ApplicationReportSPRAAN9–June2007C28xFPUPrimerLoriHeustess.............................................................................................................AECDCS2000ABSTRACTThisprimerprovidesanoverviewofthefloating-pointunit(FPU)intheTMS320F28335,TMS320F28334,andTMS320F28332DigitalSignalController(DSC)devices.Topic..................................................................................................Page1Introduction...............................................................................22Architecture...............................................................................43InstructionSetOverview............................................................104InterruptContextSaveandRestore............................................20SPRAAN9–June2007C28xFPUPrimer1SubmitDocumentationFeedbackwww.ti.com1Introduction1.1Nomenclature1.2WhatistheC28xplusFloatingPointUnit?IntroductionThissectionexplainswhatthefloating-pointunitisandwhyitwasaddedtotheC28x™digitalsignalcontrollers.Thefollowingnomenclatureisusedthroughoutthisdocument:•CPUisthecentralprocessingunit.•TheTMS320C28xfixed-pointcentral-processing-unitisreferredtoasC28xorC28xCPU.•TheTMS320C28xplusfloating-pointCPUisrefereedtoasC28xplusfloating-pointorC28x+FPU.•AFloating-pointinstructionreferstoallinstructionsaddedforfloating-pointsupport.Thisdoesnotincludethefixed-pointCPUinstructionset.ThesearedocumentedinTMS320C28xFloatingPointUnitandInstructionSetReferenceGuide(literaturenumberSPRUEO2).•AC28xstandardinstructionreferstoallinstructionsonthefixed-pointC28xCPU.ThesearedocumentedinTMS320C28xDSPCPUandInstructionSetReferenceGuide(literaturenumberSPRU430).Note:TheC28xfixed-pointCPUisdocumentedinTMS320C28xDSPCPUandInstructionSetReferenceGuide(literaturenumberSPRU430).ThisdocumentalsoappliestotheC28x+FPU.TheextensionstotheC28xtosupportfloating-pointaredocumentedinTMS320C28xFloatingPointUnitandInstructionSetReferenceGuide(literaturenumberSPRUEO2).Thisdocumentshouldbeconsideredasas...
