Table 13-10 Soft Decision Format - Motorola DSP56305 User Manual

VITERBI CO-PROCESSOR
Chip Description
13.6.4 Soft Decision Format
The module uses soft data in decoding in 8- and 16-bit precision. The 16-bit equalizer
output can be fed gluelessly into the decoder, because the decoder metric computations
are performed on the 8-most significant bits of the symbol-bits value (in the VDR).
Table 13-10 below presents the soft values in both 8 and 16-bit precisions, as being read
or written via a 24-bit VCOP register.
Soft Value
Strong '0'
...
Weak '0'
Neutral value
Weak '1'
...
Strong '1'
13-32

Table 13-10 Soft Decision Format

8-bit Precision
(Symbol Input to Decoder)
0x7F0000
...
0x010000
0x000000
0xFF0000
...
0x800000
DSP56305 User's Manual
16-bit Precision
(Equalizer Output)
0x7FFF00
...
all other values
reserved
...
0x800000
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