[AK4634]
■ Output Digital volume (Manual mode)
When ADCPF bit = “0” and ALC2 bit = “0”, ALC block become an output digital volume (manual mode). The digital
volume’s gain is set by OVOL7-0 bits as shown in Table 23. The OVOL7-0 bits value are reflected to this output volume
at zero cross or zero cross time out. The zero crossing timeout period is set by ZTM1-0 bits.
OVOL7-0bits
GAIN(0dB)
Step
F1H
F0H
EFH
:
92H
91H
90H
:
+36.0
+35.625
+35.25
:
+0.375
0.0
0.375dB
(default)
-0.375
:
2H
1H
-53.625
-54.0
MUTE
0H
Table 23 Output Digital Volume Setting
When writing to the OVOL7-0 bits continually, the control register should be written by an interval more than zero
crossing timeout. If not, a zero crossing counter is reset at each time and the volume will not be changed. However, It
could be ignored when writing a same register value as the last time. At this time, zero crossing counter is not reset, so it
can be written by an interval less than zero crossing timeout.
■ Output Digital Volume2
AK4634 has 4 steps output volume in addition to the volume setting by OVOL7-0 bits. This volume is set by DATT1-0
bits as shown in Table 24.
DATT1-0bits
GAIN(0dB)
Step
0H
1H
2H
3H
0.0
-6.0
-12.0
-18.1
(default)
6.0dB
Table 24. Output Digital Volume2 Setting
MS0983-E-00
2008/07
- 42 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
