure) .......................................... 19 Clocking Scheme/Instruction Cycle..................................... 19 CLRF................................................................................. 205 CLRWDT........................................................................... 206 Code Examples Indirect Addressing ..................................................... 53 Loading the SSPBUF register................................... 136 Saving Status and WREG in RAM.............................. 40 Table Read ................................................................. 62 Table Write.................................................................. 60 Code Protection ................................................................ 193 COMF................................................................................ 206 Configuration Bits ............................................................................ 190 Locations................................................................... 190 Oscillator ............................................................. 15, 190 Word ......................................................................... 189 DS30289A-page 312 CPFSEQ ........................................................................... 207 CPFSGT ........................................................................... 207 CPFSLT ............................................................................ 208 CPUSTA ............................................................... 46, 50, 192 Crystal Operation, Overtone Crystals ................................. 16 Crystal or Ceramic Resonator Operation............................ 16 Crystal Oscillator................................................................. 15 D D/A............................................................................ 132, 307 Data Memory GPR ...................................................................... 41, 44 Indirect Addressing ..................................................... 53 Organization ............................................................... 44 SFR ............................................................................ 41 Data Memory Banking ........................................................ 44 Data/Address bit, D/A ............................................... 132, 307 DAW ................................................................................. 208 DC........................................................................... 9, 49, 292 DDRB...................................................................... 25, 46, 72 DDRC ..................................................................... 26, 46, 76 DDRD ..................................................................... 26, 46, 78 DDRE...................................................................... 26, 46, 80 DDRF.................................................................................. 47 DDRG ................................................................................. 47 DECF ................................................................................ 209 DECFSNZ......................................................................... 210 DECFSZ ........................................................................... 209 Delay From External Clock Edge........................................ 96 Development Support ....................................................... 231 Development Tools........................................................... 231 Digit Borrow .......................................................................... 9 Digit Carry (DC) .................................................................... 9 Duty Cycle ........................................................................ 105 E Electrical Characteristics PIC17C752/756 Absolute Maximum Ratings.............................. 235 Capture Timing ................................................. 251 CLKOUT and I/O Timing .................................. 248 DC Characteristics............................................ 237 External Clock Timing....................................... 247 Memory Interface Read Timing ........................ 263 Memory Interface Write Timing ........................ 262 Parameter Measurement Information............... 246 Reset, Watchdog Timer, Oscillator Start-up Timer and Power-up Timer Timing ................... 249 Timer0 Clock Timing......................................... 250 Timer1, Timer2 and Timer3 Clock Timing ........ 250 Timing Parameter Symbology .......................... 245 USART Module Synchronous Receive Timing............................................................... 258 USART Module Synchronous Transmission Timing............................................................... 258 EPROM Memory Access Time Order Suffix....................... 43 Extended Microcontroller .................................................... 41 Extended Microcontroller Mode .......................................... 43 External Memory Interface.................................................. 43 External Program Memory Waveforms............................... 43 F Family of Devices PIC17C75X................................................................... 6 FERR ................................................................................ 123 Flowcharts Acknowledge ............................................................ 164 Master Receiver ....................................................... 161 Master Transmit........................................................ 158 1998 Microchip Technology Inc. PIC17C7XX Restart Condition ...................................................... 155 Start Condition .......................................................... 153 Stop Condition .......................................................... 166 FOSC0 .............................................................................. 189 FOSC1 .............................................................................. 189 FS0 ............................................................................. 49, 292 FS1 ............................................................................. 49, 292 FS2 ............................................................................. 49, 292 FS3 ............................................................................. 49, 292 FSR0............................................................................. 46, 53 FSR1............................................................................. 46, 53 Fuzzy Logic Dev. System (fuzzyTECH-MP) .................. 233 G GCE .......................................................................... 134, 309 General Call Address Sequence....................................... 147 General Call Address Support .......................................... 147 General Call Enable bit, GCE ................................... 134, 309 General Format for Instructions ........................................ 196 General Purpose RAM........................................................ 41 General Purpose RAM Bank............................................... 56 General Purpose Register (GPR) ....................................... 44 GLINTD ......................................................... 37, 50, 109, 192 Global Interrupt Disable bit, GLINTD .................................. 37 GOTO ............................................................................... 210 GPR (General Purpose Register) ....................................... 44 GPR Banks ......................................................................... 56 Graphs IOH vs. VOH, VDD = 3V .............................................. 272 IOH vs. VOH, VDD = 5V .............................................. 273 IOL vs. VOL, VDD = 3V ............................................... 273 IOL vs. VOL, VDD = 5V ............................................... 274 Maximum IDD vs. Frequency (External Clock 125°C to -40°C) ........................................................ 269 Maximum IPD vs. VDD Watchdog Disabled ............... 270 Maximum IPD vs. VDD Watchdog Enabled................ 271 RC Oscillator Frequency vs. VDD (Cext = 100 pF) ... 266 RC Oscillator Frequency vs. VDD (Cext = 22 pF) ..... 266 RC Oscillator Frequency vs. VDD (Cext = 300 pF) ... 267 Transconductance of LF Oscillator vs.VDD ............... 268 Transconductance of XT Oscillator vs. VDD.............. 268 Typical IDD vs. Frequency (External Clock 25°C) ..... 269 Typical IPD vs. VDD Watchdog Disabled 25°C .......... 270 Typical IPD vs. VDD Watchdog Enabled 25°C ........... 271 Typical RC Oscillator vs. Temperature ..................... 265 VIH, VIL of MCLR, T0CKI and OSC1 (In RC Mode) vs. VDD ...................................................................... 275 VTH (Input Threshold Voltage) of I/O Pins vs. VDD ...................................................................... 274 VTH (Input Threshold Voltage) of OSC1 Input (In XT, HS, and LP Modes) vs. VDD......................... 275 WDT Timer Time-Out Period vs. VDD ....................... 272 H Hardware Multiplier ............................................................. 65 I I/O Ports Bi-directional ............................................................... 91 I/O Ports...................................................................... 69 Programming Considerations ..................................... 91 Read-Modify-Write Instructions................................... 91 Successive Operations ............................................... 