Production Data

WM9703

WOLFSON MICROELECTRONICS LTD

PD Rev 3.4 January 2001

23

RECORD SELECT CONTROL REGISTER (INDEX 1Ah)

Used to select the record source independently for right and left (see Table 13). The default value is

0000h, which corresponds to Mic in.

SR2 TO SR0

RIGHT RECORD SOURCE

SL2 TO SL0

LEFT RECORD SOURCE

0

Mic

0

Mic

1

CD in (R)

1

CD in (L)

2

Video in (R)

2

Video in (L)

3

Aux in (R)

3

Aux in (L)

4

Line in (R)

4

Line in (L)

5

Stereo mix (R)

5

Stereo mix (L)

6

Mono mix

6

Mono mix

7

Phone

7

Phone

Table 13 Record Select Register Function

RECORD GAIN REGISTERS (INDEX 1Ch AND 1Eh)

1Ch is for the stereo input and 1Eh is for the optional special purpose correlated audio Mic channel.

Each step corresponds to 1.5dB. 22.5dB corresponds to 0F0Fh and 000Fh respectively. The MSB of

the register is the mute bit. When this bit is set to 1, the level for that channel(s) is set at -

The default value is 8000h, which corresponds to 0dB gain with mute on.

MUTE

GX3...GX0

FUNCTION

0

1111

+22.5dB gain

0

0000

0dB gain

1

xxxxx

-

Table 14 Record Gain Register Function

GENERAL PURPOSE REGISTER (INDEX 20h)

This register is used to control several miscellaneous functions of the WM9703.

Below is a summary of each bit and its function. Only the 3D, MIX, MS and LPBK bits are supported

by the WM9703. The MS bit controls the Mic selector. The LPBK bit enables loopback of the ADC

output to the DAC input without involving the AC-link, allowing for full system performance

measurements. The function default value is 8000h which is all off.

BIT

FUNCTION

WM9703

SUPPORT

POP

PCM out path and mute, 0 = pre-3D, 1 = post-3D

Yes, but fixed at 1

ST

Simulated stereo enhancement, on/off 1 = on

No

3D

3D stereo enhancement on/off, 1 = on

Yes

LD

Loudness (bass boost) on/off, 1 = on

No

LLBK

Local loop back - for modem, line codec

No

RLBK

Remote loop back - for modem, line codec

No

MIX

Mono output select 0 = Mix, 1 = Mic

Yes

MS

Mic select 0 = Mic1, 1 = Mic2

Yes

LPBK

ADC/DAC/ loopback mode

Yes

Table 15 General Purpose Register Function

3D CONTROL REGISTER (INDEX 22h)

This register is used to control the centre and/or depth of the 3D stereo enhancement function built

into of the AC’97 component. Only the depth bits, DP0 to 3 have effect in the WM9703.

DP3…DP0

DEPTH

00%

1

-

8

Typical value

-

15

100%