该设计严格按照现实中的交通灯设计，利用vhdl硬件描述语言实现，设计一个交通信号灯控制器，由一条主干道和一条支干道汇合成十字路口，在每个入口处设置红、绿、黄三色信号灯，红灯亮禁止通行，绿灯亮允许通行，黄灯亮则给行驶中的车辆有时间停在禁行线外。

2、 红、绿、黄发光二极管作信号灯，。

3、 主干道处于常允许通行的状态，支干道有车来时才允许通行。主干道亮绿灯时，支干道亮红灯；支干道亮绿灯时，主干道亮红灯。

4、 主、支干道均有车时，两者交替允许通行，主干道每次放行45秒，支干道每次放行25秒，设立45秒、25秒计时、显示电路。

5、 在每次由绿灯亮到红灯亮的转换过程中，要亮5秒黄灯作为过渡，使行驶中的车辆有时间停到禁行线外，设立5秒计时、显示电路。

-The design is in strict accordance with the reality of the traffic light design using vhdl hardware descr iption language, a traffic signal controller design, consists of a main road and branch roads merge into a crossroads at the entrance to each set of red, green and yellow color lights, red light no-go, the green light to allow passage, the yellow light to travel in a vehicle parked in the time to cut the line off-line.

2, red, green and yellow LEDs for lights.

3, the main road in the normally allows passage of state, branch roads to car traffic is permitted. A green light when the main road, branch roads red　green light when the branch roads, main roads red.

4, the main, branch roads are car, alternating between the two to allow access, trunk release every 45 seconds, every branch roads clearance 25 seconds, and the establishment of 45 seconds, 25 seconds chronograph, the display circuit.

5, each time by a green light to red light conversion process, to bright yellow as a trans