一个用verilog编写的数字频率计，利用FPGA实现计数功能，其中使用的测周法。-A written with verilog digital frequency meter, use FPGA implementation counting function, wherein the measured circumference method to use.

实现了利用verilog在FPGA系统上实现的数字频率计，三个档位可供选择。(The digital frequency meter implemented on the FPGA system by Verilog is realized, and three files can be selected.)