Datasheet

DeviceConfiguration
Analog Out
Default
Endpoint
Endpoint #2
(IF #1)
Audio Streaming
Interface
Endpoint #0
Endpoint #5
(IF #2)
HID Interface
IT
TID1
FU
UID3
OT
TID2
Standard Audio Control Interface (IF #0)
PCM2704/5/6/7
M0024-01
Interface#0(Default/ControlInterface)
PCM2704, ,PCM2705
PCM2706,PCM2707
www.ti.com .......................................................................................................................................................SLES081F–JUNE2003–REVISEDJANUARY2009
Figure21illustratestheUSBaudiofunctiontopology.ThePCM2704/5/6/7hasthreeinterfaces.Eachinterfaceis
enabledbysomealternativesettings.
Figure21.USBAudioFunctionTopology
Interface#0isthecontrolinterface.Setting#0istheonlypossiblesettingforinterface#0.Setting#0describes
thestandardaudiocontrolinterface.Audiocontrolinterfaceconsistsofaterminal.ThePCM2704/5/6/7hasthree
terminals:
•Inputterminal(IT#1)forisochronous-outstream
•Outputterminal(OT#2)foraudioanalogoutput
•Featureunit(FU#3)forDACdigitalattenuator
Inputterminal#1isdefinedasaUSBstream(terminaltype0x0101).Inputterminal#1canaccepttwo-channel
audiostreamsconstructedofleftandrightchannels.Outputterminal#2isdefinedasaspeaker(terminaltype
0x0301).Featureunit#3supportsthefollowingsoundcontrolfeatures:
•Volumecontrol
•Mutecontrol
Thebuilt-indigitalvolumecontrollercanbemanipulatedbyanaudio-class-specificrequestfrom0dBto–64dB
instepsof1dB.Changesaremadebyincrementingordecrementingonestep(1dB)forevery1/f
S
timeinterval,
untilthevolumelevelreachestherequestedvalue.Eachchannelcanbesettoaseparatevalue.Themaster
volumecontrolisnotsupported.Arequesttothemastervolumeisstalledandignored.Thebuilt-indigitalmute
controllercanbemanipulatedbyanaudio-class-specificrequest.Amastermutecontrolrequestisacceptable.A
mutecontrolrequesttoanindividualchannelisstalledandignored.Thedigitalvolumecontroldoesnotaffect
theS/PDIFandI
2
Soutputs(PCM2706/7).
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ProductFolderLink(s):PCM2704PCM2705PCM2706PCM2707
PCM2704 and PCM2705
Not Recommended For New Designs