用HDL语言编写彩灯控制程序：

用状态机实现一个循环彩灯控制器，该控制器控制红、绿、黄三个发光管循环发亮，要

求红发光管亮2秒，绿发光管亮3秒，黄发光管亮1秒。程序所用时钟的频率为1HZ。-Lantern with HDL language control program: A state machine to achieve a circular lantern controller that controls red, green, yellow three LED lights cycle to require red LED light 2 seconds, green LED light 3 seconds, 1 second yellow LED light. Procedures used by the clock frequency of 1HZ.