MOV AL,38H ;写显示命令 OUT DX,AL

CALL CLEAR_LED ;清除显示RAM，数码管熄灭

WORK:

CALL WORK1 JMP WORK

WORK1 PROC NEAR SHOW1:

MOV AL,11111001B ;1绿2红 MOV DX,D8255A OUT DX,AL

CALL WORK2 ;倒数50秒，并显示60~10

MOV DX,D8255A

MOV AL,11111101B ;1绿灭 OUT DX,AL

YELLOW1: MOV DX,D8255A

MOV AL,11101101B ;1黄2红 OUT DX,AL CALL WORK3

MOV DX,D8255A

MOV AL,11111101B ;1号黄灯灭 OUT DX,AL

;2号线（东西）通车

MOV AL,11110110B ;2绿1红 MOV DX,D8255A OUT DX,AL

CALL WORK2

MOV DX,D8255A

MOV AL,11111110B ;2绿灭 OUT DX,AL