CDB6420 Cirrus Logic Inc, CDB6420 Datasheet - Page 18

• 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 3
AErle - Acoustic ERLE Threshold
The CS6420 will allow full-duplex operation only
when the Acoustic ERLE it provides exceeds AEr-
le. See also AFNse. See Glossary for a definition
of ERLE.
AFNse - Acoustic Full-Duplex Noise Threshold
AFNse works in conjunction with AErle to deter-
mine when the CS6420 should transition into full-
duplex operation. If the current noise level at the
near-end input is greater than AFNse, then AErle is
18
b15
15-14
13-12
11-10
Bits
9-8
7-6
5-4
AErle
3
00
b14
* Denotes reset value
TSBias
AFNse
TSThd
THDet
b13
Name
HHold
TSAtt
AErle
AFNse
00
b12
b11
Tx Half-Duplex Detection Threshold
THDet
AEC Full-Duplex Noise Threshold
00
Hold in Half-Duplex on Howl
Tx Suppression Attenuation
Tx Suppression Threshold
b10
AEC ERLE Threshold
Tx Suppression Bias
Table 6. Register 3 Bit Definitions
b9
Function
TSAtt
00
b8
b7
TSBias
used to determine if full-duplex is allowed. If the
noise level is below the level of AFNse, the
CS6420 uses an internal estimate of asymptotic
performance to determine whether or not to transi-
tion to full-duplex. If AFNse is zero, AErle is al-
ways used as the full-duplex criterion. The other
values exist for cases where there may not be an
acoustic path to converge to.
THDet - Transmit Half-Duplex Detection
00
b6
b5
TSThd
00
Word
b4
00*
00*
00*
00*
00*
00*
01
10
11
01
10
11
01
10
11
01
10
11
01
10
11
01
10
11
0*
1
HHold
b3
0
b2
1
1
Operation
reserved
reserved
reserved
reserved
reserved
reserved
disable
enable
-42 dB
-54 dB
24 dB
18 dB
30 dB
18 dB
12 dB
24 dB
18 dB
15 dB
21 dB
15 dB
12 dB
zero
5 dB
3 dB
6 dB
9 dB
b1
CS6420
1
1
DS205PP2
b0
0
0