PIC12C67X 8-Pin, 8-Bit CMOS Microcontroller with A/D Converter and EEPROM Data Memory Devices Included in this Data Sheet: PDIP, SOIC, Windowed CERDIP PIC12C671 PIC12C672 PIC12CE673 PIC12CE674 Note: Throughout this data sheet PIC12C67X refers to the PIC12C671, PIC12C672, PIC12CE673 and PIC12CE674. PIC12CE67X refers to PIC12CE673 and PIC12CE674. Device * * * * * * Program Data RAM Data EEPROM PIC12C671 1024 x 14 128 x 8 -- PIC12C672 2048 x 14 128 x 8 -- PIC12CE673 1024 x 14 128 x 8 16 x 8 PIC12CE674 2048 x 14 128 x 8 16 x 8 14-bit wide instructions 8-bit wide data path Interrupt capability Special function hardware registers 8-level deep hardware stack Direct, indirect and relative addressing modes for data and instructions Peripheral Features: * Four-channel, 8-bit A/D converter * 8-bit real time clock/counter (TMR0) with 8-bit programmable prescaler * 1,000,000 erase/write cycle EEPROM data memory * EEPROM data retention > 40 years 1999 Microchip Technology Inc. 2 3 4 VDD 1 GP5/OSC1/CLKIN GP4/OSC2/AN3/ CLKOUT GP3/MCLR/VPP 2 3 4 PIC12CE673 PIC12CE674 Memory 1 8 7 6 VSS GP0/AN0 5 GP1/AN1/VREF GP2/T0CKI/AN2/ INT 8 VSS 7 GP0/AN0 6 GP1/AN1/VREF GP2/T0CKI/AN2/ INT PDIP, Windowed CERDIP High-Performance RISC CPU: * Only 35 single word instructions to learn * All instructions are single cycle (400 ns) except for program branches which are two-cycle * Operating speed: DC - 10 MHz clock input DC - 400 ns instruction cycle VDD GP5/OSC1/CLKIN GP4/OSC2/AN3/ CLKOUT GP3/MCLR/VPP PIC12C671 PIC12C672 * * * * Pin Diagrams: 5 Special Microcontroller Features: * * * * * * * * * * * * In-Circuit Serial Programming (ICSPTM) Internal 4 MHz oscillator with programmable calibration Selectable clockout 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 Programmable code protection Power saving SLEEP mode Interrupt-on-pin change (GP0, GP1, GP3) Internal pull-ups on I/O pins (GP0, GP1, GP3) Internal pull-up on MCLR pin Selectable oscillator options: - INTRC: Precision internal 4 MHz oscillator - EXTRC: External low-cost RC oscillator - XT: Standard crystal/resonator - HS: High speed crystal/resonator - LP: Power saving, low frequency crystal CMOS Technology: * Low-power, high-speed CMOS EPROM/EEPROM technology * Fully static design * Wide operating voltage range 2.5V to 5.5V * Commercial, Industrial and Extended temperature ranges * Low power consumption < 2 mA @ 5V, 4 MHz 15 A typical @ 3V, 32 kHz < 1 A typical standby current DS30561B-page 1 PIC12C67X Table of Contents 1.0 General Description ...................................................................................................................................................................... 3 2.0 PIC12C67X Device Varieties ........................................................................................................................................................ 5 3.0 Architectural Overview .................................................................................................................................................................. 7 4.0 Memory Organization.................................................................................................................................................................. 11 5.0 I/O Port........................................................................................................................................................................................ 25 6.0 EEPROM Peripheral Operation .................................................................................................................................................. 33 7.0 Timer0 Module ............................................................................................................................................................................ 39 8.0 Analog-to-Digital Converter (A/D) Module................................................................................................................................... 45 9.0 Special Features of the CPU....................................................................................................................................................... 53 10.0 Instruction Set Summary............................................................................................................................................................. 69 11.0 Development Support ................................................................................................................................................................. 83 12.0 Electrical Specifications .............................................................................................................................................................. 89 13.0 DC and AC Characteristics ....................................................................................................................................................... 109 14.0 Packaging Information .............................................................................................................................................................. 115 Appendix A:Compatibility ................................................................................................................................................................... 119 Appendix B:Code for Accessing EEPROM Data Memory ................................................................................................................. 119 Index .................................................................................................................................................................................................. 121 On-Line Support................................................................................................................................................................................. 125 Reader Response .............................................................................................................................................................................. 126 PIC12C67X Product Identification System ........................................................................................................................................ 127 To Our Valued Customers Most Current Data Sheet To automatically obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at: http://www.microchip.com You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page. The last character of the literature number is the version number. e.g., DS30000A is version A of document DS30000. New Customer Notification System Register on our web site (www.microchip.com/cn) to receive the most current information on our products. 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: (480) 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 webmaster@microchip.com. We appreciate your assistance in making this a better document. DS30561B-page 2 1999 Microchip Technology Inc. PIC12C67X 1.0 GENERAL DESCRIPTION The PIC12C67X devices are low-cost, high-performance, CMOS, fully-static, 8-bit microcontrollers with integrated analog-to-digital (A/D) converter and EEPROM data memory (EEPROM on PIC12CE67X versions only). All PICmicro(R) microcontrollers employ an advanced RISC architecture. The PIC12C67X microcontrollers have enhanced core features, eight-level deep stack, and multiple internal and external interrupt sources. The separate instruction and data buses of the Harvard architecture allow a 14-bit wide instruction word with the separate 8-bit wide data. 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 35 instructions (reduced instruction set) are available. Additionally, a large register set gives some of the architectural innovations used to achieve a very high performance. PIC12C67X microcontrollers typically achieve a 2:1 code compression and a 4:1 speed improvement over other 8-bit microcontrollers in their class. The PIC12C67X devices have 128 bytes of RAM, 16 bytes of EEPROM data memory (PIC12CE67X only), 5 I/O pins and 1 input pin. In addition a timer/counter is available. Also a 4-channel, high-speed, 8-bit A/D is provided. The 8-bit resolution is ideally suited for applications requiring low-cost analog interface, (i.e., thermostat control, pressure sensing, etc.) The PIC12C67X devices have special features to reduce external components, thus reducing cost, enhancing system reliability and reducing power consumption. The Power-On Reset (POR), Power-up Timer (PWRT), and Oscillator Start-up Timer (OST) eliminate the need for external reset circuitry. There are five oscillator configurations to choose from, including INTRC precision internal oscillator mode and the power-saving LP (Low Power) oscillator mode. Powersaving SLEEP mode, Watchdog Timer and code protection features improve system cost, power and reliability. The SLEEP (power-down) feature provides a power-saving mode. The user can wake-up the chip from SLEEP through several external and internal interrupts and resets. 1999 Microchip Technology Inc. A highly reliable Watchdog Timer with its own on-chip RC oscillator provides protection against software lock-up. A UV erasable windowed package version is ideal for code development, while the cost-effective One-TimeProgrammable (OTP) version is suitable for production in any volume. The customer can take full advantage of Microchip's price leadership in OTP microcontrollers, while benefiting from the OTP's flexibility. 1.1 Applications The PIC12C67X series fits perfectly in applications ranging from personal care appliances and security systems to low-power remote transmitters/receivers. The EPROM technology makes customizing application programs (transmitter codes, appliance settings, receiver frequencies, etc.) extremely fast and convenient, while the EEPROM data memory (PIC12CE67X only) technology allows for the changing of calibration factors and security codes. The small footprint packages, for through hole or surface mounting, make this microcontroller series perfect for applications with space limitations. Low-cost, low-power, high performance, ease of use and I/O flexibility make the PIC12C67X series very versatile even in areas where no microcontroller use has been considered before (i.e., timer functions, replacement of "glue" logic and PLD's in larger systems, coprocessor applications). 1.2 Family and Upward Compatibility The PIC12C67X products are compatible with other members of the 14-bit PIC16CXXX families. 1.3 Development Support The PIC12C67X devices are supported by a fullfeatured macro assembler, a software simulator, an incircuit emulator, a low-cost development programmer and a full-featured programmer. A "C" compiler and fuzzy logic support tools are also available. DS30561B-page 3 PIC12C67X TABLE 1-1: PIC12C67X & PIC12CE67X FAMILY OF DEVICES PIC12C671 Clock Memory Peripherals Features PIC12LC671 PIC12C672 PIC12LC672 PIC12CE673 PIC12LCE673 PIC12CE674 PIC12LCE674 Maximum Frequency of Operation (MHz) 10 10 10 10 10 10 10 10 EPROM Program Memory 1024 x 14 1024 x 14 2048 x 14 2048 x 14 1024 x 14 1024 x 14 2048 x 14 2048 x 14 RAM Data Memory (bytes) 128 128 128 128 128 128 128 128 EEPROM -- Data Memory (bytes) -- -- -- 16 16 16 16 Timer Module(s) TMR0 TMR0 TMR0 TMR0 TMR0 TMR0 TMR0 TMR0 A/D Converter (8-bit) Channels 4 4 4 4 4 4 4 4 Wake-up from SLEEP on pin change Yes Yes Yes Yes Yes Yes Yes Yes Interrupt Sources 4 4 4 4 4 4 4 4 I/O Pins 5 5 5 5 5 5 5 5 Input Pins 1 1 1 1 1 1 1 1 Internal Pull-ups Yes Yes Yes Yes Yes Yes Yes Yes In-Circuit Yes Serial Programming Yes Yes Yes Yes Yes Yes Yes Number of Instructions 35 35 35 35 35 35 35 Voltage 3.0V - 5.5V Range (Volts) 2.5V - 5.5V 3.0V - 5.5V 2.5V - 5.5V 3.0V - 5.5V 2.5V - 5.5V 3.0V - 5.5V 2.5V - 5.5V Packages 8-pin DIP, JW, SOIC 8-pin DIP, JW, SOIC 8-pin DIP, JW, SOIC 8-pin DIP, JW 8-pin DIP, JW 8-pin DIP, JW 8-pin DIP, JW 35 8-pin DIP, JW, SOIC All PIC12C67X devices have Power-on Reset, selectable Watchdog Timer, selectable code protect and high I/O current capability. All PIC12C67X devices use serial programming with data pin GP0 and clock pin GP1. DS30561B-page 4 1999 Microchip Technology Inc. PIC12C67X 2.0 PIC12C67X DEVICE VARIETIES A variety of frequency ranges and packaging options are available. Depending on application and production requirements, the proper device option can be selected using the information in the PIC12C67X Product Identification System section at the end of this data sheet. When placing orders, please use that page of the data sheet to specify the correct part number. For example, the PIC12C67X device "type" is indicated in the device number: 1. C, as in PIC12C671. These devices have EPROM type memory and operate over the standard voltage range. LC, as in PIC12LC671. These devices have EPROM type memory and operate over an extended voltage range. CE, as in PIC12CE674. These devices have EPROM type memory, EEPROM data memory and operate over the standard voltage range. LCE, as in PIC12LCE674. These devices have EPROM type memory, EEPROM data memory and operate over an extended voltage range. 2. 3. 4. 2.1 2.3 Quick-Turn-Programming (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-Turn Programming (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. UV Erasable Devices The UV erasable version, offered in windowed package, is optimal for prototype development and pilot programs. The UV erasable version can be erased and reprogrammed to any of the configuration modes. Microchip's PICSTART Plus and PRO MATE programmers both support the PIC12C67X. Third party programmers also are available; refer to the Microchip Third Party Guide for a list of sources. Note: 2.2 Please note that erasing the device will also erase the pre-programmed internal calibration value for the internal oscillator. The calibration value must be saved prior to erasing the part. One-Time-Programmable (OTP) Devices The availability of OTP devices is especially useful for customers who need the flexibility for frequent code updates and small volume applications. The OTP devices, packaged in plastic packages, permit the user to program them once. In addition to the program memory, the configuration bits must also be programmed. 1999 Microchip Technology Inc. DS30561B-page 5 PIC12C67X NOTES: DS30561B-page 6 1999 Microchip Technology Inc. PIC12C67X 3.0 ARCHITECTURAL OVERVIEW The high performance of the PIC12C67X family can be attributed to a number of architectural features commonly found in RISC microprocessors. To begin with, the PIC12C67X uses a Harvard architecture, in which program and data are accessed from separate memories using separate buses. This improves bandwidth over traditional von Neumann architecture in which program and data are fetched from the same memory using the same bus. Separating program and data buses also allow instructions to be sized differently than the 8-bit wide data word. Instruction opcodes are 14bits wide making it possible to have all single word instructions. A 14-bit wide program memory access bus fetches a 14-bit instruction in a single instruction cycle. A two-stage pipeline overlaps fetch and execution of instructions (Example 3-1). Consequently, all instructions (35) execute in a single cycle (400 ns @ 10 MHz) except for program branches. The table below lists program memory (EPROM), data memory (RAM), and non-volatile memory (EEPROM) for each PIC12C67X device. Device PIC12C671 PIC12C672 PIC12CE673 PIC12CE674 Program Memory RAM Data Memory EEPROM Data Memory 1K x 14 2K x 14 1K x 14 2K x 14 128 x 8 128 x 8 128 x 8 128 x 8 -- -- 16x8 16x8 1999 Microchip Technology Inc. The PIC12C67X can directly or indirectly address its register files or data memory. All special function registers, including the program counter, are mapped in the data memory. The PIC12C67X 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 PIC12C67X simple yet efficient. In addition, the learning curve is reduced significantly. PIC12C67X devices contain an 8-bit ALU and working register. The ALU is a general purpose arithmetic unit. It performs arithmetic and Boolean functions between the data in the working register and any register file. 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. In two-operand instructions, typically one operand is the working register (W register). The other operand is a file register or an immediate constant. In single operand instructions, the operand is either the W register or a file register. The W register is an 8-bit working register used for ALU operations. It is not an addressable register. Depending on the instruction executed, the ALU may affect the values of the Carry (C), Digit Carry (DC), and Zero (Z) bits in the STATUS register. The C and DC bits operate as a borrow bit and a digit borrow out bit, respectively, in subtraction. See the SUBLW and SUBWF instructions for examples. DS30561B-page 7 PIC12C67X PIC12C67X BLOCK DIAGRAM Device Program Memory Data Memory (RAM) Non-Volatile Memory (EEPROM) PIC12C671 1K x 14 128 x 8 -- PIC12C672 2K x 14 128 x 8 -- PIC12CE673 1K x 14 128 x 8 16 x 8 PIC12CE674 2K x 14 128 x 8 16 x 8 13 Program Bus GP0/AN0 GP1/AN1/VREF GP2/T0CKI/AN2/INT GP3/MCLR/VPP GP4/OSC2/AN3/CLKOUT GP5/OSC1/CLKIN RAM 128 bytes File Registers 8 Level Stack (13 bit) 14 RAM Addr (1) 9 Addr MUX Instruction reg Direct Addr 7 8 Indirect Addr FSR reg 3 Power-up Timer OSC1/CLKIN OSC2/CLKOUT Internal 4 MHz Clock Timing Generation 16x8 EEPROM Data Memory PIC12CE673 PIC12CE674 STATUS reg 8 Instruction Decode & Control GPIO SCL EPROM Program Memory 8 Data Bus Program Counter SDA FIGURE 3-1: Oscillator Start-up Timer Watchdog Timer Power-on Reset MUX ALU 8 W reg Timer0 MCLR VDD, VSS A/D Note 1: Higher order bits are from the STATUS Register. DS30561B-page 8 1999 Microchip Technology Inc. PIC12C67X TABLE 3-1: PIC12C67X PINOUT DESCRIPTION DIP Pin # I/O/P Type GP0/AN0 7 I/O TTL/ST Bi-directional I/O port/serial programming data/analog input 0. Can be software programmed for internal weak pull-up and interrupt-on-pin change. This buffer is a Schmitt Trigger input when used in serial programming mode. GP1/AN1/VREF 6 I/O TTL/ST Bi-directional I/O port/serial programming clock/analog input 1/ voltage reference. Can be software programmed for internal weak pull-up and interrupt-on-pin change. This buffer is a Schmitt Trigger input when used in serial programming mode. GP2/T0CKI/AN2/INT 5 I/O GP3/MCLR/VPP 4 I GP4/OSC2/AN3/CLKOUT 3 I/O GP5/OSC1/CLKIN 2 I/O VDD 1 P -- Positive supply for logic and I/O pins. VSS 8 P -- Ground reference for logic and I/O pins. Name Buffer Type ST Description Bi-directional I/O port/analog input 2. Can be configured as T0CKI or external interrupt. TTL/ST Input port/master clear (reset) input/programming voltage input. When configured as MCLR, this pin is an active low reset to the device. Voltage on MCLR/VPP must not exceed VDD during normal device operation. Can be software programmed for internal weak pull-up and interrupt-on-pin change. Weak pull-up always on if configured as MCLR . This buffer is Schmitt Trigger when in MCLR mode. TTL Bi-directional I/O port/oscillator crystal output/analog input 3. Connections to crystal or resonator in crystal oscillator mode (HS, XT and LP modes only, GPIO in other modes). In EXTRC and INTRC modes, the pin output can be configured to CLKOUT, which has 1/4 the frequency of OSC1 and denotes the instruction cycle rate. TTL/ST Bi-directional IO port/oscillator crystal input/external clock source input (GPIO in INTRC mode only, OSC1 in all other oscillator modes). Schmitt trigger input for EXTRC oscillator mode. Legend: I = input, O = output, I/O = input/output, P = power, -- = not used, TTL = TTL input, ST = Schmitt Trigger input. 1999 Microchip Technology Inc. DS30561B-page 9 PIC12C67X 3.1 Clocking Scheme/Instruction Cycle 3.2 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 is shown in Figure 3-2. 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 (i.e., GOTO), then two cycles are required to complete the instruction (Example 3-1). A fetch cycle begins with the program counter (PC) incrementing in Q1. In the execution cycle, the fetched instruction is latched into the "Instruction Register" (IR) in cycle Q1. This instruction is then decoded and executed during the Q2, Q3, and Q4 cycles. Data memory is read during Q2 (operand read) and written during Q4 (destination write). FIGURE 3-2: CLOCK/INSTRUCTION CYCLE Q1 Q2 Q3 Q4 Q2 Q1 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 Q1 Q2 Internal phase clock Q3 Q4 PC OSC2/CLKOUT (EXTRC and INTRC modes) EXAMPLE 3-1: 1. MOVLW 55h PC PC+1 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 TCY0 TCY1 Fetch 1 Execute 1 2. MOVWF GPIO 3. CALL SUB_1 4. BSF GPIO, 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. DS30561B-page 10 1999 Microchip Technology Inc. PIC12C67X 4.0 MEMORY ORGANIZATION 4.1 Program Memory Organization The PIC12C67X has a 13-bit program counter capable of addressing an 8K x 14 program memory space. For the PIC12C671 and the PIC12CE673, the first 1K x 14 (0000h-03FFh) is implemented. For the PIC12C672 and the PIC12CE674, the first 2K x 14 (0000h-07FFh) is implemented. Accessing a location above the physically implemented address will cause a wraparound. The reset vector is at 0000h and the interrupt vector is at 0004h. FIGURE 4-1: PIC12C67X PROGRAM MEMORY MAP AND STACK Data Memory Organization The data memory is partitioned into two banks, which contain the General Purpose Registers and the Special Function Registers. Bit RP0 is the bank select bit. RP0 (STATUS<5>) = 1 Bank 1 RP0 (STATUS<5>) = 0 Bank 0 Each Bank extends up to 7Fh (128 bytes). The lower locations of each Bank are reserved for the Special Function Registers. Above the Special Function Registers are General Purpose Registers implemented as static RAM. Both Bank 0 and Bank 1 contain Special Function Registers. Some "high use" Special Function Registers from Bank 0 are mirrored in Bank 1 for code reduction and quicker access. Also note that F0h through FFh on the PIC12C67X is mapped into Bank 0 registers 70h-7Fh as common RAM. PC<12:0> CALL, RETURN RETFIE, RETLW 4.2 13 4.2.1 GENERAL PURPOSE REGISTER FILE The register file can be accessed either directly or indirectly through the File Select Register FSR (Section 4.5). Stack Level 1 Stack Level 8 Reset Vector 0000h Peripheral Interrupt Vector 0004h 0005h On-Chip Program Memory (PIC12C672 and PIC12CE674 only) 03FFh 0400h 07FFh 0800h 1FFFh 1999 Microchip Technology Inc. DS30561B-page 11 PIC12C67X FIGURE 4-2: PIC12C67X REGISTER FILE MAP File Address 00h 01h 02h 03h 04h 05h 06h 07h 08h 09h 0Ah 0Bh 0Ch 0Dh 0Eh 0Fh 10h 11h 12h 13h 14h 15h 16h 17h 18h 19h 1Ah 1Bh 1Ch 1Dh 1Eh 1Fh 20h File Address INDF(1) TMR0 PCL STATUS FSR GPIO INDF(1) OPTION PCL STATUS FSR TRIS PCLATH INTCON PIR1 PCLATH INTCON PIE1 PCON OSCCAL ADRES ADCON0 ADCON1 General Purpose Register General Purpose Register 70h 7Fh Mapped in Bank 0 Bank 0 80h 81h 82h 83h 84h 85h 86h 87h 88h 89h 8Ah 8Bh 8Ch 8Dh 8Eh 8Fh 90h 91h 92h 93h 94h 95h 96h 97h 98h 99h 9Ah 9Bh 9Ch 9Dh 9Eh 9Fh 4.2.2 SPECIAL FUNCTION REGISTERS The Special Function Registers are registers used by the CPU and Peripheral Modules for controlling the desired operation of the device. These registers are implemented as static RAM. The Special Function Registers can be classified into two sets (core and peripheral). Those registers associated with the "core" functions are described in this section, and those related to the operation of the peripheral features are described in the section of that peripheral feature. A0h BFh C0h EFh F0h FFh Bank 1 Unimplemented data memory locations, read as '0'. Note 1: Not a physical register. DS30561B-page 12 1999 Microchip Technology Inc. PIC12C67X TABLE 4-1: Address PIC12C67X SPECIAL FUNCTION REGISTER SUMMARY Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on Power-on Reset Value on all other Resets(3) Bank 0 00h(1) INDF Addressing this location uses contents of FSR to address data memory (not a physical register) 0000 0000 0000 0000 01h TMR0 Timer0 module's register xxxx xxxx uuuu uuuu 02h(1) PCL Program Counter's (PC) Least Significant Byte 0000 0000 0000 0000 0001 1xxx 000q quuu xxxx xxxx uuuu uuuu (1) 03h STATUS 04h(1) FSR 05h IRP(4) RP1(4) RP0 TO PD Z DC C Indirect data memory address pointer (5) GPIO SCL SDA(5) GP5 GP4 GP3 GP2 GP1 GP0 11xx xxxx 11uu uuuu 06h -- Unimplemented -- -- 07h -- Unimplemented -- -- 08h -- Unimplemented -- -- -- Unimplemented 09h 0Ah(1,2) PCLATH -- 0Bh(1) INTCON 0Ch PIR1 Write Buffer for the upper 5 bits of the Program Counter -- -- ---0 0000 ---0 0000 -- -- GIE PEIE T0IE INTE GPIE T0IF INTF GPIF 0000 000x 0000 000u -- ADIF -- -- -- -- -- -- -0-- ---- -0-- ---- 0Dh -- Unimplemented -- -- 0Eh -- Unimplemented -- -- 0Fh -- Unimplemented -- -- 10h -- Unimplemented -- -- 11h -- Unimplemented -- -- 12h -- Unimplemented -- -- 13h -- Unimplemented -- -- 14h -- Unimplemented -- -- 15h -- Unimplemented -- -- 16h -- Unimplemented -- -- 17h -- Unimplemented -- -- 18h -- Unimplemented -- -- 19h -- Unimplemented -- -- 1Ah -- Unimplemented -- -- 1Bh -- Unimplemented -- -- 1Ch -- Unimplemented -- -- 1Dh -- 1Eh ADRES 1Fh ADCON0 Unimplemented A/D Result Register ADCS1 ADCS0 reserved CHS1 CHS0 GO/DONE reserved ADON -- -- xxxx xxxx uuuu uuuu 0000 0000 0000 0000 Legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented read as '0'. Shaded locations are unimplemented, read as `0'. Note 1: These registers can be addressed from either bank. 2: The upper byte of the program counter is not directly accessible. PCLATH is a holding register for the PC<12:8> whose contents are transferred to the upper byte of the program counter. 3: Other (non power-up) resets include external reset through MCLR and Watchdog Timer Reset. 4: The IRP and RP1 bits are reserved on the PIC12C67X; always maintain these bits clear. 5: The SCL (GP7) and SDA (GP6) bits are unimplemented on the PIC12C671/672 and read as '0'. 1999 Microchip Technology Inc. DS30561B-page 13 PIC12C67X TABLE 4-1: Address PIC12C67X SPECIAL FUNCTION REGISTER SUMMARY (CONT.) Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on Power-on Reset Value on all other Resets(3) 0000 0000 0000 0000 1111 1111 1111 1111 0000 0000 0000 0000 0001 1xxx 000q quuu xxxx xxxx uuuu uuuu Bank 1 80h(1) INDF 81h OPTION 82h(1) PCL (1) Addressing this location uses contents of FSR to address data memory (not a physical register) GPPU INTEDG T0CS T0SE PSA PS2 PS1 PS0 Program Counter's (PC) Least Significant Byte 83h STATUS 84h(1) FSR 85h TRIS IRP (4) RP1 (4) RP0 TO PD Z DC C Indirect data memory address pointer -- -- GPIO Data Direction Register --11 1111 --11 1111 86h -- Unimplemented -- -- 87h -- Unimplemented -- -- 88h -- Unimplemented -- -- -- Unimplemented 89h 8Ah(1,2) PCLATH -- 8Bh(1) INTCON 8Ch PIE1 8Dh -- 8Eh PCON 8Fh OSCCAL Write Buffer for the upper 5 bits of the PC -- -- ---0 0000 ---0 0000 -- -- GIE PEIE T0IE INTE GPIE T0IF INTF GPIF 0000 000x 0000 000u -- ADIE -- -- -- -- -- -- -0-- ---- -0-- ---- Unimplemented -- -- -- -- -- -- -- -- POR -- ---- --0- ---- --u- CAL3 CAL2 CAL1 CAL0 CALFST CALSLW -- -- 0111 00-- uuuu uu-- 90h -- Unimplemented -- -- 91h -- Unimplemented -- -- 92h -- Unimplemented -- -- 93h -- Unimplemented -- -- 94h -- Unimplemented -- -- 95h -- Unimplemented -- -- 96h -- Unimplemented -- -- 97h -- Unimplemented -- -- 98h -- Unimplemented -- -- 99h -- Unimplemented -- -- 9Ah -- Unimplemented -- -- 9Bh -- Unimplemented -- -- 9Ch -- Unimplemented -- -- 9Dh -- Unimplemented -- -- 9Eh -- Unimplemented -- -- ---- -000 ---- -000 9Fh ADCON1 -- -- -- -- -- PCFG2 PCFG1 PCFG0 Legend: x = unknown, u = unchanged, q = value depends on condition, - = unimplemented read as '0'. Shaded locations are unimplemented, read as `0'. Note 1: These registers can be addressed from either bank. 2: The upper byte of the program counter is not directly accessible. PCLATH is a holding register for the PC<12:8> whose contents are transferred to the upper byte of the program counter. 