PIC16C8X 8-Bit CMOS EEPROM Microcontrollers Pin Diagram Devices Included in this Data Sheet PIC16C83 PIC16CR83 PIC16C84 PIC16C84A PIC16CR84 Extended voltage range devices available (PIC16LC8X) PDIP, SOIC High Performance RISC CPU Features • Only 35 single word instructions to learn • All instructions single cycle (400 ns @ 10 MHz) except for program branches which are two-cycle • Operating speed: DC - 10 MHz clock input DC - 400 ns instruction cycle RA2 •1 18 RA1 RA3 2 17 RA0 RA4/T0CKI 3 16 OSC1/CLKIN MCLR 4 15 OSC2/CLKOUT VSS 5 14 VDD RB0/INT 6 13 RB7 RB1 7 12 RB6 RB2 8 11 RB5 RB3 9 10 RB4 PIC16C8X • • • • • • Memory Device Freq Max. Data Program RAM EEPROM PIC16C83 512 words 36 PIC16CR83 512 words† 36 PIC16C84 1 K-words 36 PIC16C84A 1 K-words 68 PIC16CR84 1 K-words† 68 † ROM Program Memory Devices 64 64 64 64 64 10 MHz 10 MHz 10 MHz 10 MHz 10 MHz • • • • • • 14-bit wide instructions 8-bit wide data path 15 special function hardware registers Eight-level deep hardware stack Direct, indirect and relative addressing modes Four interrupt sources: - External RB0/INT pin - TMR0 timer overflow - PORTB<7:4> interrupt on change - Data EEPROM write complete • 1,000,000 data memory EEPROM ERASE/WRITE cycles - Typical • EEPROM Data Retention > 40 years Peripheral Features • 13 I/O pins with individual direction control • High current sink/source for direct LED drive - 25 mA sink max. per pin - 20 mA source max. per pin • TMR0: 8-bit timer/counter with 8-bit programmable prescaler Special Microcontroller Features • • • • • • • • Power-on Reset (POR) Power-up Timer (PWRT) Oscillator Start-up Timer (OST) Watchdog Timer (WDT) with its own on-chip RC oscillator for reliable operation Code-protection Power saving SLEEP mode Selectable oscillator options Serial In-System Programming - via two pins (ROM devices support only Data EEPROM programming) CMOS Technology • Low-power, high-speed CMOS EEPROM technology • Fully static design • Wide operating voltage range: - Commercial: 2.0V to 6.0V - Industrial: 2.0V to 6.0V • Low power consumption: - < 2 mA typical @ 5V, 4 MHz - 15 µA typical @ 2V, 32 kHz - < 1 µA typical standby current @ 2V (all devices except PIC16C84) 1995 Microchip Technology Inc. DS30081F-page 1 Thi d t t d ith F M k 404 PIC16C8X Table of Contents 1.0 General Description................................................................................................................................................3 2.0 PIC16C8X Device Varieties ....................................................................................................................................5 3.0 Architectural Overview............................................................................................................................................7 4.0 Memory Organization ...........................................................................................................................................11 5.0 I/O Ports................................................................................................................................................................21 6.0 Timer0 Module and TMR0 Register......................................................................................................................27 7.0 Data EEPROM Memory .......................................................................................................................................33 8.0 Special Features of the CPU ................................................................................................................................37 9.0 Instruction Set Summary ......................................................................................................................................53 10.0 Development Support ...........................................................................................................................................65 11.0 Electrical Characteristics for PIC16C84................................................................................................................71 12.0 DC & AC Characteristics Graphs/Tables for PIC16C84........................................................................................81 13.0 Electrical Characteristics for PIC16C83, PIC16CR83, PIC16C84A and PIC16CR84 ..........................................95 14.0 DC & AC Characteristics Graphs/Tables for PIC16C83, PIC16CR83, PIC16C84A, and PIC16CR84 ...............107 15.0 Packaging Information ........................................................................................................................................109 Appendix A: Changes ...............................................................................................................................................113 Appendix B: Compatibility.........................................................................................................................................113 Appendix C: What’s New ..........................................................................................................................................114 Appendix D: What’s Changed...................................................................................................................................114 Appendix E: PIC16C84 Conversion Considerations.................................................................................................115 Appendix F: PIC16/17 Microcontrollers ....................................................................................................................117 Index.....................................................................................................................................................125 Connecting to Microchip BBS ..............................................................................................................129 Reader Response ................................................................................................................................130 To Our Valued Customers We constantly strive to improve the quality of all our products and documentation. We have spent an exceptional amount of time to ensure that these documents are 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 use the reader response form in the back of this data sheet to inform us. We appreciate your assistance in making this a better document. To assist you in the use of this document, Appendix C contains a list of new information in this data sheet, while Appendix D contains information that has changed DS30081F-page 2 1995 Microchip Technology Inc. PIC16C8X 1.0 GENERAL DESCRIPTION The PIC16C8X is a group in the PIC16CXX family of low-cost, high-performance, CMOS, fully-static, 8-bit microcontrollers. This group contains the following devices: • • • • • PIC16C83 PIC16CR83 PIC16C84 PIC16C84A PIC16CR84 All PIC16/17 microcontrollers employ an advanced RISC architecture. PIC16CXX devices 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 a separate 8-bit wide data bus. 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. PIC16C8X microcontrollers typically achieve a 2:1 code compression and up to a 2:1 speed improvement (at 10 MHz) over other 8-bit microcontrollers in their class. The PIC16C8X has up to 68 bytes of RAM, 64 bytes of Data EEPROM memory, and 13 I/O pins. A timer/counter is also available. The PIC16CXX family has special features to reduce external components, thus reducing cost, enhancing system reliability and reducing power consumption. There are four oscillator options, of which the single pin RC oscillator provides a low-cost solution, the LP oscillator minimizes power consumption, XT is a standard crystal, and the HS is for High Speed crystals. The SLEEP (power-down) mode offers power saving. The user can wake the chip from sleep through several external and internal interrupts and resets. A highly reliable Watchdog Timer with its own on-chip RC oscillator provides protection against software lock-up. The devices with EEPROM program memory allows the same device package to be used for prototyping and production. In-circuit reprogrammability allows the code to be updated without the device being removed from the end application. This is useful in the development of many applications where the device may not be easily accessible, but the prototypes may require code updates. This is also useful for remote applications where the code may need to be updated (such as rate information). Table 1-1 lists the features of the PIC16C8X, and Appendix F: list the features of all of the Microchip microcontrollers. A simplified block diagram of the PIC16C8X is shown in Figure 3-1. The PIC16C8X fits perfectly in applications ranging from high speed automotive and appliance motor control to low-power remote sensors, electronic locks, security devices and smart cards. The EEPROM technology makes customization of application programs (transmitter codes, motor speeds, receiver frequencies, security codes, etc.) extremely fast and convenient. The small footprint packages make this microcontroller series perfect for all applications with space limitations. Low-cost, low-power, high performance, ease of use and I/O flexibility make the PIC16C8X very versatile even in areas where no microcontroller use has been considered before (e.g., timer functions, serial communication, capture and compare, PWM functions and co-processor applications). The serial in-system programming feature (via two pins) offers flexibility of customizing the product after complete assembly and testing. This feature can be used to serialize a product, store calibration data, or program the device with the current firmware before shipping. 1.1 Family and Upward Compatibility Those users familiar with the PIC16C5X family of microcontrollers will realize that this is an enhanced version of the PIC16C5X architecture. Please refer to Appendix A for a detailed list of enhancements. Code written for PIC16C5X can be easily ported to the PIC16C8X (Appendix B). 1.2 Development Support The PIC16CXX family is supported by a full-featured macro assembler, a software simulator, an in-circuit emulator, a low-cost development programmer and a full-featured programmer. A “C” compiler and fuzzy logic support tools are also available. 1995 Microchip Technology Inc. DS30081F-page 3 Thi d t t d ith F M k 404 PIC16C8X PIC16C8X FAMILIES OF DEVICES Clock Memory ) Hz em am p O gr um xim a M PIC16C83(1) 10 PIC16CR83(1) PIC16C84 y or em M O R EP E a at M RO M D a at D ) es o Pr e qu e Fr M t by ( M ) es yt (b ( le O PR u od EE er ge rc ou M S pt ru r te m Ti ) ts ol es s) In (V an ge ns y nc of Features o (M tio a er ta ol Pi n Peripherals ry I/O TABLE 1-1: V es R ag k ac P 512 — 36 64 TMR0 4 13 2.0-6.0 18-pin DIP, SOIC 10 — 512 36 64 TMR0 4 13 2.0-6.0 18-pin DIP, SOIC 10 1K — 36 64 TMR0 4 13 2.0-6.0 18-pin DIP, SOIC PIC16C84A(1) 10 1K — 68 64 TMR0 4 13 2.0-6.0 18-pin DIP, SOIC PIC16CR84(1) 10 — 1K 68 64 TMR0 4 13 2.0-6.0 18-pin DIP, SOIC Notes: - All PIC16/17 family devices have Power-on Reset, selectable Watchdog Timer, selectable code protect, and high I/O current capability. - All PIC16CXX family devices use serial programming with clock pin RB6 and data pin RB7. 1: Please contact your local sales office for availability of these devices. DS30081F-page 4 1995 Microchip Technology Inc. PIC16C8X 2.0 PIC16C8X 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 this section. When placing orders, please use the “PIC16C8X Product Identification System” at the back of this data sheet to specify the correct part number. There are four device “types” as indicated in the device number. 1. 2. 3. 4. C, as in PIC16C84. These devices have EEPROM program memory and operate over the standard voltage range. LC, as in PIC16LC84. These devices have EEPROM program memory and operate over an extended voltage range. CR, as in PIC16CR83. These devices have ROM program memory and operate over the standard voltage range. LCR, as in PIC16LCR84. These devices have ROM program memory and operate over an extended voltage range. When discussing memory maps and other architectural features, the use of C (CR) also implies the LC (LCR) versions. 2.1 Electrically Erasable Devices These devices are offered in the lower cost plastic package, even though the device can be erased and reprogrammed. This allows the same device to be used for prototype development and pilot programs as well as production. A further advantage of the electrically erasable version is that they can be erased and reprogrammed in-circuit, or by device programmers, such as Microchip's PICSTART or PRO MATE programmers. 2.2 Quick-Turnaround-Production (QTP) Devices Microchip offers a QTP Programming Service for factory production orders. This service is made available for users who choose not to program a medium to high quantity of units and whose code patterns have stabilized. The devices have all EEPROM locations and configuration options already programmed by the factory. Certain code and prototype verification procedures do apply before production shipments are available. For information on submitting a QTP code, please contact your Microchip Regional Sales Office. 2.3 Serialized Quick-TurnaroundProduction (SQTP SM ) Devices Microchip offers the 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. For information on submitting a SQTP code, please contact your Microchip Regional Sales Office. 2.4 ROM Devices Some of Microchip’s devices have a corresponding device where the program memory is a ROM. These devices give a cost savings over Microchip’s traditional user programmed devices (EPROM, EEPROM). ROM devices (PIC16CR8X) do not allow serialization information in the program memory space. The user may program this information into the Data EEPROM. For information on submitting a ROM code, please contact your Microchip Regional Sales Office. 1995 Microchip Technology Inc. DS30081F-page 5 Thi d t t d ith F M k 404 PIC16C8X NOTES: DS30081F-page 6 1995 Microchip Technology Inc. PIC16C8X 3.0 ARCHITECTURAL OVERVIEW The high performance of the PIC16CXX family can be attributed to a number of architectural features commonly found in RISC microprocessors. To begin with, the PIC16CXX uses a Harvard architecture. This architecture has the program and data are accessed from separate memories. So the device has a program memory bus and a data memory bus. This improves bandwidth over traditional von Neumann architecture where program and data are fetched from the same memory (accesses over the same bus). Separating program and data memory further allows instructions to be sized differently than the 8-bit wide data word. PIC16C8X opcodes are 14-bits wide, enabling single word instructions. The full 14-bit wide program memory bus fetches a 14-bit instruction in a single cycle. A two-stage pipeline overlaps fetch and execution of instructions (Example 3-1). Consequently, all instructions execute in a single cycle (400 ns @ 10 MHz) except for program branches. The PIC16C83 and PIC16CR83 address 512 x 14 of program memory, and the PIC16C84, PIC16C84A, and PIC16CR84 address 1K x 14 program memory. All program memory is internal. PIC16CXX devices contain an 8-bit ALU and working register. The ALU is a general purpose arithmetic unit. It performs arithmetic and Boolean functions between data in the working register and any register file. 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), and 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 and digit borrow out bit, respectively, in subtraction. See the SUBLW and SUBWF instructions for examples. A simplified block diagram for the PIC16C8X is shown in Figure 3-1, its corresponding pin description is shown in Table 3-1. The PIC16CXX 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. 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 PIC16CXX simple yet efficient. In addition, the learning curve is reduced significantly. 1995 Microchip Technology Inc. DS30081F-page 7 Thi d t t d ith F M k 404 PIC16C8X FIGURE 3-1: PIC16C8X BLOCK DIAGRAM 13 EEPROM/ROM Program Memory PIC16C83/R83 512 x 14 PIC16C84/84A/R84 1K x 14 Data Bus 8 Program Counter 8 Level Stack (13-bit) Program Bus 14 EEPROM Data Memory RAM File Registers PIC16C83/R83/84 36 x 8 PIC16C84A/R84 68 x 8 7 EEDATA RAM Addr EEPROM Data Memory 64 x 8 EEADR Addr Mux Instruction reg 5 7 Direct Addr Indirect Addr TMR0 FSR reg RA4/T0CKI STATUS reg 8 MUX Power-up Timer Instruction Decode & Control Timing Generation Oscillator Start-up Timer I/O Ports ALU Power-on Reset Watchdog Timer RA3:RA0 W reg RB7:RB1 RB0/INT OSC2/CLKOUT OSC1/CLKIN DS30081F-page 8 MCLR VDD, VSS 1995 Microchip Technology Inc. PIC16C8X TABLE 3-1: PIC16C8X PINOUT DESCRIPTION DIP No. SOIC No. I/O/P Type OSC1/CLKIN 16 16 I OSC2/CLKOUT 15 15 O — Oscillator crystal output. Connects to crystal or resonator in crystal oscillator mode. In RC mode, OSC2 pin outputs CLKOUT which has 1/4 the frequency of OSC1, and denotes the instruction cycle rate. MCLR 4 4 I/P ST Master clear (reset) input/programming voltage input. This pin is an active low reset to the device. RA0 17 17 I/O TTL RA1 18 18 I/O TTL RA2 1 1 I/O TTL RA3 2 2 I/O TTL RA4/T0CKI 3 3 I/O ST Pin Name Buffer Type Description ST/CMOS (3) Oscillator crystal input/external clock source input. PORTA is a bi-directional I/O port. Can also be selected to be the clock input to the TMR0 timer/counter. Output is open drain type. PORTB is a bi-directional I/O port. PORTB can be software programmed for internal weak pull-up on all inputs. RB0/INT 6 6 I/O TTL/ST (1) RB1 7 7 I/O TTL RB2 8 8 I/O TTL RB0/INT can also be selected as an external interrupt pin. RB3 9 9 I/O TTL RB4 10 10 I/O TTL RB5 11 11 I/O TTL RB6 12 12 I/O TTL/ST (2) RB7 13 13 I/O TTL/ST (2) VSS 5 5 P — Ground reference for logic and I/O pins. VDD 14 14 P — Positive supply for logic and I/O pins. Interrupt on change pin. Interrupt on change pin. Interrupt on change pin. Serial programming clock. Interrupt on change pin. Serial programming data. Legend: I= input O = output I/O = Input/Output P = power — = Not used TTL = TTL input ST = Schmitt Trigger input Note 1: This buffer is a Schmitt Trigger input when configured as the external interrupt (except PIC16C84, which remains TTL). 2: This buffer is a Schmitt Trigger input when used in serial programming mode. 3: This buffer is a Schmitt Trigger input when configured in RC oscillator mode and a CMOS input otherwise. 1995 Microchip Technology Inc. DS30081F-page 9 PIC16C8X Clocking Scheme/Instruction Cycle 3.1 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, 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 (e.g., 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” 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 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 Q1 Q2 Internal phase clock Q3 Q4 PC PC OSC2/CLKOUT (RC mode) EXAMPLE 3-1: 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 1. MOVLW 55h 2. MOVWF PORTB 3. CALL SUB_1 4. BSF PORTA, BIT3 Fetch 1 Execute 1 Fetch 2 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 fetch instruction is “flushed” from the pipeline while the new instruction is being fetched and then executed. DS30081F-page 10 1995 Microchip Technology Inc. PIC16C8X 4.0 MEMORY ORGANIZATION There are two memory blocks in the PIC16C8X. These are the program memory and the data memory. Each block has its own bus, so that access to each block can occur during the same oscillator cycle. FIGURE 4-1: PROGRAM MEMORY MAP AND STACK PC<12:0> 13 CALL, RETURN RETFIE, RETLW Stack Level 1 The data memory can further be broken down into the general purpose RAM and the Special Function Registers (SFRs). The operation of the SFRs that control the “core” are described here. The SFRs used to control the peripheral modules are described in the section discussing each individual peripheral module. • • • Stack Level 8 4.1 0000h Peripheral Interrupt Vector 0004h User Memory Space The data memory area also contains the data EEPROM memory. This memory is not directly mapped into the data memory, but is indirectly mapped. That is an indirect address pointer specifies the address of the data EEPROM memory to read/write. The 64 bytes of data EEPROM memory have the address range 0h-3Fh. More details on the EEPROM memory can be found in Section 7.0. Reset Vector 1FFh (PIC16C83, PIC16CR83) Program Memory Organization The PIC16CXX has a 13-bit program counter capable of addressing an 8K x 14 program memory space. For the PIC16C83 and PIC16CR83 only the first 512 x 14 (0000h-01FFh) are physically implemented, and for the PIC16C84, PIC16C84A, and PIC16CR84 only the first 1K x 14 (0000h-03FFh) are physically implemented. Accessing a location above the physically implemented address will cause a wraparound. For example, for the PIC16C84 locations 20h, 420h, 820h, C20h, 1020h, 1420h, 1820h, and 1C20h will be the same instruction. 3FFh (PIC16C84, PIC16C84A, PIC16CR84) 1FFFh The reset vector is at 0000h and the interrupt vector is at 0004h (Figure 4-1). 1995 Microchip Technology Inc. DS30081F-page 11 Thi d t t d ith F M k 404 PIC16C8X 4.2 Data Memory Organization 4.2.2 SPECIAL FUNCTION REGISTERS The data memory is partitioned into two areas. The first is the Special Function Registers (SFR) area, while the second is the General Purpose Registers (GPR) area. The SFRs control the operation of the device. The Special Function Registers (Figure 4-2 and Table 4-1) are used by the CPU and Peripheral functions to control the device operation. These registers are static RAM. Portions of data memory are banked. This is for both the SFR area and the GPR area. The GPR area is banked to allow greater than 116 bytes of general purpose RAM. The banked areas of the SFR are for the registers that control the peripheral functions. Banking requires the use of control bits for bank selection. These control bits are located in the STATUS Register. Figure 4-2 shows the data memory map organization. The special function registers can be classified into two sets, core and peripheral. Those associated with the “core” functions are described in this section. Those related to the operation of the peripheral features are described in the section for that specific feature. Instructions MOVWF and MOVF can move values from the W register to any location in the register file (“F”), and vice-versa. The entire data memory can be accessed either directly using the absolute address of each register file or indirectly through the File Select Register (FSR) (Section 4.4). Indirect addressing uses the present value of the RP1:RP0 bits for access into the banked areas of data memory. Data memory is partitioned into two banks which contain the general purpose registers and the special function registers. Bank 0 is selected by clearing the RP0 bit (STATUS<5>). Setting the RP0 bit selects Bank 1. 