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SPECIAL PURPOSE REGISTERS

Although we have written Special Purpose Registers are located at 00 to 1F in the Instruction Set above (bank 0), they are also found in Bank 1. But you do not have to know their location or file number.

When writing a program, simply use the full name (from the list below) and the the assembler will locate the file number during assembly.
Most assemblers have a built-in list with the names of all the registers and file numbers. For a PIC16F628, the list is: P16F628A.inc It is called a .inc file (include file).
When writing a program, place the following instructions at the top:

LIST P=16F628A, F=INHX8M
include “P16F628A.inc”

In the same folder where your program is located, place the .inc file. The assembler will find the .inc file, read the name you have given to each file, and produce a file number.

Below are the names of the files. Write them in your program in lower case thus:

   btfss   status,z   ;test the zero bit and skip if set
   movlw   46h        ;put 46h into w
   movwf   porta      ;output 46h via port A

   bsf     portb,2    ;output a high on the third line of port B bsf    status,rp0  ;Select Bank 1 where the tris and other files are located
   bsf     trisb,1    ;Make the second line of port B output
   bcf     status,rp0 ;Get back to Bank 0 where PortA and PortB is located
   movlw   88h        ; "1000 1000"
   movlw   portb
;==================================================================
;
;   Register Definitions
;
;==================================================================

W                       EQU  H'0000'
F                       EQU  H'0001'

;----- Register Files----------------------------------------------

INDF                    EQU  H'0000'
TMR0                    EQU  H'0001'
PCL                     EQU  H'0002'
STATUS                  EQU  H'0003'
FSR                     EQU  H'0004'
PORTA                   EQU  H'0005'
PORTB                   EQU  H'0006'
PCLATH                  EQU  H'000A'
INTCON                  EQU  H'000B'
PIR1                    EQU  H'000C'
TMR1L                   EQU  H'000E'
TMR1H                   EQU  H'000F'
T1CON                   EQU  H'0010'
TMR2                    EQU  H'0011'
T2CON                   EQU  H'0012'
CCPR1L                  EQU  H'0015'
CCPR1H                  EQU  H'0016'
CCP1CON                 EQU  H'0017'
RCSTA                   EQU  H'0018'
TXREG                   EQU  H'0019'
RCREG                   EQU  H'001A'
CMCON                   EQU  H'001F'

OPTION_REG              EQU  H'0081'
TRISA                   EQU  H'0085'
TRISB                   EQU  H'0086'
PIE1                    EQU  H'008C'
PCON                    EQU  H'008E'
PR2                     EQU  H'0092'
TXSTA                   EQU  H'0098'
SPBRG                   EQU  H'0099'
EEDATA                  EQU  H'009A'
EEADR                   EQU  H'009B'
EECON1                  EQU  H'009C'
EECON2                  EQU  H'009D'
VRCON                   EQU  H'009F'

;----- STATUS Bits ------------------------------------------------

IRP                     EQU  H'0007'
RP1                     EQU  H'0006'
RP0                     EQU  H'0005'
NOT_TO                  EQU  H'0004'
NOT_PD                  EQU  H'0003'
Z                       EQU  H'0002'
DC                      EQU  H'0001'
C                       EQU  H'0000'

;----- INTCON Bits ------------------------------------------------

GIE                     EQU  H'0007'
PEIE                    EQU  H'0006'
T0IE                    EQU  H'0005'
INTE                    EQU  H'0004'
RBIE                    EQU  H'0003'
T0IF                    EQU  H'0002'
INTF                    EQU  H'0001'
RBIF                    EQU  H'0000'

;----- PIR1 Bits --------------------------------------------------

EEIF                    EQU  H'0007'
CMIF                    EQU  H'0006'
RCIF                    EQU  H'0005'
TXIF                    EQU  H'0004'
CCP1IF                  EQU  H'0002'
TMR2IF                  EQU  H'0001'
TMR1IF                  EQU  H'0000'

;----- T1CON Bits -------------------------------------------------
T1CKPS1                 EQU  H'0005'
T1CKPS0                 EQU  H'0004'
T1OSCEN                 EQU  H'0003'
NOT_T1SYNC              EQU  H'0002'
TMR1CS                  EQU  H'0001'
TMR1ON                  EQU  H'0000'

;----- T2CON Bits -------------------------------------------------
TOUTPS3                 EQU  H'0006'
TOUTPS2                 EQU  H'0005'
TOUTPS1                 EQU  H'0004'
TOUTPS0                 EQU  H'0003'
TMR2ON                  EQU  H'0002'
T2CKPS1                 EQU  H'0001'
T2CKPS0                 EQU  H'0000'

