English
Language : 

AK4679EG Datasheet, PDF (103/220 Pages) Asahi Kasei Microsystems – 24bit Stereo CODEC with DSP and MIC/RCV/HP/SPK/LINE-AMP
◁
[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
Step
00H
+6.0dB
01H
+5.5dB
02H
+5.0dB
:
0CH
:
0dB
0.5dB
:
:
7DH
−56.5dB
7EH
−57.0dB
7FH
MUTE (−∞)
Table 70. Digital Volume B Table
(default)
OVTMB bit
Transition time between BVL6-0 bits = 00H and 7FH
Setting
fs=8kHz
fs=44.1kHz
0
128/fs
16ms
2.9ms
1
256/fs
32ms
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
Step
00H
+6.0dB
01H
+5.5dB
02H
+5.0dB
:
0CH
:
0dB
0.5dB
:
:
7DH
−56.5dB
7EH
−57.0dB
7FH
MUTE (−∞)
Table 72. Digital Volume C Table
(default)
OVTMB bit
Transition time between CVL6-0 bits = 00H and 7FH
Setting
fs=8kHz
fs=44.1kHz
0
128/fs
16ms
2.9ms
1
256/fs
32ms
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
- 103 -
2013/02
 ▷