3 Central Processing Unit.ppt

Unit3CentralProcessingUnit,Aprocessorisafunctionalunitthatinterpretsandcarriesoutinstructions.,WhatIsaProcessor?,Aprocessorisafunctionalunitthatinterpretsandcarriesoutinstructions.处理器是一个解释和执行指令的功能单元。EveryprocessorcomeswithauniquesetofoperationssuchasADD,STORE,orLOADthatrepresenttheprocessorsinstructionset.,Aprocessorisafunctionalunitthatinterpretsandcarriesoutinstructions.处理器是一个解释和执行指令的功能单元。EveryprocessorcomeswithauniquesetofoperationssuchasADD,STORE,orLOADthatrepresenttheprocessorsinstructionset.每一个处理器都有一个诸如ADD、STORE或LOAD之类的独立操作集,这个操作集即该处理器的指令系统。,Computerdesignersarefondofcallingtheircomputersmachines,sotheinstructionsetissometimesreferredtoasmachineinstructionsandthebinarylanguageinwhichtheyarewritteniscalledmachinelanguage.,Computerdesignersarefondofcallingtheircomputersmachines,sotheinstructionsetissometimesreferredtoasmachineinstructionsandthebinarylanguageinwhichtheyarewritteniscalledmachinelanguage.befondof:乐于，喜欢bereferredtoas:被称为,Computerdesignersarefondofcallingtheircomputersmachines,sotheinstructionsetissometimesreferredtoasmachineinstructionsandthebinarylanguageinwhichtheyarewritteniscalledmachinelanguage.befondof:乐于，喜欢bereferredtoas:被称为计算机设计者习惯将计算机称为机器，所以指令集也常被称为机器指令；编写指令所使用的二进制语言则被称为机器语言。,Youshouldconfusetheprocessorsinstructionsetwiththeinstructionsfoundinhigh-levelprogramminglanguages,suchasBASICorC.,Youshouldconfusetheprocessorsinstructionsetwiththeinstructionsfoundinhigh-levelprogramminglanguages,suchasBASICorC.你可能会将处理器的指令系统和高级程序语言（如BASIC或C）中的指令相混淆。Aninstructionismadeupofoperationsthatspecifythefunctiontobeperformedandoperandsthatrepresentthedatatobeoperatedon.,Youshouldconfusetheprocessorsinstructionsetwiththeinstructionsfoundinhigh-levelprogramminglanguages,suchasBASICorC.你可能会将处理器的指令系统和高级程序语言（如BASIC或C）中的指令相混淆。Aninstructionismadeupofoperationsthatspecifythefunctiontobeperformedandoperandsthatrepresentthedatatobeoperatedon.,操作码用于指明要执行的功能；操作数则表示要操作的数据。,指令是由操作码和操作数组成，,Forexample,ifaninstructionistoperformtheoperationofaddingtwonumbers,itmustknowwhatthetwonumbersareandwherethetwonumbersare.例如，指令要执行两个数相加的操作，它必须知道是哪两个数字以及这两个数存放在哪里。Whenthenumbersarestoredinthecomputersmemory,theyhaveaddressestoindicatewheretheyare,soifanoperandreferstodatainthecomputersmemoryitiscalledanaddress.,当数据存在计算机存储器中时，会有相应的地址表明这些数据存储的位置。,所以如果一个操作数指的是计算机存储器中的数据，那么这个操作数被称为地址。,Theprocessorsjobistoretrieveinstructionsandoperandsfrommemoryandtoperformeachoperation.Havingdonethat,itsignalsmemorytosenditthenextinstruction.havingdonethat：指“完成以上操作之后”处理器的工作是从存储器中取出指令和操作数以执行每个操作。Thisstep-by-stepoperationisrepeatedoverandoveragainatawesomespeed.这种按部就班的操作以惊人的速度周而复始地重复着。,取回；挽回；检索,Theprocessorsjobistoretrieveinstructionsandoperandsfrommemoryandtoperformeachoperation.Havingdonethat,itsignalsmemorytosenditthenextinstruction.,向发信号,完成以上操作后，处理器会通知存储器发送下一个指令。,按部就班的；逐步的,让人惊叹的；使人敬畏的,Atimercalledaclockreleasespreciselytimedelectricalsignalsthatprovidearegularpulsefortheprocessorswork.一个被称为时钟的计时器定时地精确地发出电信号，,精确地；严格地；确切地,同步的，定时的，时控的,Atimercalledaclockreleasespreciselytimedelectricalsignalsthatprovidearegularpulsefortheprocessorswork.一个被称为时钟的计时器定时地精确地发出电信号，这些电信号为处理器的工作提供规律的脉冲。