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1、8086、8088汇编指令系统(Assemblyinstructionsystemof8086and8088)18086/8088instructionsystemThe8086/8088commandsystem1.Datatransferinstructions1.GeneraldatatransferinstructionsMOV(Move)transmissionPUSHontothestackPOPfromthestackXCHG(Exchange)Exchange.MOVinstructionThef
2、ormatis:MOVDST,SRCOperation:(DST)<-(SRC).PUSHtostackinstructionTheformatis:PUSHSRCOperation:(SP)<-(SP)-2((SP)+1(SP))<-(SRC).popoutstackinstructionTheformatis:POPDSTOperationoperation:(DST)<-((SP+1),(SP))(SP)<-(SP)+2.xchgexchangeinstructionsFormat:XCHGOPR1,OPR
3、2Operation:(OPR1)<->(OPR2)2.Specialtransmissioninstructionsforaccumulator(Input)INtheInputTheOUTOutput(Output)XLAT(Translate)escapeThissetofinstructionsislimitedtousingtheaccumulatorAXorALtotransmitinformation.INinputinstructionLongformat:INAL,PORT(byte)INAX,
4、PORT(words)Operation:(AL)<-(PORT)(bytes)(AX)<-(PORT+1,PORT)(words)Shortformat:INAL,DX(bytes)INAX,DX(words)Operation:AL<-((DX))(byte)AX<-(DX(DX)+1)(words).outoutputinstructionLongformat:OUTPORT,AL(byte)TheOUTPORT,AX(words)Operation:(PORT)<-(AL)(bytes)(thePORT+
5、1,PORT)<-(AX)(words)Shortformat:OUTDX,AL(byte)TheOUTDX,AX(words)Operationtobeperformed:((DX))<-(AL)(bytes)((DX)+1,(DX))<-AX(words)INIBM-PC,externaldevicescanhaveupto65536I/OPORT,PORT(i.e.peripheralsPORTaddress)of0000~FFFFH.Thetop256ports(0~FFH)canbespecifiedI
6、Ntheinstructiondirectly,thisisthelongformatofthePORT,themachineinstructionwithtwobytes,saidthesecondbyteisthePORTnumber.SowhenusingalongformatcanbespecifieddirectlyINthespecifiedPORTnumber,butonly256portsbefore.WhenthePORTnumber>=256,canonlyusetheshortformat,
7、atthispoint,youmustfirstputthePORTnumberINtheDXregisters(PORTnumberfrom0000to0FFFFH),thenuseINorOUTinstructionstotransmitinformation.XLATchangecommandFormat:XLATOPROr:XLATOperation:(AL)<(BX)+(AL))3.EffectiveaddresstosendregisterinstructionTheLEA(Loadeffective
8、address)validaddresstosendtheregisterTheLDS(LoadDSwithPointer)PointersendsregistersandDSTheLoadESwithPointersendsregistersandES.LEAeffectiveaddressdeliveryregisterTheformatis:LEAREG,SRCOp