PIC microcontroller converts 2 hexadecimal numbers into 5-digit decimal numbers and displays them

  
   W_TEMP EQU 20H; Actually 20H, A0H, 120H and 1A0H
   STATUS_TEMP EQU 21H ;Create protection unit in bank 0
   PCLATH_TEMP EQU 22H ;Create protection unit in bank 0

   ORG 000H
   GOTO A1
   ORG 004H; timing interrupt entry address
   GOTO ZD01;
   ORG 0CH
A1  
   MOVLW 1; bit 1 displays the number
   MOVWF 5AH;
   MOVLW 2; bit 2 displays the number
   MOVWF 5BH;
   MOVLW 3; bit 3 displays the number
   MOVWF 5CH;
   MOVLW 4; bit 4 displays the number
   MOVWF 5DH;
   MOVLW 4; Display digits
   MOVWF 40H;
   MOVLW B'00000001'; bit code
   MOVWF 41H;
   MOVLW 5AH;
   MOVWF FSR ; indirect addressing
   BSF STATUS, RP0; select body 1
   BCF STATUS,RP1;
   MOVLW 00H; 1:2TMRO ratio
   MOVWF OPTION_REG; divide by 1/2
   BCF STATUS, RP0; BODY0
   BCF STATUS,RP1;
   MOVLW 0FFH;
   MOVFW TMR0; initial value
   BCF INTCON, T0IF; clear the timing interrupt flag
   BSF INTCON, T0IE; open timer interrupt
   BSF INTCON, GIE; open general interrupt
  
 
  
A2 CALL CL0; adjust the hexadecimal number to a 5-digit decimal number
   NOP;
   NOP;
   MOVFW 50H
   MOVWF 5AH
   MOVFW 51H
   MOVWF 5BH
   
   MOVFW 52H
   MOVWF 5CH
   MOVFW 53H
   MOVWF5DH
 

   GOTO A2
CL0; MOVLW 0H; To display the low digit of the hexadecimal number
  ; MOVWF 50H;
  ; MOVLW 00H;
  ; MOVWF 51H; To display the high digit of the hexadecimal number
   CALL CL1
   
   MOVLW B'00001111'
   ANDWF 54H,0
   MOVWF 50H
   MOVLW B'11110000'
   ANDWF 54H,1
   SWAPF 54H,0
   MOVWF 51H
     
   MOVFW 52H
   MOVWF 54H
   MOVLW B'00001111'
   ANDWF 53H,0
   MOVWF 52H
   MOVLW B'11110000'
   ANDWF 53H,1
   SWAPF 53H,1
   RETURN
  
    
CL1  
   MOVLW 0;
   MOVWF 52H; ten thousand digit
   MOVWF 53H; hundreds and thousands of bits
   MOVWF 54H; Tens digit
   MOVWF 55H; carry flag
   MOVLW 10H;
   MOVWF 56H;Number of cycles
   CLRF 57H;
CL2 BCF STATUS, C; Clear C
   RLF 51H,1; Circular left shift
   RLF 50H,1; Circular left shift
   BTFSC STATUS, C; Check whether the C bit is high
   BSF 55H,0; is set to 1
   MOVFW 54H;
   ADDWF 55H,0; PIC does not have ADDC instruction, it can only judge C to add 1
   ADDWF 54H,0; add to itself
   BTFSC STATUS, C; Determine whether there is a carry
   BSF 57H,7; Set flag if yes
   BTFSC STATUS, DC; Determine whether there is a carry
   BSF 57H,3; Set flag if yes
   CALL DA1; Call the decimal adjustment subroutine
   MOVWF 54H; store back to 54H
   CLRF 55H; clear carry flag
   BTFSC STATUS, C; Check whether the C bit is high
   BSF 55H,0; is set to 1
   MOVFW 53H;
   ADDWF 55H,0; PIC does not have ADDC instruction, it can only judge C to add 1
   ADDWF 53H,0; add to itself
   BTFSC STATUS,C;
   BSF 57H,6;
   
   BTFSC STATUS, DC; Determine whether there is a carry
   BSF 57H,2; Set flag if yes
   
   CALL DA1;
   MOVWF 53H;
   CLRF 55H ;
   BTFSC STATUS,C;
   BSF 55H,0;
   MOVFW 52H;
   ADDWF 55H,0;
   ADDWF 52H,0;
   BTFSC STATUS,C;
   BSF 57H,5;
   BTFSC STATUS, C; Determine whether there is a carry
   BSF 57H,1; Set flag if yes
 
   CALL DA1;
   MOVWF 52H;
   CLRF 55H;
   BTFSS 57H,7; Check if the flag has a carry
   GOTO CL03; No
   INCF 53H,1; is carry
   MOVLW 60H;
   ADDWF 54H,1; add 60H to itself
CL03 BTFSS 57H,3; Check if there is a carry flag
   GOTO CL3; No
   MOVLW 6H;
   ADDWF 54H,1; add 6H to itself
 
CL3 BTFSS 57H,6; Check whether the flag has a carry
   GOTO CL04;
   INCF 52H,1; is carry
   MOVLW 60H;
   ADDWF 53H,1; add 60H to itself
   