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. (Figure 4-2) 4.2.1 GENERAL PURPOSE REGISTER FILE All devices have some amount of General Purpose Register (GPR) area. Each GPR is 8-bits wide and is accessed either directly, or indirectly through the FSR (Section 4.4). Architecturally, the GPR area starts at address 0Ch for bank 0 and 8Ch for bank 1. When more than 116 bytes of GPR are present on the device, banking must be performed to access the additional memory space. PIC16C8X devices have up to 68 bytes of GPR memory, and therefore do not require banking of the GPR memory. Any access to Bank 1 will cause the access to occur in Bank 0. That is, the MSb of the 8-bit direct address will be ignored. FIGURE 4-2: REGISTER FILE MAP File Address File Address 00h Indirect addr.(1) Indirect addr.(1) 01h TMR0 OPTION 81h 02h PCL PCL 82h 03h STATUS STATUS 83h 04h FSR FSR 84h 05h PORTA TRISA 85h 06h PORTB TRISB 86h 08h EEDATA EECON1 88h 09h EEADR EECON2(1) 89h 0Ah PCLATH PCLATH 8Ah 0Bh INTCON INTCON 8Bh 07h 87h 0Ch 2Fh (2) 30h (2) 80h 8Ch 36 / 68 General Purpose registers (SRAM) Mapped (accesses) in Bank 0 4Fh (2) 50h (2) AFh (2) B0h(2) CFh (2) D0h (2) FFh 7Fh Bank 0 Bank 1 Unimplemented data memory location; read as '0'. Note 1: Not a physical register. 2: The address depends on the device used. Devices with 36 bytes end at 2Fh, devices with 68 bytes end at 4Fh. DS30081F-page 12 1995 Microchip Technology Inc. PIC16C8X TABLE 4-1: Address REGISTER FILE 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 (Note3) Bank 0 00h INDF Uses contents of FSR to address data memory (not a physical register) ---- ---- ---- ---- 01h TMR0 8-bit real-time clock/counter xxxx xxxx uuuu uuuu 02h PCL Low order 8 bits of the Program Counter (PC) 0000 0000 0000 0000 (2) IRP RP1 TO RP0 PD Z DC 03h STATUS 04h FSR 05h PORTA — — — RA4/T0CKI RA3 RA2 RA1 06h PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 07h C 0001 1xxx 000q quuu xxxx xxxx uuuu uuuu RA0 ---x xxxx ---u uuuu RB0/INT xxxx xxxx uuuu uuuu Unimplemented location, read as '0' ---- ---- ---- ---uuuu uuuu Indirect data memory address pointer 0 08h EEDATA EEPROM data register xxxx xxxx 09h EEADR EEPROM address register xxxx xxxx uuuu uuuu 0Ah PCLATH — — — ---0 0000 ---0 0000 0Bh INTCON GIE EEIE T0IE 0000 000u Write buffer for upper 5 bits of the PC (1) INTE RBIE T0IF INTF RBIF 0000 000x ---- ---- ---- ---- PS1 PS0 1111 1111 1111 1111 0000 0000 0000 0000 0001 1xxx 000q quuu Bank 1 80h INDF 81h OPTION 82h PCL 83h STATUS (2) 84h FSR 85h TRISA 86h TRISB 87h 88h EECON1 Uses contents of FSR to address data memory (not a physical register) RBPU INTEDG T0CS T0SE PSA PS2 Low order 8 bits of Program Counter (PC) IRP RP1 RP0 TO PD Z DC C Indirect data memory address pointer 0 — — — PORTA data direction register xxxx xxxx uuuu uuuu ---1 1111 ---1 1111 PORTB data direction register 1111 1111 1111 1111 Unimplemented location, read as '0' ---- ---- ---- ---- ---0 x000 ---0 q000 — — — 89h EECON2 0Ah PCLATH — — — 0Bh INTCON GIE EEIE T0IE EEIF WRERR WREN WR RD EEPROM control register 2 (not a physical register) 1995 Microchip Technology Inc. Write buffer for upper 5 bits of the PC (1) INTE RBIE T0IF INTF ---- ---- ---- ---- ---0 0000 ---0 0000 RBIF DS30081F-page 13 PIC16C8X 4.2.2.1 STATUS REGISTER The STATUS register contains the arithmetic status of the ALU, the RESET status and the bank select bit for data memory. As with any register, the STATUS register can be the destination for any instruction. 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 device logic. Furthermore, the TO and PD bits are not writable. Therefore, the result of an instruction with the STATUS register as destination may be different than intended. For example, CLRF STATUS will clear the upper-three bits and set the Z bit. This leaves the STATUS register as 000u u1uu (where u = unchanged). DS30081F-page 14 Only the BCF, BSF, SWAPF and MOVWF instructions should be used to alter the STATUS register (Table 9-2) because these instructions do not affect any status bit. Note 1: The IRP and RP1 bits (STATUS<7:6>) are not used by the PIC16C8X and should be programmed as cleared. Use of these bits as general purpose R/W bits is NOT recommended, since this may affect upward compatibility with future products. Note 2: The C and DC bits operate as a borrow and digit borrow out bit, respectively, in subtraction. See the SUBLW and SUBWF instructions for examples. Note 3: When 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. The specified bit(s) will be updated according to device logic. 1995 Microchip Technology Inc. PIC16C8X FIGURE 4-3: R/W-0 IRP STATUS REGISTER (ADDRESS 03h, 83h) R/W-0 RP1 R/W-0 RP0 R-1 R-1 TO PD R/W-x Z R/W-x DC bit7 bit 7: R/W-x C 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) 0 = Bank 0, 1 (00h - FFh) 1 = Bank 2, 3 (100h - 1FFh) The IRP bit is not used by the PIC16C8X. IRP should be maintained clear. bit 6-5: RP1:RP0: Register Bank Select bits (used for direct addressing) 00 = Bank 0 (00h - 7Fh) 01 = Bank 1 (80h - FFh) 10 = Bank 2 (100h - 17Fh) 11 = Bank 3 (180h - 1FFh) Each bank is 128 bytes. Only bit RP0 is used by the PIC16C8X. RP1 should be maintained 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 (for ADDWF and ADDLW 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 (for ADDWF and ADDLW 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. 1995 Microchip Technology Inc. DS30081F-page 15 PIC16C8X 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 PORTB. FIGURE 4-4: R/W-1 RBPU bit7 When the prescaler is assigned to the WDT (PSA = '1'), TMR0 has a 1:1 prescaler assignment. OPTION REGISTER (ADDRESS 81h) R/W-1 INTEDG R/W-1 T0CS R/W-1 T0SE R/W-1 PSA R/W-1 PS2 R/W-1 PS1 R/W-1 PS0 bit0 bit 7: RBPU: PORTB Pull-up Enable bit 1 = PORTB pull-ups are disabled 0 = PORTB pull-ups are enabled (by individual port latch values) bit 6: INTEDG: Interrupt Edge Select bit 1 = Interrupt on rising edge of RB0/INT pin 0 = Interrupt on falling edge of RB0/INT pin bit 5: T0CS: TMR0 Clock Source Select bit 1 = Transition on RA4/T0CKI pin 0 = Internal instruction cycle clock (CLKOUT) bit 4: T0SE: TMR0 Source Edge Select bit 1 = Increment on high-to-low transition on RA4/T0CKI pin 0 = Increment on low-to-high transition on RA4/T0CKI pin bit 3: PSA: Prescaler Assignment bit 1 = Prescaler assigned to the WDT 0 = Prescaler assigned to TMR0 R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR reset bit 2-0: PS2:PS0: Prescaler Rate Select bits Bit Value TMR0 Rate WDT Rate 000 001 010 011 100 101 110 111 1:2 1:4 1:8 1 : 16 1 : 32 1 : 64 1 : 128 1 : 256 1:1 1:2 1:4 1:8 1 : 16 1 : 32 1 : 64 1 : 128 DS30081F-page 16 1995 Microchip Technology Inc. PIC16C8X 4.2.2.3 INTCON REGISTER Note: The INTCON register is a readable and writable register which contains the various enable bits for all interrupt sources. FIGURE 4-5: R/W-0 GIE bit7 bit 7: 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 EEIE R/W-0 T0IE R/W-0 INTE R/W-0 RBIE R/W-0 T0IF R/W-0 INTF R/W-x RBIF bit0 R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’ - n = Value at POR reset GIE: Global Interrupt Enable bit 1 = Enables all un-masked interrupts 0 = Disables all interrupts Note: For the operation of the interrupt structure, please refer to Section 8.5. bit 6: EEIE: EE Write Complete Interrupt Enable bit 1 = Enables the EE write complete interrupt 0 = Disables the EE write complete interrupt bit 5: T0IE: TMR0 Overflow Interrupt Enable bit 1 = Enables the TMR0 interrupt 0 = Disables the TMR0 interrupt bit 4: INTE: RB0/INT Interrupt Enable bit 1 = Enables the RB0/INT interrupt 0 = Disables the RB0/INT interrupt bit 3: RBIE: RB Port Change Interrupt Enable bit 1 = Enables the RB port change interrupt 0 = Disables the RB port change interrupt bit 2: T0IF: TMR0 overflow interrupt flag bit 1 = TMR0 has overflowed (must be cleared in software) 0 = TMR0 did not overflow bit 1: INTF: RB0/INT Interrupt Flag bit 1 = The RB0/INT interrupt occurred 0 = The RB0/INT interrupt did not occur bit 0: RBIF: RB Port Change Interrupt Flag bit 1 = When at least one of the RB7:RB4 pins changed state (must be cleared in software) 0 = None of the RB7:RB4 pins have changed state 1995 Microchip Technology Inc. DS30081F-page 17 PIC16C8X 4.3 PCL and PCLATH 4.3.2 The Program Counter (PC) is 13-bits wide. The low byte is the PCL register, which is a readable and writable register. The high byte of the PC (PC<12:8>) is not directly readable nor writable and comes from the PCLATH register. The PCLATH (PC latch high) register is a holding register for PC<12:8>. The contents of PCLATH are transferred to the upper byte of the program counter when the PC is loaded with a new value. This occurs during a CALL, GOTO or a write to PCL. The high bits of PC are loaded from PCLATH as shown in Figure 4-6. FIGURE 4-6: LOADING OF PC IN DIFFERENT SITUATIONS PCH 12 8 7 0 INST with PCL as dest 8 PCLATH<4:0> 5 ALU result PCLATH PCH 12 11 10 PCL 8 7 0 PC GOTO, CALL 2 PCLATH<4:3> 11 Opcode <10:0> PCLATH 4.3.1 The PIC16CXX has an 8 deep x 13-bit wide hardware stack (Figure 4-1). The stack space is not part of either program or data space and the stack pointer is not readable or writable. The entire 13-bit PC is PUSH'ed onto the stack when a CALL instruction is executed or an interrupt is acknowledged. The stack is POP'ed in the event of a RETURN, RETLW or a RETFIE instruction execution. PCLATH is not affected by a PUSH or a POP operation. The stack operates as a circular buffer. That is, after the stack has been PUSH'ed 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). If the stack is effectively POP'ed nine times, the PC value is the same as the value from the first POP. PCL PC COMPUTED GOTO 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). Note 1: There are no status bits to indicate stack overflow or stack underflow conditions. Note 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 4.3.3 PROGRAM MEMORY PAGING The PIC16C83 and PIC16CR83 have 512 words of program memory. The PIC16C84, PIC16C84A, and PIC16CR84 have 1K of program memory. The CALL and GOTO instructions have an 11-bit address range. This 11-bit address range allows a branch within a 2K program memory page size. For future PIC16C8X program memory expansion, there must be another two bits to specify the program memory page. These paging bits come from the PCLATH<4:3> bits (Figure 4-6). When doing a CALL or a GOTO instruction, the user must ensure that these page bits (PCLATH<4:3>) are programmed to the desired program memory page. If a CALL instruction (or interrupt) is executed, the entire 13-bit PC is pushed onto the stack. Therefore, manipulation of the PCLATH<4:3> is not required for the return instructions (which POPs the PC from the stack). Note: DS30081F-page 18 STACK The PIC16C8X ignores the PCLATH<4:3> bits, which are used for program memory pages 1, 2 and 3 (0800h - 1FFFh). The use of PCLATH<4:3> as general purpose R/W bits is not recommended since this may affect upward compatibility with future products. 1995 Microchip Technology Inc. PIC16C8X 4.4 Indirect Addressing, INDF and FSR Registers EXAMPLE 4-1: The INDF register is not a physical register and is used in conjunction with the FSR register to perform indirect addressing. Indirect addressing is possible by using the INDF register. Any instruction using the INDF register actually accesses data pointed to by the file select register (FSR). Reading INDF itself indirectly (FSR = 0) will produce 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 4-7. However, IRP is not used in the PIC16C8X. INDIRECT ADDRESSING movlw movwf clrf incf btfss goto NEXT 0x20 FSR INDF FSR 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 4-7: DIRECT/INDIRECT ADDRESSING Indirect Addressing Direct Addressing RP1 RP0 bank select 6 from opcode 0 IRP location select 7 bank select 00 01 10 (FSR) 0 location select 11 00h 00h 0Bh 0Ch not used 2Fh (1) 30h (1) mapped in bank 0 4Fh (2) 50h (2) 7Fh 7Fh Bank 0 Bank 1 Bank 2 Bank 3 Note 1: PIC16C83, PIC16CR83, and PIC16C84 devices. 2: PIC16C84A and PIC16CR84 devices 3: For memory map detail see Figure 4-1. 1995 Microchip Technology Inc. DS30081F-page 19 PIC16C8X NOTES: DS30081F-page 20 1995 Microchip Technology Inc. PIC16C8X 5.0 I/O PORTS EXAMPLE 5-1: The PIC16C8X family has two ports, PORTA and PORTB. Some port pins are multiplexed with an alternate function for other features on the device. 5.1 PORTA and TRISA Registers PORTA is a 5-bit wide latch. RA4 is a Schmitt Trigger input and an open drain output. All other RA port pins have TTL input levels and full CMOS output drivers. All pins have data direction bits (TRIS registers) which can configure these pins as output or input. A '1' on any bit in the TRISA register puts the corresponding output driver in a hi-impedance mode. A '0' on any bit in the TRISA register puts the contents of the output latch on the selected pin(s). CLRF PORTA BSF MOVLW STATUS, RP0 0x0F MOVWF TRISA FIGURE 5-2: WR PORT WR Port D D Q CK Q N RA4 pin VSS WR TRIS BLOCK DIAGRAM OF PINS RA3:RA0 D Q CK Q Schmitt Trigger input buffer TRIS Latch Q VDD CK Initialize PORTA by setting output data latches Select Bank 1 Value used to initialize data direction Set RA<3:0> as inputs RA4 as outputs TRISA<7:5> are always read as '0'. Data Latch The RA4 pin is multiplexed with the TMR0 clock input. Data bus ; ; ; ; ; ; ; ; ; ; ; BLOCK DIAGRAM OF PIN RA4 Data bus Reading the PORTA register reads the status of the pins whereas writing to it will write to the port latch. All write operations are read-modify-write operations. So a write to a port implies that the port pins are first read, then this value is modified and written to the port data latch. FIGURE 5-1: INITIALIZING PORTA Q RD TRIS P Q D Data Latch N D WR TRIS EN EN I/O pin RD PORT Q VSS CK TMR0 clock input Q Note: I/O pin has protection diodes to VSS only. TRIS Latch TTL input buffer Note: RD TRIS Q D EN RD PORT For the PIC16C84 Only: For crystal oscillator configurations operating below 500 kHz, the device may generate a spurious internal Q-clock when PORTA<0> switches state. This does not occur with an external clock in RC mode. To avoid this, the RA0 pin should be kept static, i.e. in input/output mode, pin RA0 should not be toggled. Note: I/O pins have protection diodes to VDD and VSS. 1995 Microchip Technology Inc. DS30081F-page 21 Thi d t t d ith F M k 404 PIC16C8X TABLE 5-1: PORTA FUNCTIONS Name Bit0 Buffer Type RA0 RA1 RA2 RA3 RA4/T0CKI bit0 bit1 bit2 bit3 bit4 TTL TTL TTL TTL ST Function Input/output Input/output Input/output Input/output Input/output or external clock input for TMR0. Output is open drain type. Legend: TTL = TTL input, ST = Schmitt Trigger input TABLE 5-2: Address SUMMARY OF REGISTERS ASSOCIATED WITH PORTA Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 05h PORTA — — — RA4/T0CKI RA3 RA2 85h TRISA — — — TRISA4 TRISA3 TRISA2 Bit 0 Value on Power-on Reset Value on all other resets RA1 RA0 ---x xxxx ---u uuuu TRISA1 TRISA0 ---1 1111 ---1 1111 Bit 1 Legend: x = unknown, u = unchanged, - = unimplemented read as '0'. Shaded cells are unimplemented, read as '0' DS30081F-page 22 1995 Microchip Technology Inc. PIC16C8X PORTB and TRISB Registers 5.2 PORTB is an 8-bit wide bi-directional port. The corresponding data direction register is TRISB. A '1' on any bit in the TRISB register puts the corresponding output driver in a hi-impedance mode. A '0' on any bit in the TRISB register puts the contents of the output latch on the selected pin(s). Each of the PORTB pins have a weak internal pull-up. A single control bit can turn on all the pull-ups. This is done by clearing the RBPU (OPTION<7>) bit. The weak pull-up is automatically turned off when the port pin is configured as an output. The pull-ups are disabled on a Power-on Reset. Four of PORTB’s pins, RB7:RB4, have an interrupt on change feature. Only pins configured as inputs can cause this interrupt to occur (i.e., any RB7:RB4 pin configured as an output is excluded from the interrupt on change comparison). The pins value in input mode are compared with the old value latched on the last read of PORTB. The “mismatch” outputs of the pins are OR’ed together to generate the RB port change interrupt. FIGURE 5-3: BLOCK DIAGRAM OF PINS RB7:RB4 VDD RBPU Data bus weak P pull-up Data Latch D This interrupt can wake the device from SLEEP. The user, in the interrupt service routine, can clear the interrupt in the following manner: a) b) Read (or write) PORTB. This will end the mismatch condition. Clear flag bit RBIF. A mismatch condition will continue to set the RBIF bit. Reading PORTB will end the mismatch condition, and allow the RBIF bit to be cleared. This interrupt on mismatch feature, together with software configurable pull-ups on these four pins allow easy interface to a key pad and make it possible for wake-up on key-depression (see AN552 in the Embedded Control Handbook). Note 1: For the PIC16C84 Only; If a change on the I/O pin should occur when a read operation of PORTB is being executed (start of the Q2 cycle), the RBIF interrupt flag bit may not be set. Note 2: For all other PIC16C8X devices; For a change on the I/O pin to be recognized, the pulse width must be at least TCY wide. The interrupt on change feature is recommended for wake-up on key depression operation and operations where PORTB is only used for the interrupt on change feature. Polling of PORTB is not recommended while using the interrupt on change feature. FIGURE 5-4: Q I/O pin WR Port BLOCK DIAGRAM OF PINS RB3:RB0 (PIC16C84 ONLY) CK VDD RBPU TRIS Latch D weak P pull-up Q Data bus WR TRIS TTL Input Buffer CK WR Port Q RD Port D Q I/O pin CK TRIS Latch D Q Latch RD TRIS Data Latch D WR TRIS Input Buffer CK EN Set RBIF From other RB7:RB4 pins RD TRIS Q D Q EN RD Port Note 1: TRISB = '1' enables weak pull-up (if RBPU = '0' in the OPTION register). 2: I/O pins have diode protection to VDD and VSS. RD Port D EN RB0/INT(3) RD Port Note 1: TRISB = '1' enables weak pull-up (if RBPU = '0' in the OPTION register). 2: I/O pins have diode protection to VDD and VSS. 1995 Microchip Technology Inc. DS30081F-page 23 PIC16C8X FIGURE 5-5: BLOCK DIAGRAM OF PINS RB3:RB0 (ALL OTHER PIC16C8X DEVICES) EXAMPLE 5-2: INITIALIZING PORTB CLRF PORTB BSF MOVLW STATUS, RP0 0xCF MOVWF TRISB VDD RBPU(2) weak P pull-up Data Latch D Q Data bus WR Port I/O pin(1) CK TRIS Latch D Q WR TRIS ; ; ; ; ; ; ; ; ; ; Initialize PORTB by setting output data latches Select Bank 1 Value used to initialize data direction Set RB<3:0> as inputs RB<5:4> as outputs RB<7:6> as inputs TTL Input Buffer CK RD TRIS Q D EN RD Port RB0/INT Schmitt Trigger Buffer RD Port Note 1: I/O pins have diode protection to VDD and VSS. 2: TRISB = '1' enables weak pull-up if RBPU = '0' (OPTION<7>). TABLE 5-3: Name RB0/INT PORTB FUNCTIONS Bit Buffer Type bit0 TTL/ST(1) I/O Consistency Function Input/output pin or external interrupt input. Internal software programmable weak pull-up. RB1 bit1 TTL Input/output pin. Internal software programmable weak pull-up. RB2 bit2 TTL Input/output pin. Internal software programmable weak pull-up. RB3 bit3 TTL Input/output pin. Internal software programmable weak pull-up. RB4 bit4 TTL Input/output pin (with interrupt on change). Internal software programmable weak pull-up. RB5 bit5 TTL Input/output pin (with interrupt on change). Internal software programmable weak pull-up. RB6 bit6 TTL/ST(2) Input/output pin (with interrupt on change). Internal software programmable weak pull-up. Serial programming clock. RB7 bit7 TTL/ST(2) Input/output pin (with interrupt on change). Internal software programmable weak pull-up. Serial programming data. Legend: TTL = TTL input, ST = Schmitt Trigger. Note 1: This buffer is a Schmitt Trigger input when configured as the external interrupt, except for the PIC16C84, which remains TTL. 2: This buffer is a Schmitt Trigger input when used in serial programming mode. TABLE 5-4: Address SUMMARY OF REGISTERS ASSOCIATED WITH PORTB 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 06h PORTB RB7 RB6 RB5 RB4 RB3 RB2 RB1 RB0/INT xxxx xxxx uuuu uuuu 86h TRISB TRISB7 TRISB6 TRISB5 TRISB4 TRISB3 TRISB2 TRISB1 TRISB0 1111 1111 1111 1111 81h OPTION RBPU INTEDG T0CS T0SE PSA PS2 PS1 PS0 1111 1111 1111 1111 Legend: x = unknown, u = unchanged. Shaded cells are not used by PORTB. DS30081F-page 24 1995 Microchip Technology Inc. PIC16C8X 5.3 I/O Programming Considerations 5.3.2 5.3.1 BI-DIRECTIONAL I/O PORTS The actual write to an I/O port happens at the end of an instruction cycle, whereas for reading, the data must be valid at the beginning of the instruction cycle (Figure 5-6). Therefore, care must be exercised if a write followed by a read operation is carried out on the same I/O port. The sequence of instructions should be such that the pin voltage stabilizes (load dependent) before the next instruction which causes that file to be read into the CPU is executed. Otherwise, the previous state of that pin may be read into the CPU rather than the new state. When in doubt, it is better to separate these instructions with a NOP or another instruction not accessing this I/O port. 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 PORTB will cause all eight bits of PORTB to be read into the CPU. Then the BSF operation takes place on bit5 and PORTB is written to the output latches. If another bit of PORTB is used as a bi-directional I/O pin (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 into output mode later on, the content of the data latch is 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. 