Texas Instruments TURBO-DECODER COPROCESSOR 2 TMS320C6457 DSP Benutzerhandbuch
32-bit configuration bus
64-bit EDMA3 bus
Turbo-decoder coprocessor (TCP2)
REVT/XEVT
generation
CPU
interrupt
generation
TCP2 control
EDMA3 I/F unit
Memory block
Processing unit
TCP2_INT
TCPXEVT TCPREVT
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Standalone (SA) Mode
Standalone (SA) Mode
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Figure 3. TCP2 Block Diagram
Table 1. Frame Sizes for Standalone (SA) Mode and
Shared-Processing (SP) Mode
Frame Size (F)
TCP2 Mode
40
⇐
F
⇐
20730
Standalone mode
F > 20730
Shared processing
In standalone (SA) mode, the DSP sends the systematic and parity data, and the interleaver table. The
TCP2 then works independently of the DSP (standalone), iterates a defined maximum number of times,
and outputs hard decision data. In this mode, minimum DSP processing is required. A stopping criteria
can be enabled to reduce the processing delay (see
TCP2 then works independently of the DSP (standalone), iterates a defined maximum number of times,
and outputs hard decision data. In this mode, minimum DSP processing is required. A stopping criteria
can be enabled to reduce the processing delay (see
).
shows the SA mode.
The standalone mode is used for frames in which the turbo interleaver length is less than or equal to
20730. In this mode, the systematic, parities, extrinsics, and turbo interleaver data fit within the TCP2
memory, and several iterations of decoding are run within the coprocessor without any DSP intervention.
20730. In this mode, the systematic, parities, extrinsics, and turbo interleaver data fit within the TCP2
memory, and several iterations of decoding are run within the coprocessor without any DSP intervention.
The DSP sets up the EDMA3 to send the systematic and parity data, and the interleaver table (optional).
The TCP2 then works independently of the DSP.
The TCP2 then works independently of the DSP.
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TMS320C6457 Turbo-Decoder Coprocessor 2
SPRUGK1 – March 2009