本系统采用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（交通灯信号通过PA口输出，显示时间直接通过8255的PC口输出至双位数码管）；车辆闯红灯报警；绿灯时间可检测车流量并可通过双位数码管显示。本系统实用性强、操作简单、扩展功能强。 -The system uses the MSC-51 Series MCU ATSC51 and programmable parallel I/O interface chip 8255A-centric devices to design the traffic light controller, which can realize the basis of actual traffic flow through the P1 port 8051 chip set red, green fuel Liang time function　traffic lights lit cycle, the countdown five seconds left when the yellow light flashing warning (traffic lights signal through the PA output, indicating the time directly through the PC port output 8255 to double-digit digital tube)　vehicles闯红灯alarm　green time can detect the flow through a double-digital tube display. The system practical, simple operation, the expansion of strong functions.