Speed-UpEstimationfor HW/SW-Systems WolframHardtt,WolfgangRosenstieltt

applications.Severalpartitioningmethodshave been IStheacceleratIOnofthelimecntIca!p ~ oftheapphcatton suggested.Thusthedesignerselectsmodulesfor HW or ~25]. Oth~r a~proachesop.ttilllze a HW/SW-SW-implementationf r the bestpossiblepeiformance Imple~entat~o~.ll1Sleadstoa.d.esIgnofthesamebehavior withina setofperformanceanddesignconstraints.This?utwIth~mmII~l1zedHW-p~tIOn[~O].Thisi~.necessary paperdescribesan estimationmethodto approximatea If thedesIgnenvIronmentrestrIcthesIzeofadditIOnalHW. priori the entiresystempeiformance.The estimation Furtherapproachesarenotconstraintdrivenbutfocusonan methodhasbeenintegratedintothecodesigntoolCODand overallsystemoptimization.Themostimportantaspectis firstresultscouldbegenerated.Theestimatedspeed-uphas thecomputationtimeof thewholeapplication.HW/SW-beendeterminedfor a cipheringalgorithmandhasbeen partitioningcanraisethesystemperfonnancesignificantly comparedtothespeed-upoftheentireHW/SW-system.The andatrade-offbetweenflexibilityandperfonnancecanbe estimationspeed-upmatchesthefinalspeedup. detennined[13,22].Thisis especiallyinterestingbecause 1 I t d t ' standardcomponentsandstandardarchitectureconceptsare. n ro UC IOn '. usedandextendedby specIalpurposecomponentsWhICh areapplicationspecific.But severaleffectsof HW/SW-partitioningmayreducethesystemperfonnance,.g.,data transferbetweenHW- and SW-partitionsare very expensiveandtimeconsuming.Of course,thesecosts dependonthechosenarchitectureaswellasontheHWI SW-partitioningandit is difficultto quantifythereached improvementsconsideringsystemperfonnancea priori becausenotonlytheHW-partitionmustbein viewbutthe Duringthelastdecaderaisingcomputingpowerand complexsynthesistoolsaswellasdecreasingchipsizedue to technologyimprovementslead to a higherlevelof automateddesigncombiningHW-andSW-componentsto HW/SW-systems.It has been pointedout that the partitioningprocessis rathercomplexand different approacheshavebeensuggested[23].Someapproachesu e estimationmethodstocapturetheproblemcomplexity.I