92 I2C..................................................................................... 141 Addressing I2C Devices ............................................ 286 Arbitration.................................................................. 288 Combined Format ..................................................... 287 I2C Overview............................................................. 285 Initiating and Terminating Data Transfer................... 285 Master-Receiver Sequence ...................................... 287 1998 Microchip Technology Inc. Master-Transmitter Sequence .................................. 287 Multi-master.............................................................. 288 START...................................................................... 285 STOP................................................................ 285, 286 Transfer Acknowledge.............................................. 286 I2C Master Mode Receiver Flowchart............................... 161 I2C Master Mode Reception ............................................. 160 I2C Master Mode Restart Condition.................................. 154 I2C Mode Selection........................................................... 141 I2C Module Acknowledge Flowchart............................................ 164 Acknowledge Sequence timing ................................ 163 Addressing................................................................ 143 Baud Rate Generator ............................................... 151 Block Diagram .......................................................... 149 BRG Block Diagram ................................................. 151 BRG Reset due to SDA Collision ............................. 170 BRG Timing .............................................................. 151 Bus Arbitration .......................................................... 168 Bus Collision............................................................. 168 Acknowledge .................................................... 168 Restart Condition.............................................. 171 Restart Condition Timing (Case1) .................... 171 Restart Condition Timing (Case2) .................... 171 Start Condition.................................................. 169 Start Condition Timing .............................. 169, 170 Stop Condition .................................................. 172 Stop Condition Timing (Case1) ........................ 172 Stop Condition Timing (Case2) ........................ 172 Transmit Timing................................................ 168 Bus Collision timing .................................................. 168 Clock Arbitration ....................................................... 167 Clock Arbitration Timing (Master Transmit) .............. 167 Conditions to not give ACK Pulse............................. 142 General Call Address Support.................................. 147 Master Mode............................................................. 149 Master Mode 7-bit Reception timing......................... 162 Master Mode Operation............................................ 150 Master Mode Start Condition.................................... 152 Master Mode Transmission ...................................... 157 Master Mode Transmit Sequence ............................ 150 Master Transmit Flowchart ....................................... 158 Multi-Master Communication.................................... 168 Multi-master Mode.................................................... 150 Operation.................................................................. 141 Repeat Start Condition timing................................... 154 Restart Condition Flowchart ..................................... 155 Slave Mode............................................................... 142 Slave Reception ....................................................... 143 Slave Transmission .................................................. 144 SSPBUF ................................................................... 142 Start Condition Flowchart ......................................... 153 Stop Condition Flowchart ......................................... 166 Stop Condition Receive or Transmit timing .............. 165 Stop Condition timing ............................................... 165 Waveforms for 7-bit Reception ................................. 144 Waveforms for 7-bit Transmission............................ 144 2 I C Module Address Register, SSPADD .......................... 142 2C Slave Mode ................................................................ 142 I INCF ................................................................................. 211 INCFSNZ .......................................................................... 212 INCFSZ............................................................................. 211 In-Circuit Serial Programming .......................................... 194 INDF0 ........................................................................... 46, 53 INDF1 ........................................................................... 46, 53 Indirect Addressing Indirect Addressing..................................................... 53 Operation.................................................................... 53 DS30289A-page 313 PIC17C7XX Registers..................................................................... 53 Initialization Conditions for Special Function Registers ...... 25 Initializing PORTB ............................................................... 73 Initializing PORTC............................................................... 76 Initializing PORTD............................................................... 78 Initializing PORTE ................................................... 80, 82, 84 INSTA.................................................................................. 46 Instruction Flow/Pipelining .................................................. 19 Instruction Set ................................................................... 198 ADDLW ..................................................................... 200 ADDWF ..................................................................... 200 ADDWFC .................................................................. 201 ANDLW ..................................................................... 201 ANDWF ..................................................................... 202 BCF ........................................................................... 202 BSF ........................................................................... 203 BTFSC ...................................................................... 203 BTFSS ...................................................................... 204 BTG........................................................................... 204 CALL ......................................................................... 205 CLRF......................................................................... 205 CLRWDT................................................................... 206 COMF ....................................................................... 206 CPFSEQ ................................................................... 207 CPFSGT ................................................................... 207 CPFSLT .................................................................... 208 DAW.......................................................................... 208 DECF ........................................................................ 209 DECFSNZ ................................................................. 210 DECFSZ.................................................................... 209 GOTO ....................................................................... 210 INCF.......................................................................... 211 INCFSNZ .................................................................. 212 INCFSZ ..................................................................... 211 IORLW ...................................................................... 212 IORWF ...................................................................... 213 LCALL ....................................................................... 213 MOVFP ..................................................................... 214 MOVLB ..................................................................... 214 MOVLR ..................................................................... 215 MOVLW .................................................................... 215 MOVPF ..................................................................... 216 MOVWF .................................................................... 216 MULLW ..................................................................... 217 MULWF ..................................................................... 217 NEGW ....................................................................... 218 NOP .......................................................................... 218 RETFIE ..................................................................... 219 RETLW ..................................................................... 219 RETURN ................................................................... 220 RLCF......................................................................... 220 RLNCF ...................................................................... 221 RRCF ........................................................................ 221 RRNCF ..................................................................... 