电子信息工程专业专业英语三千字翻译Word文件下载.docx

电子信息工程专业专业英语三千字翻译Word文件下载.docx

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电子信息工程专业专业英语三千字翻译@#@Unit3computerarchitectureandmicroprocessors@#@3--1ComputerArchitecture@#@1）Computerarchitecture,incomputerscience,isageneraltermreferringtothestructureofallorpartofcomputersystem.Thetermalsocoversthedesignofsystemsoftware,suchastheoperatingsystem（theprogramthatcontrolsthecomputer）,aswellasreferringtothecombinationofhardwareandbasicsoftwarethatlinksthemachinesonacomputernetwork.Computerarchitecturereferstoanentirestructureandtothedetailsneededtomakeitfunctional.Thus,computerarchitecturecoverscomputersystems,microprocessors,circuits,andsystemprograms.Typicallythetermdoesnotrefertoapplicationprograms,suchasspreadsheetsorwordprocessing,whicharerequiredtoperformataskbutnottomakethesystemrun.@#@2）1.DesignElements@#@3）Indesigningacomputersystem,architectsconsiderfivemajorelementsthatmakeupthesystem'@#@shardware:

@#@thearithmetic/logicunit,controlunit,memory,input,andoutput.Thearithmetic/logicunitperformsarithmeticandcomparesnumericalvalues.Thecontrolunitdirectstheoperationofthecomputerbytakingtheuserinstructionsandtransformingthemintoelectricalsignalsthatthecomputer'@#@scircuitrycanunderstand.Thecombinationofthearithmetic/logicunitandthecontrolunitiscalledthecentralprocessingunit（CPU）.Thememorystoresinstructionsanddata.Theinputinputandoutputsectionsallowthecomputertoreceiveandsenddata,respectively.@#@4）Differenthardwarearchitecturesarerequiredbecauseofthespecializedneedsofsystemsandusers.Oneusermayneedasystemtodisplaygraphicsextremelyfast,whileanothersystemmayhavetobeoptimizedforsearchingadatabaseorconservingbatterypowerinalaptopcomputer.@#@5）Inadditiontothehardwaredesign,thearchitectsmustconsiderwhatsoftwareprogramswilloperatethesystem.Software,suchasprogramminglanguagesandoperatingsystems,makesthedetailsofthehardwarearchitectureinvisibletotheuser.Forexample,computersthatusetheCprogramminglanguageoraUNIToperatingsystemmayappearthesamefromtheuser'@#@sviewpoint,althoughtheyusedifferenthardwarearchitectures.@#@6）2.ProcessingArchitecture@#@7）Whenacomputercarriesoutaninstruction,itproceedsthroughfivesteps.First,thecontrolunitretrievestheinstructionfrommemory,forexample,aninstructiontoaddtwonumbers.Second,thecontrolunitdecodestheinstructionintoelectronicsignalsthatcontrolthecomputer.Third,thecontrolunitfetchesthedata（thetwonumbers）.Fourth,thearithmetic/logicunitperformsthespecificoperation（theadditionofthetwonumbers）.Fifth,thecontrolunitsavestheresult（thesumofthetwonumbers）.@#@8）Earlycomputersusedonlysimpleinstructionsbecausethecostofelectroniccapableofcarryingoutcomplexinstructionswashigh.Asthiscostdecreasedinthe1960s,morecomplicatedinstructionsbecamepossible.Complexinstructions（singleinstructionsthatspecifymultipleoperations）cansavetimebecausetheymakeitunnecessaryforthecomputertoretrieveadditionalinstructions.Forexample,ifsevenoperationsarecombinedinoneinstruction,thensixofthestepsthatfetchinstructionsareeliminatedandthecomputerspendslesstimeprocessingthatoperation.Computersthatcombineseveralinstructionsintoasingleoperationarecalledcomplexinstructionsetcomputers（CISC）.@#@9）However,mostprogramsdonotoftenusecomplexinstructions,butconsistmostlyofsimpleinstructions.WhenthesesimpleinstructionsarerunonCISCarchitectures,theyslowdownprocessingbecauseeachinstruction--whethersimpleorcomplex--takeslongertodecodeinaCISCdesign.Analternativestrategyistoreturntodesignsthatuseonlysimple,single--operationinstructionsetsandmakethemostfrequentlyusedoperationsfasterinordertoincreaseoverallperformance.Computersthatfollowthisdesignarecalledreducedinstructionsetcomputers（RISC）.@#@10）RISCdesignsareespeciallyfastatthenumericalcomputationsrequiredinscience,graphics,andengineeringapplications.CISCdesignsarecommonlyusedfornon-numericalcomputationsbecausetheyprovidespecialinstructionsetsforhandlingcharacterdata,suchastextinawordprocessingprogram.SpecializedCISCarchitectures,calleddigitalsignalprocessors,existtoaccelerateprocessingofdigitizedaudioandvideosignals.@#@11）3.OpenandClosedArchitectures@#@12）TheCPUofacomputerisconnectedtomemoryandtotheoutsideworldbymeansofeitheranopenoraclosedarchitecture.Anopenarchitecturecanbeexpandedafterthesystemhasbeenbuilt,usuallybyaddingextracircuitry,suchasanewmicroprocessorcomputerchipconnectedtothemainsystem.Thespecificat