Production Data
WM8776
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 DIN is always an input to the WM8776 and DOUT is always an output.
The default is Slave mode.
In Slave mode (MS=0) ADCLRC, DACLRC, ADCBCLK and DACBCLK are inputs to the WM8776
(Figure 11). DIN and DACLRC are sampled by the WM8776 on the rising edge of DACBCLK,
ADCLRC is sampled on the rising edge of ADCBCLK. ADC data is output on DOUT and changes on
the falling edge of ADCBCLK. By setting control bit BCLKINV the polarity of ADCBCLK and
DACBCLK may be reversed so that DIN and DACLRC are sampled on the falling edge of DACBCLK,
ADCLRC is sampled on the falling edge of ADCBCLK and DOUT changes on the rising edge of
ADCBCLK.
DACBCLK
ADCBCLK
ADCLRC
DVD
Controller
WM8776
CODEC
DACLRC
DOUT
DIN
Figure 11 Slave Mode
In Master mode (MS=1) ADCLRC, DACLRC, ADCBCLK and DACBCLK are outputs from the
WM8776 (Figure 12). ADCLRC, DACLRC, ADCBCLK and DACBCLK are generated by the WM8776.
DIN is sampled by the WM8776 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 control bit BCLKINV, the polarity of ADCBCLK and
DACBCLK may be reversed so that DIN is sampled on the falling edge of DACBCLK and DOUT
changes on the rising edge of ADCBCLK.
DACBCLK
ADCBCLK
ADCLRC
DACLRC
DOUT
DVD
Controller
WM8776
CODEC
DIN
Figure 12 Master Mode
PD Rev 4.0 April 2005
19
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WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
