资源描述:
《第2章微处理器及其结构》由会员上传分享,免费在线阅读,更多相关内容在工程资料-天天文库。
1、CHAPTER2TheMicroprocessoranditsArchitecture(P.48)2-1InternalMicroprocessorArchitecture厂>ssadderAHALBHBLCHCLDHDLSPBFDISIfnstructionpointerSegmentregisterscsDSSSLESIFTemporaryregisteALU&OFDFIFTFSFZFATFFuomrnunicatTonregisterFlagreaister1514:EU;Control•circ
2、uitsBusinterfaceunit(BIU)1―W98Executionunit(EU)123451InstructionstreamqueueCFBuscontrolcircuits:Outer・buses2-1-1TheProgrammingmodel(P.48)0-bitnamesFlGURE2-1TheprogrammingModeloftheIntel8086throughthePentiumIINotes:1.TheshadedareasregistersExistonlyonthe8
3、0386throughThePentiumII.EAXAHTAX
4、ALEBXBHIBXBLECXCHexCLEDXDMDXDLESPSPEBPBPEDIDIESISIEIPIPEFLAGSFLAGS32-bit/16-bitnames(namesAccumulatorBaseindexCountDataStackpointerBasepointerDestinahonindexSourceindexInstructionpointerFlags2.Thearchitectureofthe8086thro
5、ugh80286arefullyupward-Compatibletothe80386throughthePentiumII.MultiourooseReaisters■ThemultipurposeregistersineludeEAX,EBX,ECX,EDX,EBP,EDI5andESI.Theseregistersholdvariousdatasizes(bytes,words,ordoublewords)andareusedforalmostanypurpose,asdictatedbyapro
6、gram.umulator,累加器)■Theaccumulatorisusedforinstructionssuchasmultiplication,division,andsomeoftheadjustmentinstructions.EBX(baseindex,基址寄存器)■TheEBXregistersometimesholdstheoffsetaddressofalocationinthememorysystem.ECX(count,计数寄存器)■ECXholdsthecountforvario
7、usinstructions.EDX(data,数据寄存器)■EDXholdsapartoftheresultfromamultiplicationorpartofthedividendbeforeadivision.EBP(basepointer,基指针寄存器)■EBPpointstoamemorylocationformemorydatatransfers.EDI(destinationindex,目标变址寄存器)■EDIoftenaddressstringdestinationdataforthe
8、stringinstructions.ESI(sourceindex,源变址寄存器)■ESIoftenaddressessourcestringdataforthestringinstructions.Special-purposeRegisters■Thespecial-purposeregistersineludeElP,ESP,EFLAGS,andthesegmentregistersCS,DS,ES,SS,FS,andGS.EIP(instructionpointer,扌旨令]指针寄存器)■El
9、Paddressesthenextinstructioninasectionofmemorydefinedasacodesegment.Theinstructionpointer,whichpointstothenextinstructioninaprogram,isusedbythemicroprocessortofindthenextsequentialinstructioninaprogramlocatedwithinthecodes