;----- CCP1CON Bits -----------------------------------------------
CCP1X                   EQU  H'0005'
CCP1Y                   EQU  H'0004'
CCP1M3                  EQU  H'0003'
CCP1M2                  EQU  H'0002'
CCP1M1                  EQU  H'0001'
CCP1M0                  EQU  H'0000'

;----- RCSTA Bits -------------------------------------------------
SPEN                    EQU  H'0007'
RX9                     EQU  H'0006'
SREN                    EQU  H'0005'
CREN                    EQU  H'0004'
ADEN                    EQU  H'0003'
FERR                    EQU  H'0002'
OERR                    EQU  H'0001'
RX9D                    EQU  H'0000'

;----- CMCON Bits -------------------------------------------------

C2OUT                   EQU  H'0007'
C1OUT                   EQU  H'0006'
C2INV                   EQU  H'0005'
C1INV                   EQU  H'0004'
CIS                     EQU  H'0003'
CM2                     EQU  H'0002'
CM1                     EQU  H'0001'
CM0                     EQU  H'0000'

;----- OPTION Bits ------------------------------------------------

NOT_RBPU                EQU  H'0007'
INTEDG                  EQU  H'0006'
T0CS                    EQU  H'0005'
T0SE                    EQU  H'0004'
PSA                     EQU  H'0003'
PS2                     EQU  H'0002'
PS1                     EQU  H'0001'
PS0                     EQU  H'0000'

;----- PIE1 Bits --------------------------------------------------

EEIE                    EQU  H'0007'
CMIE                    EQU  H'0006'
RCIE                    EQU  H'0005'
TXIE                    EQU  H'0004'
CCP1IE                  EQU  H'0002'
TMR2IE                  EQU  H'0001'
TMR1IE                  EQU  H'0000'

;----- PCON Bits --------------------------------------------------

OSCF                    EQU  H'0003'
NOT_POR                 EQU  H'0001'
NOT_BO                  EQU  H'0000'
NOT_BOR                 EQU  H'0000'
NOT_BOD                 EQU  H'0000' ;Backwards compatability to 16F62X

;----- TXSTA Bits -------------------------------------------------
CSRC                    EQU  H'0007'
TX9                     EQU  H'0006'
TXEN                    EQU  H'0005'
SYNC                    EQU  H'0004'
BRGH                    EQU  H'0002'
TRMT                    EQU  H'0001'
TX9D                    EQU  H'0000'

;----- EECON1 Bits ------------------------------------------------
WRERR                   EQU  H'0003'
WREN                    EQU  H'0002'
WR                      EQU  H'0001'
RD                      EQU  H'0000'

;----- VRCON Bits -------------------------------------------------

VREN                    EQU  H'0007'
VROE                    EQU  H'0006'
VRR                     EQU  H'0005'
VR3                     EQU  H'0003'
VR2                     EQU  H'0002'
VR1                     EQU  H'0001'
VR0                     EQU  H'0000'

;==================================================================
;
;   RAM Definition
;
;==================================================================

  __MAXRAM H'01FF'
  __BADRAM H'07'-H'09', H'0D', H'13'-H'14', H'1B'-H'1E'
  __BADRAM H'87'-H'89', H'8D', H'8F'-H'91', H'93'-H'97', H'9E'
  __BADRAM H'105', H'107'-H'109', H'10C'-H'11F', H'150'-H'16F'
  __BADRAM H'185', H'187'-H'189', H'18C'-H'1EF'

;==================================================================
;
;   Configuration Bits
;
;==================================================================

_BODEN_ON               EQU  H'3FFF'
_BODEN_OFF              EQU  H'3FBF'
_BOREN_ON               EQU  H'3FFF'
_BOREN_OFF              EQU  H'3FBF'
_CP_ON                  EQU  H'1FFF'
_CP_OFF                 EQU  H'3FFF'
_DATA_CP_ON             EQU  H'3EFF'
_DATA_CP_OFF            EQU  H'3FFF'
_PWRTE_OFF              EQU  H'3FFF'
_PWRTE_ON               EQU  H'3FF7'
_WDT_ON                 EQU  H'3FFF'
_WDT_OFF                EQU  H'3FFB'
_LVP_ON                 EQU  H'3FFF'
_LVP_OFF                EQU  H'3F7F'
_MCLRE_ON               EQU  H'3FFF'
_MCLRE_OFF              EQU  H'3FDF'
_RC_OSC_CLKOUT          EQU  H'3FFF'
_RC_OSC_NOCLKOUT        EQU  H'3FFE'
_ER_OSC_CLKOUT          EQU  H'3FFF'
_ER_OSC_NOCLKOUT        EQU  H'3FFE'
_INTOSC_OSC_CLKOUT      EQU  H'3FFD'
_INTOSC_OSC_NOCLKOUT    EQU  H'3FFC'
_INTRC_OSC_CLKOUT       EQU  H'3FFD'
_INTRC_OSC_NOCLKOUT     EQU  H'3FFC'
_EXTCLK_OSC             EQU  H'3FEF'
_HS_OSC                 EQU  H'3FEE'
_XT_OSC                 EQU  H'3FED'
_LP_OSC                 EQU  H'3FEC'