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 current may damage the chip. FIGURE 5-6: SUCCESSIVE OPERATIONS ON I/O PORTS Example 5-3 shows the effect of two sequential readmodify-write instructions (e.g., BCF, BSF, etc.) on an I/O port. EXAMPLE 5-3: ;Initial PORT settings: PORTB<7:4> Inputs ; PORTB<3:0> Outputs ;PORTB<7:6> have external pull-ups and are ;not connected to other circuitry ; ; PORT latch PORT pins ; ---------- --------BCF PORTB, 7 ; 01pp ppp 11pp ppp BCF PORTB, 6 ; 10pp ppp 11pp ppp BSF STATUS, RP0 ; BCF TRISB, 7 ; 10pp ppp 11pp ppp BCF TRISB, 6 ; 10pp ppp 10pp ppp ; ;Note that the user may have expected the ;pin values to be 00pp ppp. The 2nd BCF ;caused RB7 to be latched as the pin value ;(high). SUCCESSIVE I/O OPERATION Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 PC Instruction fetched MOVWF PORTB write to PORTB PC + 1 PC + 2 PC + 3 NOP NOP MOVF PORTB,W Port pin sampled here MOVWF PORTB write to PORTB 1995 Microchip Technology Inc. This example shows as write to PORTB followed by a read from PORTB. Therefore, at higher clock frequencies, a write followed by a read may be problematic. MOVF PORTB,W NOP Note: Note that: data setup time = (0.25 TCY - TPD) where:TCY = instruction cycle TPD = propagation delay RB7:RB0 Instruction executed READ-MODIFY-WRITE INSTRUCTIONS ON AN I/O PORT NOP DS30081F-page 25 PIC16C8X NOTES: DS30081F-page 26 1995 Microchip Technology Inc. PIC16C8X 6.0 TIMER0 MODULE AND TMR0 REGISTER edge select bit, T0SE (OPTION<4>). Clearing bit T0SE selects the rising edge. Restrictions on the external clock input are discussed in detail in Section 6.2. The Timer0 module timer/counter has the following features: • • • • • • The prescaler is 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 (Section 6.3) is assigned to the Timer0 Module, the prescale value (1:2, 1:4, ..., 1:256) is software selectable. 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 The TMR0 interrupt is generated when the TMR0 register overflows from FFh to 00h. This overflow sets the T0IF bit (INTCON<2>). The interrupt can be masked by clearing enable bit T0IE (INTCON<5>). The T0IF bit must be cleared in software by the Timer0 Module interrupt service routine before re-enabling this interrupt. The TMR0 interrupt (Figure 6-4) cannot wake the processor from SLEEP since the timer is shut off during SLEEP. Counter mode is selected by setting the T0CS bit (OPTION<5>). In this mode TMR0 will increment either on every rising or falling edge of pin RA4/T0CKI. The incrementing edge is determined by the T0 source FIGURE 6-1: TMR0 Interrupt 6.1 Timer mode is selected by clearing the T0CS bit (OPTION<5>). In timer mode, the Timer0 module (Figure 6-1) will increment every instruction cycle (without prescaler). If the TMR0 register is written, the increment is inhibited for the following two cycles (Figure 6-2 and Figure 6-3). The user can work around this by writing an adjusted value to the TMR0 register. TMR0 BLOCK DIAGRAM Data bus FOSC/4 0 PSout 1 Sync with Internal clocks 1 RA4/T0CKI pin Programmable Prescaler 8 0 TMR0 register PSout (2 cycle delay) T0SE 3 PS2, PS1, PS0 Set bit T0IF on Overflow PSA T0CS Note 1: Bits T0CS, T0SE, PS2, PS1, PS0 and PSA are located in the OPTION register. 2: The prescaler is shared with the Watchdog Timer (Figure 6-6) FIGURE 6-2: TMR0 TIMING: INTERNAL CLOCK/NO PRESCALER 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 PC Instruction Fetch TMR0 T0 PC PC+1 PC+2 MOVWF TMR0 MOVF TMR0,W MOVF TMR0,W T0+1 Instruction Executed PC+3 MOVF TMR0,W T0+2 NT0 NT0 Write TMR0 executed Read TMR0 reads NT0 Read TMR0 reads NT0 PC+4 MOVF TMR0,W NT0 Read TMR0 reads NT0 1995 Microchip Technology Inc. PC+5 PC+6 MOVF TMR0,W NT0+1 NT0+2 Read TMR0 reads NT0 + 1 T0 Read TMR0 reads NT0 + 2 DS30081F-page 27 Thi d t t d ith F M k 404 PIC16C8X FIGURE 6-3: TMR0 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-1 PC Instruction Fetch PC PC+1 PC+2 MOVWF TMR0 MOVF TMR0,W MOVF TMR0,W T0+1 T0 TMR0 Instruction Execute PC+4 PC+5 MOVF TMR0,W PC+6 MOVF TMR0,W NT0+1 NT0 Write TMR0 executed FIGURE 6-4: PC+3 MOVF TMR0,W Read TMR0 reads NT0 Read TMR0 reads NT0 Read TMR0 reads NT0 Read TMR0 reads NT0 Read TMR0 reads NT0 + 1 TMR0 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) TMR0 timer FEh T0IF bit 4 (INTCON<2>) 1 FFh 00h 01h 02h 1 GIE bit (INTCON<7>) Interrupt Latency(2) INSTRUCTION FLOW PC PC Instruction fetched Inst (PC) Instruction executed Inst (PC-1) PC +1 PC +1 Inst (PC+1) Inst (PC) Dummy cycle 0004h 0005h Inst (0004h) Inst (0005h) Dummy cycle Inst (0004h) Note 1: T0IF interrupt flag is sampled here (every Q1). 2: Interrupt latency = 3.25Tcy, where Tcy = instruction cycle time. 3: CLKOUT is available only in RC oscillator mode. 4: The timer clock (after the synchronizer circuit) which increments the timer from FFh to 00h immediately sets the T0IF bit. The TMR0 register will roll over 3 Tosc cycles later. DS30081F-page 28 1995 Microchip Technology Inc. PIC16C8X 6.2 Using TMR0 with External Clock 6.3 When an external clock input is used for TMR0, it must meet certain requirements. The external clock requirement is due to internal phase clock (TOSC) synchronization. Also, there is a delay in the actual incrementing of the TMR0 register after synchronization. 6.2.1 Prescaler An 8-bit counter is available as a prescaler for the Timer0 Module, or as a postscaler for the Watchdog Timer (Figure 6-6). 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 exclusive 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. EXTERNAL CLOCK SYNCHRONIZATION When no prescaler is used, the external clock input is the same as the prescaler output. The synchronization of pin RA4/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 6-5). Therefore, it is necessary for T0CKI to be high for at least 2Tosc (plus a small RC delay) and low for at least 2Tosc (plus a small RC delay). Refer to the electrical specification of the desired device. The PSA and PS2:PS0 bits (OPTION<3:0>) determine the prescaler assignment and prescale ratio. When assigned to the Timer0 Module, all instructions writing to the Timer0 Module (e.g., 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. When a prescaler is used, the external clock input is divided by an asynchronous ripple counter type prescaler 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 (plus a small RC delay) 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 AC Electrical Specifications of the desired device. 6.2.2 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 6-5 shows the delay from the external clock edge to the timer incrementing. FIGURE 6-5: TIMER0 TIMING WITH EXTERNAL CLOCK Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Ext. Clock Input or Prescaler Out (Note 2) (Note 3) Ext. Clock/Prescaler Output After Sampling Increment TMR0 (Q4) TMR0 T0 T0 + 1 T0 + 2 Note 1: Delay from clock input change to TMR0 increment is 3Tosc to 7Tosc. (Duration of Q = Tosc). Therefore, the error in measuring the interval between two edges on TMR0 input = ± 4Tosc max. 2: External clock if no prescaler selected, Prescaler output otherwise. 3: The arrows ↑ indicate where sampling occurs. A small clock pulse may be missed by sampling. 1995 Microchip Technology Inc. DS30081F-page 29 PIC16C8X FIGURE 6-6: BLOCK DIAGRAM OF THE TMR0/WDT PRESCALER Data Bus CLKOUT (= Fosc/4) 0 RA4/T0CKI pin M U X 8 1 M U X 0 1 SYNC 2 Cycles TMR0 register T0SE T0CS 0 Watchdog Timer 1 M U X Set bit T0IF on overflow PSA 8-bit Prescaler 8 8 - to - 1MUX PS2:PS0 PSA WDT Enable bit 1 0 MUX PSA WDT time-out Note: T0CS, T0SE, PSA, PS2:PS0 are bits in the OPTION register. DS30081F-page 30 1995 Microchip Technology Inc. PIC16C8X 6.3.1 SWITCHING PRESCALER ASSIGNMENT EXAMPLE 6-2: The prescaler assignment is fully under software control (i.e., it can be changed “on the fly” during program execution). Note: STATUS, RP0 TMR0 BSF CLRWDT MOVLW MOVWF BCF STATUS, RP0 b'xxxx1xxx' OPTION STATUS, RP0 TABLE 6-1: Name BSF MOVLW STATUS, RP0 b'xxxx0xxx' MOVWF BCF OPTION STATUS, RP0 ;Clear WDT and ; prescaler ;Bank 1 ;Select TMR0, new ; prescale value ’ and clock source ; ;Bank 0 CHANGING PRESCALER (TIMER0→WDT) BCF CLRF Address CLRWDT To avoid an unintended device RESET, the following instruction sequence (Example 6-1) must be executed when changing the prescaler assignment from Timer0 to the WDT. This sequence must be taken even if the WDT is disabled. To change prescaler from the WDT to the Timer0 module use the sequence shown in Example 6-2. EXAMPLE 6-1: CHANGING PRESCALER (WDT→TIMER0) ;Bank 0 ;Clear TMR0 ; and Prescaler ;Bank 1 ;Clears WDT ;Select new ; prescale value ;Bank 0 REGISTERS ASSOCIATED WITH TIMER0 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 INTE RBIE T0IF INTF RBIF Timer0 module’s register Value on Power-on Reset Value on all other resets xxxx xxxx uuuu uuuu 0000 000x 0000 0000 01h TMR0 0Bh INTCON GIE EEIE T0IE 81h OPTION RBPU INTEDG T0CS T0SE PSA PS2 PS1 PS0 1111 1111 1111 1111 85h TRISA — — — TRISA4 TRISA3 TRISA2 TRISA1 TRISA0 ---1 1111 ---1 1111 Legend: x = unknown, u = unchanged. - = unimplemented read as '0'. Shaded cells are not associated with Timer0. 1995 Microchip Technology Inc. DS30081F-page 31 PIC16C8X NOTES: DS30081F-page 32 1995 Microchip Technology Inc. PIC16C8X 7.0 DATA EEPROM MEMORY When the device is code protected, the CPU may continue to read and write the data EEPROM memory. The device programmer can no longer access this memory. The EEPROM data memory is readable and writable during normal operation (full VDD range). This memory is not directly mapped in the register file space. Instead it is indirectly addressed through the Special Function Registers. There are four SFRs used to read and write this memory. These registers are: • • • • 7.1 EEADR The EEADR register can address up to a maximum of 256 bytes of data EEPROM. Only the first 64 bytes of data EEPROM are implemented and only six of the eight bits in the register (EEADR<5:0>) are required. EECON1 EECON2 EEDATA EEADR The upper two bits are address decoded. This means that these two bits should always be '0' to ensure that the address is in the 64 byte memory space. EEDATA holds the 8-bit data for read/write, and EEADR holds the address of the EEPROM location being accessed. PIC16C8X devices have 64 bytes of data EEPROM with an address range from 0h to 3Fh. The EEPROM data memory allows byte read and write. A byte write automatically erases the location and writes the new data (erase before write). The EEPROM data memory is rated for high erase/write cycles. The write time is controlled by an on-chip timer. The write-time will vary with voltage and temperature as well as from chip to chip. Please refer to AC specifications for exact limits. FIGURE 7-1: EECON1 REGISTER (ADDRESS 88h) U U U R/W-0 R/W-x R/W-0 R/S-0 R/S-x — — — EEIF WRERR WREN WR RD bit7 bit0 R W S U = Readable bit = Writable bit = Settable bit = Unimplemented bit, read as ‘0’ - n = Value at POR reset bit 7:5 Unimplemented: Read as '0' bit 4 EEIF: EEPROM Write Operation Interrupt Flag bit 1 = The write operation completed (must be cleared in software) 0 = The write operation is not complete or has not been started bit 3 WRERR: EEPROM Error Flag bit 1 = A write operation is prematurely terminated (any MCLR reset or any WDT reset during normal operation) 0 = The write operation completed bit 2 WREN: EEPROM Write Enable bit 1 = Allows write cycles 0 = Inhibits write to the data EEPROM bit 1 WR: Write Control bit 1 = initiates a write cycle. (The bit is cleared by hardware once write is complete. The WR bit can only be set (not cleared) in software. 0 = Write cycle to the data EEPROM is complete bit 0 RD: Read Control bit 1 = Initiates an EEPROM read (read takes one cycle. RD is cleared in hardware. The RD bit can only be set (not cleared) in software). 0 = Does not initiate an EEPROM read 1995 Microchip Technology Inc. DS30081F-page 33 Thi d t t d ith F M k 404 PIC16C8X EECON1 and EECON2 Registers EECON1 is the control register with five low order bits physically implemented. The upper-three bits are non-existent and read as '0's. Control bits RD and WR initiate read and write, respectively. These bits cannot be cleared, only set, in software. They are cleared in hardware at completion of the read or write operation. The inability to clear the WR bit in software prevents the accidental, premature termination of a write operation. The WREN bit, when set, will allow a write operation. On power-up, the WREN bit is clear. The WRERR bit is set when a write operation is interrupted by a MCLR reset or a WDT time-out reset during normal operation. In these situations, following reset, the user can check the WRERR bit and rewrite the location. The data and address will be unchanged in the EEDATA and EEADR registers. Interrupt flag bit EEIF is set when write is complete. It must be cleared in software. EECON2 is not a physical register. Reading EECON2 will read all '0's. The EECON2 register is used exclusively in the Data EEPROM write sequence. 7.3 Reading the EEPROM Data Memory To read a data memory location, the user must write the address to the EEADR register and then set control bit RD (EECON1<0>). The data is available, in the very next cycle, in the EEDATA register; therefore it can be read in the next instruction. EEDATA will hold this value until another read or until it is written to by the user (during a write operation). EXAMPLE 7-1: BCF MOVLW MOVWF BSF BSF BCF MOVF DATA EEPROM READ STATUS, RP0 CONFIG_ADDR EEADR STATUS, RP0 EECON1, RD STATUS, RP0 EEDATA, W DS30081F-page 34 ; ; ; ; ; ; ; Bank 0 Address to read Bank 1 EE Read Bank 0 W = EEDATA 7.4 Writing to the EEPROM Data Memory To write an EEPROM data location, the user must first write the address to the EEADR register and the data to the EEDATA register. Then the user must follow a specific sequence to initiate the write for each byte. EXAMPLE 7-2: Required Sequence 7.2 DATA EEPROM WRITE BSF BCF MOVLW MOVWF MOVLW MOVWF BSF STATUS, RP0 INTCON, GIE 55h EECON2 AAh EECON2 EECON1,WR BSF INTCON, GIE ; ; ; ; ; ; ; ; ; Bank 1 Disable INTs. Write 55h Write AAh Set WR bit begin write Enable INTs. The write will not initiate if the above sequence is not exactly followed (write 55h to EECON2, write AAh to EECON2, then set WR bit) for each byte. We strongly recommend that interrupts be disabled during this code segment. Additionally, the WREN bit in EECON1 must be set to enable write. This mechanism prevents accidental writes to data EEPROM due to errant (unexpected) code execution (i.e., lost programs). The user should keep the WREN bit clear at all times, except when updating EEPROM. The WREN bit is not cleared by hardware After a write sequence has been initiated, clearing the WREN bit will not affect this write cycle. The WR bit will be inhibited from being set unless the WREN bit is set. At the completion of the write cycle, the WR bit is cleared in hardware and the EE Write Complete Interrupt Flag bit (EEIF) is set. The user can either enable this interrupt or poll this bit. EEIF must be cleared by software. Note: For the PIC16C84 Only; The data EEPROM memory E/W cycle time may occasionally exceed the 10 ms specification (typical). To ensure that the write cycle is complete, use the EE interrupt or poll the WR bit (EECON1<1>). Both these events signify the completion of the write cycle. 1995 Microchip Technology Inc. PIC16C8X Write Verify 7.5 7.6 Depending on the application, good programming practice may dictate that the value written to the Data EEPROM should be verified (Example 7-3) to the desired value to be written. This should be used in applications where an EEPROM bit will be stressed near the specification limit. The Total Endurance disk will help determine your comfort level. There are conditions when the device may not want to write to the data EEPROM memory. To protect against spurious EEPROM writes, various mechanisms have been built in. On power-up, WREN is cleared. Also, the Power-up Timer (72 ms duration) prevents EEPROM write. The write initiate sequence and the WREN bit together help prevent an accidental write during brown-out, power glitch, or software malfunction. Generally the EEPROM write failure will be a bit which was written as a '1', but reads back as a '0' (due to leakage off the bit). EXAMPLE 7-3: BCF : : MOVF BSF 7.7 WRITE VERIFY STATUS, RP0 ; ; ; EEDATA, W ; STATUS, RP0 ; Must be in Bank 0 Bank 1 For ROM devices, there are two code protection bits (Section 8.9). One for the ROM program memory and one for the Data EEPROM memory. EECON1, RD ; YES, Read the ; value written STATUS, RP0 ; Bank 0 7.8 BCF ; ; Is the value written (in W reg) and ; read (in EEDATA) the same? ; SUBWF EEDATA, W ; BTFSS STATUS, Z ; Is difference 0? GOTO WRITE_ERR ; NO, Write error : ; YES, Good write : ; Continue program TABLE 7-1: Address Data EEPROM Operation during Code Protect When the device is code protected, the CPU is able to read and write unscrambled data to the Data EEPROM. Bank 0 Any code can go here READ BSF Protection Against Spurious Write Note: Power Consumption Considerations For the PIC16C84 Only; It is recommended that the EEADR<7:6> bits be cleared. When either of these bits is set, the maximum IDD for the device is higher than when both are cleared. The specification is 400 µA. With EEADR<7:6> cleared, the maximum is approximately 150 µA. REGISTERS/BITS ASSOCIATED WITH DATA EEPROM 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 08h EEDATA EEPROM data register xxxx xxxx uuuu uuuu 09h EEADR EEPROM address register xxxx xxxx uuuu uuuu 88h EECON1 89h EECON2 — — — EEPROM control register 2 EEIF WRERR WREN WR RD ---0 x000 ---0 q000 ---- ---- ---- ---- Legend: x = unknown, u = unchanged, - = unimplemented read as '0', q = value depends upon condition. Shaded cells are not used by Data EEPROM. 1995 Microchip Technology Inc. DS30081F-page 35 PIC16C8X NOTES: DS30081F-page 36 1995 Microchip Technology Inc. PIC16C8X 8.0 SPECIAL FEATURES OF THE CPU 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. This design keeps the device in reset while the power supply stabilizes. With these two timers on-chip, most applications need no external reset circuitry. What sets a microcontroller apart from other processors are special circuits to deal with the needs of real time applications. The PIC16C8X 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 features are: SLEEP mode offers a very low current power-down mode. The user can wake-up from SLEEP through external reset, Watchdog Timer time-out or through an interrupt. Several oscillator options are provided to allow the part to fit the application. The RC oscillator option saves system cost while the LP crystal option saves power. A set of configuration bits are used to select the various options. • OSC 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 8.1 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. Address 2007h is beyond the user program memory space and it belongs to the special test/configuration memory space (2000h - 3FFFh). This space can only be accessed during programming. The PIC16C8X 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 FIGURE 8-1: U-1 — bit13 U-1 — Configuration Bits CONFIGURATION WORD - PIC16C84 U-1 — U-1 — U-1 — U-1 — U-1 — U-1 — U-1 — R/P-u CP R/P-u R/P-u R/P-u R/P-u PWRTE WDTE FOSC1 FOSC0 bit0 R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘1’ - n = Value at POR reset u = unchanged bit 13:5 Unimplemented: Read as '1' bit 4 CP: Code Protection bit 1 = Code protection off 0 = All memory is code protected bit 3 PWRTE: Power-up Timer Enable bit 1 = Power-up timer is enabled 0 = Power-up timer is disabled bit 2 WDTE: Watchdog Timer Enable bit 1 = WDT enabled 0 = WDT disabled bit 1:0 FOSC1:FOSC0: Oscillator Selection bits 11 = RC oscillator 10 = HS oscillator 01 = XT oscillator 00 = LP oscillator 1995 Microchip Technology Inc. DS30081F-page 37 Thi d t t d ith F M k 404 PIC16C8X FIGURE 8-2: R-u CP bit13 CONFIGURATION WORD - PIC16CR83 AND PIC16CR84 R-u CP R-u CP R-u CP R-u CP R-u CP R/P-u DP R-u CP R-u CP R-u CP R-u R-u R-u R-u PWRTE WDTE FOSC1 FOSC0 bit0 R = Readable bit P = Programmable bit - n = Value at POR reset u = unchanged bit 13:8 CP: Program Memory Code Protection bit 1 = Code protection off 0 = Program memory is code protected bit 7 DP: Data Memory Code Protection bit 1 = Code protection off 0 = Data memory is code protected bit 6:4 CP: Program Memory Code Protection bit 1 = Code protection off 0 = Program memory is code protected bit 3 PWRTE: Power-up Timer Enable bit 1 = Power-up timer is disabled 0 = Power-up timer is enabled bit 2 WDTE: Watchdog Timer Enable bit 1 = WDT enabled 0 = WDT disabled bit 1:0 FOSC1:FOSC0: Oscillator Selection bits 11 = RC oscillator 10 = HS oscillator 01 = XT oscillator 00 = LP oscillator FIGURE 8-3: CONFIGURATION WORD - PIC16C83 AND PIC16C84A R/P-u R/P-u R/P-u R/P-u R/P-u R/P-u R/P-u R/P-u R/P-u CP CP CP CP CP CP CP CP CP bit13 R/P-u CP R/P-u R/P-u R/P-u R/P-u PWRTE WDTE FOSC1 FOSC0 bit0 R = Readable bit P = Programmable bit - n = Value at POR reset u = unchanged bit 13:4 CP: Code Protection bit 1 = Code protection off 0 = Program memory is code protected bit 3 PWRTE: Power-up Timer Enable bit 1 = Power-up timer is disabled 0 = Power-up timer is enabled bit 2 WDTE: Watchdog Timer Enable bit 1 = WDT enabled 0 = WDT disabled bit 1:0 FOSC1:FOSC0: Oscillator Selection bits 11 = RC oscillator 10 = HS oscillator 01 = XT oscillator 00 = LP oscillator DS30081F-page 38 1995 Microchip Technology Inc. PIC16C8X 8.2 Oscillator Configurations 8.2.1 OSCILLATOR TYPES TABLE 8-1: The PIC16C8X can be operated in four different oscillator modes. The user can program two configuration bits (FOSC1 and FOSC0) to select one of these four modes: • • • • LP XT HS RC Low Power Crystal Crystal/Resonator High Speed Crystal/Resonator Resistor/Capacitor Ranges Tested: Mode Freq XT 455 kHz 2.0 MHz 4.0 MHz 8.0 MHz 10.0 MHz HS Note : 8.2.2 CRYSTAL OSCILLATOR / CERAMIC RESONATORS In XT, LP or HS modes a crystal or ceramic resonator is connected to the OSC1/CLKIN and OSC2/CLKOUT pins to establish oscillation (Figure 8-4). FIGURE 8-4: CRYSTAL/CERAMIC RESONATOR OPERATION (HS, XT OR LP OSC CONFIGURATION) OSC1 To internal logic C1 XTAL RF SLEEP OSC2 C2 PIC16C84 CAPACITOR SELECTION FOR CERAMIC RESONATORS Resonators Tested: 455 kHz 2.0 MHz 4.0 MHz 8.0 MHz 10.0 MHz Panasonic EFO-A455K04B Murata Erie CSA2.00MG Murata Erie CSA4.00MG Murata Erie CSA8.00MT Murata Erie CSA10.00MTZ PIC16C83/R83/84A/R84 CAPACITOR SELECTION FOR CERAMIC RESONATORS See Table 8-1 and Table 8-3 for recommended values of C1 and C2. The PIC16C8X 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, LP or HS modes, the device can have an external clock source to drive the OSC1/CLKIN pin (Figure 8-5). FIGURE 8-5: EXTERNAL CLOCK INPUT OPERATION (HS, XT OR LP OSC CONFIGURATION) PIC16CXX Open OSC2 Ranges Tested: Mode Freq XT 455 kHz 2.0 MHz 4.0 MHz 8.0 MHz 10.0 MHz HS Note : OSC1/C1 OSC2/C2 47 - 100 pF 47 - 100 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF Recommended values of C1 and C2 are identical to the ranges tested table. Higher capacitance increases the stability of the oscillator but also increases the start-up time. These values are for design guidance only. Since each resonator has its own characteristics, the user should consult the resonator manufacturer for the appropriate values of external components. Resonators Tested: OSC1 Clock from ext. system ± 0.3% ± 0.5% ± 0.5% ± 0.5% ± 0.5% None of the resonators had built-in capacitors. PIC16CXX Note 1: A series resistor may be required for AT strip cut crystals. OSC2/C2 Recommended values of C1 and C2 are identical to the ranges tested table. Higher capacitance increases the stability of the oscillator but also increases the start-up time. These values are for design guidance only. Since each resonator has its own characteristics, the user should consult the resonator manufacturer for the appropriate values of external components. TABLE 8-2: RS Note1 OSC1/C1 47 - 100 pF 47 - 100 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 455 kHz 2.0 MHz 4.0 MHz 8.0 MHz 10.0 MHz Panasonic EFO-A455K04B Murata Erie CSA2.00MG Murata Erie CSA4.00MG Murata Erie CSA8.00MT Murata Erie CSA10.00MTZ ± 0.3% ± 0.5% ± 0.5% ± 0.5% ± 0.5% None of the resonators had built-in capacitors. 