3: Other (non power-up) resets include external reset through MCLR and Watchdog Timer Reset. 4: The IRP and RP1 bits are reserved on the PIC12C67X; always maintain these bits clear. 5: The SCL (GP7) and SDA (GP6) bits are unimplemented on the PIC12C671/672 and read as '0'. DS30561B-page 14 1999 Microchip Technology Inc. PIC12C67X 4.2.2.1 STATUS REGISTER It is recommended, therefore, that only BCF, BSF, SWAPF and MOVWF instructions are used to alter the STATUS Register, because these instructions do not affect the Z, C or DC bits from the STATUS Register. For other instructions, not affecting any status bits, see the "Instruction Set Summary." The STATUS Register, shown in Register 4-1, contains the arithmetic status of the ALU, the RESET status and the bank select bits for data memory. The STATUS Register can be the destination for any instruction, as with any other register. If the STATUS Register is the destination for an instruction that affects the Z, DC or C bits, then the write to these three bits is disabled. These bits are set or cleared according to the device logic. Furthermore, the TO and PD bits are not writable. Therefore, the result of an instruction with the STATUS Register as destination may be different than intended. Note 1: Bits IRP and RP1 (STATUS<7:6>) are not used by the PIC12C67X and should be maintained clear. Use of these bits as general purpose R/W bits is NOT recommended, since this may affect upward compatibility with future products. 2: The C and DC bits operate as a borrow and digit borrow bit, respectively, in subtraction. See the SUBLW and SUBWF instructions for examples. For example, CLRF STATUS will clear the upper three bits and set the Z bit. This leaves the STATUS Register as 000u u1uu (where u = unchanged). REGISTER 4-1: Reserved Reserved IRP RP1 STATUS REGISTER (ADDRESS 03h, 83h) R/W-0 R-1 R-1 R/W-x R/W-x R/W-x RP0 TO PD Z DC C bit7 bit 7: bit0 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset IRP: Register Bank Select bit (used for indirect addressing) 1 = Bank 2, 3 (100h - 1FFh) 0 = Bank 0, 1 (00h - FFh) The IRP bit is reserved; always maintain this bit clear. bit 6-5: RP<1:0>: Register Bank Select bits (used for direct addressing) 11 = Bank 3 (180h - 1FFh) 10 = Bank 2 (100h - 17Fh) 01 = Bank 1 (80h - FFh) 00 = Bank 0 (00h - 7Fh) Each bank is 128 bytes. The RP1 bit is reserved; always maintain this bit clear. bit 4: TO: Time-out bit 1 = After power-up, CLRWDT instruction, or SLEEP instruction 0 = A WDT time-out occurred bit 3: PD: Power-down bit 1 = After power-up or by the CLRWDT instruction 0 = By execution of the SLEEP instruction bit 2: Z: Zero bit 1 = The result of an arithmetic or logic operation is zero 0 = The result of an arithmetic or logic operation is not zero bit 1: DC: Digit Carry/borrow bit (ADDWF, ADDLW,SUBLW,SUBWF instructions) (for borrow the polarity is reversed) 1 = A carry-out from the 4th low order bit of the result occurred 0 = No carry-out from the 4th low order bit of the result bit 0: C: Carry/borrow bit (ADDWF, ADDLW,SUBLW,SUBWF instructions) 1 = A carry-out from the most significant bit of the result occurred 0 = No carry-out from the most significant bit of the result occurred Note: For borrow the polarity is reversed. A subtraction is executed by adding the two's complement of the second operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high or low order bit of the source register. 1999 Microchip Technology Inc. DS30561B-page 15 PIC12C67X 4.2.2.2 OPTION REGISTER Note: The OPTION Register is a readable and writable register, which contains various control bits to configure the TMR0/WDT prescaler, the External INT Interrupt, TMR0 and the weak pull-ups on GPIO. REGISTER 4-2: To achieve a 1:1 prescaler assignment for the TMR0 register, assign the prescaler to the Watchdog Timer by setting bit PSA (OPTION<3>). OPTION REGISTER (ADDRESS 81h) R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 R/W-1 GPPU INTEDG T0CS T0SE PSA PS2 PS1 PS0 bit7 bit0 bit 7: GPPU: Weak Pull-up Enable 1 = Weak pull-ups disabled 0 = Weak pull-ups enabled (GP0, GP1, GP3) bit 6: INTEDG: Interrupt Edge 1 = Interrupt on rising edge of GP2/T0CKI/AN2/INT pin 0 = Interrupt on falling edge of GP2/T0CKI/AN2/INT pin bit 5: T0CS: TMR0 Clock Source Select bit 1 = Transition on GP2/T0CKI/AN2/INT pin 0 = Internal instruction cycle clock (CLKOUT) bit 4: T0SE: TMR0 Source Edge Select bit 1 = Increment on high-to-low transition on GP2/T0CKI/AN2/INT pin 0 = Increment on low-to-high transition on GP2/T0CKI/AN2/INT pin bit 3: PSA: Prescaler Assignment bit 1 = Prescaler is assigned to the WDT 0 = Prescaler is assigned to the Timer0 module R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset bit 2-0: PS<2:0>: Prescaler Rate Select bits Bit Value 000 001 010 011 100 101 110 111 DS30561B-page 16 TMR0 Rate 1:2 1:4 1:8 1 : 16 1 : 32 1 : 64 1 : 128 1 : 256 WDT Rate 1:1 1:2 1:4 1:8 1 : 16 1 : 32 1 : 64 1 : 128 1999 Microchip Technology Inc. PIC12C67X 4.2.2.3 INTCON REGISTER Note: The INTCON Register is a readable and writable register, which contains various enable and flag bits for the TMR0 Register overflow, GPIO port change and external GP2/INT pin interrupts. REGISTER 4-3: Interrupt flag bits get set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit, GIE (INTCON<7>). INTCON REGISTER (ADDRESS 0Bh, 8Bh) R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-0 R/W-x GIE PEIE T0IE INTE GPIE T0IF INTF GPIF bit7 bit0 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset bit 7: GIE: Global Interrupt Enable bit 1 = Enables all un-masked interrupts 0 = Disables all interrupts bit 6: PEIE: Peripheral Interrupt Enable bit 1 = Enables all un-masked peripheral interrupts 0 = Disables all peripheral interrupts bit 5: T0IE: TMR0 Overflow Interrupt Enable bit 1 = Enables the TMR0 interrupt 0 = Disables the TMR0 interrupt bit 4: INTE: INT External Interrupt Enable bit 1 = Enables the external interrupt on GP2/INT/T0CKI/AN2 pin 0 = Disables the external interrupt on GP2/INT/T0CKI/AN2 pin bit 3: GPIE: GPIO Interrupt on Change Enable bit 1 = Enables the GPIO Interrupt on Change 0 = Disables the GPIO Interrupt on Change bit 2: T0IF: TMR0 Overflow Interrupt Flag bit 1 = TMR0 register has overflowed (must be cleared in software) 0 = TMR0 register did not overflow bit 1: INTF: INT External Interrupt Flag bit 1 = The external interrupt on GP2/INT/T0CKI/AN2 pin occurred (must be cleared in software) 0 = The external interrupt on GP2/INT/T0CKI/AN2 pin did not occur bit 0: GPIF: GPIO Interrupt on Change Flag bit 1 = GP0, GP1 or GP3 pins changed state (must be cleared in software) 0 = Neither GP0, GP1 nor GP3 pins have changed state 1999 Microchip Technology Inc. DS30561B-page 17 PIC12C67X 4.2.2.4 PIE1 REGISTER Note: This register contains the individual enable bits for the Peripheral interrupts. REGISTER 4-4: Bit PEIE (INTCON<6>) must be set to enable any peripheral interrupt. PIE1 REGISTER (ADDRESS 8Ch) U-0 R/W-0 U-0 U-0 U-0 U-0 U-0 U-0 -- ADIE -- -- -- -- -- -- bit7 bit0 bit 7: Unimplemented: Read as '0' bit 6: ADIE: A/D Converter Interrupt Enable bit 1 = Enables the A/D interrupt 0 = Disables the A/D interrupt R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset bit 5-0: Unimplemented: Read as '0' DS30561B-page 18 1999 Microchip Technology Inc. PIC12C67X 4.2.2.5 PIR1 REGISTER Note: This register contains the individual flag bits for the Peripheral interrupts. REGISTER 4-5: Interrupt flag bits get set when an interrupt condition occurs, regardless of the state of its corresponding enable bit or the global enable bit, GIE (INTCON<7>). User software should ensure the appropriate interrupt flag bits are clear prior to enabling an interrupt. PIR1 REGISTER (ADDRESS 0Ch) U-0 R/W-0 U-0 U-0 U-0 U-0 U-0 U-0 -- ADIF -- -- -- -- -- -- bit7 bit0 bit 7: Unimplemented: Read as '0' bit 6: ADIF: A/D Converter Interrupt Flag bit 1 = An A/D conversion completed (must be cleared in software) 0 = The A/D conversion is not complete R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset bit 5-0: Unimplemented: Read as '0' 1999 Microchip Technology Inc. DS30561B-page 19 PIC12C67X 4.2.2.6 PCON REGISTER The Power Control (PCON) Register contains a flag bit to allow differentiation between a Power-on Reset (POR), an external MCLR Reset and a WDT Reset. REGISTER 4-6: PCON REGISTER (ADDRESS 8Eh) U-0 U-0 U-0 U-0 U-0 U-0 R/W-0 U-0 -- -- -- -- -- -- POR -- bit7 bit0 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset bit 7-2: Unimplemented: Read as '0' bit 1: POR: Power-on Reset Status bit 1 = No Power-on Reset occurred 0 = A Power-on Reset occurred (must be set in software after a Power-on Reset occurs) bit 0: Unimplemented: Read as '0' DS30561B-page 20 1999 Microchip Technology Inc. PIC12C67X 4.2.2.7 OSCCAL REGISTER The Oscillator Calibration (OSCCAL) Register is used to calibrate the internal 4 MHz oscillator. It contains four bits for fine calibration and two other bits to either increase or decrease frequency. REGISTER 4-7: OSCCAL REGISTER (ADDRESS 8Fh) R/W-0 R/W-1 R/W-1 R/W-1 R/W-0 R/W-0 U-0 U-0 CAL3 CAL2 CAL1 CAL0 CALFST CALSLW -- -- bit7 bit0 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset bit 7-4: CAL<3:0>: Fine Calibration bit 3: CALFST: Calibration Fast 1 = Increase frequency 0 = No change bit 2: CALSLW: Calibration Slow 1 = Decrease frequency 0 = No change bit 1-0: Unimplemented: Read as '0' Note: If CALFST = 1 and CALSLW = 1, CALFST has precedence. 1999 Microchip Technology Inc. DS30561B-page 21 PIC12C67X 4.3 PCL and PCLATH 4.3.2 The Program Counter (PC) is 13-bits wide. The low byte comes from the PCL Register, which is a readable and writable register. The high byte (PC<12:8>) is not directly readable or writable and comes from PCLATH. On any reset, the PC is cleared. Figure 4-3 shows the two situations for the loading of the PC. The upper example in the figure shows how the PC is loaded on a write to PCL (PCLATH<4:0> PCH). The lower example in the figure shows how the PC is loaded during a CALL or GOTO instruction (PCLATH<4:3> PCH). FIGURE 4-3: LOADING OF PC IN DIFFERENT SITUATIONS PCH PCL 12 8 7 0 PC 5 8 PCLATH<4:0> Instruction with PCL as Destination The PIC12C67X family has an 8-level deep x 13-bit wide hardware stack. The stack space is not part of either program or data space and the stack pointer is not readable or writable. The PC is PUSHed onto the stack when a CALL instruction is executed or an interrupt causes a branch. The stack is POPed in the event of a RETURN, RETLW or a RETFIE instruction execution. PCLATH is not affected by a PUSH or POP operation. The stack operates as a circular buffer. This means that after the stack has been PUSHed eight times, the ninth push overwrites the value that was stored from the first push. The tenth push overwrites the second push (and so on). Note 1: There are no status bits to indicate stack overflow or stack underflow conditions. 2: There are no instructions/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 address. ALU result PCLATH PCH 12 11 10 PCL 8 0 7 PC GOTO, CALL 2 PCLATH<4:3> 11 Opcode <10:0> PCLATH 4.3.1 COMPUTED GOTO STACK 4.4 Program Memory Paging The PIC12C67X ignores both paging bits PCLATH<4:3>, which are used to access program memory when more than one page is available. The use of PCLATH<4:3> as general purpose read/write bits for the PIC12C67X is not recommended since this may affect upward compatibility with future products. A Computed GOTO is accomplished by adding an offset to the program counter (ADDWF PCL). When doing a table read using a computed GOTO method, care should be exercised if the table location crosses a PCL memory boundary (each 256 byte block). Refer to the application note "Implementing a Table Read" (AN556). DS30561B-page 22 1999 Microchip Technology Inc. PIC12C67X 4.5 Indirect Addressing, INDF and FSR Registers EXAMPLE 4-1: The INDF Register is not a physical register. Addressing the INDF Register will cause indirect addressing. movlw movwf clrf incf btfss goto NEXT Any instruction using the INDF register actually accesses the register pointed to by the File Select Register, FSR. Reading the INDF Register itself indirectly (FSR = '0') will read 00h. Writing to the INDF Register indirectly results in a no-operation (although status bits may be affected). An effective 9-bit address is obtained by concatenating the 8-bit FSR Register and the IRP bit (STATUS<7>), as shown in Figure 4-4. However, IRP is not used in the PIC12C67X. INDIRECT ADDRESSING 0x20 FSR INDF FSR,F FSR,4 NEXT ;initialize pointer ;to RAM ;clear INDF register ;inc pointer ;all done? ;no clear next CONTINUE : ;yes continue A simple program to clear RAM locations 20h-2Fh using indirect addressing is shown in Example 4-1. FIGURE 4-4: DIRECT/INDIRECT ADDRESSING Direct Addressing (1) from opcode RP1 RP0 6 bank select location select Indirect Addressing 0 IRP (1) 7 bank select 00 01 10 FSR register 0 location select 11 00h 180h not used Data Memory 7Fh 1FFh Bank 0 Bank 1 Bank 2 Bank 3 For register file map detail see Figure 4-2. Note 1: The RP1 and IRP bits are reserved; always maintain these bits clear. 1999 Microchip Technology Inc. DS30561B-page 23 PIC12C67X NOTES: DS30561B-page 24 1999 Microchip Technology Inc. PIC12C67X 5.0 I/O PORT As with any other register, the I/O register can be written and read under program control. However, read instructions (i.e., MOVF GPIO,W) always read the I/O pins independent of the pin's input/output modes. On RESET, all I/O ports are defined as input (inputs are at hi-impedance), since the I/O control registers are all set. 5.1 GPIO GPIO is an 8-bit I/O register. Only the low order 6 bits are used (GP<5:0>). Bits 6 and 7 (SDA and SCL, respectively) are used by the EEPROM peripheral on the PIC12CE673/674. Refer to Section 6.0 and Appendix B for use of SDA and SCL. Please note that GP3 is an input only pin. The configuration word can set several I/O's to alternate functions. When acting as alternate functions, the pins will read as `0' during port read. Pins GP0, GP1 and GP3 can be configured with weak pull-ups and also with interrupt-on-change. The interrupt on change and weak pull-up functions are not pin selectable. If pin 4, (GP3), is configured as MCLR, a weak pull-up is always on. Interrupt-on-change for this pin is not set and GP3 will read as '0'. Interrupt-onchange is enabled by setting bit GPIE, INTCON<3>. Note that external oscillator use overrides the GPIO functions on GP4 and GP5. 5.2 5.3 I/O Interfacing The equivalent circuit for an I/O port pin is shown in Figure 5-1 through Figure 5-5. All port pins, except GP3, which is input only, may be used for both input and output operations. For input operations, these ports are non-latching. Any input must be present until read by an input instruction (i.e., MOVF GPIO,W). The outputs are latched and remain unchanged until the output latch is rewritten. To use a port pin as output, the corresponding direction control bit in TRIS must be cleared (= 0). For use as an input, the corresponding TRIS bit must be set. Any I/O pin (except GP3) can be programmed individually as input or output. Port pins GP6 (SDA) and GP7 (SCL) are used for the serial EEPROM interface on the PIC12CE673/674. These port pins are not available externally on the package. Users should avoid writing to pins GP6 (SDA) and GP7 (SCL) when not communicating with the serial EEPROM memory. Please see Section 6.0, EEPROM Peripheral Operation, for information on serial EEPROM communication. Note: On a Power-on Reset, GP0, GP1, GP2 and GP4 are configured as analog inputs and read as '0'. TRIS Register This register controls the data direction for GPIO. A '1' from a TRIS Register bit puts the corresponding output driver in a hi-impedance mode. A '0' puts the contents of the output data latch on the selected pins, enabling the output buffer. The exceptions are GP3, which is input only and its TRIS bit will always read as '1', while GP6 and GP7 TRIS bits will read as '0'. Note: A read of the ports reads the pins, not the output data latches. That is, if an output driver on a pin is enabled and driven high, but the external system is holding it low, a read of the port will indicate that the pin is low. Upon reset, the TRIS Register is all '1's, making all pins inputs. TRIS for pins GP4 and GP5 is forced to a '1' where appropriate. Writes to TRIS <5:4> will have an effect in EXTRC and INTRC oscillator modes only. When GP4 is configured as CLKOUT, changes to TRIS<4> will have no effect. 1999 Microchip Technology Inc. DS30561B-page 25 PIC12C67X FIGURE 5-1: BLOCK DIAGRAM OF GP0/AN0 AND GP1/AN1/VREF PIN GPPU Data Bus WR PORT D Q CK Q VDD VDD P P VDD I/O Pin Data Latch N WR TRIS D Q CK Q VSS VSS TRIS Latch Analog Input Mode TTL Input Buffer RD TRIS Q D EN RD PORT GP0/INT(1) and GP1/INT(1) To A/D Converter Note 1: Wake-up on pin change interrupts for GP0 and GP1. DS30561B-page 26 1999 Microchip Technology Inc. PIC12C67X FIGURE 5-2: BLOCK DIAGRAM OF GP2/T0CKI/AN2/INT PIN Data Bus WR PORT D Q CK Q VDD VDD P I/O Pin Data Latch N WR TRIS D Q CK Q VSS VSS TRIS Latch Analog Input Mode Schmitt Trigger Input Buffer RD TRIS Q D EN RD PORT TMR0 Clock Input GP2/INT To A/D Converter 1999 Microchip Technology Inc. DS30561B-page 27 PIC12C67X FIGURE 5-3: BLOCK DIAGRAM OF GP3/MCLR/VPP PIN VDD GPPU P MCLREN Input Pin VSS MCLR Schmitt Trigger Input Buffer Program Mode HV Detect TTL Input Buffer Data Bus Q D EN RD PORT RD TRIS VSS GP3/INT(1) Note 1: Wake-up on pin change interrupt for GP3. DS30561B-page 28 1999 Microchip Technology Inc. PIC12C67X FIGURE 5-4: BLOCK DIAGRAM OF GP4/OSC2/AN3/CLKOUT PIN INTRC or EXTRC w/ CLKOUT CLKOUT (FOSC/4) 1 0 From OSC1 Data Bus D WR PORT CK Q VDD Q Oscillator Circuit VDD P I/O Pin Data Latch N VSS WR TRIS D Q CK Q INTRC/ EXTRC VSS INTRC or EXTRC w/o CLKOUT TRIS Latch Analog Input Mode TTL Input Buffer RD TRIS Q D EN RD PORT To A/D Converter 1999 Microchip Technology Inc. DS30561B-page 29 PIC12C67X FIGURE 5-5: BLOCK DIAGRAM OF GP5/OSC1/CLKIN PIN To OSC2 Oscillator Circuit Data Bus WR PORT D Q EN Q VDD VDD P Data Latch I/O Pin N WR TRIS D Q EN Q INTRC VSS VSS TRIS Latch INTRC TTL Input Buffer RD TRIS Q D EN RD PORT DS30561B-page 30 1999 Microchip Technology Inc. PIC12C67X TABLE 5-1: Address SUMMARY OF PORT REGISTERS Name Bit 7 Bit 6 -- -- INTEDG 85h TRIS 81h OPTION GPPU 03h STATUS IRP (1) 05h GPIO SCL(2) Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Value on Power-on Reset Value on all other Resets --11 1111 --11 1111 PS0 1111 1111 1111 1111 Bit 0 GPIO Data Direction Register T0CS T0SE PSA PS2 PS1 (1) RP0 TO PD Z DC C 0001 1xxx 000q quuu SDA(2) GP5 GP4 GP3 GP2 GP1 GP0 11xx xxxx 11uu uuuu RP1 Legend: Shaded cells not used by Port Registers, read as `0', -- = unimplemented, read as '0', x = unknown, u = unchanged, q = see tables in Section 9.4 for possible values. Note 1: The IRP and RP1 bits are reserved on the PIC12C67X; always maintain these bits clear. 2: The SCL and SDA bits are unimplemented on the PIC12C671 and PIC12C672. 5.4 I/O Programming Considerations 5.4.1 BI-DIRECTIONAL I/O PORTS Any instruction which writes, operates internally as a read followed by a write operation. The BCF and BSF instructions, for example, 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 GPIO will cause all eight bits of GPIO to be read into the CPU. Then the BSF operation takes place on bit5 and GPIO is written to the output latches. If another bit of GPIO is used as a bi-directional I/O pin (i.e., bit0) and it is defined as an input at this time, the input signal present on the pin itself would be read into the CPU and rewritten to the data latch of this particular pin, overwriting the previous content. As long as the pin stays in the input mode, no problem occurs. However, if bit0 is switched to an output, the content of the data latch may now be unknown. Reading the port register 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 (i.e., BCF, BSF, etc.) on a port, the value of the port pins is read, the desired operation is done to this value, and this value is then written to the port latch. 1999 Microchip Technology Inc. Example 5-1 shows the effect of two sequential readmodify-write instructions on an I/O port. EXAMPLE 5-1: READ-MODIFY-WRITE INSTRUCTIONS ON AN I/O PORT ;Initial GPIO Settings ; GPIO<5:3> Inputs ; GPIO<2:0> Outputs ; ; GPIO latch GPIO pins ; ---------- ---------BCF GPIO, 5 ;--01 -ppp --11 pppp BCF GPIO, 4 ;--10 -ppp --11 pppp MOVLW 007h ; TRIS GPIO ;--10 -ppp --10 pppp ; ;Note that the user may have expected the pin ;values to be --00 pppp. The 2nd BCF caused ;GP5 to be latched as the pin value (High). A pin actively outputting a Low or High should not be driven from external devices at the same time in order to change the level on this pin ("wired-or", "wired-and"). The resulting high output currents may damage the chip. DS30561B-page 31 PIC12C67X NOTES: DS30561B-page 32 1999 Microchip Technology Inc. PIC12C67X 6.0 EEPROM PERIPHERAL OPERATION The PIC12CE673 and PIC12CE674 each have 16 bytes of EEPROM data memory. The EEPROM memory has an endurance of 1,000,000 erase/write cycles and a data retention of greater than 40 years. The EEPROM data memory supports a bi-directional 2-wire bus and data transmission protocol. These two-wires are serial data (SDA) and serial clock (SCL), that are mapped to bit6 and bit7, respectively, of the GPIO register (SFR 06h). Unlike the GP0-GP5 that are connected to the I/O pins, SDA and SCL are only connected to the internal EEPROM peripheral. For most applications, all that is required is calls to the following functions: ; Byte_Write: Byte write routine ; Inputs: EEPROM Address EEADDR ; EEPROM Data EEDATA ; Outputs: Return 01 in W if OK, else return 00 in W ; ; Read_Current: Read EEPROM at address currently held by EE device. ; Inputs: NONE ; Outputs: EEPROM Data EEDATA ; Return 01 in W if OK, else return 00 in W ; ; Read_Random: Read EEPROM byte at supplied address ; Inputs: EEPROM Address EEADDR ; Outputs: EEPROM Data EEDATA ; Return 01 in W if OK, else return 00 in W The code for these functions is available on our web site (www.microchip.com). The code will be accessed by either including the source code FL67XINC.ASM or by linking FLASH67X.ASM. FLASH67X.INC provides external definition to the calling program. 6.0.1 SERIAL DATA SDA is a bi-directional pin used to transfer addresses and data into and data out of the device. 6.1 Bus Characteristics The following bus protocol is to be used with the EEPROM data memory. In this section, the term "processor" is used to denote the portion of the PIC12C67X that interfaces to the EEPROM via software. * Data transfer may be initiated only when the bus is not busy. During data transfer, the data line must remain stable whenever the clock line is HIGH. Changes in the data line while the clock line is HIGH will be interpreted as a START or STOP condition. Accordingly, the following bus conditions have been defined (Figure 6-3). 6.1.1 BUS NOT BUSY (A) Both data and clock lines remain HIGH. 6.1.2 START DATA TRANSFER (B) A HIGH to LOW transition of the SDA line while the clock (SCL) is HIGH determines a START condition. All commands must be preceded by a START condition. 6.1.3 STOP DATA TRANSFER (C) A LOW to HIGH transition of the SDA line while the clock (SCL) is HIGH determines a STOP condition. All operations must be ended with a STOP condition. 6.1.4 DATA VALID (D) The state of the data line represents valid data when, after a START condition, the data line is stable for the duration of the HIGH period of the clock signal. The data on the line must be changed during the LOW period of the clock signal. There is one bit of data per clock pulse. Each data transfer is initiated with a START condition and terminated with a STOP condition. The number of the data bytes transferred between the START and STOP conditions is determined by the available data EEPROM space. For normal data transfer, SDA is allowed to change only during SCL low. Changes during SCL high are reserved for indicating the START and STOP conditions. 6.0.2 SERIAL CLOCK This SCL signal is used to synchronize the data transfer from and to the EEPROM. 1999 Microchip Technology Inc. DS30561B-page 33 PIC12C67X 6.1.5 ACKNOWLEDGE The EEPROM, when addressed, will generate an acknowledge after the reception of each byte. The processor must generate an extra clock pulse which is associated with this acknowledge bit. Note: Acknowledge bits are not generated if an internal programming cycle is in progress. FIGURE 6-1: The device that acknowledges has to pull down the SDA line during the acknowledge clock pulse in such a way that the SDA line is stable LOW during the HIGH period of the acknowledge related clock pulse. Of course, setup and hold times must be taken into account. The processor must signal an end of data to the EEPROM by not generating an acknowledge bit on the last byte that has been clocked out of the EEPROM. In this case, the EEPROM must leave the data line HIGH to enable the processor to generate the STOP condition (Figure 6-4). BLOCK DIAGRAM OF GPIO6 (SDA LINE) VDD Reset To EEPROM SDA Pad D Data Bus Write GPIO EN CK P Q Output Latch Q D Schmitt Trigger EN CK Input Latch ltchpin Read GPIO FIGURE 6-2: BLOCK DIAGRAM OF GPIO7 (SCL LINE) VDD D Data Bus Write GPIO CK P EN Q Output Latch Q N D Schmitt Trigger EN CK Read GPIO DS30561B-page 34 To EEPROM SCL Pad ltchpin 1999 Microchip Technology Inc. PIC12C67X FIGURE 6-3: SCL (A) DATA TRANSFER SEQUENCE ON THE SERIAL BUS (B) (C) (D) START CONDITION ADDRESS OR ACKNOWLEDGE VALID (C) (A) SDA FIGURE 6-4: STOP CONDITION DATA ALLOWED TO CHANGE ACKNOWLEDGE TIMING Acknowledge Bit SCL 1 2 SDA 3 4 5 6 7 8 9 1 Device Addressing After generating a START condition, the processor transmits a control byte consisting of a EEPROM address and a Read/Write bit that indicates what type of operation is to be performed. The EEPROM address consists of a 4-bit device code (1010) followed by three don't care bits. The last bit of the control byte determines the operation to be performed. When set to a one, a read operation is selected, and when set to a zero, a write operation is selected (Figure 6-5). The bus is monitored for its corresponding EEPROM address all the time. It generates an acknowledge bit if the EEPROM address was true and it is not in a programming mode. 1999 Microchip Technology Inc. 3 Data from transmitter Data from transmitter Receiver must release the SDA line at this point so the Transmitter can continue sending data. Transmitter must release the SDA line at this point allowing the Receiver to pull the SDA line low to acknowledge the previous eight bits of data. 6.2 2 FIGURE 6-5: CONTROL BYTE FORMAT Read/Write Bit Device Select Bits S 1 0 1 Don't Care Bits 0 X X X R/W ACK EEPROM Address Start Condition Acknowledge Condition DS30561B-page 35 PIC12C67X 6.3 Write Operations 6.4 6.3.1 BYTE WRITE Since the EEPROM will not acknowledge during a write cycle, this can be used to determine when the cycle is complete (this feature can be used to maximize bus throughput). Once the stop condition for a write command has been issued from the processor, the device initiates the internally timed write cycle. ACK polling can be initiated immediately. This involves the processor sending a start condition followed by the control byte for a write command (R/W = 0). If the device is still busy with the write cycle, then no ACK will be returned. If no ACK is returned, then the start bit and control byte must be re-sent. If the cycle is complete, then the device will return the ACK and the processor can then proceed with the next read or write command. (See Figure 6-6 for flow diagram.) Following the start signal from the processor, the device code (4 bits), the don't care bits (3 bits), and the R/W bit (which is a logic low) are placed onto the bus by the processor. This indicates to the addressed EEPROM that a byte with a word address will follow after it has generated an acknowledge bit during the ninth clock cycle. Therefore, the next byte transmitted by the processor is the word address and will be written into the address pointer. Only the lower four address bits are used by the device, and the upper four bits are don't cares. If the address byte is acknowledged, the processor will then transmit the data word to be written into the addressed memory location. The memory acknowledges again and the processor generates a stop condition. This initiates the internal write cycle, and during this time will not generate acknowledge signals. After a byte write command, the internal address counter will not be incremented and will point to the same address location that was just written. If a stop bit sequence is transmitted to the device at any point in the write command sequence before the entire sequence is complete, then the command will abort and no data will be written. If more than 8 data bits are transmitted before the stop bit sequence is sent, then the device will clear the previously loaded byte and begin loading the data buffer again. If more than one data byte is transmitted to the device and a stop bit is sent before a full eight data bits have been transmitted, then the write command will abort and no data will be written. The EEPROM memory employs a VCC threshold detector circuit, which disables the internal erase/write logic if the VCC is below minimum VDD. Byte write operations must be preceded and immediately followed by a bus not busy bus cycle where both SDA and SCL are held high. (See Figure 6-7 for Byte Write operation.) Acknowledge Polling FIGURE 6-6: ACKNOWLEDGE POLLING FLOW Send Write Command Send Stop Condition to Initiate Write Cycle Send Start Send Control Byte with R/W = 0 Did EEPROM Acknowledge (ACK = 0)? NO YES Next Operation FIGURE 6-7: BYTE WRITE S T A R T SDA LINE ACTIVITY S CONTROL BYTE 1 0 1 0 X X WORD ADDRESS X X 0 A C K X X S T O P DATA P X A C K A C K X = Don't Care Bit DS30561B-page 36 1999 Microchip Technology Inc. PIC12C67X 6.5 Read Operations address is sent, the processor generates a start condition following the acknowledge. This terminates the write operation, but not before the internal address pointer is set. Then the processor issues the control byte again, but with the R/W bit set to a one. The EEPROM will then issue an acknowledge and transmits the 8-bit data word. The processor will not acknowledge the transfer, but does generate a stop condition and the EEPROM discontinues transmission (Figure 6-9). After this command, the internal address counter will point to the address location following the one that was just read. Read operations are initiated in the same way as write operations with the exception that the R/W bit of the EEPROM address is set to one. There are three basic types of read operations; current address read, random read and sequential read. 6.5.1 CURRENT ADDRESS READ The EEPROM contains an address counter that maintains the address of the last word accessed, internally incremented by one. Therefore, if the previous read access was to address n, the next current address read operation would access data from address n + 1. Upon receipt of the EEPROM address with the R/W bit set to one, the EEPROM issues an acknowledge and transmits the 8-bit data word. The processor will not acknowledge the transfer, but does generate a stop condition and the EEPROM discontinues transmission (Figure 6-8). 