Production Data

WM8569

w

PD Rev 4.0 June 2006

27

ADC DIGITAL AUDIO INTERFACE CONTROL REGISTER

Interface format is selected via the ADCFMT[1:0] register bits:

REGISTER ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

0001011

Interface Control

1:0

ADCFMT[1:0]

00

Interface Format Select

00: Right justified mode

01: Left justified mode

10: I

11: DSP mode A or B

The ADCIWL[1:0] bits are used to control the input word length.

REGISTER ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

0001011

Interface Control

3:2

ADCIWL[1:0]

00

Input Word Length

00: 16 bit data

01: 20 bit data

10: 24 bit data

11: 32 bit data

Note: 32-bit right justified mode is not supported.

In all modes, the data is signed 2's complement.

ADC MASTER MODE SELECT

Control bit ADCMS selects between audio interface Master and Slave Modes. In Master mode

ADCLRC and ADCBCLK are outputs and are generated by the WM8569. In Slave mode ADCLRC

and ADCBCLK are inputs to WM8569.

REGISTER ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

0001011

Interface Control

4

ADCMS

0

ADC Audio Interface

Master/Slave Mode Select:

0: Slave mode

1: Master mode

MASTER MODE ADCLRC FREQUENCY SELECT

In Master mode the WM8569 generates ADCLRC and ADCBCLK. These clocks are derived from the

master clock and the ratio of ADCMCLK to ADCLRC is set by ADCRATE.

REGISTER ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

0001011

ADCLRC and ADCBCLK

Frequency Select

7:5

ADCRATE [2:0]

010

Master Mode

ADCMCLK:ADCLRC Ratio

Select:

010: 256fs

011: 384fs

100: 512fs

101: 768fs

ADC OVERSAMPLING RATE SELECT

For ADC operation at 96kHz it is recommended that the user set the ADCOSR bit. This changes the

ADC signal processing oversampling rate to 64fs. The 64fs oversampling rate is only available in

modes were a 96KHz rate is supported, i.e. 256fs or 384fs. In all other modes the ADC will stay in a

128fs oversampling rate irrespective of what this bit is set to.

REGISTER ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

0001011

ADC Oversampling Rate

8

ADCOSR

0

ADC Oversampling Rate Select:

0: 128x oversampling

1: 64x oversampling