[AK4646]
3. The Volume at the ALC Operation
The current volume value at the ALC operation is reflected by VOL7-0 bits. It is enable to check the current volume value
with reading the register value of VOL7-0 bits.
VOL7-0bits
GAIN(0dB)
F1H
F0H
EFH
:
+36.0
+35.625
+35.25
:
C5H
:
+19.5
:
92H
91H
90H
:
+0.375
0.0
-0.375
:
2H
1H
0H
-53.625
-54.0
MUTE
Table 31. Value of VOL7-0 bits
4. Example of ALC Operation
Table 32 and Table 33 show the examples of the ALC setting for recording and playback path.
fs=8kHz
fs=44.1kHz
Operation
Register Name Comment
Data
01
0
Operation
Data
01
0
LMTH1-0
ZELMN
ZTM1-0
Limiter detection Level
−4.1dBFS
Enable
32ms
−4.1dBFS
Enable
23.2ms
Limiter zero crossing detection
Zero crossing timeout period
Recovery waiting period
01
11
WTM2-0
*WTM2-0 bits should be the same data
as ZTM1-0 bits
001
32ms
100
46.4ms
IREF7-0
IVL7-0,
IVR7-0
Maximum gain at recovery operation
E1H
E1H
+30dB
+30dB
E1H
E1H
+30dB
+30dB
Gain of IVOL
LMAT1-0
LFST
RGAIN1-0
RFST1-0
ALC1
Limiter ATT step
Fast Limiter Operation
Recovery GAIN step
Fast Recovery Speed
ALC enable
00
1
00
00
1
1 step
ON
1 step
4 times
Enable
00
1
00
00
1
1 step
ON
1 step
4 times
Enable
Table 32. Example of the ALC setting (Recording)
MS0557-E-05
2011/01
- 41 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
