wm8569seds-v Wolfson Microelectronics plc, wm8569seds-v Datasheet - Page 16

• Manufacturer Part Number: wm8569seds-v
• Description: 24-bit, 192khz Stereo Codec With Volume Control
• Manufacturer: Wolfson Microelectronics plc

WM8569
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The MUTE pin is an input to select mute or not mute. MUTE is active high; taking the pin high
causes the filters to soft mute, ramping down the audio signal over a few milliseconds. Taking MUTE
low again allows data into the filter.
The automute function detects a series of ZERO value audio samples of 1024 samples long being
applied to both channels. After such an event, a latch is set whose output (AUTOMUTED) is wire
OR’d through a 10kΩ resistor to the MUTE pin. Thus if the MUTE pin is not being driven, the
automute function will assert mute.
If MUTE is tied low, AUTOMUTED is overridden and will not mute unless the IZD register bit is set. If
MUTE is driven from a bi-directional source, then both MUTE and automute functions are available. If
MUTE is not driven, AUTOMUTED appears as a weak output (10kΩ source impedance) and can be
used to drive external mute circuits. AUTOMUTED will be removed as soon as any channel receives
a non-ZERO input.
A diagram showing how the various Mute modes interact is shown below.
Figure 10 Control of MUTE Modes
INPUT FORMAT SELECTION
In hardware mode, CSB/IDF and SCLK/IWL become input controls for selection of input data format
type and input data word length for both the ADC and DAC.
Table 8 Input Format Selection
Note:
In 24 bit I
(ADCLRC and DACLRC) are high for a minimum of 24 bit clocks (ADCBCLK and DACBCLK) and
low for a minimum of 24 bit clocks.
DE-EMPHASIS CONTROL
In hardware mode, the SDIN/DM pin becomes an input control for selection of de-emphasis filtering
to be applied.
Table 9 De-emphasis Control
MUTE (Register Bit)
IZD (Register Bit)
(Internal Signal)
2
S mode, any width of 24 bits or less is supported provided that the left/right clocks
SDIN/DM
CSB/IDF
AUTOMUTED
0
0
1
1
0
1
MUTE
PIN
10k
DE-EMPHASIS
SCLK/IWL
Off
On
0
1
0
1
24-bit right justified
20-bit right justified
16-bit I
24-bit I
INPUT DATA MODE
2
2
S
S
PD Rev 4.0 June 2006
SOFTMUTE
(Internal
Signal)
Production Data
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