[AK4634]
The following registers must not be changed during the ALC operation. These bits should be changed, after the ALC
operation is finished by ALC1 bit = ALC2 bit = “0” or PMPFIL bit = “0”. When ALC is restarted, after ALC1 bit and
ALC2 bit set to “0” or PMPFIL bit sets to “0”, the waiting time of zero crossing timeout is not needed.
LMTH1-0, LMAT1-0, WTM2-0, ZTM1-0, RGAIN1-0, IREF7-0/OREF7-0, ZELM, RFST1-0, LFST
Example:
Limiter = Zero crossing Enable
Manual Mode
Recovery Cycle = 16ms@8kHz
Limiter and Recovery Step = 1
WR (ZTM1-0, WTM2-0)
WR (IREF7-0/OREF5-0)
WR (IVOL7-0/OVOL7-0)
LFST = 1
Maximum Gain = +19.5dB
Limiter Detection Level = −4.1dBFS
ALC1 bit = “1”
*1
(1) Addr=06H, Data=00H
(2) Addr=08H, Data=C5H
(3) Addr=09H, Data=C5H
WR (RGAIN1, LMTH1,RFST1-0)
WR (LFST,LMAT1-0, RGAIN0, ZELMN, LMTH0)
WR (ALC1= “1”)
*2
ALC Operation
(4) Addr=0BH, Data=28H
(5) Addr=07H, Data=A1H
Note : WR : Write
*1: The value of volume at starting should be the same or smaller than REF’s.
*2: When setting ALC1 bit or ALC2 bit to “0”, the operation is shifted to manual mode after passing the zero crossing
time set by ZTM1-0 bits.
Figure 39. Registers set-up sequence at the ALC operation
MS0983-E-00
2008/07
- 48 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
