PCIASPM

ActiveStatePowerManagementinWindowsVistaApril13,2006AbstractActiveStatePowerManagement(ASPM)allowspowertoindividualserialLinksinaPCIExpressfabrictobeincrementallyreducedasaLinkbecomeslessactive.Microsoft®WindowsVista™supportsASPMenhancementstothePCIbusdriverandtheWindowskernelpowermanager.ThispaperprovidesanoverviewofASPMsupportinWindowsVistaforhardwarevendorsandsystemmanufacturers.ThecurrentversionofthispaperismaintainedontheWebat:错误!使用“开始”选项卡将Title应用于要在此处显示的文字。-2April13,2006©2006MicrosoftCorporation.Allrightsreserved.DisclaimerThisisapreliminarydocumentandmaybechangedsubstantiallypriortofinalcommercialreleaseofthesoftwaredescribedherein.TheinformationcontainedinthisdocumentrepresentsthecurrentviewofMicrosoftCorporationontheissuesdiscussedasofthedateofpublication.BecauseMicrosoftmustrespondtochangingmarketconditions,itshouldnotbeinterpretedtobeacommitmentonthepartofMicrosoft,andMicrosoftcannotguaranteetheaccuracyofanyinformationpresentedafterthedateofpublication.ThisWhitePaperisforinformationalpurposesonly.MICROSOFTMAKESNOWARRANTIES,EXPRESS,IMPLIEDORSTATUTORY,ASTOTHEINFORMATIONINTHISDOCUMENT.Complyingwithallapplicablecopyrightlawsistheresponsibilityoftheuser.Withoutlimitingtherightsundercopyright,nopartofthisdocumentmaybereproduced,storedinorintroducedintoaretrievalsystem,ortransmittedinanyformorbyanymeans(electronic,mechanical,photocopying,recording,orotherwise),orforanypurpose,withouttheexpresswrittenpermissionofMicrosoftCorporation.Microsoftmayhavepatents,patentapplications,trademarks,copyrights,orotherintellectualpropertyrightscoveringsubjectmatterinthisdocument.ExceptasexpresslyprovidedinanywrittenlicenseagreementfromMicrosoft,thefurnishingofthisdocumentdoesnotgiveyouanylicensetothesepatents,trademarks,copyrights,orotherintellectualproperty.Unlessotherwisenoted,theexamplecompanies,organizations,products,domainnames,e-mailaddresses,logos,people,placesandeventsdepictedhereinarefictitious,andnoassociationwithanyrealcompany,organization,product,domainname,emailaddress,logo,person,placeoreventisintendedorshouldbeinferred.©2006MicrosoftCorporation.Allrightsreserved.Microsoft,Windows,andWindowsVistaareeitherregisteredtrademarksortrademarksofMicrosoftCorporationintheUnitedStatesand/orothercountries.Thenamesofactualcompaniesandproductsmentionedhereinmaybethetrademarksoftheirrespectiveowners.错误!使用“开始”选项卡将Title应用于要在此处显示的文字。-3April13,2006©2006MicrosoftCorporation.Allrightsreserved.IntroductionActiveStatePowerManagement(ASPM)allowsindividualserialLinksinaPCIExpressfabrictohavepowerincrementallyreducedasaLinkbecomeslessactive.ASPMisdefinedinPCIExpressBaseSpecification.ASPMhasbeenincorporatedintoPCIExpressasamethodtobettermanagesystempowerconsumption.DuetotheserialtechnologythatisusedinPCIExpress,ASPMisuniquetoPCIExpressandisnotpresentinconventionalPCIorPCI-X.Microsoft®WindowsVista™supportsASPMthroughenhancementstothePCIbusdriverandMicrosoftWindows®powermanager.WindowsVistaenablesordisablesASPMforaLink,basedontheoverallsystempowerpolicy,thehardwarecapabilitiesoftheLink,andthelatencyoftheLink.HardwareperformstheactualpowermanagementoperationsoftransitioningLinksbetweenLinkpowerstatesandresynchronizingLinks.TheconfigurationofthePCIExpressimplementationonasystemaffectstheamountofpowersavingsthatcanactuallybeachieved.ThispaperdescribeshowWindowsVistaconfiguresthePCIExpressfabrictoenablethemaximumpowersavings.HardwarevendorsandsystemmanufacturerscanusetheinformationinthispapertodesigntheirsystemstotakeadvantageofASPMsupportinWindowsVista.TheEffectofBusArchitectureonPowerConsumptionThePCIandPCI-Xinterfacesarebothbasedonparallelbusarchitectures.Whennodataissent,thereisnoa