Thetermthatisusedtomeasurethecomputersspeedisborrowedfromthedomainofelectricalengineeringandiscalledamegahertz(MHz),whichmeansmillioncyclespersecond.,Atimercalledaclockreleasespreciselytimedelectricalsignalsthatprovidearegularpulsefortheprocessorswork.一个被称为时钟的计时器定时地精确地发出电信号，这些电信号为处理器的工作提供规律的脉冲。Thetermthatisusedtomeasurethecomputersspeedisborrowedfromthedomainofelectricalengineeringandiscalledamegahertz(MHz),whichmeansmillioncyclespersecond.,电气工程,用于衡量计算机速度的术语是从电气工程领域借用来的，称作兆赫(MHz)，,即每秒百万个周期。,MB,兆赫兹,Forexample,inan8-MHzprocessor,thecomputersclockticks8milliontimestoevery1secondtickofanordinaryclock.例如，对于一个8MHz的处理器来说，普通时钟每秒滴答一次，而该计算机时钟则滴答了800万次。Aprocessoriscomposedoftwofunctionalunits-acontrolunitandanarithmetic/logicunit-andasetofspecialworkspacescalledregisters.,Forexample,inan8-MHzprocessor,thecomputersclockticks8milliontimestoevery1secondtickofanordinaryclock.例如，对于一个8MHz的处理器来说，普通时钟每秒滴答一次，而该计算机时钟则滴答了800万次。Aprocessoriscomposedoftwofunctionalunits-acontrolunitandanarithmetic/logicunit-andasetofspecialworkspacescalledregisters.处理器是由两个功能部件和一组称为寄存器的特殊工作空间组成的。,Forexample,inan8-MHzprocessor,thecomputersclockticks8milliontimestoevery1secondtickofanordinaryclock.例如，对于一个8MHz的处理器来说，普通时钟每秒滴答一次，而该计算机时钟则滴答了800万次。Aprocessoriscomposedoftwofunctionalunits-acontrolunitandanarithmetic/logicunit-andasetofspecialworkspacescalledregisters.处理器是由两个功能部件（控制器和算术逻辑运器）和一组称为寄存器的特殊工作空间组成的,1.TheControlUnitThecontrolunitisthefunctionalunitthatisresponsibleforsupervisingtheoperationsoftheentirecomputersystem.控制器是负责监控整个计算机系统操作的功能部件。,监督；管理；指导,Insomeways,itisanalogoustoatelephoneswitch-boardwithintelligencebecauseitmakestheconnectionsbetweenvariousfunctionalunitsofthecomputersystemandcallsintooperationeachunitthatisrequiredbytheprogramcurrentlyinoperation.beanalogousto：类似于，与相似,adj.相似的，可比拟的；,Insomeways,itisanalogoustoatelephoneswitch-boardwithintelligencebecauseitmakestheconnectionsbetweenvariousfunctionalunitsofthecomputersystemandcallsintooperationeachunitthatisrequiredbytheprogramcurrentlyinoperation.beanalogousto：类似于，与相似它在某种程度上类似于智能电话交换机，,电话交换机,Insomeways,itisanalogoustoatelephoneswitch-boardwithintelligencebecauseitmakestheconnectionsbetweenvariousfunctionalunitsofthecomputersystemandcallsintooperationeachunitthatisrequiredbytheprogramcurrentlyinoperation.beanalogousto：类似于，与相似它在某种程度上类似于智能电话交换机，,因为它能在计算机系统的各个功能部件之间进行连接，,Insomeways,itisanalogoustoatelephoneswitch-boardwithintelligencebecauseitmakestheconnectionsbetweenvariousfunctionalunitsofthecomputersystemandcallsintooperationeachunitthatisrequiredbytheprogramcurrentlyinoperation.beanalogousto：类似于，与相似它在某种程度上类似于智能电话交换机，,analog,analog,因为它能在计算机系统的各个功能部件之间进行连接，,Insomeways,itisanalogoustoatelephoneswitch-boardwithintelligencebecauseitmakestheconnectionsbetweenvariousfunctionalunitsofthecomputersystemandcallsintooperationeachunitthatisrequiredbytheprogramcurrentlyinoperation.beanalogousto：类似于，与相似它在某种程度上类似于智能电话交换机，,此处相当于“callseachunitintooperation”，由于后面的定语从句是用于修饰“eachunit”的，所以将“eachunit”放置到后面，变成“callsintooperationeachunit”,并根据当前正在运行的程序的要求，调动各部件进行操作。,Thecontrolunitfetchesinstructionsfrommemoryanddeterminestheirtypeordecodesthem.,Thecontrolunitfetchesinstructionsfrommemoryanddeterminestheirtypeordecodesthem.