WM8971L Wolfson Microelectronics Ltd., WM8971L Datasheet - Page 21

• Manufacturer Part Number: WM8971L
• Description: Stereo Codec for Portable Audio Applications
• Manufacturer: Wolfson Microelectronics Ltd.

Production Data
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The inputs can also be muted in the analogue domain under software control. The software control
registers are shown in Table 7. If zero crossing is enabled, it is necessary to enable zero cross
timeout to un-mute the input PGAs. This is because their outputs will not cross zero when muted.
Alternatively, zero cross can be disabled before sending the un-mute command.
Table 7 Input PGA Software Control
R0 (00h)
Left Channel
PGA
R1 (01h)
Right Channel
PGA
R23 (17h)
Additional
Control (1)
REGISTER
ADDRESS
8
7
6
5:0
8
7
6
5:0
0
BIT
LIVU
LINMUTE
LZCEN
LINVOL
[5:0]
RIVU
RINMUTE
RZCEN
RINVOL
[5:0]
TOEN
LABEL
0
1
0
010111
( 0dB )
0
1
0
010111
( 0dB )
0
DEFAULT
Left Volume Update
0 = Store LINVOL in intermediate
latch (no gain change)
1 = Update left and right channel
gains (left = LINVOL, right =
intermediate latch)
Left Channel Input Analogue Mute
1 = Enable Mute
0 = Disable Mute
Note: LIVU must be set to un-mute.
Left Channel Zero Cross Detector
1 = Change gain on zero cross only
0 = Change gain immediately
Left Channel Input Volume Control
111111 = +30dB
111110 = +29.25dB
. . 0.75dB steps down to
000000 = -17.25dB
Right Volume Update
0 = Store RINVOL in intermediate
latch (no gain change)
1 = Update left and right channel
gains (right = RINVOL, left =
intermediate latch)
Right Channel Input Analogue Mute
1 = Enable Mute
0 = Disable Mute
Note: RIVU must be set to un-mute.
Right Channel Zero Cross Detector
1 = Change gain on zero cross only
0 = Change gain immediately
Right Channel Input Volume Control
111111 = +30dB
111110 = +29.25dB
. . 0.75dB steps down to
000000 = -17.25dB
Timeout Enable
0 : Timeout Disabled
1 : Timeout Enabled
DESCRIPTION
PD Rev 4.1 August 2005
WM8971L
21