演示89C52响应中断：没有中断时，4个LED灯以闪烁为主，响应中断后则以广告灯的形式显示。由于采用下降沿触发，所以对于中断有一次记忆功能。-Demo 89C52 to respond to interrupts: No interrupt when the four LED lights to flash the main, the response disruption Zeyi advertising in the form of light display. As a result of falling edge trigger, so there is a memory function for the interruption.