fpga与pc机的rs232的通信代码，简单全面-the fpga with pc rs232 communication code, simple and comprehensive

用上位机UART控制一个十字路口的交通灯的.v文件。包括testbench在内，可用FPGA cycloneII DE270跑仿真。-traffic lights at a crossroads. V file controlled by PC UART. Including testbench , available FPGA cycloneII DE270 run the simulation.