Pre-Production
WM8959
DAC MONO MIX
A DAC digital mono-mix mode can be enabled using the DAC_MONO register bit. This mono mix will
be output on the enabled DACs. To prevent clipping, a -6dB attenuation is automatically applied to
the mono mix.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
0b
DESCRIPTION
R10 (0Ah)
9
DAC_MONO
DAC Mono Mix
0 = Stereo
1 = Mono (Mono mix output on
enabled DACs)
Table 20 DAC Mono Mix
DAC DE-EMPHASIS
Digital de-emphasis can be applied to the DAC playback data (e.g. when the data comes from a CD
with pre-emphasis used in the recording). De-emphasis filtering is available for sample rates of
48kHz, 44.1kHz and 32kHz. See "Digital Filter Characteristics" section for details of de-emphasis
filter characteristics.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R10 (0Ah)
5:4
DEEMP
[1:0]
00b
DAC De-Emphasis Control
00 = No de-emphasis
DAC Control
01 = 32kHz sample rate
10 = 44.1kHz sample rate
11 = 48kHz sample rate
Table 21 DAC De-Emphasis Control
DAC SLOPING STOPBAND FILTER
Two DAC filter types are available, selected by the register bit DAC_SB_FILT. When operating at
lower sample rates (e.g. during voice communication) it is recommended that the sloping stopband
filter type is selected (DAC_SB_FILT=1) to reduce out-of-band noise which can be audible at low
DAC sample rates. See "Digital Filter Characteristics" for details of DAC filter characteristics.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R10 (0Ah)
8
DAC_SB_FILT
0b
Selects DAC filter characteristics
0 = Normal mode
DAC Control
1 = Sloping stopband mode
Table 22 DAC Sloping Stopband Filter
PP, May 2008, Rev 3.1
55
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