ak4671 AKM Semiconductor, Inc., ak4671 Datasheet - Page 70

• Manufacturer Part Number: ak4671
• Description: Stereo Codec With Mic/rcv/hp-amp
• Manufacturer: AKM Semiconductor, Inc.

3. Example of ALC Operation
Table 31
MS0666-E-00
Register Name
LMTH1-0
ZELMN
ZTM1-0
WTM2-0
REF7-0
IVL7-0,
IVR7-0
LMAT1-0
RGAIN1-0
RFST1-0
ALC
Register Name
LMTH1-0
ZELMN
ZTM1-0
WTM2-0
REF5-0
IVL7-0,
IVR7-0
LMAT1-0
RGAIN1-0
RFST1-0
ALC
and
Table 32
Comment
Limiter detection Level
Limiter zero crossing detection
Zero crossing timeout period
* ZTM1-0 bits should be equal to or
shorter than WTM2-0 bits.
Recovery waiting period
Maximum gain at recovery operation
Gain of IVOL
Limiter ATT step
Recovery GAIN step
Fast Recovery Speed
ALC enable
Comment
Limiter detection Level
Limiter zero crossing detection
Zero crossing timeout period
Recovery waiting period
*WTM2-0 bits should be the same or
Maximum gain at recovery operation
Gain of IVOL
Limiter ATT step
Recovery GAIN step
Fast Recovery Speed
ALC enable
longer data as ZTM1-0 bits
show the examples of the ALC setting for mic recording and playback, respectively.
Table 31. Example of the ALC setting (Recording Path)
Table 32. Example of the ALC setting (Playback Path)
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A1H
Data
E1H
E1H
Data
91H
001
001
01
01
00
00
00
01
01
00
00
00
0
1
0
1
fs=8kHz
fs=8kHz
− 4.1dBFS
− 4.1dBFS
Operation
Operation
4 times
4 times
Enable
+30dB
+30dB
Enable
Enable
Enable
1 step
1 step
1 step
1 step
32ms
32ms
32ms
32ms
+6dB
0dB
Data
Data
A1H
E1H
E1H
91H
100
100
01
11
00
00
00
01
11
00
00
00
0
1
0
1
fs=44.1kHz
fs=44.1kHz
− 4.1dBFS
− 4.1dBFS
Operation
Operation
23.2ms
46.4ms
23.2ms
46.4ms
4 times
4 times
Enable
+30dB
+30dB
Enable
Enable
Enable
1 step
1 step
1 step
1 step
+6dB
0dB
[AK4671]
2007/10