6.5.2 6.5.3 Sequential reads are initiated in the same way as a random read, except that after the device transmits the first data byte, the processor issues an acknowledge as opposed to a stop condition in a random read. This directs the EEPROM to transmit the next sequentially addressed 8-bit word (Figure 6-10). RANDOM READ To provide sequential reads, the EEPROM contains an internal address pointer, which is incremented by one at the completion of each read operation. This address pointer allows the entire memory contents to be serially read during one operation. Random read operations allow the processor to access any memory location in a random manner. To perform this type of read operation, first the word address must be set. This is done by sending the word address to the EEPROM as part of a write operation. After the word FIGURE 6-8: SEQUENTIAL READ CURRENT ADDRESS READ S T A R T SDA LINE ACTIVITY S T O P CONTROL BYTE S 1 0 1 0 X XX 1 P A C K N O DATA A C K X = Don't Care Bit FIGURE 6-9: RANDOM READ S T A R T CONTROL BYTE X X X X S 1 0 1 0 X X X 0 SDA LINE ACTIVITY S T A R T WORD ADDRESS (n) P S 1 0 1 0 X X X 1 A C K A C K S T O P CONTROL BYTE A C K DATA (n) N O A C K X = Don't Care Bit FIGURE 6-10: SEQUENTIAL READ CONTROL BYTE SDA LINE ACTIVITY DATA n DATA n + 1 DATA n + 2 S T O P DATA n + X P A C K 1999 Microchip Technology Inc. A C K A C K A C K N O A C K DS30561B-page 37 PIC12C67X NOTES: DS30561B-page 38 1999 Microchip Technology Inc. PIC12C67X 7.0 TIMER0 MODULE (OPTION<4>). Clearing bit T0SE selects the rising edge. Restrictions on the external clock input are discussed in detail in Section 7.2. The Timer0 module timer/counter has the following features: * * * * * * The prescaler is mutually exclusively shared between the Timer0 module and the Watchdog Timer. The prescaler assignment is controlled in software by control bit PSA (OPTION<3>). Clearing bit PSA will assign the prescaler to the Timer0 module. The prescaler is not readable or writable. When the prescaler is assigned to the Timer0 module, prescale values of 1:2, 1:4, ..., 1:256 are selectable. Section 7.3 details the operation of the prescaler. 8-bit timer/counter Readable and writable 8-bit software programmable prescaler Internal or external clock select Interrupt on overflow from FFh to 00h Edge select for external clock Figure 7-1 is a simplified block diagram of the Timer0 module. 7.1 Timer mode is selected by clearing bit T0CS (OPTION<5>). In timer mode, the Timer0 module will increment every instruction cycle (without prescaler). If the TMR0 register is written, the increment is inhibited for the following two instruction cycles (Figure 7-2 and Figure 7-3). The user can work around this by writing an adjusted value to the TMR0 register. The TMR0 interrupt is generated when the TMR0 register overflows from FFh to 00h. This overflow sets bit T0IF (INTCON<2>). The interrupt can be masked by clearing bit T0IE (INTCON<5>). Bit T0IF must be cleared in software by the Timer0 module interrupt service routine before re-enabling this interrupt. The TMR0 interrupt cannot awaken the processor from SLEEP, since the timer is shut off during SLEEP. See Figure 7-4 for Timer0 interrupt timing. Counter mode is selected by setting bit T0CS (OPTION<5>). In counter mode, Timer0 will increment either on every rising or falling edge of pin RA4/T0CKI. The incrementing edge is determined by the bit T0SE FIGURE 7-1: Timer0 Interrupt TIMER0 BLOCK DIAGRAM Data Bus FOSC/4 0 8 1 Sync with Internal clocks 1 Programmable Prescaler GP2/TOCKI/ AN2/INT 0 TMR0 (2 TCY delay) TOSE 3 Set interrupt flag bit T0IF on overflow PSA PS<2:0> TOCS Note 1: TOCS, TOSE, PSA, PS<2:0> (OPTION<5:0>). 2: The prescaler is shared with Watchdog Timer (refer to Figure 7-6 for detailed block diagram). FIGURE 7-2: PC (Program Counter) TIMER0 TIMING: INTERNAL CLOCK/NO PRESCALE Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 PC-1 Instruction Fetch TMR0 PC PC+1 PC+2 PC+3 PC+4 PC+5 PC+6 MOVWF TMR0 MOVF TMR0,WMOVF TMR0,WMOVF TMR0,WMOVF TMR0,WMOVF TMR0,W T0 T0+1 Instruction Executed 1999 Microchip Technology Inc. T0+2 NT0 NT0 Write TMR0 executed Read TMR0 reads NT0 Read TMR0 reads NT0 NT0 Read TMR0 reads NT0 NT0+1 NT0+2 T0 Read TMR0 Read TMR0 reads NT0 + 1 reads NT0 + 2 DS30561B-page 39 PIC12C67X FIGURE 7-3: TIMER0 TIMING: INTERNAL CLOCK/PRESCALE 1:2 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 PC (Program Counter) PC-1 PC PC+1 PC+2 PC+3 PC+4 PC+5 PC+6 MOVWF TMR0 MOVF TMR0,WMOVF TMR0,WMOVF TMR0,WMOVF TMR0,WMOVF TMR0,W Instruction Fetch T0 TMR0 T0+1 Instruction Execute Write TMR0 executed FIGURE 7-4: NT0+1 NT0 Read TMR0 reads NT0 Read TMR0 reads NT0 Read TMR0 reads NT0 Read TMR0 reads NT0 Read TMR0 reads NT0 + 1 TIMER0 INTERRUPT TIMING Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 CLKOUT(3) Timer0 FEh T0IF bit (INTCON<2>) FFh 00h 01h 02h 1 1 Interrupt Latency(2) GIE bit (INTCON<7>) INSTRUCTION FLOW PC PC Instruction fetched Inst (PC) Instruction executed Inst (PC-1) Note 1: PC +1 PC +1 Inst (PC+1) Inst (PC) Dummy cycle 0004h 0005h Inst (0004h) Inst (0005h) Dummy cycle Inst (0004h) Interrupt flag bit T0IF is sampled here (every Q1). 2: Interrupt latency = 3TCY where TCY = instruction cycle time. 3: CLKOUT is available only in the INTRC and EXTRC oscillator modes. DS30561B-page 40 1999 Microchip Technology Inc. PIC12C67X 7.2 Using Timer0 with an External Clock caler, so that the prescaler output is symmetrical. For the external clock to meet the sampling requirement, the ripple-counter must be taken into account. Therefore, it is necessary for T0CKI to have a period of at least 4TOSC (and a small RC delay of 40 ns) divided by the prescaler value. The only requirement on T0CKI high and low time is that they do not violate the minimum pulse width requirement of 10 ns. Refer to parameters 40, 41 and 42 in the electrical specification of the desired device. When an external clock input is used for Timer0, it must meet certain requirements. The requirements ensure the external clock can be synchronized with the internal phase clock (TOSC). Also, there is a delay in the actual incrementing of Timer0 after synchronization. 7.2.1 EXTERNAL CLOCK SYNCHRONIZATION When no prescaler is used, the external clock input is used as the clock source. The synchronization of T0CKI with the internal phase clocks is accomplished by sampling the prescaler output on the Q2 and Q4 cycles of the internal phase clocks (Figure 7-5). Therefore, it is necessary for T0CKI to be high for at least 2TOSC (and a small RC delay of 20 ns) and low for at least 2TOSC (and a small RC delay of 20 ns). Refer to the electrical specification of the desired device. 7.2.2 TMR0 INCREMENT DELAY 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 the Timer0 module is actually incremented. Figure 7-5 shows the delay from the external clock edge to the timer incrementing. When a prescaler is used, the external clock input is divided by the asynchronous ripple-counter type pres- FIGURE 7-5: TIMER0 TIMING WITH EXTERNAL CLOCK Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Small pulse misses sampling External Clock Input or Prescaler output(2) (1) External Clock/Prescaler Output after sampling (3) Increment Timer0 (Q4) Timer0 Note 1: T0 T0 + 1 T0 + 2 Delay from clock input change to Timer0 increment is 3TOSC to 7TOSC. (Duration of Q = TOSC). Therefore, the error in measuring the interval between two edges on Timer0 input = 4TOSC max. 2: External clock if no prescaler selected; prescaler output otherwise. 3: The arrows indicate the points in time where sampling occurs. 1999 Microchip Technology Inc. DS30561B-page 41 PIC12C67X 7.3 The PSA and PS<2:0> bits (OPTION<3:0>) determine the prescaler assignment and prescale ratio. Prescaler An 8-bit counter is available as a prescaler for the Timer0 module, or as a postscaler for the Watchdog Timer, respectively (Figure 7-6). For simplicity, this counter is being referred to as "prescaler" throughout this data sheet. Note that there is only one prescaler available which is mutually exclusively shared between the Timer0 module and the Watchdog Timer. Thus, a prescaler assignment for the Timer0 module means that there is no prescaler for the Watchdog Timer, and vice-versa. FIGURE 7-6: When assigned to the Timer0 module, all instructions writing to the TMR0 register (i.e., CLRF 1, MOVWF 1, BSF 1,x...., etc.) will clear the prescaler. When assigned to WDT, a CLRWDT instruction will clear the prescaler along with the Watchdog Timer. The prescaler is not readable or writable. BLOCK DIAGRAM OF THE TIMER0/WDT PRESCALER Data Bus CLKOUT (= FOSC/4) 0 GP2/T0CKI/ AN2/INT 8 M U X 1 M U X 0 1 SYNC 2 Cycles TMR0 reg T0SE T0CS 0 Watchdog Timer 1 M U X Set flag bit T0IF on Overflow PSA 8-bit Prescaler 8 8 - to - 1MUX PS<2:0> PSA WDT Enable bit 1 0 MUX PSA WDT Time-out Note: T0CS, T0SE, PSA, PS<2:0> are (OPTION<5:0>). DS30561B-page 42 1999 Microchip Technology Inc. PIC12C67X 7.3.1 SWITCHING PRESCALER ASSIGNMENT To change prescaler from the WDT to the Timer0 module, use the sequence shown in Example 7-2. The prescaler assignment is fully under software control, (i.e., it can be changed "on-the-fly" during program execution). Note: To avoid an unintended device RESET, the following instruction sequence (shown in Example 7-1) must be executed when changing the prescaler assignment from Timer0 to the WDT. This sequence must be followed even if the WDT is disabled. EXAMPLE 7-1: BCF CLRF BSF CLRWDT MOVLW MOVWF BCF EXAMPLE 7-2: BSF MOVLW MOVWF BCF ;Clear WDT and ;prescaler STATUS, RP0 ;Bank 1 b'xxxx0xxx' ;Select TMR0, new ;prescale value and OPTION_REG ;clock source STATUS, RP0 ;Bank 0 CHANGING PRESCALER (TIMER0WDT) STATUS, RP0 TMR0 STATUS, RP0 b'xxxx1xxx' OPTION_REG STATUS, RP0 TABLE 7-1: CLRWDT CHANGING PRESCALER (WDTTIMER0) ;Bank 0 ;Clear TMR0 & Prescaler ;Bank 1 ;Clears WDT ;Select new prescale ;value & WDT ;Bank 0 REGISTERS ASSOCIATED WITH TIMER0 Address Name 01h TMR0 0Bh/8Bh INTCON 81h OPTION 85h TRIS Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Timer0 module's register GIE PEIE GPPU INTEDG -- -- T0IE INTE GPIE T0IF INTF GPIF Value on POR Value on all other Resets xxxx xxxx uuuu uuuu 0000 000x 0000 000u T0CS T0SE PSA PS2 PS1 PS0 1111 1111 1111 1111 TRIS5 TRIS4 TRIS3 TRIS2 TRIS1 TRIS0 --11 1111 --11 1111 Legend: x = unknown, u = unchanged, - = unimplemented locations read as '0'. Shaded cells are not used by Timer0. 1999 Microchip Technology Inc. DS30561B-page 43 PIC12C67X NOTES: DS30561B-page 44 1999 Microchip Technology Inc. PIC12C67X 8.0 ANALOG-TO-DIGITAL CONVERTER (A/D) MODULE The Analog-To-Digital (A/D) converter module has four analog inputs. The A/D allows conversion of an analog input signal to a corresponding 8-bit digital number (refer to Application Note AN546 for use of A/D Converter). The output of the sample and hold is the input into the converter, which generates the result via successive approximation. The analog reference voltage is software selectable to either the device's positive supply voltage (VDD) or the voltage level on the GP1/AN1/VREF pin. The A/D converter has a unique feature of being able to operate while the device is in SLEEP mode. The ADCON0 Register, shown in Figure 8-1, controls the operation of the A/D module. The ADCON1 Register, shown in Figure 8-2, configures the functions of the port pins. The port pins can be configured as analog inputs (GP1 can also be a voltage reference) or as digital I/O. Note 1: If the port pins are configured as analog inputs (reset condition), reading the port (MOVF GPIO,W) results in reading '0's. 2: Changing ADCON1 Register can cause the GPIF and INTF flags to be set in the INTCON Register. These interrupts should be disabled prior to modifying ADCON1. The A/D module has three registers. These registers are: * A/D Result Register (ADRES) * A/D Control Register 0 (ADCON0) * A/D Control Register 1 (ADCON1) REGISTER 8-1: ADCON0 REGISTER (ADDRESS 1Fh) R/W-0 R/W-0 R/W-0 ADCS1 ADCS0 reserved bit7 R/W-0 CHS1 R/W-0 CHS0 R/W-0 R/W-0 GO/DONE reserved R/W-0 ADON bit0 R = Readable bit W = Writable bit U = Unimplemented bit, read as `0' - n = Value at POR reset bit 7-6: ADCS<1:0>: A/D Conversion Clock Select bits 00 = FOSC/2 01 = FOSC/8 10 = FOSC/32 11 = FRC (clock derived from an RC oscillation) bit 5: Reserved bit 4-3: CHS<1:0>: Analog Channel Select bits 00 = channel 0, (GP0/AN0) 01 = channel 1, (GP1/AN1) 10 = channel 2, (GP2/AN2) 11 = channel 3, (GP4/AN3) 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) 0 = A/D conversion not in progress (this bit is automatically cleared by hardware when the A/D conversion is complete) bit 1: Reserved 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 1999 Microchip Technology Inc. DS30561B-page 45 PIC12C67X REGISTER 8-2: U-0 -- bit7 ADCON1 REGISTER (ADDRESS 9Fh) U-0 -- U-0 -- U-0 -- U-0 -- 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 7-2: Unimplemented: Read as '0' bit 1-0: PCFG<2:0>: A/D Port Configuration Control bits PCFG<2:0> GP4 GP2 GP1 GP0 VREF 000(1) 001 010 011 100 101 110 111 A A A A VDD A D D D D D D A A A D D D D VREF A VREF A VREF D D A A A A A A D GP1 VDD GP1 VDD GP1 VDD VDD A = Analog input D = Digital I/O Note 1: Value on reset. 2: Any instruction that reads a pin configured as an analog input will read a '0'. DS30561B-page 46 1999 Microchip Technology Inc. PIC12C67X The ADRES Register contains the result of the A/D conversion. When the A/D conversion is complete, the result is loaded into the ADRES register, the GO/DONE bit (ADCON0<2>) is cleared, and A/D interrupt flag bit ADIF (PIE1<6>) is set. The block diagrams of the A/D module are shown in Figure 8-1. 2. 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 TRIS bits selected as an input. To determine sample time, see Section 8.1. 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. OR 6. Configure the A/D module: * Configure analog pins / voltage reference / and digital I/O (ADCON1 and TRIS) * Select A/D input channel (ADCON0) * Select A/D conversion clock (ADCON0) * Turn on A/D module (ADCON0) FIGURE 8-1: Configure A/D interrupt (if desired): * Clear ADIF bit * Set ADIE bit * Set GIE 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 7. * Waiting for the A/D interrupt Read A/D Result Register (ADRES), clear bit ADIF if required. For the next conversion, go to step 1, step 2 or step 3 as required. The A/D conversion time per bit is defined as TAD. A minimum wait of 2TAD is required before next acquisition starts. A/D BLOCK DIAGRAM CHS<1:0> 11 GP4/AN3 VIN 10 (Input voltage) GP2/AN2 01 A/D Converter GP1/AN1/VREF 00 GP0/AN0 VDD VREF (Reference voltage) PCFG<2:0> 1999 Microchip Technology Inc. DS30561B-page 47 PIC12C67X 8.1 A/D Sampling Requirements Note 1: The reference voltage (VREF) has no effect on the equation, since it cancels itself out. 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 8-2. 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), see Figure 8-2. The maximum recommended impedance for analog sources is 10 k. 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 8-1 may be used. This equation assumes that 1/2 LSb error is used (512 steps for the A/D). The 1/2 LSb error is the maximum error allowed for the A/D to meet its specified resolution. EQUATION 8-1: A/D MINIMUM CHARGING TIME 2: The charge holding capacitor (CHOLD) is not discharged after each conversion. 3: The maximum recommended impedance for analog sources is 10 k. This is required to meet the pin leakage specification. 4: After a conversion has completed, a 2.0 TAD delay must complete before acquisition can begin again. During this time, the holding capacitor is not connected to the selected A/D input channel. EXAMPLE 8-1: CALCULATING THE MINIMUM REQUIRED SAMPLE TIME TACQ = Internal Amplifier Settling Time + Holding Capacitor Charging Time + VHOLD = (VREF - (VREF/512)) * (1 - e(-Tc/CHOLD(RIC + RSS + RS))) Temperature Coefficient or TACQ = 5 s + Tc + [(Temp - 25C)(0.05 s/C)] Tc = -(51.2 pF)(1 k + RSS + RS) ln(1/511) Example 8-1 shows the calculation of the minimum required acquisition time TACQ. This calculation is based on the following system assumptions. TC = -CHOLD (RIC + RSS + RS) ln(1/512) -51.2 pF (1 k + 7 k + 10 k) ln(0.0020) -51.2 pF (18 k) ln(0.0020) Rs = 10 k -0.921 s (-6.2146) 1/2 LSb error 5.724 s VDD = 5V Rss = 7 k TACQ = 5 s + 5.724 s + [(50C - 25C)(0.05 s/C)] Temp (system max.) = 50C 10.724 s + 1.25 s VHOLD = 0 @ t = 0 11.974 s FIGURE 8-2: ANALOG INPUT MODEL VDD Rs VA Sampling Switch VT = 0.6V RAx CPIN 5 pF VT = 0.6V RIC 1k SS Rss CHOLD = DAC capacitance = 51.2 pF I leakage 500 nA VSS Legend: CPIN = input capacitance VT = threshold voltage I leakage = leakage current at the pin due to various junctions RIC SS CHOLD DS30561B-page 48 = interconnect resistance = sampling switch = sample/hold capacitance (from DAC) 6V 5V VDD 4V 3V 2V 5 6 7 8 9 10 11 Sampling Switch ( k ) 1999 Microchip Technology Inc. PIC12C67X 8.2 Selecting the A/D Conversion Clock The A/D conversion time per bit is defined as TAD. The A/D conversion requires 9.5 TAD per 8-bit conversion. The source of the A/D conversion clock is software selected. The four possible options for TAD are: * * * * 2TOSC 8TOSC 32TOSC Internal ADC RC oscillator Configuring Analog Port Pins The ADCON1 and TRIS Registers control the operation of the A/D port pins. The port pins that are desired as analog inputs must have their corresponding TRIS bits set (input). If the TRIS 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 CHS<2:0> bits and the TRIS bits. For correct A/D conversions, the A/D conversion clock (TAD) must be selected to ensure a minimum TAD time of 1.6 s. If the minimum TAD time of 1.6 s can not be obtained, TAD should be 8 s for preferred operation. Table 8-1 shows the resultant TAD times derived from the device operating frequencies and the A/D clock source selected. TABLE 8-1: 8.3 Note 1: When reading the port register, all pins configured as analog input channel will read as cleared (a low level). Pins configured as digital inputs, will convert an analog input. Analog levels on a digitally configured input will not affect the conversion accuracy. 2: Analog levels on any pin that is defined as a digital input (including the AN<3:0> pins) may cause the input buffer to consume current that is out of the devices specification. TAD vs. DEVICE OPERATING FREQUENCIES Device Frequency AD Clock Source (TAD) Operation ADCS<1:0> 4 MHz 1.25 MHz 333.33 kHz 1.6 s 6 s 6.4 s 24 s(3) 2TOSC 00 8TOSC 01 500 2.0 s 32TOSC 10 8.0 s 25.6 s(3) 96 s(3) Internal ADC RC Oscillator(5) 11 2 - 6 s(1,4) 2 - 6 s(1,4) 2 - 6 s(1) Note 1: 2: 3: 4: 5: ns(2) The RC source has a typical TAD time of 4 s. These values violate the minimum required TAD time. For faster conversion times, the selection of another clock source is recommended. While in RC mode, with device frequency above 1 MHz, conversion accuracy is out of specification. For extended voltage devices (LC), please refer to Electrical Specifications section. 1999 Microchip Technology Inc. DS30561B-page 49 PIC12C67X 8.4 A/D Conversions Example 8-2 shows how to perform an A/D conversion. The GPIO pins are configured as analog inputs. The analog reference (VREF) is the device VDD. The A/D interrupt is enabled and the A/D conversion clock is FRC. The conversion is performed on the GP0 channel. Note: The GO/DONE bit should NOT be set in the same instruction that turns on the A/D. EXAMPLE 8-2: BSF CLRF BSF BCF MOVLW MOVWF BCF BSF BSF ; ; ; ; Clearing the GO/DONE bit during a conversion will abort the current conversion. The ADRES register will NOT be updated with the partially completed A/D conversion sample. That is, the ADRES register will continue to contain the value of the last completed conversion (or the last value written to the ADRES register). After the A/D conversion is aborted, a 2TAD wait is required before the next acquisition is started. After this 2TAD wait, an acquisition is automatically started on the selected channel. DOING AN A/D CONVERSION STATUS, ADCON1 PIE1, STATUS, 0xC1 ADCON0 PIR1, INTCON, INTCON, RP0 ADIE RP0 ADIF PEIE GIE ; ; ; ; ; ; ; ; ; Select Page 1 Configure A/D inputs Enable A/D interrupts Select Page 0 RC Clock, A/D is on, Channel 0 is selected Clear A/D interrupt flag bit 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. BSF : : ADCON0, GO DS30561B-page 50 ; Start A/D Conversion ; The ADIF bit will be set and the GO/DONE bit ; is cleared upon completion of the A/D Conversion. 1999 Microchip Technology Inc. PIC12C67X A/D Accuracy/Error The overall accuracy of the A/D is less than 1 LSb for VDD = 5V 10% and the analog VREF = VDD. This overall accuracy includes offset error, full scale error, and integral error. The A/D converter is monotonic over the full VDD range. The resolution and accuracy may be less when either the analog reference (VDD) is less than 5.0V or when the analog reference (VREF) is less than VDD. 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 8 s for preferred operation. This is because TAD, when derived from TOSC, is kept away from on-chip phase clock transitions. This reduces, to a large extent, the effects of digital switching noise. This is not possible with the RC derived clock. The loss of accuracy due to digital switching noise can be significant if many I/O pins are active. If the input voltage exceeds the rail values (VSS or VDD) by greater than 0.2V, then the accuracy of the conversion is out of specification. Note: For the PIC12C67X, care must be taken when using the GP4 pin in A/D conversions due to its proximity to the OSC1 pin. An external RC filter is sometimes added for antialiasing of the input signal. The R component should be selected to ensure that the total source impedance is kept under the 10 k recommended specification. Any external components connected (via hi-impedance) to an analog input pin (capacitor, zener diode, etc.) should have very little leakage current at the pin. 8.9 Transfer Function The ideal transfer function of the A/D converter is as follows: the first transition occurs when the analog input voltage (VAIN) is 1 LSb (or Analog VREF / 256) (Figure 8-3). FIGURE 8-3: A/D TRANSFER FUNCTION FFh FEh 04h 03h 02h 01h 00h 256 LSb (full scale) 8.6 For the A/D module to operate in SLEEP, the A/D clock source must be set to RC (ADCS<1:0> = 11). To perform an A/D conversion in SLEEP, the GO/DONE bit must be set, followed by the SLEEP instruction. Connection Considerations 255 LSb Note: 8.8 4 LSb Turning off the A/D places the A/D module in its lowest current consumption state. 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 ADRES register is not modified for a Reset. The ADRES register will contain unknown data after a Power-on Reset. 3 LSb 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. Effects of a Reset 2 LSb The A/D module can operate during SLEEP mode. This requires that the A/D clock source be set to RC (ADCS<1:0> = 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. 8.7 0.5 LSb 1 LSb A/D Operation During Sleep Digital code output 8.5 Analog input voltage 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. 1999 Microchip Technology Inc. DS30561B-page 51 PIC12C67X FIGURE 8-4: FLOWCHART OF A/D OPERATION ADON = 0 Yes ADON = 0? No Acquire Selected Channel Yes GO = 0? No Yes A/D Clock = RC? Start of A/D Conversion Delayed 1 Instruction Cycle SLEEP Yes Instruction? Finish Conversion GO = 0 ADIF = 1 No No Yes Device in SLEEP? Abort Conversion GO = 0 ADIF = 0 Wake-up Yes From Sleep? Finish Conversion GO = 0 ADIF = 1 Wait 2 TAD No No SLEEP Power-down A/D Finish Conversion GO = 0 ADIF = 1 Stay in Sleep Power-down A/D Wait 2 TAD Wait 2 TAD TABLE 8-2: SUMMARY OF A/D REGISTERS Address Name 0Bh/8Bh INTCON(1) Bit 7 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 GIE PEIE T0IE INTE GPIE T0IF INTF GPIF 0000 000x 0000 000u -- ADIF -- -- -- -- -- -- -0-- ---- -0-- ---- -- ADIE -- -- -- -- -- -- -0-- ---- -0-- ---- xxxx xxxx uuuu uuuu 0Ch 8Ch PIE1 1Eh ADRES A/D Result Register 1Fh ADCON0 ADCS1 ADCS0 reserved CHS1 9Fh ADCON1 85h GPIO TRIS Value on all other Resets Bit 5 PIR1 05h Value on Power-on Reset Bit 6 CHS0 GO/DONE reserved ADON 0000 0000 0000 0000 -- -- -- -- -- PCFG2 PCFG1 PCFG0 ---- -000 ---- -000 SCL(2) SDA(2) GP5 GP4 GP3 GP2 GP1 GP0 11xx xxxx 11uu uuuu TRIS0 --11 1111 --11 1111 -- -- TRIS5 TRIS4 TRIS3 TRIS2 TRIS1 Legend: x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are not used for A/D conversion. Note 1: These registers can be addressed from either bank. 2: The SCL (GP7) and SDA (GP6) bits are unimplemented on the PIC12C671/672 and read as '0'. DS30561B-page 52 1999 Microchip Technology Inc. PIC12C67X 9.0 SPECIAL FEATURES OF THE CPU What sets a microcontroller apart from other processors are special circuits to deal with the needs of realtime applications. The PIC12C67X 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 * Reset - Power-on Reset (POR) - Power-up Timer (PWRT) - Oscillator Start-up Timer (OST) * Interrupts * Watchdog Timer (WDT) * SLEEP * Code protection * ID locations * In-circuit serial programming CP1 CP0 CP1 SLEEP mode is designed to offer a very low current power-down mode. The user can wake-up from SLEEP through external reset, Watchdog Timer Wake-up, or through an interrupt. Several oscillator options are also made available to allow the part to fit the application. The INTRC/EXTRC oscillator option saves system cost, while the LP crystal option saves power. A set of configuration bits are used to select various options. 