WM8959
Pre-Production
INPUT MIXER ENABLE
The WM8959 has two analogue input mixers which allow the Input PGAs and Line Inputs to be
combined in a number of ways and fed to the Output Mixers.
The input mixers INMIXL and INMIXR are enabled by the AINL_ENA and AINR_ENA register bits, as
described in Table 7. These control bits also enable the Input Multiplexers and Differential Input
drivers, described in the following section.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R2 (02h)
9
AINL_ENA
(rw)
0b
Left Input Path Enable
(Enables AINLMUX, INMIXL, DIFFINL and
RXVOICE input to AINLMUX)
0 = Input Path disabled
1 = Input Path enabled
Right Input Path Enable
8
AINR_ENA
(rw)
0b
(Enables AINRMUX, INMIXR, DIFFINR
and RXVOICE input to AINRMUX)
0 = Input Path disabled
1 = Input Path enabled
Table 7 Input Mixer Enable
INPUT MIXER CONFIGURATION
The left and right channel input multiplexers AINLMUX and AINRMUX select one of three input
sources for the Left and Right channels independently. The three input sources are as follows:
1. INMIXL or INMIXR output (a combination of Input PGAs and line inputs).
2. RXVOICE (a differential to single-ended conversion of RXP and RXN inputs).
3. DIFFINL or DIFFINR output (a differential to single-ended conversion of two Input PGAs).
The input source for the multiplexers is controlled by register bits AINLMODE and AINRMODE as
described in Table 8.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R39 (27h)
3:2
AINLMODE
[1:0]
00b
AINLMUX Input Source
00 = INMIXL (Left Input Mixer)
01 = RXVOICE (RXP - RXN)
10 = DIFFINL (LIN12 PGA - LIN34 PGA)
11 = (Reserved)
1:0
AINRMODE
[1:0]
00b
AINRMUX Input Source
00 = INMIXR (Right Input Mixer)
01 = RXVOICE (RXP - RXN)
10 = DIFFINR (RIN12 PGA - RIN34 PGA)
11 = (Reserved)
Table 8 Input Mixer Configuration
PP, May 2008, Rev 3.1
44
w
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
