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WM8591
DAC DIGITAL VOLUME CONTROL
The DAC volume may also be adjusted in the digital domain using independent digital attenuation
control registers
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R3 (03h)
0000011
7:0
LDA[7:0]
11111111
(0dB)
Digital Attenuation data for Left channel DACL in 0.5dB steps. See
Table 11
Digital
Attenuation
8
UPDATED
Not latched
Controls simultaneous update of Attenuation Latches
0: Store LDA in intermediate latch (no change to output)
1: Store LDA and update attenuation on both channels
DACL
R4 (04h)
0000100
7:0
8
RDA[6:0]
11111111
(0dB)
Digital Attenuation data for Right channel DACR in 0.5dB steps. See
Table 11
Digital
Attenuation
DACR
UPDATED
Not latched
Controls simultaneous update of Attenuation Latches
0: Store RDA in intermediate latch (no change to output)
1: Store RDA and update attenuation on both channels.
R5 (05h)
0000101
7:0
8
MDA[7:0]
11111111
(0dB)
Digital Attenuation data for DAC channels in 0.5dB steps. See Table
11
Master
Digital
Attenuation
UPDATED
Not latched
Controls simultaneous update of Attenuation Latches
0: Store gain in intermediate latch (no change to output)
1: Store gain and update attenuation on channels.
(both channels)
L/RDA[7:0]
ATTENUATION LEVEL
00(hex)
-∞ dB (mute)
01(hex)
-127dB
:
:
:
:
:
:
FE(hex)
FF(hex)
-0.5dB
0dB
Table 11 Digital Volume Control Attenuation Levels
The digital volume control also incorporates a zero cross detect circuit which detects a transition
through the zero point before updating the digital volume control with the new volume. This is
enabled by control bit DZCEN.
REGISTER ADDRESS
R7 (07h)
BIT
LABEL
DEFAULT
DESCRIPTION
0
DZCEN
0
DAC Digital Volume Zero Cross
Enable:
0000111
0: Zero cross detect disabled
1: Zero cross detect enabled
DAC Control
DAC OUTPUT PHASE
The DAC Phase control word determines whether the output of the DAC is non-inverted or inverted
REGISTER ADDRESS
R6 (06h)
BIT
LABEL
DEFAULT
DESCRIPTION
1:0
PHASE
[1:0]
00
Bit
0
DAC
Phase
0000110
DACL
DACR
1 = invert
1 = invert
DAC Phase
1
PP Rev 1.0 May 2005
29
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
