测试人体视觉的反应时间，可以作为vhdl编程的练习之用，也可以更进一步的开发成为具有商业价值的产品，这里面只是能够实现测试人体视觉反应时间的基本功能的程序-Test of human visual reaction time, can be used as VHDL programming exercises used can also be further developed into products with commercial value, there is only able to