WM8766
Production Data
DAC OUTPUT PHASE
The DAC phase control word determines whether the output of each DAC is non-inverted or inverted
REGISTER ADDRESS
0000011
BIT
LABEL
PHASE
[2:0]
DEFAULT
DESCRIPTION
8:6
000
Bit
0
DAC
Phase
DAC Phase
DAC1L/R 1 = invert
DAC2L/R 1 = invert
1
2
DAC3L/R 1 = invert
DIGITAL ZERO CROSS-DETECT
The digital volume control also incorporates a zero cross detect circuit which detects a transition
through the zero point before updating the digital volume control with the new volume. This is
enabled by control bit DZCEN.
REGISTER ADDRESS BIT
LABEL
DEFAULT
DESCRIPTION
0001001
0
ZCD
0
DAC Digital Volume Zero Cross
Enable:
DAC Control
0: Zero cross detect enabled
1: Zero cross detect disabled
SOFTMUTE
The digital muting function used in Software and Hardware mode applies a softmute with the
operating characteristics shown in Figure 19.
1.5
1
0.5
0
-0.5
-1
-1.5
-2
-2.5
0
0.001
0.002
0.003
0.004
0.005
0.006
Time(s)
Figure 19 Soft Mute Operation
When the softmute is applied the output of the device will decay towards VMID with a time constant of
approximately 64 input samples. When the mute is released, either manually or automatically by the
chip, the output will restart immediately from the current input sample.
ANALOGUE MUTE
Analogue mute can only be used in software mode and will cause the output of the selected DAC to
perform an analogue mute that clamps the output of the DAC to VMID. This function is dependent in
the IZD bit which is described in section INFINITE ZERO DETECT, later.
PD Rev 4.1 July 2005
22
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
