WM9090 Datasheet, PDF (24/81 Pages) Wolfson Microelectronics plc – Ultra Low Power Audio Subsystem

WM9090
Production Data
REGISTER
ADDRESS
BIT
LABEL
7:6 IN1A_MIXOUTR_VOL
[1:0]
5:4 IN1B_MIXOUTR_VOL
[1:0]
3:2 IN2A_MIXOUTR_VOL
[1:0]
1:0 IN2B_MIXOUTR_VOL
[1:0]
Table 9 Right Output Mixer (MIXOUTR) Control
DEFAULT
00
00
00
00
DESCRIPTION
IN1A to MIXOUTR volume control
00 = 0dB
01 = -6dB
10 = -9dB
11 = -12dB
IN1B to MIXOUTR volume control
00 = 0dB
01 = -6dB
10 = -9dB
11 = -12dB
IN2A to MIXOUTR volume control
00 = 0dB
01 = -6dB
10 = -9dB
11 = -12dB
IN2B to MIXOUTR volume control
00 = 0dB
01 = -6dB
10 = -9dB
11 = -12dB
HEADPHONE OUTPUT VOLUME CONTROL
The headphone output PGA controls are shown in Table 10.
The HPOUT1_VU bits control the loading of the headphone PGA volume data. When HPOUT1_VU
is set to 0, the volume control data will be loaded into the respective control register, but will not
actually change the gain setting. The headphone PGA volume settings are both updated when a 1 is
written to either HPOUT1_VU bit. This makes it possible to update the gain of the left and right
output paths simultaneously.
A zero-cross function is provided on the headphone output PGAs. 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.
When the zero-cross function is enabled (using HPOUT1L_ZC or HPOUT1R_ZC), it will only become
effective after the respective PGA gain (or mute) has been changed in two or more subsequent
register writes.
To guarantee zero cross functionality, it is recommended to enable zero cross and toggle the
respective mute (HPOUT1L_MUTE or HPOUT1R_MUTE) before enabling the headphone output.
Alternatively, the zero-cross function can be ensured by updating the PGA gain register
(HPOUT1L_VOL or HPOUT1R_VOL) in two successive register writes - decrementing then
incrementing the setting by 1 gain step – after the zero-cross enable bits have been set.
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PD, November 2010, Rev 4.1
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