222 SETF ......................................................................... 222 SLEEP ...................................................................... 223 SUBLW ..................................................................... 223 SUBWF ..................................................................... 224 SUBWFB................................................................... 224 SWAPF ..................................................................... 225 TABLRD............................................................ 225, 226 TABLWT ........................................................... 226, 227 TLRD......................................................................... 227 TLWT ........................................................................ 228 TSTFSZ .................................................................... 228 XORLW ..................................................................... 229 XORWF..................................................................... 229 DS30289A-page 314 Instruction Set Summary .................................................. 195 Instructions TABLRD ..................................................................... 62 TLRD .......................................................................... 62 INT Pin................................................................................ 38 INTE.................................................................................... 32 INTEDG ........................................................................ 51, 95 Inter-Integrated Circuit (I2C) ............................................. 131 Internal Sampling Switch (Rss) Impedence...................... 181 Interrupt on Change Feature .............................................. 72 Interrupt Status Register (INTSTA)..................................... 32 Interrupts A/D Interrupt ....................................................... 36, 299 Bus Collision Interrupt ........................................ 36, 299 Capture1 Interrupt .............................................. 35, 298 Capture2 Interrupt .............................................. 35, 298 Capture3 Interrupt .............................................. 36, 299 Capture4 Interrupt .............................................. 36, 299 Context Saving ........................................................... 37 Flag bits TMR1IE .............................................................. 31 TMR1IF............................................................... 31 TMR2IE .............................................................. 31 TMR2IF............................................................... 31 TMR3IE .............................................................. 31 TMR3IF............................................................... 31 Global Interrupt Disable .............................................. 37 Interrupts .................................................................... 31 Logic ........................................................................... 31 Operation .................................................................... 37 Peripheral Interrupt Enable......................................... 33 Peripheral Interrupt Request ...................................... 35 PIE2 Register ............................................................. 34 PIR1 Register ............................................................. 35 PIR2 Register ............................................................. 36 PORTB Interrupt on Change .............................. 35, 298 PWM ......................................................................... 106 RA0/INT ...................................................................... 37 Status Register ........................................................... 32 Synchronous Serial Port Interrupt ...................... 36, 299 T0CKI Interrupt ........................................................... 37 Timing ......................................................................... 38 TMR1 Overflow Interrupt .................................... 35, 298 TMR2 Overflow Interrupt .................................... 35, 298 TMR3 Overflow Interrupt .................................... 35, 298 USART1 Receive Interrupt ................................. 35, 298 USART1 Transmit Interrupt ................................ 35, 298 USART2 Receive Interrupt ................................. 36, 299 Vectors Peripheral Interrupt............................................. 37 Program Memory Locations ............................... 41 RA0/INT Interrupt ............................................... 37 T0CKI Interrupt ................................................... 37 Vectors/Priorities ........................................................ 37 Wake-up from SLEEP .............................................. 192 INTF.................................................................................... 32 INTSTA ............................................................................... 46 INTSTA Register................................................................. 32 IORLW .............................................................................. 212 IORWF.............................................................................. 213 L LCALL......................................................................... 52, 213 M Maps Register File Map ............................................... 45, 291 Memory External Interface ....................................................... 43 1998 Microchip Technology Inc. PIC17C7XX External Memory Waveforms...................................... 43 Memory Map (Different Modes) .................................. 42 Mode Memory Access ................................................ 42 Organization................................................................ 41 Program Memory ........................................................ 41 Program Memory Map ................................................ 41 Microcontroller .................................................................... 41 Microprocessor ................................................................... 41 Minimizing Current Consumption...................................... 193 MOVFP ....................................................................... 44, 214 Moving Data Between Data and Program Memories.......... 44 MOVLB ....................................................................... 44, 214 MOVLR ............................................................................. 215 MOVLW ............................................................................ 215 MOVPF ....................................................................... 44, 216 MOVWF ............................................................................ 216 MPLAB-C .......................................................................... 233 MPSIM Software Simulator............................................... 233 MULLW ............................................................................. 217 Multi-Master Communication ............................................ 168 Multi-Master Mode ............................................................ 150 Multiply Examples 16 x 16 Routine........................................................... 66 16 x 16 Signed Routine............................................... 67 8 x 8 Routine............................................................... 65 8 x 8 Signed Routine................................................... 65 MULWF ............................................................................. 217 N NEGW ............................................................................... 218 NOP .................................................................................. 218 O Opcode Field Descriptions................................................ 195 Opcodes.............................................................................. 55 Oscillator Configuration....................................................... 15, 190 Crystal......................................................................... 15 External Clock............................................................. 17 External Crystal Circuit ............................................... 17 External Parallel Resonant Crystal Circuit .................. 17 External Series Resonant Crystal Circuit.................... 17 RC............................................................................... 18 RC Frequencies ........................................................ 267 Oscillator Start-up Time (Figure)......................................... 22 Oscillator Start-up Timer (OST) .......................................... 22 OST..................................................................................... 22 OV........................................................................... 9, 49, 292 Overflow (OV) ....................................................................... 9 P P................................................................................ 132, 307 Packaging Information ...................................................... 277 PC (Program Counter) ........................................................ 55 PCFG0 bit ................................................................. 178, 306 PCFG1 bit ................................................................. 178, 306 PCFG2 bit ................................................................. 178, 306 PCH .................................................................................... 55 PCL ....................................................................... 46, 55, 196 PCLATH........................................................................ 46, 55 PD ............................................................................... 50, 192 PEIE............................................................................ 32, 109 PEIF .................................................................................... 32 Peripheral Bank .................................................................. 56 Peripheral Banks................................................................. 56 Peripheral Interrupt Enable ................................................. 33 Peripheral Interrupt Request (PIR1) ................................... 35 Peripheral Register Banks .................................................. 44 PICDEM-1 Low-Cost PIC16/17 Demo Board ................... 232 1998 Microchip Technology Inc. PICDEM-2 Low-Cost PIC16CXX Demo Board................. 232 PICDEM-3 Low-Cost PIC16C9XXX Demo Board ............ 232 PICMASTER In-Circuit Emulator ...................................... 231 PICSTART Low-Cost Development System .................... 231 PIE .................................................................... 124, 128, 130 PIE1 .............................................................................. 26, 46 PIE2 ........................................................................ 26, 34, 47 PIR.................................................................... 124, 128, 130 PIR1.............................................................................. 26, 46 PIR2.............................................................................. 26, 47 PM0 .......................................................................... 189, 193 PM1 .......................................................................... 189, 193 POP .............................................................................. 37, 52 POR .................................................................................... 22 PORTA ................................................................... 25, 46, 70 PORTB ................................................................... 25, 46, 72 PORTB Interrupt on Change ...................................... 35, 298 PORTC ................................................................... 26, 46, 76 PORTD ................................................................... 26, 46, 78 PORTE ................................................................... 26, 46, 80 PORTF ............................................................................... 47 PORTG ............................................................................... 47 Power-down Mode............................................................ 192 Power-on Reset (POR)....................................................... 22 Power-up Timer (PWRT) .................................................... 22 PR1............................................................................... 26, 47 PR2............................................................................... 26, 47 PR3/CA1H .......................................................................... 26 PR3/CA1L........................................................................... 26 PR3H/CA1H ....................................................................... 47 PR3L/CA1L......................................................................... 47 Prescaler Assignments ....................................................... 97 PRO MATE Universal Programmer .................................. 231 PRODH......................................................................... 28, 48 PRODL ......................................................................... 28, 48 Program Counter (PC)........................................................ 55 Program Memory External Access Waveforms....................................... 43 External Connection Diagram..................................... 43 Map............................................................................. 41 Modes Extended Microcontroller.................................... 41 Microcontroller .................................................... 41 Microprocessor ................................................... 41 Protected Microcontroller ................................... 41 Operation.................................................................... 41 Organization ............................................................... 41 Protected Microcontroller.................................................... 41 PS0 ............................................................................... 51, 95 PS1 ............................................................................... 51, 95 PS2 ............................................................................... 51, 95 PS3 ............................................................................... 51, 95 PUSH............................................................................ 37, 52 PW1DCH ...................................................................... 26, 47 PW1DCL....................................................................... 26, 47 PW2DCH ...................................................................... 26, 47 PW2DCL....................................................................... 26, 47 PW3DCH ...................................................................... 28, 48 PW3DCL....................................................................... 28, 48 PWM ........................................................................... 99, 105 Duty Cycle ................................................................ 106 External Clock Source .............................................. 107 Frequency vs. Resolution ......................................... 106 Interrupts .................................................................. 106 Max Resolution/Frequency for External Clock Input.......................................................................... 107 Output....................................................................... 105 DS30289A-page 315 PIC17C7XX Periods...................................................................... 106 PWM1 ....................................................... 100, 101, 303, 304 PWM1ON .................................................................. 100, 105 PWM2 ....................................................... 100, 101, 303, 304 PWM2ON .................................................................. 100, 105 PWM3ON .................................................................. 101, 304 PWRT.................................................................................. 22 R R/W ........................................................................... 132, 307 R/W bit ...................................................................... 143, 286 R/W bit .............................................................................. 143 RA1/T0CKI pin .................................................................... 95 RBIE.................................................................................... 33 RBIF .................................................................................... 35 RBPU .................................................................................. 72 RC Oscillator ....................................................................... 18 RC Oscillator Frequencies ................................................ 267 RC1IE.................................................................................. 33 RC1IF.......................................................................... 35, 298 RC2IE.......................................................................... 34, 297 RC2IF.......................................................................... 36, 299 RCE,Receive Enable bit, RCE .................................. 134, 309 RCREG ..................................................... 123, 124, 128, 129 RCREG1 ....................................................................... 25, 46 RCREG2 ....................................................................... 25, 47 RCSTA .............................................................. 124, 128, 130 RCSTA1 ........................................................................ 25, 46 RCSTA2 ........................................................................ 25, 47 Read/Write bit, R/W .................................................. 132, 307 Reading 16-bit Value........................................................... 97 Receive Overflow Indicator bit, SSPOV .................... 133, 308 Receive Status and Control Register ................................ 115 Register File Map ........................................................ 45, 291 Registers ADCON0 ..................................................................... 47 ADCON1 ..................................................................... 47 ADRESH ..................................................................... 47 ADRESL...................................................................... 47 ALUSTA .......................................................... 37, 46, 49 BRG .......................................................................... 118 BSR....................................................................... 37, 46 CA2H .......................................................................... 47 CA2L ........................................................................... 47 CA3H .......................................................................... 48 CA3L ........................................................................... 48 CA4H .......................................................................... 48 CA4L ........................................................................... 48 CPUSTA ............................................................... 46, 50 DDRB .......................................................................... 46 DDRC.......................................................................... 46 DDRD.......................................................................... 46 DDRE .......................................................................... 46 DDRF .......................................................................... 47 DDRG ......................................................................... 47 FSR0..................................................................... 46, 53 FSR1..................................................................... 46, 53 INDF0.................................................................... 46, 53 INDF1.................................................................... 46, 53 INSTA ......................................................................... 46 INTSTA ....................................................................... 32 PCL ............................................................................. 46 PCLATH...................................................................... 46 PIE1 ...................................................................... 33, 46 PIE2 ...................................................................... 34, 47 PIR1 ...................................................................... 35, 46 PIR2 ...................................................................... 36, 47 PORTA........................................................................ 46 DS30289A-page 316 PORTB ....................................................................... 46 PORTC ....................................................................... 46 PORTD ....................................................................... 46 PORTE ....................................................................... 46 PORTF ....................................................................... 47 PORTG ....................................................................... 47 PR1............................................................................. 47 PR2............................................................................. 47 PR3H/CA1H ............................................................... 47 PR3L/CA1L................................................................. 47 PRODH....................................................................... 48 PRODL ....................................................................... 48 PW1DCH .................................................................... 47 PW1DCL..................................................................... 47 PW2/DCL.................................................................... 47 PW2DCH .................................................................... 47 PW3DCH .................................................................... 48 PW3DCL..................................................................... 48 RCREG1..................................................................... 46 RCREG2..................................................................... 47 RCSTA1 ..................................................................... 46 RCSTA2 ..................................................................... 47 SPBRG1 ..................................................................... 46 SPBRG2 ..................................................................... 47 Special Function Table ............................................... 46 SSPADD ..................................................................... 48 SSPBUF ..................................................................... 48 SSPCON1 .................................................................. 48 SSPCON2 .................................................................. 48 SSPSTAT ........................................................... 48, 132 T0STA ............................................................ 46, 51, 95 TBLPTRH ................................................................... 46 TBLPTRL .................................................................... 46 TCON1 ................................................................. 47, 99 TCON2 ............................................................... 47, 100 TCON3 ............................................................... 48, 101 TMR0H ....................................................................... 46 TMR1 .......................................................................... 47 TMR2 .......................................................................... 47 TMR3H ....................................................................... 47 TMR3L ........................................................................ 47 TXREG1 ..................................................................... 46 TXREG2 ..................................................................... 47 TXSTA1 ...................................................................... 46 TXSTA2 ...................................................................... 47 WREG .................................................................. 37, 46 Regsters TMR0L ........................................................................ 46 Reset Section........................................................................ 21 Status Bits and Their Significance .............................. 23 Time-Out in Various Situations ................................... 23 Time-Out Sequence ................................................... 23 Restart Condition Enabled bit, RSE.......................... 134, 309 RETFIE ............................................................................. 219 RETLW ............................................................................. 219 RETURN........................................................................... 220 RLCF ................................................................................ 220 RLNCF.............................................................................. 221 RRCF................................................................................ 221 RRNCF ............................................................................. 222 RSE .......................................................................... 134, 309 RX Pin Sampling Scheme ................................................ 123 S S ............................................................................... 132, 307 SAE........................................................................... 134, 309 Sampling........................................................................... 123 1998 Microchip Technology Inc. PIC17C7XX Saving STATUS and WREG in RAM.................................. 40 SCK................................................................................... 135 SCL ................................................................................... 142 SDA................................................................................... 142 SDI .................................................................................... 135 SDO .................................................................................. 135 Serial Clock, SCK ............................................................. 135 Serial Clock, SCL.............................................................. 142 Serial Data Address, SDA................................................. 142 Serial Data In, SDI ............................................................ 135 Serial Data Out, SDO........................................................ 135 SETF ................................................................................. 222 SFR ................................................................................... 196 SFR (Special Function Registers)....................................... 41 SFR As Source/Destination .............................................. 196 Signed Math.......................................................................... 9 Slave Select Synchronization ........................................... 138 Slave Select, SS ............................................................... 135 SLEEP ...................................................................... 192, 223 SMP .......................................................................... 132, 307 Software Simulator (MPSIM) ............................................ 233 SPBRG ............................................................. 124, 128, 130 SPBRG1 ....................................................................... 25, 46 SPBRG2 ....................................................................... 25, 47 SPE........................................................................... 134, 309 Special Features of the CPU ............................................ 189 Special Function Registers ................................... 41, 46, 196 Summary..................................................................... 46 Special Function Registers, File Map ......................... 45, 291 SPI Master Mode ............................................................. 137 Serial Clock............................................................... 