MCS51外部中断1和定时器T0的应用，外部中断1连接一个按键，通过调节按键改变定时器的值，定时器输出连接一个蜂鸣器-MCS51 and one external interrupt timer T0 applications, external interrupt 1 to connect a button, through the adjustment button to change the timer value, the timer output to connect a buzzer