说明：  采用MSC-51系列单片机ATSC51和可编程并行I/O接口芯片8255A为中心器件来设计交通灯控制器，实现了能根据实际车流量通过8051芯片的P1口设置红、绿灯燃亮时间的功能；红绿灯循环点亮，倒计时剩5秒时黄灯闪烁警示
(By MSC-51 Series MCU ATSC51 and programmable parallel I/O interface chip 8255A is designed as the center of traffic light controller device to realize the actual traffic flow according to the P1 port through 8051 to set the red, green kindle function of time traffic light cycle lights, countdown 5 seconds left when the yellow light flashing warning)