ADDITIONAL INSTRUCTIONS

ADDWF PCL,1 ADDWF 02,1 Alter the program counter to create a jump
CLRF INDF,1 CLRF 00,1 Clear INDIRECT file
INCF FSR,1 INCF 04,1 Increment the File Select Register

INTCON address is either 0Bh or 8Bh - it is mapped at both locations.
BCF INTCON,RBIF Clear RB<7:4> Port-change Interrupt flag
BSF INTCON,RBIF Set RB<7:4> Port-change Interrupt flag
BCF INTCON,RBIE Disables the Port-change Interrupt
BSF INTCON,RBIE Enables the Port-change Interrupt
BCF INTCON,INTE Disables the RB0/INT Interrupt
BSF INTCON,INTE Enables the RB0/INT Interrupt
BCF INTCON,T0IE Disables the TMR0 Interrupt
BSF INTCON,T0IE Enables the TMR0 Interrupt
BCF INTCON,EEIE Disables the EE write complete Interrupt
BSF INTCON,EEIE Enables the EE write complete Interrupt
BCF INTCON,GIE Disables all Interrupts
BSF INTCON,GIE Enables all un-masked Interrupts

OPTION address is 81h - use the word OPTION
OPTION,0 OPTION,1 OPTION,2 Prescaler Rate Select Bits

e:g:
BSF OPTION,0 BCF OPTION,1 BSF OPTION,2 TMR0 Rate = 1:64 WDT Rate = 1:32
BSF OPTION,0 BSF OPTION,1 BSF OPTION,2 TMR0 Rate = 1:256 WDT Rate = 1:128

BCF OPTION,PSA BCF OPTION,3 Prescaler assigned to TMR0
BSF OPTION,PSA BSF OPTION,3 Prescaler assigned to the WDT
BCF OPTION,T0SE BCF OPTION,4 Increment on low-to-high on RA4/T0CKI pin
BSF OPTION,T0SE BSF OPTION,4 Increment on high-to-low on RA4/T0CKI pin
BCF OPTION,T0CS BCF OPTION,5 Internal Instruction cycle clock (CLKOUT)
BSF OPTION,T0CS BSF OPTION,5 Clock source select. Transition on RA4/T0CKI Pin
BCF OPTION,INTEDG BCF OPTION,6 Interrupt on falling edge of RB0/INT Pin
BSF OPTION,INTEDG BSF OPTION,6 Interrupt on rising edge of RB0/INT Pin
BCF OPTION,RBPU BCF OPTION,7 PORT B Pull-ups are enabled
BSF OPTION,RBPU BSF OPTION,7 PORT B Pull-ups are disabled

STATUS address is either 03h or 83h - it is mapped at both locations.
BTFSS STATUS,C or BTFSC 03,0 Test the carry bit. C=1=set = carry occurred
BTFSS STATUS,C or BTFSC 03,0 Test the carry bit. C=0=reset = carry did not occur
BTFSS STATUS,DC BTFSS 03,1 Test the digit carry bit. C=1=set = carry-out from the
4th lower order bit of the result occurred.
BTFSS STATUS,DC BTFSS 03,1 Test the digit carry bit. C=0=reset = carry-out did not
occur from the 4th lower order bit of the result.
BTFSS STATUS,Z or BTFSC 03,2 Test the zero bit. Z=1=set = result of arithmetic
or logic operation is zero.
BTFSS STATUS,Z or BTFSC 03,2 Test the zero bit. Z=0=reset = result of arithmetic
or logic operation is not zero.
BSF STATUS,RP0 BSF 03,5 Go to Bank1 for TRISA or TRISB register
BCF STATUS,RP0 BCF 03,5 Go to Bank0 for programming

CLRF INDF,1 CLRF 00,1 Clear INDIRECT file

RETFIE Return from Interrupt Sets INTCON,GIE