[AK4679]
■ Digital Volume for Recording of Received Voice (DATT-B)
The AK4679 has a digital output volume control (DATT-B: 128 levels, 0.5dB step, Mute) for recording of received voice.
The volume can be set by the BVL6-0 bits. This volume is included in SRCAI blocks. The output data of SRCAI is
changed from +6 to –57dB or MUTE. This volume control is in common for left and right channels. This volume has a
soft transit function. The OVTMB bit sets the transition time between set values of BVL6-0 bits as either 128/fs or 256/fs
(Table 71). When OVTMB bit = “1”, a soft transition between the set values occurs (256 levels). It takes 256/fs (=5.8ms
@ fs=44.1kHz, PMMIX bit = “1”) from 00H (+6dB) to 7FH (MUTE).
BVL6-0 bits
Gain
+6.0dB
+5.5dB
+5.0dB
:
Step
00H
01H
02H
:
0CH
:
0.5dB
0dB
:
(default)
7DH
7EH
7FH
−56.5dB
−57.0dB
MUTE (−∞)
Table 70. Digital Volume B Table
Transition time between BVL6-0 bits = 00H and 7FH
OVTMB bit
Setting
128/fs
256/fs
fs=8kHz
16ms
32ms
fs=44.1kHz
2.9ms
0
1
5.8ms
(default)
(PMMIX bit = “0”: fs = SYNCB Frequency, PMMIX bit = “1”: fs = LRCK Frequency)
Table 71. Transition Time Setting of Digital Output Volume B
■ Digital Volume for Received Voice (DATT-C)
The AK4679 has a digital output volume control (DATT-C: 128 levels, 0.5dB step, Mute) for recording of received voice.
The volume can be set by the CVL6-0 bits. The volume range is from +6 to –57dB or MUTE. This volume control is in
common for left and right channels. This volume has a soft transit function. The OVTMB bit sets the transition time
between set values of CVL6-0 bits as either 128/fs or 256/fs (Table 73). When OVTMB bit = “1”, a soft transition
between the set values occurs (256 levels). It takes 256/fs (=5.8ms @ fs =44.1kHz, PMMIX bit = “1”) from 00H (+6dB)
to 7FH (MUTE).
CVL6-0 bits
Gain
+6.0dB
+5.5dB
+5.0dB
:
Step
00H
01H
02H
:
0CH
:
0.5dB
0dB
:
(default)
7DH
7EH
7FH
−56.5dB
−57.0dB
MUTE (−∞)
Table 72. Digital Volume C Table
Transition time between CVL6-0 bits = 00H and 7FH
OVTMB bit
Setting
128/fs
256/fs
fs=8kHz
16ms
32ms
fs=44.1kHz
2.9ms
0
1
5.8ms
(default)
(PMMIX bit = “0”: fs = SYNCB Frequency, PMMIX bit = “1”: fs = LRCK Frequency)
Table 73. Transition Time Setting of Digital Output Volume C
MS1402-E-06
2013/02
- 103 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
