WM8777
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ATTENUATOR CONTROL MODE
Setting the ATC register bit causes the left channel attenuation settings to be applied to both left and
right channel DACs from the next audio input sample. No update to the attenuation registers is
required for ATC to take effect. When the ATC register bit is unset the right channel gain is applied
form the new audio input sample.
REGISTER ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
Attenuator Control
0 = All DACs use attenuations as
programmed.
(15h)
1
DACATC
0
DAC Attenuation Control
1 = Right channel DACs use
corresponding left DAC attenuations
Table 58 DAC Attenuation Register (DACATC)
ANALOGUE VOLUME CONTROL
The DAC volume may be adjusted independently in both the analogue and digital domain using
separate volume control registers.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
(00h)
6:0
FRONTLA
[6:0]
1101011
(0dB)
0
Analogue Attenuation control for FRONTL in 1dB steps. See Table
60.
Analogue
Attenuation
FRONTL
7
8
FRONTL zero cross detect enable
FRONTLZCEN
0 = zero cross disabled
1 = zero cross enabled
UPDATE
Not latched
Controls simultaneous update of all Analogue Attenuation Latches
0 = Store FRONTL in intermediate latch (no change to output)
1 = Store FRONTL and update attenuation on all channels.
(01h)
6:0
7
FRONTRA
[6:0]
1101011
(0dB)
0
Analogue Attenuation control for FRONTR in 1dB steps. See Table
60.
Analogue
Attenuation
FRONTR
FRONTR zero cross detect enable
FRONTRZCEN
0 = zero cross disabled
1 = zero cross enabled
8
UPDATE
Not latched
Controls simultaneous update of all Analogue Attenuation Latches
0 = Store FRONTR in intermediate latch (no change to output)
1 = Store FRONTR and update attenuation on all channels.
Analogue Attenuation control for CNTR in 1dB steps. See Table 60.
(02h)
6:0
7
CNTRA
[6:0]
1101011
(0dB)
Analogue
Attenuation CNTR
CNTRZCEN
0
CNTR zero cross detect enable
0 = zero cross disabled
1 = zero cross enabled
8
UPDATE
Not latched
Controls simultaneous update of all Analogue Attenuation Latches
0 = Store CNTR in intermediate latch (no change to output)
1 = Store CNTR and update attenuation on all channels.
Analogue Attenuation control for LFE in 1dB steps. See Table 60.
(03h)
6:0
7
LFEA
[6:0]
1101011
(0dB)
Analogue
Attenuation
LFE
LFEZCEN
0
LFE zero cross detect enable
0 = zero cross disabled
1 = zero cross enabled
8
UPDATE
Not latched
Controls simultaneous update of all Analogue Attenuation Latches
0 = Store LFE in intermediate latch (no change to output)
1 = Store LFE and update attenuation on all channels.
PP Rev 1.94 November 2004
60
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
