led.asm

4位led显示

      ORG 0000H
      SJMP START
      ORG 0030H
START:MOV R0,#30H
      MOV @R0,#01H
      INC R0
      MOV @R0,#02H
      INC R0
      MOV @R0,#03H
      INC R0
      MOV @R0,#04H
 MAIN:MOV R0,#30H
      MOV R1,#04H
      MOV R2,#10H
 DISP:MOV A,@R0
      MOV DPTR,#DISP_CODE
      MOVC A,@A+DPTR
      MOV P2,A
      MOV A,R2
      MOV P3,A
      ACALL DELAY
      INC R0
      RL A
      MOV R2,A
      DJNZ R1,DISP
      AJMP MAIN
DISP_CODE:DB 40H,79H,24H,30H,19H,12H,02H,78H
          DB 00H,10H,08H,03H,46H,21H,06H,0EH
DELAY:MOV R4,#10
    D1:MOV R5,#10
    D2:DJNZ R5,D2
       DJNZ R4,D1
       RET

       END