WM8581
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PP Rev 1.0 March 2006
32
INFINITE ZERO DETECT
Setting the IZD register bit will enable the internal Infinite Zero Detect function:
REGISTER ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R16
DAC CONTROL 2
10h
7 IZD
0 Infinite zero detection circuit control
and automute control
0 = Infinite zero detect automute
disabled
1 = Infinite zero detect automute
enabled
Table 20 IZD Register
With IZD enabled, applying 1024 consecutive zero input samples to a stereo input channel on any
DAC will cause that stereo channel output to be muted. Mute will be removed as soon as either of
those stereo channels receives a non-zero input.
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
7:0
LDA1[7:0] 11111111
(0dB)
Digital Attenuation control for DAC1 Left Channel (DACL1) in 0.5dB
steps. See Table 22
R20
DIGITAL
ATTENUATION
DACL 1
14h
8
UPDATE Not
latched Controls simultaneous update of all Attenuation Latches
0 = Store LDA1 in intermediate latch (no change to output)
1 = Apply LDA1 and update attenuation on all channels
7:0
RDA1[6:0] 11111111
(0dB)
Digital Attenuation control for DAC1 Right Channel (DACR1) in
0.5dB steps. See Table 22
R21
DIGITAL
ATTENUATION
DACR 1
15h
8
UPDATE Not
latched Controls simultaneous update of all Attenuation Latches
0 = Store RDA1 in intermediate latch (no change to output)
1 = Apply RDA1 and update attenuation on all channels.
7:0
LDA2[7:0] 11111111
(0dB)
Digital Attenuation control for DAC2 Left Channel (DACL2) in 0.5dB
steps. See Table 22
R22
DIGITAL
ATTENUATION
DACL 2
16h
8
UPDATE Not
latched Controls simultaneous update of all Attenuation Latches
0 = Store LDA2 in intermediate latch (no change to output)
1 = Apply LDA2 and update attenuation on all channels.
7:0
RDA2[7:0] 11111111
(0dB)
Digital Attenuation control for DAC2 Right Channel (DACR2) in
0.5dB steps. See Table 22
R23
DIGITAL
ATTENUATION
DACR 2
17h
8
UPDATE Not
latched Controls simultaneous update of all Attenuation Latches
0 = Store RDA2 in intermediate latch (no change to output)
1 = Apply RDA2 and update attenuation on all channels.
7:0
LDA3[7:0] 11111111
(0dB)
Digital Attenuation control for DAC3 Left Channel (DACL3) in 0.5dB
steps. See Table 22
R24
DIGITAL
ATTENUATION
DACL3
18h
8
UPDATE Not
latched Controls simultaneous update of all Attenuation Latches
0 = Store LDA3 in intermediate latch (no change to output)
1 = Apply LDA3 and update attenuation on all channels.
7:0
RDA3[7:0] 11111111
(0dB)
Digital Attenuation control for DAC3 Right Channel (DACR3) in
0.5dB steps. See Table 22
R25
DIGITAL
ATTENUATION
DACR3
19h
8
UPDATE Not
latched Controls simultaneous update of all Attenuation Latches
0 = Store RDA3 in intermediate latch (no change to output)
1 = Apply RDA3 and update attenuation on all channels.