wm8770 Wolfson Microelectronics plc, wm8770 Datasheet - Page 28

• Manufacturer Part Number: wm8770
• Description: 24-bit, 192khz 8-channel Codec With Volume Control
• Manufacturer: Wolfson Microelectronics plc

WM8770
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at 48kHz sampling rate. When MUTE (lower trace) is asserted, the output (upper trace) begins to
decay exponentially from the DC level of the last input sample. The output will decay towards V
with a time constant of approximately 64 input samples. If MUTE is applied to all channels for 1024
or more input samples the DAC will be muted if IZD is set. When MUTE is de-asserted, the output
will restart immediately from the current input sample.
Note that all other means of muting the DAC channels: setting the PL[3:0] bits to 0, setting the
PDWN bit or setting attenuation to 0 will cause much more abrupt muting of the output.
Each ADC channel also has an individual mute control bit, which mutes the input to the ADC. In
addition both channels may be muted by setting ADCMUTE.
The Record outputs may be enabled by setting RECEN, where RECEN enables the REC1L and
REC1R outputs.
Figure 24 Application and Release of Soft Mute
Figure 24 shows the application and release of MUTE whilst a full amplitude sinusoid is being played
11001
ADC Mute
11001
ADC Mute Left
11010
ADC Mute Right
10100
Mute Control
REGISTER ADDRESS
REGISTER ADDRESS
-0.5
-1.5
-2.5
1.5
0.5
-1
-2
1
0
0
0.001
BIT
BIT
7
5
5
5
0.002
ADCMUTE
RECEN
LABEL
LABEL
MUTE
MUTE
Time(s)
0.003
DEFAULT
DEFAULT
0
0
0
0
0.004
ADC MUTE Left and Right
ADC Mute select
ADC Mute select
REC Output Enable
0 : Normal Operation
1: mute ADC left and ADC
right
0 : Normal Operation
1: mute ADC left
0 : Normal Operation
1: mute ADC right
0 : REC output muted
1: REC output enabled
DESCRIPTION
DESCRIPTION
PD Rev 4.2 March 2008
0.005
Production Data
0.006
MID
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