欢迎使用CSDN-markdown编辑器

ORG 00H
MAIN:
MOV P0,#00H
MOV P1,#00H
MOV P2,#00H
MOV P3,#00H
CALL DELAY
MOV P0,#FFH
MOV P1,#FFH
MOV P2,#FFH
MOV P3,#FFH
CALL DELY
JMP MAIN
DELAY:
MOV R3,#50
D1:
MOV R4,#20
D2:
MOV R5,#248
DJNZ R5,$
DJNZ R4,D2
DJNZ R3,D1
RET
END