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WM8983
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R10
DAC Control
0
DACPOL
0
Left DAC output polarity:
0 = non-inverted
1 = inverted (180 degrees phase shift)
Right DAC output polarity:
0 = non-inverted
1
2
3
6
DACRPOL
AMUTE
0
0
0
0
1 = inverted (180 degrees phase shift)
Automute enable
0 = Amute disabled
1 = Amute enabled
DACOSR
SOFTMUTE
DAC oversampling rate:
0 = 64x (lowest power)
1 = 128x (best performance)
Softmute enable:
0 = Enabled
1 = Disabled
Table 20 DAC Control Register
The digital audio data is converted to oversampled bit streams in the on-chip, true 24-bit digital
interpolation filters. The bitstream data enters the multi-bit, sigma-delta DACs, which convert it to a
high quality analogue audio signal. The multi-bit DAC architecture reduces high frequency noise and
sensitivity to clock jitter. It also uses a Dynamic Element Matching technique for high linearity and
low distortion.
The DAC output phase defaults to non-inverted. Setting DACLPOL will invert the DAC output phase
on the left channel and DACRPOL inverts the phase on the right channel.
AUTO-MUTE
The DAC has an auto-mute function which applies an analogue mute when 1024 consecutive zeros
are detected. The mute is released as soon as a non-zero sample is detected. Auto-mute can be
disabled using the AMUTE control bit.
DIGITAL HI-FI DAC VOLUME (GAIN) CONTROL
The signal volume from each Hi-Fi DAC can be controlled digitally. The gain range is –127dB to 0dB
in 0.5dB steps. The level of attenuation for an eight-bit code X is given by:
0.5 × (X-255) dB for 1 ≤ X ≤ 255;
MUTE for X = 0
PP Rev 1.1 August 2005
39
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
