格雷码转自然码的VHDL实现，代码是我经过仿真以后可以用的。-natural Gray code to the VHDL code, the code is after I read the simulation can be used.

用VERILOG写的VGA显示代码，经本人调试确定可以正常运行-VERILOG written with VGA display code, as I confirmed to be the normal operation of debugging