外文文献翻译基于单片机的频率计设计本科学位论文Word下载.docx

外文文献翻译基于单片机的频率计设计本科学位论文Word下载.docx

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外文文献翻译基于单片机的频率计设计本科学位论文@#@原文:

@#@@#@ThisdesigntakeatMCS-51monolithicintegratedcircuitasthecorefullusehardwaresourcedesign'@#@sonekindoffrequencymeter,thisfrequencymeterwillbemeasuredfirstthatsignalenlargementreshapingprocessing,turnssatisfiesTTL/whichthemonolithicintegratedcircuitI/OmouthacceptstheCMOScompatiblesignalfrommonolithicintegratedcircuit'@#@sT1inputportinputdirectsummationpulsenumber,themonolithicintegratedcircuitinteriortimerfixedtimeis1S,bynowaccumulatedthepulsenumbernamelyforismeasuredthesignalthefrequency.Finallypassesthroughmonolithicintegratedcircuitprocessingtodelivertothelcdliquidcrystaldisplaymonitordemonstration.@#@CentralProcessingUnitDesigns@#@TheCPUisthekeycomponentofadigitalcomputer.Itspurposeistodecodeinstructionreceivedfrommemoryandperformtransfers,arithmetic,logic,andcontroloperationswithdatastoredininternalregisters,memory,orI/Ointerfaceunits.Externally,theCPUprovidesoneormorebusesfortransferringinstructions,data,andcontrolinformationtoandfromcomponentsconnectedtoit.Inthegenericcomputeratthebeginningofchapter1,theCPUisapartoftheprocessorandisheavilyshaded.CPUs,however,mayalsoappearincomputers.Small,relativelysimplecomputerscalledmicrocontrollersareusedincomputersandinotherdigitalsystemstoperformlimitedorspecializedtasks.Forexample,amicrocontrollerispresentinthekeyboardandinthemonitorinthegenericcomputer;@#@thus,thesecomponentsarealsoshaded.Insuchmicrocontrollers,theCPUmaybequitedifferentfromthosediscussedinthischapter.Thewordlengthsmaybeshort（say,fouroreightbits）,thenumberofregisterssmall,andtheinstructionsetslimited.Performanee,relativelyspeaking,ispoor,butadequateforthetask.Mostimportant,thecostofthesemicrocontrollersisverylow,makingtheirusecosteffective.@#@Inthefollowingpages,weconsidertwocomputerCPUs,oneforacomplexinstructionsetcomputer（CISC）andtheotherforareducedinstructionsetcomputer（RISC）.Afteradetailedexaminationofthedesigns,wecomparetheperformaneeofthetwoCPUsandpresentabriefoverviewofsomemethodsusedtoenhancethatperformanee.Finally,werelatethedesignideasdiscussedtogeneraldigitalsystemdesign.@#@1、Thecomplexinstructionsetcomputer@#@Thefirstdesignwepresentisforacomplexinstructionsetcomputerwithanon-pipelineddatapathandmicroprogrammedcontrolunit.Webeginbydescribingtheinstructionsetarchitecture,includingtheCPUregisterset,instructionformats,andaddressingmodes.The@#@CISCnatureoftheinstructionsetarchitectureisdemonstratedbyitsmemory-to-memoryaccessfordatamanipulationinstructions,eightaddressingmodes,twoinstructionformatlengths,andinstructionsthatrequiresignificantsequencesofoperationsfortheirexecution.@#@WedesignadatapathforimplementingtheCISCarchitecture.ThedatapathisbasedontheoneinitiallydescribedinSection7-9andincorporatedintoaCPUinsection8-10.modificationsaremadetotheregisterfile,thefunctionunit,andthebusestosupportthepresentinstructionsetarchitecture.@#@Oncethedatapathhasbeenspecified,acontrolunitisdesignedtocompletetheimplementationoftheinstructionsetarchitecture.Thedesignofthecontrolunitmustinvolveacoordinateddefinitionofboththehardwareorganizationandthemicroprogramorganization.Inparticular,dividingthemicroprogramintomicroroutines,whileatthesametimedesigningthesequencerwithwhichtheyinteract,isakeypartofthedesign.Eventheinstructionfieldsandopposedaretiedtothiscoordinatedeffort.Followingthedefinitionofthehardwareandmicrocodeorganizations,wedetailessentialpartsofthemicrocodeandthemicroroutinesforrepresentativeoperations.@#@Instructionsetarchitecture@#@Figure10-1showstheCISCregistersetaccessibletotheprogrammer.Allregistershave16bits.Theregisterfilehaseightregisters,ROthoughR7.R0isaspecialregisterthatalwayssuppliesthevaluezerowhenitisusedasasourceanddiscardstheresultwhenitisusedasadestination.@#@□FIGURE10-1@#@CPURegisterDiagrGmForCISC@#@Inadditionaltotheregisterfile,thereisaprogramcounterPCandstackpointerSP.Thepresenceofastackpointerindicatesthatamemorystackisapartofthearchitecture.thefinalregisteristheprocessorstatusregistePSRwhichcontainsinformationonlyinitsrightmostthefivebits;@#@theremainderoftheregisterisassumedtocontainzero.ThePSRcontainsthefourstoredstatusbitvaluesZ,N,C,andVinpositions3through0,respectively.Inadditional,astoredi