CDB6420 Cirrus Logic Inc, CDB6420 Datasheet - Page 48

• 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

AFNse - Acoustic Full-duplex Noise threshold
zero:
-42 dB:
-54 dB:
PCSen - Path-Change Sensitivity
high:
low:
GB - Graded Beta
0.00 dB/ms: use to disable beta grading
0.75 dB/ms: use for acoustically dead rooms (e.g. inside a
0.38 dB/ms: use for "typical" rooms
0.19 dB/ms: use for very acoustically live rooms (e.g. glass
Taps - allocation of filter Taps
55.5ms/---: allocate all taps to Acoustic canceller (disables
47.5ms/16ms:use for short Network path echo durations or
38.5ms/24ms:use for typical Network path echo durations
31.5ms/32ms:use for long Network path echo durations (note
TSD - Transmit Suppression Disable
checked:
unchecked
TSThd - Transmit Suppression Threshold
15 dB:
12 dB:
9 dB:
48
use AErle as sole criterion to transition to full-
duplex.
echo path may not exist, so go to full-duplex
when noise level is below -42 dB (easy) and in-
ternal determination of path/no path is complete
echo path may not exist, so go to full-duplex
when noise level is below -54 dB (hard) and in-
ternal determination of path/no path is complete
more sensitive to near end path changes (on rare
occasions may briefly drop into half-duplex
during doubletalk)
less sensitive to path changes and more robust
to doubletalk
car)
or tile walls, no carpet, etc.)
Network canceller)
for longer Acoustic path
that Acoustic performance may suffer)
disable transmit suppression
enable transmit suppression
need 15 dB ERLE at acoustic canceller to dis-
criminate between speech and echo
less sensitive to near end speech (more prone to
suppressing near-end speech)
least sensitive to near end speech (most prone to
suppressing near-end speech)
TSAtt - Transmit Suppression Attenuation level
18 dB:
12 dB:
24 dB:
TSBias - Transmit Suppression Bias
18 dB:
15 dB:
21 dB:
TGain - Transmit ADC analog Gain
0 dB, 6 dB, 9.5 dB, 12 dB:
Mic - Microphone preamplifier select
API:
APO:
Reset Button
Cold Reset, Default:
Warm Reset, Default:
Cold Reset, Current:
Warm Reset, Current:
Power Down:
Power Up, Cold Reset, Current:
Power Up, Warm Reset, Current:
default
use if noise modulation caused by suppression
is annoying and residual echo is not perceptible
use if residual echo after suppression is percep-
tible
default
harder for near end to break in. See CS6420
datasheet for details
easier for near end to break in. See CS6420
datasheet for details
set gain of the ADC at API/APO
ADC input is taken from API/MICIN through
34 dB amplifier (HDR1 on board must be set to
PREAMP ON)
ADC input is taken from APO/APO_IN (HDR1
on board must be set to PREAMP OFF)
cold reset to default register values
warm reset to default register values
cold reset to register values indicated by con-
trols
warm reset to register values indicated by con-
trols
hold CS6420 RST low to force low power
mode
bring CS6420 RST high; restore register values
indicated by controls
bring CS6420 RST high; warm reset and re-
store register values indicated by controls
CDB6420
DS205DB1