山东理工大学毕业设计(论文)题目:基于CPLD的频率计设计学院:电气与电子工程学院专业:电子信息工程学生姓名:学号:指导教师:毕业设计(论文)时间:二О一三年2月20日~6月8日共16周摘要频率检测是电子领域里最基本的测量,也是最重要的测量。由于频率信号抗干扰能力强、易于传输,可以得到相对较高的测量精度,因此频率测量方法的研究也受到越来越多的关注。基于传统测频原理的频率计的测量精度将随被测信号频率的下降而降低,本次设计中共提出了四种设计方案,通过论证最终决定用等精度的测量方法来完成本次频率计的设计。在本次设计中选择AT89C51单片机和CPLD的结合来实现。其中单片机完成整个测量电路的测试控制、数据处理和显示输出;CPLD主要完成频率测量功能,频率的测量范围在1HZ—1MHZ之间,其中测量误差在1HZ;键盘信号由AT89C51单片机进行处理,它从CPLD读回计数数据并进行运算,向显示电路输出测量结果;显示器电路采用5段LED动态显示,由1个74HC138译码器和74HC573锁存器驱动5个数码管。关键词:频率计,EDA技术,CPLD,单片机,等精度测量AbstractFrequencydetectionisthemostbasicintheelectronicsfieldmeasurement,whichisthemostimportantmeasurement.Duetofrequencysignaltransmission,stronganti-jammingcapability,easycangetrelativelyhighmeasurementprecision,sofrequencymeasurementmethodsofresearchhavealsobeenmoreandmoreattention.Basedonthetraditionalprincipleoffrequencymeterfrequencymeasurementaccuracywillbealongwiththedeclineofthemeasuredsignalfrequencyisreduced,thedesignofthecommunistpartyofChinaputsforwardfourkindsofdesignscheme,throughtheargumentfinallydecidedtouseequalprecisionmeasurementmethodtocompletethedesignoffrequencymeter.InthisdesignchoosethecombinationoftheAT89C51single-chipmicrocomputerandCPLDtoimplement.Thesingle-chipmicrocomputercontrol,theentiremeasurementcircuittestdataprocessinganddisplayoutput;CPLDmaincompletefrequencymeasurementfunction,frequencyofmeasurementrangebetween1hzto1MHZ,whichmeasurementerrorin1hz;Keyboardsignalsareprocessedusingsingle-chipcomputerAT89C51,itreadbackfromCPLDcountdataandcalculation,themeasurementresultstodisplaycircuitoutput;5LEDdynamicdisplay,displaycircuitusedby1,74hc138decoderand74hc573latchdrivefivedigitaltube.KeyWords:frequencymeter,EDAtechnologythe,CPLDandsinglechipmicrocomputer,suchasprecisionmeasurement目录摘要..................................................................IAbstract.............................................................II第一章概述...........................................................1第二章系统设计方案与论证............................................22.1测量原理.......................................................32.1.1直接测频法...............................................32.1.2测周期法.................................................42.1.3倍频法...................................................42.1.4等精度测频法.............................................42.2系统设计指标...................................................62.3系统总体设计框图...............................................6第三章硬件电路设计...................................................83.1系统的组成.....................................................83.2系统的基本工作方式.............................................93.3CPLD测频专用模块..............................................93.3.1CPLD的结构与功能介绍.....................................93.3.2CPLD测频专用模块逻辑设计................................103.3.2.1测频/测周期的实现..................................113.3.2.2控制部件设...