做的等精度频率计，采用等精度测量原理，即利用双计数器“相关计数”和“硬件同步分频”实现高低频率的等精度的测量。用FPGA实现频率测量、周期测量、时间间隔测量、相位测量及脉冲宽度的测量。所有的测量功能都由VHDL语言编程实现。-I do other precision frequency meter, use and other precision measuring principle, namely the use of dual-counter " related counts"　and " hardware synchronization frequency"　to achieve such high and low frequency accuracy of the measurement. FPGA Implementation with frequency measurement, period measurement, time interval measurement, phase measurement and pulse width measurement. All the measurements by the VHDL language programming.