控制器从内存取出指令，确定指令类型或对其进行译码。Itthenbreakseachinstructionintoaseriesofsimplesmallstepsoractions.然后将每个指令分解成一系列简单的小步骤或动作。Bydoingthis,itcontrolsthestep-by-stepoperationoftheentirecomputersystem.通过这样，它控制了整个计算机系统的每一步操作。,通过这样做,2.TheArithmetic/LogicUnitThearithmetic/logicunit(ALU)isthefunctionalunitthatprovidesthecomputerwithlogicalandcomputationalcapabilities.算术逻辑运算器（即ALU）是为计算机提供逻辑和计算功能的部件。DataarebroughtintotheALUbythecontrolunit,andtheALUperformswhateverarithmeticorlogicoperationsarerequiredtohelpcarryouttheinstruction(SeeFig.3-1).控制器将数据送到ALU中，,然后由ALU执行完成指令所需的算术或逻辑操作（见图3-1）。,2.TheArithmetic/LogicUnitThearithmetic/logicunit(ALU)isthefunctionalunitthatprovidesthecomputerwithlogicalandcomputationalcapabilities.算术逻辑运算器（即ALU）是为计算机提供逻辑和计算功能的部件。DataarebroughtintotheALUbythecontrolunit,andtheALUperformswhateverarithmeticorlogicoperationsarerequiredtohelpcarryouttheinstruction(SeeFig.3-1).控制器将数据送到ALU中，,Arithmeticoperationsincludeadding,subtracting,multiplying,anddividing.Logicoperationsmakeacomparisonandtakeactionbasedontheresults.,Arithmeticoperationsincludeadding,subtracting,multiplying,anddividing.Logicoperationsmakeacomparisonandtakeactionbasedontheresults.算术操作包括加、减、乘、除。逻辑操作则执行比较运算，并根据运算结果进行操作。Forexample,twonumbersmightbecomparedtodetermineiftheyareequal.Iftheyareequal,processingwillcontinues;iftheyarenotequal,processingwillstop.例如，比较两个数是否相等。如果相等，则继续处理；若不相等，则停止处理。,采取行动,3.RegistersAregisterisastoragelocationinsidetheprocessor.Registersinthecontrolunitareusedtokeeptrackoftheoverallstatusoftheprogramthatisrunning.,控制器中的寄存器用于记录运行中的程序的总体状态。,3.RegistersAregisterisastoragelocationinsidetheprocessor.Registersinthecontrolunitareusedtokeeptrackoftheoverallstatusoftheprogramthatisrunning.寄存器是处理器内部的一个存储单元。Controlunitregistersstoreinformationsuchasthecurrentinstruction,thelocationofthenextinstructiontobeexecuted,andtheoperandsoftheinstruction.它存储的信息包括当前运行的指令、下一条要运行的指令的地址，以及指令操作数等。,与保持联系；记录；跟踪,全部的；综合的,IntheALU,registersstoredataitemsthatareadded,subtracted,multiplied,divided,andcompared.Otherregistersstoretheresultsofarithmeticandlogicoperations.在ALU中，寄存器存储用于加、减、乘、除以及比较运算的数据项。其它寄存器则存储算术和逻辑运算的结果。Animportantfactorthataffectsthespeedandperformanceofaprocessoristhesizeoftheregisters.,IntheALU,registersstoredataitemsthatareadded,subtracted,multiplied,divided,andcompared.Otherregistersstoretheresultsofarithmeticandlogicoperations.在ALU中，寄存器存储用于加、减、乘、除以及比较运算的数据项，其它寄存器则存储算术和逻辑运算的结果。Animportantfactorthataffectsthespeedandperformanceofaprocessoristhesizeoftheregisters.影响处理器速度和性能的一个重要的因素就是寄存器容量的大小。,Technically,thetermwordsize(alsocalledwordlength)describesthesizeofanoperandregister,butitisalsousedmorelooselytodescribethesizeofthepathwaystoandfromtheprocessor.,Technically,thetermwordsize(alsocalledwordlength)describesthesizeofanoperandregister,butitisalsousedmorelooselytodescribethesizeofthepathwaystoandfromtheprocessor.从技术上看，术语“字的大小”（也被称为字长）描述了操作数寄存器的大小，,松散地；粗略地；不严格地；,通道；途径,但从非严格意义上来说，它也可以用于描述出入处理器的通道的大小。,Currently,wordsizesingeneral-purposecomputersrangefrom8to64bits.Iftheoperandregistersofaprocessorare16bitswide,theprocessorissaidtobea16-bitprocessor.,Currently,wordsizesingeneral-purposecomputersrangefrom8to64bits.Iftheoperandregistersofaprocessorare16bitswide,theprocessorissaidtobea16-bitprocessor.