wm8987 Wolfson Microelectronics plc, wm8987 Datasheet - Page 34

• Manufacturer Part Number: wm8987
• Description: Stereo Codec For Portable Audio Applications
• Manufacturer: Wolfson Microelectronics plc

WM8987L
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Table 26 LOUT2/ROUT2 Volume Control
For single-ended operation, the LO2VU and RO2VU bits provide a method to ensure that the left and
right channel gains are updated at the same time (irrespective of the time delay between writing to
registers R40 and R41).
OUT3 OUTPUT
The OUT3 pin can drive a 16Ω or 32Ω headphone or be used as a DC reference for a capless
headphone output (see page 56). OUT3SW selects the mode of operation required.
Table 27 OUT3 Select
When OUT3SW=1, OUT3 drives out the inverted signal from the mono mixer. In this case, the mono
mixer should be enabled (MONO=1 in R26). The signal amplitude at the OUT3 output can be
adjusted under software control by writing to MONOVOL in R42.
Table 28 Mono Mixer Volume Control
R41 (29h)
ROUT2
Volume
R24 (18h)
Additional
Control (2)
R24 (18h)
Additional
Control (2)
R42 (2Ah)
Mono mixer
Volume
REGISTER
ADDRESS
REGISTER
REGISTER
ADDRESS
ADDRESS
BIT
8
6:0
7
8
4
6:0
7
BIT
BIT
OUT3SW
LABEL
ROUT2VOL
[6:0]
RO2ZC
RO2VU
ROUT2INV
MONOVOL
[6:0]
MOZC
LABEL
LABEL
DEFAULT
0
1111001
(0dB)
0
0
0
1111001
(0dB)
0
DEFAULT
DEFAULT
OUT3 select
0 : VREF
1 : mono mixer (volume controlled by MONOVOL)
ROUT2 volume
1111111 = +6dB
… (80 steps)
0110000 = -67dB
0101111 to 0000000 = Analogue MUTE
Left zero cross enable
1 = Change gain on zero cross only
0 = Change gain immediately
ROUT2 Volume Update
0 = Store ROUT2VOL in intermediate
1 = Update gain for both channels
(right=ROUT2VOL, left=from
intermediate latch)
ROUT2 Invert
0 = No Inversion (0° phase shift)
1 = Signal inverted (180° phase shift)
Mono Mixer Volume
1111111 = +6dB
… (80 steps)
0110000 = -67dB
0101111 to 0000000 = Analogue MUTE
Mono Mixer zero cross enable
1 = Change gain on zero cross only
0 = Change gain immediately
latch (no gain change)
DESCRIPTION
DESCRIPTION
DESCRIPTION
PD Rev 4.0 August 2008
Production Data
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