基于VHDL的等精度测频方法，等精度测频方法是在直接测频的基础上，其闸门时间不是固定的值，而是被测信号周期的整数倍，即与被测信号同步的测频方法。-VHDL-based method of equal precision frequency measurement, and other precision frequency measurement method is based on the direct frequency measurement, the gate time is not a