Added Features, Code Rates | Texas Instruments TMS320C6457 DSP

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Figure 98. Example R Formula

	RMAX	+ 128
	if(N v 128)
			NSW + 1, R + N
	ELSE
			NSW + 2
	IFNSW + 2 {
	whileNSB R					NSW * N w (R * 48) {
	WIN_SIZE + CEIL NNSW
	NSB + CEIL			WIN_SIZE
	NSB + CEIL					RMAX
	R +	WIN_SIZE
	R +		NSB
			NSB
	IFR		NSB t WIN_SIZER ) )
	RMAX	+ RMAX * 1
	}
	NSW	+ NSW * 1
	This computation should be done by the DSP CPU. It should be noted that a 1 must be subtracted from
	the calculated R value prior to writing to TCPIC1.
	Note: The reliability length must fill the above properties to receive a correct decoding. If these
	rules are not followed, the MAP will execute, but the BER might not be optimal.
8.4	Added Features
8.4.1	Code Rates
	TCP only supports the code rates used in the 3GPP and cdma2000 standards, namely 1/2, 1/3 and 1/4.
	TCP2 introduces a more flexible design which always assumes that the code rate is 1/5. Therefore, all
	puncturing schemes derived from the rate 1/5 mother code are automatically supported. The received
	systematic and parity data is first de-punctured to rate 1/5, then formatted according to the TCP
	specifications (see Section 4.1), and finally sent to the TCP.

SPRUGK1–March 2009

TMS320C6457 Turbo-Decoder Coprocessor 2

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Texas Instruments TMS320C6457 DSP manual Added Features, Code Rates