1995 Microchip Technology Inc. DS30081F-page 39 PIC16C8X TABLE 8-3: PIC16C84 CAPACITOR SELECTION FOR CRYSTAL OSCILLATOR Mode Freq LP 32 kHz 200 kHz 100 kHz 2 MHz 4 MHz 4 MHz 10 MHz XT HS Note : OSC1/C1 OSC2/C2 68 - 100 pF 68 - 100 pF 15 - 33 pF 15 - 33 pF 100 - 150 pF 100 - 150 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF Higher capacitance increases the stability of oscillator but also increases the start-up time. 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. For VDD > 4.5V, C1 = C2 ≈ 30 pF is recommended. Crystals Tested: 32.768 kHz 100 kHz 200 kHz 1.0 MHz 2.0 MHz 4.0 MHz 10.0 MHz Epson C-001R32.768K-A Epson C-2 100.00 KC-P STD XTL 200.000 KHz ECS ECS-10-13-2 ECS ECS-20-S-2 ECS ECS-40-S-4 ECS ECS-100-S-4 DS30081F-page 40 TABLE 8-4: PIC16C83/R83/84A/R84 CAPACITOR SELECTION FOR CRYSTAL OSCILLATOR Mode Freq OSC1/C1 OSC2/C2 LP 32 kHz 200 kHz 100 kHz 2 MHz 4 MHz 4 MHz 10 MHz 68 - 100 pF 15 - 33 pF 100 - 150 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 68 - 100 pF 15 - 33 pF 100 - 150 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF 15 - 33 pF XT HS Note : Higher capacitance increases the stability of oscillator but also increases the start-up time. 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. For VDD > 4.5V, C1 = C2 ≈ 30 pF is recommended. Crystals Tested: ± 20 PPM ± 20 PPM ± 20 PPM ± 50 PPM ± 50 PPM ± 50 PPM ± 50 PPM 32.768 kHz 100 kHz 200 kHz 1.0 MHz 2.0 MHz 4.0 MHz 10.0 MHz Epson C-001R32.768K-A Epson C-2 100.00 KC-P STD XTL 200.000 KHz ECS ECS-10-13-2 ECS ECS-20-S-2 ECS ECS-40-S-4 ECS ECS-100-S-4 ± 20 PPM ± 20 PPM ± 20 PPM ± 50 PPM ± 50 PPM ± 50 PPM ± 50 PPM 1995 Microchip Technology Inc. PIC16C8X 8.2.3 EXTERNAL CRYSTAL OSCILLATOR CIRCUIT 8.2.4 Either a prepackaged oscillator can be used or a simple oscillator circuit with TTL gates can be built. Prepackaged oscillators provide a wide operating range and better stability. A well-designed crystal oscillator will provide good performance with TTL gates. Two types of crystal oscillator circuits are available; one with series resonance, and one with parallel resonance. Figure 8-6 shows a parallel resonant oscillator circuit. The circuit is designed to use the fundamental frequency of the crystal. The 74AS04 inverter performs the 180-degree phase shift that a parallel oscillator requires. The 4.7 kΩ resistor provides negative feedback for stability. The 10 kΩ potentiometer biases the 74AS04 in the linear region. This could be used for external oscillator designs. FIGURE 8-6: EXTERNAL PARALLEL RESONANT CRYSTAL OSCILLATOR CIRCUIT +5V To Other Devices PIC16CXX 10k 74AS04 4.7k CLKIN 74AS04 10k XTAL 10k 20 pF 20 pF Figure 8-7 shows a series resonant oscillator circuit. This circuit is also designed to use the fundamental frequency of the crystal. The inverter performs a 180-degree phase shift. The 330 kΩ resistors provide the negative feedback to bias the inverters in their linear region. FIGURE 8-7: EXTERNAL SERIES RESONANT CRYSTAL OSCILLATOR CIRCUIT 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) values, 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 also affects the oscillation frequency, especially for low Cext values. The user needs to take into account variation due to tolerance of the external R and C components. Figure 8-8 shows how an R/C combination is connected to the PIC16C8X. For Rext values below 2.2 kΩ, the oscillator operation may become unstable, or stop completely. For very high Rext values (e.g., 1 MΩ), the oscillator becomes sensitive to noise, humidity and leakage. Thus, we recommend keeping Rext between 3 kΩ and 100 kΩ. Although the oscillator will operate with no external capacitor (Cext = 0 pF), we recommend using values above 20 pF for noise and stability reasons. With little or no external capacitance, the oscillation frequency can vary dramatically due to changes in external capacitances, such as PCB trace capacitance or package lead frame capacitance. See the electrical specification section for RC frequency variation from part to part due to normal process variation. The variation is larger for larger R (since leakage current variation will affect RC frequency more for large R) and for smaller C (since variation of input capacitance has a greater affect on RC frequency). See the electrical specification section for variation of oscillator frequency due to VDD for given Rext/Cext values as well as frequency variation due to operating temperature. The oscillator frequency, divided by 4, is available on the OSC2/CLKOUT pin, and can be used for test purposes or to synchronize other logic (see Figure 3-2 for waveform). FIGURE 8-8: RC OSCILLATOR MODE VDD Rext Internal clock OSC1 330 kΩ 330 kΩ 74AS04 74AS04 To Other Devices PIC16CXX Cext PIC16CXX VSS 74AS04 CLKIN Fosc/4 0.1 µF OSC2/CLKOUT XTAL Note: 1995 Microchip Technology Inc. When the device oscillator is in RC mode, do not drive the OSC1 pin with an external clock or you may damage the device. DS30081F-page 41 PIC16C8X 8.3 Reset 8.4 Power-on Reset (POR), Power-up Timer (PWRT) and Oscillator Start-up Timer (OST) 8.4.1 POWER-ON RESET (POR) The PIC16C8X differentiates between various kinds of reset: • • • • • Power-on Reset (POR) MCLR reset during normal operation MCLR reset during SLEEP WDT Reset (during normal operation) WDT Wake-up (during SLEEP) Some registers are not affected in any reset condition; their status is unknown on a POR reset and unchanged in any other reset. Most other registers are reset to a “reset state” on POR, MCLR or WDT reset during normal operation and on MCLR reset during SLEEP. They are not affected by a WDT reset during SLEEP, since this reset is viewed as the resumption of normal operation. The TO and PD bits are set or cleared differently in different reset situations (Table 8-6). These bits are used in software to determine the nature of the reset. Table 8-8 gives a full description of reset states for all registers. Figure 8-9 shows a simplified block diagram of the on-chip reset circuit. A Power-on Reset pulse is generated on-chip when VDD rise is detected (in the range of 1.2V - 1.7V). To take advantage of the POR, just tie the MCLR pin directly (or through a resistor) to VDD. This will eliminate external RC components usually needed to create Power-on Reset. A minimum rise time for VDD must be met for this to operate properly. See Electrical Specifications for details. When the device starts normal operation (exits the reset condition), device operating parameters (voltage, frequency, temperature, ...) must be meet 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." The POR circuit does not produce an internal reset when VDD declines. For all devices, except the PIC16C84, the MCLR reset path has a noise filter to ignore small pulses. The electrical specifications specifies the pulse width requirements for the MCLR pin. FIGURE 8-9: SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT External Reset MCLR WDT Module SLEEP WDT Time_Out Reset VDD rise detect Power_on_Reset S 10-bit Ripple counter R VDD OST/PWRT OST Chip_Reset Q OSC1/ CLKIN PWRT On-chip RC OSC(1) 10-bit Ripple counter Enable PWRT Note 1: This is a separate oscillator from the RC oscillator of the CLKIN pin. DS30081F-page 42 See Table 8-5 Enable OST 1995 Microchip Technology Inc. PIC16C8X 8.4.2 POWER-UP TIMER (PWRT) The Power-up Timer provides a fixed 72 ms nominal time-out on power-up only, from POR. The Power-up Timer operates on an internal RC oscillator. The chip is kept in reset as long as the PWRT is active. The PWRT delay allows the VDD to rise to an acceptable level. A configuration bit, PWRTE, can enable/disable the PWRT (see Figure 8-1, Figure 8-2, and Figure 8-3 for the operation of the PWRTE bit for a particular device). The power-up time delay will vary from chip to chip due to VDD, temperature, and process variation. See DC parameters for details. 8.4.3 8.4.4 TIME-OUT SEQUENCE On power-up (Figure 8-10, Figure 8-11, and Figure 8-12) the time-out sequence is as follows: First PWRT time-out is invoked after a POR has expired. Then the OST is activated. The total time-out will vary based on oscillator configuration and PWRTE configuration bit status. For example, in RC mode with the PWRT disabled, there will be no time-out at all. TABLE 8-5: TIME-OUT IN VARIOUS SITUATIONS Oscillator Configuration OSCILLATOR START-UP TIMER (OST) The Oscillator Start-up Timer (OST) provides a 1024 oscillator cycle delay (from OSC1 input) after the PWRT delay ends. This ensures 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. XT, HS, LP RC Power-up PWRT PWRT Enabled Disabled 72 ms + 1024TOSC 1024TOSC 72 ms — Wake-up from SLEEP 1024TOSC — Since the time-outs occur from the POR reset pulse, if MCLR is kept low long enough, the time-outs will expire. Then bringing MCLR high, execution will begin immediately (Figure 8-11). This is useful for testing purposes or to synchronize more than one PIC16CXX device when operating in parallel. Table 8-6 shows the significance of the TO and PD bits. Table 8-7 lists the reset conditions for some special registers, while Table 8-8 lists the reset conditions for all the registers. TABLE 8-6: TABLE 8-7: TO PD 1 0 x 0 0 1 1 1 x 0 1 0 1 0 STATUS BITS AND THEIR SIGNIFICANCE Condition Power-on Reset Illegal, TO is set on POR Illegal, PD is set on POR WDT Reset (during normal operation) WDT Wake-up MCLR Reset during normal operation MCLR Reset during SLEEP or interrupt wake-up from SLEEP RESET CONDITION FOR PROGRAM COUNTER AND THE STATUS REGISTER Condition Program Counter STATUS Register Power-on Reset 000h 0001 1xxx MCLR Reset during normal operation 000h 0001 1uuu MCLR Reset during SLEEP 000h 0001 0uuu WDT Reset (during normal operation) 000h 0000 1uuu WDT Wake-up PC + 1 uuu0 0uuu Interrupt wake-up from SLEEP PC + 1 (1) uuu1 0uuu Legend: u = unchanged, x = unknown. 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). 1995 Microchip Technology Inc. DS30081F-page 43 PIC16C8X TABLE 8-8: INITIALIZATION CONDITIONS FOR ALL REGISTERS Register W Address Power-on Reset MCLR Reset during: – normal operation – SLEEP WDT Reset during normal operation Wake-up from SLEEP: – through interrupt – through WDT time-out — xxxx xxxx uuuu uuuu uuuu uuuu INDF 00h ---- ---- ---- ---- ---- ---- TMR0 01h xxxx xxxx uuuu uuuu uuuu uuuu PCL 02h 0000h 0000h STATUS 03h 0001 1xxx 000q quuu(3) uuuq quuu(3) FSR 04h xxxx xxxx uuuu uuuu uuuu uuuu PORTA 05h ---x xxxx ---u uuuu ---u uuuu PORTB 06h xxxx xxxx uuuu uuuu uuuu uuuu EEDATA 08h xxxx xxxx uuuu uuuu uuuu uuuu EEADR 09h xxxx xxxx uuuu uuuu uuuu uuuu PCLATH 0Ah ---0 0000 ---0 0000 ---u uuuu INTCON 0Bh 0000 000x 0000 000u uuuu uuuu(1) INDF 80h ---- ---- ---- ---- ---- ---- OPTION 81h 1111 1111 1111 1111 uuuu uuuu PCL 82h 0000h 0000h PC + 1 STATUS 83h 0001 1xxx 000q quuu(3) uuuq quuu(3) FSR 84h xxxx xxxx uuuu uuuu uuuu uuuu TRISA 85h ---1 1111 ---1 1111 ---u uuuu TRISB 86h 1111 1111 1111 1111 uuuu uuuu EECON1 88h ---0 x000 ---0 q000 ---0 uuuu EECON2 89h ---- ---- ---- ---- ---- ---- PCLATH 8Ah ---0 0000 ---0 0000 ---u uuuu INTCON 8Bh 0000 000x 0000 000u uuuu uuuu(1) PC + 1(2) Legend: u = unchanged, x = unknown, - = unimplemented bit read as '0', q = value depends on condition. Note 1: One or more bits in INTCON will be affected (to cause wake-up). 2: When the wake-up is due to an interrupt and the GIE bit is set, the PC is loaded with the interrupt vector (0004h). 3: Table 8-7 lists the reset value for each specific condition. DS30081F-page 44 1995 Microchip Technology Inc. PIC16C8X FIGURE 8-10: 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 FIGURE 8-11: TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2 VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET FIGURE 8-12: TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD) VDD MCLR INTERNAL POR TPWRT PWRT TIME-OUT TOST OST TIME-OUT INTERNAL RESET 1995 Microchip Technology Inc. DS30081F-page 45 PIC16C8X FIGURE 8-13: EXTERNAL POWER-ON RESET CIRCUIT (FOR SLOW VDD POWER-UP) D VDD VDD VDD VDD FIGURE 8-14: BROWN-OUT PROTECTION CIRCUIT 1 33k R 10k MCLR R1 MCLR C 40k PIC16CXX Note 1: External Power-on Reset circuit is required only if VDD power-up rate is too slow. The diode D helps discharge the capacitor quickly when VDD powers down. 2: R < 40 kΩ is recommended to make sure that voltage drop across R does not exceed 0.2V (max leakage current spec on MCLR pin is 5 µA). A larger voltage drop will degrade VIH level on the MCLR pin. 3: R1 = 100Ω to 1 kΩ will limit any current flowing into MCLR from external capacitor C in the event of an MCLR pin breakdown due to ESD or EOS. PIC16CXX This circuit will activate reset when VDD goes below (Vz + 0.7V) where Vz = Zener voltage. FIGURE 8-15: BROWN-OUT PROTECTION CIRCUIT 2 VDD VDD R1 Q1 MCLR R2 40k PIC16CXX This brown-out circuit is less expensive, although less accurate. Transistor Q1 turns off when VDD is below a certain level such that: VDD • DS30081F-page 46 R1 R1 + R2 = 0.7V 1995 Microchip Technology Inc. PIC16C8X 8.5 Interrupts The PIC16C8X group has 4 sources of interrupt: • • • • External interrupt RB0/INT pin TMR0 overflow interrupt PORTB change interrupts (pins RB7:RB4) EEPROM write complete interrupt The interrupt control register (INTCON) records individual interrupt requests in flag bits. It also contains the individual and global interrupt enable bits. The global interrupt enable bit, GIE (INTCON<7>) enables (if set) all un-masked interrupts or disables (if cleared) all interrupts. Individual interrupts can be disabled through their corresponding enable bits in INTCON register. Bit GIE is cleared on reset. The “return from interrupt” instruction, RETFIE, exits interrupt routine as well as sets the GIE bit, which re-enable interrupts. The RB0/INT pin interrupt, the RB port change interrupt and the TMR0 overflow interrupt flags are contained in the INTCON register. 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. For external interrupt events, such as the RB0/INT pin or PORTB change interrupt, the interrupt latency will be three to four instruction cycles. The exact latency depends when the interrupt event occurs (Figure 8-17). The latency is the same for both one and two cycle instructions. 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 infinite interrupt requests. Note 1: Individual interrupt flag bits are set regardless of the status of their corresponding mask bit or the GIE bit. Note 2: For the PIC16C84 Only; If an interrupt occurs while the Global Interrupt Enable (GIE) bit is being cleared, the GIE bit may unintentionally be re-enabled by the user’s Interrupt Service Routine (the RETFIE instruction). The events that would cause this to occur are: 1. An instruction clears the GIE bit while an interrupt is acknowledged 2. The program branches to the Interrupt vector and executes the Interrupt Service Routine. 3. The Interrupt Service Routine completes with the execution of the RETFIE instruction. This causes the GIE bit to be set (enables interrupts), and the program returns to the instruction after the one which was meant to disable interrupts. The method to ensure that interrupts are globally disabled is: 1. LOOP 1995 Microchip Technology Inc. BCF Ensure that the GIE bit is cleared by the instruction, as shown in the following code: INTCON,GIE ;Disable All ; Interrupts BTFSC INTCON,GIE ;All Interrupts ; Disabled? GOTO LOOP ;NO, try again ; Yes, continue ; with program ; flow DS30081F-page 47 PIC16C8X FIGURE 8-16: INTERRUPT LOGIC Wake-up (If in SLEEP mode) T0IF T0IE INTF INTE Interrupt to CPU RBIF RBIE EEIF EEIE GIE FIGURE 8-17: 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 1 1 INTF flag (INTCON<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 = 3-4Tcy 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 RC oscillator mode. 4: For minimum width of INT pulse, refer to AC specs. 5: INTF is enabled to be set anytime during the Q4-Q1 cycles. DS30081F-page 48 1995 Microchip Technology Inc. PIC16C8X 8.5.1 8.6 INT INTERRUPT External interrupt on RB0/INT pin is edge triggered: either rising if INTEDG bit (OPTION<6>) is set, or falling, if INTEDG bit is clear. When a valid edge appears on the RB0/INT pin, the INTF bit (INTCON<1>) is set. This interrupt can be disabled by clearing control bit INTE (INTCON<4>). Flag bit INTF must be cleared in software via the interrupt service routine before re-enabling this interrupt. The INT interrupt can wake the processor from SLEEP (Section 8.8) only if the INTE bit was set prior to going into SLEEP. The status of the GIE bit decides whether the processor branches to the interrupt vector following wake-up. 8.5.2 TMR0 INTERRUPT An overflow (FFh → 00h) in TMR0 will set flag bit T0IF (INTCON<2>). The interrupt can be enabled/disabled by setting/clearing enable bit T0IE (INTCON<5>) (Section 6.0). 8.5.3 Context Saving During Interrupts During an interrupt, only the return PC value is saved on the stack. Typically, users wish to save key register values during an interrupt (e.g., W register and STATUS register). This is implemented in software. Example 8-1 stores and restores the STATUS and W register’s values. The User defined registers, W_TEMP and STATUS_TEMP are the temporary storage locations for the W and STATUS registers values. Example 8-1 does the following: a) b) c) d) e) Stores the W register. Stores the STATUS register in STATUS_TEMP. Executes the Interrupt Service Routine code. Restores the STATUS (and bank select bit) register. Restores the W register. PORT RB INTERRUPT An input change on PORTB<7:4> sets flag bit RBIF (INTCON<0>). The interrupt can be enabled/disabled by setting/clearing enable bit RBIE (INTCON<3>) (Section 5.2). Note 1: For the PIC16C84 Only; If a change on an I/O pin should occur when a read operation of PORTB is being executed (start of the Q2 cycle), the RBIF interrupt flag bit may not get set. Note 2: For all other PIC16C8X devices; For a change on the I/O pin to be recognized, the pulse width must be at least TCY wide. EXAMPLE 8-1: SAVING STATUS AND W REGISTERS IN RAM PUSH MOVWF SWAPF MOVWF : : : : SWAPF W_TEMP STATUS, W STATUS_TEMP MOVWF STATUS SWAPF SWAPF W_TEMP, F W_TEMP, W ISR POP STATUS_TEMP, W 1995 Microchip Technology Inc. ; ; ; : ; ; ; ; ; ; ; ; ; Copy W to TEMP register, Swap status to be saved into W Save status to STATUS_TEMP register Interrupt Service Routine should configure Bank as required Swap nibbles in STATUS_TEMP register and place result into W Move W into STATUS register (sets bank to original state) Swap nibbles in W_TEMP and place result in W_TEMP Swap nibbles in W_TEMP and place result into W DS30081F-page 49 PIC16C8X 8.7 Watchdog Timer (WDT) 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. 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. If the device is in SLEEP mode, a WDT Wake-up causes the device to wake-up and continue with normal operation. The WDT can be permanently disabled by programming configuration bit WDTE as a '0' (Section 8.1). 8.7.1 The CLRWDT and SLEEP instructions clear the WDT and the postscaler (if assigned to the WDT) and prevent it from timing out and generating a device RESET condition. The TO bit in the STATUS register will be cleared upon a WDT time-out. 8.7.2 WDT PROGRAMMING CONSIDERATIONS It should also be taken into account that under worst case conditions (VDD = Min., Temperature = Max., max. WDT prescaler) it may take several seconds before a WDT time-out occurs. 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 FIGURE 8-18: WATCHDOG TIMER BLOCK DIAGRAM From TMR0 Clock Source (Figure 6-6) 0 WDT Timer • 1 M U X Postscaler 8 8 - to -1 MUX PS2:PS0 • To TMR0 (Figure 6-6) PSA WDT Enable Bit 1 0 MUX PSA WDT Time-out Note: PSA and PS2:PS0 are bits in the OPTION register. TABLE 8-9: SUMMARY OF REGISTERS ASSOCIATED WITH THE WATCHDOG TIMER Address Name 2007h Config. bits 81h OPTION Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Value on Power-on Reset (2) (2) (2) CP PWRTE(1) WDTE FOSC1 FOSC0 (2) RBPU INTEDG T0CS T0SE PSA PS2 PS1 PS0 1111 1111 Value on all other resets 1111 1111 Legend: x = unknown. Shaded cells are not used by the WDT. Note 1: See Figure 8-1, Figure 8-2, and Figure 8-3 for operation of the PWRTE bit. 2: See Figure 8-1, Figure 8-2, Figure 8-3, and Section 8.9 for operation of the Code and Data protection bits. DS30081F-page 50 1995 Microchip Technology Inc. PIC16C8X 8.8 Power-down Mode (SLEEP) Peripherals cannot generate interrupts during SLEEP, since no on-chip Q clocks are present. The Power-down mode is entered by executing the SLEEP instruction. The first event (MCLR reset) will cause a device reset. The two latter events are considered a continuation of program execution. The TO and PD bits can be used to determine the cause of a device reset. The PD bit, which is set on power-up, is cleared when SLEEP is invoked. The TO bit is cleared if a WDT time-out occurred (and caused wake-up). If enabled, the Watchdog Timer will be cleared but keeps running, the PD bit (STATUS<3>) is cleared, the TO bit (STATUS<4>) 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). While 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 occurs 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. For the lowest current consumption, in SLEEP mode, place all I/O pins at either at VDD, or VSS, with no external circuitry drawing current from the I/O pin, and disable external clocks. I/O pins that are hi-impedance inputs should be pulled high or low externally to avoid switching currents caused by floating inputs. The T0CKI input should also be at VDD or VSS. The contribution from on-chip pull-ups on PORTB should be considered. The MCLR pin must be at a logic high level (VIHMC). It should be noted that a RESET generated by a WDT time-out does not drive the MCLR pin low. 8.8.1 Note: WAKE-UP FROM SLEEP If global interrupts are disabled (GIE cleared), but any interrupt source has both its interrupt enable bit and corresponding interrupt flag bits set, the device will immediately wake from sleep. The SLEEP instruction is completely executed. The device can wake-up from SLEEP through one of the following events: 1. 