Data Sheet

USBProtocolSuiteUserManual 447
GeneralOptions TeledyneLeCroyCorporation
9.3 General Options
CommandsaretransferredonUSBusingspecialcontroltransferscalledUSBDevice
Requests.TheAnalyzercandecodeDeviceRequestsastheyaredefinedintheUSB
specificationsandvariousDeviceClassandVendorspecifications.
EachUSBDeviceRequestissentusingaControlTransfer.EachControlTransferstartswith
aSETUPtransaction.
9.3.1 Decoding USB Device Requests
TodecodeaUSBDeviceRequest:
1. Right‐clicktheControlTransferfieldortheSETUPfieldoftheUSB Device Requestto
displaytheUSB Device Requestmenu:
Figure 9.16: USB Device Request Dialog
Note:Themenusshowninthissectionarecontext‐sensitive.Youmayseeslightlydifferentmenus.
2. Torefreshdecoding,clickRefreshDecodingforthisTraceFile.Usethisoptionto
reanalyzealltransactions.
3. Tousethepreviousdecoding,clickLoadmostrecentdecodingmapping.
Thisoptionloadsthemostrecentmappingofendpoints/requeststodecodingtypes
thatwasdoneonaprevioustrace.Iftheendpointsofthenewtracearethesameas
thelastonemapped,themappingsareappliedtothecurrenttrace.Thissavesthe
userfromhavingtoconstantlyapplythemappingtoanewtraceeverytimethe
applicationisrestartedandanewtracecreated.
TheabilitytoretainthemappingfromtracetotraceDURINGanapplicationsession
alreadyexists:theKeepAcrossRecordingsbuttonintheendpointmapdialog.This
newfeaturesimplifiestheprocesswhentheapplicationhasbeenre‐started.
Note:Youcanalsochangetheformat,color,andhiddenstatusoffields,usingthesamemethodsasin
DisplayOptions.(Chapter8,“DisplayOptions,”onpage 409)