135 Serial Data In ............................................................ 135 Serial Data Out ......................................................... 135 Serial Peripheral Interface (SPI) ............................... 131 Slave Select .............................................................. 135 SPI clock ................................................................... 137 SPI Mode .................................................................. 135 SPI Clock Edge Select, CKE .................................... 132, 307 SPI Data Input Sample Phase Select, SMP ............. 132, 307 SPI Master/Slave Connection ........................................... 136 SPI Module Master/Slave Connection.......................................... 136 Slave Mode ............................................................... 138 Slave Select Synchronization ................................... 138 Slave Synch Timnig .................................................. 138 SS ..................................................................................... 135 SSP................................................................................... 131 Block Diagram (SPI Mode) ....................................... 135 SPI Mode .................................................................. 135 SSPADD ........................................................... 142, 143 SSPBUF............................................................ 137, 142 SSPCON1................................................................. 133 SSPCON2................................................................. 134 SSPSR.............................................................. 137, 142 SSPSTAT.......................................................... 132, 142 SSP I2C SSP I2C Operation.................................................... 141 SSP Module SPI Master Mode ...................................................... 137 SPI Master./Slave Connection .................................. 136 SPI Slave Mode ........................................................ 138 SSPCON1 Register .................................................. 141 SSP Overflow Detect bit, SSPOV ..................................... 142 SSPADD ............................................................................. 48 SSPBUF...................................................................... 48, 142 SSPCON1........................................................... 48, 133, 141 1998 Microchip Technology Inc. SSPCON2 .................................................................. 48, 134 SSPEN ..................................................................... 133, 308 SSPIE ......................................................................... 34, 297 SSPIF ................................................................. 36, 143, 299 SSPM3:SSPM0 ........................................................ 133, 308 SSPOV ..................................................... 133, 142, 160, 308 SSPSTAT ........................................................... 48, 132, 142 Stack Operation.................................................................... 52 Pointer ........................................................................ 52 Stack........................................................................... 41 Start bit (S) ............................................................... 132, 307 Start Condition Enabled bit, SAE.............................. 134, 309 STKAV .......................................................................... 50, 52 Stop bit (P)................................................................ 132, 307 Stop Condition Enable bit ......................................... 134, 309 SUBLW ............................................................................. 223 SUBWF............................................................................. 224 SUBWFB .......................................................................... 224 SWAPF ............................................................................. 225 Synchronous Master Mode............................................... 125 Synchronous Master Reception ....................................... 127 Synchronous Master Transmission .................................. 125 Synchronous Serial Port ................................................... 131 Synchronous Serial Port Enable bit, SSPEN............ 133, 308 Synchronous Serial Port Interrupt .............................. 36, 299 Synchronous Serial Port Interrupt Enable, SSPIE...... 34, 297 Synchronous Serial Port Mode Select bits, SSPM3:SSPM0 ........................................................ 133, 308 Synchronous Slave Mode................................................. 129 T T0CKI ................................................................................. 37 T0CKI Pin ........................................................................... 38 T0CKIE ............................................................................... 32 T0CKIF ............................................................................... 32 T0CS ............................................................................ 51, 95 T0IE .................................................................................... 32 T0IF .................................................................................... 32 T0SE............................................................................. 51, 95 T0STA .......................................................................... 46, 51 T16 ..................................................................................... 99 Table Latch ......................................................................... 54 Table Pointer ...................................................................... 54 Table Read Example...................................................................... 62 Table Reads Section .................................................. 62 TLRD .......................................................................... 62 Table Write Code ........................................................................... 60 Timing......................................................................... 60 To External Memory ................................................... 60 TABLRD ................................................................... 225, 226 TABLWT ................................................................... 226, 227 TAD ................................................................................... 183 TBLATH .............................................................................. 54 TBLATL .............................................................................. 54 TBLPTRH ..................................................................... 46, 54 TBLPTRL ...................................................................... 46, 54 TCLK12 ...................................................................... 99, 302 TCLK3 ........................................................................ 99, 302 TCON1 ......................................................................... 26, 47 TCON2 ............................................................................... 47 TCON2,TCON3 .................................................................. 26 TCON3 ....................................................................... 48, 101 Time-Out Sequence ........................................................... 23 Timer Resources ................................................................ 93 DS30289A-page 317 PIC17C7XX Timer0 ................................................................................. 95 Timer1 16-bit Mode ............................................................... 103 Clock Source Select.................................................... 99 On bit ................................................ 100, 101, 303, 304 Section ................................................................ 99, 102 Timer2 16-bit Mode ............................................................... 103 Clock Source Select.................................................... 99 On bit ................................................ 100, 101, 303, 304 Section ................................................................ 99, 102 Timer3 Clock Source Select.................................................... 99 On bit ................................................ 100, 101, 303, 304 Section ................................................................ 99, 108 Timers TCON3 ...................................................................... 101 Timing Diagrams A/D Conversion......................................................... 261 Acknowledge Sequence Timing................................ 163 Asynchronous Master Transmission......................... 122 Asynchronous Reception .......................................... 124 Back to Back Asynchronous Master Transmission... 122 Baud Rate Generator with Clock Arbitration ............. 151 BRG Reset Due to SDA Collision ............................. 170 Bus Collision Start Condition Timing ...................................... 169 Bus Collision During a Restart Condition (Case 1) .................................................................... 171 Bus Collision During a Restart Condition (Case2) ..................................................................... 171 Bus Collision During a Start Condition (SCL = 0)................................................................... 170 Bus Collision During a Stop Condition ...................... 172 Bus Collision for Transmit and Acknowledge............ 