9.1 Configuration Bits The configuration bits can be programmed (read as '0') or left unprogrammed (read as '1') to select various device configurations. These bits are mapped in program memory location 2007h. The PIC12C67X has a Watchdog Timer, which can be shut off only through configuration bits. It runs off its own RC oscillator for added reliability. There are two timers that offer necessary delays on power-up. One is the Oscillator Start-up Timer (OST), intended to keep REGISTER 9-1: the chip in reset until the crystal oscillator is stable. The other is the Power-up Timer (PWRT), which provides a fixed delay of 72 ms (nominal) on power-up only, designed to keep the part in reset while the power supply stabilizes. With these two timers on-chip, most applications need no external reset circuitry. The user will note that address 2007h is beyond the user program memory space. In fact, it belongs to the special test/configuration memory space (2000h3FFFh), which can be accessed only during programming. CONFIGURATION WORD CP0 CP1 CP0 MCLRE CP1 bit13 CP0 PWRTE WDTE FOSC2 FOSC1 FOSC0 bit0 Register: Address CONFIG 2007h bit 13-8, CP<1:0>: Code Protection bit pairs(1) 6-5: 11 = Code protection off 10 = Locations 400h through 7FEh code protected (do not use for PIC12C671 and PIC12CE673) 01 = Locations 200h through 7FEh code protected 00 = All memory is code protected bit 7: MCLRE: Master Clear Reset Enable bit 1 = Master Clear Enabled 0 = Master Clear Disabled bit 4: PWRTE: Power-up Timer Enable bit 1 = PWRT disabled 0 = PWRT enabled bit 3: WDTE: Watchdog Timer Enable bit 1 = WDT enabled 0 = WDT disabled bit 2-0: FOSC<2:0>: Oscillator Selection bits 111 = EXTRC, Clockout on OSC2 110 = EXTRC, OSC2 is I/O 101 = INTRC, Clockout on OSC2 100 = INTRC, OSC2 is I/O 011 = Invalid Selection 010 = HS Oscillator 001 = XT Oscillator 000 = LP Oscillator Note 1: All of the CP<1:0> pairs have to be given the same value to enable the code protection scheme listed. 1999 Microchip Technology Inc. DS30561B-page 53 PIC12C67X 9.2 Oscillator Configurations 9.2.1 OSCILLATOR TYPES TABLE 9-1: The PIC12C67X can be operated in seven different oscillator modes. The user can program three configuration bits (FOSC<2:0>) to select one of these seven modes: * * * * * LP: HS: XT: INTRC*: EXTRC*: Low Power Crystal High Speed Crystal/Resonator Crystal/Resonator Internal 4 MHz Oscillator External Resistor/Capacitor *Can be configured to support CLKOUT 9.2.2 CRYSTAL OSCILLATOR / CERAMIC RESONATORS In XT, HS or LP modes, a crystal or ceramic resonator is connected to the GP5/OSC1/CLKIN and GP4/OSC2 pins to establish oscillation (Figure 9-1). The PIC12C67X 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. When in XT, HS or LP modes, the device can have an external clock source drive the GP5/OSC1/CLKIN pin (Figure 9-2). FIGURE 9-1: CRYSTAL OPERATION (OR CERAMIC RESONATOR) (XT, HS OR LP OSC CONFIGURATION) C1(1) OSC1 PIC12C67X SLEEP XTAL RS(2) RF(3) OSC2 To internal logic C2(1) Note 1: See Capacitor Selection tables for recommended values of C1 and C2. 2: A series resistor (RS) may be required for AT strip cut crystals. 3: RF varies with the oscillator mode selected (approx. value = 10 M). FIGURE 9-2: Osc Type CAPACITOR SELECTION FOR CERAMIC RESONATORS - PIC12C67X Resonator Freq Cap. Range C1 Cap. Range C2 XT 455 kHz 22-100 pF 22-100 pF 2.0 MHz 15-68 pF 15-68 pF 4.0 MHz 15-68 pF 15-68 pF HS 4.0 MHz 15-68 pF 15-68 pF 8.0 MHz 10-68 pF 10-68 pF 10.0 MHz 10-22 pF 10-22 pF 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. TABLE 9-2: CAPACITOR SELECTION FOR CRYSTAL OSCILLATOR - PIC12C67X Osc Type Resonator Freq Cap. Range C1 Cap. Range C2 LP 32 kHz(1) 100 kHz 200 kHz 100 kHz 200 kHz 455 kHz 1 MHz 2 MHz 4 MHz 4 MHz 8 MHz 10 MHz 15 pF 15-30 pF 15-30 pF 15-30 pF 15-30 pF 15-30 pF 15-30 pF 15-30 pF 15-47 pF 15-30 pF 15-30 pF 15-30 pF 15 pF 30-47 pF 15-82 pF 200-300 pF 100-200 pF 15-100 pF 15-30 pF 15-30 pF 15-47 pF 15-30 pF 15-30 pF 15-30 pF XT HS Note 1: For VDD > 4.5V, C1 = C2 30 pF is recommended. These values are for design guidance only. Rs may be required in HS mode, as well as XT mode, to avoid overdriving crystals with low drive level specification. Since each crystal has its own characteristics, the user should consult the crystal manufacturer for appropriate values of external components. EXTERNAL CLOCK INPUT OPERATION (XT, HS OR LP OSC CONFIGURATION) OSC1 Clock from ext. system PIC12C67X Open DS30561B-page 54 OSC2 1999 Microchip Technology Inc. PIC12C67X 9.2.3 EXTERNAL CRYSTAL OSCILLATOR CIRCUIT Either a pre-packaged oscillator or a simple oscillator circuit with TTL gates can be used as an external crystal oscillator circuit. Pre-packaged 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 parallel resonance or one with series resonance. Figure 9-3 shows implementation of a parallel resonant oscillator circuit. The circuit is designed to use the fundamental frequency of the crystal. The 74AS04 inverter performs the 180-degree phase shift that a parallel oscillator requires. The 4.7 k resistor provides the negative feedback for stability. The 10 k potentiometers bias the 74AS04 in the linear region. This circuit could be used for external oscillator designs. FIGURE 9-3: EXTERNAL PARALLEL RESONANT CRYSTAL OSCILLATOR CIRCUIT +5V To Other Devices 10k 74AS04 4.7k PIC12C67X 74AS04 CLKIN 10k XTAL 9.2.4 EXTERNAL RC OSCILLATOR For timing insensitive applications, the RC device option offers additional cost savings. The 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, the 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 the 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 9-5 shows how the R/C combination is connected to the PIC12C67X. For REXT values below 2.2 k, the oscillator operation may become unstable or stop completely. For very high REXT values (i.e., 1 M), the oscillator becomes sensitive to noise, humidity and leakage. Thus, we recommend keeping REXT between 3 k and 100 k. Although the oscillator will operate with no external capacitor (CEXT = 0 pF), we recommend using values above 20 pF for noise and stability reasons. With no or small external capacitance, the oscillation frequency can vary dramatically due to changes in external capacitances, such as PCB trace capacitance or package lead frame capacitance. 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). FIGURE 9-5: 10k EXTERNAL RC OSCILLATOR MODE VDD 20 pF 20 pF REXT Figure 9-4 shows a series resonant oscillator circuit. This circuit is also designed to use the fundamental frequency of the crystal. The inverter performs a 180degree phase shift in a series resonant oscillator circuit. The 330 resistors provide the negative feedback to bias the inverters in their linear region. FIGURE 9-4: Internal clock OSC1 N CEXT PIC12C67X VSS FOSC/4 OSC2/CLKOUT EXTERNAL SERIES RESONANT CRYSTAL OSCILLATOR CIRCUIT 330 330 74AS04 74AS04 To Other Devices 74AS04 PIC12C67X CLKIN 0.1 F XTAL 1999 Microchip Technology Inc. DS30561B-page 55 PIC12C67X 9.2.5 INTERNAL 4 MHz RC OSCILLATOR The internal RC oscillator provides a fixed 4 MHz (nominal) system clock at VDD = 5V and 25C. See Section 13.0 for information on variation over voltage and temperature. In addition, a calibration instruction is programmed into the last address of the program memory which contains the calibration value for the internal RC oscillator. This value is programmed as a RETLW XX instruction where XX is the calibration value. In order to retrieve the calibration value, issue a CALL YY instruction where YY is the last location in program memory (03FFh for the PIC12C671 and the PIC12CE673, 07FFh for the PIC12C672 and the PIC12CE674). Control will be returned to the user's program with the calibration value loaded into the W register. The program should then perform a MOVWF OSCCAL instruction to load the value into the internal RC oscillator trim register. OSCCAL, when written to with the calibration value, will "trim" the internal oscillator to remove process variation from the oscillator frequency. Bits <7:4>, CAL<3:0> are used for fine calibration, while bit 3, CALFST, and bit 2, CALSLW, are used for more coarse adjustment. Adjusting CAL<3:0> from 0000 to 1111 yields a higher clock speed. Set CALFST = 1 for greater increase in frequency or set CALSLW = 1 for greater decrease in frequency. Note that bits 1 and 0 of OSCCAL are unimplemented and should be written as 0 when modifying OSCCAL for compatibility with future devices. Note: 9.2.6 Please note that erasing the device will also erase the pre-programmed internal calibration value for the internal oscillator. The calibration value must be saved prior to erasing the part. 9.3 Reset The PIC12C67X differentiates between various kinds of reset: * * * * Power-on Reset (POR) MCLR Reset during normal operation MCLR Reset during SLEEP WDT Reset (normal operation) 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 reset to a "reset state" on Power-on Reset (POR), MCLR Reset, WDT Reset, and MCLR Reset during SLEEP. They are not affected by a WDT Wake-up, which is viewed as the resumption of normal operation. The TO and PD bits are set or cleared differently in different reset situations, as indicated in Table 9-5. These bits are used in software to determine the nature of the reset. See Table 9-6 for a full description of reset states of all registers. A simplified block diagram of the on-chip reset circuit is shown in Figure 9-6. The PIC12C67X has a MCLR noise filter in the MCLR reset path. The filter will detect and ignore small pulses. It should be noted that a WDT Reset does not drive MCLR pin low. When MCLR is asserted, the state of the OSC1/CLKIN and CLKOUT/OSC2 pins are as follows: TABLE 9-3: Oscillator Mode DS30561B-page 56 OSC1/CLKIN Pin OSC2/CLKout Pin EXTRC, CLKOUT on OSC2 OSC1 pin is tristated and driven by external circuit OSC2 pin is driven low EXTRC, OSC2 is I/O OSC1 pin is tristated and driven by external circuit OSC2 pin is tristate input INTRC, CLKOUT on OSC2 OSC1 pin is tristate input OSC2 pin is driven low INTRC, OSC2 is I/O OSC1 pin is tristate input OSC2 pin is tristate input CLKOUT The PIC12C67X can be configured to provide a clock out signal (CLKOUT) on pin 3 when the configuration word address (2007h) is programmed with FOSC2, FOSC1, and FOSC0, equal to 101 for INTRC or 111 for EXTRC. The oscillator frequency, divided by 4, can be used for test purposes or to synchronize other logic. CLKIN/CLKOUT PIN STATES WHEN MCLR ASSERTED 1999 Microchip Technology Inc. PIC12C67X FIGURE 9-6: SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT Weak Pull-up GP3/MCLR/VPP Pin MCLRE INTERNAL MCLR WDT SLEEP Module WDT Time-out VDD rise detect Power-on Reset VDD S OST/PWRT OST Chip_Reset 10-bit Ripple-counter OSC1/ CLKIN Pin On-chip(1) RC OSC R Q PWRT 10-bit Ripple-counter Enable PWRT See Table 9-4 for time-out situations. Enable OST Note 1: This is a separate oscillator from the RC oscillator of the CLKIN pin. 1999 Microchip Technology Inc. DS30561B-page 57 PIC12C67X 9.4 Power-on Reset (POR), Power-up Timer (PWRT) and Oscillator Start-up Timer (OST) 9.4.1 POWER-ON RESET (POR) The on-chip POR circuit holds the chip in reset until VDD has reached a high enough level for proper operation. To take advantage of the POR, just tie the MCLR pin through a resistor to VDD. This will eliminate external RC components usually needed to create a Poweron Reset. A maximum rise time for VDD is specified. See Electrical Specifications for details. When the device starts normal operation (exits the reset condition), device operating parameters (voltage, frequency, temperature, ...) must be met to ensure operation. If these conditions are not met, the device must be held in reset until the operating conditions are met. For additional information, refer to Application Note AN607, "Power-up Trouble Shooting." 9.4.2 POWER-UP TIMER (PWRT) The Power-up Timer provides a fixed 72 ms nominal time-out on power-up only, from the POR. The Powerup Timer operates on an internal RC oscillator. The chip is kept in reset as long as the PWRT is active. The PWRT's time delay allows VDD to rise to an acceptable level. A configuration bit is provided to enable/disable the PWRT. The power-up time delay will vary from chip to chip due to VDD, temperature and process variation. See Table 11-4. TABLE 9-4: 9.4.3 OSCILLATOR START-UP TIMER (OST) The Oscillator Start-up Timer (OST) provides 1024 oscillator cycle (from OSC1 input) delay after the PWRT delay is over. This ensures that the crystal oscillator or resonator has started and stabilized. The OST time-out is invoked only for XT, LP and HS modes and only on Power-on Reset or wake-up from SLEEP. 9.4.4 TIME-OUT SEQUENCE On power-up, the Time-out Sequence is as follows: first, PWRT time-out is invoked after the POR time delay has expired; then, OST is activated. The total time-out will vary, based on oscillator configuration and the status of the PWRT. For example, in RC mode with the PWRT disabled, there will be no time-out at all. Figure 9-7, Figure 9-8, and Figure 9-9 depict time-out sequences on power-up. Since the time-outs occur from the POR pulse, if MCLR is kept low long enough, the time-outs will expire. Then bringing MCLR high will begin execution immediately (Figure 9-9). This is useful for testing purposes or to synchronize more than one PIC12C67X device operating in parallel. 9.4.5 POWER CONTROL (PCON)/STATUS REGISTER The Power Control/Status Register, PCON (address 8Eh), has one bit. See Register 4-6 for register. Bit1 is POR (Power-on Reset). It is cleared on a Poweron Reset and is unaffected otherwise. The user sets this bit following a Power-on Reset. On subsequent resets, if POR is `0', it will indicate that a Power-on Reset must have occurred. TIME-OUT IN VARIOUS SITUATIONS Oscillator Configuration XT, HS, LP INTRC, EXTRC TABLE 9-5: Power-up PWRTE = 0 72 ms + 1024TOSC 72 ms PWRTE = 1 1024TOSC -- Wake-up from SLEEP 1024TOSC -- STATUS/PCON BITS AND THEIR SIGNIFICANCE POR TO PD 0 0 0 1 1 1 1 1 0 x 0 0 u 1 1 x 0 u 0 u 0 Power-on Reset Illegal, TO is set on POR Illegal, PD is set on POR WDT Reset WDT Wake-up MCLR Reset during normal operation MCLR Reset during SLEEP or interrupt wake-up from SLEEP Legend: u = unchanged, x = unknown. DS30561B-page 58 1999 Microchip Technology Inc. PIC12C67X TABLE 9-6: RESET CONDITION FOR SPECIAL REGISTERS Program Counter STATUS Register PCON Register Power-on Reset 000h 0001 1xxx ---- --0- MCLR Reset during normal operation 000h 000u uuuu ---- --u- MCLR Reset during SLEEP 000h 0001 0uuu ---- --u- WDT Reset during normal operation 000h 0000 uuuu ---- --u- PC + 1 uuu0 0uuu ---- --u- PC + 1(1) uuu1 0uuu ---- --u- Condition WDT Wake-up from SLEEP Interrupt wake-up from SLEEP Legend: u = unchanged, x = unknown, - = unimplemented bit read as '0'. Note 1: When the wake-up is due to an interrupt and the GIE bit is set, the PC is loaded with the interrupt vector (0004h). TABLE 9-7: Register INITIALIZATION CON\DITIONS FOR ALL REGISTERS Power-on Reset MCLR Resets WDT Reset Wake-up via WDT or Interrupt W xxxx xxxx uuuu uuuu uuuu uuuu INDF 0000 0000 0000 0000 0000 0000 TMR0 xxxx xxxx uuuu uuuu uuuu uuuu PCL 0000 0000 0000 0000 PC + 1(2) STATUS 0001 1xxx 000q quuu(3) uuuq quuu(3) FSR xxxx xxxx uuuu uuuu uuuu uuuu GPIO PIC12CE67X 11xx xxxx 11uu uuuu 11uu uuuu GPIO PIC12C67X --xx xxxx --uu uuuu --uu uuuu PCLATH ---0 0000 ---0 0000 ---u uuuu INTCON 0000 000x 0000 000u uuuu uqqq(1) PIR1 -0-- ---- -0-- ---- -q-- ----(4) ADCON0 0000 0000 0000 0000 uuuu uquu(5) OPTION 1111 1111 1111 1111 uuuu uuuu TRIS --11 1111 --11 1111 --uu uuuu PIE1 -0-- ---- -0-- ---- -u-- ---- PCON ---- --0- ---- --u- ---- --u- OSCCAL 0111 00-- uuuu uu-- uuuu uu-- ADCON1 ---- -000 ---- -000 ---- -uuu Legend: Note 1: 2: 3: 4: 5: u = unchanged, x = unknown, - = unimplemented bit, read as '0', q = value depends on condition. One or more bits in INTCON and PIR1 will be affected (to cause wake-up). When the wake-up is due to an interrupt and the GIE bit is set, the PC is loaded with the interrupt vector (0004h). See Table 9-5 for reset value for specific condition. If wake-up was due to A/D completing then bit 6 = 1, all other interrupts generating a wake-up will cause bit 6 = u. If wake-up was due to A/D completing then bit 3 = 0, all other interrupts generating a wake-up will cause bit 3 = u. 1999 Microchip Technology Inc. DS30561B-page 59 PIC12C67X FIGURE 9-7: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1 VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2 FIGURE 9-8: VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD) FIGURE 9-9: VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET DS30561B-page 60 1999 Microchip Technology Inc. PIC12C67X FIGURE 9-10: EXTERNAL POWER-ON RESET CIRCUIT (FOR SLOW VDD POWER-UP) FIGURE 9-11: EXTERNAL BROWN-OUT PROTECTION CIRCUIT 1 VDD D VDD 33k VDD 10k R R1 4.3k MCLR C MCLR PIC12C67X PIC12C67X Note 1: External Power-on Reset circuit is required only if VDD power-up slope is too slow. The diode D helps discharge the capacitor quickly when VDD powers down. 2: R < 40 k is recommended to make sure that voltage drop across R does not violate the device's electrical specification. 3: R1 = 100 to 1 k will limit any current flowing into MCLR from external capacitor C, in the event of MCLR/VPP pin breakdown due to Electrostatic Discharge (ESD) or Electrical Overstress (EOS). Note 1: This circuit will activate reset when VDD goes below (Vz + 0.7V), where Vz = Zener voltage. 2: Resistors should be adjusted for the characteristics of the transistor. FIGURE 9-12: EXTERNAL BROWN-OUT PROTECTION CIRCUIT 2 VDD VDD R1 Q1 MCLR R2 4.3k PIC12C67X Note 1: This brown-out circuit is less expensive, albeit less accurate. Transistor Q1 turns off when VDD is below a certain level such that: R1 = 0.7V VDD * R1 + R2 2: Resistors should be adjusted for the characteristics of the transistor. 1999 Microchip Technology Inc. DS30561B-page 61 PIC12C67X 9.5 Interrupts The "return-from-interrupt" instruction, RETFIE, exits the interrupt routine, as well as sets the GIE bit, which re-enables interrupts. There are four sources of interrupt: Interrupt Sources TMR0 Overflow Interrupt External Interrupt GP2/INT pin GPIO Port Change Interrupts (pins GP0, GP1, GP3) A/D Interrupt The Interrupt Control Register (INTCON) records individual interrupt requests in flag bits. It also has individual and global interrupt enable bits. Note: Individual interrupt flag bits are set, regardless of the status of their corresponding mask bit or the GIE bit. A global interrupt enable bit, GIE (INTCON<7>), enables (if set) all un-masked interrupts or disables (if cleared) all interrupts. When bit GIE is enabled and an interrupt's flag bit and mask bit are set, the interrupt will vector immediately. Individual interrupts can be disabled through their corresponding enable bits in various registers. Individual interrupt flag bits are set, regardless of the status of their corresponding mask bit or the GIE bit. The GIE bit is cleared on reset. The GP2/INT, GPIO port change interrupt and the TMR0 overflow interrupt flags are contained in the INTCON register. The peripheral interrupt flag ADIF, is contained in the Special Function Register PIR1. The corresponding interrupt enable bit is contained in Special Function Register PIE1, and the peripheral interrupt enable bit is contained in Special Function Register INTCON. When an interrupt is responded to, the GIE bit is cleared to disable any further interrupt, the return address is pushed onto the stack and the PC is loaded with 0004h. Once in the interrupt service routine, the source(s) of the interrupt can be determined by polling the interrupt flag bits. The interrupt flag bit(s) must be cleared in software before re-enabling interrupts to avoid repeated interrupts. For external interrupt events, such as GPIO change interrupt, the interrupt latency will be three or four instruction cycles. The exact latency depends on when the interrupt event occurs (Figure 9-14). The latency is the same for one or two cycle instructions. Individual interrupt flag bits are set, regardless of the status of their corresponding mask bit or the GIE bit. FIGURE 9-13: INTERRUPT LOGIC T0IF T0IE Wake-up (If in SLEEP mode) INTF INTE GPIF GPIE ADIF ADIE Interrupt to CPU PEIE GIE DS30561B-page 62 1999 Microchip Technology Inc. PIC12C67X FIGURE 9-14: INT PIN INTERRUPT TIMING Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 CLKOUT 3 4 INT pin INTF flag (INTCON<1>) 1 1 Interrupt Latency 2 5 GIE bit (INTCON<7>) INSTRUCTION FLOW PC PC Instruction fetched Inst (PC) Instruction executed Inst (PC-1) PC+1 Inst (PC+1) Inst (PC) 0004h PC+1 -- Dummy Cycle 0005h Inst (0004h) Inst (0005h) Dummy Cycle Inst (0004h) Note 1: INTF flag is sampled here (every Q1). 2: Interrupt latency = 3-4 TCY where TCY = instruction cycle time. Latency is the same whether Inst (PC) is a single cycle or a 2-cycle instruction. 3: CLKOUT is available only in INTRC and EXTRC oscillator modes. 4: For minimum width of INT pulse, refer to AC specs. 5: INTF is enabled to be set anytime during the Q4-Q1 cycles. 1999 Microchip Technology Inc. DS30561B-page 63 PIC12C67X 9.5.1 9.6 TMR0 INTERRUPT An overflow (FFh 00h) in the TMR0 register will set flag bit T0IF (INTCON<2>). The interrupt can be enabled/disabled by setting/clearing enable bit T0IE (INTCON<5>) (Section 7.0). The flag bit T0IF (INTCON<2>) will be set, regardless of the state of the enable bits. If used, this flag must be cleared in software. 9.5.2 INT INTERRUPT External interrupt on GP2/INT pin is edge triggered; either rising if bit INTEDG (OPTION<6>) is set, or falling, if the INTEDG bit is clear. When a valid edge appears on the GP2/INT pin, flag bit INTF (INTCON<1>) is set. This interrupt can be disabled by clearing enable bit INTE (INTCON<4>). Flag bit INTF must be cleared in software in the interrupt service routine before re-enabling this interrupt. The INT interrupt can wake-up the processor from SLEEP, if bit INTE was set prior to going into SLEEP. The status of global interrupt enable bit GIE decides whether or not the processor branches to the interrupt vector following wake-up. See Section 9.8 for details on SLEEP mode. 9.5.3 During an interrupt, only the return PC value is saved on the stack. Typically, users may wish to save key registers during an interrupt (i.e., W register and STATUS register). This will have to be implemented in software. Example 9-1 shows the storing and restoring of the STATUS and W registers. The register, W_TEMP, must be defined in both banks and must be defined at the same offset from the bank base address (i.e., if W_TEMP is defined at 0x20 in bank 0, it must also be defined at 0xA0 in bank 1). Example 9-2 shows the saving and restoring of STATUS and W using RAM locations 0x70 - 0x7F. W_TEMP is defined at 0x70 and STATUS_TEMP is defined at 0x71. The example: a) b) c) d) e) f) GPIO INTCON CHANGE Context Saving During Interrupts Stores the W register. Stores the STATUS register in bank 0. Executes the ISR code. Restores the STATUS register (and bank select bit). Restores the W register. Returns from interrupt. An input change on GP3, GP1 or GP0 sets flag bit GPIF (INTCON<0>). The interrupt can be enabled/disabled by setting/clearing enable bit GPIE (INTCON<3>) (Section 5.1) . This flag bit GPIF (INTCON<0>) will be set, regardless of the state of the enable bits. If used, this flag must be cleared in software. EXAMPLE 9-1: SAVING STATUS AND W REGISTERS USING GENERAL PURPOSE RAM (0x20 - 0x6F) MOVWF SWAPF BCF MOVWF : :(ISR) : SWAPF W_TEMP STATUS,W STATUS,RP0 STATUS_TEMP ;Copy W to TEMP ;Swap status to ;Change to bank ;Save status to STATUS_TEMP,W MOVWF SWAPF SWAPF RETFIE STATUS W_TEMP,F W_TEMP,W ;Swap STATUS_TEMP register into W ;(sets bank to original state) ;Move W into STATUS register ;Swap W_TEMP ;Swap W_TEMP into W ;Return from interrupt EXAMPLE 9-2: MOVWF MOVF MOVWF : :(ISR) : MOVF MOVWF SWAPF SWAPF RETFIE DS30561B-page 64 register, could be bank one or zero be saved into W zero, regardless of current bank bank zero STATUS_TEMP register SAVING STATUS AND W REGISTERS USING SHARED RAM (0x70 - 0x7F) W_TEMP STATUS,W STATUS_TEMP ;Copy W to TEMP register (bank independent) ;Move STATUS register into W ;Save contents of STATUS register STATUS_TEMP,W STATUS W_TEMP,F W_TEMP,W ;Retrieve copy of STATUS register ;Restore pre-isr STATUS register contents ; ;Restore pre-isr W register contents ;Return from interrupt 1999 Microchip Technology Inc. PIC12C67X 9.7 Watchdog Timer (WDT) The Watchdog Timer is a free running, on-chip RC oscillator, which 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 of the device has been stopped, for example, by execution of a SLEEP instruction. During normal operation, a WDT time-out generates a device RESET (Watchdog Timer Reset). If the device is in SLEEP mode, a WDT time-out causes the device to wake-up and continue with normal operation (Watchdog Timer Wake-up). The WDT can be permanently disabled by clearing configuration bit WDTE (Section 9.1). 9.7.1 The CLRWDT and SLEEP instructions clear the WDT and the postscaler, if assigned to the WDT, and prevent it from timing out early and generating a premature device RESET condition. The TO bit in the STATUS register will be cleared upon a Watchdog Timer time-out. 9.7.2 WDT PROGRAMMING CONSIDERATIONS It should also be taken into account that under worst case conditions (VDD = Min., Temperature = Max., and max. WDT prescaler), it may take several seconds before a WDT time-out occurs. Note: WDT PERIOD The WDT has a nominal time-out period of 18 ms (with no prescaler). 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, a prescaler with a division ratio of up to 1:128 can be assigned to the WDT under software control by writing to the OPTION register. Thus, time-out periods up to 2.3 seconds can be realized. When the prescaler is assigned to the WDT, always execute a CLRWDT instruction before changing the prescale value, otherwise a WDT reset may occur. See Example 7-1 and Example 7-2 for changing prescaler between WDT and Timer0. FIGURE 9-15: WATCHDOG TIMER BLOCK DIAGRAM From TMR0 Clock Source (Figure 7-5) 0 1 WDT Timer Postscaler M U X 8 8 - to - 1 MUX PS<2:0> PSA WDT Enable Bit To TMR0 (Figure 7-5) 0 1 MUX WDT Time-out Note: PSA and PS<2:0> are bits in the OPTION register. TABLE 9-8: PSA SUMMARY OF WATCHDOG TIMER REGISTERS Address Name 2007h Config. bits(1) 81h OPTION Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 MCLRE CP1 CP0 PWRTE WDTE FOSC2 FOSC1 FOSC0 GPPU INTEDG T0CS T0SE PSA PS2 PS1 PS0 Legend: Shaded cells are not used by the Watchdog Timer. Note 1: See Register 9-1 for operation of these bits. Not all CP0 and CP1 bits are shown. 1999 Microchip Technology Inc. DS30561B-page 65 PIC12C67X 9.8 Power-down Mode (SLEEP) Power-down mode is entered by executing a SLEEP instruction. If enabled, the Watchdog Timer will be cleared but keeps running, the PD bit (STATUS<3>) is cleared, the TO (STATUS<4>) bit is set, and the oscillator driver is turned off. The I/O ports maintain the status they had, before the SLEEP instruction was executed (driving high, low or hi-impedance). For lowest current consumption in this mode, place all I/O pins at either VDD or VSS, ensure no external circuitry is drawing current from the I/O pin, power-down the A/D, and disable external clocks. Pull all I/O pins that are hi-impedance inputs, high or low externally, to avoid switching currents caused by floating inputs. The T0CKI input, if enabled, should also be at VDD or VSS for lowest current consumption. The contribution from on-chip pull-ups on GPIO should be considered. The MCLR pin, if enabled, must be at a logic high level (VIHMC). 