WM8991 datasheet(48/174 Pages) WOLFSON

48 / 174 page

WM8991

Pre-Production

PP, May 2008, Rev 3.1

INPUT MIXER ENABLE

The WM8991 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 7. These control bits also enable the Input Multiplexers and Differential Input

drivers, described in the following section.

ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

AINL_ENA

(rw)

Left Input Path Enable

(Enables AINLMUX, INMIXL, DIFFINL and

RXVOICE input to AINLMUX)

0 = Input Path disabled

1 = Input Path enabled

R2 (02h)

AINR_ENA

(rw)

Right Input Path Enable

(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, line inputs and the internal record path).

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.

ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

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)

R39 (27h)

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

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.

WM8991 Datasheet(PDF) 48 Page - Wolfson Microelectronics plc

WM8991 Datasheet(HTML) 48 Page - Wolfson Microelectronics plc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL