LED流水灯工作，Altera FPGA控制LED灯，编程使用Verilog语言，控制六个流水灯-6 LEDs,control by FPGA

控制开发板上的4个LED灯，计数器记到4秒清零，控制LED灯依次亮(Controlling the four leds on the development board, the counter down to the 4 seconds reset, the control the LED light in turn)