CS6420-CS datasheet(15/52 Pages) CIRRUS

15 / 52 page

CS6420

DS205PP2

network echo. By default, the receive suppression

function is enabled.

Taps - AEC/NEC Tap Allocation

The CS6420 has a total of 63.5 ms of echo canceller

taps that it can partition for use by the network and

acoustic echo cancellers. By default, the CS6420

allocates 39.5 ms for the AEC and 24 ms for the

NEC. Some applications will never have a network

echo path, and so should allocate all taps for the

AEC. See NErle and NFNse in Register 2, and

AErle and AFNse in Register 3 for more options

when an echo path is nonexistent.

NCC - Network Coefficient Control

The NEC adaptive filter’s coefficients are con-

trolled by NCC. See ACC in Register 0 for more

details. The default setting for NCC is Normal

mode.

TVol - Transmit Volume Control

Volume in the transmit path is controlled by TVol.

Like receive volume, the transmit volume is con-

trolled by an AGC. See RVol in Register 0 for more

details. The default setting for the transmit refer-

ence level is +0 dB.

RGain - Receive Analog Gain

RGain selects the amount of additional on-chip an-

alog gain to be supplied to the network input of the

CS6420. A programmable gain amplifier (PGA)

exists before each ADC which allows 0 dB, 6 dB,

9.5 dB, or 12 dB of gain to be added to the signal

path. The network side defaults to 0 dB of gain.

Note: Changing the analog gain will change the full-

scale voltage as applied to the input pin. Make

sure that the ADC input does not clip with the gain

stage on.

CS6420-CS Datasheet(PDF) 15 Page - Cirrus Logic