说明：  文档里面的程序是用VHDL编程的分频程序，是将12MHZ的频率分频为1HZ和1KHZ，当然，也可以修改成任意频率的分频程序。
(Document inside the program is programmed with VHDL frequency division program, is the frequency of 12MHZ frequency is 1HZ and 1KHZ, of course, can also be modified to any frequency frequency program.)