2. 3. External reset input on MCLR pin. WDT Wake-up (if WDT was enabled). Interrupt from RB0/INT pin, RB port change, or data EEPROM write complete. The WDT is cleared when the device wakes-up from sleep, regardless of the source of wake-up. FIGURE 8-19: WAKE-UP FROM SLEEP THROUGH INTERRUPT Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 OSC1 (1) tost(2) CLKOUT(4) INT pin Interrupt Latency (2) INTF flag (INTCON<1>) GIE bit (INTCON<7>) Processor in SLEEP INSTRUCTION FLOW PC Instruction fetched Instruction executed PC Inst (PC) = SLEEP Inst (PC-1) PC+1 PC+2 0004h (3) Inst (PC+1) Inst (PC+2) SLEEP Inst (PC+1) 0005h Dummy Cycle Note 1: XT or LP oscillator mode assumed. 2: Tost = 1024Tosc (drawing not to scale). This delay will not be there for RC osc mode. 3: When GIE is set, processor jumps to interrupt routine after wake-up. If GIE is clear, execution will continue in-line. 4: CLKOUT is not available in these osc modes, but shown here for timing reference. 1995 Microchip Technology Inc. DS30081F-page 51 PIC16C8X 8.9 Code Protection The code in the program memory and data EEPROM memory can be protected by programming the code protect bit (Figure 8-1, Figure 8-2, and Figure 8-3). 8.9.1 ROM DEVICES There are two protection configuration bits. One for the program memory, which is specified as part of the ROM code submittal. The second for the EEPROM data memory. When ROM devices complete testing, the EEPROM data memory code protect configuration bit will be programmed to the same state as the program memory code protect configuration bit. In applications where the device is code protected and the data EEPROM needs to be programmed before being placed in the application, the data EEPROM memory array needs to be erased and then the data memory code protect disabled. This will allow the desired data to be programmed into the device. The sequence to disable the data EEPROM memory protection is shown in the PIC16C84 Programming Specification (Literature number DS30189D) in Section 3.1.1. After programming the data EEPROM memory array, the data EEPROM memory code protect configuration bit should be programmed as desired. 8.10 ID Locations Four memory locations (2000h - 2003h) are designated as ID locations to store checksum or other code identification numbers. These locations are not accessible during normal execution but are readable and writable only during program/verify. Only the 4 least significant bits of ID location are usable. For ROM devices, these values are submitted along with the ROM code. 8.11 In-Circuit Serial Programming PIC16C8X 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. Customers can manufacture boards with unprogrammed devices, and then program the microcontroller just before shipping the product, allowing the most recent firmware or custom firmware to be programmed. The device is placed into a program/verify mode by holding the RB6 and RB7 pins low, while raising the MCLR pin from VIL to VIHH (see programming specification). RB6 becomes the programming clock and RB7 becomes the programming data. Both RB6 and RB7 are Schmitt Trigger inputs in this mode. After reset, to place the device into programming/verify mode, the program counter (PC) points to location 00h. A 6-bit command is then supplied to the device, 14-bits of program data is then supplied to or from the device, using load or read-type instructions. For complete details of serial programming, please refer to the PIC16CXX Programming Specifications (Literature #DS30189). FIGURE 8-20: TYPICAL IN-SYSTEM SERIAL PROGRAMMING CONNECTION External Connector Signals To Normal Connections PIC16CXX +5V VDD 0V VSS VPP MCLR CLK RB6 Data I/O RB7 To Normal Connections For ROM devices, both the program memory and Data EEPROM memory may be read, but only the Data EEPROM memory may be programmed. DS30081F-page 52 1995 Microchip Technology Inc. PIC16C8X 9.0 INSTRUCTION SET SUMMARY Each PIC16CXX 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 PIC16CXX instruction set summary in Table 9-2 lists byte-oriented, bit-oriented, and literal and control operations. Table 9-1 shows the opcode field descriptions. Byte-oriented instructions: 'f' represents a file register designator and 'd' represents a destination designator. The file register designator specifies which file register is to be used by the instruction. The destination designator specifies where the result of the operation is to be placed. If 'd' is 0, the result is placed in the W register. If 'd' is 1, the result is placed in the file register specified by the instruction. Bit-oriented instructions: 'b' represents a bit field designator which selects the number of the bit affected by the operation, while 'f' represents the address of the file in which the bit is located. Literal and control operations: 'k' represents an eight or eleven bit constant or literal value. TABLE 9-1: OPCODE FIELD DESCRIPTIONS Field • Byte-oriented • Bit-oriented • Literal and control All instructions are executed within a single instruction cycle, unless a conditional test is true or the program counter is changed as a result of the instruction. The execution takes two instruction cycles with the second cycle executed as a NOP. Each cycle consists of four oscillator periods. Thus, for an oscillator frequency of 4 MHz, the normal instruction execution time is 1 µs. The instruction execution time is 2 µs for program branches. Table 9-2 lists the instructions Microchip’s assembler (MPASM). Description Figure 9-1 shows the three general formats of instructions. Note: 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. All examples use the following format to represent a hexadecimal number: Bit-oriented file register operations 13 10 9 7 6 OPCODE b (BIT #) f (FILE #) Top of Stack PCLATH Program Counter High Latch Global Interrupt Enable bit TO Time-out bit PD Power-down bit Literal and control operations General 13 8 7 OPCODE dest Destination (Either the W register or the specified register file location) 0 k (literal) k = 8-bit immediate value [ ] Options ( ) Contents → Assigned to <> Register bit field OPCODE In the set of k = 11-bit immediate value ∈ 0 b = 3-bit bit address f = 7-bit file register address Program Counter Watchdog Timer/Counter 0 d = 0 for destination W d = 1 for destination f f = 7-bit file register address label Label name GIE GENERAL FORMAT FOR INSTRUCTIONS Byte-oriented file register operations 13 8 7 6 OPCODE d f (FILE #) Destination select; d = 0: store result in W, d = 1: store result in file register f. Default is d = 1 WDT To maintain upward compatibility with future PIC16CXX products, do not use the OPTION and TRIS instructions. FIGURE 9-1: Register file address (0x00 to 0x7F) PC by 0xhh W TOS recognized where h signifies a hexadecimal digit. f d The instruction set is highly orthogonal and is grouped into three basic categories: CALL and GOTO instructions only 13 11 10 0 k (literal) italics User defined term (font is courier) 1995 Microchip Technology Inc. DS30081F-page 53 Thi d t t d ith F M k 404 PIC16C8X TABLE 9-2: INSTRUCTION SET SUMMARY Mnemonic, Operands ADDWF ANDWF CLRF CLRW COMF DECF DECFSZ INCF INCFSZ IORWF MOVF MOVWF NOP RLF RRF SUBWF SWAPF XORWF Description Cycles 14-Bit Opcode MSb 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 LSb Status Affected Notes 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 0xxx dfff dfff dfff dfff dfff dfff dfff lfff 0xx0 dfff dfff dfff dfff dfff ffff ffff ffff xxxx ffff ffff ffff ffff ffff ffff ffff ffff 0000 ffff ffff ffff ffff ffff C,DC,Z Z Z Z Z Z None Z None Z Z None None C C C,DC,Z None Z 1,2 1,2 2 1 1 1 (2) 1 (2) 01 01 01 01 00bb 01bb 10bb 11bb bfff bfff bfff bfff ffff ffff ffff ffff None None None None 1,2 1,2 3 3 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 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 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 TO,PD None Z None None None None 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 TMR0. 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. DS30081F-page 54 1995 Microchip Technology Inc. PIC16C8X 9.1 Instruction Descriptions ANDLW AND Literal with W Syntax: [ label ] ANDLW 0 ≤ k ≤ 255 Operands: 0 ≤ k ≤ 255 (W) + k → (W) Operation: (W) .AND. (k) → (W) C, DC, Z Status Affected: Z ADDLW Add Literal and W Syntax: [ label ] ADDLW Operands: Operation: Status Affected: Encoding: 11 k 111x kkkk kkkk Encoding: 11 Description: The contents of the W register are added to the eight bit literal 'k' and the result is placed back in the W register. Description: Words: 1 Words: 1 1 Cycles: 1 Cycles: Example ADDLW = = ADDWF Add W and f Syntax: [ label ] ADDWF Operands: ANDLW = 0xA3 After Instruction W 0x25 = 0x03 ANDWF AND W with f Syntax: [ label ] ANDWF 0 ≤ f ≤ 127 d ∈ [0,1] Operands: 0 ≤ f ≤ 127 d ∈ [0,1] Operation: (W) + (f) → (dest) Operation: (W) .AND. (f) → (dest) Status Affected: C, DC, Z Status Affected: Z Encoding: 00 kkkk 0x5F W 0x10 After Instruction W kkkk Before Instruction Before Instruction W 1001 The contents of W register is AND’ed with the eight bit literal 'k'. The result is placed back in the W register. Example 0x15 k f,d 0111 dfff ffff Encoding: 00 f,d 0101 dfff ffff Description: Add the contents of the W register to 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'. 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'. Words: 1 Words: 1 Cycles: 1 Cycles: 1 Example ADDWF FSR, 0 Before Instruction W = FSR = 1995 Microchip Technology Inc. ANDWF FSR, 1 Before Instruction 0x17 0xC2 After Instruction W = FSR = Example W = FSR = 0x17 0xC2 After Instruction 0xD9 0xC2 W = FSR = 0x17 0x02 DS30081F-page 55 PIC16C8X BTFSC Bit Test f, Skip if Clear Syntax: [ label ] BTFSC f,b 0 ≤ f ≤ 127 0≤b≤7 Operands: 0 ≤ f ≤ 127 0≤b≤7 Operation: 0 → (f<b>) Operation: skip if (f<b>) = 0 Status Affected: None Status Affected: None BCF Bit Clear f Syntax: [ label ] BCF Operands: Encoding: 01 f,b 00bb bfff ffff Description: Bit 'b' in register 'f' is cleared. Words: 1 Cycles: 1 Example BCF Encoding: FLAG_REG = 0xC7 After Instruction FLAG_REG = 0x47 10bb bfff ffff Description: Words: 1 Cycles: 1(2) FLAG_REG, 7 Before Instruction 01 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. Example HERE FALSE TRUE BTFSC GOTO • • • FLAG,1 PROCESS_CODE Before Instruction PC = address HERE After Instruction if FLAG<1>=0, PC=address if FLAG<1>=1, PC=address BSF Bit Set f Syntax: [ label ] BSF Operands: 0 ≤ f ≤ 127 0≤b≤7 Operation: 1 → (f<b>) Status Affected: None Encoding: 01 01bb bfff Bit 'b' in register 'f' is set. Words: 1 Cycles: 1 BSF FALSE f,b Description: Example TRUE FLAG_REG, ffff 7 Before Instruction FLAG_REG= 0x0A After Instruction FLAG_REG= 0x8A DS30081F-page 56 1995 Microchip Technology Inc. PIC16C8X BTFSS Bit Test f, skip if Set CLRF Clear f Syntax: [ label ] BTFSS f,b Syntax: [ label ] CLRF Operands: 0 ≤ f ≤ 127 0≤b<7 Operands: 0 ≤ f ≤ 127 Operation: 00h → (f) 1→Z Status Affected: Z Operation: skip if (f<b>) = 1 Status Affected: None 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. Words: 1 Cycles: 1(2) Example HERE FALSE TRUE Encoding: 00 f 0001 1fff ffff Description: The contents of register 'f' are cleared and the Z bit is set. Words: 1 Cycles: 1 Example CLRF FLAG_REG Before Instruction FLAG_REG BTFSC GOTO • • • = 0x5A = = 0x00 1 After Instruction FLAG,1 PROCESS_CODE FLAG_REG Z Before Instruction PC = address HERE After Instruction if FLAG<1>=0, PC=address if FLAG<1>=1, PC=address FALSE TRUE CALL Subroutine Call CLRW Clear W Register Syntax: [ label ] CALL k Syntax: [ label ] CLRW Operands: 0 ≤ k ≤ 2047 Operands: None Operation: (PC)+ 1→ TOS, k → (PC<10:0>), (PCLATH<4:3>) → (PC<12:11>) Operation: 00h → (W) 1→Z Status Affected: Z Status Affected: None Encoding: Encoding: Description: 10 kkkk kkkk Subroutine call. 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 Description: 00 0xxx xxxx W register is cleared. Zero bit (Z) is set. Words: 1 Cycles: 1 Example 0001 CLRW Before Instruction W HERE CALL THERE Before Instruction PC = = 0x5A After Instruction W Z = = 0x00 1 Address HERE After Instruction PC = TOS = 1995 Microchip Technology Inc. Address THERE Address HERE DS30081F-page 57 PIC16C8X 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 Status Affected: Encoding: Description: Encoding: TO, PD 00 0000 0110 0100 The CLRWDT instruction resets the watchdog timer. It also resets the prescaler of the WDT. Status bits TO and PD are set. Words: 1 Cycles: 1 Example Description: 00 0011 dfff ffff 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'. Words: 1 Cycles: 1 Example DECF CNT, 1 Before Instruction CLRWDT CNT Z Before Instruction WDT counter = COMF Complement f Syntax: [ label ] COMF Operands: 0x01 0 = = 0x00 1 After Instruction ? CNT Z After Instruction WDT counter = WDT prescale = TO = PD = = = 0x00 0 1 1 DECFSZ Decrement f, Skip if 0 Syntax: [ label ] DECFSZ f,d 0 ≤ f ≤ 127 d ∈ [0,1] Operands: 0 ≤ f ≤ 127 d ∈ [0,1] Operation: ( f ) → (dest) Operation: (f) – 1 → (dest); skip if result = 0 Status Affected: Z Status Affected: None Encoding: 00 1001 f,d 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 Example COMF REG1,0 Before Instruction REG1 = 0x13 = = 0x13 0xEC After Instruction REG1 W Encoding: Description: 00 dfff ffff 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) Example 1011 HERE DECFSZ GOTO CONTINUE • • • CNT, 1 LOOP Before Instruction PC = addressHERE After Instruction CNT if CNT PC if CNT PC DS30081F-page 58 = = = ≠ = CNT - 1 0, address CONTINUE 0, address HERE+1 1995 Microchip Technology Inc. PIC16C8X GOTO Go to address 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: Description: 00 INCFSZ f,d 1111 dfff ffff 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 1 INCFSZ GOTO CONTINUE • • • CNT, LOOP Before Instruction PC = addressHERE After Instruction CNT = if CNT = PC = if CNT≠ PC = CNT + 1 0, addressCONTINUE 0, addressHERE +1 INCF Increment f IORLW Inclusive OR Literal with W Syntax: [ label ] Syntax: [ label ] Operands: 0 ≤ f ≤ 127 d ∈ [0,1] Operands: 0 ≤ k ≤ 255 Operation: (f) + 1 → (dest) (W) .OR. (k) → (W) Operation: Status Affected: Z Status Affected: Z Encoding: Description: Encoding: 00 1010 dfff ffff 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 f,d kkkk kkkk The contents of the W register are OR’ed to the eight bit literal 'k'. The result is placed in the W register. Words: 1 Cycles: 1 IORLW 0x35 Before Instruction CNT, 1 W Before Instruction CNT Z 1000 Description: Example INCF 11 IORLW k = 0x9A After Instruction = = 0xFF 0 = = 0x00 1 W = 0xBF After Instruction CNT Z 1995 Microchip Technology Inc. DS30081F-page 59 PIC16C8X 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) → (W) Operation: (f) → (dest) Status Affected: Z Status Affected: Z Encoding: 00 IORWF f,d 0100 dfff ffff Description: Inclusive OR the W register to 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 IORWF RESULT, 0 Before Instruction RESULT = W = Encoding: Description: 00 1000 Words: 1 Cycles: 1 MOVF FSR, 0 W =value in FSR register RESULT = W = 0x13 0x93 MOVLW Move literal to W MOVWF Move W to f Syntax: [ label ] Syntax: [ label ] Operands: 0 ≤ k ≤ 255 Operands: 0 ≤ f ≤ 127 Operation: k → (W) Operation: (W) → (f) Status Affected: None Status Affected: None 11 MOVLW k 00XX kkkk kkkk Description: The eight bit literal 'k' is loaded into W register. The don’t cares will assemble as 0’s. Words: 1 Cycles: 1 Example Encoding: 0x5A = 0000 f 1fff ffff Move data from W register to register 'f'. Words: 1 Cycles: 1 MOVWF OPTION Before Instruction After Instruction W 00 MOVWF Description: Example MOVLW ffff After Instruction After Instruction Encoding: dfff The contents of register f is moved to destination 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. Example 0x13 0x91 MOVF f,d 0x5A OPTION = W = 0xFF 0x4F After Instruction OPTION = W = DS30081F-page 60 0x4F 0x4F 1995 Microchip Technology Inc. PIC16C8X 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 0xx0 0000 RETFIE No operation. Encoding: Words: 1 Description: Cycles: 1 The Stack is popped and Top of Stack (TOS) is loaded into the PC. Interrupts are enabled by setting the Global Interrupt Enable bit. This is a two cycle instruction. Words: 1 Cycles: 2 Description: Example 00 NOP Example 0000 0000 1001 RETFIE After Interrupt PC = GIE = TOS 1 OPTION Load Option Register RETLW Return Literal to W Syntax: [ label ] Syntax: [ label ] Operands: None Operands: 0 ≤ k ≤ 255 Operation: (W) → OPTION Operation: k → (W), TOS → (PC) Status Affected: None OPTION Status Affected: None Encoding: Description: Words: Cycles: 00 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. Description: 11 01xx Words: 1 1 Cycles: 2 Example CALL TABLE To maintain upward compatibility with future PIC16CXX products, do not use this instruction. 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 Example Note: Encoding: RETLW k • • • TABLE ADDWF RETLW RETLW • • • RETLW ;W contains table ;offset value ;W now has table value PC k1 k2 ;W = offset ;Begin table ; kn ; End of table Before Instruction W = 0x07 After Instruction W 1995 Microchip Technology Inc. = value of k7 DS30081F-page 61 PIC16C8X 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 popped and the Top of 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 C PC = TOS Words: 1 Cycles: 1 Example 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'. RETURN After Interrupt dfff Register f RRF REG1,0 Before Instruction REG1 C = = 1110 0110 0 = = = 1110 0110 0111 0011 1 After Instruction REG1 W C RLF Rotate Left f through Carry SLEEP Go into Standby Mode Syntax: [ label ] Syntax: [ label ] Operands: 0 ≤ f ≤ 127 d ∈ [0,1] Operands: None Operation: 00h → WDT, 0 → WDT prescaler 1 → TO, 0 → PD Status Affected: TO, PD RLF f,d Operation: See description below Status Affected: C Encoding: Description: 00 1101 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 Words: 1 Cycles: 1 Example dfff RLF Encoding: Before Instruction REG1 C = = 1110 0110 0 = = = 1110 0110 1100 1100 1 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 REG1,0 00 SLEEP After Instruction REG1 W C DS30081F-page 62 1995 Microchip Technology Inc. PIC16C8X SUBLW Subtract W from Literal SUBWF Subtract W from f Syntax: [ label ] Syntax: [ label ] Operands: 0 ≤ k ≤ 255 Operands: Operation: k – (W) → (W) 0 ≤ f ≤ 127 d ∈ [0,1] Status Affected: C, DC, Z Encoding: Description: 11 SUBLW k 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 = 1 = ? Operation: (f) – (W) → (dest) Status Affected: C, DC, Z Encoding: Example 2: Example 3: Cycles: 1 Example 1: SUBWF REG1 = 3 W = 2 C = ? After Instruction = 2 = ? REG1 = 1 W = 2 C = 1; result is positive Example 2: Before Instruction REG1 = 2 W = 2 C = ? = 3 = ? After Instruction After Instruction W C REG1,1 Before Instruction Before Instruction W C ffff 1 = 1 = 1; result is positive = 0 = 1; result is zero dfff Words: After Instruction W C 0010 Subtract (2’s complement methodize 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 00 Description: After Instruction W C SUBWF f,d REG1 = 0 W = 2 C = 1; result is zero = FF = 0; result is negative Example 3: Before Instruction REG1 = 1 W = 2 C = ? After Instruction REG1 = FF W = 2 C = 0; result is negative 1995 Microchip Technology Inc. DS30081F-page 63 PIC16C8X SWAPF Swap f Syntax: [ label ] Operands: 0 ≤ f ≤ 127 d ∈ [0,1] Operation: (f<3:0>) → (dest<7:4>), (f<7:4>) → (dest<3:0>) Status Affected: 00 1 Cycles: 1 Example Syntax: [ label ] Operands: 0 ≤ k ≤ 255 Operation: (W) .XOR. k → (W) Status Affected: Z Description: 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: Exclusive OR Literal with W Encoding: None Encoding: Description: SWAPF f,d XORLW XORLW k 11 1010 kkkk kkkk 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 W SWAP F REG, 0 0xB5 After Instruction Before Instruction REG1 = W = 0xA5 = = 0xA5 0x5A = 0x1A After Instruction REG1 W TRIS Load TRIS Register XORWF Exclusive OR W with f Syntax: [ label ] XORWF Operands: 0 ≤ f ≤ 127 d ∈ [0,1] Operation: (W) .XOR. (f) → (dest) Status Affected: Z Syntax: [ label ] TRIS Operands: 5≤f≤7 Operation: (W) → TRIS register (f) f Status Affected: None Encoding: Description: 00 0000 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. Words: 1 Cycles: 1 Example Note: To maintain upward compatibility with future PIC16CXX products, do not use this instruction. Encoding: Description: 00 0110 f,d dfff 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'. Words: 1 Cycles: 1 Example XORWF REG 1 Before Instruction REG W = = 0xAF 0xB5 = = 0x1A 0xB5 After Instruction REG W DS30081F-page 64 1995 Microchip Technology Inc. PIC16C8X 10.0 DEVELOPMENT SUPPORT 10.1 Development Tools The PIC16/17 microcontrollers are supported with a full range of hardware and software development tools: • • • • • • • • • PICMASTER Real-Time In-Circuit Emulator PRO MATE Universal Programmer PICSTART Low-Cost Prototype Programmer PICDEM-1 Low-Cost Demonstration Board PICDEM-2 Low-Cost Demonstration Board MPASM Assembler MPSIM Software Simulator C Compiler (MP-C) Fuzzy logic development system (fuzzyTECH−MP) 10.2 The PICMASTER Emulator System has been designed as a real-time emulation system with advanced features that are generally found on more expensive development tools. The PC compatible 386 (and better) machine platform and Microsoft Windows 3.x environment was chosen to best make these features available to you, the end user. The PICMASTER Universal Emulator System consists primarily of four major components: • • • • Host-Interface Card Emulator Control Pod Target-Specific Emulator Probe PC-Host Emulation Control Software The Windows operating system allows the developer to take full advantage of the many powerful features and functions of the PICMASTER system. PICMASTER