在对三种测频方法进行分析的基础上，介绍了基于EDA技术的等精度测频原理。给出采用AT89C51实现控制并通过FPGA来设计多功能等精度数字频率计的具体方法。该频率计可以兼顾频率计对速度、资源和测频精度等各方面的优化需求。-Frequency of three methods of analysis based on EDA technology based on the principle of frequency measurement accuracy, etc.. AT89C51 given the use of control and, through multi-FPGA design, such as precision digital frequency of specific methods. Can take into account the frequency meter frequency meter speed, resources, and precision frequency measurement to optimize all aspects of demand.