WM5102 Datasheet, PDF (160/334 Pages) Wolfson Microelectronics plc – Audio Hub CODEC with Voice Processor DSP

WM5102
Production Data
OUTPUT SIGNAL PATH DIGITAL VOLUME CONTROL
A digital volume control is provided on each of the output signal paths, providing -64dB to +31.5dB
gain control in 0.5dB steps. An independent mute control is also provided for each output signal path.
Whenever the gain or mute setting is changed, the signal path gain is ramped up or down to the new
settings at a programmable rate. For increasing gain (or un-mute), the rate is controlled by the
OUT_VI_RAMP register. For decreasing gain (or mute), the rate is controlled by the OUT_VD_RAMP
register. Note that the OUT_VI_RAMP and OUT_VD_RAMP registers should not be changed while a
volume ramp is in progress.
The OUT_VU bits control the loading of the output signal path digital volume and mute controls. When
OUT_VU is set to 0, the digital volume and mute settings will be loaded into the respective control
register, but will not actually change the signal path gain. The digital volume and mute settings on all
of the output signal paths are updated when a 1 is written to OUT_VU. This makes it possible to
update the gain of multiple signal paths simultaneously.
For correct gain ramp behaviour, the OUT_VU bits should not be written during the 0.28ms after any
of the output path enable bits (see Table 59) have been asserted. It is recommended that the output
path mute bit be set when the respective output driver is enabled; the signal path can then be un-
muted after the 0.28ms has elapsed.
Note that, although the digital volume control registers provide 0.5dB steps, the internal circuits
provide signal gain adjustment in 0.125dB steps. This allows a very high degree of gain control, and
smooth volume ramping under all operating conditions.
The digital volume control register fields are described in Table 64 and Table 65.
REGISTER BIT
ADDRESS
LABEL
R1033
(0409h)
6:4 OUT_VD_RAMP
[2:0]
Output
Volume
Ramp
2:0 OUT_VI_RAMP
[2:0]
R1041
9
(0411h)
DAC
Digital
Volume 1L ₈
OUT_VU
OUT1L_MUTE
DEFAULT
DESCRIPTION
010
Output Volume Decreasing Ramp Rate
(seconds/6dB)
000 = 0ms
001 = 0.5ms
010 = 1ms
011 = 2ms
100 = 4ms
101 = 8ms
110 = 15ms
111 = 30ms
This register should not be changed while
a volume ramp is in progress.
010
Output Volume Increasing Ramp Rate
(seconds/6dB)
000 = 0ms
001 = 0.5ms
010 = 1ms
011 = 2ms
100 = 4ms
101 = 8ms
110 = 15ms
111 = 30ms
This register should not be changed while
a volume ramp is in progress.
Output Signal Paths Volume Update
Writing a 1 to this bit will cause the Output
Signal Paths Volume and Mute settings to
be updated simultaneously
1
Output Path 1 (Left) Digital Mute
0 = Un-mute
1 = Mute
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PD, June 2014, Rev 4.2
160