Production Data
WM8945
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
AUX2_TO_OUTL
_ATTEN
0
AUX2 Audio Input to Left Output
Mixer attenuation
1
0 = 0dB
1 = -6dB attenuation
AUX1_TO_OUTL
_ATTEN
0
AUX1 Audio Input to Left Output
Mixer attenuation
0
0 = 0dB
1 = -6dB attenuation
Table 30 Line Output Mixer (MIXOUTL) Control
SPEAKER PGA MIXER CONTROL
The Speaker PGA mixer controls are described in Table 31 for the left channel (MIXSPKL) and Table
32 for the right channel (MIXSPKR). These allow any of the DAC, Inverted DAC, AUX1/2 and one of
the ADC Bypass signals to be mixed. The output of each PGA mixer can be muted also, using the
SPKL_MIX_MUTE and SPKR_MIX_MUTE bits.
Note that the output from the Speaker PGA mixer is also controlled by the Speaker PGA Volume
control and the Speaker Output control described in the following sections.
Care should be taken when enabling more than one path to the Speaker PGA mixers in order to avoid
clipping. The gain of each input path is adjustable using a selectable -6dB control in each path to
facilitate this.
Note that the attenuation control field DACL_TO_PGAL_ATTEN controls the DAC and the Inverted
DAC mixer paths to the Left Speaker PGA mixer. Similarly, the DACL_TO_PGAR_ATTEN controls
the DAC and the Inverted DAC mixer paths to the Right Speaker PGA mixer. Note that the DAC input
level may also be controlled by the DAC digital volume control – see “Digital to Analogue Converter
(DAC)” for further details.
When the AUX1 or AUX2 pin is used as an audio input, that pin must be configured for audio using
the AUX1_AUDIO or AUX2_AUDIO register bits. These bits are defined in Table 2 (see “Analogue
Input Signal Path”).
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R3 (03h)
SPKL_MIX_
MUTE
1
Left Speaker PGA Mixer Mute
0 = Disable Mute
4
Power
Management
1
1 = Enable Mute
R43 (2Bh)
BYPL_TO_PGAL
0
0
0
0
Left Input PGA (ADC bypass) to
Left Speaker PGA Mixer select
6
5
3
1
SPK mixer
control 1
0 = Disabled
1 = Enabled
MDACL_TO_
PGAL
Inverted Left DAC to Left Speaker
PGA Mixer select
0 = Disabled
1 = Enabled
DACL_TO_PGAL
AUX2_TO_PGAL
Left DAC to Left Speaker PGA
Mixer select
0 = Disabled
1 = Enabled
AUX2 Audio Input to Left Speaker
PGA Mixer select
0 = Disabled
1 = Enabled
PD, May 2011, Rev 4.1
53
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