9.8.1 WAKE-UP FROM SLEEP The device can wake-up from SLEEP through one of the following events: 1. 2. 3. External reset input on MCLR pin. Watchdog Timer Wake-up (if WDT was enabled). GP2/INT interrupt, interrupt GPIO port change or some Peripheral Interrupts. External MCLR Reset will cause a device reset. All other events are considered a continuation of program execution and cause a "wake-up". The TO and PD bits in the STATUS 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 a WDT time-out occurred (and caused wake-up). The following peripheral interrupt can wake the device from SLEEP: 1. Other peripherals can not generate interrupts since during SLEEP, no on-chip Q clocks are present. 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 GIE bit. If the GIE bit is clear (disabled), the device continues execution at the instruction after the SLEEP instruction. If the GIE bit is set (enabled), the device executes the instruction after the SLEEP instruction and then branches to the interrupt address (0004h). In cases where the execution of the instruction following SLEEP is not desirable, the user should have a NOP after the SLEEP instruction. 9.8.2 WAKE-UP USING INTERRUPTS When global interrupts are disabled (GIE cleared) and any interrupt source has both its interrupt enable bit and interrupt flag bit set, one of the following will occur: * If the interrupt occurs before the the execution of a SLEEP instruction, the SLEEP instruction will complete as a NOP. Therefore, the WDT and WDT postscaler will not be cleared, the TO bit will not be set and PD bits will not be cleared. * If the interrupt occurs during or after the execution of a SLEEP instruction, the device will immediately wake-up from sleep . The SLEEP instruction will be completely executed before the wake-up. Therefore, the WDT and WDT postscaler will be cleared, the TO bit will be set and the PD bit will be cleared. Even if the flag bits were checked before executing a SLEEP instruction, it may be possible for flag bits to become set before the SLEEP instruction completes. To determine whether a SLEEP instruction executed, test the PD bit. If the PD bit is set, the SLEEP instruction was executed as a NOP. To ensure that the WDT is cleared, a CLRWDT instruction should be executed before a SLEEP instruction. A/D conversion (when A/D clock source is RC). DS30561B-page 66 1999 Microchip Technology Inc. PIC12C67X FIGURE 9-16: WAKE-UP FROM SLEEP THROUGH INTERRUPT Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 TOST(2) CLKOUT(4) GPIO pin GPIF flag (INTCON<0>) Interrupt Latency (Note 3) GIE bit (INTCON<7>) Processor in SLEEP INSTRUCTION FLOW PC PC Instruction fetched Inst(PC) = SLEEP Instruction executed Inst(PC - 1) PC+1 PC+2 PC+2 PC + 2 Inst(PC + 1) Inst(PC + 2) SLEEP Inst(PC + 1) Dummy cycle 0004h 0005h Inst(0004h) Inst(0005h) Dummy cycle Inst(0004h) Note 1: XT, HS or LP oscillator mode assumed. 2: TOST = 1024TOSC (drawing not to scale) This delay will not be there for INTRC and EXTRC osc mode. 3: GIE = '1' assumed. In this case after wake- up, the processor jumps to the interrupt routine. If GIE = '0', execution will continue in-line. 4: CLKOUT is not available in XT, HS or LP osc modes, but shown here for timing reference. 9.9 Program Verification/Code Protection If the code protection bit(s) have not been programmed, the on-chip program memory can be read out for verification purposes. Note: 9.10 Microchip does not recommend code protecting windowed devices. ID Locations Four memory locations (2000h - 2003h) are designated as ID locations, where the user can store checksum or other code-identification numbers. These locations are not accessible during normal execution, but are readable and writable during program/verify. It is recommended that only the 4 least significant bits of the ID location are used. 9.11 In-Circuit Serial Programming PIC12C67X microcontrollers can be serially programmed while in the end application circuit. This is simply done with two lines for clock and data, and three other lines for power, ground and the programming voltage. This allows customers to manufacture boards with unprogrammed devices, and then program the microcontroller just before shipping the product. This also allows the most recent firmware or a custom firmware to be programmed. The device is placed into a program/verify mode by holding the GP1 and GP0 pins low, while raising the MCLR (VPP) pin from VIL to VIHH (see programming specification). GP1 (clock) becomes the programming clock and GP0 (data) becomes the programming data. Both GP0 and GP1 are Schmitt Trigger inputs in this mode. 1999 Microchip Technology Inc. After reset, and if the device is placed into programming/verify mode, the program counter (PC) is at location 00h. A 6-bit command is then supplied to the device. Depending on the command, 14-bits of program data are then supplied to or from the device, depending if the command was a load or a read. For complete details of serial programming, please refer to the PIC12C67X Programming Specifications. FIGURE 9-17: TYPICAL IN-CIRCUIT SERIAL PROGRAMMING CONNECTION External Connector Signals To Normal Connections PIC12C67X +5V VDD 0V VSS VPP MCLR/VPP CLK GP1 Data I/O GP0 VDD To Normal Connections DS30561B-page 67 PIC12C67X NOTES: DS30561B-page 68 1999 Microchip Technology Inc. PIC12C67X 10.0 INSTRUCTION SET SUMMARY Each PIC12C67X instruction is a 14-bit word divided into an OPCODE which specifies the instruction type and one or more operands which further specify the operation of the instruction. The PIC12C67X instruction set summary in Table 10-2 lists byte-oriented, bitoriented, and literal and control operations. Table 101 shows the opcode field descriptions. For byte-oriented instructions, 'f' represents a file register designator and 'd' represents a destination designator. The file register designator specifies which file register is to be used by the instruction. The destination designator specifies where the result of the operation is to be placed. If 'd' is zero, the result is placed in the W register. If 'd' is one, the result is placed in the file register specified in the instruction. For bit-oriented instructions, 'b' represents a bit field designator which selects the number of the bit affected by the operation, while 'f' represents the number of the file in which the bit is located. The instruction set is highly orthogonal and is grouped into three basic categories: * Byte-oriented operations * Bit-oriented operations * Literal and control operations All instructions are executed within one single instruction cycle, unless a conditional test is true or the program counter is changed as a result of an instruction. 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 4 MHz, the normal instruction execution time is 1 s. If a conditional test is true or the program counter is changed as a result of an instruction, the instruction execution time is 2 s. Table 10-2 lists the instructions recognized by the MPASM assembler. Figure 10-1 shows the three general formats that the instructions can have. Note: To maintain upward compatibility with future PIC12C67X products, do not use the OPTION and TRIS instructions. For literal and control operations, 'k' represents an eight or eleven bit constant or literal value. TABLE 10-1: OPCODE FIELD DESCRIPTIONS All examples use the following format to represent a hexadecimal number: 0xhh Field Description f Register file address (0x00 to 0x7F) W Working register (accumulator) b Bit address within an 8-bit file register k Literal field, constant data or label x Don't care location (= 0 or 1) The assembler will generate code with x = 0. It is the recommended form of use for compatibility with all Microchip software tools. d Destination select; d = 0: store result in W, d = 1: store result in file register f. Default is d = 1 label Label name TOS PC Top of Stack where h signifies a hexadecimal digit. FIGURE 10-1: GENERAL FORMAT FOR INSTRUCTIONS Byte-oriented file register operations 13 8 7 6 OPCODE d f (FILE #) d = 0 for destination W d = 1 for destination f f = 7-bit file register address Bit-oriented file register operations 13 10 9 7 6 OPCODE b (BIT #) f (FILE #) Program Counter Global Interrupt Enable bit WDT Watchdog Timer/Counter TO PD Time-out bit Power-down bit dest Destination either the W register or the specified register file location [ ] Options ( ) <> Contents 0 b = 3-bit bit address f = 7-bit file register address PCLATH Program Counter High Latch GIE 0 Literal and control operations General 13 8 7 OPCODE 0 k (literal) k = 8-bit immediate value CALL and GOTO instructions only 13 11 10 0 Assigned to OPCODE k (literal) Register bit field k = 11-bit immediate value In the set of italics User defined term (font is courier) 1999 Microchip Technology Inc. DS30561B-page 69 PIC12C67X 10.1 Special Function Registers as Source/Destination The PIC12C67X'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: 10.1.1 STATUS AS DESTINATION If an instruction writes to STATUS, the Z, C and DC bits may be set or cleared as a result of the instruction and overwrite the original data bits written. For example, executing CLRF STATUS will clear register STATUS, and then set the Z bit leaving 0000 0100b in the register. 10.1.3 Read, write or read-modify-write on PCL may have the following results: Read PC: 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. 10.1.4 10.1.2 PCL AS SOURCE OR DESTINATION BIT MANIPULATION TRIS AS DESTINATION Bit 3 of the TRIS register always reads as a '1' since GP3 is an input only pin. This fact can affect some readmodify-write operations on the TRIS register. DS30561B-page 70 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). The user should keep this in mind when operating on special function registers, such as ports. 1999 Microchip Technology Inc. PIC12C67X TABLE 10-2: Mnemonic, Operands INSTRUCTION SET SUMMARY Description Cycles 14-Bit Opcode MSb LSb Status Affected Notes BYTE-ORIENTED FILE REGISTER OPERATIONS ADDWF ANDWF CLRF CLRW COMF DECF DECFSZ INCF INCFSZ IORWF MOVF MOVWF NOP RLF RRF SUBWF SWAPF XORWF f, d f, d f f, d f, d f, d f, d f, d f, d f, d f f, d f, d f, d f, d f, d Add W and f AND W with f Clear f Clear W Complement f Decrement f Decrement f, Skip if 0 Increment f Increment f, Skip if 0 Inclusive OR W with f Move f Move W to f No Operation Rotate Left f through Carry Rotate Right f through Carry Subtract W from f Swap nibbles in f Exclusive OR W with f 1 1 1 1 1 1 1(2) 1 1(2) 1 1 1 1 1 1 1 1 1 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0111 0101 0001 0001 1001 0011 1011 1010 1111 0100 1000 0000 0000 1101 1100 0010 1110 0110 dfff dfff lfff 0000 dfff dfff dfff dfff dfff dfff dfff lfff 0xx0 dfff dfff dfff dfff dfff ffff ffff ffff 0011 ffff ffff ffff ffff ffff ffff ffff ffff 0000 ffff ffff ffff ffff ffff 1 1 1 (2) 1 (2) 01 01 01 01 00bb 01bb 10bb 11bb bfff bfff bfff bfff ffff ffff ffff ffff 1 1 2 1 2 1 1 2 2 2 1 1 1 11 11 10 00 10 11 11 00 11 00 00 11 11 111x 1001 0kkk 0000 1kkk 1000 00xx 0000 01xx 0000 0000 110x 1010 kkkk kkkk kkkk 0110 kkkk kkkk kkkk 0000 kkkk 0000 0110 kkkk kkkk kkkk kkkk kkkk 0100 kkkk kkkk kkkk 1001 kkkk 1000 0011 kkkk kkkk C,DC,Z Z Z Z Z Z Z Z Z C C C,DC,Z Z 1,2 1,2 2 1,2 1,2 1,2,3 1,2 1,2,3 1,2 1,2 1,2 1,2 1,2 1,2 1,2 BIT-ORIENTED FILE REGISTER OPERATIONS BCF BSF BTFSC BTFSS f, b f, b f, b f, b Bit Clear f Bit Set f Bit Test f, Skip if Clear Bit Test f, Skip if Set 1,2 1,2 3 3 LITERAL AND CONTROL OPERATIONS ADDLW ANDLW CALL CLRWDT GOTO IORLW MOVLW RETFIE RETLW RETURN SLEEP SUBLW XORLW k k k k k k k k k Add literal and W AND literal with W Call subroutine Clear Watchdog Timer Go to address Inclusive OR literal with W Move literal to W Return from interrupt Return with literal in W Return from Subroutine Go into standby mode Subtract W from literal Exclusive OR literal with W C,DC,Z Z TO,PD Z TO,PD C,DC,Z Z Note 1: When an I/O register is modified as a function of itself ( i.e., MOVF PORTB, 1), the value used will be that value present on the pins themselves. For example, if the data latch is '1' for a pin configured as input and is driven low by an external device, the data will be written back with a '0'. 2: If this instruction is executed on the TMR0 register (and, where applicable, d = 1), the prescaler will be cleared if assigned to the Timer0 Module. 3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second cycle is executed as a NOP. 1999 Microchip Technology Inc. DS30561B-page 71 PIC12C67X 10.2 Instruction Descriptions ADDLW Add Literal and W Syntax: [ label ] ADDLW Operands: 0 k 255 Operation: (W) + k (W) Status Affected: C, DC, Z Encoding: 11 k 111x kkkk kkkk ANDLW And Literal with W Syntax: [ label ] ANDLW Operands: 0 k 255 Operation: (W) .AND. (k) (W) Status Affected: Z Encoding: 11 k 1001 kkkk kkkk Description: The contents of the W register are added to the eight bit literal 'k' and the result is placed in the W register. Description: The contents of W register are AND'ed with the eight bit literal 'k'. The result is placed in the W register. Words: 1 Words: 1 Cycles: 1 Cycles: 1 Example ADDLW 0x15 Example Before Instruction W = = ADDWF Add W and f Syntax: [ label ] ADDWF Operands: 0 f 127 d [0,1] Operation: (W) + (f) (dest) Status Affected: C, DC, Z Encoding: 00 W W f,d dfff ffff Description: Add the contents of the W register with register 'f'. If 'd' is 0, the result is stored in the W register. If 'd' is 1, the result is stored back in register 'f'. Words: Cycles: Example 0xA3 = 0x03 ANDWF AND W with f Syntax: [ label ] ANDWF Operands: 0 f 127 d [0,1] Operation: (W) .AND. (f) (dest) Status Affected: Z Encoding: 00 f,d 0101 dfff ffff Description: AND the W register with register 'f'. If 'd' is 0, the result is stored in the W register. If 'd' is 1, the result is stored back in register 'f'. 1 Words: 1 1 Cycles: 1 ADDWF FSR, 0 W = FSR = 0x17 0xC2 After Instruction W = FSR = Example ANDWF FSR, 1 Before Instruction Before Instruction DS30561B-page 72 = After Instruction 0x25 0111 0x5F Before Instruction 0x10 After Instruction W ANDLW 0xD9 0xC2 W = FSR = 0x17 0xC2 After Instruction W = FSR = 0x17 0x02 1999 Microchip Technology Inc. PIC12C67X BCF Bit Clear f BTFSC Bit Test, Skip if Clear Syntax: [ label ] BCF Syntax: [ label ] BTFSC f,b Operands: 0 f 127 0b7 Operands: 0 f 127 0b7 Operation: 0 (f<b>) Operation: skip if (f<b>) = 0 Status Affected: None Status Affected: None Encoding: 01 f,b 00bb bfff ffff Description: Bit 'b' in register 'f' is cleared. Words: 1 Cycles: 1 Example BCF Encoding: FLAG_REG = 0x47 bfff 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 2 cycle instruction. Words: 1 Cycles: 1(2) Before Instruction FLAG_REG = 0xC7 10bb Description: FLAG_REG, 7 After Instruction 01 Example HERE FALSE TRUE FLAG,1 PROCESS_CO DE BTFSC GOTO * * * Before Instruction PC = address HERE After Instruction if FLAG<1> = 0, PC = address TRUE if FLAG<1>=1, PC = address FALSE BSF Bit Set f Syntax: [ label ] BSF Operands: 0 f 127 0b7 Operation: 1 (f<b>) Status Affected: None Encoding: Description: 01 01bb bfff ffff Bit 'b' in register 'f' is set. Words: 1 Cycles: 1 Example f,b BSF FLAG_REG, 7 Before Instruction FLAG_REG = 0x0A After Instruction FLAG_REG = 0x8A 1999 Microchip Technology Inc. DS30561B-page 73 PIC12C67X BTFSS Bit Test f, Skip if Set CLRF Clear f Syntax: [ label ] BTFSS f,b Syntax: [ label ] CLRF Operands: 0 f 127 0b<7 Operands: 0 f 127 Operation: Operation: skip if (f<b>) = 1 00h (f) 1Z Status Affected: None Status Affected: Z Encoding: Description: 01 11bb bfff ffff If bit 'b' in register 'f' is '1', then the next instruction is skipped. If bit 'b' is '1', then the next instruction fetched during the current instruction execution, is discarded and a NOP is executed instead, making this a 2 cycle instruction. Encoding: 00 f 0001 The contents of register 'f' are cleared and the Z bit is set. Words: 1 Cycles: 1 Example CLRF FLAG_REG 1 Before Instruction Cycles: 1(2) After Instruction FLAG_REG HERE FALSE TRUE FLAG_REG Z FLAG,1 PROCESS_CO DE BTFSS GOTO * * * ffff Description: Words: Example 1fff = 0x5A = = 0x00 1 Before Instruction PC = address HERE After Instruction if FLAG<1> = 0, PC = address FALSE if FLAG<1> = 1, PC = address TRUE CLRW Clear W Syntax: [ label ] CLRW Operands: None Operation: (PC)+ 1 TOS, k PC<10:0>, (PCLATH<4:3>) PC<12:11> 00h (W) 1Z Status Affected: Z None Encoding: CALL Call Subroutine Syntax: [ label ] CALL k Operands: 0 k 2047 Operation: Status Affected: Encoding: Description: 10 kkkk kkkk Call Subroutine. First, return address (PC+1) is pushed onto the stack. The eleven bit immediate address is loaded into PC bits <10:0>. The upper bits of the PC are loaded from PCLATH. CALL is a two cycle instruction. Words: 1 Cycles: 2 Example 0kkk 00 0001 0000 0011 Description: W register is cleared. Zero bit (Z) is set. Words: 1 Cycles: 1 Example CLRW Before Instruction W = 0x5A After Instruction W Z HERE = = 0x00 1 CALL THER E Before Instruction PC = Address HERE After Instruction PC = Address THERE TOS = Address HERE+1 DS30561B-page 74 1999 Microchip Technology Inc. PIC12C67X CLRWDT Clear Watchdog Timer DECF Decrement f Syntax: [ label ] CLRWDT Syntax: [ label ] DECF f,d Operands: None Operands: Operation: 00h WDT 0 WDT prescaler, 1 TO 1 PD 0 f 127 d [0,1] Operation: (f) - 1 (dest) Status Affected: Z TO, PD Encoding: Status Affected: Encoding: Description: 00 0000 0110 0100 Description: 00 Words: 1 Words: 1 Cycles: 1 Cycles: 1 Example CNT Z WDT counter = ? WDT counter = WDT prescaler= TO = PD = COMF Complement f Syntax: [ label ] COMF Operands: 0 f 127 d [0,1] Operation: (f) (dest) Status Affected: Z 1001 dfff ffff Description: The contents of register 'f' are complemented. If 'd' is 0, the result is stored in W. If 'd' is 1, the result is stored back in register 'f'. Words: 1 Cycles: 1 COMF CNT Z 0x00 0 1 1 f,d = 0x13 REG1 W = = 0x13 0xEC = = 0x00 1 Decrement f, Skip if 0 Syntax: [ label ] DECFSZ f,d Operands: 0 f 127 d [0,1] Operation: (f) - 1 (dest); Status Affected: None Encoding: 00 skip if result = 0 1011 dfff ffff Description: The contents of register 'f' are decremented. If 'd' is 0, the result is placed in the W register. If 'd' is 1, the result is placed back in register 'f'. If the result is 0, the next instruction, which is already fetched, is discarded. A NOP is executed instead making it a two cycle instruction. Words: 1 Cycles: 1(2) Before Instruction REG1 0x01 0 DECFSZ REG1,0 After Instruction = = After Instruction After Instruction Example CNT, 1 DECF Before Instruction 00 ffff Before Instruction CLRWDT Encoding: dfff Decrement register 'f'. If 'd' is 0, the result is stored in the W register. If 'd' is 1, the result is stored back in register 'f'. CLRWDT instruction resets the Watchdog Timer. It also resets the prescaler of the WDT. Status bits TO and PD are set. Example 0011 Example HERE DECFSZ GOTO CONTINUE * * * CNT, 1 LOOP Before Instruction PC = address HERE After Instruction CNT if CNT PC if CNT PC 1999 Microchip Technology Inc. = = = = CNT - 1 0, address CONTINUE 0, address HERE+1 DS30561B-page 75 PIC12C67X GOTO Unconditional Branch INCFSZ Increment f, Skip if 0 Syntax: [ label ] Syntax: [ label ] Operands: 0 k 2047 Operands: Operation: k PC<10:0> PCLATH<4:3> PC<12:11> 0 f 127 d [0,1] Operation: (f) + 1 (dest), skip if result = 0 None Status Affected: None Status Affected: Encoding: GOTO k 10 1kkk kkkk kkkk Description: GOTO is an unconditional branch. The eleven bit immediate value is loaded into PC bits <10:0>. The upper bits of PC are loaded from PCLATH<4:3>. GOTO is a two cycle instruction. Words: 1 Cycles: 2 Example GOTO THERE After Instruction PC = Address THERE Encoding: 00 INCFSZ f,d 1111 dfff ffff Description: The contents of register 'f' are incremented. If 'd' is 0, the result is placed in the W register. If 'd' is 1, the result is placed back in register 'f'. If the result is 0, the next instruction, which is already fetched, is discarded. A NOP is executed instead making it a two cycle instruction. Words: 1 Cycles: 1(2) Example HERE INCFSZ GOTO CONTINUE * * * CNT, LOOP 1 Before Instruction PC = address HERE After Instruction CNT = if CNT= PC = if CNT PC = INCF Increment f Syntax: [ label ] Operands: 0 f 127 d [0,1] Operation: (f) + 1 (dest) Status Affected: Z Encoding: 00 INCF f,d 1010 dfff ffff Description: The contents of register 'f' are incremented. If 'd' is 0, the result is placed in the W register. If 'd' is 1, the result is placed back in register 'f'. Words: 1 Cycles: 1 Example INCF = = 0xFF 0 = = 0x00 1 After Instruction CNT Z DS30561B-page 76 Inclusive OR Literal with W Syntax: [ label ] Operands: 0 k 255 Operation: (W) .OR. k (W) Status Affected: Z Encoding: 11 IORLW k 1000 kkkk kkkk Description: The contents of the W register are OR'ed with the eight bit literal 'k'. The result is placed in the W register. Words: 1 Cycles: 1 IORLW 0x35 Before Instruction Before Instruction CNT Z IORLW Example CNT, 1 CNT + 1 0, address CONTINUE 0, address HERE +1 W = 0x9A After Instruction W Z = = 0xBF 1 1999 Microchip Technology Inc. PIC12C67X IORWF Inclusive OR W with f MOVF Move f Syntax: [ label ] Syntax: [ label ] Operands: 0 f 127 d [0,1] Operands: 0 f 127 d [0,1] Operation: (W) .OR. (f) (dest) Operation: (f) (dest) Status Affected: Z Status Affected: Z Encoding: 00 IORWF f,d 0100 dfff ffff Description: Inclusive OR the W register with register 'f'. If 'd' is 0, the result is placed in the W register. If 'd' is 1, the result is placed back in register 'f'. Words: 1 Cycles: 1 Example RESULT, 0 IORWF Before Instruction RESULT = W = Encoding: 00 1 Cycles: 1 FSR, 0 MOVF After Instruction W = value in FSR register Z =1 0x13 0x93 1 MOVWF Move W to f Move Literal to W Syntax: [ label ] Syntax: [ label ] Operands: 0 f 127 Operands: 0 k 255 Operation: (W) (f) Operation: k (W) Status Affected: None Status Affected: None Encoding: Description: Encoding: kkkk kkkk The eight bit literal 'k' is loaded into W register. The don't cares will assemble as 0's. Words: 1 Cycles: 1 Example MOVLW k 00xx 1fff Words: 1 Cycles: 1 MOVWF OPTION 0x5A 0xFF 0x4F After Instruction OPTION = W = 1999 Microchip Technology Inc. ffff Move data from W register to register 'f'. OPTION = W = After Instruction = 0000 f Before Instruction 0x5A W 00 MOVWF Description: Example MOVLW ffff Words: MOVLW 11 dfff The contents of register f are moved to a destination dependant upon the status of d. If d = 0, destination is W register. If d = 1, the destination is file register f itself. d = 1 is useful to test a file register since status flag Z is affected. After Instruction RESULT = W = Z = 1000 Description: Example 0x13 0x91 MOVF f,d 0x4F 0x4F DS30561B-page 77 PIC12C67X NOP No Operation RETFIE Return from Interrupt Syntax: [ label ] Syntax: [ label ] Operands: None Operands: None Operation: No operation Operation: Status Affected: None TOS PC, 1 GIE Status Affected: None Encoding: 00 NOP 0000 Description: No operation. Words: 1 Cycles: 1 Example 0xx0 0000 Encoding: 00 RETFIE 0000 0000 1001 Description: Return from Interrupt. Stack is POPed and Top of Stack (TOS) is loaded in the PC. Interrupts are enabled by setting Global Interrupt Enable bit, GIE (INTCON<7>). This is a two cycle instruction. Words: 1 Cycles: 2 NOP Example RETFIE After Interrupt PC = GIE = OPTION TOS 1 Load Option Register RETLW Return with Literal in W Syntax: [ label ] Syntax: [ label ] Operands: None Operands: 0 k 255 Operation: (W) OPTION Operation: Status Affected: None k (W); TOS PC Status Affected: None Encoding: Description: Words: Cycles: 00 OPTION 0000 0110 0010 The contents of the W register are loaded in the OPTION register. This instruction is supported for code compatibility with PIC16C5X products. Since OPTION is a readable/writable register, the user can directly address it. Encoding: Description: 11 RETLW k 01xx kkkk kkkk The W register is loaded with the eight bit literal 'k'. The program counter is loaded from the top of the stack (the return address). This is a two cycle instruction. 1 Words: 1 1 Cycles: 2 Example CALL TABLE;W contains table ;offset value * ;W now has table value * * ADDWF PC ;W = offset RETLW k1 ;Begin table RETLW k2 ; * * * RETLW kn ; End of table Example To maintain upward compatibility with future PIC12C67X products, do not use this instruction. TABLE Before Instruction W = 0x07 After Instruction W DS30561B-page 78 = value of k8 1999 Microchip Technology Inc. PIC12C67X RETURN Return from Subroutine RRF Rotate Right f through Carry Syntax: [ label ] Syntax: [ label ] Operands: None Operands: Operation: TOS PC 0 f 127 d [0,1] Status Affected: None Operation: See description below Status Affected: C Encoding: Description: 00 0000 0000 1000 Return from subroutine. The stack is POPed and the top of the stack (TOS) is loaded into the program counter. This is a two cycle instruction. Words: 1 Cycles: 2 Example RETURN Encoding: Description: RRF f,d 00 1100 dfff ffff The contents of register 'f' are rotated one bit to the right through the Carry Flag. If 'd' is 0, the result is placed in the W register. If 'd' is 1, the result is placed back in register 'f'. C Register f RETURN After Interrupt PC = TOS Words: 1 Cycles: 1 Example REG1, 0 RRF Before Instruction REG1 C = = 1110 0110 0 = = = 1110 0110 0111 0011 0 After Instruction REG1 W C RLF Rotate Left f through Carry Syntax: [ label ] Operands: 0 f 127 d [0,1] Operation: See description below Status Affected: C Encoding: Description: RLF 00 1101 dfff Words: 1 Cycles: 1 SLEEP Syntax: [ label ] Operands: None Operation: 00h WDT, 0 WDT prescaler, 1 TO, 0 PD Status Affected: TO, PD 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 the W register. If 'd' is 1, the result is stored back in register 'f'. C Example f,d Encoding: REG1,0 0000 0110 0011 Description: The power-down status bit, PD is cleared. Time-out status bit, TO is set. Watchdog Timer and its prescaler are cleared. The processor is put into SLEEP mode with the oscillator stopped. Words: 1 Cycles: 1 Example: SLEEP Register f RLF 00 SLEEP Before Instruction REG1 C = = 1110 0110 0 = = = 1110 0110 1100 1100 1 After Instruction REG1 W C 1999 Microchip Technology Inc. DS30561B-page 79 PIC12C67X SUBLW Syntax: Subtract W from Literal [ label ] SUBLW k SUBWF Syntax: Subtract W from f [ label ] SUBWF f,d Operands: 0 k 255 Operands: Operation: k - (W) (W) 0 f 127 d [0,1] Status Affected: C, DC, Z Operation: (f) - (W) (dest) Status Affected: C, DC, Z Encoding: 00 Encoding: Description: 11 110x kkkk kkkk The W register is subtracted (2's complement method) from the eight bit literal 'k'. The result is placed in the W register. Words: 1 Cycles: 1 Example 1: SUBLW 0x02 Before Instruction W C = = Example 2: = = = = Words: 1 Cycles: 1 Example 1: SUBWF 1 ? W C Example 3: = = REG1 W C = = REG1 W C 2 ? Example 2: = = = 1 2 1; result is positive = = = 2 2 ? After Instruction 3 ? 