Contents

Users Guide Submit Documentation Feedback Contents Added Features Programming EDMA3 Resources List of Figures Destination of Endianness Manager Outorder = List of Tables Trademarks About This ManualNotational Conventions Related Documentation From Texas Instruments TMS320C6457 Turbo-Decoder Coprocessor Features Introduction GPP and IS2000 Turbo-Encoder Block Diagram Overview GPP and IS2000 Turbo-Decoder Block Diagram TCP2 Mode Standalone SA Mode Systematic and Parity Data Input Data Format SP9 SP8 SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 Rsvd SP9 SP8 SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0SP9 SP8 SP7 SP6 SP5 SP4 SP3 SP0 SP4 SP3 SP2 SP1 SP0 SP9 SP8 SP7 SP6 SP5 EN = 0 Big-Endian Mode Rate = 1/4 Interleaver Data Output Decision Data FormatStopping Criteria Interleaver Indexes Stopping Test Unit SNR Threshold TerminationCRC Termination Minimum Iterations Shared-Processing SP ModeParameter Termination Maximum Iterations Shared-Processing SP Mode Block Diagram Subframe Equations Submit Documentation Feedback TCP2 Shared Processing Block Diagram EN = 1 Little-Endian Mode Rate = 1/3 Output Data Format Priori DataRsvd AP4 AP3 AP2 AP1 AP0 AP9 AP8 AP7 AP6 AP5 Name RegistersTCP2 Registers TCP2 RAMs Registers Description Peripheral Identification Register PIDPeripheral Identification Register PID Field Descriptions Bit Field Bit Field Value Description TCP2 Input Configuration Register 0 TCPIC0 Maxit TCP2 Input Configuration Register 1 TCPIC1TCP2 Input Configuration Register 2 TCPIC2 SNR TCP2 Input Configuration Register 3 TCPIC3 TCP2 Input Configuration Register 4 TCPIC4 CrciterpassCrclen Crcpoly TCP2 Input Configuration Register 5 TCPIC5Tail Symbols CRC Examples TAIL1 TCP2 Input Configuration Register 6 TCPIC6 TAIL2 10 TCP2 Input Configuration Register 7 TCPIC7 TAIL3 11 TCP2 Input Configuration Register 8 TCPIC8 TAIL4 12 TCP2 Input Configuration Register 9 TCPIC9 13 TCP2 Input Configuration Register 10 TCPIC10 14 TCP2 Input Configuration Register 11 TCPIC11TAIL5 TCP2 Input Configuration Register 11 TCPIC11 EXTSCALE47 15 TCP2 Input Configuration Register 12 TCPIC1216 TCP2 Input Configuration Register 13 TCPIC13 EXTSCALE03 EXTSCALE811 17 TCP2 Input Configuration Register 14 TCPIC14 Iteration Number 18 TCP2 Input Configuration Register 15 TCPIC15Extrinsic Scale Registers EXTSCALE1215 TCP2 Output Parameter Register 1 TCPOUT1 Field Descriptions 19 TCP2 Output Parameter Register 0 TCPOUT020 TCP2 Output Parameter Register 1 TCPOUT1 TCP2 Output Parameter Register 0 TCPOUT0 Field Descriptions TCP2 Execution Register Tcpexe Field Descriptions 21 TCP2 Output Parameter Register 2 TCPOUT222 TCP2 Execution Register Tcpexe TCP2 Output Parameter Register 2 TCPOUT2 Field Descriptions Endianextr 23 TCP2 Endian Register TcpendTCP2 Endian Register Tcpend Field Descriptions Endian Extr Intr TCP2 Error Register Tcperr Field Descriptions 24 TCP2 Error Register Tcperr Subframe length 25 TCP2 Status Register Tcpstat TCP2 Status Register Tcpstat Field DescriptionsTcpstate Waiting for RAM extrinsic memory 0 to be read Soft Free 26 TCP2 Emulation Register TcpemuTCP2 Emulation Register Tcpemu Field Descriptions Soft = Data Memory for Systematic Endianness 6362 6156 5550 4944 4338 3732 3130 2924 2318 1712 116 Data Memory EN = 0 Big-Endian Mode Rate = 1/4 Hard Decision Data EN = 0 Big-Endian Mode Rate = 3/4 HD1 HD0 Hard Decisions in DSP MemoryTcpendian Register for Endianness Manager Data Data Native Format DSP Memory Format Tcpendian Programming RegisterEndianintr = Interleaver Indexes in DSP Memory INTER3 INTER2 INTER1 INTER0 INTER0 INTER1 INTER2 INTER3 Extrinsic Data Endianextr =Extrinsic in DSP Memory Endianextr = Data Source Kernel Endianextr = Architecture EXT7 EXT6 EXT5 EXT4 EXT3 EXT2 EXT1 EXT0EXT3 EXT2 EXT1 EXT0 EXT7 EXT6 EXT5 EXT4 Sub-block and Sliding Window Segmentation MAP Unit Block Diagram Examples for NUMBLOCK, NUMSUBBLOCK, NUMSW, and Winrel Subframe Segmentation SP mode only Reliability and Prolog Length Calculation Code Rates Added Features Log Equation Valid Re-Encode Symbols Used for ComparisonProgramming Input Sign 1 TCP2 Dedicated EDMA3 Resources EDMA3 Parameters in Standalone SA ModeEDMA3 Parameters in Shared Processing SP Mode EDMA3 Resources Systematics and Parities Transfer Programming Standalone SA ModeInput Configuration Parameters Transfer EDMA3 Programming Interleaver Indexes Transfer Hard-Decisions Transfer Output Parameters Transfer Input Configurations Parameters Programming Outf TCPIC0 Programming Shared-Processing SP ModeOpmod TCPIC0 Inter TCPIC0 Input Configuration Parameters Transfer Priori Transfer Extrinsics Transfer Output Parameters Events GenerationInter TCPIC0 Inter = Outf Error Status ERR Debug Mode Pause After Each MapErrors and Status Errors Unexpected Prolog Length P Unexpected Signal to Noise Ratio SNRUnexpected Memory Access ACC Unexpected Frame Length F Status 13.2.15 TCP2 CRC Status Crcpass 13.2.12 TCP2 Active State Status Activestate13.2.13 TCP2 Active Iteration Status Activeiter 13.2.14 TCP2 SNR Status snrexceed Products Applications DSPRfid