本程序设计需应用软件控制并运行接口电路，使连接在该接口上的红、绿、黄发光二极管按十字路*通红、绿、黄灯形式闪烁，并显示绿灯的倒计时时间。

　　程序一开始，四个方向的灯全为红灯，接着变为黄灯闪烁，然后东西方向为红灯，南北方向为绿灯并显示倒计时时间，倒计时间结束后，交通灯变成黄灯，闪烁几次后，东西方向变成绿灯，南北变成红灯，再变成黄灯，如此按交通灯的变化规则交替变化

-This program designed to take control and run the application software interface circuits, so that the interface connected to the red, green and yellow light-emitting diode according to the traffic intersection of red, green, yellow form of flashing, and display the countdown time for the green light. Program started, the four directions of the lights are all red, and then into a yellow light flashes, and then east-west direction for the red light, green light north-south direction and display the countdown time, countdown to the end, traffic lights into a yellow light, blinking After several east-west direction to become a green light from north to south into a red light, and then become yellow, and so the rules change according to the traffic lights alternating