CDB6420 Cirrus Logic Inc, CDB6420 Datasheet - Page 12

• 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

Register 0
Mic - Microphone Preamplifier Enable
The microphone preamplifier described in the
Acoustic Interface section is enabled by default, but
may be disabled by setting Mic to 0. Refer to the
Acoustic Interface section for more details on us-
ing/disabling the Microphone Preamplifier.
TSD - Transmit Suppression Disable
The Transmit Supplementary Echo Suppression
function is a non-linear echo control mechanism.
The Transmit Suppression will introduce TSAtt
12
13-12
11-10
Bits
b15
Mic
9-5
4-3
15
14
1
TSD
b14
Name
TGain
ACC
RVol
TSD
* Denotes reset value
0
Mic
GB
b13
Microphone Preamplifier Enable
GB
10
b12
Tx Suppression Disable
AEC Coefficient Control
Rx Volume Control
Tx Analog Gain
Graded Beta
b11
Function
ACC
00
b10
Table 3. Register 0 Bit Definitions
b9
b8
00100
RVol
b7
(see Register 3) dB of attenuation into the transmit
path only when there is speech detected in the re-
ceive path and no near-end speech. When only
near-end speech is present, or if there is no speech
in either direction, the suppression attenuation is
removed. By default, the transmit suppression
function is enabled.
GB - Graded Beta
The room-size adjustment scheme called “graded
beta,” provided for the acoustic echo canceller in the
00100*
00000
00001
01010
01011
11101
11110
11111
Word
10*
00*
00*
00
01
11
01
10
11
01
10
11
1*
0*
---
---
---
0
1
b6
b5
b4
TGain
00
disable Tx suppression
enable Tx suppression
b3
disable preamp
enable preamp
0.00 dB/ms
0.75 dB/ms
0.38 dB/ms
0.19 dB/ms
Operation
reserved
Normal
+30 dB
+27 dB
+18 dB
Freeze
-57 dB
-60 dB
9.5 dB
+0 dB
12 dB
Clear
-3 dB
mute
0 dB
6 dB
b2
0
0
CS6420
b1
0
0
DS205PP2
b0
0
0