不挂科搜题免费

问题:

设计数器/定时器8253在微机系统中的端口地址分配如下:O # 计数器为340H,1 # 计数器为3

答案:

MOV AL,36H MOV DX,343H OUT DX,AL MOV AL,10H MOV DX,340H OUT DX,AL MOV AL,27H OUT DX,AL MOV AL,52H MOV DX,343H OUT DX,AL MOV AL,64H MOV DX,341H OUT DX,AL MOV AL,10H OUT DX,AL