USB 2.0

UniversalSerialBusSpecificationCompaqHewlett-PackardIntelLucentMicrosoftNECPhilipsRevision2.0April27,2000UniversalSerialBusSpecificationRevision2.0iiScopeofthisRevisionThe2.0revisionofthespecificationisintendedforproductdesign.Everyattempthasbeenmadetoensureaconsistentandimplementablespecification.Implementationsshouldensurecompliancewiththisrevision.RevisionHistoryRevisionIssueDateComments0.7November11,1994Supersedes0.6e.0.8December30,1994RevisionstoChapters3-8,10,and11.Addedappendixes.0.9April13,1995Revisionstoallthechapters.0.99August25,1995Revisionstoallthechapters.1.0FDRNovember13,1995RevisionstoChapters1,2,5-11.1.0January15,1996EditstoChapters5,6,7,8,9,10,and11forconsistency.1.1September23,1998Updatestoallchapterstofixproblemsidentified.2.0(draft0.79)October5,1999Revisionstochapters5,7,8,9,11toaddhighspeed.2.0(draft0.9)December21,1999Revisionstoallchapterstoaddhighspeed.2.0April27,2000Revisionsforhigh-speedmode.UniversalSerialBusSpecificationCopyright©2000,CompaqComputerCorporation,Hewlett-PackardCompany,IntelCorporation,LucentTechnologiesInc,MicrosoftCorporation,NECCorporation,KoninklijkePhilipsElectronicsN.V.Allrightsreserved.INTELLECTUALPROPERTYDISCLAIMERTHISSPECIFICATIONISPROVIDEDTOYOU“ASIS”WITHNOWARRANTIESWHATSOEVER,INCLUDINGANYWARRANTYOFMERCHANTABILITY,NON-INFRINGEMENT,ORFITNESSFORANYPARTICULARPURPOSE.THEAUTHORSOFTHISSPECIFICATIONDISCLAIMALLLIABILITY,INCLUDINGLIABILITYFORINFRINGEMENTOFANYPROPRIETARYRIGHTS,RELATINGTOUSEORIMPLEMENTATIONOFINFORMATIONINTHISSPECIFICATION.THEPROVISIONOFTHISSPECIFICATIONTOYOUDOESNOTPROVIDEYOUWITHANYLICENSE,EXPRESSORIMPLIED,BYESTOPPELOROTHERWISE,TOANYINTELLECTUALPROPERTYRIGHTS.Allproductnamesaretrademarks,registeredtrademarks,orservicemarksofth[e-mail]n,refertotheUSBImplementersForumwebpageat(Chair/Editor)KenStufflebeamCompaqComputerCorporationDavidWootenCompaqComputerCorporationMattNiebergerHewlett-PackardCompanyJohnHowardIntelCorporationVenkatIyerIntelCorporationSteveMcGowanIntelCorporationGeertKnapenRoyalPhilipsElectronicsZongLiangWuRoyalPhilipsElectronicsJimCleeLucentTechnologiesIncJimGuziakLucentTechnologiesIncDaveThompsonLucentTechnologiesIncJohnFullerMicrosoftCorporationNathanShermanMicrosoftCorporationMarkWilliamsMicrosoftCorporationNobuoFuruyaNECCorporationToshimiSakuraiNECCorporationMotoSatoNECCorporationKatsuyaSuzukiNECCorporationElectricalWorkingGroupJonLuekerIntelCorporation(Chair/Editor)DavidWootenCompaqComputerCorporationMattNiebergerHewlett-PackardCompanyLarryTaugherHewlett-PackardCompanyVenkatIyerIntelCorporationSteveMcGowanIntelCorporationMikePennellIntelCorporationToddWestIntelCorporationGerritdenBestenRoyalPhilipsElectronicsMarqKoleRoyalPhilipsElectronicsZongLiangWuRoyalPhilipsElectronicsJimCleeLucentTechnologiesIncJimGuziakLucentTechnologiesIncParParikhLucentTechnologiesIncDaveThompsonLucentTechnologiesIncEdGiaimoMicrosoftCorporationMarkWilliamsMicrosoftCorporationToshihikoOhtaniNECCorporationKugaoOuchiNECCorporationKatsuyaSuzukiNECCorporationToshioTasakiNECCorporationUniversalSerialBusSpecificationRevision2.0ivUniversalSerialBusSpecificationRevision2.0vContentsCHAPTER1INTRODUCTION1.1Motivation..............................................................................................................................................11.2ObjectiveoftheSpecification...............................................................................................................11.3ScopeoftheDocument..........................................................................................................................21.4USBProductCompliance.....................................................................................................................21.5DocumentOrganization........................................................................................................................2CHAPTER2TERMSANDABBREVIATIONSCHAPTER3BACKGROUND3.1GoalsfortheUniversalSerialBus.....................................................................................................113.2TaxonomyofApplicationSpace.........................................................................................................123.3FeatureList..........................................................................................................................................13CHAPTER4ARCHITECTURALOVERVIEW4.1USBSystemDescription.....................................................................................................................154.1.1BusTopology...........................