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8.17 Enhanced Turbo Decoder Coprocessor (TCP2)
8.17.1 TCP2 Device-Specific Information
TMS320TCI6482
Communications Infrastructure Digital Signal Processor
SPRS246F–APRIL 2005–REVISED MAY 2007
Table 8-96. VCP2 Registers (continued)
EDMA BUS
CONFIGURATION BUS
HEX ADDRESS RANGE
02B8 0064 - 02B9 FFFF
-
-
-
-
-
ACRONYM
REGISTER NAME
HEX ADDRESS RANGE
N/A
5800 1000
5800 2000
5800 3000
5800 6000
5800 F000
-
Reserved
Branch Metrics
State Metric
Traceback Hard Decision
Traceback Soft Decision
Decoded Bits
BM
SM
TBHD
TBSD
IO
The TCI6482 device has a high-performance embedded coprocessor [Turbo-Decoder Coprocessor
(TCP2) that significantly speeds up channel-decoding operations on-chip. With the CPU operating at 1
GHz, the TCP2 can decode up to forty 384-Kbps or eight 2-Mbps turbo-encoded channels (assuming 8
iterations). The TCP2 implements the max*log-map algorithm and is designed to support all polynomials
and rates required by Third-Generation Partnership Projects (3GPP and 3GPP2), with fully programmable
frame length and turbo interleaver. Decoding parameters such as the number of iterations and stopping
criteria are also programmable. Communications between the TCP2 and the CPU are carried out through
the EDMA3 controller.
The TCP2 supports:
Parallel concatenated convolutional turbo decoding using the MAP algorithm
All turbo code rates greater than or equal to 1/5
3GPP and CDMA2000 turbo encoder trellis
3GPP and CDMA2000 block sizes in standalone mode
Larger block sizes in shared processing mode
Both max log MAP and log MAP decoding
Sliding windows algorithm with variable reliability and prolog lengths
The prolog reduction algorithm
Execution of a minimum and maximum number of iterations
The SNR stopping criteria algorithm
The CRC stopping criteria algorithm
For more detailed information on the TCP2, see the
TMS320TCI648x DSP Turbo-Decoder Coprocessor 2
(TCP2) Reference Guide
(literature number
SPRUE10
).
C64x+ Peripheral Information and Electrical Specifications
218
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