wm8918 Wolfson Microelectronics plc, wm8918 Datasheet - Page 61

• Manufacturer Part Number: wm8918
• Description: Ultra Low Power Dac For Portable Audio Applications
• Manufacturer: Wolfson Microelectronics plc

Production Data
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Table 33 DAC Soft-Mute Control
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 whichever DAC is enabled. To prevent clipping, a -6dB attenuation is automatically
applied to the mono mix.
The mono mix is only supported when one or other DAC is disabled. When the mono mix is selected,
then the mono mix is output on the enabled DAC only; there is no output from the disabled DAC. If
DACL_ENA and DACR_ENA are both set, then stereo operation applies.
Table 34 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” for details of de-emphasis filter
characteristics.
Table 35 DAC De-Emphasis Control
R33 (21h)
DAC Digital 1
R33 (21h)
DAC Digital 1
R33 (21h)
DAC Digital 1
REGISTER
REGISTER
REGISTER
ADDRESS
ADDRESS
ADDRESS
BIT
10
BIT
BIT
2:1
9
3
12
DAC_MUTERA
DAC_UNMUTE
DAC_MUTE
DEEMPH [1:0]
DAC_MONO
_RAMP
LABEL
LABEL
LABEL
TE
DEFAULT
DEFAULT
DEFAULT
0
0
1
00
0
DAC Soft Mute Ramp Rate
0 = Fast ramp (fs/2, maximum ramp
time is 10.7ms at fs=48k)
1 = Slow ramp (fs/32, maximum ramp
time is 171ms at fs=48k)
DAC Soft Mute Mode
0 = Disabling soft-mute
(DAC_MUTE=0) will cause the DAC
volume to change immediately to
DACL_VOL and DACR_VOL settings
1 = Disabling soft-mute
(DAC_MUTE=0) will cause the DAC
volume to ramp up gradually to the
DACL_VOL and DACR_VOL settings
DAC Soft Mute Control
0 = DAC Un-mute
1 = DAC Mute
DAC Mono Mix
0 = Stereo
1 = Mono (Mono mix output on
enabled DAC)
DAC De-Emphasis Control
00 = No de-emphasis
01 = 32kHz sample rate
10 = 44.1kHz sample rate
11 = 48kHz sample rate
PD, Rev 4.0, September 2010
DESCRIPTION
DESCRIPTION
DESCRIPTION
WM8918
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