CL04 BTFSS 57H,2; Check if there is a carry flag
   GOTO CL4; No
   MOVLW 6H;
   ADDWF 53H,1; add 6H to itself  
CL4 BTFSS 57H,5; Check if there is a carry flag
   GOTO CL05;
   INCF 51H,1; is carry
   MOVLW 60H;
   ADDWF 52H,1; add 60H to itself
CL05 BTFSS 57H,1; Check if there is a carry flag
   GOTO CL5; No
   MOVLW 6H;
   ADDWF 52H,1; add 6H to itself
CL5   
   CLRF 57H; Clear flag
   DECFSZ 56H,1;
   GOTO CL2;
  
   RETURN;
 
 [page]
 
;;;**************************************************** ***************
;;; Decimal adjustment
;;;****************************************************** ***************   
DA1 MOVWF 60H; save the number in W to 60H
   MOVLW B'00001111';
   ANDWF 60H,0; add the number 60H to 00001111 and remove the high 4 bits
   MOVWF 62H; save the number after removing the high bit to 62H
   MOVLW 0AH;
   SUBWF 62H,0; remove the high-order number minus 0AH
   BTFSS STATUS, DC; Check whether it is greater than 0AH
   GOTO DA2; otherwise jump
   ADDLW B'10000'; if it is greater than 0AH, carry
   MOVWF 62H; add 1 to the upper 4 bits
  
DA2 MOVLW B'11110000';
   ANDWF 60H,1; add the number in 60H and 11110000 to remove the lower 4 bits
   MOVLW 0A0H;
   SUBWF 60H,0; Subtract 0A0H from the high 4 bits
   BTFSS STATUS, C; Determine whether it is greater than 0A0H
   GOTO DA3; No
   ADDWF 62H,1; if yes, add the difference to the low bit
   BSF STATUS, C; if yes, set
   GOTO DA4;
DA3 MOVFW 60H;
   ADDWF 62H,1; otherwise add the high 4 bits to the low 4 bits
   MOVFW 62H;
   ANDLW B'11110000';
   SUBLW 0A0H ; after adding, check whether it is greater than or equal to 0A0H
   BCF STATUS,C;
   BTFSS STATUS,Z;
   GOTO DA4; otherwise exit
   MOVLW B'00001111'; yes
   ANDWF 62H,1; remove the high 4 bits and carry
   BSF STATUS, C; Set carry flag
DA4 MOVFW 62H;
   RETURN;
 

;****************************************************** *************
; Timed interruption of digital tube display program
;****************************************************** *************
ZD01 BTFSS INTCON, T0IF; Determine whether a timing interrupt occurs
   GOTO ZD03; No, jump out, continue to execute
   MOVWF W_TEMP;W is backed up to W_TEMP
   SWAPF STATUS, 0; STATUS half word swap and send W
   CLRF STATUS; Select body 0 as the current body backup
   MOVWF STATUS_TEMP; send the original STATUS to the
   MOVF PCLATH,0;PCLATH sends W
   MOVWF PCLATH_TEMP;W is sent to the backup register
   CLRF PCLATH ; set to 0 pages
 
   BCF INTCON,T0IF
   BSF STATUS, RP0; BODY1
   BCF STATUS,RP1;
   MOVLW 0;
   MOVWF TRISB; RB port is set as output port
   MOVWF TRISD; RD port is set as output port
   BCF STATUS, RP0; BODY0
   BCF STATUS,RP1;
   MOVLW 0FFH;
   MOVWF PORTB; RB port outputs high level
   MOVLW 0
   MOVWF PORTD; RD port outputs low level to clear the screen
   
   MOVFW INDF; indirect addressing display data  
   CALL Q1; check the data table
   MOVWF PORTB; Display the broken code output to port RB
   INCF FSR,1; Indirect addressing address plus 1
   MOVFW 41H ; bit code
   MOVWF PORTD; bit code output to RD port
   RLF 41H,0; Process C
   RLF 41H,1; left shift code
   DECFSZ 40H,1; Determine whether the 4 bits are displayed
   GOTO ZD02; otherwise continue to display
   MOVLW 4; Display digits
   MOVWF 40H;
   MOVLW B'00000001'; bit code
   MOVWF 41H;
   MOVLW 5AH;
   MOVWF FSR ; indirect addressing
ZD02  
   MOVLW 0FFH;
   MOVFW TMR0; reload initial value
     ; Restore the scene
   CLRF STATUS; Restore to body 0
   MOVF PCLATH_TEMP,0; start to recover data
   MOVWF PCLATH; restore PCLATH
   SWAPF STATUS_TEMP,0
   MOVWF STATUS; RESTORE STATUS
   SWAPF W_TEMP,1; put back after half word swap
   SWAPF W_TEMP,0; then swap half words and send W
ZD03  
   RETFIE ;Interrupt return
M001 MOVLW 4
   MOVWF 30H
M002 MOVLW 248
   MOVWF 31H
M003 MOVLW 250
   MOVWF 32H
   DECFSZ 32H
   GOTO $-1
   DECFSZ 31H
   GOTO M003
   DECFSZ 30H
   GOTO M002
   RETURN
  
   
 
;************************************************
; data sheet
;************************************************      
Q1 ADDWF PCL,1  
      RETLW 00C0H ;0
      RETLW 00F9H ;1
      RETLW 00A4H ;2
      RETLW 00B0H ;3
      RETLW 0099H ;4
      RETLW 0092H ;5
      RETLW 0082H ;6
      RETLW 00F8H ;7
      RETLW 0080H ;8
      RETLW 0090H ;9
      RETLW 0088H ;A
      RETLW 0083H ;B
      RETLW 00C6H ;C
      RETLW 00A1H ;D
      RETLW 0086H ;E
      RETLW 008EH ;F
   END