Texas Instruments TURBO-DECODER COPROCESSOR 2 TMS320C6457 DSP Benutzerhandbuch
10
Output Parameters
11
Events Generation
Write to
TCPEND
Write to
TCPEXE
TCPEXE
Soft
reset
XEVT
Write
input
params
XEVT
XEVT
Write
input
data
coefficients
interleaver
Write
MAP0
decode
MAP
decode
REVT
REVT
XEVT
decisions
hard
Read
registers
Read
output
T
CPU/DMA
operations
TCP
operations
Output Parameters
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•
The EMAXSTR bit can be enabled or disabled in TCPIC3, 0 = max star disabled (enable Max
Log-MAP, 1 = max star enabled (enable log MAP)).
Log-MAP, 1 = max star enabled (enable log MAP)).
•
The minimum number of iterations (MINIT bits in TCPIC3) should be selected as a function of the
overall system performance (minimum iterations 1 to 31).
overall system performance (minimum iterations 1 to 31).
•
The INPUTSIGN bit can be enabled or disabled in TCPIC3 (0 = Use channel input data as is, 1 =
multiply channel input data by -1).
multiply channel input data by -1).
•
The OUTORDER bit can be enabled or disabled in TCPIC3 (0 = output bit ordering from 0 to 31, 1 =
output bit ordering from 31 to 0).
output bit ordering from 31 to 0).
The TAIL1, TAIL2, TAIL3, TAIL4, TAIL5, TAIL6 bits should be programmed as described in
through
, respectively.
Table 45. Input Configuration Parameters Settings in Shared-Processing (SP)
Mode
Bit field
Register
Value
OPMOD
TCPIC0
OPMOD = 2 for first subframe
OPMOD = 4 for middle subframe
OPMOD = 6 for last subframe
OPMOD = 4 for middle subframe
OPMOD = 6 for last subframe
INTER
TCPIC0
INTER = 0
OUTF
TCPIC0
OUTF = 0
The various output parameters are described in
through
. These parameters
provide useful information when the stopping criteria are enabled.
A TCP2 transmit event (TCPXEVT) and TCP2 receive event (TCPREVT) are generated as shown in
for standalone (SA) mode and as shown in
for shared-processing (SP) mode
(example of 2 subframes).
Figure 100. TCP2 Events Generation in Standalone (SA) Mode
TMS320C6457 Turbo-Decoder Coprocessor 2
74
SPRUGK1 – March 2009