wm8400 Wolfson Microelectronics plc, wm8400 Datasheet - Page 64

• Manufacturer Part Number: wm8400
• Description: Wolfson Audioplustm Hi-fi Audio Codec And Power Management Unit For Mobile Multimedia
• Manufacturer: Wolfson Microelectronics plc

WM8400
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INPUT MIXER ENABLE
The WM8400 has two analogue input mixers which allow the Input PGAs and Line Inputs to be
combined in a number of ways and output to the ADCs or to the Output Mixers via bypass paths.
The input mixers INMIXL and INMIXR are enabled by the AINL_ENA and AINR_ENA register bits, as
described in Table 25. These control bits also enable the Input Multiplexers and Differential Input
drivers, described in the following section.
Table 25 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, line inputs and the internal record path).
2. RXVOICE (a differential to single-ended conversion of LIN4/RXN and RIN4/RXP 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 26.
Table 26 Input Mixer Configuration
The Input Mixer configuration is described for each of the three modes in the following sections. Note
that the Left and Right multiplexer (mode) settings can be set independently.
R3 (03h)
R39 (27h)
REGISTER
REGISTER
ADDRESS
ADDRESS
9
8
3:2
1:0
BIT
BIT
AINL_ENA
(rw)
AINR_ENA
(rw)
AINLMODE
[1:0]
AINRMODE
[1:0]
LABEL
LABEL
0b
0b
00b
00b
DEFAULT
DEFAULT
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
(Enables AINRMUX, INMIXR, DIFFINR
and RXVOICE input to AINRMUX)
0 = Input Path disabled
1 = Input Path enabled
AINLMUX Input Source
00 = INMIXL (Left Input Mixer)
01 = RXVOICE (RXP - RXN)
10 = DIFFINL (LIN12 PGA - LIN34 PGA)
11 = (Reserved)
AINRMUX Input Source
00 = INMIXR (Right Input Mixer)
01 = RXVOICE (RXP - RXN)
10 = DIFFINR (RIN12 PGA - RIN34 PGA)
11 = (Reserved)
DESCRIPTION
DESCRIPTION
PP, April 2009, Rev 3.0
Pre-Production
64