Pre-Production
WM8959
In Differential Mode (AINLMODE=10, AINRMODE=10), no additional volume control is available in
the input signal path, but the Input PGA volume control can be used to adjust the signal level as with
other modes. Both PGAs on the desired channel(s) must be enabled, and the PGA volumes of each
set to the same value for true Differential input characteristics. The PGA Output (LIN12 or RIN12) to
Mixer (INMIXL or INMIXR) path must also be enabled on the desired channel(s) by use of register bit
L12MNB or R12MNB. This configuration is illustrated in Figure 26. The applicable register settings
are shown in Table 11.
CONFIGURATION
REGISTER SETTINGS
Left Channel Differential
Mode
1. Select Differential Mode
AINLMODE = 10
2. Enable LIN12 input path
L12MNB = 1
(DIFFINL to AINLMUX)
3. Set channel volume as required.
LIN12VOL, LIN12MUTE
LIN34VOL, LIN34MUTE
Important: The LIN12 and LIN34
volume and mute settings must be
set to the same value. See Table 5
for full definitions of these fields.
Right Channel Differential
Mode
1. Select Differential Mode
AINRMODE = 10
2. Enable RIN12 input path
3. Set channel volume as required.
R12MNB = 1
(DIFFINR to AINRMUX)
RIN12VOL, RIN12MUTE
RIN34VOL, RIN34MUTE
Important: The RIN12 and RIN34
volume and mute settings must be
set to the same value. See Table 5
for full definitions of these fields.
Table 11 Differential Mode Register Settings
Figure 26 Differential Mode Signal Paths
PP, May 2008, Rev 3.1
47
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
