9.1EDMA3Resources
9.1.1TCP2DedicatedEDMA3Resources
9.1.2SpecialTCP2EDMA3ProgrammingConsiderations
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Programming
NotethatseveraluserchannelscanbeprogrammedpriortostartingtheTCP2.
Table42.EDMA3ParametersinStandalone(SA)Mode
Direction
Transmit(DSP→TCP)
Receive(TCP→DSP)DataUsageRequired/Optional
TransmitInputconfigurationSendtheinputconfigurationRequired
parametersparameters
TransmitSystematicsandparitiesSendthesystematicsandparitiesRequired
TransmitInterleaverindexesSendtheinterleavertableOptionalINTERbit
ReceiveHarddecisionsReadtheharddecisionsRequired
ReceiveOutputparametersReadtheoutputparametersOptionalOUTFbit
Table43.EDMA3ParametersinSharedProcessing(SP)Mode
Direction
Transmit(DSP→TCP)
Receive(TCP→DSP)DataUsageRequired/Optional
TransmitInputconfigurationSendtheinputconfigurationRequired
parametersparameters
TransmitSystematicsandparitiesSendthesystematicsandparitiesRequired
TransmitApriorisSendtheapriorisRequiredexceptforfirst
iterationMAP1
ReceiveExtrinsicsReadtheextrinsicsRequired
Withintheavailable64EDMA3channelseventsources,twoareassignedtotheTCP:event30andevent
31.
•Event30isassociatedtotheTCP2receiveevent(TCPREVT)andisusedasthesynchronization
eventfortheEDMA3transferfromtheTCP2totheDSP(receive).
•Event31isassociatedtotheTCP2transmitevent(TCPXEVT)andisusedasthesynchronization
eventfortheEDMA3transferfromtheDSPtotheTCP2(transmit).
TheEDMA3parametersconsistsofeightwordsasshowninFigure99.InthecontextoftheTCP2,all
EDMA3transfersshouldfollowACNT*BCNTnumberofbytesinA_SyncModeandACNT*BCNT*
CCNTnumberofbytesinAB_SyncMode.Thenumberofbytesshouldbeamultipleof8.Formore
information,seetheTMS320C6457DSPEnhancedDirectMemoryAccess(EDMA3)ControllerReference
Guide(SPRUGK6).
Figure99.EDMA3ParametersStructure
310
EDMA3ChannelOptionsParameter(OPT)
EDMA3ChannelSourceAddress(SRC)
NumberofarraysoflengthACNT(BCNT)Numberofbytesinarray(ACNT)
EDMA3ChannelDestinationAddress(DST)
Destination2ndDimensionIndex(DSTBIDX)Source2ndDimensionIndex(SRCBIDX)
BCNTRLDLINK
Destination3rdDimensionIndex(DSTCIDX)Source3rdDimensionIndex(SRCCIDX)
ReservedNumberofframesinblock(CCNT)
SPRUGK1–March2009TMS320C6457Turbo-DecoderCoprocessor265
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