WM8962 Datasheet, PDF (126/295 Pages) Wolfson Microelectronics plc – Ultra-Low Power Stereo CODEC with Audio Enhancement DSP, 1W Stereo Class D Speaker Drivers and Ground Referenced Headphone Drivers

126
WM8962
HEADPHONE MIXER CONTROL
The two headphone mixers - HPMIXL and HPMIXR – can each have any combination of the six
available input paths enabled as described in Table 78 (left headphone mixers) and Table 79 (right
headphone mixers). The six input signal paths are two from the DACs (DACL and DACR), two from
the input mixers (MIXINL and MIXINR) and two bypass paths direct from the IN4 input pins (IN4L and
IN4R). The headphone mixers are muted by default.
The two signal paths from the left and right DACs to each of the two headphone mixers HPMIXL and
HPMIXR are enabled using the register bits DACL_TO_HPMIXL, DACL_TO_HPMIXR,
DACR_TO_HPMIXL and DACR_TO_HPMIXR. There is no selectable gain associated with these
mixer paths.
The two DAC output signals can also be configured to bypass the headphone mixers using the
HPMIXL_TO_HPOUTL_PGA and HPMIXR_TO_HPOUTR_PGA register bits. Note that the DAC
output signals bypass the mixers by default.
The direct signal paths from each of the input mixers MIXINL and MIXINR to each of the headphone
mixers HPMIXL and HPMIXR are enabled using the MIXINL_TO_HPMIXL, MIXINL_TO_HPMIXR,
MIXINR_TO_HPMIXL and MIXINR_TO_HPMIXR register bits. A selectable -6dB control is available
on each of these paths to help avoid signal clipping.
The direct signal paths from the IN4L and IN4R input pins to the headphone mixers HPMIXL and
HPMIXR are enabled using the IN4L_TO_HPMIXL, IN4L_TO_HPMIXR, IN4R_TO_HPMIXL, and
IN4R_TO_HPMIXR register bits. Each input signal path from IN4 also has an associated PGA with a
gain range from -15dB to +6dB.
REGISTER
ADDRESS
R100 (64h)
Headphone
Mixer (1)
R102 (66h)
Headphone
Mixer (3)
BIT
LABEL
DEFAULT
DESCRIPTION
7 HPMIXL_TO_HP
0
OUTL_PGA
5 DACL_TO_HPMI
0
XL
4 DACR_TO_HPMI
0
XL
3 MIXINL_TO_HPM
0
IXL
2 MIXINR_TO_HP
0
MIXL
1 IN4L_TO_HPMIX
0
L
0 IN4R_TO_HPMIX
0
L
8 HPMIXL_MUTE
1
7 MIXINL_HPMIXL_
0
VOL
Left Headphone PGA Path Select
0 = DACL Output
1 = HPMIXL Output
Left DAC to Left Headphone Mixer
select
0 = Disabled
1 = Enabled
Right DAC to Left Headphone Mixer
select
0 = Disabled
1 = Enabled
Left Input Mixer to Left Headphone
Mixer select
0 = Disabled
1 = Enabled
Right Input Mixer to Left Headphone
Mixer select
0 = Disabled
1 = Enabled
Input IN4L to Left Headphone Mixer
select
0 = Disabled
1 = Enabled
Input IN4R to Left Headphone Mixer
select
0 = Disabled
1 = Enabled
Left Headphone Mixer Mute
0 = Unmuted
1 = Muted
Left Input Mixer to Left Headphone
Mixer volume
0 = 0dB
1 = -6dB
Rev 4.3