嵌入式系统架构软体设计课程介绍嵌入式系统产品设计流程概观RISC精简指令集vs.CISC复杂指令集MUO一个简单的处理器MUO指令集与资料路径指令执行范例运算范例练习：MUO微处理器的运算ARM7TDMI资料流ARM的暂存器ProgramStatusRegisterProgramcounter–R15LinkRegister–R14OtherRegisterR0-R13StructureofARMAssemblyLanguageModuleCallingSubroutinesUsesBLCallingSubroutinesExampleConstantDataTypesAlmostallARMinstructionscanbeconditionallyexecuted.e.g.ADDSr0,r1,r2ADDEQr0,r1,r2ExecuteiftheN,Z,CandVflagsintheCPSRsatisfyaconditionspecifiedintheinstruction,otherwise,NOP.AlmosteveryARMinstructioncanbeexecutedconditionallyonthestateoftheALUstateflagsintheCPSR.AddanSsuffixtoanARMdataprocessinginstructiontomakeitupdatetheALUstateflagsintheCPSRE.g.ADDSr0,r1,r2;r0=r1+r2andupdateALUstatusinCPSR.InARMstate,youcan:updatetheALUstatusflagsinthePSRontheresultofadataoperationexecuteseveralotherdataoperationwithoutupdatingtheflagsexecutefollowinginstructionsornot,accordingtothestateoftheflagsupdatedinthefirstoperation.InThumbstatemostdataoperationsalwaysupdatetheflagsandconditionalexecutioncanonlybeachievedusingtheconditionalbranchinstruction(B).DonotusetheSsuffixwithCMP,CMN,TST,orTEQ.ThesecomparisoninstructionsalwaysupdatetheflagALUStatusRegisterinCPSRConditionalCodeSuffixesConditionalCodeExamplesWriteEfficientandsmallsizeCodebyConditionalInstructionExerciseARMADS1.2ImplementationIntegrationPre-configuredProjectStationaryFilesPossibleDevelopmentEnvironmentReferenceARM指令集特点Thumb指令集JazelleARM指令集分类BranchinstructionsBranchInstructionEncodingBranchinstructionsexampleData-processinginstructionsEncodingDataProcessingOpodeExampleData-processingInstructionsExampleData-processingInstructions(cont.)ShifterShifterApplicationsMultiplyinstructionbinaryencodingAssemblyFormat:CLZ{<cond>}{S}Rd,RmSetsRdtothenumberofthebitpositionofhrmostsignificant1inRm.IfRm=0Rd=32.E.g.MOVr0,#&100CLZr1,R0r1=8练习SingleWordandUnsignedByteDataTransferInstructionBinaryEncodingLoadandStoreExamplesHalf-wordandSignedByteDataTransferInstructionBinaryEncodingHalf-wordLoad/StoreExample练习：字串复制MultipleRegist