Data Sheet

USBProtocolSuiteUserManual 353
DecodingProtocol‐SpecificFieldsinTransactionsandTransfers TeledyneLeCroyCorporation
6.17 Decoding Protocol-Specific Fields in Transactions and Transfers
Whentransfersortransactionsaredisplayed,thefieldsinsetuptransactionsandin
control,interrupt,andBulktransfersdonotgetdecoded(bydefault)andareshownin
hexadecimalvalues.Theexceptionsaresetuptransactionsandcontroltransfersfor
standardUSBdevicerequests,whicharealwaysdecoded.
Toshowspecificdecodingforclass‐andvendor‐specificdevicerequestsandendpoints,
youhavetousethedecodingassociationmechanismthatisdescribedinChapter9on
decoding.Whenyouhaveperformedtheassociation,youseetheprotocol‐specificfields
oftransfersandtransactionsdecodedinthetraceview.
6.18 Switch to PTP Transactions
TheAnalyzersupportsthePictureTransferProtocol(PTP)andalsosupportsthe
Media TransferProtocol(MTP),whichisanextensionofPTP.TheAnalyzercantrackPTP
transactions,objecttransfers,andsessions.
Atransactionisastandardsequenceofphasesforinvokinganaction.InPTP,anInitiator‐
initiatedactionprovidesinputparameters,responseswithparameters,andbinarydata
exchange,andisasinglePTPTransaction.Also,asingleAsynchronous Eventsentthrough
theinterruptpipeisasinglePTPTransaction.
ThePTPTransactiontraceviewinglevelisthelowestPTPlevel.
ToviewPTPtransactions,switchtothePTPTransactiontraceviewinglevel:
 Click onthetoolbar.
OR
 SelectView>PTPGroup>PTPTransactionLevel.
OR
 SelectSetup>DisplayOptionstodisplaytheDisplayOptionswindow,checkPTP
Transaction,andthenclickOK.
6.19 Switch to PTP Object Transfers
Alogicalobjectonadevicehasaunique32‐bitidentifier(object handle).The
object handleisalsouniqueforthesession(definedbelow).Anobject transfercontains
allthetransactionsforanobject handle.InPTP,allofanobject handle’sPTP Transactions
areasinglePTP Object Transfer.
APTP Object TransfercanincludebothPTP TransactionsthatinvolveanInitiator‐initiated
action(forexample,GetObject,DeleteObject,andGetObjectInfotransactions)and
PTP TransactionsthatinvolveasingleAsynchronousEventsentthroughtheinterrupt
pipe.
ThePTP Object TransfertraceviewinglevelisthemiddlePTPlevel.
ToviewPTPobjecttransfers,switchtothePTPObjectTransfertraceviewinglevel: