文档介绍：Lecture4:DataTransfer,Addressing,andArithmeticAssemblyLanguageforIntel-puters,-relatedOperatorsandDirectivesIndirectAddressingJMPandLOOPInstructionsDataTransferInstructionsOperandTypesImmediateoperands(imm):ThedataisaconstantRegisteroperands(reg):Thedataitemisinaregister ---(mem):Thedataitemisinmemory----99fordetailsDataTransferInstructionsMOVInstructionCopiesdataGeneralformatMOVdestination,sourceFormats-legaloperands MOVreg,reg MOVreg,mem MOVmem,reg MOVreg,immed MOVmem,immedimmedmeansaconstantSourceanddestinationmusthavethesamesize"reg"canbeanyregisterexceptDoesnotchangeflagNote:MemorytomemorymovesarenotallowedDataTransferInstructionsMOVInstructionRulesIPSegmentregistersusespecialrules -tobeusedonlywhentheprogramrunsinrealmode -CScannotbeatargetoperand - bValdb20 wValdw0AAAAh dValDWORD0FEDCBA09h .code … movAL,10 movEAX,10 movBX,wVal movdVal,ECX;.386required movCX,bVal movDH,1234;illegal;illegalImmediateoperandsdonothavealengthattributeDataTransferInstructionsZero/SignExtensionofIntegersMOVZXInstructionMOVSXInstructionCopiesthecontentsofasourceoperandintoadestinationoperandandzero-extendsthevaluetoeither16or32bitsOnlyusedwithunsignedintegersCopiesthecontentsofasourceoperandintoadestinationoperandandsign-extendsthevaluetoeither16or32bitsOnlyusedwithsignedintegersDataTransferInstructionsZero/ bValdb20 wValSWORD8AAAh dValDWORD0FEDCBA09h .code … movAL,bVal movBX,wVal movzxECX,AL movSXEDX,wVal movSX,EAX,1234ECX=?EDX=?Anythingwrong?DataTransferInstructionsXCHGInstructionXCHGexchangesthecontentsofsourceanddestingationFormat xchgreg,reg xchgreg,mem xchgmem,regExamples:xchgAX,BX xchgAH,bData xchgwData,CXmov'srulesapply,doesnotchangeflagsDataTransferInstructionsLAHFandSAHFInstructionsLAHFSAHFCopiesthelowbyteoftheEFLAGSregisterintoAHExample