WM9090
Production Data
w
PD, November 2010, Rev 4.1
22
REGISTER
ADDRESS
BIT LABEL
DEFAULT
DESCRIPTION
3:2
IN2A_SPKMIX_VOL
00
IN2A to SPKMIX volume control
00 = 0dB
01 = -6dB
10 = -9dB
11 = -12dB
1:0
IN2B_SPKMIX_VOL
[1:0]
00
IN2B to SPKMIX volume control
00 = 0dB
01 = -6dB
10 = -9dB
11 = -12dB
Table 5 Speaker Mixer (SPKMIX) Control
SPEAKER OUTPUT VOLUME CONTROL
The speaker output PGA controls are shown in Table 6.
A zero-cross function is provided on the speaker output PGA. Note that the timeout clock TOCLK
must be enabled when using the zero-cross function. See “Clocking Control” for more information on
the TOCLK control fields.
The SPKOUT_VU bit controls the loading of the speaker PGA volume data. This bit should be set to
1 whenever the SPKOUTL_VOL register is updated.
REGISTER
ADDRESS
BIT LABEL
DEFAULT
DESCRIPTION
R38 (26h)
Speaker
Volume Left
8
SPKOUT_VU
N/A
Speaker Output PGA Volume
Update
Writing a 1 to this bit will update the
SPKOUTL volume.
7
SPKOUTL_ZC
0
Speaker Output PGA Zero Cross
Control
0 = Change gain immediately
1 = Change gain on zero cross only
6
SPKOUTL_MUTE
0
Speaker Output PGA Mute
0 = Un-mute
1 = Mute
5:0
SPKOUTL_VOL [5:0]
39h
(0dB)
Speaker Output PGA Volume
-57dB to +6dB in 1dB steps
(See Table 11 for output PGA
volume control range)
Table 6 Speaker Output PGA Control
SPEAKER BOOST MIXER CONTROL
The Class D speaker driver also incorporates its own boost mixer.
The boost mixer provides an additional AC gain (boost) function to shift signal levels between the
AVDD and SPKVDD voltage domains for maximum output power. The AC gain (boost) function is
described in the “Analogue Outputs” section.
The SPKMIXL_TO_SPKOUTL register bit must be enabled when using the speaker output signal
path, as described in Table 7. Note that this is the default condition.
REGISTER
ADDRESS
BIT LABEL
DEFAULT
DESCRIPTION
R36 (24h)
SPKOUT
Mixers
4
SPKMIXL_TO_SPKOU
TL
1
SPKMIX to Speaker Output enable
0 = Disabled
1 = Enabled
Table 7 Speaker Boost Mixer Control
