WM8569

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PP Rev 1.1 December 2005

16

DIGITAL AUDIO INTERFACE

MASTER AND SLAVE MODES

The audio interface operates in either Slave or Master mode, selectable using the DACMS and

ADCMS control bits. In both Master and Slave modes DIN is always an input to the WM8569 and

DOUT is always an output. The default is Slave mode.

In Slave mode, DACLRC, ADCLRC, DACBCLK and ADCBCLK are inputs to the WM8569 (Figure 9).

DIN and DACLRC are sampled by the WM8569 on the rising edge of DACBCLK. ADC data is output

on DOUT and changes on the falling edge of ADCBCLK.

By setting the control bit DACBCP the polarity of DACBCLK may be reversed so that DIN is sampled

on the falling edge of DACBCLK. By setting the control bit ADCBCP, the polarity of ADCBCLK may

be reversed so that DOUT changes on the rising edge of ADCBCLK.

Figure 9 Slave Mode

In Master mode, DACLRC, ADCLRC, DACBCLK and ADCBCLK are outputs from the WM8569

(Figure 10). DACLRC, ADCLRC, DACBCLK and ADCBCLK are generated by the WM8569. DIN is

sampled by the WM8569 on the rising edge of DACBCLK so the controller must output DAC data

that changes on the falling edge of DACBCLK. ADC data is output on DOUT and changes on the

falling edge of ADCBCLK.

By setting the control bit DACBCP the polarity of DACBCLK may be reversed so that DIN is sampled

on the falling edge of DACBCLK. By setting the control bit ADCBCP, the polarity of ADCBCLK may

be reversed so that DOUT changes on the rising edge of ADCBCLK.

Figure 10 Master Mode