168 External Parallel Resonant Crystal Oscillator Circuit .......................................................................... 17 External Program Memory Access ............................. 43 I2C Bus Data ............................................................. 257 I2C Bus Start/Stop bits .............................................. 256 I2C Master Mode First Start bit timing....................... 152 I2C Master Mode Reception timing ........................... 162 I2C Master Mode Transmission timing...................... 159 Interrupt (INT, TMR0 Pins).......................................... 38 Master Mode Transmit Clock Arbitration................... 167 Oscillator Start-up Time .............................................. 22 PIC17C752/756 Capture Timing............................... 251 PIC17C752/756 CLKOUT and I/O ............................ 248 PIC17C752/756 External Clock ................................ 247 PIC17C752/756 Memory Interface Read.................. 263 PIC17C752/756 Memory Interface Write .................. 262 PIC17C752/756 PWM Timing................................... 251 PIC17C752/756 Reset, Watchdog Timer, Oscillator Start-up Timer and Power-up Timer ......... 249 PIC17C752/756 Timer0 Clock .................................. 250 PIC17C752/756 Timer1, Timer2 and Timer3 Clock ......................................................................... 250 PIC17C752/756 USART Module Synchronous Receive ..................................................................... 258 PIC17C752/756 USART Module Synchronous Transmission............................................................. 258 Repeat Start Condition.............................................. 154 Slave Synchronization .............................................. 138 Stop Condition Receive or Transmit ......................... 165 Synchronous Reception............................................ 127 Synchronous Transmission....................................... 126 Table Write.................................................................. 60 DS30289A-page 318 TMR0 .................................................................... 96, 97 TMR0 Read/Write in Timer Mode ............................... 98 TMR1, TMR2, and TMR3 in Timer Mode ................. 113 Wake-Up from SLEEP .............................................. 192 TLRD ................................................................................ 227 TLWT ................................................................................ 228 TMR0 16-bit Read ................................................................. 97 16-bit Write ................................................................. 97 Module ........................................................................ 96 Operation .................................................................... 96 Overview..................................................................... 93 Prescaler Assignments ............................................... 97 Read/Write Considerations......................................... 97 Read/Write in Timer Mode.......................................... 98 Timing ................................................................... 96, 97 TMR0 Status/Control Register (T0STA) ............................. 51 TMR0H ............................................................................... 46 TMR0L ................................................................................ 46 TMR1 ............................................................................ 26, 47 8-bit Mode................................................................. 102 External Clock Input ................................................. 102 Overview..................................................................... 93 Timer Mode .............................................................. 113 Two 8-bit Timer/Counter Mode ................................. 102 Using with PWM ....................................................... 105 TMR1 Overflow Interrupt ............................................ 35, 298 TMR1CS ............................................................................. 99 TMR1IE............................................................................... 33 TMR1IF....................................................................... 35, 298 TMR1ON........................................................................... 100 TMR2 ............................................................................ 26, 47 8-bit Mode................................................................. 102 External Clock Input ................................................. 102 In Timer Mode .......................................................... 113 Two 8-bit Timer/Counter Mode ................................. 102 Using with PWM ....................................................... 105 TMR2 Overflow Interrupt ............................................ 35, 298 TMR2CS ............................................................................. 99 TMR2IE............................................................................... 33 TMR2IF....................................................................... 35, 298 TMR2ON........................................................................... 100 TMR3 Example, Reading From ........................................... 112 Example, Writing To ................................................. 112 External Clock Input ................................................. 112 In Timer Mode .......................................................... 113 One Capture and One Period Register Mode .......... 108 Overview..................................................................... 93 Reading/Writing ........................................................ 112 TMR3 Interrupt Flag bit, TMR3IF................................ 35, 298 TMR3CS ..................................................................... 99, 108 TMR3H ......................................................................... 26, 47 TMR3IE............................................................................... 33 TMR3IF....................................................................... 35, 108 TMR3L .......................................................................... 26, 47 TMR3ON................................................................... 100, 108 TO....................................................................... 50, 191, 192 Transmit Status and Control Register............................... 115 TSTFSZ ............................................................................ 228 Turning on 16-bit Timer .................................................... 103 TX1IE.................................................................................. 33 TX1IF .......................................................................... 35, 298 TX2IE.......................................................................... 34, 297 TX2IF .......................................................................... 36, 299 TXREG ..................................................... 121, 125, 129, 130 TXREG1 ....................................................................... 25, 46 1998 Microchip Technology Inc. PIC17C7XX TXREG2........................................................................ 25, 47 TXSTA .............................................................. 124, 128, 130 TXSTA1 ........................................................................ 25, 46 TXSTA2 ........................................................................ 25, 47 U UA ............................................................................. 132, 307 Update Address, UA ................................................. 132, 307 Upward Compatibility ............................................................ 5 USART Asynchronous Master Transmission......................... 122 Asynchronous Mode ................................................. 121 Asynchronous Receive ............................................. 123 Asynchronous Transmitter ........................................ 121 Baud Rate Generator................................................ 118 Synchronous Master Mode ....................................... 125 Synchronous Master Reception................................ 127 Synchronous Master Transmission........................... 125 Synchronous Slave Mode ......................................... 129 Synchronous Slave Transmit .................................... 129 USART1 Receive Interrupt ......................................... 35, 298 USART1 Transmit Interrupt ........................................ 35, 298 USART2 Receive Interrupt Enable, RC2IE................. 34, 297 USART2 Receive Interrupt Flag bit, RC2IF ................ 36, 299 USART2 Receive Interrupt Flag bit, TX2IF................. 36, 299 USART2 Transmit Interrupt Enable, TX2IE ................ 34, 297 V VDD ........................................................................... 237, 239 W Wake-up from SLEEP....................................................... 192 Wake-up from SLEEP Through Interrupt .......................... 192 Watchdog Timer................................................................ 191 Waveform for General Call Address Sequence ................ 147 Waveforms External Program Memory Access ............................. 43 WCOL ............................... 133, 152, 157, 160, 163, 165, 308 WCOL Status Flag ............................................................ 152 WDT .................................................................................. 