Datasheet

SPIRegister(PCM2705/7)
PCM2704, ,PCM2705
PCM2706,PCM2707
www.ti.com .......................................................................................................................................................SLES081F–JUNE2003–REVISEDJANUARY2009
B15B14B13B12B11B10B9B8B7B6B5B4B3B2B1B0
0000ST0ADDR0D0D1D2D3D4D5D6D7
D[7:0]Functionofthelower8bitsdependsonthevalueoftheST(B11)bit.
ST=0(HIDstatuswrite)
D7ReportsMUTEHIDstatustothehost(activehigh)
D6Reportsvolume-upHIDstatustothehost(activehigh)
D5Reportsvolume-downHIDstatustothehost(activehigh)
D4Reportsnext-trackHIDstatustothehost(activehigh)
D3Reportsprevious-trackHIDstatustothehost(activehigh)
D2ReportsstopHIDstatustothehost(activehigh)
D1Reportsplay/pauseHIDstatustothehost(activehigh)
D0Reportsextendedcommandstatustothehost(activehigh)
ST=1(ROMdatawrite)
D[7:0]InternaldescriptorROMdata,D0:LSB,D7:MSB
Thecontentofpowerattributeandmaxpowermustbeconsistentwiththeactualapplicationcircuit
configuration(PSELsettingandactualpowerusagefromVBUSofUSBconnector);otherwise,itmaycause
improperorunexpectedPCM2705/7operation.
ADDRStartswriteoperationforinternaldescriptorreprogramming(activehigh)
ThisbitresetsdescriptorROMaddresscounterandindicatesfollowingwordsshouldbeROMdata(described
intheExternalROMExamplesection).456bitsofROMdatamustbecontinuouslyfollowedafterthisbithas
beenasserted.ThedatabitsmustbesentfromLSB(D0)toMSB(D7).
TosetADDRhigh,STmustbesetlow.Notethatthelower8bitsarestillactiveasanHIDstatuswritewhen
STissetlow.
STDeterminesthefunctionofthelower8-bitdataasfollows:
0:HIDstatuswrite
1:DescriptorROMdatawrite
Table6.FunctionalityofSTandADDRBitCombinations
STADDRFUNCTION
00HIDstatuswrite
01HIDstatuswriteanddescriptorROMaddressreset
10DescriptorROMdatawrite
11Reserved
Copyright©2003–2009,TexasInstrumentsIncorporatedSubmitDocumentationFeedback25
ProductFolderLink(s):PCM2704PCM2705PCM2706PCM2707
PCM2704 and PCM2705
Not Recommended For New Designs