Datasheet PIC16F84A (Microchip) - 80

PIC16F84A APPENDIX C: MIGRATION FROM
To convert code written for PIC16C5X to PIC16F84A,
BASELINE TO
the user should take the following steps:
MID-RANGE DEVICES
1. Remove any program memory page select operations (PA2, PA1, PA0 bits) for CALL, GOTO. This section discusses how to migrate from a baseline 2. Revisit any computed jump operations (write to device (i.e., PIC16C5X) to a mid-range device (i.e., PC or add to PC, etc.) to make sure page bits PIC16CXXX). are set properly under the new scheme. The following is the list of feature improvements over 3. Eliminate any data memory page switching. the PIC16C5X microcontroller family: Redefine data variables for reallocation. 1. Instruction word length is increased to 14-bits. 4. Verify all writes to STATUS, OPTION, and FSR This allows larger page sizes, both in program registers since these have changed. memory (2K now as opposed to 512K before) 5. Change RESET vector to 0000h. and the register file (128 bytes now versus 32 bytes before). 2. A PC latch register (PCLATH) is added to han- dle program memory paging. PA2, PA1 and PA0 bits are removed from the STATUS register and placed in the OPTION register. 3. Data memory paging is redefined slightly. The STATUS register is modified. 4. 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. 5. OPTION and TRIS registers are made addressable. 6. Interrupt capability is added. Interrupt vector is at 0004h. 7. Stack size is increased to eight-deep. 8. RESET vector is changed to 0000h. 9. RESET of all registers is revisited. Five different RESET (and wake-up) types are recognized. Registers are reset differently. 10. Wake-up from SLEEP through interrupt is added. 11. 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. 12. PORTB has weak pull-ups and interrupt-on- change features. 13. T0CKI pin is also a port pin (RA4/T0CKI). 14. FSR is a full 8-bit register. 15. "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). DS35007C-page 80  2001-2013 Microchip Technology Inc. Document Outline 1.0 Device Overview FIGURE 1-1: PIC16F84A Block Diagram TABLE 1-1: PIC16F84A Pinout Description 2.0 Memory Organization 2.1 Program Memory Organization FIGURE 2-1: Program Memory Map and Stack - PIC16F84A 2.2 Data Memory Organization 2.2.1 General purpose Register File FIGURE 2-2: Register File Map - PIC16F84A 2.3 Special Function Registers TABLE 2-1: Special Function Register File Summary 2.3.1 STATUS Register Register 2-1: Status Register (Address 03h, 83h) 2.3.2 OPTION Register Register 2-2: OPTION Register (Address 81h) 2.3.3 INTCOn Register Register 2-3: INTCON Register (Address 0Bh, 8Bh) 2.4 PCL and PCLATH 2.4.1 Stack 2.5 Indirect Addressing; INDF and FSR Registers EXAMPLE 2-1: Indirect Addressing EXAMPLE 2-2: How to Clear RAM Using Indirect Addressing FIGURE 2-3: Direct/Indirect Addressing 3.0 Data EEPROM Memory Register 3-1: EECON1 Register (Address 88h) 3.1 Reading the EEPROM Data Memory EXAMPLE 3-1: Data EEPROM Read 3.2 Writing to the EEPROM Data Memory EXAMPLE 3-2: Data EEPROM Write 3.3 Write Verify EXAMPLE 3-3: Write Verify TABLE 3-1: Registers/Bits Associated with Data EEPROM 4.0 I/O Ports 4.1 PORTA and TRISA Registers EXAMPLE 4-1: Initializing PORTA FIGURE 4-1: Block Diagram of Pins RA3:RA0 FIGURE 4-2: Block Diagram of Pin RA4 TABLE 4-1: PORTA Functions TABLE 4-2: Summary of Registers Associated With PORTA 4.2 PORTB and TRISB Registers EXAMPLE 4-2: Initializing PORTB FIGURE 4-3: Block Diagram of Pins RB7:RB4 FIGURE 4-4: Block Diagram of Pins RB3:RB0 TABLE 4-3: PORTB Functions TABLE 4-4: Summary of Registers Associated With PORTB 5.0 Timer0 Module 5.1 Timer0 Operation 5.2 Prescaler FIGURE 5-1: Timer0 Block Diagram 5.2.1 Switching Prescaler ASSIGnment 5.3 Timer0 Interrupt FIGURE 5-2: Block Diagram of the Timer0/WDT Prescaler TABLE 5-1: Registers Associated with Timer0 6.0 Special Features of the CPU 6.1 Configuration Bits Register 6-1: PIC16F84A Configuration Word 6.2 Oscillator Configurations 6.2.1 Oscillator Types 6.2.2 Crystal Oscillator/CERAmic Resonators FIGURE 6-1: Crystal/Ceramic Resonator Operation (HS, XT or LP OSC Configuration) FIGURE 6-2: External Clock Input Operation (HS, XT or LP OSC Configuration) TABLE 6-1: Capacitor Selection for Ceramic Resonators TABLE 6-2: Capacitor Selection for Crystal Oscillator 6.2.3 RC Oscillator FIGURE 6-3: RC Oscillator Mode 6.3 Reset FIGURE 6-4: Simplified