Datasheet

Audio Interface
1-16 ADSP-21489 EZ-Board Evaluation System Manual
192 KHz with all ADCs and DACs in TDM mode, the codec must run in
dual-line TDM mode.
For information on how to configure the multi-channel codec, refer to the
product datasheet at:
http://www.analog.com/en/audiovideo-prod-
ucts/audio-codecs/ad1939/products/product.html
.
The EZ-Board is connected to the AD1939 codec in master mode. The
internal PLL drives the ABCLK and ALRCLK clock signals out. Both clocks
are driven back to the codec’s DBCLK and DLRCLK pins via the R257 and R258
resistors. The ABCLK and ALRCLK clocks that are driven by the codec also
connect to the processor’s serial ports via the DAI pins. Resistors R262 and
R263 are used to feed the bit clock and frame sync signals of the processor’s
serial ports. Connecting the codec in this manner enables a flexible audio
sample rate and allows the processor to run at the maximum core
frequency.
The audio interface also has a 3.5 mm connector (J8) for headphones. The
headphones share the output with the external DAC5 and DAC6 circuits of
the analog audio interface. Switch SW23 must be enabled for the head-
phones. A volume control potentiometer (R493) is used to increase or
decrease the headphone’s volume. For more information, see “Headphone
Enable Switch (SW23)” on page 2-18.
Example programs are included in the EZ-Board installation directory to
demonstrate how to configure and use the board’s analog audio interface.
The DAI and DPI pins going to the AD1939 device can be disabled, then
used again on the expansion II interface. Refer to “DAI Interface” on
page 2-3 and “DPI Interface” on page 2-4 for more information about the
DAI and DPI switches.