s2.asm

很小很弱的51单片机的四字节BCD码转换程序不过很多课堂练习可以参考

     ORG 0000H
     JMP 1000H


     ORG 1000H
MAIN:MOV A,#01H
     MOV 20H,A
     MOV A,#00H
     MOV 21H,A
     MOV A,#00H
     MOV 22H,A
     MOV A,#00H
     MOV 23H,A
     MOV A,#80H
     MOV 24H,A

     MOV A,#00H
     MOV 30H,A    
     MOV 31H,A     
     MOV 32H,A     
     MOV 33H,A     
     MOV 34H,A  

      
     MOV R7,#32
     
QUAN:CLR C
     MOV R0,#20H
     MOV R6,#05H
ROTA:MOV A,@R0
     RLC A
     MOV @R0,A
     INC R0
     DJNZ R6,ROTA
     JNC NEXT
     
MyAd:MOV R6,#05H
     MOV A,R7
     DEC A
     MOV B,#05
     MUL AB
     ADD A,#14
     MOV R1,#30H
     CLR C
TRAN:MOVC A,@A+PC
     MOV 40H,A    ;2
     ADD A,@R1    ;1
     MOV @R1,A    ;1
     MOV A,40H    ;2
     INC A        ;1
     INC R1       ;1
     DJNZ R6,TRAN ;2     
NEXT:DJNZ R7,QUAN  ;2
     SJMP $        ;2     
DTAB:DB 00H,00H,00H,00H,00H
     DB 01H,00H,00H,00H,00H
     DB 02H,00H,00H,00H,00H
     DB 04H,00H,00H,00H,00H
     DB 08H,00H,00H,00H,00H
     DB 16H,00H,00H,00H,00H
     DB 32H,00H,00H,00H,00H
     DB 64H,00H,00H,00H,00H
     DB 28H,01H,00H,00H,00H
     DB 56H,02H,00H,00H,00H
     DB 12H,05H,00H,00H,00H
     DB 24H,10H,00H,00H,00H
     DB 48H,20H,00H,00H,00H
     DB 96H,40H,00H,00H,00H
     DB 92H,81H,00H,00H,00H
     DB 84H,63H,01H,00H,00H
     DB 68H,27H,03H,00H,00H
     DB 36H,55H,06H,00H,00H
     DB 72H,10H,13H,00H,00H
     DB 44H,21H,26H,00H,00H
     DB 88H,42H,52H,00H,00H
     DB 76H,85H,04H,01H,00H
     DB 52H,71H,09H,02H,00H
     DB 04H,43H,19H,04H,00H
     DB 08H,86H,38H,08H,00H
     DB 16H,72H,77H,16H,00H
     DB 32H,44H,55H,33H,00H
     DB 64H,88H,10H,67H,00H
     DB 28H,77H,21H,34H,01H
     DB 56H,54H,43H,68H,02H
     DB 12H,09H,87H,36H,05H
     DB 24H,18H,74H,73H,10H
     DB 48H,36H,48H,47H,21H 
     DB 00H,00H,00H,00H,00H

    END