本VHDL源代码由顶层模块、测频模块、驱动模块、计算模块、LCD显示模块、复位模块组成，能精确检测从1--100M频率，误差极小且恒定。-the VHDL source code from the top module, measuring frequency module, driver modules, modules, LCD display module, reduction modules, can be used to accurately detect from 1-- 100M