基于FPGA的等精度数字频率计

Equal Precision Digital Frequency Meter Based on FPGA

设计了一种利用等精度测量原理的数字频率计,可以实现对频率、脉宽以及占空比的测量。该频率计主要由自校、测频、测脉宽等模块组成,系统设计时将各个模块集成到现场可编程门阵列(FPGA)芯片内部,采用超高速集成电路硬件描述语言(VHDL)编程,使系统具有良好的可扩展性。通过测量可知,待测频率的测量结果都可以保持不变,而且标频计数只有个位误差,和理论保持一致,说明该频率计能完成预定指标要求。

A digital frequency meter based on equal precision measurement principle is designed,which can measure the frequency,pulse width and duty cycle.The frequency meter is mainly composed of self calibration,frequency measurement,pulse width measurement module,the system design of each module will be integrated into a field programmable gate array(FPGA)chip,using ultra high speed integrated circuit hardware description language(VHDL)programming,the system has good scalability.The measurement results show that the measured frequency can be kept unchanged,and the standard frequency count is only one bit error,consistent with the theory,indicating that the frequency meter can meet the requirements of predetermined indicators.