Data Sheet

TeledyneLeCroyCorporation TraceViewFeatures
312 USBProtocolSuiteUserManual
6.1.2 USB 3.1 Packets
USB3.1hasthefollowingpackettypes:
 LinkTrainingSequences
 TSEQ
 TS1
 TS2
 LFPSPackets
 ElectricalIdles
 LinkCommands
 SKP
 HeaderPackets
 PayloadPackets
 Datapackets
 LogicalIdlePackets
 BRST
 BERC
 BCNT
 TerminationPackets(TimestampedwhenterminationisdetectedbyAnalyzer)
 CP
 VBusChange(On/Off)
 SYNC
 SDS
Inaddition,therearetwopackettypesprovidedwhichshowsymboltrafficwhichcannot
beassembledintoaknownUSB3.1packettypes:
 IPS(Inter‐PacketSymbols)‐ThesecanoccurwhenthelinkisinU0butthereare
symbolsseenwhichdonotformapacket.ThiscanbecausedbyabadUSBcable
orsomeothersignalintegrityissue.Sincethesecannotbedecoded,thisiscon‐
sideredtobean"Error".
 USS(UnidentifiedSymbolSequence)‐Theseoftenoccurduringthetransition
intoandoutofU0.Sincetheyarefoundduringthistransitionperiodandnor‐
mallydonotinterferewiththelinkcominguporgoingdown,theyareclassified
asa"Warning".Theycangenerallybeignored.
6.1.3 Packet Direction
ThePacketDirectionfielddisplaysthedirectionthepacketorsignalwastravelingonthe
bus:DownstreamfromaHost orUpstreamfromaDevice .
Inmostcases,directioncanbedeterminedunambiguously.However,somesignalsand
situations,includingprotocolerrors,cannotbedeterminedwithhighconfidence,since
eitherHostorDevicemightberesponsibleforthem.Suchcasesaremarkedas
Question Marks inthetrace.