利用硬件描述语言VHDL设计交通灯电路,设计一个十字路口交通灯控制器，东西、南北方向有红灯、黄灯、绿灯，持续时间分别为45、5、40秒。-use VHDL design of traffic lights at the circuit, the design of traffic lights at a crossroads controller East and West, North-South direction of a red light, yellow light, green light, the duration of 45, morphine seconds.