基于FPGA的等精度频率计设计

I基于FPGA的等精度频率计设计摘要频率计是实验室和科研、生产中最常用的测量仪器之一。本文介绍了一种基于FPGA芯片设计的等精度频率计。对传统的等精度测量方法进行了改进，采用SOPC设计技术和基于NIOSII嵌入式软核处理器的系统设计方案，通过在FPGA芯片上配置NIOSII软核处理器进行数据运算处理，利用液晶显示器对测量的频率进行实时显示，可读性好。整个系统在一片FPGA芯片上实现，系统测量精度高，实时性好，具有灵活的现场可更改性。本频率测量仪是以Altera公司生产的CycloneII系列EP2C35F672C6器件为核心实现高精度计数功能。整个电路采用模块化设计，调试制作方便。经过仿真并下载验证，能够实现等精度测频功能，频率测量范围为1HZ--200MHZ。关键词：等精度，频率计，FPGA，SOPC，NiosIIIIDesignofEqualPrecisionFrequencyMeterBasedonFPGAABSTRACTFrequencymeterisoneofthemostcommonlyusedmeasuringinstrumentswhichcanbeusedinlaboratory,scientificresearchandproduction.AnequalprecisionfrequencymeterdesignedwithFPGAisintroducedinthisarticle.ItadoptsVery-High-SpeedIntegratedCircuitHardwareDescriptionLanguagetoimplementfunctionmoduleinfrequencymeterbaseontraditionalfrequencymeasurement.SOPCdesigningtechniqueandsystemdesigningplanbasedonNiosIIsoftcoreCPUareusedinthedesign.ItalsoadoptsNiosllsoftcoreCPUasdataprocessingunit,usesLCD1602equipmenttodisplayfrequencyinreal-time.ThewholesystemisintherealizationofaFPGAchip.Soithasahigh-precisionmeasurement,real-timeandflexiblechangeofscene.ThefrequencymeterisbasedonCycloneIIEP2C35F672C6Alteradeviceasthecoretoachievehigh-precisioncounting.Becauseofthemodulardesignofthiscircuit,itisfacilitatetodebug.Afterthesimulation,anddownloadstheconfirmation,canrealizeequal-precisionfrequencymeasurementfunction.Frequencymeasurementscopeis1--200MHZ.KEYWORDS：equalprecisionmeasurement,frequencymeter,FPGA,SOPC,NiosIIIII目录摘要.........................................................................................................................................IABSTRACT..............................................................................................................................II1绪论........................................................................................................................................11.1课题提出的背景..........................................................................................................11.2课题选择意义..............................................................................................................12EDA及其开发平台简介........................................................................................................32.1EDA的具体开发流程..................................................................................................32.1.1设计输入.............................................................................................................32.1.2综合.....................................................................................................................32.1.3适配....................................................................................................................42.1.4仿真....................................................................................................................42.1.5编程下载和硬件测试........................................................................................42.2简介NIOSIIIDE.........................................................................................................42.2.1工程管理器.........................................................................................................52.2.2编辑器和编译器................................................................................................62.2.3调试器.................................................................................................................62.2.4闪存编程器.........................................................................................................73课题方案选择........................................................................................................................83.1频率测量方案选择......................................................................................................83.1.1直接测频法........................................................................................................83.1.2间接测频法........................................................................................................83.1.3等精度测频........................................................................................................93.2基于单片机的测频方案............................................................................................103.3基于FPGA的测频方案............................................................................................114基于FPGA等精度频率计的单元模块设计......................................................................134.1放大整形模块设计....................................................................................................134.2标准信号产生模块设计............................................................................................144.3FPGA芯片模块设计..................................................................................................144.3.1D型触发器的设计...........................................................................................154.3.2计数器的设计..................................................................................................164.3.3锁存器的设计..........................................................