Datasheet

ADSP-21489 EZ-Board Evaluation System Manual 1-15

Using ADSP-21489 EZ-Board

Audio Interface

The AD1939 device is a high-performance, single-chip codec featuring

eight digital-to-analog converters (DACs) for audio output and four ana-

log-to-digital converters (ADCs) for audio input. This translates to four

stereo channels of audio out and two stereo channels of audio in.

The codec can input and output data at a sample rate of up to 192 kHz on

all channels.

The analog audio channels are available via single-ended RCA connectors

(J4 and J5) or differential DB25 connectors (P8 and P9). By default, the

EZ-Board is shipped with the RCA connectors used by the AD1939 codec

for audio in and out. To use the differential connectors, change DIP

switches SW15–18. A standard, off the shelf DB25 connector to XLR cables

is required to operate in this mode.

For more information, see “Audio In1 Left Selection Switch (SW15)” on

page 2-14 through “Audio In2 Left Selection Switch (SW18)” on

page 2-16, and “ADSP-21489 EZ-Board Schematic” on page B-1.

The processor interfaces with the codec via DAI and DPI pins. The DAI

pins can be configured to transfer serial data from the codec in Time-Divi-

sion Multiplexing (TDM) or Integrated Interchip Sound (I

S) mode. See

“DAI Interface” on page 2-3 for more information about the AD1939

connection to the DAI. The DPI interface pins can be configured to use

the SPI interface of the processor to set up the codec’s control registers.

See “DPI Interface” on page 2-4 for more information about the AD1939

connection to the DPI.

The master input clock (MCLK) of the codec is generated by the on-board

12.288 MHz oscillator. The internal PLL of the codec is used to generate

varying sample rates. The codec can be set up for 48 KHz, 96 KHz, or

192 KHz frequencies. The codec can run at these frequencies in both

TDM and I

S modes with all ADCs inputs and DACs outputs. To run