WM8959 Wolfson Microelectronics Ltd., WM8959 Datasheet - Page 55

• Manufacturer Part Number: WM8959
• Description: Mobile Multimedia DAC with Dual-mode Class AB/D Speaker Driver
• Manufacturer: Wolfson Microelectronics Ltd.

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Pre-Production
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.
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.
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.
Table 22 DAC Sloping Stopband Filter
R10 (0Ah)
R10 (0Ah)
DAC Control
R10 (0Ah)
DAC Control
REGISTER
ADDRESS
REGISTER
ADDRESS
REGISTER
ADDRESS
5:4
BIT
BIT
8
BIT
9
DAC_SB_FILT
DEEMP
[1:0]
DAC_MONO
LABEL
LABEL
LABEL
00b
DEFAULT
DEFAULT
0b
0b
DEFAULT
DAC De-Emphasis Control
00 = No de-emphasis
01 = 32kHz sample rate
10 = 44.1kHz sample rate
11 = 48kHz sample rate
Selects DAC filter characteristics
0 = Normal mode
1 = Sloping stopband mode
DAC Mono Mix
0 = Stereo
1 = Mono (Mono mix output on
enabled DACs)
DESCRIPTION
DESCRIPTION
DESCRIPTION
PP, May 2008, Rev 3.1
WM8959
55