191 Clearing the WDT ..................................................... 191 Normal Timer ............................................................ 191 Period........................................................................ 191 Programming Considerations ................................... 191 WDTPS0 ........................................................................... 189 WDTPS1 ........................................................................... 189 WREG ................................................................................. 46 Write Collision Detect bit, WCOL .............................. 133, 308 X XORLW ............................................................................. 229 XORWF............................................................................. 229 Z Z .............................................................................. 9, 49, 292 Zero (Z) ................................................................................. 9 1998 Microchip Technology Inc. DS30289A-page 319 PIC17C7XX NOTES: DS30289A-page 320 1998 Microchip Technology Inc. PIC17C7XX ON-LINE SUPPORT Microchip provides on-line support on the Microchip World Wide Web (WWW) site. The web site is used by Microchip as a means to make files and information easily available to customers. To view the site, the user must have access to the Internet and a web browser, such as Netscape or Microsoft Explorer. Files are also available for FTP download from our FTP site. Connecting to the Microchip Internet Web Site Systems Information and Upgrade Hot Line The Systems Information and Upgrade Line provides system users a listing of the latest versions of all of Microchip's development systems software products. Plus, this line provides information on how customers can receive any currently available upgrade kits.The Hot Line Numbers are: 1-800-755-2345 for U.S. and most of Canada, and 1-602-786-7302 for the rest of the world. 980106 The Microchip web site is available by using your favorite Internet browser to attach to: www.microchip.com The file transfer site is available by using an FTP service to connect to: ftp://ftp.futureone.com/pub/microchip The web site and file transfer site provide a variety of services. Users may download files for the latest Development Tools, Data Sheets, Application Notes, User's Guides, Articles and Sample Programs. A variety of Microchip specific business information is also available, including listings of Microchip sales offices, distributors and factory representatives. Other data available for consideration is: • Latest Microchip Press Releases • Technical Support Section with Frequently Asked Questions • Design Tips • Device Errata • Job Postings • Microchip Consultant Program Member Listing • Links to other useful web sites related to Microchip Products • Conferences for products, Development Systems, technical information and more • Listing of seminars and events 1998 Microchip Technology Inc. Trademarks: The Microchip name, logo, PIC, PICSTART, PICMASTER and PRO MATE are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. PICmicro, FlexROM, MPLAB and fuzzyLAB are trademarks and SQTP is a service mark of Microchip in the U.S.A. All other trademarks mentioned herein are the property of their respective companies. DS30289A-page 321 PIC17C7XX READER RESPONSE It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation can better serve you, please FAX your comments to the Technical Publications Manager at (602) 786-7578. Please list the following information, and use this outline to provide us with your comments about this Data Sheet. To: Technical Publications Manager RE: Reader Response Total Pages Sent From: Name Company Address City / State / ZIP / Country Telephone: (_______) _________ - _________ FAX: (______) _________ - _________ Application (optional): Would you like a reply? Device: PIC17C7XX Y N Literature Number: DS30289A Questions: 1. What are the best features of this document? 2. How does this document meet your hardware and software development needs? 3. Do you find the organization of this data sheet easy to follow? If not, why? 4. What additions to the data sheet do you think would enhance the structure and subject? 5. What deletions from the data sheet could be made without affecting the overall usefulness? 6. Is there any incorrect or misleading information (what and where)? 7. How would you improve this document? 8. How would you improve our software, systems, and silicon products? DS30289A-page 322 1998 Microchip Technology Inc. PIC17C7XX PIC17C7XX Product Identification System To order or to obtain information, e.g., on pricing or delivery, please use the listed part numbers, and refer to the factory or the listed sales offices. Examples PART NO. – XX X /XX XXX Pattern: Package: QTP, SQTP, ROM Code (factory specified) or Special Requirements. Blank for OTP and Windowed devices CL = Windowed LCC PT = TQFP L = PLCC Temperature Range: Frequency Range: – I 08 16 33 Device: PIC17C756 PIC17C756T PIC17LC756 = = = = = 0˚C to +70˚C –40˚C to +85˚C 8 MHz 16 MHz 33 MHz : Standard VDD range : (Tape and Reel) : Extended VDD range a) PIC17C756 – 16L Commercial Temp., PLCC package, 16 MHz, normal VDD limits b) PIC17LC756–08/PT Commercial Temp., TQFP package, 8MHz, extended VDD limits c) PIC17C756–33I/PT Industrial Temp., TQFP package, 33 MHz, normal VDD limits Sales and Support Products supported by a preliminary Data Sheet may possibly 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. The Microchip Website at www.microchip.com 2. Your local Microchip sales office (see following page) 3. The Microchip Corporate Literature Center U.S. FAX: (602) 786-7277 Please specify which device, revision of silicon and Data Sheet (include Literature #) you are using. For latest version information and upgrade kits for Microchip Development Tools, please call 1-800-755-2345 or 1-602-786-7302. 1998 Microchip Technology Inc. DS30289A-page 323 PIC17C7XX NOTES: DS30289A-page 324 1998 Microchip Technology Inc. PIC17C7XX NOTES: 1998 Microchip Technology Inc. DS30289A-page 325 PIC17C7XX NOTES: DS30289A-page 326 1998 Microchip Technology Inc. PIC17C7XX NOTES: 1998 Microchip Technology Inc. DS30289A-page 327 WORLDWIDE SALES AND SERVICE AMERICAS AMERICAS (continued) Corporate Office Toronto Singapore Microchip Technology Inc. 2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-786-7200 Fax: 480-786-7277 Technical Support: 480-786-7627 Web Address: http://www.microchip.com Microchip Technology Inc. 5925 Airport Road, Suite 200 Mississauga, Ontario L4V 1W1, Canada Tel: 905-405-6279 Fax: 905-405-6253 Microchip Technology Singapore Pte Ltd. 200 Middle Road #07-02 Prime Centre Singapore 188980 Tel: 65-334-8870 Fax: 65-334-8850 Atlanta Microchip Asia Pacific Unit 2101, Tower 2 Metroplaza 223 Hing Fong Road Kwai Fong, N.T., Hong Kong Tel: 852-2-401-1200 Fax: 852-2-401-3431 Microchip Technology Inc. 500 Sugar Mill Road, Suite 200B Atlanta, GA 30350 Tel: 770-640-0034 Fax: 770-640-0307 Boston Microchip Technology Inc. 5 Mount Royal Avenue Marlborough, MA 01752 Tel: 508-480-9990 Fax: 508-480-8575 Chicago Microchip Technology Inc. 333 Pierce Road, Suite 180 Itasca, IL 60143 Tel: 630-285-0071 Fax: 630-285-0075 Dallas Microchip Technology Inc. 4570 Westgrove Drive, Suite 160 Addison, TX 75248 Tel: 972-818-7423 Fax: 972-818-2924 Dayton Microchip Technology Inc. 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Tri-Atria Office Building 32255 Northwestern Highway, Suite 190 Farmington Hills, MI 48334 Tel: 248-538-2250 Fax: 248-538-2260 Los Angeles Microchip Technology Inc. 18201 Von Karman, Suite 1090 Irvine, CA 92612 Tel: 949-263-1888 Fax: 949-263-1338 New York Microchip Technology Inc. 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 ASIA/PACIFIC Hong Kong ASIA/PACIFIC (continued) Taiwan, R.O.C Microchip Technology Taiwan 10F-1C 207 Tung Hua North Road Taipei, Taiwan, ROC Tel: 886-2-2717-7175 Fax: 886-2-2545-0139 EUROPE Beijing United Kingdom Microchip Technology, Beijing Unit 915, 6 Chaoyangmen Bei Dajie Dong Erhuan Road, Dongcheng District New China Hong Kong Manhattan Building Beijing 100027 PRC Tel: 86-10-85282100 Fax: 86-10-85282104 Arizona Microchip Technology Ltd. 505 Eskdale Road Winnersh Triangle Wokingham Berkshire, England RG41 5TU Tel: 44 118 921 5858 Fax: 44-118 921-5835 India Denmark Microchip Technology Inc. India Liaison Office No. 6, Legacy, Convent Road Bangalore 560 025, India Tel: 91-80-229-0061 Fax: 91-80-229-0062 Microchip Technology Denmark ApS Regus Business Centre Lautrup hoj 1-3 Ballerup DK-2750 Denmark Tel: 45 4420 9895 Fax: 45 4420 9910 Japan France 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 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 Korea Germany 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 Arizona Microchip Technology GmbH Gustav-Heinemann-Ring 125 D-81739 München, Germany Tel: 49-89-627-144 0 Fax: 49-89-627-144-44 Shanghai 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 Microchip Technology RM 406 Shanghai Golden Bridge Bldg. 2077 Yan’an Road West, Hong Qiao District Shanghai, PRC 200335 Tel: 86-21-6275-5700 Fax: 86 21-6275-5060 Italy 11/15/99 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® 8-bit MCUs, KEELOQ® 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. © 1999 Microchip Technology Incorporated. Printed in the USA. 11/99 Printed on recycled paper. Information contained in this publication regarding device applications and the like is intended for suggestion only and may be superseded by updates. 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, 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. 1999 Microchip Technology Inc.