PAGE\*MERGEFORMAT26摘要EDA技术的发展，改变了传统的电子设计方法。FPGA等大规模可编程逻辑器件的广泛应用，使电子设计变得和软件编程一样方便快捷。电子设计技术的进步，也改变了传统频率计的设计方法。常用的频率测量方法既有模拟的利用电路频率特性测量频率的方法，又有利用脉冲计数测量频率的数字方法。随着数字电路技术的发展，以脉冲计数法为基础衍生出各种改进型的数字测频方法，在测量精度、测量响应的快速性等方面都有了很大提高。简易数字频率计的设计，采用FPGA实现对对外来信号采样，运用VHDL在FPG/CPLD器件上实现一种数字频率计测频系统，其在单位时间内通过计数器的累加实现对频率的计数。分析了数字频率计软件构成结构，并对其中的测频控制信号发生器电路进行了VHDL软件编程实现。该设计实现的频率精度为1Hz，测量范围为0～100MHz，经实际电路测试，仿真结果表明，该频率计具有较高的实用性和可靠性。VHDL程序通过综合、适配后形成配置文件，下载到FPGA器件中对FPGA进行配置，使FPGA成为实用的测频模块。通过modelsim波形仿真，符合本次设计的要求。最后，通过完整编译后的pof文件固化到开发板，接上高频信号源，实现了数字频率计的设计。关键词：数字频率计；频率测量；EDA；FPGA；VHDL语言；配置器件AbstractDevelopmentofEDAtechnologyhaschangedthetraditionalelectronicdesignmethods.Widelyusedinlarge-scaleFPGAandotherprogrammablelogicdevices,electronicdesignandsoftwareprogrammingbecomesaseasyandquick.Advancesinelectronicdesigntechnology,butalsochangedthetraditionalfrequencymeterdesign.Existingconventionalfrequencymeasurementmethodusinganalogfrequencycharacteristicsofthemeasuredfrequencyofthecircuit,butalsotheuseofadigitalpulsecountingfrequencymeasurementmethod.Withthedevelopmentofdigitalcircuittechnologytopulsecountbasedonthelawderivedfromavarietyofimproveddigitalfrequencymeasurementmethod,measurementaccuracy,fastresponsemeasurementandotheraspectshavebeengreatlyimproved.Simpledigitalfrequencymeterdesign,FPGAisusedforforeignsignalsampling,useVHDLtoachieveadigitalfrequencymeterfrequencymeasurementsystemontheFPG/CPLDdevices,whichinunittimetoachievefrequencycountedbythecounteraccumulation.AnalysisofthedigitalfrequencymetersoftwarecompositionstructureandoneofthefrequencymeasurementcontrolsignalgeneratorcircuitwereVHDLsoftwareprogramming.Frequencyaccuracyofthedesignandimplementationof1Hz,measurementrangeis0~100MHz,throughtheactualcircuittest,simulationresultsshowthatthefrequencymeterwithhighavailabilityandreliability.VHDLprogramthroughanintegrated,formingadapterconfigurationfile,downloadtoFPGAdevicesconfiguredforFPGA,FPGAmakeapracticalfrequencymeasurementmodule.Bymodelsimwaveformsimulat