0xFF 0; result is nega- 3 2 ? Before Instruction REG1 W C 0 1; result is zero REG1 W C After Instruction W = C = tive = = = After Instruction Before Instruction W C REG1,1 Before Instruction 1 1; result is positive After Instruction ffff Subtract (2's complement method) W register from register 'f'. If 'd' is 0, the result is stored in the W register. If 'd' is 1, the result is stored back in register 'f'. Before Instruction W C dfff Description: After Instruction W C 0010 Example 3: = = = 0 2 1; result is zero Before Instruction REG1 W C = = = 1 2 ? After Instruction REG1 W C DS30561B-page 80 = = = 0xFF 2 0; result is negative 1999 Microchip Technology Inc. PIC12C67X SWAPF Swap Nibbles in f XORLW Exclusive OR Literal with W Syntax: [ label ] SWAPF f,d Syntax: [ label ] Operands: 0 f 127 d [0,1] Operands: 0 k 255 (f<3:0>) (dest<7:4>), (f<7:4>) (dest<3:0>) Operation: (W) .XOR. k (W) Status Affected: Z None Encoding: Operation: Status Affected: Encoding: Description: 00 1110 dfff ffff The upper and lower nibbles of register 'f' are exchanged. If 'd' is 0, the result is placed in W register. If 'd' is 1, the result is placed in register 'f'. Words: 1 Cycles: 1 11 1010 kkkk kkkk Description: The contents of the W register are XOR'ed with the eight bit literal 'k'. The result is placed in the W register. Words: 1 Cycles: 1 Example: XORLW 0xAF Before Instruction SWAPF REG, Example XORLW k 0 W Before Instruction REG1 = 0xB5 After Instruction = 0xA5 = = 0xA5 0x5A W = 0x1A After Instruction REG1 W TRIS Load TRIS Register Syntax: [ label ] TRIS Operands: 5f7 Operation: (W) TRIS register f; Status Affected: None Encoding: Description: 00 0000 f 0110 0fff The instruction is supported for code compatibility with the PIC16C5X products. Since TRIS registers are readable and writable, the user can directly address them. XORWF Exclusive OR W with f Syntax: [ label ] XORWF Operands: 0 f 127 d [0,1] Operation: (W) .XOR. (f) (dest) Status Affected: Z Encoding: 00 ffff Exclusive OR the contents of the W register with register 'f'. If 'd' is 0, the result is stored in the W register. If 'd' is 1, the result is stored back in register 'f'. 1 Words: 1 Cycles: 1 Cycles: 1 Example XORWF To maintain upward compatibility with future PIC12C67X products, do not use this instruction. dfff Description: Words: Example 0110 f,d REG 1 Before Instruction REG W = = 0xAF 0xB5 = = 0x1A 0xB5 After Instruction REG W 1999 Microchip Technology Inc. DS30561B-page 81 PIC12C67X NOTES: DS30561B-page 82 1999 Microchip Technology Inc. PIC12C67X 11.0 DEVELOPMENT SUPPORT PICmicro(R) The microcontrollers are supported with a full range of hardware and software development tools: * Integrated Development Environment - MPLAB(R) IDE Software * Assemblers/Compilers/Linkers - MPASM Assembler - MPLAB-C17 and MPLAB-C18 C Compilers - MPLINK/MPLIB Linker/Librarian * Simulators - MPLAB-SIM Software Simulator * Emulators - MPLAB-ICE Real-Time In-Circuit Emulator - PICMASTER(R)/PICMASTER-CE In-Circuit Emulator - ICEPICTM * In-Circuit Debugger - MPLAB-ICD for PIC16F877 * Device Programmers - PRO MATE II Universal Programmer - PICSTART Plus Entry-Level Prototype Programmer * Low-Cost Demonstration Boards - SIMICE - PICDEM-1 - PICDEM-2 - PICDEM-3 - PICDEM-17 - SEEVAL - KEELOQ 11.1 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: * Multiple functionality - editor - simulator - programmer (sold separately) - emulator (sold separately) * A full featured editor * A project manager * Customizable tool bar and key mapping * A status bar * On-line help 1999 Microchip Technology Inc. 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 - object code The ability to use MPLAB with Microchip's simulator, MPLAB-SIM, allows a consistent platform and the ability to easily switch from the cost-effective simulator to the full featured emulator with minimal retraining. 11.2 MPASM Assembler MPASM is a full featured universal macro assembler for all PICmicro MCU's. It can produce absolute code directly in the form of HEX files for device programmers, or it can generate relocatable objects for MPLINK. MPASM has a command line interface and a Windows shell and can be used as a standalone application on a Windows 3.x or greater system. MPASM generates relocatable object files, Intel standard HEX files, MAP files to detail memory usage and symbol reference, an absolute LST file which contains source lines and generated machine code, and a COD file for MPLAB debugging. MPASM features include: * MPASM and MPLINK are integrated into MPLAB projects. * MPASM allows user defined macros to be created for streamlined assembly. * MPASM allows conditional assembly for multi purpose source files. * MPASM directives allow complete control over the assembly process. 11.3 MPLAB-C17 and MPLAB-C18 C Compilers The MPLAB-C17 and MPLAB-C18 Code Development Systems are complete ANSI `C' compilers and integrated development environments for Microchip's PIC17CXXX and PIC18CXXX family of microcontrollers, respectively. These compilers provide powerful integration capabilities and ease of use not found with other compilers. For easier source level debugging, the compilers provide symbol information that is compatible with the MPLAB IDE memory display. DS30561B-page 83 PIC12C67X 11.4 MPLINK/MPLIB Linker/Librarian MPLINK is a relocatable linker for MPASM and MPLAB-C17 and MPLAB-C18. It can link relocatable objects from assembly or C source files along with precompiled libraries using directives from a linker script. MPLIB is a librarian for pre-compiled code to be used with MPLINK. When a routine from a library is called from another source file, only the modules that contains that routine will be linked in with the application. This allows large libraries to be used efficiently in many different applications. MPLIB manages the creation and modification of library files. MPLINK features include: * MPLINK works with MPASM and MPLAB-C17 and MPLAB-C18. * MPLINK allows all memory areas to be defined as sections to provide link-time flexibility. MPLIB features include: * MPLIB makes linking easier because single libraries can be included instead of many smaller files. * MPLIB helps keep code maintainable by grouping related modules together. * MPLIB commands allow libraries to be created and modules to be added, listed, replaced, deleted, or extracted. 11.5 MPLAB-SIM Software Simulator The MPLAB-SIM Software Simulator allows code development in a PC host environment by simulating the PICmicro series microcontrollers on an instruction level. On any given instruction, the data areas can be examined or modified and stimuli can be applied from a file or user-defined key press to any of the pins. The execution can be performed in single step, execute until break, or trace mode. MPLAB-SIM fully supports symbolic debugging using MPLAB-C17 and MPLAB-C18 and MPASM. The Software Simulator offers the flexibility to develop and debug code outside of the laboratory environment making it an excellent multi-project software development tool. 11.6 MPLAB-ICE High Performance Universal In-Circuit Emulator with MPLAB IDE The MPLAB-ICE Universal In-Circuit Emulator is intended to provide the product development engineer with a complete microcontroller design tool set for PICmicro microcontrollers (MCUs). Software control of MPLAB-ICE is provided by the MPLAB Integrated Development Environment (IDE), which allows editing, "make" and download, and source debugging from a single environment. DS30561B-page 84 Interchangeable processor modules allow the system to be easily reconfigured for emulation of different processors. The universal architecture of the MPLAB-ICE allows expansion to support new PICmicro microcontrollers. The MPLAB-ICE Emulator System has been designed as a real-time emulation system with advanced features that are generally found on more expensive development tools. The PC platform and Microsoft(R) Windows 3.x/95/98 environment were chosen to best make these features available to you, the end user. MPLAB-ICE 2000 is a full-featured emulator system with enhanced trace, trigger, and data monitoring features. Both systems use the same processor modules and will operate across the full operating speed range of the PICmicro MCU. 11.7 PICMASTER/PICMASTER CE The PICMASTER system from Microchip Technology is a full-featured, professional quality emulator system. This flexible in-circuit emulator provides a high-quality, universal platform for emulating Microchip 8-bit PICmicro microcontrollers (MCUs). PICMASTER systems are sold worldwide, with a CE compliant model available for European Union (EU) countries. 11.8 ICEPIC ICEPIC is a low-cost in-circuit emulation solution for the Microchip Technology PIC16C5X, PIC16C6X, PIC16C7X, and PIC16CXXX families of 8-bit one-timeprogrammable (OTP) microcontrollers. The modular system can support different subsets of PIC16C5X or PIC16CXXX products through the use of interchangeable personality modules or daughter boards. The emulator is capable of emulating without target application circuitry being present. 11.9 MPLAB-ICD In-Circuit Debugger Microchip's In-Circuit Debugger, MPLAB-ICD, is a powerful, low-cost run-time development tool. This tool is based on the flash PIC16F877 and can be used to develop for this and other PICmicro microcontrollers from the PIC16CXXX family. MPLAB-ICD utilizes the In-Circuit Debugging capability built into the PIC16F87X. This feature, along with Microchip's In-Circuit Serial Programming protocol, offers cost-effective in-circuit flash programming and debugging from the graphical user interface of the MPLAB Integrated Development Environment. This enables a designer to develop and debug source code by watching variables, single-stepping and setting break points. Running at full speed enables testing hardware in real-time. The MPLAB-ICD is also a programmer for the flash PIC16F87X family. 1999 Microchip Technology Inc. PIC12C67X 11.10 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 instructions and error messages, keys to enter commands and a modular detachable socket assembly to support various package types. In stand-alone mode the PRO MATE II can read, verify or program PICmicro devices. It can also set code-protect bits in this mode. 11.11 PICSTART Plus Entry Level Development System The PICSTART programmer is an easy-to-use, lowcost 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 supports all PICmicro devices with up to 40 pins. Larger pin count devices such as the PIC16C92X, and PIC17C76X may be supported with an adapter socket. PICSTART Plus is CE compliant. 11.12 SIMICE Entry-Level Hardware Simulator SIMICE is an entry-level hardware development system designed to operate in a PC-based environment with Microchip's simulator MPLAB-SIM. Both SIMICE and MPLAB-SIM run under Microchip Technology's MPLAB Integrated Development Environment (IDE) software. Specifically, SIMICE provides hardware simulation for Microchip's PIC12C5XX, PIC12CE5XX, and PIC16C5X families of PICmicro 8-bit microcontrollers. SIMICE works in conjunction with MPLAB-SIM to provide non-real-time I/O port emulation. SIMICE enables a developer to run simulator code for driving the target system. In addition, the target system can provide input to the simulator code. This capability allows for simple and interactive debugging without having to manually generate MPLAB-SIM stimulus files. SIMICE is a valuable debugging tool for entry-level system development. 11.13 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 1999 Microchip Technology Inc. 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 MPLAB-ICE 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. 11.14 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 MPLAB-ICE 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. 11.15 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 MPLAB-ICE 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 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. DS30561B-page 85 PIC12C67X 11.16 PICDEM-17 The PICDEM-17 is an evaluation board that demonstrates the capabilities of several Microchip microcontrollers, including PIC17C752, PIC17C756, PIC17C762, and PIC17C766. All necessary hardware is included to run basic demo programs, which are supplied on a 3.5-inch disk. A programmed sample is included, and the user may erase it and program it with the other sample programs using the PRO MATE II or PICSTART Plus device programmers and easily debug and test the sample code. In addition, PICDEM-17 supports down-loading of programs to and executing out of external FLASH memory on board. The PICDEM-17 is also usable with the MPLAB-ICE or PICMASTER emulator, and all of the sample programs can be run and modified using either emulator. Additionally, a generous prototype area is available for user hardware. 11.17 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 tradeoff analysis and reliability calculations. The total kit can significantly reduce time-to-market and result in an optimized system. 11.18 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. DS30561B-page 86 1999 Microchip Technology Inc. Software Tools Emulators 1999 Microchip Technology Inc. Programmers Debugger a PIC17C4X a a a a a a a PIC16C9XX a a a a a a a PIC16F8XX a a a a a PIC16C8X a a a a a a a PIC16C7XX a a a a a a a PIC16C7X a a a a a a a PIC16F62X a a a PIC16CXXX a a a a a PIC16C6X a a a a a a a PIC16C5X a a a a a a a PIC14000 a a a a a a PIC12CXXX a a a a a a a MCP2510 a a a a a a a a a a a a a a a a a a (R) * Contact the Microchip Technology Inc. web site at www.microchip.com for information on how to use the MPLAB -ICD In-Circuit Debugger (DV164001) with PIC16C62, 63, 64, 65, 72, 73, 74, 76, 77 ** Contact Microchip Technology Inc. for availability date. Development tool is available on select devices. MCP2510 CAN Developer's Kit MCRFXXX a a a 13.56 MHz Anticollision microID Developer's Kit 125 kHz Anticollision microID Developer's Kit 125 kHz microID Developer's Kit microIDTM Programmer's Kit KEELOQ Transponder Kit KEELOQ(R) Evaluation Kit PICDEM-17 a PICDEM-14A a PICDEM-3 a a a a PICDEM-2 a 24CXX/ 25CXX/ 93CXX a a PICDEM-1 a a a ** ** HCSXXX a SIMICE (R) MPLAB -ICD In-Circuit Debugger ICEPIC Low-Cost In-Circuit Emulator PICMASTER/PICMASTER-CE * a PRO MATE II Universal Programmer a PICSTARTPlus Low-Cost Universal Dev. Kit a a a * PIC17C7XX a a ** PIC18CXX2 a a MPASM/MPLINK (R) MPLAB -ICE TABLE 11-1: Demo Boards and Eval Kits (R) MPLAB Integrated Development Environment (R) MPLAB C17 Compiler (R) MPLAB C18 Compiler PIC12C67X DEVELOPMENT TOOLS FROM MICROCHIP DS30561B-page 87 PIC12C67X NOTES: DS30561B-page 88 1999 Microchip Technology Inc. PIC12C67X 12.0 ELECTRICAL SPECIFICATIONS FOR PIC12C67X Absolute Maximum Ratings Ambient temperature under bias...............................................................................................................-40 to +125C Storage temperature ............................................................................................................................. -65C to +150C Voltage on any pin with respect to VSS (except VDD and MCLR)................................................... -0.3V to (VDD + 0.3V) Voltage on VDD with respect to VSS ................................................................................................................ 0 to +7.0V Voltage on MCLR with respect to VSS (Note 2)..................................................................................................0 to +14V Total power dissipation (Note 1)...........................................................................................................................700 mW Maximum current out of VSS pin ...........................................................................................................................200 mA Maximum current into VDD pin ..............................................................................................................................150 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..........................................................................................................25 mA Maximum output current sourced by any I/O pin ....................................................................................................25 mA Maximum current sunk by GPIO pins combined ...................................................................................................100 mA Maximum current sourced by GPIO pins combined..............................................................................................100 mA Note 1: Power dissipation is calculated as follows: Pdis = VDD x {IDD - IOH} + {(VDD - VOH) x IOH} + (VOl x IOL). 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. 1999 Microchip Technology Inc. DS30561B-page 89 PIC12C67X FIGURE 12-1: PIC12C67X VOLTAGE-FREQUENCY GRAPH, -40C TA < 0C, +70C <TA +125C 6.0 5.5 5.0 VDD (Volts) 4.5 4.0 3.5 3.0 2.5 2.0 0 4 20 10 25 Frequency (MHz) Note 1: The shaded region indicates the permissible combinations of voltage and frequency. 2: The maximum rated speed of the part limits the permissible combinations of voltage and frequency. Please reference the Product Identification System section for the maximum rated speed of the parts. FIGURE 12-2: PIC12C67X VOLTAGE-FREQUENCY GRAPH, 0C TA +70C 6.0 5.5 5.0 VDD (Volts) 4.5 4.0 3.5 3.0 2.5 0 4 10 20 25 Frequency (MHz) Note 1: The shaded region indicates the permissible combinations of voltage and frequency. 2: The maximum rated speed of the part limits the permissible combinations of voltage and frequency. Please reference the Product Identification System section for the maximum rated speed of the parts. DS30561B-page 90 1999 Microchip Technology Inc. PIC12C67X FIGURE 12-3: PIC12LC67X VOLTAGE-FREQUENCY GRAPH, -40C TA +85C 6.0 5.5 5.0 4.5 VDD (Volts) 4.0 3.5 3.0 2.5 2.0 0 4 10 20 25 Frequency (MHz) Note 1: The shaded region indicates the permissible combinations of voltage and frequency. 2: The maximum rated speed of the part limits the permissible combinations of voltage and frequency. Please reference the Product Identification System section for the maximum rated speed of the parts. 1999 Microchip Technology Inc. DS30561B-page 91 PIC12C67X 12.1 DC Characteristics: PIC12C671/672 (Commercial, Industrial, Extended) PIC12CE673/674 (Commercial, Industrial, Extended) Standard Operating Conditions (unless otherwise specified) Operating Temperature 0C TA +70C (commercial) -40C TA +85C (industrial) -40C TA +125C (extended) DC CHARACTERISTICS Parm No. Characteristic Sym D001 Supply Voltage VDD D002 RAM Data Retention Voltage(2) VDR D003 VDD Start Voltage to ensure VPOR Power-on Reset D004 VDD Rise Rate to ensure Power-on Reset SVDD D010 Supply Current(3) IDD D010C D010A Min Typ(1) Max Units 3.0 5.5 Conditions V 1.5* V Device in SLEEP mode VSS V See section on Power-on Reset for details 0.05* V/ms See section on Power-on Reset for details -- 1.2 2.5 mA -- 1.2 2.5 mA -- 2.2 8 mA -- 19 29 A -- 19 37 A -- 32 60 A FOSC = 4MHz, VDD = 3.0V XT and EXTRC mode (Note 4) FOSC = 4MHz, VDD = 3.0V INTRC mode (Note 6) FOSC = 10MHz, VDD = 5.5V HS mode FOSC = 32kHz, VDD = 3.0V, WDT disabled LP mode, Commercial Temperature FOSC = 32kHz, VDD = 3.0V, WDT disabled LP mode, Industrial Temperature FOSC = 32kHz, VDD = 3.0V, WDT disabled LP mode, Extended Temperature D020 Power-down Current(5) D021 D021B IPD -- -- -- -- -- -- 0.25 0.25 2 0.5 0.8 3 6 7 14 8 9 16 A A A A A A VDD = 3.0V, Commercial, WDT disabled VDD = 3.0V, Industrial, WDT disabled VDD = 3.0V, Extended, WDT disabled VDD = 5.5V, Commercial, WDT disabled VDD = 5.5V, Industrial, WDT disabled VDD = 5.5V, Extended, WDT disabled D022 Watchdog Timer Current IWDT -- -- -- 2.2 2.2 4 5 6 11 A A A VDD = 3.0V, Commercial VDD = 3.0V, Industrial VDD = 3.0V, Extended D028 Supply Current(3) During read/write to EEPROM peripheral IEE -- 0.1 0.2 mA FOSC = 4MHz, VDD = 5.5V, SCL = 400kHz For PIC12CE673/674 only * These parameters are characterized but not tested. Note 1: Data in Typical ("Typ") column is based on characterization results at 25C. This data is for design guidance only and is not tested. 2: This is the limit to which VDD can be lowered in SLEEP mode without losing RAM data. 3: The supply current is mainly a function of the operating voltage and frequency. Other factors such as bus loading, oscillator type, bus rate, internal code execution pattern and temperature also have an impact on the current consumption. a) 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 VSS, T0CKI = VDD, MCLR = VDD; WDT disabled. b) For standby current measurements, the conditions are the same, except that the device is in SLEEP mode. 4: For EXTRC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula: Ir = VDD/2REXT (mA) with REXT in kOhm. 5: 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. 6: INTRC calibration value is for 4MHz nominal at 5V, 25C. DS30561B-page 92 1999 Microchip Technology Inc. PIC12C67X Standard Operating Conditions (unless otherwise specified) Operating Temperature 0C TA +70C (commercial) -40C TA +85C (industrial) -40C TA +125C (extended) DC CHARACTERISTICS Parm No. Characteristic LP Oscillator Operating Frequency INTRC/EXTRC Oscillator Operating Frequency XT Oscillator Operating Frequency HS Oscillator Operating Frequency Sym FOSC Min Typ(1) Max Units Conditions 0 200 kHz -- 4(6) MHz All temperatures 0 4 MHz All temperatures 0 10 MHz All temperatures All temperatures * These parameters are characterized but not tested. Note 1: Data in Typical ("Typ") column is based on characterization results at 25C. This data is for design guidance only and is not tested. 2: This is the limit to which VDD can be lowered in SLEEP mode without losing RAM data. 3: The supply current is mainly a function of the operating voltage and frequency. Other factors such as bus loading, oscillator type, bus rate, internal code execution pattern, and temperature also have an impact on the current consumption. a) 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 VSS, T0CKI = VDD, MCLR = VDD; WDT disabled. b) For standby current measurements, the conditions are the same, except that the device is in SLEEP mode. 4: For EXTRC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula: Ir = VDD/2REXT (mA) with REXT in kOhm. 5: 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. 6: INTRC calibration value is for 4MHz nominal at 5V, 25C. 1999 Microchip Technology Inc. DS30561B-page 93 PIC12C67X 12.2 DC Characteristics: PIC12LC671/672 (Commercial, Industrial) PIC12LCE673/674 (Commercial, Industrial) Standard Operating Conditions (unless otherwise specified) Operating temperature 0C TA +70C (commercial) -40C TA +85C (industrial) DC CHARACTERISTICS Param No. Characteristic Sym Min Typ Max Units 2.5 5.5 Conditions V D001 Supply Voltage VDD D002 RAM Data Retention Voltage(2) VDR 1.5* V Device in SLEEP mode D003 VDD Start Voltage to ensure Power-on Reset VPOR VSS V See section on Power-on Reset for details D004 VDD Rise Rate to ensure Power-on Reset SVDD D010 Supply Current(3) IDD 0.05* V/ms See section on Power-on Reset for details -- 0.4 2.1 mA D010C -- 0.4 2.1 mA D010A -- 15 33 A -- -- 0.2 0.2 5 6 A A VDD = 2.5V, Commercial VDD = 2.5V, Industrial Watchdog Timer Current IWDT -- 2.0 2.0 4 6 A A VDD = 2.5V, Commercial VDD = 2.5V, Industrial LP Oscillator Operating FOSC Frequency INTRC/EXTRC Oscillator Operating Frequency XT Oscillator Operating Frequency HS Oscillator Operating Frequency 0 200 kHz All temperatures -- 4(6) MHz All temperatures 0 4 MHz All temperatures 0 10 MHz All temperatures D020 D021 D021B Power-down Current(5) FOSC = 4MHz, VDD = 2.5V XT and EXTRC mode (Note 4) FOSC = 4MHz, VDD = 2.5V INTRC mode (Note 6) FOSC = 32kHz, VDD = 2.5V, WDT disabled LP mode, Industrial Temperature IPD * These parameters are characterized but not tested. Note 1: Data in Typical ("Typ") column is based on characterization results at 25C. This data is for design guidance only and is not tested. 2: This is the limit to which VDD can be lowered in SLEEP mode without losing RAM data. 3: The supply current is mainly a function of the operating voltage and frequency. Other factors such as bus loading, oscillator type, bus rate, internal code execution pattern, and temperature also have an impact on the current consumption. a) 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 VSS, T0CKI = VDD, MCLR = VDD; WDT disabled. b) For standby current measurements, the conditions are the same, except that the device is in SLEEP mode. 4: For EXTRC osc configuration, current through REXT is not included. The current through the resistor can be estimated by the formula: Ir = VDD/2REXT (mA) with REXT in kOhm. 5: 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. 6: INTRC calibration value is for 4MHz nominal at 5V, 25C. DS30561B-page 94 1999 Microchip Technology Inc. PIC12C67X 12.3 DC CHARACTERISTICS: DC CHARACTERISTICS Param No. Characteristic Input Low Voltage I/O ports with TTL buffer D030 D031 D032 with Schmitt Trigger buffer MCLR, GP2/T0CKI/AN2/INT (in EXTRC mode) OSC1 (in EXTRC mode) OSC1 (in XT, HS, and LP) Input High Voltage I/O ports with TTL buffer D033 D033 D040 D040A D041 with Schmitt Trigger buffer D042 MCLR, GP2/T0CKI/AN2/INT D042A OSC1 (XT, HS, and LP) D043 OSC1 (in EXTRC mode) Input Leakage Current (Notes 2, 3) D060 I/O ports PIC12C671/672 (Commercial, Industrial, Extended) PIC12CE673/674 (Commercial, Industrial, Extended) Standard Operating Conditions (unless otherwise specified) Operating temperature 0C TA +70C (commercial) -40C TA +85C (industrial) -40C TA +125C (extended) Operating voltage VDD range as described in DC spec Section 12.1 and Section 12.2. Sym Min Typ Max Units Conditions VIL -- -- -- -- 0.8V 0.15VDD 0.2VDD 0.2VDD V V V V VSS VSS -- -- 0.2VDD 0.3VDD V 2.0V 0.25VDD + 0.8V 0.8VDD 0.8VDD 0.7VDD 0.9VDD -- -- -- -- -- -- -- VDD VDD VDD VDD VDD VDD V V V V V V 4.5V VDD 5.5V otherwise For entire VDD range -- -- +1 A +30 +5 A A A VSS VPIN VDD, Pin at hi-impedance VSS VPIN VDD VSS VPIN VDD VSS VPIN VDD VIH IIL D061 GP3/MCLR (Note 5) D061A GP3 (Note 6) D062 GP2/T0CKI -- -- D063 OSC1 -- -- D070 GPIO weak pull-up current (Note 4) MCLR pull-up current Output Low Voltage I/O ports IPUR 50 250 -- -- -- 400 30 A A VOL -- -- 0.6 V -- -- 0.6 V -- -- 0.6 V -- -- 0.6 V D080 D080A D083 OSC2/CLKOUT D083A Note 1: 2: 3: 4: 5: 6: For 4.5V VDD 5.5V otherwise VSS VSS VSS VSS +5 +5 A Note 1 Note 1 Note 1 VSS VPIN VDD, XT, HS, and LP osc configuration VDD = 5V, VPIN = VSS VDD = 5V, VPIN = VSS IOL = 8.5 mA, VDD = 4.5V, -40C to +85C IOL = 7.0 mA, VDD = 4.5V, -40C to +125C IOL = 1.6 mA, VDD = 4.5V, -40C to +85C IOL = 1.2 mA, VDD = 4.5V, -40C to +125C Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. In EXTRC oscillator configuration, the OSC1/CLKIN pin is a Schmitt Trigger input. It is not recommended that the PIC12C67X 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 coming out of the pin. Does not include GP3. For GP3 see parameters D061 and D061A. This spec. applies to GP3/MCLR configured as external MCLR and GP3/MCLR configured as input with internal pull-up enabled. This spec. applies when GP3/MCLR is configured as an input with pull-up disabled. The leakage current of the MCLR circuit is higher than the standard I/O logic. 1999 Microchip Technology Inc. DS30561B-page 95 PIC12C67X DC CHARACTERISTICS Param No. Characteristic Output High Voltage I/O ports (Note 3) D090 Standard Operating Conditions (unless otherwise specified) Operating temperature 0C TA +70C (commercial) -40C TA +85C (industrial) -40C TA +125C (extended) Operating voltage VDD range as described in DC spec Section 12.1 and Section 12.2. Sym Min Typ Max Units Conditions VDD - 0.7 -- -- V VDD - 0.7 -- -- V VDD - 0.7 -- -- V VDD - 0.7 -- -- V COSC2 -- -- 15 pF CIO -- -- 50 pF VOH D090A D092 OSC2/CLKOUT D092A Capacitive Loading Specs on Output Pins OSC2 pin D100 D101 All I/O pins Note 1: 2: 3: 4: 5: 6: IOH = -3.0 mA, VDD = 4.5V, -40C to +85C IOH = -2.5 mA, VDD = 4.5V, -40C to +125C IOH = 1.3 mA, VDD = 4.5V, -40C to +85C IOH = 1.0 mA, VDD = 4.5V, -40C to +125C In XT and LP modes when external clock is used to drive OSC1. