WM8768

Production Data

w

PD Rev 4.1 March 2005

16

DIGITAL AUDIO INTERFACE

MASTER AND SLAVE MODES

The audio interface operates in either Slave or Master mode, selectable using the MS control bit. In

both Master and Slave modes DIN1/2/3/4 are always inputs to the WM8768. The default is Slave

mode.

In Slave mode, LRCLK and BCLK are inputs to the WM8768 (Figure 11). DIN1/2/3/4 and LRCLK are

sampled by the WM8768 on the rising edge of BCLK.

By setting the control bit BCP the polarity of BCLK may be reversed so that DIN1/2/3/4 and LRCLK

are sampled on the falling edge of BCLK .

BCLK

DIN1/2/3/4

LRCLK

WM8768

DAC

DSP/

DECODER

4

Figure 11 Slave Mode

In Master mode, LRCLK and BCLK are outputs from the WM8768 (Figure 12). LRCLK and BCLK are

generated by the WM8768. DIN1/2/3/4 are sampled by the WM8768 on the rising edge of BCLK so

the controller must output DAC data that changes on the falling edge of BCLK.

By setting control bit BCP the polarity of BCLK may be reversed so that DIN1/2/3/4 are sampled on

the falling edge of BCLK..

BCLK

DIN1/2/3/4

LRCLK

WM8768

DAC

DSP/

DECODER

4

Figure 12 Master Mode