emulation can operate in one window, while a text editor is running in a second window. PICMASTER: High Performance Universal In-Circuit Emulator with MPLAB IDE The PICMASTER Universal In-Circuit Emulator (Figure 10-1) is intended to provide the product development engineer with a complete microcontroller design tool set for all microcontrollers in the PIC16C5X, PIC16CXX and PIC17CXX families. PICMASTER is supplied with the MPLAB Integrated Development Environment (IDE), which allows editing, "make" and download, and source debugging from a single environment. Interchangeable target probes allow the system to be easily reconfigured for emulation of different processors. The universal architecture of the PICMASTER allows expansion to support all new PIC16C5X, PIC16CXX and PIC17CXX microcontrollers. PC-Host Emulation Control software takes full advantage of Dynamic Data Exchange (DDE), a feature of Windows. DDE allows data to be dynamically transferred between two or more Windows programs. With this feature, data collected with PICMASTER can be automatically transferred to a spreadsheet or database program for further analysis. Under Windows, as many as four PICMASTER emulators can be run simultaneously from the same PC making development of multi-microcontroller systems possible (e.g., a system containing a PIC16CXX processor and a PIC17CXX processor). The PICMASTER probes specifications are shown in Table 10-1. FIGURE 10-1: PICMASTER SYSTEM CONFIGURATION 5 VDC Windows 3.x PC Bus In-Line Power Supply (Optional) 90 - 250 VAC Power Switch Power Connector Interchangeable Emulator Probe PC-Interface PICMASTER Emulator Pod Common Interface Card PC Compatible Computer Logic Probes 1995 Microchip Technology Inc. DS30081F-page 65 Thi d t t d ith F M k 404 PIC16C8X TABLE 10-1: PICMASTER PROBE SPECIFICATION TABLE 10-1: PICMASTER PROBE SPECIFICATION PROBE Devices PICMASTER PROBE Maximum Frequency Operating Voltage PROBE Devices PICMASTER PROBE Maximum Frequency Operating Voltage PIC16C54 PROBE-16D 20 MHz 4.5V - 5.5V PIC16C65 PROBE-16F 10 MHz 4.5V - 5.5V PIC16C54A PROBE-16D 20 MHz 4.5V - 5.5V PIC16C65A PROBE-16F(1) 10 MHz 4.5V - 5.5V PIC16CR54 PROBE-16D 20 MHz 4.5V - 5.5V PIC16C620 PROBE-16H 10 MHz 4.5V - 5.5V PIC16CR54A PROBE-16D(1) 20 MHz 4.5V - 5.5V PIC16C621 PROBE-16H 10 MHz 4.5V - 5.5V PIC16CR54B PROBE-16D(1) 20 MHz 4.5V - 5.5V PIC16C622 PROBE-16H 10 MHz 4.5V - 5.5V PROBE-16D 20 MHz 4.5V - 5.5V PIC16C70 PROBE-16B(1) 10 MHz 4.5V - 5.5V PROBE-16D(1) 20 MHz 4.5V - 5.5V PIC16C71 PROBE-16B PROBE-16D 20 MHz 4.5V - 5.5V PROBE-16D(1) 20 MHz 4.5V - 5.5V PIC16C57 PROBE-16D 20 MHz 4.5V - 5.5V PIC16CR57A PROBE-16D 20 MHz 4.5V - 5.5V PIC16C73A PIC16CR57B PROBE-16D(1) 20 MHz 4.5V - 5.5V PIC16C74 PIC16C58A PROBE-16D 20 MHz 4.5V - 5.5V PIC16C74A PIC16CR58A PROBE-16D 20 MHz 4.5V - 5.5V PIC16C83 PROBE-16C PIC16C55 PIC16CR55 PIC16C56 PIC16CR56 PIC16CR58B (1) 4.5V - 5.5V PIC16C71A PROBE-16B 10 MHz 4.5V - 5.5V PIC16C72 PROBE-16F(1) 10 MHz 4.5V - 5.5V PIC16C73 PROBE-16F 10 MHz 4.5V - 5.5V PROBE-16F(1) 10 MHz 4.5V - 5.5V PROBE-16F 10 MHz 4.5V - 5.5V 10 MHz 4.5V - 5.5V 10 MHz 4.5V - 5.5V (1) PROBE-16F 20 MHz 4.5V - 5.5V PIC16C84 PROBE-16C 10 MHz 4.5V - 5.5V PIC16C61 PROBE-16G 10 MHz 4.5V - 5.5V PIC17C42 PROBE-17B 20 MHz 4.5V - 5.5V PIC16C62 PROBE-16E 10 MHz 4.5V - 5.5V PIC17C43 PROBE-17B 20 MHz 4.5V - 5.5V PIC16C62A PROBE-16E(1) 10 MHz 4.5V - 5.5V PIC17C44 PROBE-17B 20 MHz 4.5V - 5.5V PIC16CR62 (1) PROBE-16E 10 MHz 4.5V - 5.5V PIC16C63 PROBE-16F(1) 10 MHz 4.5V - 5.5V PIC16C64 PROBE-16E Note 1: This PICMASTER probe can be used to functionally emulate the device listed in the previous column. Contact your Microchip sales office for details. PIC16C64A PIC16CR64 PROBE-16D 10 MHz (1) 10 MHz 4.5V - 5.5V (1) 10 MHz 4.5V - 5.5V (1) 10 MHz 4.5V - 5.5V PROBE-16E PROBE-16E DS30081F-page 66 1995 Microchip Technology Inc. PIC16C8X 10.3 PRO MATE: Universal Programmer The PRO MATE Universal Programmer is a full-featured programmer capable of operating in stand-alone mode as well as PC-hosted mode. The PRO MATE has programmable VDD and VPP supplies which allows it to verify programmed memory at VDD min and VDD max for maximum reliability. It has an LCD display for displaying error messages, keys to enter commands and a modular detachable socket assembly to support various package types. In stand- alone mode the PRO MATE can read, verify or program PIC16C5X, PIC16CXX and PIC17CXX devices. It can also set configuration and code-protect bits in this mode. In PC-hosted mode, the PRO MATE connects to the PC via one of the COM (RS-232) ports. PC based user-interface software makes using the programmer simple and efficient. The user interface is full-screen and menu-based. Full screen display and editing of data, easy selection of bit configuration and part type, easy selection of VDD min, VDD max and VPP levels, load and store to and from disk files (Intel hex format) are some of the features of the software. Essential commands such as read, verify, program and blank check can be issued from the screen. Additionally, serial programming support is possible where each part is programmed with a different serial number, sequential or random. The PRO MATE has a modular “programming socket module”. Different socket modules are required for different processor types and/or package types. PRO MATE supports all PIC16C5X, PIC16CXX and PIC17CXX processors. 10.4 PICSTART Low-Cost Development System The PICSTART programmer is an easy to use, very low-cost prototype programmer. It connects to the PC via one of the COM (RS-232) ports. A PC-based user interface software makes using the programmer simple and efficient. The user interface is full-screen and menu-based. PICSTART is not recommended for production programming. 1995 Microchip Technology Inc. 10.5 PICDEM-1 Low-Cost PIC16/17 Demonstration Board The PICDEM-1 is a simple board which demonstrates the capabilities of several of Microchip’s microcontrollers. The microcontrollers supported are: PIC16C5X (PIC16C54 to PIC16C58A), PIC16C61, PIC16C62X, PIC16C71, PIC16C8X, PIC17C42, PIC17C43 and PIC17C44. All necessary hardware and software is included to run basic demo programs. The users can program the sample microcontrollers provided with the PICDEM-1 board, on a PRO MATE or PICSTART-16B programmer, and easily test firmware. The user can also connect the PICDEM-1 board to the PICMASTER emulator and download the firmware to the emulator for testing. Additional prototype area is available for the user to build some additional hardware and connect it to the microcontroller socket(s). Some of the features include an RS-232 interface, a potentiometer for simulated analog input, push-button switches and eight LEDs connected to PORTB. 10.6 PICDEM-2 Low-Cost PIC16CXX Demonstration Board The PICDEM-2 is a simple demonstration board that supports the 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 programmer or PICSTART-16C, and easily test firmware. The PICMASTER emulator may also be used with the PICDEM-2 board to test firmware. Additional prototype area has been provided to the user for adding additional hardware and connecting it to the microcontroller socket(s). Some of the features include a RS-232 interface, push-button switches, a potentiometer for simulated analog input, a Serial EEPROM to demonstrate usage of the I2C bus and separate headers for connection to an LCD module and a keypad. DS30081F-page 67 PIC16C8X 10.7 MPLAB Integrated Development Environment Software The MPLAB Software brings an ease of software development previously unseen in the 8-bit microcontroller market. MPLAB is a windows based application which contains: • A full featured editor • Three operating modes - editor - emulator - simulator (available soon) • A project manager • Customizable tool bar and key mapping • A status bar with project information • Extensive on-line help MPLAB allows you to: • edit your source files (either assembly or "C") • one touch assemble (or compile) and download to PIC16/17 tools (automatically updates all project information) • debug using: - source files - absolute listing file • transfer data dynamically via DDE (soon to be replaced by OLE) • run up to four emulators on the same PC The ability to use MPLAB with Microchip’s simulator (available soon) allows a consistent platform and the ability to easily switch from the low cost simulator to the full featured emulator with minimal retraining due to development tools. DS30081F-page 68 10.8 Assembler (MPASM) The MPASM Cross Assembler is a PC-hosted symbolic assembler. It supports all microcontroller series including the PIC16C5X, PIC16CXX, and PIC17CXX families. MPASM offers full featured Macro capabilities, conditional assembly, and several source and listing formats. It generates various object code formats to support Microchip's development tools as well as third party programmers. MPASM allows full symbolic debugging from the Microchip Universal Emulator System (PICMASTER). MPASM has the following features to assist in developing software for specific use applications. • Provides translation of Assembler source code to object code for all Microchip microcontrollers. • Macro assembly capability • Produces all the files (Object, Listing, Symbol, and special) required for symbolic debug with Microchip’s emulator systems. • Supports Hex (default), Decimal and Octal source and listing formats. MPASM provides a rich directive language to support programming of the PIC16/17. Directives are helpful in making the development of your assemble source code shorter and more maintainable. • Data Directives are those that control the allocation of memory and provide a way to refer to data items symbolically (i.e., by meaningful names). • Control Directives control the MPASM listing display. They allow the specification of titles and sub-titles, page ejects and other listing control. This eases the readability of the printed output file. • Conditional Directives permit sections of conditionally assembled code. This is most useful where additional functionality may wished to be added depending on the product (less functionality for the low end product, then for the high end product). Also this is very helpful in the debugging of a program. • Macro Directives control the execution and data allocation within macro body definitions. This makes very simple the re-use of functions in a program as well as between programs. 1995 Microchip Technology Inc. PIC16C8X 10.9 Software Simulator (MPSIM) The MPSIM Software Simulator allows code development in a PC host environment. It allows the user to simulate the PIC16/17 series microcontrollers on an instruction level. On any given instruction, the user may examine or modify any of the data areas or provide external stimulus to any of the pins. The input/output radix can be set by the user and the execution can be performed in; single step, execute until break, or in a trace mode. MPSIM fully supports symbolic debugging using MP-C and MPASM. The Software Simulator offers the low cost flexibility to develop and debug code outside of the laboratory environment making it an excellent multi-project software development tool. 10.10 10.11 Fuzzy Logic Development System (fuzzyTECH-MP) fuzzyTECH-MP fuzzy logic development tool is available in two versions - a low cost introductory version, MP Explorer, for designers to gain a comprehensive working knowledge of fuzzy logic system design; and a full-featured version, fuzzyTECH-MP, edition for implementing more complex systems. Both versions include Microchip’s fuzzyLAB demonstration board for hands-on experience with fuzzy logic systems implementation. 10.12 Development Systems For convenience, the development tools are packaged into comprehensive systems as listed in Table 10-2. C Compiler (MP-C) The MP-C Code Development System is a complete 'C' compiler and integrated development environment for Microchip’s PIC16/17 family of microcontrollers. The compiler provides powerful integration capabilities and ease of use not found with other compilers. For easier source level debugging, the compiler provides symbol information that is compatible with the PICMASTER Universal Emulator memory display (PICMASTER emulator software versions 1.13 and later). The MP-C Code Development System is supplied directly by Byte Craft Limited of Waterloo, Ontario, Canada. If you have any questions, please contact your regional Microchip FAE or Microchip technical support personnel at (602) 786-7627. TABLE 10-2: Item DEVELOPMENT SYSTEM PACKAGES Name System Description 1. PICMASTER System PICMASTER In-Circuit Emulator, PRO MATE Programmer, Assembler, Software Simulator, Samples and your choice of Target Probe. 2. PICSTART System PICSTART Low-Cost Prototype Programmer, Assembler, Software Simulator and Samples. 3. PRO MATE System PRO MATE Universal Programmer, full featured stand-alone or PC-hosted programmer, Assembler, Simulator 1995 Microchip Technology Inc. DS30081F-page 69 PIC16C8X NOTES: DS30081F-page 70 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 11.0 ELECTRICAL CHARACTERISTICS FOR PIC16C84 Absolute Maximum Ratings † Ambient temperature under bias.............................................................................................................-55°C to +125°C Storage temperature .............................................................................................................................. -65°C to +150°C Voltage on VDD with respect to VSS ............................................................................................................... 0 to +7.5V Voltage on MCLR with respect to VSS (Note 2).................................................................................................0 to +14V Voltage on all other pins with respect to VSS .................................................................................. -0.6V to (VDD + 0.6V) Total power dissipation (Note 1)...........................................................................................................................800 mW Maximum current out of VSS pin ...........................................................................................................................150 mA Maximum current into VDD pin ..............................................................................................................................100 mA Input clamp current, IIK (VI < 0 or VI > VDD) .....................................................................................................................± 20 mA Output clamp current, IOK (V0 < 0 or V0 >VDD) ...............................................................................................................± 20 mA Maximum output current sunk by any I/O pin..........................................................................................................25 mA Maximum output current sourced by any I/O pin ....................................................................................................20 mA Maximum current sunk by PORTA ..........................................................................................................................80 mA Maximum current sourced by PORTA .....................................................................................................................50 mA Maximum current sunk by PORTB........................................................................................................................150 mA Maximum current sourced by PORTB...................................................................................................................100 mA Note 1: Power dissipation is calculated as follows: Pdis = VDD x {IDD - ∑ IOH} + ∑ {(VDD-VOH) x IOH} + ∑(VOl x IOL) Note 2: Voltage spikes below VSS at the MCLR pin, inducing currents greater than 80 mA, may cause latch-up. Thus, a series resistor of 50-100Ω should be used when applying a “low” level to the MCLR pin rather than pulling this pin directly to VSS. † NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. TABLE 11-1: OSC RC XT HS CROSS REFERENCE OF DEVICE SPECS FOR OSCILLATOR CONFIGURATIONS AND FREQUENCIES OF OPERATION (COMMERCIAL DEVICES) PIC16C84-04 VDD: IDD: IPD: Freq: VDD: IDD: IPD: Freq: VDD: IDD: IPD: Freq: PIC16C84-10 4.0V to 6.0V 4.5 mA max. at 5.5V 100 µA max. at 4.0V WDT dis 4.0 MHz max. 4.0V to 6.0V 4.5 mA max. at 5.5V 100 µA max. at 4.0V WDT dis 4.0 MHz max. 4.5V to 5.5V 4.5 mA typ. at 5.5V 40.0 µA typ. at 4.5V WDT dis 4.0 MHz max. PIC16LC84-04 VDD: 4.5V to 5.5V IDD: 1.8 mA typ. at 5.5V IPD: 40.0 µA typ. at 4.5V WDT dis Freq: 4.0 MHz max. VDD: 4.5V to 5.5V IDD: 1.8 mA typ. at 5.5V IPD: 40.0 µA typ. at 4.5V WDT dis Freq: 4.0 MHz max. VDD: 4.5V to 5.5V IDD: 10 mA max. at 5.5V typ. IPD: 40.0 µA typ. at 4.5V WDT dis Freq: 10 MHz max. Do not use in LP mode LP VDD: 2.0V to 6.0V IDD: 4.5 mA typ. at 5.5V IPD: 100 µA typ. at 4V WDT dis Freq: 2.0 MHz max. VDD: 2.0V to 6.0V IDD: 4.5 mA typ. at 5.5V IPD: 100 µA typ. at 4V WDT dis Freq: 2.0 MHz max. Do not use in HS mode VDD: 2.0V to 6.0V VDD: 4.0V to 6.0V IDD: 60 µA typ. at 32 kHz, 2.0V IDD: 400 µA max. at 32 kHz, 2.0V IPD: 26 µA typ. at 2.0V WDT dis IPD: 100 µA max. at 4.0V WDT dis Freq: 200 kHz max. Freq: 200 kHz max. The shaded sections indicate oscillator selections which are tested for functionality, but not for MIN/MAX specifications. It is recommended that the user select the device type that ensures the specifications required. 1995 Microchip Technology Inc. DS30081F-page 71 Thi d t t d ith F M k 404 PIC16C8X Applicable Devices 83 R83 84 84A R84 11.1 DC CHARACTERISTICS: DC CHARACTERISTICS Parameter No. Sym D001 D001A D002 VDD D003 D004 D010 D010A VDR Characteristic Supply Voltage RAM Data Retention Voltage (Note 1) VPOR VDD start voltage to ensure Power-on Reset SVDD VDD rise rate to ensure Power-on Reset IDD Supply Current (Note 2) D013 PIC16C84-04 (Commercial, Industrial) PIC16C84-10 (Commercial, Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial and 0°C ≤ TA ≤ +70°C for commercial Min Typ† Max Units Conditions 4.0 4.5 1.5* — — — 6.0 5.5 — V V V XT, RC and LP osc configuration HS osc configuration Device in SLEEP mode — VSS — V See section on Power-on Reset for details 0.05* — — — — 1.8 7.3 4.5 10 mA mA — 5.0 10 mA V/ms See section on Power-on Reset for details RC and XT osc configuration (Note 4) FOSC = 4 MHz, VDD = 5.5V FOSC = 4 MHz, VDD = 5.5V (During EEPROM programming) HS osc configuration (PIC16C84-10) FOSC = 10 MHz, VDD = 5.5V VDD = 4.0V, WDT enabled, -40°C to +85°C VDD = 4.0V, WDT disabled, -0°C to +70°C VDD = 4.0V, WDT disabled, -40°C to +85°C D020 IPD Power-down Current — 40 100 µA D021 (Note 3) — 38 100 µA D021A — 38 100 µA * These parameters are characterized but not tested. † Data in "Typ" column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: This is the limit to which VDD can be lowered in SLEEP mode without losing RAM data. 2: The supply current is mainly a function of the operating voltage and frequency. Other factors such as I/O pin loading and switching rate, oscillator type, internal code execution pattern, and temperature also have an impact on current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1 = external square wave, from rail to rail; all I/O pins tristated, pulled to VDD, T0CKI = VDD, MCLR = VDD; WDT enabled/disabled as specified. 3: The power down current in SLEEP mode does not depend on the oscillator type. Power-down current is measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD or VSS. 4: For RC osc configuration, current through Rext is not included. The current through the resistor can be estimated by the formula IR = VDD/2Rext (mA) with Rext in kOhm. DS30081F-page 72 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 11.2 DC CHARACTERISTICS: DC CHARACTERISTICS Parameter No. Sym D001 D002 Supply Voltage RAM Data Retention Voltage (Note 1) VPOR VDD start voltage to ensure Power-on Reset SVDD VDD rise rate to ensure Power-on Reset Supply Current IDD (Note 2) D003 D004 D010 D010A Characteristic VDD VDR D014 PIC16LC84-04 (Commercial, Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial and 0°C ≤ TA ≤ +70°C for commercial Min Typ† Max Units Conditions 2.0 1.5 * — — 6.0 — V V XT, RC, and LP osc configuration Device in SLEEP mode — VSS — V See section on Power-on Reset for details 0.05* — — — — 1.8 7.3 4.5 10 mA mA — 60 400 µA V/ms See section on Power-on Reset for details RC and XT osc configuration (Note 4) FOSC = 2 MHz, VDD = 5.5V FOSC = 2 MHz, VDD = 5.5V (During EEPROM programming) LP osc configuration FOSC = 32 kHz, VDD = 2.0V WDT disabled VDD = 2.0V, WDT enabled, -40°C to +85°C VDD = 2.0V, WDT disabled, 0°C to +70°C VDD = 2.0V, WDT disabled, -40°C to +85°C IPD D020 Power-down Current — 26 100 µA D021 (Note 3) — 26 100 µA D021A — 26 100 µA * These parameters are characterized but not tested. † Data in "Typ" column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: This is the limit to which VDD can be lowered in SLEEP mode without losing RAM data. 2: The supply current is mainly a function of the operating voltage and frequency. Other factors such as I/O pin loading and switching rate, oscillator type, internal code execution pattern, and temperature also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1=external square wave, from rail to rail; all I/O pins tristated, pulled to VDD, T0CKI = VDD, MCLR = VDD; WDT enabled/disabled as specified. 3: The power down current in SLEEP mode does not depend on the oscillator type. Power-down current is measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD or VSS. 4: For RC osc configuration, current through Rext is not included. The current through the resistor can be estimated by the formula IR = VDD/2Rext (mA) with Rext in kOhm. 1995 Microchip Technology Inc. DS30081F-page 73 PIC16C8X Applicable Devices 83 R83 84 84A R84 11.3 DC CHARACTERISTICS: Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial and 0°C ≤ TA ≤ +70°C for commercial Operating voltage VDD range as described in DC spec Section 11-1 and Section 11-3. DC CHARACTERISTICS Parameter Sym No. VIL D030 D030A D031 D032 D033 D040 D040A D041 D042 D043 D050 D070 D060 PIC16C84-04 (Commercial, Industrial) PIC16C84-10 (Commercial, Industrial) PIC16LC84-04 (Commercial, Industrial) Characteristic Input Low Voltage I/O ports with TTL buffer Min VSS VSS VSS Vss with Schmitt Trigger buffer MCLR, RA4/T0CKI, OSC1 (RC mode) OSC1 (XT, HS and LP modes) Vss Input High Voltage VIH I/O ports with TTL buffer 0.36VDD 0.48VDD with Schmitt Trigger buffer 0.45VDD MCLR, RA4/T0CKI, OSC1 0.85VDD (RC mode) OSC1 (XT, HS and LP modes) 0.7VDD VHYS Hysteresis of TBD Schmitt Trigger inputs 50* IPURB PORTB weak pull-up current Input Leakage Current (Notes 2, 3) IIL I/O ports — D061 D063 MCLR, RA4/T0CKI OSC1/CLKIN — — Typ† Max Units Conditions — 0.8 — 0.16VDD — 0.2VDD — 0.2VDD V V V V 4.5 ≤ VDD ≤ 5.5V entire range (Note 4) entire range — 0.3VDD V Note1 — VDD V — — VDD VDD 4.5 ≤ VDD ≤ 5.5V entire range (Note 4) entire range V — VDD — — 250* 400* — ±1 — — ±5 ±5 V V Note1 µA VDD = 5V, VPIN = VSS µA Vss ≤ VPIN ≤ VDD, Pin at hi-impedance µA Vss ≤ VPIN ≤ VDD µA Vss ≤ VPIN ≤ VDD, XT, HS and LP osc configuration Output Low Voltage I/O ports — — 0.6 V IOL = 8.5 mA, VDD = 4.5V OSC2/CLKOUT — — 0.6 V IOL = 1.6 mA, VDD = 4.5V (RC osc configuration) Output High Voltage D090 VOH I/O ports (Note 3) VDD - 0.7 — — V IOH = -3.0 mA, VDD = 4.5V D093 OSC2/CLKOUT VDD - 0.7 — — V IOH = -1.3 mA, VDD = 4.5V (RC osc configuration) * These parameters are characterized but not tested. † Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: In RC oscillator configuration, the OSC1/CLKIN pin is a Schmitt Trigger input. It is not recommended that the PIC16C84 be driven with external clock in RC mode. 2: 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. 3: Negative current is defined as coming out of the pin. 4: The user may use better of the two specs. D080 D083 VOL DS30081F-page 74 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 11.4 DC CHARACTERISTICS: PIC16C84-04 (Commercial, Industrial) PIC16C84-10 (Commercial, Industrial) PIC16LC84-04 (Commercial, Industrial) DC CHARACTERISTICS Parameter No. Sym D100 COSC2 D101 CIO D120 D121 ED VDRW D122 TDEW D130 D131 EP VPR Characteristic Capacitive Loading Specs on Output Pins OSC2/CLKOUT pin All I/O pins and OSC2 (RC mode) Data EEPROM Memory Endurance VDD for read/write Erase/Write cycle time Program EEPROM Memory Endurance VDD for read Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial and 0°C ≤ TA ≤ +70°C for commercial Operating voltage VDD range as described in DC spec Section 11-1 and Section 11-3. Min Typ† Max Units Conditions — — 15 pF — — 50 pF 100,000 1,000,000 VMIN — — 6.0 — 10 — 100 VMIN — — — 6.0 In XT, HS and LP modes when external clock is used to drive OSC1. E/W V VMIN = Minimum operating voltage ms Note1 E/W V VMIN = Minimum operating voltage D132 VPEW VDD for erase/write 4.5 — 5.5 V D133 TPEW Erase/Write cycle time — 10 — ms Note1 † Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: The user should use interrupts or poll the EEIF or WR bits to ensure the write cycle has completed. 1995 Microchip Technology Inc. DS30081F-page 75 PIC16C8X Applicable Devices 83 R83 84 84A R84 TABLE 11-2: TIMING PARAMETER SYMBOLOGY The timing parameter symbols have been created following one of the following formats: 1. TppS2ppS 2. TppS T F Frequency Lowercase symbols (pp) and their meanings: pp ck CLKOUT io I/O port mc MCLR Uppercase symbols and their meanings: S F Fall H High I Invalid (Hi-impedance) L Low T Time osc t0 OSC1 T0CKI P R V Z Period Rise Valid Hi-impedance FIGURE 11-1: PARAMETER MEASUREMENT INFORMATION 0.7 VDD XTAL 0.8 VDD RC (High) 2.0 VDD (High) 0.3 VDD XTAL 0.15 VDD RC (Low) OSC1 Measurement Points 0.2 VDD (Low) I/O Port Measurement Points All timings are measured between high and low measurement points as indicated in the figure. FIGURE 11-2: LOAD CONDITIONS Load Condition 1 Load Condition 2 VDD/2 RL CL Pin CL Pin VSS VSS RL = 464Ω CL = 50 pF for all pins except OSC2. 15 pF for OSC2 output. DS30081F-page 76 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 11.5 Timing Diagrams and Specifications FIGURE 11-3: EXTERNAL CLOCK TIMING Q4 Q1 Q3 Q2 Q4 Q1 OSC1 1 3 3 4 4 2 CLKOUT TABLE 11-3: Parameter No. EXTERNAL CLOCK TIMING REQUIREMENTS Sym Characteristic Fos External CLKIN Frequency (Note 1) Min Typ† Max Units Conditions DC — 2 MHz XT, RC osc PIC16LC84-04 DC — 4 MHz XT, RC osc PIC16C84-04 DC — 10 MHz HS osc PIC16C84-10 DC — 200 kHz LP osc PIC16LC84-04 Oscillator Frequency DC — 2 MHz RC osc PIC16LC84-04 (Note 1) DC — 4 MHz RC osc PIC16C84-04 0.1 — 2 MHz XT osc PIC16LC84-04 0.1 — 4 MHz XT osc PIC16C84-04 1 — 10 MHz HS osc PIC16C84-10 DC — 200 kHz LP osc PIC16LC84-04 500 — — ns XT, RC osc PIC16LC84-04 1 TOSC External CLKIN Period (Note 1) 250 — — ns XT, RC osc PIC16C84-04 100 — — ns HS osc PIC16C84-10 5 — — µs LP osc PIC16LC84-04 Oscillator Period 500 — — ns RC osc PIC16LC84-04 (Note 1) 250 — — ns RC osc PIC16C84-04 500 — 10,000 ns XT osc PIC16LC84-04 250 — 10,000 ns XT osc PIC16C84-04 100 — 1,000 ns HS osc PIC16C84-10 5 — — µs LP osc PIC16LC84-04 0.4 4/Fosc DC µs 2 TCY Instruction Cycle Time (Note 1) 3 TosL, Clock in (OSC1) High or Low Time 60 * — — ns XT osc PIC16LC84-04 TosH 50 * — — ns XT osc PIC16C84-04 2* — — µs LP osc PIC16LC84-04 35 * — — ns HS osc PIC16C84-10 4 TosR, Clock in (OSC1) Rise or Fall Time 25 * — — ns XT osc PIC16C84-04 TosF 50 * — — ns LP osc PIC16LC84-04 15 * — — ns HS osc PIC16C84-10 † Data in "Typ" column is at 5.0V, 25˚C 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 pin. When an external clock input is used, the "Max." cycle time limit is "DC" (no clock) for all devices. 1995 Microchip Technology Inc. DS30081F-page 77 PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 11-4: CLKOUT AND I/O TIMING Q1 Q4 Q2 Q3 OSC1 11 10 22 23 CLKOUT 12 13 14 19 18 16 I/O Pin (input) 15 17 I/O Pin (output) new value old value 20, 21 Note: All tests must be done with specified capacitive loads (Figure 11-2) 50 pF on I/O pins and CLKOUT. TABLE 11-4: Parameter No. 10 CLKOUT AND I/O TIMING REQUIREMENTS Sym Characteristic TosH2ckL OSC1↑ to CLKOUT↓ 10A 11 TosH2ckH OSC1↑ to CLKOUT↑ 11A 12 TckR CLKOUT rise time 12A 13 TckF CLKOUT fall time 13A Min Typ† Max Units Conditions PIC16C84 — 15 30 * ns Note 1 PIC16LC84 — 15 120 * ns Note 1 PIC16C84 — 15 30 * ns Note 1 PIC16LC84 — 15 120 * ns Note 1 PIC16C84 — 15 30 * ns Note 1 PIC16LC84 — 15 100 * ns Note 1 PIC16C84 — 15 30 * ns Note 1 PIC16LC84 — 15 100 * ns Note 1 14 TckL2ioV CLKOUT ↓ to Port out valid — — 0.5TCY +20 * ns Note 1 15 TioV2ckH Port in valid before PIC16C84 0.30TCY + 30 * — — ns Note 1 CLKOUT ↑ PIC16LC84 0.30TCY + 80 * — — ns Note 1 16 TckH2ioI Port in hold after CLKOUT ↑ 0* — — ns Note 1 17 TosH2ioV OSC1↑ (Q1 cycle) to PIC16C84 — — 125 * ns Port out valid PIC16LC84 — — 250 * ns 18 TosH2ioI OSC1↑ (Q2 cycle) to Port input invalid (I/O in hold time) TBD — — ns 19 TioV2osH Port input valid to OSC1↑ (I/O in setup time) TBD — — ns 20 TioR Port output rise time 20A 21 TioF Port output fall time 21A 22 Tinp 22A 23 Trbp 23A PIC16C84 — 10 25 * ns PIC16LC84 — 10 60 * ns PIC16C84 — 10 25 * ns PIC16LC84 — 10 60 * ns INT pin high PIC16C84 20 * — — ns or low time PIC16LC84 55 * — — ns RB7:RB4 change INT PIC16C84 20 * — — ns high or low time PIC16LC84 55 * — — ns * † These parameters are characterized but not tested. Data in "Typ" column is at 5.0V, 25˚C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: Measurements are taken in RC Mode where CLKOUT output is 4 x TOSC. DS30081F-page 78 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 11-5: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP TIMER TIMING VDD MCLR 30 Internal POR 33 PWRT Time-out 32 OSC Time-out Internal RESET Watchdog Timer RESET 31 34 34 I/O Pins TABLE 11-5: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP TIMER REQUIREMENTS Parameter No. Sym Characteristic 30 TmcL MCLR Pulse Width (low) 31 Twdt Watchdog Timer Time-out Period (No Prescaler) 32 Tost Oscillation Start-up Timer Period 33 Tpwrt Power-up Timer Period 34 TIOZ I/O Hi-impedance from MCLR Low or reset * † Min Typ† Max Units Conditions 350 * 150 * — — — — ns ns 2.0V ≤ VDD ≤ 3.0V 3.0V ≤ VDD ≤ 6.0V 7* 18 33 * ms VDD = 5V — 1024TOSC — ms TOSC = OSC1 period 28 * 72 132 * ms VDD = 5.0V — — 100 * ns These parameters are characterized but not tested. Data in "Typ" column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. 1995 Microchip Technology Inc. DS30081F-page 79 PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 11-6: TIMER0 CLOCK TIMINGS RA4/T0CKI 40 41 42 TABLE 11-6: Parameter No. 40 TIMER0 CLOCK REQUIREMENTS Sym Characteristic Tt0H T0CKI High Pulse Width Min No Prescaler With Prescaler 41 Tt0L T0CKI Low Pulse Width No Prescaler With Prescaler 42 * † Tt0P T0CKI Period Typ† Max Units Conditions 0.5TCY + 20 * — — ns 50 * 30 * — — — — ns ns 0.5TCY + 20 * — — ns 50 * 20 * — — — — ns ns 2.0V ≤ VDD ≤ 3.0V 3.0V ≤ VDD ≤ 6.0V TCY + 40 * N — — ns N = prescale value (2, 4, ..., 256) 2.0V ≤ VDD ≤ 3.0V 3.0V ≤ VDD ≤ 6.0V These parameters are characterized but not tested. Data in "Typ" column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. DS30081F-page 80 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 12.0 DC & AC CHARACTERISTICS GRAPHS/TABLES FOR PIC16C84 The data graphs and tables provided in this section are for design guidance and are not tested or guaranteed. In some graphs or tables the data presented is outside specified operating range (e.g., outside specified VDD range). This is for information only and devices are guaranteed to operate properly only within the specified range. The data presented in this section is a statistical summary of data collected on units from different lots over a period of time. “Typical” represents the mean of the distribution while 'max' or 'Min' represents (mean + 3σ) and (mean - 3σ) respectively where σ is standard deviation. FIGURE 12-1: TYPICAL RC OSCILLATOR FREQUENCY vs. TEMPERATURE FOSC FOSC (25°C) Frequency Normalized To +25°C 1.10 Rext ≥ 10 kΩ Cext = 100 pF 1.08 1.06 1.04 1.02 1.00 VDD = 5.5V 0.98 0.96 0.94 VDD = 3.5V 0.92 0.90 0.88 0 10 20 25 30 40 50 60 70 T(°C) TABLE 12-1: RC OSCILLATOR FREQUENCIES * Cext Rext 20 pF 3.3k 5.1k 10k 100k 3.3k 5.1k 10k 100k 3.3k 5.1k 10k 100k 100 pF 300 pF Average Fosc @ 5V, 25°C 4.68 MHz 3.94 MHz 2.34 MHz 250.16 kHz 1.49 MHz 1.12 MHz 620.31 kHz 90.25 kHz 524.24 kHz 415.52 kHz 270.33 kHz 25.37 kHz ± 27% ± 25% ± 29% ± 33% ± 25% ± 25% ± 30% ± 26% ± 28% ± 30% ± 26% ± 25% *Measured in PDIP Packages.The percentage variation indicated here is part to part variation due to normal process distribution. The variation indicated is ±3 standard deviation from average value. 1995 Microchip Technology Inc. DS30081F-page 81 Thi d t t d ith F M k 404 PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 12-2: TYPICAL RC OSCILLATOR FREQUENCY vs. VDD 5.5 5.0 R = 3.3k 4.5 4.0 R = 5k FOSC (MHz) 3.5 3.0 Cext = 20 pF, T = 25°C 2.5 2.0 R = 10k 1.5 1.0 R = 100k 0.5 0.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 VDD (Volts) DS30081F-page 82 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 12-3: TYPICAL RC OSCILLATOR FREQUENCY vs. VDD 2.2 2.0 1.8 R = 3.3k 1.6 FOSC (MHz) 1.4 R = 5k 1.2 1.0 0.8 R = 10k 0.6 Cext =100 pF, T = 25°C 0.4 R = 100k 0.2 0.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 5.5 6.0 VDD (Volts) FIGURE 12-4: TYPICAL RC OSCILLATOR FREQUENCY vs. VDD 1.1 1.0 0.9 0.8 Cext = 300 pF, T = 25°C FOSC (MHz) 0.7 R = 3.3k 0.6 0.5 R = 5k 0.4 0.3 R = 10k 0.2 0.1 R = 100k 0.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 VDD (Volts) 1995 Microchip Technology Inc. DS30081F-page 83 PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 12-5: TYPICAL IPD vs. VDD WATCHDOG DISABLED (25˚C) 60 50 IPD (µA) 40 30 20 10 0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 5.0 5.5 6.0 VDD (Volts) FIGURE 12-6: TYPICAL IPD vs. VDD WATCHDOG ENABLED (25˚C) 60 50 IPD(µA) 40 30 20 10 0 2.0 2.5 3.0 3.5 4.0 4.5 VDD (Volts) DS30081F-page 84 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 12-7: MAXIMUM IPD vs. VDD WATCHDOG DISABLED 120 100 5°C p. = 8 em Max. T IPD(µA) 80 25°C mp. = e T . p Ty 60 0°C p. = -4 em Min. T 40 20 0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 5.0 5.5 6.0 VDD (Volts) FIGURE 12-8: MAXIMUM IPD vs. VDD WATCHDOG ENABLED* 120 100 emp. Max. T IPD(µA) 80 = 85°C mp. = e Typ. T 25°C 60 0°C p. = -4 m e T . Min 40 20 0 2.0 2.5 3.0 3.5 4.0 4.5 VDD (Volts) * IPD, with Watchdog Timer enabled, has two components: The leakage current which increases with higher temperature and the operating current of the Watchdog Timer logic which increases with lower temperature. At -40°C, the latter dominates explaining the apparently anomalous behavior. 1995 Microchip Technology Inc. DS30081F-page 85 PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 12-9: VTH (INPUT THRESHOLD VOLTAGE) OF I/O PINS vs. VDD 2.0 1.8 Max (-40°C to +85°C) VTH(Volts) 1.6 Typ @ 25°C 1.4 1.2 Min (-40°C to +85°C) 1.0 0.8 0.6 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 VDD (Volts) FIGURE 12-10: VTH (INPUT THRESHOLD VOLTAGE) OF OSC1 INPUT (IN XT, HS, AND LP MODES) vs. VDD 3.4 3.2 3.0 C) 85° + to VTH (Volts) 2.8 C 40° 2.6 (ax M 2.4 Typ 2.2 °C -40 °C) (25 C) 85° + to ( Min 2.0 1.8 1.6 1.4 1.2 1.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 VDD (Volts) DS30081F-page 86 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 12-11: VIH, VIL OF MCLR, T0CKI and OSC1 (IN RC MODE) vs. VDD 5.0 VIH, max (-40°C to +85°C) 4.5 VIH, typ (25°C) 4.0 VIH, min (-40°C to +85°C) VIH, VIL(volts) 3.5 3.0 VIL, max (-40°C to +85°C) 2.5 VIL, typ (25°C) VIL, min (-40°C to +85°C) 2.0 1.5 1.0 0.5 0.0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 VDD (Volts) 1995 Microchip Technology Inc. DS30081F-page 87 PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 12-12: TYPICAL IDD vs. FREQ (EXT CLOCK, 25˚C) 10,000 IDD (µA) 1,000 100 6.0V 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V 10 10k 100k 1M 10M 100M 10M 100M External Clock Frequency (Hz) FIGURE 12-13: MAXIMUM IDD vs. FREQ (EXT CLOCK, -40˚ TO +85˚C) 10,000 IDD (µA) 1,000 100 6.0V 5.5V 5.0V 4.5V 4.0V 3.5V 3.0V 2.5V 2.0V 10 10k 100k 1M External Clock Frequency (Hz) DS30081F-page 88 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 12-14: WDT TIMER TIME-OUT PERIOD vs. VDD 70 60 WDT Period (ms) Max. 85°C 50 Max. 70°C 40 Typ. 25°C 30 Min. 0°C 20 Min. -40°C 10 0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 VDD (Volts) FIGURE 12-15: TRANSCONDUCTANCE (gm) OF HS OSCILLATOR vs. VDD 10000 9000 8000 7000 gm(µA/V) 6000 5000 Max @ -40°C 4000 Typ @ 25°C 3000 Min @ 85°C 2000 1000 0 2.0 3.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (Volts) 1995 Microchip Technology Inc. DS30081F-page 89 PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 12-16: TRANSCONDUCTANCE (gm) OF LP OSCILLATOR vs. VDD 250 225 200 175 Typ @ 25°C Max @ -40°C gm(µA/V) 150 125 Min @ 85°C 100 75 50 25 0 2.0 2.5 3.0 3.5 4.0 5.0 4.5 5.5 VDD (Volts) FIGURE 12-17: TRANSCONDUCTANCE (gm) OF XT OSCILLATOR vs. VDD 2000 1800 1600 Max @ -40°C 1400 Typ @ 25°C gm(µA/V) 1200 1000 Min @ 85°C 800 600 400 200 0 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 VDD (Volts) DS30081F-page 90 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 12-18: IOH vs. VOH, VDD = 3V 0 -2 IOH (mA) -4 -6 Min @ 85°C -8 -10 -12 Typ @ 25°C -14 Max @ -40°C -16 -18 0.0 0.5 1.0 1.5 2.0 3.0 2.5 VDD (Volts) FIGURE 12-19: IOH vs. VOH, VDD = 5V 0 -5 -10 Min @ 85°C -15 -20 IOH (mA) Max @ -40°C -25 Typ @ 25°C -30 -35 -40 -45 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 VDD (Volts) 1995 Microchip Technology Inc. DS30081F-page 91 PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 12-20: IOL vs. VOL, VDD = 3V 35 Max. -40°C 30 Typ. 25°C IOL (mA) 25 20 Min. +85°C 15 10 5 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 VDD (Volts) FIGURE 12-21: IOL vs. VOL, VDD = 5V 90 80 Max @ -40°C IOL (mA) 70 60 Typ @ 25°C 50 40 Min @ +85°C 30 20 10 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 VDD (Volts) DS30081F-page 92 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 TABLE 12-2: INPUT CAPACITANCE * Typical Capacitance (pF) Pin Name 18L PDIP 18L SOIC PORTA 5.0 4.3 PORTB 5.0 4.3 MCLR 17.0 17.0 OSC1/CLKIN 4.0 3.5 OSC2/CLKOUT 4.3 3.5 T0CKI 3.2 2.8 * All capacitance values are typical at 25°C. A part to part variation of ±25% (three standard deviations) should be taken into account. 1995 Microchip Technology Inc. DS30081F-page 93 PIC16C8X Applicable Devices 83 R83 84 84A R84 NOTES: DS30081F-page 94 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 13.0 ELECTRICAL CHARACTERISTICS FOR PIC16C83, PIC16CR83, PIC16C84A AND PIC16CR84 Absolute Maximum Ratings † Ambient temperature under bias.............................................................................................................-55°C to +125°C Storage temperature .............................................................................................................................. -65°C to +150°C Voltage on any pin with respect to VSS (except VDD and MCLR).................................................... -0.6V to (VDD + 0.6V) Voltage on VDD with respect to VSS ............................................................................................................... 0 to +7.5V Voltage on MCLR with respect to VSS (Note 2).................................................................................................0 to +14V Total power dissipation (Note 1)...........................................................................................................................800 mW Maximum current out of VSS pin ...........................................................................................................................150 mA Maximum current into VDD pin ..............................................................................................................................100 mA Input clamp current, IIK (VI < 0 or VI > VDD) .....................................................................................................................± 20 mA Output clamp current, IOK (V0 < 0 or V0 > VDD) ..............................................................................................................± 20 mA Maximum output current sunk by any I/O pin..........................................................................................................25 mA Maximum output current sourced by any I/O pin ....................................................................................................20 mA Maximum current sunk by PORTA ..........................................................................................................................80 mA Maximum current sourced by PORTA .....................................................................................................................50 mA Maximum current sunk by PORTB........................................................................................................................150 mA Maximum current sourced by PORTB...................................................................................................................100 mA Note 1: Power dissipation is calculated as follows: Pdis = VDD x {IDD - ∑ IOH} + ∑ {(VDD-VOH) x IOH} + ∑(VOl x IOL) Note 2: Voltage spikes below VSS at the MCLR pin, inducing currents greater than 80 mA, may cause latch-up. Thus, a series resistor of 50-100Ω should be used when applying a “low” level to the MCLR pin rather than pulling this pin directly to VSS. † NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. Preliminary 1995 Microchip Technology Inc. Thi d t t d ith F DS30081F-page 95 M k 404 PIC16C8X Applicable Devices 83 R83 84 84A R84 TABLE 13-1: CROSS REFERENCE OF DEVICE SPECS FOR OSCILLATOR CONFIGURATIONS AND FREQUENCIES OF OPERATION (COMMERCIAL DEVICES) OSC PIC16LC84A-04 PIC16LCR84-94 PIC16LC83-04 PIC16LCR83-04 PIC16C84A-10 PIC16CR84-10 PIC16C83-10 PIC16CR83-10 PIC16C84A-04 PIC16CR84-04 PIC16C83-04 PIC16CR83-04 RC VDD: IDD: IPD: Freq: 4.0V to 6.0V 4.5 mA max. at 5.5V 14 µA max. at 4V WDT dis 4.0 MHz max. VDD: IDD: IPD: Freq: 4.5V to 5.5V 1.8 mA typ. at 5.5V 1.0 µA typ. at 5.5V WDT dis 4..0 MHz max. VDD: IDD: IPD: Freq: XT VDD: IDD: IPD: Freq: VDD: 4.0V to 6.0V 4.5 mA max. at 5.5V 14 µA max. at 4V WDT dis 4.0 MHz max. 4.5V to 5.5V VDD: IDD: IPD: Freq: VDD: 4.5V to 5.5V 1.8 mA typ. at 5.5V 1.0 µA typ. at 5.5V WDT dis 4.0 MHz max. 4.5V to 5.5V VDD: 2.0V to 6.0V IDD: 4.5 mA max. at 5.5V IPD: 7.0 µA max. at 2V WDT dis Freq: 2.0 MHz max. Do not use in HS mode IDD: IPD: Freq: VDD: IDD: IPD: Freq: 4.5 mA typ. at 5.5V 1.0 µA typ. at 4.5V WDT dis HS LP 4.0 MHz max. 4.0V to 6.0V 35 µA typ. at 32 kHz, 3.0V 0.6 µA typ. at 3.0V WDT dis 200 kHz max. 2.0V to 6.0V 4.5 mA max. at 5.5V 7.0 µA max. at 2V WDT dis 2.0 MHz max. IDD: 10 mA max. at 5.5V typ. IPD: 1.0 µA typ. at 4.5V WDT dis Freq: 10 MHz max. Do not use in LP mode VDD: IDD: IPD: Freq: 2.0V to 6.0V 32 µA max. at 32 kHz, 3.0V 7 µA max. at 2.0V WDT dis 200 kHz max. The shaded sections indicate oscillator selections which are tested for functionality, but not for MIN/MAX specifications. It is recommended that the user select the device type that ensures the specifications required. DS30081F-page 96 Preliminary 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 13.1 DC CHARACTERISTICS: DC CHARACTERISTICS Parameter No. Sym Characteristic D001 D001A D002 VDD Supply Voltage VDR D003 VPOR D004 SVDD RAM Data Retention Voltage (Note 1) VDD start voltage to ensure Power-on Reset VDD rise rate to ensure Power-on Reset Supply Current (Note 2) IDD D010 D010A PIC16C84A, PIC16C83 (Commercial, Industrial) PIC16CR84, PIC16CR83 (Commercial, Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial and 0°C ≤ TA ≤ +70°C for commercial Min Typ† Max Units Conditions 4.0 4.5 1.5 * — — 6.0 5.5 — V V V XT, RC and LP osc configuration HS osc configuration Device in SLEEP mode — — VSS — V See section on Power-on Reset for details 0.05* — — — — 1.8 7.3 4.5 10 V/ms See section on Power-on Reset for details mA mA RC and XT osc configuration (Note 4) FOSC = 4.0 MHz, VDD = 5.5V FOSC = 4.0 MHz, VDD = 5.5V (During EEPROM programming) HS OSC CONFIGURATION (PIC16C84-10) FOSC = 10 MHz, VDD = 5.5V VDD = 4.0V, WDT enabled, -40°C to +85°C VDD = 4.0V, WDT disabled, -0°C to +70°C VDD = 4.0V, WDT disabled, -40°C to +85°C — D013 5 10 mA D020 IPD Power-down Current — 7.0 28 µA D021 (Note 3) 1.0 14 µA — D021A 1.0 16 µA — * These parameters are characterized but not tested. † Data in "Typ" column is at 5.0V, 25˚C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: This is the limit to which VDD can be lowered in SLEEP mode without losing RAM data. 2: The supply current is mainly a function of the operating voltage and frequency. Other factors such as I/O pin loading and switching rate, oscillator type, internal code execution pattern, and temperature also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1=external square wave, from rail to rail; all I/O pins tristated, pulled to VDD, T0CKI = VDD, MCLR = VDD; WDT enabled/disabled as specified. 