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. In EXTRC oscillator configuration, the OSC1/CLKIN pin is a Schmitt Trigger input. It is not recommended that the PIC12C67X 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 coming out of the pin. Does not include GP3. For GP3 see parameters D061 and D061A. This spec. applies to GP3/MCLR configured as external MCLR and GP3/MCLR configured as input with internal pull-up enabled. This spec. applies when GP3/MCLR is configured as an input with pull-up disabled. The leakage current of the MCLR circuit is higher than the standard I/O logic. DS30561B-page 96 1999 Microchip Technology Inc. PIC12C67X 12.4 DC CHARACTERISTICS: DC CHARACTERISTICS Param No. Characteristic Input Low Voltage I/O ports with TTL buffer D030 D031 D032 D033 D033 D040 D040A D041 D042 D042A D043 with Schmitt Trigger buffer MCLR, GP2/T0CKI/AN2/INT (in EXTRC mode) OSC1 (in EXTRC mode) OSC1 (in XT, HS, and LP) Input High Voltage I/O ports with TTL buffer PIC12LC671/672 (Commercial, Industrial) PIC12LCE673/674 (Commercial, Industrial) Standard Operating Conditions (unless otherwise specified) Operating temperature 0C TA +70C (commercial) -40C TA +85C (industrial) Operating voltage VDD range as described in DC spec Section 12.1 and Section 12.2. Sym Min Typ Max Units Conditions VIL VSS VSS VSS VSS -- -- -- -- 0.8V 0.15VDD 0.2VDD 0.2VDD V V V V For 4.5V VDD 5.5V otherwise VSS VSS -- -- 0.2VDD 0.3VDD V V Note 1 Note 1 2.0V 0.25VDD + 0.8V 0.8VDD 0.8VDD 0.7VDD 0.9VDD -- -- -- -- -- -- -- VDD VDD VDD VDD VDD VDD V V V V V V 4.5V VDD 5.5V otherwise For entire VDD range -- -- +1 A +30 +5 A A A Vss VPIN VDD, Pin at hi-impedance Vss VPIN VDD Vss VPIN VDD Vss VPIN VDD VIH D060 with Schmitt Trigger buffer MCLR, GP2/T0CKI/AN2/INT OSC1 (XT, HS, and LP) OSC1 (in EXTRC mode) Input Leakage Current (Notes 2, 3) I/O ports D061 D061A D062 GP3/MCLR (Note 5) GP3 (Note 6) GP2/T0CKI -- -- D063 OSC1 -- -- +5 +5 D070 GPIO weak pull-up current (Note 4) MCLR pull-up current Output Low Voltage I/O ports IPUR -- 50 -- 250 -- 400 30 A A VOL -- -- 0.6 V -- -- 0.6 V -- -- 0.6 V -- -- 0.6 V D080 D080A D083 OSC2/CLKOUT D083A Note 1: 2: 3: 4: 5: 6: IIL A Note 1 Vss VPIN VDD, XT, HS and LP osc configuration VDD = 5V, VPIN = VSS VDD = 5V, VPIN = VSS IOL = 8.5 mA, VDD = 4.5V, -40C to +85C IOL = 7.0 mA, VDD = 4.5V, -40C to +125C IOL = TBD, VDD = 4.5V, -40C to +85C IOL = TBD, VDD = 4.5V, -40C to +125C Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. In EXTRC oscillator configuration, the OSC1/CLKIN pin is a Schmitt Trigger input. It is not recommended that the PIC12C67X 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 coming out of the pin. Does not include GP3. For GP3 see parameters D061 and D061A. This spec. applies to GP3/MCLR configured as external MCLR and GP3/MCLR configured as input with internal pull-up enabled. This spec. applies when GP3/MCLR is configured as an input with pull-up disabled. The leakage current of the MCLR circuit is higher than the standard I/O logic. 1999 Microchip Technology Inc. DS30561B-page 97 PIC12C67X DC CHARACTERISTICS Param No. Characteristic Output High Voltage I/O ports (Note 3) D090 Standard Operating Conditions (unless otherwise specified) Operating temperature 0C TA +70C (commercial) -40C TA +85C (industrial) Operating voltage VDD range as described in DC spec Section 12.1 and Section 12.2. Sym Min Typ Max Units Conditions VOH VDD - 0.7 -- -- V VDD - 0.7 -- -- V VDD - 0.7 -- -- V VDD - 0.7 -- -- V COSC2 -- -- 15 pF CIO -- -- 50 pF D090A D092 OSC2/CLKOUT D092A Capacitive Loading Specs on Output Pins OSC2 pin D100 D101 All I/O pins Note 1: 2: 3: 4: 5: 6: IOH = -3.0 mA, VDD = 4.5V, -40C to +85C IOH = -2.5 mA, VDD = 4.5V, -40C to +125C IOH = TBD, VDD = 4.5V, -40C to +85C IOH = TBD, VDD = 4.5V, -40C to +125C In XT and LP modes when external clock is used to drive OSC1. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. In EXTRC oscillator configuration, the OSC1/CLKIN pin is a Schmitt Trigger input. It is not recommended that the PIC12C67X 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 coming out of the pin. Does not include GP3. For GP3 see parameters D061 and D061A. This spec. applies to GP3/MCLR configured as external MCLR and GP3/MCLR configured as input with internal pull-up enabled. This spec. applies when GP3/MCLR is configured as an input with pull-up disabled. The leakage current of the MCLR circuit is higher than the standard I/O logic. DS30561B-page 98 1999 Microchip Technology Inc. PIC12C67X 12.5 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 Lowercase letters (pp) and their meanings: pp cc CCP1 ck CLKOUT cs CS di SDI do SDO dt Data in io I/O port mc MCLR Uppercase letters and their meanings: S F Fall H High I Invalid (Hi-impedance) L Low I2C only AA BUF output access Bus free TCC:ST (I2C specifications only) CC HD Hold ST DAT DATA input hold STA START condition T Time osc rd rw sc ss t0 t1 wr OSC1 RD RD or WR SCK SS T0CKI T1CKI WR P R V Z Period Rise Valid Hi-impedance High Low High Low SU Setup STO STOP condition FIGURE 12-4: LOAD CONDITIONS Load condition 1 Load condition 2 VDD/2 RL CL Pin VSS CL Pin VSS RL = 464 CL = 50 pF 15 pF 1999 Microchip Technology Inc. for all pins except OSC2 for OSC2 output DS30561B-page 99 PIC12C67X 12.6 Timing Diagrams and Specifications FIGURE 12-5: EXTERNAL CLOCK TIMING Q4 Q1 Q2 Q3 Q4 Q1 OSC1 1 3 3 4 4 2 CLKOUT TABLE 12-1: Parameter No. CLOCK TIMING REQUIREMENTS Sym Characteristic Min Typ Max Units Conditions DC -- 4 MHz XT and EXTRC osc mode DC -- 4 MHz HS osc mode (PIC12CE67X-04) DC -- 10 MHz HS osc mode (PIC12CE67X-10) DC -- 200 kHz LP osc mode Oscillator Frequency DC -- 4 MHz EXTRC osc mode (Note 1) .455 -- 4 MHz XT osc mode 4 -- 4 MHz HS osc mode (PIC12CE67X-04) 4 -- 10 MHz HS osc mode (PIC12CE67X-10) 5 -- 200 kHz LP osc mode 1 TOSC External CLKIN Period 250 -- -- ns XT and EXTRC osc mode (Note 1) 250 -- -- ns HS osc mode (PIC12CE67X-04) 100 -- -- ns HS osc mode (PIC12CE67X-10) 5 -- -- s LP osc mode Oscillator Period 250 -- -- ns EXTRC osc mode (Note 1) 250 -- 10,000 ns XT osc mode 250 -- 250 ns HS osc mode (PIC12CE67X-04) 100 -- 250 ns HS osc mode (PIC12CE67X-10) 5 -- -- s LP osc mode 2 TCY Instruction Cycle Time (Note 1) 400 -- DC ns TCY = 4/FOSC 3 TosL, External Clock in (OSC1) High 50 -- -- ns XT oscillator TosH or Low Time 2.5 -- -- s LP oscillator 10 -- -- ns HS oscillator 4 TosR, External Clock in (OSC1) Rise -- -- 25 ns XT oscillator TosF or Fall Time -- -- 50 ns LP oscillator -- -- 15 ns HS oscillator Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: Instruction cycle period (TCY) equals four times the input oscillator time-base period. All specified values are based on characterization data for that particular oscillator type under standard operating conditions with the device executing code. Exceeding these specified limits may result in an unstable oscillator operation and/or higher than expected current consumption. All devices are tested to operate at "min." values with an external clock applied to the OSC1/CLKIN pin. When an external clock input is used, the "Max." cycle time limit is "DC" (no clock) for all devices. OSC2 is disconnected (has no loading) for the PIC12C67X. FOSC DS30561B-page 100 External CLKIN Frequency (Note 1) 1999 Microchip Technology Inc. PIC12C67X TABLE 12-2: CALIBRATED INTERNAL RC FREQUENCIES -PIC12C671, PIC12C672, PIC12CE673, PIC12CE674, PIC12LC671, PIC12LC672, PIC12LCE673, PIC12LCE674 AC Characteristics Parameter No. * Note 1: Standard Operating Conditions (unless otherwise specified) Operating Temperature 0C TA +70C (commercial), -40C TA +85C (industrial), -40C TA +125C (extended) Operating Voltage VDD range is described in Section 10.1 Min* Typ(1) Internal Calibrated RC Frequency 3.65 4.00 4.28 MHz VDD = 5.0V Internal Calibrated RC Frequency 3.55 4.00 4.31 MHz VDD = 2.5V Sym Characteristic Max* Units Conditions These parameters are characterized but not tested. Data in the Typical ("Typ") column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. 1999 Microchip Technology Inc. DS30561B-page 101 PIC12C67X FIGURE 12-6: CLKOUT AND I/O TIMING Q1 Q4 Q2 Q3 OSC1 11 10 CLKOUT 13 19 14 12 18 16 I/O Pin (input) 15 17 I/O Pin (output) new value old value 20, 21 Note: Refer to Figure 12-4 for load conditions. TABLE 12-3: CLKOUT AND I/O TIMING REQUIREMENTS Param Sym No. Characteristic Min Typ Max Units Conditions 10* TosH2ckL OSC1 to CLKOUT -- 75 200 ns Note 1 11* TosH2ckH OSC1 to CLKOUT -- 75 200 ns Note 1 12* TckR CLKOUT rise time -- 35 100 ns Note 1 13* TckF CLKOUT fall time -- 35 100 ns Note 1 14* TckL2ioV CLKOUT to Port out valid -- -- 0.5TCY + 20 ns Note 1 15* TioV2ckH Port in valid before CLKOUT TOSC + 200 -- -- ns Note 1 16* TckH2ioI Port in hold after CLKOUT 0 -- -- ns Note 1 17* TosH2ioV OSC1 (Q1 cycle) to Port out valid -- 50 150 ns 18* TosH2ioI OSC1 (Q2 cycle) to Port input invalid (I/O in hold time) 18A* PIC12C67X 100 -- -- ns PIC12LC67X 200 -- -- ns 0 -- -- ns PIC12C67X -- 10 40 ns PIC12LC67X -- -- 80 ns PIC12C67X -- 10 40 ns PIC12LC67X -- -- 80 ns 19* TioV2osH Port input valid to OSC1 (I/O in setup time) 20* TioR Port output rise time 20A* 21* TioF 21A* Port output fall time 22* Tinp GP2/INT pin high or low time TCY -- -- ns 23* Trbp GP0/GP1/GP3 change INT high or low time TCY -- -- ns * Note 1: These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. These parameters are asynchronous events not related to any internal clock edge. Measurements are taken in EXTRC and INTRC modes where CLKOUT output is 4 x TOSC. DS30561B-page 102 1999 Microchip Technology Inc. PIC12C67X FIGURE 12-7: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, AND POWER-UP TIMER TIMING VDD MCLR 30 Internal POR 33 PWRT Timeout 32 OSC Timeout Internal RESET Watchdog Timer RESET 36 34 31 34 I/O Pins TABLE 12-4: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER Parameter No. Sym * Characteristic Min Typ Max Units Conditions 30 TmcL MCLR Pulse Width (low) 2 -- -- s VDD = 5V, -40C to +125C 31* Twdt Watchdog Timer Time-out Period (No Prescaler) 7 18 33 ms VDD = 5V, -40C to +125C 32 Tost Oscillation Start-up Timer Period -- 1024TOSC -- -- TOSC = OSC1 period 33* Tpwrt Power up Timer Period 28 72 132 ms VDD = 5V, -40C to +125C 34 TIOZ I/O Hi-impedance from MCLR Low or Watchdog Timer Reset -- -- 2.1 s These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. 1999 Microchip Technology Inc. DS30561B-page 103 PIC12C67X FIGURE 12-8: TIMER0 CLOCK TIMINGS GP2/T0CKI 41 40 42 TMR0 Note: Refer to Figure 12-4 for load conditions. TABLE 12-5: Param No. Sym 40* Tt0H TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS Characteristic T0CKI High Pulse Width Min No Prescaler 0.5TCY + 20 -- -- ns 10 -- -- ns With Prescaler 41* Tt0L T0CKI Low Pulse Width No Prescaler 0.5TCY + 20 -- -- ns 10 -- -- ns TCY + 40 -- -- ns -- -- ns -- 7Tos c -- With Prescaler 42* Tt0P T0CKI Period No Prescaler With Prescaler 48 TCKE2tmr1 Delay from external clock edge to timer increment Typ Max Units Greater of: 20 or TCY + 40 N 2TOSC Conditions Must also meet parameter 42 Must also meet parameter 42 N = prescale value (2, 4,..., 256) * These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. TABLE 12-6: GPIO PULL-UP RESISTOR RANGES VDD (Volts) Temperature (C) Min Typ Max Units 2.5 -40 38K 42K 63K 25 42K 48K 63K 85 42K 49K 63K 125 50K 55K 63K -40 15K 17K 20K 25 18K 20K 23K 85 19K 22K 25K 125 22K 24K 28K GP0/GP1 5.5 GP3 2.5 5.5 * -40 285K 346K 417K 25 343K 414K 532K 85 368K 457K 532K 125 431K 504K 593K -40 247K 292K 360K 25 288K 341K 437K 85 306K 371K 448K 125 351K 407K 500K These parameters are characterized but not tested. DS30561B-page 104 1999 Microchip Technology Inc. PIC12C67X TABLE 12-7: Param No. Sym A01 NR A02 A/D CONVERTER CHARACTERISTICS: PIC12C671/672-04/PIC12CE673/674-04 (COMMERCIAL, INDUSTRIAL, EXTENDED) PIC12C671/672-10/PIC12CE673/674-10 (COMMERCIAL, INDUSTRIAL, EXTENDED) PIC12LC671/672-04/PIC12LCE673/674-04 (COMMERCIAL, INDUSTRIAL) Characteristic Resolution EABS Total absolute error Min Typ Max Units Conditions -- -- 8-bits bit VREF = VDD = 5.12V, VSS VAIN VREF -- -- < 1 LSb VREF = VDD = 5.12V, VSS VAIN VREF A03 EIL Integral linearity error -- -- < 1 LSb VREF = VDD = 5.12V, VSS VAIN VREF A04 EDL Differential linearity error -- -- < 1 LSb VREF = VDD = 5.12V, VSS VAIN VREF A05 EFS Full scale error -- -- < 1 LSb VREF = VDD = 5.12V, VSS VAIN VREF A06 EOFF Offset error -- -- < 1 LSb VREF = VDD = 5.12V, VSS VAIN VREF -- guaranteed (Note 3) -- -- 2.5V -- VDD + 0.3 V VSS - 0.3 -- VREF + 0.3 V -- -- 10.0 k PIC12C67X -- 180 -- A PIC12LC67X -- 90 -- A 10 -- 1000 A During VAIN acquisition. Based on differential of VHOLD to VAIN to charge CHOLD, see Section 8.1. -- -- 10 A During A/D Conversion cycle A10 -- Monotonicity A20 VREF Reference voltage A25 VAIN Analog input voltage A30 ZAIN Recommended impedance of analog voltage source A40 IAD A/D conversion current (VDD) A50 IREF VREF input current (Note 2) VSS VAIN VREF Average current consumption when A/D is on. (Note 1) * These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C 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 GP1 pin or VDD pin, whichever is selected as reference input. 3: The A/D conversion result never decreases with an increase in the Input Voltage, and has no missing codes. 1999 Microchip Technology Inc. DS30561B-page 105 PIC12C67X FIGURE 12-9: A/D CONVERSION TIMING BSF ADCON0, GO 134 1 TCY (TOSC/2)(1) 131 Q4 130 132 A/D CLK 7 A/D DATA 6 5 4 3 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 12-8: A/D CONVERSION REQUIREMENTS Param No. Sym Characteristic 130 TAD A/D clock period Min 1.6 -- -- s TOSC based, VREF 3.0V -- -- s TOSC based, VREF full range PIC12C67X 2.0 4.0 6.0 s A/D RC Mode PIC12LC67X 3.0 6.0 9.0 s A/D RC Mode 11 -- 11 TAD Note 2 20 -- s 5* -- -- s The minimum time is the amplifier setting time. This may be used if the "new" input voltage has not changed by more than 1 LSb (i.e., 20.0 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. 1.5 -- -- TAD 132 TACQ Acquisition time TSWC Conditions 2.0 Conversion time (not including S/H time) (Note 1) 135 Units PIC12LC67X TCNV TGO Max PIC12C67X 131 134 Typ Q4 to A/D clock start Switching from convert sample time * These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25C unless otherwise stated. These parameters are for design guidance only and are not tested. This specification ensured by design. Note 1: ADRES register may be read on the following TCY cycle. 2: See Section 8.1 for min. conditions. DS30561B-page 106 1999 Microchip Technology Inc. PIC12C67X TABLE 12-9: EEPROM MEMORY BUS TIMING REQUIREMENTS - PIC12CE673/674 ONLY. AC Characteristics Parameter Standard Operating Conditions (unless otherwise specified) Operating Temperature 0C TA +70C, Vcc = 3.0V to 5.5V (commercial) -40C TA +85C, Vcc = 3.0V to 5.5V (industrial) -40C TA +125C, Vcc = 4.5V to 5.5V (extended) Operating Voltage VDD range is described in Section 12.1 Symbol Min Max Units Conditions Clock frequency FCLK -- -- -- 100 100 400 kHz 4.5V Vcc 5.5V (E Temp range) 3.0V Vcc 4.5V 4.5V Vcc 5.5V Clock high time THIGH 4000 4000 600 -- -- -- ns 4.5V Vcc 5.5V (E Temp range) 3.0V Vcc 4.5V 4.5V Vcc 5.5V Clock low time TLOW 4700 4700 1300 -- -- -- ns 4.5V Vcc 5.5V (E Temp range) 3.0V Vcc 4.5V 4.5V Vcc 5.5V SDA and SCL rise time (Note 1) TR -- -- -- 1000 1000 300 ns 4.5V Vcc 5.5V (E Temp range) 3.0V Vcc 4.5V 4.5V Vcc 5.5V SDA and SCL fall time TF -- 300 ns (Note 1) START condition hold time THD:STA 4000 4000 600 -- -- -- ns 4.5V Vcc 5.5V (E Temp range) 3.0V Vcc 4.5V 4.5V Vcc 5.5V START condition setup time TSU:STA 4700 4700 600 -- -- -- ns 4.5V Vcc 5.5V (E Temp range) 3.0V Vcc 4.5V 4.5V Vcc 5.5V Data input hold time THD:DAT 0 -- ns (Note 2) Data input setup time TSU:DAT 250 250 100 -- -- -- ns 4.5V Vcc 5.5V (E Temp range) 3.0V Vcc 4.5V 4.5V Vcc 5.5V STOP condition setup time TSU:STO 4000 4000 600 -- -- -- ns 4.5V Vcc 5.5V (E Temp range) 3.0V Vcc 4.5V 4.5V Vcc 5.5V TAA -- -- -- 3500 3500 900 ns 4.5V Vcc 5.5V (E Temp range) 3.0V Vcc 4.5V 4.5V Vcc 5.5V Bus free time: Time the bus must be free before a new transmission can start TBUF 4700 4700 1300 -- -- -- ns 4.5V Vcc 5.5V (E Temp range) 3.0V Vcc 4.5V 4.5V Vcc 5.5V Output fall time from VIH minimum to VIL maximum TOF 20+0.1 CB 250 ns (Note 1), CB 100 pF Input filter spike suppression (SDA and SCL pins) TSP -- 50 ns (Notes 1, 3) Write cycle time TWC Output valid from clock (Note 2) Endurance -- 4 ms 1M -- cycles 25C, VCC = 5.0V, Block Mode (Note 4) Note 1: Not 100% tested. CB = total capacitance of one bus line in pF. 2: As a transmitter, the device must provide an internal minimum delay time to bridge the undefined region (minimum 300 ns) of the falling edge of SCL and avoid unintended generation of START or STOP conditions. 3: The combined TSP and VHYS specifications are due to new Schmitt Trigger inputs which provide improved noise spike suppression. This eliminates the need for a TI specification for standard operation. 4: This parameter is not tested but ensured by characterization. For endurance estimates in a specific application, please consult the Total Endurance Model which can be obtained on Microchip's website. 1999 Microchip Technology Inc. DS30561B-page 107 PIC12C67X NOTES: DS30561B-page 108 1999 Microchip Technology Inc. PIC12C67X 13.0 DC AND AC CHARACTERISTICS - PIC12C671/PIC12C672/PIC12LC671/ PIC12LC672/PIC12CE673/PIC12CE674/PIC12LCE673/PIC12LCE674 The graphs and tables provided in this section are for design guidance and are not tested. In some graphs or tables the data presented are outside specified operating range (i.e., outside specified VDD range). This is for information only and devices will 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 + 3) and (mean - 3) respectively, where is standard deviation. FIGURE 13-1: CALIBRATED INTERNAL RC FREQUENCY RANGE VS. TEMPERATURE (VDD = 5.0V) (INTERNAL RC IS CALIBRATED TO 25C, 5.0V) 4.50 4.50 4.40 4.40 4.30 4.30 4.20 Max. 4.20 Max. 4.10 Frequency (MHz) Frequency (MHz) FIGURE 13-2: CALIBRATED INTERNAL RC FREQUENCY RANGE VS. TEMPERATURE (VDD = 2.5V) (INTERNAL RC IS CALIBRATED TO 25C, 5.0V) 4.00 3.90 4.10 4.00 3.90 3.80 3.80 Min. 3.70 3.70 3.60 3.60 3.50 -40 3.50 -40 0 25 85 Temperature (Deg.C) 1999 Microchip Technology Inc. 125 Min. 0 25 85 125 Temperature (Deg.C) DS30561B-page 109 PIC12C67X TABLE 13-1: DYNAMIC IDD (TYPICAL) - WDT ENABLED, 25C Oscillator Frequency External RC 4 MHz Internal RC 4 MHz XT 4 MHz LP 32 kHz *Does not include current through external R&C. VDD = 2.5V VDD = 5.5V 400 A* 400 A 400 A 15 A 900 A* 900 A 900 A 60 A FIGURE 13-4: IOH vs. VOH, VDD = 2.5 V FIGURE 13-3: WDT TIMER TIME-OUT PERIOD vs. VDD -0 55 -1 50 -2 45 -3 WDT period (mS) 35 Max +125C IOH (mA) -4 40 Min +125C -5 Min +85C -6 Typ +25C 30 Max +85C -7 25 -8 20 Typ +25C -9 Max -40C -10 15 .5 .75 1.0 1.25 1.5 1.75 2.0 2.25 2.5 MIn -40C 10 0 2.5 3.5 4.5 5.5 VOH (Volts) 6.5 VDD (Volts) DS30561B-page 110 1999 Microchip Technology Inc. PIC12C67X FIGURE 13-5: IOH vs. VOH, VDD = 3.5 V FIGURE 13-7: IOL vs. VOL, VDD = 2.5 V 35 0 30 -5 IOH (mA) Max -40C Min +125C 25 -10 IOL (mA) Min +85C Typ +25C -15 20 Typ +25C 15 Max -40C -20 Min +85C 10 Min +125C -25 1.5 2.0 2.5 3.0 3.5 5 VOH (Volts) 0 0 FIGURE 13-6: IOH vs. VOH, VDD = 5.5 V 0.25 0.5 0.75 1.0 VOL (Volts) 0 FIGURE 13-8: IOL vs. VOL, VDD = 3.5 V -5 45 -10 IOH (mA) -15 n Mi 85 n+ i M -20 Ty Max -40C C 25 +1 2 p+ 40 C 35 C 5 30 -25 M ax -30 IOL (mA) -4 0 C Typ +25C -35 25 20 -40 3.5 4.0 4.5 5.0 5.5 15 Min +85C VOH (Volts) Min +125C 10 0 0 0.25 0.5 0.75 1.0 VOL (Volts) 1999 Microchip Technology Inc. DS30561B-page 111 PIC12C67X FIGURE 13-9: IOL vs. VOL, VDD = 5.5 V FIGURE 13-10: VTH (INPUT THRESHOLD VOLTAGE) OF GPIO PINS vs. VDD 55 1.8 Max -40C 50 Max (-40 to 125) VTH (Volts) 1.6 45 40 1.4 Typ (25) 1.2 35 IOL (mA) Typ +25C Min (-40 to 125) 1.0 30 0.8 25 Min +85C 20 15 Min +125C 0.6 0 2.5 3.5 4.5 VDD (Volts) 5.5 10 0 0 0.25 0.5 0.75 1.0 VOL (Volts) DS30561B-page 112 1999 Microchip Technology Inc. PIC12C67X FIGURE 13-11: VIL, VIH OF NMCLR AND T0CKI vs. VDD 3.5 VIH Max (-40 to 125) VIH Typ (25) VIH Min (-40 to 125) VIL, VIH (Volts) 3.0 2.5 2.0 VIL Max (-40 to 125) 1.5 VIL Typ (25) VIL Min (-40 to 125) 1.0 0.5 2.5 3.5 4.5 5.5 VDD (Volts) 1999 Microchip Technology Inc. DS30561B-page 113 PIC12C67X NOTES: DS30561B-page 114 1999 Microchip Technology Inc. PIC12C67X 14.0 PACKAGING INFORMATION 14.1 Package Marking Information 8-Lead PDIP (300 mil) MMMMMMMM XXXXXCDE AABB 12CE674 04/PSAZ 9925 8-Lead SOIC (208 mil) MMMMMMM XXXXXXX AABBCDE Example JW MM CE674 MMMMMM Legend: MM...M XX...X AA BB C D E * Example 12C671 04I/SM 9924SAZ 8-Lead Windowed Ceramic Side Brazed (300 mil) Note: Example 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. 1999 Microchip Technology Inc. DS30561B-page 115 PIC12C67X 8-Lead Plastic Dual In-line (P) - 300 mil (PDIP) E1 D 2 n 1 E A2 A L c A1 B1 p eB B Units Dimension Limits n p MIN INCHES* NOM MAX MILLIMETERS NOM 8 2.54 3.56 3.94 2.92 3.30 0.38 7.62 7.94 6.10 6.35 9.14 9.46 3.18 3.30 0.20 0.29 1.14 1.46 0.36 0.46 7.87 9.40 5 10 5 10 MIN Number of Pins 8 Pitch .100 Top to Seating Plane A .140 .155 .170 Molded Package Thickness A2 .115 .130 .145 Base to Seating Plane A1 .015 Shoulder to Shoulder Width E .300 .313 .325 Molded Package Width E1 .240 .250 .260 Overall Length D .360 .373 .385 Tip to Seating Plane L .125 .130 .135 c Lead Thickness .008 .012 .015 Upper Lead Width B1 .045 .058 .070 Lower Lead Width B .014 .018 .022 Overall Row Spacing eB .310 .370 .430 Mold Draft Angle Top 5 10 15 Mold Draft Angle Bottom 5 10 15 *Controlling Parameter Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. JEDEC Equivalent: MS-001 Drawing No. C04-018 DS30561B-page 116 MAX 4.32 3.68 8.26 6.60 9.78 3.43 0.38 1.78 0.56 10.92 15 15 1999 Microchip Technology Inc. PIC12C67X 8-Lead Plastic Small Outline (SM) - Medium, 208 mil (SOIC) E E1 p D 2 n 1 B c A2 A L Units Dimension Limits n p Number of Pins Pitch Overall Height Molded Package Thickness Standoff Overall Width Molded Package Width Overall Length Foot Length Foot Angle Lead Thickness Lead Width Mold Draft Angle Top Mold Draft Angle Bottom *Controlling Parameter A A2 A1 E E1 D L c B MIN .070 .069 .002 .300 .201 .202 .020 0 .008 .014 0 0 INCHES* NOM 8 .050 .075 .074 .005 .313 .208 .205 .025 4 .009 .017 12 12 A1 MAX .080 .078 .010 .325 .212 .210 .030 8 .010 .020 15 15 MILLIMETERS NOM 8 1.27 1.78 1.97 1.75 1.88 0.05 0.13 7.62 7.95 5.11 5.28 5.13 5.21 0.51 0.64 0 4 0.20 0.23 0.36 0.43 0 12 0 12 MIN MAX 2.03 1.98 0.25 8.26 5.38 5.33 0.76 8 0.25 0.51 15 15 Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" (0.254mm) per side. Drawing No. C04-056 1999 Microchip Technology Inc. DS30561B-page 117 PIC12C67X 8-Lead Ceramic Side Brazed Dual In-line with Window (JW) - 300 mil E1 W T D 2 n 1 U A A2 L A1 c B1 eB Units Dimension Limits n p Number of Pins Pitch Top to Seating Plane Top of Body to Seating Plane Standoff Package Width Overall Length Tip to Seating Plane Lead Thickness Upper Lead Width Lower Lead Width Overall Row Spacing Window Diameter Lid Length Lid Width *Controlling Parameter JEDC Equivalent: MS-015 Drawing No. C04-083 DS30561B-page 118 p B A A2 A1 E1 D L c B1 B eB W T U MIN .145 .103 .025 .280 .510 .130 .008 .050 .016 .296 .161 .440 .260 INCHES* NOM 8 .100 .165 .123 .035 .290 .520 .140 .010 .055 .018 .310 .166 .450 .270 MAX .185 .143 .045 .300 .530 .150 .012 .060 .020 .324 .171 .460 .280 MILLIMETERS NOM 8 2.54 3.68 4.19 2.62 3.12 0.64 0.89 7.11 7.37 12.95 13.21 3.30 3.56 0.20 0.25 1.27 1.40 0.41 0.46 7.52 7.87 4.09 4.22 11.18 11.43 6.60 6.86 MIN MAX 4.70 3.63 1.14 7.62 13.46 3.81 0.30 1.52 0.51 8.23 4.34 11.68 7.11 1999 Microchip Technology Inc. PIC12C67X APPENDIX A: COMPATIBILITY To convert code written for PIC16C5X to PIC12C67X, the user should take the following steps: 1. 2. 3. 4. 5. Remove any program memory page select operations (PA2, PA1, PA0 bits) for CALL, GOTO. Revisit any computed jump operations (write to PC or add to PC, etc.) to make sure page bits are set properly under the new scheme. Eliminate any data memory page switching. Redefine data variables to reallocate them. Verify all writes to STATUS, OPTION, and FSR registers since these have changed. Change reset vector to 0000h. 1999 Microchip Technology Inc. APPENDIX B: CODE FOR ACCESSING EEPROM DATA MEMORY Please refer to our web site at www.microchip.com for code availability. DS30561B-page 119 PIC12C67X NOTES: DS30561B-page 120 1999 Microchip Technology Inc. PIC12C67X INDEX A A/D Accuracy/Error ............................................................ 51 ADCON0 Register....................................................... 45 ADIF bit ....................................................................... 47 Analog Input Model Block Diagram............................. 48 Analog-to-Digital Converter......................................... 45 Configuring Analog Port Pins...................................... 49 Configuring the Interrupt ............................................. 47 Configuring the Module............................................... 47 Connection Considerations......................................... 51 Conversion Clock........................................................ 49 Conversions ................................................................ 50 Converter Characteristics ......................................... 105 Delays ......................................................................... 48 Effects of a Reset........................................................ 51 Equations .................................................................... 48 Flowchart of A/D Operation......................................... 52 GO/DONE bit .............................................................. 47 Internal Sampling Switch (Rss) Impedence ................ 48 Operation During Sleep .............................................. 51 Sampling Requirements.............................................. 48 Sampling Time ............................................................ 48 Source Impedence...................................................... 48 Time Delays ................................................................ 48 Transfer Function........................................................ 51 Absolute Maximum Ratings ................................................ 89 ADDLW Instruction ............................................................. 72 ADDWF Instruction ............................................................. 72 ADIE bit ............................................................................... 18 ADIF bit ............................................................................... 19 ADRES Register ..................................................... 13, 45, 47 ALU ....................................................................................... 7 ANDLW Instruction ............................................................. 72 ANDWF Instruction ............................................................. 72 Application Notes AN546 ......................................................................... 45 AN556 ......................................................................... 22 Architecture Harvard ......................................................................... 7 Overview ....................................................................... 7 von Neumann................................................................ 7 Assembler MPASM Assembler..................................................... 83 B BCF Instruction ................................................................... 73 Bit Manipulation .................................................................. 70 Block Diagrams Analog Input Model ..................................................... 48 On-Chip Reset Circuit ................................................. 57 Timer0......................................................................... 39 Timer0/WDT Prescaler ............................................... 42 Watchdog Timer.......................................................... 65 BSF Instruction ................................................................... 73 BTFSC Instruction............................................................... 73 BTFSS Instruction ............................................................... 74 1999 Microchip Technology Inc. C C bit .................................................................................... 15 CAL0 bit .............................................................................. 21 CAL1 bit .............................................................................. 