WM8718

Production Data

w

PD Rev 4.1 March 2004

20

DIGITAL AUDIO INTERFACE CONTROL REGISTERS

The WM8718 has a fully featured PCM digital audio interface whose interface format is selected

via the FMT [1:0] and IWL[1:0] register bits in register M3.

REGISTER ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

0010

Format Control

1:0

IWL[1:0]

00

Interface format Select

0010

Format Control

3:2

FMT[1:0]

00

Interface format Select

Table 11 Interface Format Controls

FMT[1]

FMT[0]

IWL[1]

IWL[0]

AUDIO INTERFACE DESCRIPTION

(NOTE 1)

0

0

0

0

16 bit right justified mode

0

0

0

1

20 bit right justified mode

0

0

1

0

24 bit right justified mode

0

0

1

1

Not available

0

1

0

0

16 bit left justified mode

0

1

0

1

20 bit left justified mode

0

1

1

0

24 bit left justified mode

0

1

1

1

32 bit left justified mode

1

0

0

0

16 bit I

1

0

0

1

20 bit I

1

0

1

0

24 bit I

1

0

1

1

32 bit I

1

1

0

0

16 bit DSP mode

1

1

0

1

20 bit DSP mode

1

1

1

0

24 bit DSP mode

1

1

1

1

32 bit DSP mode

Table 12 Audio Data Input Format

Note:

1.

In all modes, the data is signed 2's complement. The digital filters always input 24-bit data. If

the DAC is programmed to receive 16 or 20 bit data, the WM8718 pads the unused LSBs

with ZEROS. If the DAC is programmed into 32-bit mode, the 8 LSBs are treated as zero.