;動態掃描數碼顯示程序
ORG 00H
MOV 20H,#3FH
MOV 21H,#06H
MOV 22H,#5BH
MOV 23H,#4FH
MOV 24H,#66H
MOV 25H,#6DH
MOV 26H,#7DH
MOV 27H,#07H
START:CALL SCAN
      JMP START
SCAN: MOV A,#0   ;掃描子程序
      MOV R0,#20H
      MOV R2,#8
LOOP: 

     MOV P2,A
     MOV P0,@R0
     INC R0
     CALL DELAY
     ADD A,#01H
     DJNZ R2,LOOP
     MOV R2,#8
     CLR A
     RET
DELAY:MOV R3,#1  ;掃描延時
D1:MOV R4,#2
D2:MOV R5,#248
   DJNZ R5,$
   DJNZ R4,D2
   DJNZ R3,D1
   RET
   END