21 CAL2 bit .............................................................................. 21 CAL3 bit .............................................................................. 21 CALFST bit ......................................................................... 21 CALL Instruction ................................................................. 74 CALSLW bit ........................................................................ 21 Carry bit ................................................................................ 7 Clocking Scheme................................................................ 10 CLRF Instruction................................................................. 74 CLRW Instruction................................................................ 74 CLRWDT Instruction........................................................... 75 Code Examples Changing Prescaler (Timer0 to WDT) ........................ 43 Changing Prescaler (WDT to Timer0) ........................ 43 Indirect Addressing..................................................... 23 Code Protection ............................................................ 53, 67 COMF Instruction................................................................ 75 Computed GOTO................................................................ 22 Configuration Bits ............................................................... 53 D DC and AC Characteristics............................................... 109 DC bit.................................................................................. 15 DC Characteristics PIC12C671/672, PIC12CE673/674 ............................ 92 PIC12LC671/672, PIC12LCE673/674 ........................ 94 DECF Instruction ................................................................ 75 DECFSZ Instruction............................................................ 75 Development Support ..................................................... 3, 83 Digit Carry bit ........................................................................ 7 Direct Addressing ............................................................... 23 E EEPROM Peripheral Operation .......................................... 33 Electrical Characteristics - PIC12C67X .............................. 89 Errata .................................................................................... 2 External Brown-out Protection Circuit................................. 61 External Power-on Reset Circuit......................................... 61 F Family of Devices ................................................................. 4 Features ............................................................................... 1 FSR Register .......................................................... 13, 14, 23 G General Description .............................................................. 3 GIE bit................................................................................. 62 GOTO Instruction................................................................ 76 GPIF bit .............................................................................. 64 GPIO............................................................................. 25, 59 GPIO Register .................................................................... 13 GPPU bit............................................................................. 16 DS30561B-page 121 PIC12C67X I K I/O Interfacing...................................................................... 25 I/O Ports .............................................................................. 25 I/O Programming Considerations........................................ 31 ID Locations ........................................................................ 53 INCF Instruction .................................................................. 76 INCFSZ Instruction.............................................................. 76 In-Circuit Serial Programming ....................................... 53, 67 INDF Register ............................................................... 14, 23 Indirect Addressing ............................................................. 23 Initialization Conditions for All Registers ............................. 59 Instruction Cycle.................................................................. 10 Instruction Flow/Pipelining .................................................. 10 Instruction Format ............................................................... 69 Instruction Set ADDLW ....................................................................... 72 ADDWF ....................................................................... 72 ANDLW ....................................................................... 72 ANDWF ....................................................................... 72 BCF ............................................................................. 73 BSF ............................................................................. 73 BTFSC ........................................................................ 73 BTFSS ........................................................................ 74 CALL ........................................................................... 74 CLRF........................................................................... 74 CLRW ......................................................................... 74 CLRWDT..................................................................... 75 COMF ......................................................................... 75 DECF .......................................................................... 75 DECFSZ...................................................................... 75 GOTO ......................................................................... 76 INCF............................................................................ 76 INCFSZ ....................................................................... 76 IORLW ........................................................................ 76 IORWF ........................................................................ 77 MOVF.......................................................................... 77 MOVLW ...................................................................... 77 MOVWF ...................................................................... 77 NOP ............................................................................ 78 OPTION ...................................................................... 78 RETFIE ....................................................................... 78 RETLW ....................................................................... 78 RETURN ..................................................................... 79 RLF ............................................................................. 79 RRF............................................................................. 79 SLEEP ........................................................................ 79 SUBLW ....................................................................... 80 SUBWF ....................................................................... 80 SWAPF ....................................................................... 81 TRIS ............................................................................ 81 XORLW ....................................................................... 81 XORWF....................................................................... 81 Section ........................................................................ 69 INTCON Register ................................................................ 17 INTEDG bit.......................................................................... 16 Internal Sampling Switch (Rss) Impedence ........................ 48 Interrupts ............................................................................. 53 A/D .............................................................................. 62 GP2/INT ...................................................................... 62 GPIO Port ................................................................... 62 Section ........................................................................ 62 TMR0 .......................................................................... 64 TMR0 Overflow ........................................................... 62 IORLW Instruction............................................................... 76 IORWF Instruction............................................................... 77 IRP bit ................................................................................. 15 KeeLoq Evaluation and Programming Tools ................... 86 DS30561B-page 122 L Loading of PC ..................................................................... 22 M MCLR............................................................................ 56, 59 Memory Data Memory .............................................................. 11 Program Memory ........................................................ 11 Register File Map - PIC12CE67X ............................... 12 MOVF Instruction................................................................ 77 MOVLW Instruction............................................................. 77 MOVWF Instruction ............................................................ 77 MPLAB Integrated Development Environment Software.... 83 N NOP Instruction .................................................................. 78 O Opcode ............................................................................... 69 OPTION Instruction ............................................................ 78 OPTION Register................................................................ 16 Orthogonal ............................................................................ 7 OSC selection..................................................................... 53 OSCCAL Register............................................................... 21 Oscillator EXTRC ....................................................................... 58 HS............................................................................... 58 INTRC......................................................................... 58 LP ............................................................................... 58 XT ............................................................................... 58 Oscillator Configurations..................................................... 54 Oscillator Types EXTRC ....................................................................... 54 HS............................................................................... 54 INTRC......................................................................... 54 LP ............................................................................... 54 XT ............................................................................... 54 P Package Marking Information ........................................... 115 Packaging Information ...................................................... 115 Paging, Program Memory................................................... 22 PCL..................................................................................... 70 PCL Register .......................................................... 13, 14, 22 PCLATH.............................................................................. 59 PCLATH Register ................................................... 13, 14, 22 PCON Register ............................................................. 20, 58 PD bit ............................................................................ 15, 56 PICDEM-1 Low-Cost PICmicro Demo Board ..................... 85 PICDEM-2 Low-Cost PIC16CXX Demo Board ................... 85 PICDEM-3 Low-Cost PIC16CXXX Demo Board ................ 85 PICSTART Plus Entry Level Development System ......... 85 PIE1 Register...................................................................... 18 Pinout Description - PIC12CE67X ........................................ 9 PIR1 Register ..................................................................... 19 POP .................................................................................... 22 POR .................................................................................... 58 Oscillator Start-up Timer (OST) ............................ 53, 58 Power Control Register (PCON)................................. 58 Power-on Reset (POR)................................... 53, 58, 59 Power-up Timer (PWRT) ...................................... 53, 58 Power-Up-Timer (PWRT) ........................................... 58 Time-out Sequence .................................................... 58 Time-out Sequence on Power-up ............................... 60 TO............................................................................... 56 Power.................................................................................. 56 1999 Microchip Technology Inc. PIC12C67X Power-down Mode (SLEEP) ............................................... 66 Prescaler, Switching Between Timer0 and WDT ................ 43 PRO MATE II Universal Programmer .............................. 85 Program Branches ................................................................ 7 Program Memory Paging......................................................................... 22 Program Verification ........................................................... 67 PS0 bit ................................................................................ 16 PS1 bit ................................................................................ 16 PS2 bit ................................................................................ 16 PSA bit ................................................................................ 16 PUSH .................................................................................. 22 R RC Oscillator ....................................................................... 55 Read Modify Write .............................................................. 31 Read-Modify-Write .............................................................. 31 Register File ........................................................................ 11 Registers Map PIC12C67X ......................................................... 12 Reset Conditions......................................................... 59 Reset............................................................................. 53, 56 Reset Conditions for Special Registers .............................. 59 RETFIE Instruction.............................................................. 78 RETLW Instruction .............................................................. 78 RETURN Instruction ........................................................... 79 RLF Instruction.................................................................... 79 RP0 bit .......................................................................... 11, 15 RP1 bit ................................................................................ 15 RRF Instruction ................................................................... 79 S SEEVAL Evaluation and Programming System ............... 86 Services One-Time-Programmable (OTP) .................................. 5 Quick-Turnaround-Production (QTP)............................ 5 Serialized Quick-Turnaround Production (SQTP)......... 5 SFR ..................................................................................... 70 SFR As Source/Destination ................................................ 70 SLEEP .......................................................................... 53, 56 SLEEP Instruction ............................................................... 79 Software Simulator (MPLAB-SIM) ...................................... 84 Special Features of the CPU .............................................. 53 Special Function Register PIC12C67X ................................................................. 13 Special Function Registers ................................................. 70 Special Function Registers, Section ................................... 12 Stack ................................................................................... 22 Overflows .................................................................... 22 Underflow.................................................................... 22 STATUS Register ............................................................... 15 SUBLW Instruction.............................................................. 80 SUBWF Instruction ............................................................. 80 SWAPF Instruction.............................................................. 81 T T0CS bit.............................................................................. 16 TAD ..................................................................................... 49 Timer0 RTCC.......................................................................... 59 Timers Timer0 Block Diagram .................................................... 39 External Clock .................................................... 41 External Clock Timing......................................... 41 Increment Delay ................................................. 41 Interrupt .............................................................. 39 Interrupt Timing .................................................. 40 Prescaler ............................................................ 42 Prescaler Block Diagram .................................... 42 Section ............................................................... 39 Switching Prescaler Assignment ........................ 43 Synchronization .................................................. 41 T0CKI ................................................................. 41 T0IF .................................................................... 64 Timing................................................................. 39 TMR0 Interrupt ................................................... 64 Timing Diagrams A/D Conversion ........................................................ 106 CLKOUT and I/O ...................................................... 102 External Clock Timing............................................... 100 Time-out Sequence .................................................... 60 Timer0 ........................................................................ 39 Timer0 Interrupt Timing .............................................. 40 Timer0 with External Clock......................................... 41 Wake-up from Sleep via Interrupt............................... 67 TO bit .................................................................................. 15 TOSE bit ............................................................................. 16 TRIS Instruction .................................................................. 81 TRIS Register ......................................................... 14, 25, 31 Two's Complement ............................................................... 7 U UV Erasable Devices............................................................ 5 W W Register ALU............................................................................... 7 Wake-up from SLEEP......................................................... 66 Watchdog Timer (WDT).................................... 53, 56, 59, 65 WDT ................................................................................... 59 Block Diagram ............................................................ 65 Period ......................................................................... 65 Programming Considerations ..................................... 65 Timeout....................................................................... 59 WWW, On-Line Support ....................................................... 2 X XORLW Instruction ............................................................. 81 XORWF Instruction............................................................. 81 Z Z bit..................................................................................... 15 Zero bit ................................................................................. 7 1999 Microchip Technology Inc. DS30561B-page 123 PIC12C67X NOTES: DS30561B-page 124 1999 Microchip Technology Inc. PIC12C67X 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 1-480-786-7302 for the rest of the world. 981103 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.microchip.com 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 1999 Microchip Technology Inc. Trademarks: The Microchip name, logo, PIC, PICmicro, PICSTART, PICMASTER, PRO MATE and MPLAB are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. FlexROM 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. DS30561B-page 125 PIC12C67X READER RESPONSE It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation can better serve you, please FAX your comments to the Technical Publications Manager at (480) 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: PIC12C67X Y N Literature Number: DS30561B 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? DS30561B-page 126 1999 Microchip Technology Inc. PIC12C67X PIC12C67X PRODUCT IDENTIFICATION SYSTEM Examples PART NO. -XX X /XX XXX Pattern: Special Requirements Package: P JW SM = 300 mil PDIP = 300 mil Windowed Ceramic Side Brazed = 208 mil SOIC Temperature Range: I E = 0C to +70C = -40C to +85C = -40C to +125C Frequency Range: 04 10 = 4 MHz/200 kHz = 10 MHz Device PIC12CE673 PIC12CE674 PIC12LCE673 PIC12LCE674 PIC12C671 PIC12C672 PIC12C671T (Tape & reel for SOIC only) PIC12C672T (Tape & reel for SOIC only) PIC12LC671 PIC12LC672 PIC12LC671T (Tape & reel for SOIC only) PIC12LC672T (Tape & reel for SOIC only) a) PIC12CE673-04/P Commercial Temp., PDIP Package, 4 MHz, normal VDD limits b) PIC12CE673-04I/P Industrial Temp., PDIP package, 4 MHz, normal VDD limits c) PIC12CE673-10I/P Industrial Temp., PDIP package, 10 MHz, normal VDD limits d) PIC12C671-04/P Commercial Temp., PDIP Package, 4 MHz, normal VDD limits e) PIC12C671-04I/SM Industrial Temp., SOIC package, 4 MHz, normal VDD limits f) PIC12C671-04I/P Industrial Temp., PDIP package, 4 MHz, normal VDD limits * JW Devices are UV erasable and can be programmed to any device configuration. JW Devices meet the electrical requirement of each oscillator type (including LC devices). Sales and Support Data Sheets Products supported by a preliminary Data Sheet may have an errata sheet describing minor operational differences and recommended workarounds. To determine if an errata sheet exists for a particular device, please contact one of the following: 1. 2. 3. Your local Microchip sales office The Microchip Corporate Literature Center U.S. FAX: (480) 786-7277 The Microchip Worldwide Site (www.microchip.com) Please specify which device, revision of silicon and Data Sheet (include Literature #) you are using. New Customer Notification System Register on our web site (www.microchip.com/cn) to receive the most current information on our products. 1999 Microchip Technology Inc. DS30561B-page 127 Note the following details of the code protection feature on PICmicro(R) MCUs. * * * * * * The PICmicro family meets the specifications contained in the Microchip Data Sheet. Microchip believes that its family of PICmicro microcontrollers is one of the most secure products of its kind on the market today, when used in the intended manner and under normal conditions. There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our knowledge, require using the PICmicro microcontroller in a manner outside the operating specifications contained in the data sheet. The person doing so may be engaged in theft of intellectual property. Microchip is willing to work with the customer who is concerned about the integrity of their code. Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not mean that we are guaranteeing the product as "unbreakable". Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our product. If you have any further questions about this matter, please contact the local sales office nearest to you. Information contained in this publication regarding device applications and the like is intended through suggestion only and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. No representation or warranty is given and no liability is assumed by Microchip Technology Incorporated with respect to the accuracy or use of such information, or infringement of patents or other intellectual property rights arising from such use or otherwise. Use of Microchip's products as critical components in life support systems is not authorized except with express written approval by Microchip. No licenses are conveyed, implicitly or otherwise, under any intellectual property rights. Trademarks The Microchip name and logo, the Microchip logo, FilterLab, KEELOQ, microID, MPLAB, PIC, PICmicro, PICMASTER, PICSTART, PRO MATE, SEEVAL and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. dsPIC, ECONOMONITOR, FanSense, FlexROM, fuzzyLAB, In-Circuit Serial Programming, ICSP, ICEPIC, microPort, Migratable Memory, MPASM, MPLIB, MPLINK, MPSIM, MXDEV, PICC, PICDEM, PICDEM.net, rfPIC, Select Mode and Total Endurance are trademarks of Microchip Technology Incorporated in the U.S.A. Serialized Quick Turn Programming (SQTP) is a service mark of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are property of their respective companies. (c) 2002, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper. Microchip received QS-9000 quality system certification for its worldwide headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona in July 1999. The Company's quality system processes and procedures are QS-9000 compliant for its PICmicro(R) 8-bit MCUs, KEELOQ(R) code hopping devices, Serial EEPROMs and microperipheral products. In addition, Microchip's quality system for the design and manufacture of development systems is ISO 9001 certified. 2002 Microchip Technology Inc. M WORLDWIDE SALES AND SERVICE AMERICAS ASIA/PACIFIC Japan Corporate Office Australia 2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-792-7200 Fax: 480-792-7277 Technical Support: 480-792-7627 Web Address: http://www.microchip.com Microchip Technology Australia Pty Ltd Suite 22, 41 Rawson Street Epping 2121, NSW Australia Tel: 61-2-9868-6733 Fax: 61-2-9868-6755 Microchip Technology Japan K.K. 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India Liaison Office Divyasree Chambers 1 Floor, Wing A (A3/A4) No. 11, O'Shaugnessey Road Bangalore, 560 025, India Tel: 91-80-2290061 Fax: 91-80-2290062 Korea Microchip Technology Korea 168-1, Youngbo Bldg. 3 Floor Samsung-Dong, Kangnam-Ku Seoul, Korea 135-882 Tel: 82-2-554-7200 Fax: 82-2-558-5934 Singapore Microchip Technology Singapore Pte Ltd. 200 Middle Road #07-02 Prime Centre Singapore, 188980 Tel: 65-334-8870 Fax: 65-334-8850 Taiwan Microchip Technology Taiwan 11F-3, No. 207 Tung Hua North Road Taipei, 105, Taiwan Tel: 886-2-2717-7175 Fax: 886-2-2545-0139 EUROPE Denmark Microchip Technology Nordic ApS Regus Business Centre Lautrup hoj 1-3 Ballerup DK-2750 Denmark Tel: 45 4420 9895 Fax: 45 4420 9910 France 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 Germany Microchip Technology GmbH Gustav-Heinemann Ring 125 D-81739 Munich, Germany Tel: 49-89-627-144 0 Fax: 49-89-627-144-44 Italy 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 United Kingdom Arizona Microchip Technology Ltd. 505 Eskdale Road Winnersh Triangle Wokingham Berkshire, England RG41 5TU Tel: 44 118 921 5869 Fax: 44-118 921-5820 01/18/02 2002 Microchip Technology Inc.