用verilog实现的一个频率计数器，可分别在不同的频率下计数（自己设定），里面有几个有用的小模块，分频，计数，显示，同步，进位等-Verilog to achieve a frequency counter, respectively, in different frequency count (set), there are several useful modules, divide, count, display, synchronization, binary, etc.