System-on-Chip Network Modeling Style Guide

CenterforEmbeddedComputerSystemsUniversityofCalifornia,IrvineSystem-On-ChipNetworkModelingStyleGuideDongwanShinJunyuPengAndreasGerstlauerRainerD¨omerDanielD.GajskiTechnicalReportCECS-TR-04-23July31,2004System-On-ChipNetworkModelingStyleGuideDongwanShinJunyuPengAndreasGerstlauerRainerD¨omerDanielD.GajskiTechnicalReportCECS-TR-04-23July31,2004CenterforEmbeddedComputerSystemsUniversityofCalifornia,IrvineIrvine,CA92697-3425,USA(949)824-8919owconsistsofaseriesofrenementstepsthatgraduallytransformanabstractspecicationmodelintoanarchitecturemodel,anetworkmodel,acommunicationmodelandnallyadetailedimplementationmodel.Thetransformationscanbeautomatedwithmodelrenementtools.Thisreportdescribesthestylesofnetworkmodelsautomaticallygeneratedbythenetworkrenementtool.Thereforeitcanhelpdesignersunderstandthenetworkmodels.Itcanalsobeusedasareferencemaunalifdesignerswanttowritetheirownnetworkmodelsthatarevalidinputtothecommunicationrenementtool.Contents1Introduction11.1SoCDesignFlow........................................11.2SpecCLanguage........................................22AnOverviewofNetworkModel33LinkChannels54Memories65ProcessingElements85.1Two-ShellStructure.......................................85.2Memory-MappedIO......................................106CommunicationElements106.1Bridges.............................................136.2Transducers...........................................136.2.1Simplecase:AsynchronousTransducers.......................146.2.2MoreComplexCase:SynchrounousTransducers...................157Top-LevelDesignBehavior19References21iListofFigures1SoCdesignow.........................................22Networkmodeltop-levelcode..................................43Networkmodeltop-levelstructure................................44Interfacesimplementedbycdoublehandshakechannel.................55Interfacesimplementedbychandshakechannel.......................66Anexampleofmemorybehavior.................................77Two-shellPEstructure......................................88Examplecodeofanadapterchannel...............................99Examplecodeofmemory-mappedIOmodeling.........................1110Anexampleofbridgebehavior................................1211Anexampleofbufferbehavior................................1412Anexampleofrepeaterbehavior...............................1413Anexamplecodeoftransducerbehavior..........................1514Anexampleofsynchronoustransducerforsynchronouscommunication............1615Anexampleofsynchronoustransducerforasynchronouscommunication...........1716Anexampleofsynchronoustransducerforasynchronouscommunication...........1817Exampleofatop-leveldesignbehaviorcode..........................19iiSystem-On-ChipNetworkModelingStyleGuideD.Shin,J.Peng,A.Gerstlauer,R.D¨omerandD.D.Gajski.CenterforEmbeddedComputerSystemsUniversityofCalifornia,IrvineJuly31,2004AbstractTheSCEsystem-leveldesignowconsistsofaseriesofrenementstepsthatgraduallytransformanab-stractspecicationmodelintoanarchitecturemodel,anetworkmodel,acommunicationmodelandnallyadetailedimplementationmodel.Thetransformationscanbeautomatedwithmodelrenementtools.Thisreportdescribesthestylesofnetworkmodelsautomaticallygeneratedbythenetworkrenementtool.Thereforeitcanhelpdesignersunderstandthenetworkmodels.Itcanalsobeusedasareferencemaunalifdesignerswanttowritetheirownnetworkmodelsthatarevalidinputtothecommunicationrenementtool.1IntroductionSystemdesignintheSoCapproachtakesaninitialspecicationofthesystemdowntoanactualimplemen-tationthroughaseriesofinteractiveandautomatedsteps.Startingfromapurelyfunctionaldescriptionofthedesiredsystembehavior,animplementationofthedesignonaheterogeneoussystemarchitecturewithmultipleprocessingelements(PEs)connectedthroughsystembussesisproducedattheendofthedesignow.ThisreportdescribesanddenesguidelinesandrulesfordevelopingSpecCbasedsystemmodelsingeneral,andasinputtotheSoCtoolsinparticular.1.1SoCDesignFlowIntheSoCdesignow(Figure1),vedesignmodelsareusedtorepresentthedesignatdifferentabstractionlevels.Thedesignmodelsareexecutablesothattheycanbesimulatedtoverifythecorrectnessofthedesignandobtaindesignperformancemetricsateachdesignstep.ThemostabstractmodelisthespecicationmodelthatservesastheinputtoSoCtools.Specicationmodelisapurefunctionalmodelthatcapturesthefunctionalityofthedesireddesign.Itshouldnotcontainanyimplementationdetails.Thearchitecturemodelistheoutputofarchitectureexploration.Itreectstheoverallcomputationar-chitectureconsistingofprocessingelements(PEs).ThearchitecturemodelencapsulatesthecommunicationbetweenPEsthroughabstractmessage-passingchannels.Afternetworkexplorationanetworkmodelisproducedtoreectthecommunicationnetworkchosenforthedesign.Itrepresentstheallocationandselectionofnetworkstationsandthelinksbetweenthem.Whilethecommunicationisend-to-endbetweenPEsinthearchitecturemodel,itisrenedintopoint-to-pointinthenetworkmodel.1ArchitectureExplorerNetworkExplorerCommunicationSynthesizerPEDatabaseCEDatabaseBusDa