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9.3.1.4ExtrinsicsTransfer
9.3.2InputConfigurationsParametersProgramming
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Programming
1.TheEDMA3inputconfigurationparameterstransferparametersofthenextuser-channelMAP,ifthere
isonereadytobedecoded.
2.DummyEDMA3transferparameters,iftherearenomoreuserchannelsLOG-MAPreadytobe
decoded.
ThisEDMA3transfertotheextrinsicsbufferisaTCPREVTframe-synchronizedtransfer.Theparameters
shouldbesetas:
•OPTIONS:
–ITCCEN=0(Intermediatetransfercompletechainingisdisabled)
–TCCEN=0(Transfercompletechainingisdisabled)
–ITCINTEN=0(Intermediatetransfercompleteinterruptisdisabled)
–TCINTEN=1(Transfercompleteinterruptisdisabled)
–TCC=1to63(TransferCompleteCode)
–TCCMODE=0(NormalCompletion)
–FWID=Don'tcare
–STAT=0(Entryisupdatedasnormal)
–SYNCDIM=0(A-Sync.EacheventtriggersthetransferofACNTelements.)
–DAM=0(Dstaddressingwithinanarrayincrements.DstisnotaFIFO.)
–SAM=0(Srcaddressingwithinanarrayincrements.SourceisnotaFIFO.)
•IftheOPMODE==FIRST_SUB_FRAME
SOURCEADDRESS:TCPEXT(50030000h)
•IftheOPMODE==MIDDLE_SUB_FRAMEorLAST_SUB_FRAME
SOURCEADDRESS:TCPEXT(50030000h+prolog_length)
•ACNT=8*ceil((frame_length)/8)⇒(Noofbytesinanarray)
•BCNT=1(NoofarraysoflengthACNT)
•DESTINATIONADDRESS:Userextrinsicsstartaddress(mustbedouble-wordaligned)
•SRCBIDX=0(Source2ndDimensionIndex)
•DSTBIDX=0(Destination2ndDimensionIndex)
•SRCCIDX=0(Source3rdDimensionIndex)
•DSTCIDX=0(Destination3rdDimensionIndex)
•CCNT=1(Noofframesinablock)
•BCNTRLD:Don'tcare
•LINKADDRESS:Seecases1and2below
Uponcompletion,thisEDMA3transferislinkedtooneofthefollowing:
1.TheEDMA3extrinsicstransferparametersofthenextuser-channel,ifthereisonereadytobe
decoded.
2.NullEDMA3transferparameters(allwithallzeros),iftherearenomoreuser-channelsreadytobe
decoded.
Theframelength(FLbitsinTCPIC0)shouldbesettothetotalshared-processingframelength(priorto
turbo-encodingandnotincludinganytailinformation).
Themaximumnumberofiterations(MAXITbitsinTCPIC2)shouldbeselectedasafunctionoftheoverall
systemperformance.Avalueof0setsthemaximumnumberofiterationstoitsmaximum(32).
•TheSNRthresholdratio(SNRbitsinTCPIC2)shouldbedisabled.
•TheCRCbitsin(TCPIC4)shouldbedisabled.
•Theprologreductionshouldbedisabled.
•Theextrinsicscalingshouldbedisabled.
SPRUGK1–March2009TMS320C6457Turbo-DecoderCoprocessor273
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