计算机原理交通灯源程序

DATA SEGMENT 
IO_8255C  EQU  202H
IO_8255K  EQU  203H
PORTCL  DB 0CH,14H,21H,22H,0FFH
DATA ENDS
CODE  SEGMENT
      ASSUME  CS:CODE,DS:DATA
START :
MOV AX,DATA
  MOV DS,AX
MOV DX,IO_8255K
MOV AL,90H
OUT DX,AL
MOV DX,IO_8255C
RE_ON:
MOV BX,0
ON:
MOV AL,PORTCL[BX]
CMP AL,0FFH
JZ RE_ON
OUT DX,AL
INC BX
MOV CX,4000
AP1:
MOV DI,1000
AP0:
DEC DI
    JNZ AP0
LOOP AP1
PUSH DX