您好,欢迎访问三七文档
当前位置:首页 > 机械/制造/汽车 > 机械/模具设计 > errata-092800-1207001
1Erratafor“USBRevision2.0April27,2000”asof12/7/2000Checkthe:Thetablesinchapter5showinghigh-speedtransactionoverheadshavetypographicalerrorswheretheinterpacketgapandminimumbusturnaroundtimevalueswerereversed.Nofunctionalimpact.Change:p.43,table5-3&p.45,table5-5andp.51,table5-8:change“…8bitinterpacketgap,88bitminbus…”to“…88bitinterpacketgap,8bitminbus…”.Table5-3.High-speedControlTransferLimitsProtocolOverhead(173bytes)(Basedon480Mb/sand88bitinterpacketgap,88bitminbusturnaround,32bitsync,8bitEOP:(9x4SYNCbytes,9PIDbytes,6EP/ADDR+CRC,6CRC16,8Setupdata,9x(1+11)byteinterpacketdelay(EOP,etc.))DataPayloadMaxBandwidth(bytes/second)MicroframeBandwidthperTransferMaxTransfersBytesRemainingBytes/MicroframeUsefulData13440002%43184326720002%4215084413440002%4266168826240002%41793281649920003%391296243292160003%36120115264158720003%311531984Max6000000075002Table5-8.High-speedInterruptTransactionLimitsProtocolOverhead(Basedon480Mb/sand88bitinterpacketgap,88bitminbusturnaround,32bitsync,8bitEOP:(3x4SYNCbytes,3PIDbytes,2EP/ADDR+CRCbytes,2CRC16anda3x(1+11)byteinterpacketdelay(EOP,etc.))DataPayloadMaxBandwidth(bytes/second)MicroframeBandwidthperTransferMaxTransfersBytesRemainingBytes/MicroframeUsefulData110640001%13352133220960001%13133262440640001%1277508876160001%119395216134400001%10545168032220160001%8618275264322560002%6334032128409600002%401805120256491520004%24366144512532480008%13129665610244915200014%61026614420484915200028%31191614430724915200042%212466144Max6000000075003Table5-5.High-speedIsochronousTransactionLimitsProtocolOverhead(Basedon480Mb/sand88bitinterpacketgap,88bitminbusturnaround,32bitsync,8bitEOP:(2x4SYNCbytes,2PIDbytes,2EP/ADDR+addr+CRC5,2CRC16,anda2x(1+11))byteinterpacketdelay(EOP,etc.))DataPayloadMaxBandwidth(bytes/second)MicroframeBandwidthperTransferMaxTransfersBytesRemainingBytes/MicroFrameUsefulData115360001%19212192229920001%18720374456960001%178247128104320001%1632130416176640001%13848220832273920001%10710342464373760001%73544672128460800002%45305760256512000004%251506400512532480007%13350665610245734400014%766716820484915200028%31242614430724915200041%212806144Max6000000075004Chapter7IssuewithTest_SE0_NAKBehavior:Background:WhileintestmodeTest_SE0_NAK,upstreamfacingports“mustrespondtoanyINtokenpacketwithaNAKhandshake(onlyifthepacketCRCisdeterminedtobecorrect)withinthenormaldeviceresponsetime.”Thequestionhasbeenraisedastothemeaningof“anyINtoken”andwhetheradevicemustNAKevenifthepacketisnotdirectedtothedeviceordirectedtoanyendpointonthatdevice.Ifitmust,adeviceplacedinthistestmodewillNAKevenwhenanINtokenisdirectedtoanotherdevices,suchasamouseorkeyboard,resultinginpossibleproblemsforotherdevicesconnectedtothebusduringcompliancetesting.Atthispoint,thereareprobablyimplementationsthatinterpretthespecbothways,sothiserratumexpandsthespectoalloweitherinterpretation.Thiswillhavetobedealtwithincompliancetesting.Therewillbenoimpactonnon-test-modeoperation.Change:p.169,section7.1.20,1stbullet,3rdsentence:Changecompletesentenceto:“Inaddition,whileinthismode,upstreamfacingports(andonlyupstreamfacingports)mustrespondtoanyINtokenpacketdirectedtothedevice(withanendpointnumbersupportedbythedevice),andoptionallytoanyINtokenpacketwhichisnotdirectedtothedeviceoroptionallywithanyendpointnumber,withaNAKhandshake(onlyifthepacketCRCisdeterminedtobecorrect)withinthenormaldeviceresponsetime.Note:Thismeansthatthehostshouldsendtestpacketstoadeviceundertestwiththedevice’scurrentaddressandendpointnumberzerotoensurethatthedevicewillrespond.”7.1.20TestModeSupportTofacilitatecompliancetesting,hostcontrollers,hubs,andhigh-speedcapablefunctionsmustsupportthefollowingtestmodes:•TestmodeTest_SE0_NAK:Uponcommand,aport’stransceivermustenterthehigh-speedreceivemodeandremaininthatmodeuntiltheexitactionistaken.Thisenablesthetestingofoutputimpedance,lowleveloutputvoltage,andloadingcharacteristics.Inaddition,whileinthismode,upstreamfacingports(andonlyupstreamfacingports)mustrespondtoanyINtokenpacketwithaNAKhandshake(onlyifthepacketCRCisdeterminedtobecorrect)withinthenormalalloweddeviceresponsetime.Inaddition,whileinthismode,upstreamfacingports(andonlyupstreamfacingports)mustrespondtoanyINtokenpacketdirectedtothedevice(withanendpointnumbersupportedbythedevice),andoptionallytoanyINtokenpacketwhichisnotdirectedtothedeviceoroptionallywithanyendpointnumber,withaNAKhandshake(onlyifthepacketCRCisdeterminedtobecorrect)withinthenormaldeviceresponsetime.Note:Thismeansthatthehostshouldsendtestpacketstoadeviceundertestwiththedevice’scurrentaddressandendpointnumberzerotoensurethatthedevicewillrespond.Thisenablestestingofthedevicesquelchlevelcircuitryand,additionally,providesageneralpurposestimulus/responsetestforbasicfunctionaltesting.5IssuewithTest_Force_EnableBehavior:Background:Thequestionhasbeenraisedastothemeaningofthelanguagethatsays“…thedisconnectbitcanbepolledwhilevaryingtheloadingontheport,allowingthedisconnectdetectionthresholdvoltagetobemeasur
本文标题:errata-092800-1207001
链接地址:https://www.777doc.com/doc-11292963 .html