基于CPLD的交通信号灯的实现，使用VHDL语言，使用不同颜色的二极管分别代表红黄绿三种信号灯。在数码管上可以分别显示倒计时。-CPLD-based implementation of the traffic lights, the use of VHDL language, using different colors of red yellow and green diodes representing three kinds of lights. On the digital countd