补充接口程序实现以下要求:
当只有最上面的开关为ON,8个LED灯全亮;
当只有最下面的开关为ON,中间4个LED灯亮;
当开关全部为ON,8个LED灯闪烁发光;
当开关为其余状态时,所有的LED灯全灭。
OUT373 EQU 0FF80H
IN245 EQU 0FF80H
CODE SEGMENT
ASSUME CS:CODE
START:
MOV DX,IN245
IN AL,DX
NOT AL
CMP AL,00000001B
JNZ A2
MOV AL,11111111B
JMP A1
A2: CMP AL,10000000B
JNZ A3
MOV AL,00111100B
JMP A1
A3: CMP AL,11111111B
JNZ A4
JMP A5
A4: MOV AL,00000000B
JMP A1
A5: MOV AL,11111111B
A6: NOT AL
MOV DX,OUT373
OUT DX,AL
LOOP A6
A1: MOV DX,OUT373
OUT DX,AL
JMP START
CODE ENDS
END START