3: The power down current in SLEEP mode does not depend on the oscillator type. Power-down current is measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD and VSS. 4: For RC osc configuration, current through Rext is not included. The current through the resistor can be estimated by the formula IR = VDD/2Rext (mA) with Rext in kOhm. 1995 Microchip Technology Inc. Preliminary DS30081F-page 97 PIC16C8X Applicable Devices 83 R83 84 84A R84 13.2 DC CHARACTERISTICS: DC CHARACTERISTICS Parameter No. Sym D001 D002 VDD VDR D003 VPOR D004 SVDD IDD D010 D010A D014 Characteristic Supply Voltage RAM Data Retention Voltage (Note 1) VDD start voltage to ensure Power-on Reset VDD rise rate to ensure Power-on Reset Supply Current (Note 2) PIC16LC84A, PIC16LC83 (Commercial, Industrial) PIC16LCR84, PIC16LCR83 (Commercial, Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial and 0°C ≤ TA ≤ +70°C for commercial Min Typ† Max Units Conditions 2.0 1.5 * — — 6.0 — V V XT, RC, and LP osc configuration Device in SLEEP mode — VSS — V See section on Power-on Reset for details 0.05* — — — — 1.8 7.3 4.5 10 mA mA — 15 32 µA V/ms See section on Power-on Reset for details RC and XT osc configuration (Note 4) FOSC = 2.0 MHz, VDD = 5.5V FOSC = 2.0 MHz, VDD = 5.5V (During EEPROM programming) LP osc configuration FOSC = 32 kHz, VDD = 2.0V, WDT disabled VDD = 2.0V, WDT enabled, -40°C to +85°C VDD = 2.0V, WDT disabled, 0°C to +70°C VDD = 2.0V, WDT disabled, -40°C to +85°C IPD D020 Power-down Current — 3.0 16 µA D021 (Note 3) — 0.4 7.0 µA D021A — 0.4 9.0 µA * These parameters are characterized but not tested. † Data in "Typ" column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: This is the limit to which VDD can be lowered in SLEEP mode without losing RAM data. 2: The supply current is mainly a function of the operating voltage and frequency. Other factors such as I/O pin loading and switching rate, oscillator type, internal code execution pattern, and temperature also have an impact on the current consumption. The test conditions for all IDD measurements in active operation mode are: OSC1=external square wave, from rail to rail; all I/O pins tristated, pulled to VDD, T0CKI = VDD, MCLR = VDD; WDT enabled/disabled as specified. 3: The power down current in SLEEP mode does not depend on the oscillator type. Power-down current is measured with the part in SLEEP mode, with all I/O pins in hi-impedance state and tied to VDD and VSS. 4: For RC osc configuration, current through Rext is not included. The current through the resistor can be estimated by the formula IR = VDD/2Rext (mA) with Rext in kOhm. DS30081F-page 98 Preliminary 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 13.3 DC CHARACTERISTICS: PIC16C84A, PIC16C83 (Commercial, Industrial) PIC16CR84A, PIC16CR83 (Commercial, Industrial) PIC16LC84A, PIC16LC83 (Commercial, Industrial) PIC16LCR84, PIC16LCR83 (Commercial, Industrial) Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial and 0°C ≤ TA ≤ +70°C for commercial Operating voltage VDD range as described in DC spec Section 13-1 and Section 13-3 DC CHARACTERISTICS Parameter No. Sym VIL D030 D030A D031 D032 D033 D034 VIH D040 D040A D041 D042 D043 D050 VHYS D070 IPURB D060 IIL D061 D063 Characteristic Input Low Voltage I/O ports with TTL buffer with Schmitt Trigger buffer MCLR, RA4/T0CKI OSC1 (XT, HS and LP modes) OSC1 (RC mode) Input High Voltage I/O ports with TTL buffer Min Typ† Max Units VSS VSS VSS Vss Vss Vss — — — — — — 0.8 0.16VDD 0.2VDD 0.2VDD 0.3VDD 0.1VDD V V V V V V 4.5 V ≤ Vdd ≤ 5.5 V entire range (Note 4) entire range VDD VDD VDD VDD V V 4.5 V ≤ VDD ≤ 5.5V entire range (Note 4) entire range VDD V V Note1 — — 2.4 — 0.48VDD with Schmitt Trigger buffer 0.45VDD — MCLR, RA4/T0CKI, OSC1 0.85 VDD — (RC mode) — OSC1 (XT, HS and LP modes) 0.7 VDD Hysteresis of TBD — Schmitt Trigger inputs PORTB weak pull-up current 50* 250* Input Leakage Current (Notes 2, 3) I/O ports — — MCLR, RA4/T0CKI OSC1 Conditions — — — — — 400* ±1 ±5 ±5 V Note1 µA VDD = 5.0V, VPIN = VSS µA Vss ≤ VPIN ≤ VDD, Pin at hi-impedance µA Vss ≤ VPIN ≤ VDD µA Vss ≤ VPIN ≤ VDD, XT, HS and LP osc configuration Output Low Voltage I/O ports — — 0.6 V IOL = 8.5 mA, VDD = 4.5V OSC2/CLKOUT — — 0.6 V IOL = 1.6 mA, VDD = 4.5V Output High Voltage D090 VOH I/O ports (Note 3) VDD-0.7 — — V IOH = -3.0 mA, VDD = 4.5V D092 OSC2/CLKOUT VDD-0.7 — — V IOH = -1.3 mA, VDD = 4.5V * These parameters are characterized but not tested. † Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. Note 1: In RC oscillator configuration, the OSC1 pin is a Schmitt Trigger input. Do not drive the PIC16C8X with an external clock while the device is in RC mode, otherwise chip damage may result. 2: 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. 3: Negative current is defined as coming out of the pin. 4: The user may use better of the two specs. D080 D083 VOL 1995 Microchip Technology Inc. Preliminary DS30081F-page 99 PIC16C8X Applicable Devices 83 R83 84 84A R84 13.4 DC CHARACTERISTICS: PIC16C84A, PIC16C83 (Commercial, Industrial) PIC16CR84A, PIC16CR83 (Commercial, Industrial) PIC16LC84A, PIC16C83 (Commercial, Industrial) PIC16LCR84A, PIC16LCR83 (Commercial, Industrial) DC CHARACTERISTICS Parameter No. Sym D100 COSC2 D101 CIO D120 D121 ED VDRW D122 TDEW D130 D131 EP VPR Characteristic Capacitive Loading Specs on Output Pins OSC2 pin All I/O pins and OSC2 (RC mode) Data EEPROM Memory Endurance VDD for read/write Erase/Write cycle time Program EEPROM Memory Endurance VDD for read Standard Operating Conditions (unless otherwise stated) Operating temperature -40°C ≤ TA ≤ +85°C for industrial and 0°C ≤ TA ≤ +70°C for commercial Operating voltage VDD range as described in DC spec Section 13-1 and Section 13-3 Min Typ† Max Units Conditions — — 15 pF — — 50 pF 100,000 1,000,000 VMIN — — 6.0 10 — — 100 VMIN 1000 — — 6.0 In XT, HS and LP modes when external clock is used to drive OSC1. E/W V VMIN = Minimum operating voltage ms E/W V VMIN = Minimum operating voltage D132 VPEW VDD for erase/write 4.5 — 5.5 V D133 TPEW Erase/Write cycle time — 10 — ms † Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. DS30081F-page 100 Preliminary 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 TABLE 13-2: TIMING PARAMETER SYMBOLOGY The timing parameter symbols have been created following one of the following formats: 1. TppS2ppS 2. TppS T F Frequency Lowercase symbols (pp) and their meanings: pp ck CLKOUT io I/O port mc MCLR Uppercase symbols and their meanings: S F Fall H High I Invalid (Hi-impedance) L Low T Time osc t0 OSC1 T0CKI P R V Z Period Rise Valid High Impedance FIGURE 13-1: PARAMETER MEASUREMENT INFORMATION All timings are measure between high and low measurement points as indicated in the figures below. 0.7 VDD XTAL 0.8 VDD RC (High) 0.9 VDD (High) 0.3 VDD XTAL 0.15 VDD RC (Low) OSC1 Measurement Points 0.1 VDD (Low) I/O Port Measurement Points FIGURE 13-2: LOAD CONDITIONS Load Condition 1 Load Condition 2 VDD/2 RL VSS CL Pin CL Pin VSS RL = CL = 464Ω 50 pF for all pins except OSC2. 15 pF for OSC2 output. 1995 Microchip Technology Inc. Preliminary DS30081F-page 101 PIC16C8X Applicable Devices 83 R83 84 84A R84 13.5 Timing Diagrams and Specifications for PIC16C83, PIC16CR83, PIC16C84A, and PIC16CR84 FIGURE 13-3: EXTERNAL CLOCK TIMING Q4 Q1 Q3 Q2 Q4 Q1 OSC1 1 3 3 4 4 2 CLKOUT TABLE 13-3: Parameter No. EXTERNAL CLOCK TIMING REQUIREMENTS Sym Characteristic Min Typ† Max Fos External CLKIN Frequency (Note 1) DC — 2 MHz XT, RC osc DC — 4 MHz XT, RC osc DC — 10 MHz HS osc DC — 200 kHz LP osc DC — 2 MHz RC osc DC — 4 MHz RC osc 0.1 — 2 MHz XT osc 0.1 — 4 MHz XT osc 1.0 — 10 MHz HS osc DC — 200 kHz LP osc Oscillator Frequency (Note 1) Units Conditions PIC16LC8X-04 PIC16LCR8X-04 PIC16C8X-04 PIC16CR8X-04 PIC16C8X-10 PIC16CR8X-10 PIC16LC8X-04 PIC16LCR8X-04 PIC16LC8X-04 PIC16LCR8X-04 PIC16C8X-04 PIC16CR8X-04 PIC16LC8X-04 PIC16LCR8X-04 PIC16C8X-04 PIC16CR8X-04 PIC16C8X-10 PIC16CR8X-10 PIC16LC8X-04 PIC16LCR8X-04 † Data in "Typ" column is at 5.0V, 25°C 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 pin. When an external clock input is used, the "Max." cycle time limit is "DC" (no clock) for all devices. DS30081F-page 102 Preliminary 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 TABLE 13-3: EXTERNAL CLOCK TIMING REQUIREMENTS (CONTINUED) Parameter No. Sym Characteristic Min Typ† Max 1 TOSC External CLKIN Period (Note 1) 500 — — ns XT, RC osc 250 — — ns XT, RC osc 100 — — ns HS osc 5.0 — — µs LP osc 500 — — ns RC osc 250 — — ns RC osc 500 — 10,000 ns XT osc 250 — 10,000 ns XT osc 100 — 1,000 ns HS osc 5.0 — — µs LP osc 0.4 60 * 4/Fosc — DC — µs ns XT osc 50 * — — ns XT osc 2.0 * — — µs LP osc 35 * — — ns HS osc 25 * — — ns XT osc 50 * — — ns LP osc 15 * — — ns HS osc Oscillator Period (Note 1) 2 3 4 TCY TosL, TosH TosR, TosF Instruction Cycle Time (Note 1) Clock in (OSC1) High or Low Time Clock in (OSC1) Rise or Fall Time Units Conditions PIC16LC8X-04 PIC16LCR8X-04 PIC16C8X-04 PIC16CR8X-04 PIC16C8X-10 PIC16CR8X-10 PIC16LC8X-04 PIC16LCR8X-04 PIC16LC8X-04 PIC16LCR8X-04 PIC16C8X-04 PIC16CR8X-04 PIC16LC8X-04 PIC16LCR8X-04 PIC16C8X-04 PIC16CR8X-04 PIC16C8X-10 PIC16CR8X-10 PIC16LC8X-04 PIC16LCR8X-04 PIC16LC8X-04 PIC16LCR8X-04 PIC16C8X-04 PIC16CR8X-04 PIC16LC8X-04 PIC16LCR8X-04 PIC16C8X-10 PIC16CR8X-10 PIC16C8X-04 PIC16CR8X-04 PIC16LC8X-04 PIC16LCR8X-04 PIC16C8X-10 PIC16CR8X-10 † Data in "Typ" column is at 5.0V, 25°C 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 pin. When an external clock input is used, the "Max." cycle time limit is "DC" (no clock) for all devices. 1995 Microchip Technology Inc. Preliminary DS30081F-page 103 PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 13-4: CLKOUT AND I/O TIMING Q1 Q4 Q2 Q3 OSC1 11 10 22 23 CLKOUT 13 12 19 18 14 16 I/O Pin (input) 15 17 I/O Pin (output) new value old value 20, 21 Note: All tests must be done with specified capacitive loads (Figure 13-2) 50 pF on I/O pins and CLKOUT. TABLE 13-4: Parameter No. 10 CLKOUT AND I/O TIMING REQUIREMENTS Sym Characteristic TosH2ckL OSC1↑ to CLKOUT↓ TosH2ckH OSC1↑ to CLKOUT↑ 10A 11 11A 12 TckR CLKOUT rise time TckF CLKOUT fall time 12A 13 13A 14 TckL2ioV 15 TioV2ckH Min Typ† Max PIC16C8X — 15 30 * ns Note 1 PIC16LC8X — 15 120 * ns Note 1 PIC16C8X — 15 30 * ns Note 1 PIC16LC8X — 15 120 * ns Note 1 PIC16C8X — 15 30 * ns Note 1 PIC16LC8X — 15 100 * ns Note 1 PIC16C8X — 15 30 * ns Note 1 PIC16LC8X — 15 100 * ns Note 1 — — 0.5TCY +20 * ns Note 1 CLKOUT ↓ to Port out valid Units Conditions Port in valid before PIC16C8X 0.30TCY + 30 * — — ns Note 1 CLKOUT ↑ PIC16LC8X 0.30TCY + 80 * — — ns Note 1 Note 1 16 TckH2ioI Port in hold after CLKOUT ↑ 0* — — ns 17 TosH2ioV OSC1↑ (Q1 cycle) to PIC16C8X — — 125 * ns Port out valid PIC16LC8X — — 250 * ns 18 TosH2ioI OSC1↑ (Q2 cycle) to Port input invalid (I/O in hold time) TBD — — ns 19 TioV2osH Port input valid to OSC1↑ (I/O in setup time) TBD — — ns 20 TioR Port output rise time PIC16C8X — 10 25 * ns PIC16LC8X — 10 60 * ns TioF Port output fall time PIC16C8X — 10 25 * ns PIC16LC8X — 10 60 * ns INT pin high PIC16C8X 20 * — — ns or low time PIC16LC8X 55 * — — ns RB7:RB4 change INT PIC16C8X TOSC § — — ns high or low time PIC16LC8X TOSC § — — ns 20A 21 21A 22 Tinp 22A 23 Trbp 23A * † These parameters are characterized but not tested. Data in "Typ" column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. § By design Note 1: Measurements are taken in RC Mode where CLKOUT output is 4 x TOSC. DS30081F-page 104 Preliminary 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 13-5: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP TIMER TIMING VDD MCLR 30 Internal POR 33 PWRT Time-out 32 OSC Time-out Internal RESET Watchdog Timer RESET 31 34 34 I/O Pins TABLE 13-5: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND POWER-UP TIMER REQUIREMENTS Parameter No. Sym Characteristic 30 TmcL MCLR Pulse Width (low) 31 Twdt Watchdog Timer Time-out Period (No Prescaler) 32 Tost Oscillation Start-up Timer Period 33 Tpwrt 34 TIOZ * † Power-up Timer Period I/O Hi-impedance from MCLR Low or reset Min Typ† Max Units 1000 * — — ns 2.0V ≤ VDD ≤ 6.0V 7* 18 33 * ms VDD = 5.0V ms TOSC = OSC1 period VDD = 5.0V 1024TOSC 28 * 72 132 * ms — — 100 * ns Conditions These parameters are characterized but not tested. Data in "Typ" column is at 5V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. 1995 Microchip Technology Inc. Preliminary DS30081F-page 105 PIC16C8X Applicable Devices 83 R83 84 84A R84 FIGURE 13-6: TIMER0 CLOCK TIMINGS RA4/T0CKI 40 41 42 TABLE 13-6: Parameter No. 40 TIMER0 CLOCK REQUIREMENTS Sym Characteristic Tt0H T0CKI High Pulse Width Min No Prescaler With Prescaler 41 Tt0L T0CKI Low Pulse Width No Prescaler With Prescaler 42 * † Tt0P T0CKI Period Typ† Max Units Conditions 0.5TCY + 20 * — — ns 50 * 30 * — — — — ns ns 0.5TCY + 20 * — — ns 50 * 20 * — — — — ns ns 2.0V ≤ VDD ≤ 3.0V 3.0V ≤ VDD ≤ 6.0V TCY + 40 * N — — ns N = prescale value (2, 4, ..., 256) 2.0V ≤ VDD ≤ 3.0V 3.0V ≤ VDD ≤ 6.0V These parameters are characterized but not tested. Data in "Typ" column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance only and are not tested. DS30081F-page 106 Preliminary 1995 Microchip Technology Inc. PIC16C8X Applicable Devices 83 R83 84 84A R84 14.0 DC & AC CHARACTERISTICS GRAPHS/TABLES FOR PIC16C83, PIC16CR83, PIC16C84A, AND PIC16CR84 Device Characteristics Not Available at This Time 1995 Microchip Technology Inc. DS30081F-page 107 Thi d t t d ith F M k 404 PIC16C8X Applicable Devices 83 R83 84 84A R84 TABLE 14-1: INPUT CAPACITANCE * Typical Capacitance (pF) Pin Name 18L PDIP 18L SOIC PORTA 5.0 4.3 PORTB 5.0 4.3 MCLR 17.0 17.0 OSC1/CLKIN 4.0 3.5 OSC2/CLKOUT 4.3 3.5 T0CKI 3.2 2.8 * All capacitance values are typical at 25°C. A part to part variation of ±25% (three standard deviations) should be taken into account. DS30081F-page 108 1995 Microchip Technology Inc. PIC16C8X 15.0 PACKAGING INFORMATION 15.1 18-Lead Plastic Dual In-line (300 mil) N α C E1 E eA eB Pin No. 1 Indicator Area D S S1 Base Plane Seating Plane L B1 A1 A2 A e1 B D1 Package Group: Plastic Dual In-Line (PLA) Millimeters Max Inches Symbol Min Notes α 0° 10° 0° 10° A A1 A2 B B1 C D D1 E E1 e1 eA eB L N S S1 – 0.381 3.048 0.355 1.524 0.203 22.479 20.320 7.620 6.096 2.489 7.620 7.874 3.048 18 0.889 0.127 4.064 – 3.810 0.559 1.524 0.381 23.495 20.320 8.255 7.112 2.591 7.620 9.906 3.556 18 – – – 0.015 0.120 0.014 0.060 0.008 0.885 0.800 0.300 0.240 0.098 0.300 0.310 0.120 18 0.035 0.005 0.160 – 0.150 0.022 0.060 0.015 0.925 0.800 0.325 0.280 0.102 0.300 0.390 0.140 18 – – Reference Typical Reference Typical Reference Min 1995 Microchip Technology Inc. Max Notes Reference Typical Reference Typical Reference DS30081F-page 109 Thi d t t d ith F M k 404 PIC16C8X 15.2 18-Lead Plastic Surface Mount (SOIC - Wide, 300 mil Body) e B h x 45° N Index Area E H α C Chamfer h x 45° L 1 2 3 D Seating Plane Base Plane CP A1 A Package Group: Plastic SOIC (SO) Millimeters Symbol Min Max Inches Notes Min Max α 0° 8° 0° 8° A A1 B C D E e H h L N CP 2.362 0.101 0.355 0.241 11.353 7.416 1.270 10.007 0.381 0.406 18 – 2.642 0.300 0.483 0.318 11.735 7.595 1.270 10.643 0.762 1.143 18 0.102 0.093 0.004 0.014 0.009 0.447 0.292 0.050 0.394 0.015 0.016 18 – 0.104 0.012 0.019 0.013 0.462 0.299 0.050 0.419 0.030 0.045 18 0.004 DS30081F-page 110 Reference Notes Reference 1995 Microchip Technology Inc. PIC16C8X 15.3 Package Marking Information Example 18L PDIP MMMMMMMMMMMMXXX MMMMMMMMXXXXXXXX PIC16C84 10I/P 9305 CBA AABB CDE 18L SOIC XXXXXXXX XXXXXXXX AABB CDE Example PIC16LC84 04I/S0218 9310 CBA Legend: MM...M XX...X AA BB C Microchip part number information Customer specific information* Year code (last two digits of calendar year) Week code (week of January 1 is week ‘01’) Facility code of the plant at which wafer is manufactured C = Chandler, Arizona, U.S.A., S = Tempe, Arizona, U.S.A. D Mask revision number E Assembly code of the plant or country of origin in which part was assembled Note: In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line thus limiting the number of available characters for customer specific information. * Standard OTP marking consists of Microchip part number, year code, week code, facility code, mask rev#, and assembly code. For OTP marking beyond this, certain price adders apply. Please check with your Microchip Sales Office. For QTP devices, any special marking adders are included in QTP price. 1995 Microchip Technology Inc. DS30081F-page 111 PIC16C8X NOTES: DS30081F-page 112 1995 Microchip Technology Inc. PIC16C8X APPENDIX A: CHANGES APPENDIX B: COMPATIBILITY The following is the list of modifications over the PIC16C5X microcontroller family: To convert code written for PIC16C5X to PIC16C8X, the user should take the following steps: 1. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. Instruction word length is increased to 14 bits. This allows larger page sizes both in program memory (2K now as opposed to 512 before) and the register file (128 bytes now versus 32 bytes before). A PC latch register (PCLATH) is added to handle program memory paging. PA2, PA1 and PA0 bits are removed from the status register and placed in the option register. Data memory paging is redefined slightly. The STATUS register is modified. Four new instructions have been added: RETURN, RETFIE, ADDLW, and SUBLW. Two instructions, TRIS and OPTION, are being phased out although they are kept for compatibility with PIC16C5X. OPTION and TRIS registers are made addressable. Interrupt capability is added. Interrupt vector is at 0004h. Stack size is increased to 8 deep. Reset vector is changed to 0000h. Reset of all registers is revisited. Five different reset (and wake-up) types are recognized. Registers are reset differently. Wake up from SLEEP through interrupt is added. Two separate timers, the Oscillator Start-up Timer (OST) and Power-up Timer (PWRT), are included for more reliable power-up. These timers are invoked selectively to avoid unnecessary delays on power-up and wake-up. PORTB has weak pull-ups and interrupt on change features. T0CKI pin is also a port pin (RA4/T0CKI). FSR is a full 8-bit register. "In system programming" is made possible. The user can program PIC16CXX devices using only five pins: VDD, VSS, VPP, RB6 (clock) and RB7 (data in/out). 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 for reallocation. Verify all writes to STATUS, OPTION, and FSR registers since these have changed. Change reset vector to 0000h. 1995 Microchip Technology Inc. DS30081F-page 113 Thi d t t d ith F M k 404 PIC16C8X APPENDIX C: WHAT’S NEW APPENDIX D: WHAT’S CHANGED Here is an overview list of new features: The following lists the things that have changed: • Added descriptions and information for the PIC16C84A, PIC16CR84. PIC16C83 and PIC16CR83 devices. 1. 2. 3. 4. 5. 6. DS30081F-page 114 Section 7.1 no longer says that the upper two bits of EEADR are not address decoded. These two bits are decoded, even when there is no data EEPROM at that location. Changed the format of the Register Definition Figures to be consistent with other new data sheets. Added parameter numbers to DC specs. Added description of MPLAB development tool software. Added new probes in Probe Specification table. Updated device family tables. 1995 Microchip Technology Inc. PIC16C8X APPENDIX E: PIC16C84 CONVERSION CONSIDERATIONS This appendix discusses some of the issues that you may encounter as you convert your design from a PIC16C84 to any of the newly introduced devices. These new devices are: • • • • PIC16C83 PIC16CR83 PIC16C84A PIC16CR84 Some of the issues that may be encountered are: 1. 2. 3. 4. The polarity of the PWRTE configuration bit has been reversed. Ensure that the programmer has this bit correctly set before programming. The PIC16C84A and PIC16CR84 have larger RAM sizes. Ensure that this does not cause an issue with your program. The MCLR pin now has an on-chip filter. The input signal on the MCLR pin will require a longer low pulse to generate an interrupt. Many electrical specifications have been improved. Compare the electrical specifications of the two devices to ensure that this will not cause a compatibility issue. 1995 Microchip Technology Inc. DS30081F-page 115 PIC16C8X NOTES: DS30081F-page 116 1995 Microchip Technology Inc. WORLDWIDE SALES & SERVICE AMERICAS AMERICAS (continued) EUROPE Corporate Office Microchip Technology Inc. 2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 602 786-7200 Fax: 602 786-7277 Technical Support: 602 786-7627 Web: http://www.mchip.com/microhip Atlanta Microchip Technology Inc. 500 Sugar Mill Road, Suite 200B Atlanta, GA 30350 Tel: 770 640-0034 Fax: 770 640-0307 Boston Microchip Technology Inc. 5 Mount Royal Avenue Marlborough, MA 01752 Tel: 508 480-9990 Fax: 508 480-8575 Chicago Microchip Technology Inc. 333 Pierce Road, Suite 180 Itasca, IL 60143 Tel: 708 285-0071 Fax: 708 285-0075 Dallas Microchip Technology Inc. 14651 Dallas Parkway, Suite 816 Dallas, TX 75240-8809 Tel: 214 991-7177 Fax: 214 991-8588 Dayton Microchip Technology Inc. 35 Rockridge Road Englewood, OH 45322 Tel: 513 832-2543 Fax: 513 832-2841 Los Angeles Microchip Technology Inc. 18201 Von Karman, Suite 455 Irvine, CA 92715 Tel: 714 263-1888 Fax: 714 263-1338 New York Microchip Technology Inc. 150 Motor Parkway, Suite 416 Hauppauge, NY 11788 Tel: 516 273-5305 Fax: 516 273-5335 San Jose Microchip Technology Inc. 2107 North First Street, Suite 590 San Jose, CA 95131 Tel: 408 436-7950 Fax: 408 436-7955 United Kingdom Arizona Microchip Technology Ltd. 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Hong Kong Tel: 852 2 401 1200 Fax: 852 2 401 3431 Korea Microchip Technology 168-1, Youngbo Bldg. 3 Floor Samsung-Dong, Kangnam-Ku, Seoul, Korea Tel: 82 2 554 7200 Fax: 82 2 558 5934 Singapore Microchip Technology 200 Middle Road #10-03 Prime Centre Singapore 188980 Tel: 65 334 8870 Fax: 65 334 8850 Taiwan Microchip Technology 10F-1C 207 Tung Hua North Road Taipei, Taiwan, ROC Tel: 886 2 717 7175 Fax: 886 2 545 0139 JAPAN Microchip Technology Intl. Inc. Benex S-1 6F 3-18-20, Shin Yokohama Kohoku-Ku, Yokohama Kanagawa 222 Japan Tel: 81 45 471 6166 Fax: 81 45 471 6122 9/22/95 All rights reserved. 1995, Microchip Technology Incorporated, USA. Information contained in this publication regarding device applications and the like is intended through suggestion only and may be superseded by updates. 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