本程序模拟交通灯的基本状态控制，当程序开始工作时，东西南北路口灯均为红色, 持续5s，作为缓冲时间。之后，东西通行，东西绿灯亮25s，南北红灯亮30s，接下来东西紧示，

南北继续禁行。之后，南北通行，南北绿灯亮25s，东西红灯亮30s，接下来南北紧示，东西继续 禁行。循环往复，实现交通灯的控制。数码管精确显示信号灯持续时间。 遇到紧急情况时，按下按钮一，东西方向通行，南北禁行。按下按钮二，南北方向通行，东西禁行。-The basic state of this process simulation traffic light control, when the program starts to work, the north and south, east and west road lights are red, For 5 s, as a buffer time.After that, things, things green light 25 s, north and south turns red, 30 s, the next thing tight,

North and south continue to ban.Later, north and south, north and south green light 25 s, something turns red, 30 s, the north and south tight, things continue For stop.Cycling, realize the control of traffic lights.Digital tube precise display lights last time. In case of emergency, press the button a, east-west, north-south ban.Press the button 2, north and south direction, stop.