WM8522
Production Data
In hardware mode (MODE pin set high) the MUTE pin becomes a bi-directional pin. Therefore if it is
driven low the device will never softmute. If it is driven high then all channels will softmute
immediately.
However if the pin is connected to a high impedance, or left floating, then when all three internal zero
flags are raised the WM8522 will also drive a weak logic high signal on the MUTE pin (output
impedance 10kOhms) which can be used to drive an external device.
It is not possible to perform analogue mute in Hardware mode.
CH1 ZFLAG
CH2 ZFLAG
CH3 ZFLAG
Channel1
Softmute
(Internal Signals)
10k
Ω
MUTE
(pin)
Channel2
Softmute
Channel3
Softmute
Figure 10 MUTE Logic in Hardware Mode
INPUT FORMAT SELECTION
In hardware mode, CSB/I2S and SCLK/IWL become input controls for selection of input data format
type and input data word length for the DAC.
CSB/I2S
SCLK/IWL
INPUT DATA MODE
24-bit right justified
0
0
1
0
1
0
20-bit right justified
16-bit I2S
24-bit I2S
1
1
Table 8 Input Format Selection
Note:
In 24 bit I2S mode, any width of 24 bits or less is supported provided that the left/right clocks
(LRCLK) are high for a minimum of 24 bit clocks (BCLK) and low for a minimum of 24 bit clocks. If
exactly 32 bit clocks occur in one left/right clock (16 high, 16 low) the chip will auto detect and run a
16 bit data mode.
DE-EMPHASIS CONTROL
In hardware mode, the SDIN/DM pin becomes an input control for selection of de-emphasis filtering
to be applied.
SDIN/DM
DE-EMPHASIS
0
Off
On
1
Table 9 De-emphasis Control
PD Rev 4.0 July 2006
14
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