目前，通用计算机的字长范围从8位到64位不等，如果处理器的操作数寄存器是16位的，则该处理器就被称为16位处理器。EarlyCPUswerecustom-designedasapartofalarger,sometimesone-of-a-kind,computer.早期的CPU都是专门为一台大型的甚至是独一无二的计算机设计的。,专门设计的；定做的,每种只有一个的；独一无二的,However,thiscostlymethodofdesigningcustomCPUsforaparticularapplicationhaslargelygivenwaytothedevelopmentofmass-producedprocessorsthataremadeforoneormanypurposes.,昂贵的；代价高的,However,thiscostlymethodofdesigningcustomCPUsforaparticularapplicationhaslargelygivenwaytothedevelopmentofmass-producedprocessorsthataremadeforoneormanypurposes.但是，这种为某个专门的应用而设计定制CPU的高代价的方式，,让位于；给让路；被取代,很大程度上已经被为了某个或多个目的而大量生产CPU的发展趋势所取代。,application,Thisstandardizationtrendgenerallybeganintheeraofdiscretetransistormainframesandminicomputersandhasrapidlyacceleratedwiththepopularizationoftheintegratedcircuit(IC).,Thisstandardizationtrendgenerallybeganintheeraofdiscretetransistormainframesandminicomputersandhasrapidlyacceleratedwiththepopularizationoftheintegratedcircuit(IC).这种标准化的趋势始于分离式晶体管大型机和小型机的时代，,分立式晶体管,加快；增速,普及,并随着集成电路(IC)的普及加速发展。,Thisstandardizationtrendgenerallybeganintheeraofdiscretetransistormainframesandminicomputersandhasrapidlyacceleratedwiththepopularizationoftheintegratedcircuit(IC).TheIChasallowedincreasinglycomplexCPUstobedesignedandmanufacturedtotolerancesontheorderofnanometers.,制造；生产,并制造至纳米级公差。,Thisstandardizationtrendgenerallybeganintheeraofdiscretetransistormainframesandminicomputersandhasrapidlyacceleratedwiththepopularizationoftheintegratedcircuit(IC).TheIChasallowedincreasinglycomplexCPUstobedesignedandmanufacturedtotolerancesontheorderofnanometers.集成电路使得日益复杂的CPU得以设计,属于一类的,纳米,趋势,限度；公差；,BoththeminiaturizationandstandardizationofCPUshaveincreasedthepresenceofthesedigitaldevicesinmodernlifefarbeyondthelimitedapplicationofdedicatedcomputingmachines.,小型化，微型化,标准化,BoththeminiaturizationandstandardizationofCPUshaveincreasedthepresenceofthesedigitaldevicesinmodernlifefarbeyondthelimitedapplicationofdedicatedcomputingmachines.CPU的微型化和标准化使其越来越多地出现在现代生活的数码设备中，Modernmicroprocessorsappearineverythingfromautomobilestocellphonesandchildrenstoys.现代微处理器出现在从汽车到手机、儿童玩具每件事物中。,大量超出,专用的,而不再仅仅局限于专业计算机中的应用。,Answerthefollowingquestionsaccordingtothetext:1.Whyisthebinarylanguagecalledmachinelanguage?2.Whatdoesaninstructionconsistof?3.Whatisaprocessorcomposedof?4.Whatsthefunctionofthecontrolunit?5.Whatsthefunctionofthearithmetic/logicunit?,1.Becausecomputerdesignersarefondofcallingtheircomputersmachines,sotheinstructionsetissometimesreferredtoasmachineinstructionsandthebinarylanguageinwhichtheyarewritteniscalledmachinelanguage.2.Aninstructionconsistsofoperationsandoperands.3.Aprocessoriscomposedoftwofunctionalunits-acontrolunitandanarithmetic/logicunit-andasetofspecialworkspacescalledregisters.4.Thecontrolunitisthefunctionalunitthatisresponsibleforsupervisingtheoperationoftheentirecomputersystem.5.Thearithmetic/logicunit(ALU)isthefunctionalunitthatprovidesthecomputerwithlogicalandcomputationalcapabilities.,II.Matchthefollowingtermstotheappropriatedefinition:1._Processor2._Instructionset3._Clock4._Machinela