[AK4634]
■ Input Digital Volume (Manual Mode)
When ADCPF bit = “1” and ALC1 bit = “0”, ALC block becomes an input digital volume (manual mode). The digital
volume’s gain is set by IVOL7-0 bits as shown in Table 22. The IVOL value is changed at zero cross or zero cross time
out. The zero crossing timeout period is set by ZTM1-0 bits.
IVOL7-0bits
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 22. Input Digital Volume Setting
When writing to the IVOL7-0 bits continually, the control register should be written in an interval more than zero
crossing timeout. If not, zero crossing counter could be reset at each time and volume is not be changed. However, it could
be ignored when writing the same register value as the last time. At this time, zero crossing counter is not reset, so it can
be written in an interval less than zero crossing timeout.
Rev. 0.5
2007/10
- 41 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
