状态机的描述，基于EasyFPGAv1.04 用状态机描述流水灯，状态机在1s的周期下流水灯，方向又sel控制-Descr iption of state machine, based on the state machine described by EasyFPGAv1.04 water lights, state machine at the cycle 1s under water lights, direction and control of sel