CDB6420 Cirrus Logic Inc, CDB6420 Datasheet - Page 15

• Manufacturer Part Number: CDB6420
• Description: Development Kit
• Manufacturer: Cirrus Logic Inc

Specifications of CDB6420

• Silicon Manufacturer: Cirrus Logic
• Application Sub Type: Speakerphone
• Kit Application Type: Audio / Video / TV
• Silicon Core Number: CS6420
• Kit Contents: Board
• Kit Features: Analog And Digital Patch Area
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

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.
DS205PP2
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
15