RS8973 Mindspeed Technologies, RS8973 Datasheet - Page 59

• Manufacturer Part Number: RS8973
• Description: Single-chip Sdsl/hdsl Transceiver
• Manufacturer: Mindspeed Technologies

RS8973
Single-Chip SDSL/HDSL Transceiver
negate_symbol
symbol_delay[2:0]
adapt_coefficients
zero_coefficients
zero_output
adapt_gain
adapt_coefficents
zero_coefficients
zero_output
adapt_gain
N8973DSD
0x09—Nonlinear Echo Canceller Modes Register (nonlinear_ec_modes)
0x0A—Decision Feedback Equalizer Modes Register (dfe_modes)
negate_symbol symbol_delay[2] symbol_delay[1] symbol_delay[0]
—
7
7
Negate Symbol—Read/write control bit which, when set, inverts (2s complement) the receive
signal path at the output of the nonlinear echo canceller. When cleared, the signal path is
unaffected. This function is independent of all other NEC mode settings.
Symbol Delay—Read/write binary field which specifies the number of symbol delays inserted
in the transmit symbol input path.
Adapt Coefficients—Same function as LEC Modes Register [linear_ec_modes; 0x08].
Zero Coefficients—Same function as LEC Modes Register.
Zero Output—Same function as LEC Modes Register.
Adaptation Gain—Read/write control bit which specifies the adaptation gain. When
adapt_gain is set, the adaptation gain is eight times higher than when cleared.
Adapt Coefficients—Read/write control bit which enables coefficient adaptation when set;
disables/freezes adaptation when cleared. Coefficient values are preserved when adaptation is
disabled.
Zero Coefficients—Read/write control bit which continuously zeros all coefficients when set;
allows normal coefficient updates, if enabled, when cleared.
Zero Output—Read/write control bit which, when set, zeros the filter output before subtraction
from the FFE output. Achieves the affect of disabling or bypassing the equalization function.
Does not disable coefficient adaptation. When cleared, the normal equalizer operation is
performed.
Adaptation Gain—Read/write control bit which specifies the adaptation gain. When
adapt_gain is set, the adaptation gain is eight times higher than when cleared.
—
6
6
—
5
5
Preliminary Information
—
4
4
Conexant
coefficients
coefficients
adapt_
adapt_
3
3
zero_coefficients
zero_coefficients
2
2
zero_output
zero_output
3.3 Register Description
1
1
3.0 Registers
adapt_gain
adapt_gain
0
0
3-13