3Com 56k User's Manual And Reference page 72

Register Default
S32 (Continued)
S33 0
S34 0
68
Technical Reference
Function
Bit Value Result
4 16 Disable 33,600 bps and 31,200bps in V.34 modulation
5 32 Disable 56K modulation
6 64 Disable V.90 modulation.
7 128 Reserved.
Bit-mapped register setup
To set the register, see the instructions for S13
Bit Value Result
0 1 Disable 2400 symbol rate
1 2 Disable 2743 symbol rate
2 4 Disable 2800 symbol rate
3 8 Disable 3000 symbol rate
4 16 Disable 3200 symbol rate
5 32 Disable 3429 symbol rate
6 64 Reserved
7 128 Disable shaping
Bit-mapped register setup
To set registers, see instructions for S13
Bit Value Result
0 1 Disable 8S-2D trellis encoding
1 2 Disable 16S-4D trellis encoding