wm8961 Wolfson Microelectronics plc, wm8961 Datasheet - Page 39

• Manufacturer Part Number: wm8961
• Description: Ultra-low Power Stereo Codec With 1w Stereo Class D Speaker Drivers And Ground Referenced Headphone Drivers
• Manufacturer: Wolfson Microelectronics plc

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WM8961
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.
Table 21 DAC De-Emphasis Control
DAC MONO MIX
In normal operation, the left and right channel digital audio data is converted to analogue in two
separate DACs. There is a mono-mix mode where the two audio channels are mixed together digitally
and then converted to analogue using only one DAC (enabled DAC), while the other DAC must be
disabled.
Only one DAC must be enabled in order to use this function.
A DAC digital mono-mix mode can be enabled using the DMONOMIX register bit.
To prevent clipping, a -6dB attenuation is automatically applied to the mono mix.
Table 22 DAC Mono Mix
DAC OUTPUT PHASE
The DAC output defaults to be non-inverted. Setting DACPOL[0] bit will invert the left DAC output
phase and setting DACPOL[1] bit will invert the right DAC output phase.
Table 23 DAC Phase Invert Select
DAC SLOPING STOP-BAND FILTER
Two DAC filter types are available, selected by the register bit DACSLOPE. When operating at lower
sample rates (e.g. during voice communication) it is recommended that the sloping stop-band filter
type is selected (DACSLOPE =1) to reduce out-of-band noise which can be audible at low DAC
sample rates. See "Digital Filter Characteristics" section for details of DAC filters characteristics.
Table 24 DAC Sloping Stop-band Filter
R5 (05h)
ADC and DAC
Control (1)
R23 (17h)
Additional
Control (1)
R6 (06h)
ADC and DAC
Control (2)
R6 (06h) ADC &
DAC Control 2
REGISTER
REGISTER
REGISTER
ADDRESS
ADDRESS
ADDRESS
REGISTER
ADDRESS
BIT
6:5
BIT
2:1
BIT
1
BIT
4
DACPOL[1:0]
DACSLOPE
DEEMPH
[1:0]
LABEL
DMONOMIX
LABEL
LABEL
LABEL
00
DEFAULT
DEFAULT
DEFAULT
00
0
0
DEFAULT
De-Emphasis Control
11 = 48kHz sample rate
10 = 44.1kHz sample rate
01 = 32kHz sample rate
00 = No de-emphasis
00 : Both Channels normal polarity
01 : Left Channel Inverted
10 : Right Channel Inverted
11 : Both Channels Inverted
DAC Data invert
Selects DAC filter characteristics
0 = Normal mode
1 = Sloping stop-band mode
DAC Mono Mix
0 = Stereo
1 = Mono (Mono mix output on
enabled DAC)
DESCRIPTION
DESCRIPTION
DESCRIPTION
PP, August 2009, Rev 3.1
DESCRIPTION
Pre-Production
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