Block Diagram of On-Chip Reset Circuit TABLE 6-3: Reset Condition for Program Counter and the STATUS Register TABLE 6-4: Reset Conditions for All Registers 6.4 Power-on Reset (POR) 6.5 Power-up Timer (PWRT) 6.6 Oscillator Start-up Timer (OST) FIGURE 6-5: External Power-on Reset Circuit (For Slow Vdd Power-up) FIGURE 6-6: Time-out Sequence on Power-up (MCLR not Tied to Vdd): Case 1 FIGURE 6-7: Time-out Sequence on Power-up (MCLR Not Tied To Vdd): Case 2 FIGURE 6-8: Time-out Sequence on Power-up (MCLR Tied to Vdd): Fast Vdd Rise Time FIGURE 6-9: Time-Out Sequence on Power-Up (MCLR Tied to Vdd): Slow Vdd Rise Time 6.7 Time-out Sequence and Power-down Status Bits (TO/PD) TABLE 6-5: Time-out in Various Situations TABLE 6-6: STATUS bits and Their Significance 6.8 Interrupts FIGURE 6-10: Interrupt Logic 6.8.1 INT Interrupt 6.8.2 TMR0 Interrupt 6.8.3 PORTB Interrupt 6.8.4 Data EEPROM Interrupt 6.9 Context Saving During Interrupts EXAMPLE 6-1: Saving STATUS and W Registers in RAM 6.10 Watchdog Timer (WDT) 6.10.1 WDT Period 6.10.2 WDT Programming Considerations FIGURE 6-11: Watchdog Timer Block Diagram TABLE 6-7: Summary of Registers Associated With the Watchdog Timer 6.11 Power-down Mode (SLEEP) 6.11.1 SLEEP 6.11.2 Wake-up from SLEEP FIGURE 6-12: Wake-up From Sleep Through Interrupt 6.11.3 Wake-Up Using Interrupts 6.12 Program Verification/Code Protection 6.13 ID Locations 6.14 In-Circuit Serial Programming 7.0 Instruction Set Summary TABLE 7-1: Opcode Field Descriptions FIGURE 7-1: General Format for Instructions TABLE 7-2: PIC16CXXX Instruction Set 7.1 Instruction Descriptions 8.0 Development Support 9.0 Electrical Characteristics FIGURE 9-1: PIC16F84A-20 Voltage-Frequency Graph FIGURE 9-2: PIC16LF84A-04 Voltage- Frequency Graph FIGURE 9-3: PIC16F84A-04 Voltage- Frequency Graph 9.1 DC Characteristics 9.2 DC Characteristics: PIC16F84A-04 (Commercial, Industrial) PIC16F84A-20 (Commercial, Industrial) PIC16LF84A-04 (Commercial, Industrial) 9.3 AC (Timing) Characteristics 9.3.1 Timing Parameter Symbology 9.3.2 Timing Conditions TABLE 9-1: Temperature and Voltage Specifications - AC FIGURE 9-4: Parameter Measurement Information FIGURE 9-5: Load Conditions 9.3.3 Timing Diagrams and Specifications FIGURE 9-6: External Clock Timing TABLE 9-2: External Clock Timing Requirements FIGURE 9-7: CLKOUT and I/O Timing TABLE 9-3: CLKOUT and I/O Timing Requirements FIGURE 9-8: Reset, Watchdog Timer, Oscillator Start-up Timer and Power-up Timer Timing TABLE 9-4: Reset, Watchdog Timer, Oscillator Start-up Timer and Power-up Timer Requirements FIGURE 9-9: Timer0 Clock Timings TABLE 9-5: Timer0 Clock Requirements 10.0 DC/AC Characteristic Graphs FIGURE 10-1: Typical Idd vs. Fosc OVER Vdd (HS Mode, 25°C) FIGURE 10-2: Maximum Idd vs. Fosc OVER Vdd (HS Mode, -40° to +125°C) FIGURE 10-3: Typical Idd vs. Fosc OVER Vdd (XT Mode, 25°C) FIGURE 10-4: Maximum Idd vs. Fosc OVER Vdd (XT Mode, -40° to +125°C) FIGURE 10-5: Typical Idd vs. Fosc OVER Vdd (LP Mode, 25°C) FIGURE 10-6: Maximum Idd vs. Fosc OVER Vdd (LP Mode, -40° to +125°C) FIGURE 10-7: Average Fosc vs. Vdd for R (RC Mode, C = 22 pF, 25°C) FIGURE 10-8: Average Fosc vs. Vdd for R (RC Mode, C = 100 pF, 25°C) FIGURE 10-9: Average Fosc vs. Vdd for R (RC Mode, C = 300 pF, 25°C) FIGURE 10-10: Ipd vs. Vdd (Sleep Mode, all peripherals disabled) FIGURE 10-11: Ipd vs. Vdd (WDT Mode) FIGURE 10-12: Typical, Minimum, and Maximum WDT Period vs. Vdd over Temp FIGURE 10-13: Typical, Minimum and Maximum Voh vs. Ioh (Vdd = 5V, -40°C to +125°C) FIGURE 10-14: Typical, Minimum and Maximum Voh vs. Ioh (Vdd = 3V, -40°C to +125°C) FIGURE 10-15: Typical, Minimum and Maximum Vol vs. Iol (Vdd = 5V, -40°C to +125°C) FIGURE 10-16: Typical, Minimum and Maximum Vol vs. Iol (Vdd = 3V, -40°C to +125°C) FIGURE 10-17: Minimum and Maximum Vin vs. Vdd, (TTL Input, -40°C to +125°C) FIGURE 10-18: Minimum and Maximum Vin vs. Vdd (ST Input, -40°C to +125°C) 11.0 Packaging Information 11.1 Package Marking Information Appendix A: Revision History Appendix B: Conversion Considerations Appendix C: Migration from Baseline to Mid-range Devices A B C D E F I M O P R S T W Z The Microchip Web Site Customer Change Notification Service Customer Support Reader Response Corporate Office Atlanta Boston Chicago Cleveland Fax: 216-447-0643 Dallas Detroit Indianapolis Toronto Fax: 852-2401-3431 Australia - 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