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2 dax signals, Figure 8-1, Digital audio transmitter (dax) block diagram -4 – Motorola DSP56012 User Manual

Page 214: Dax signals -4, Are directly accessible by dsp instructions

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8-4

DSP56012 User’s Manual

MOTOROLA

Digital Audio Transmitter

DAX Signals

8.2

DAX SIGNALS

The DAX has two signal lines:

DAX Digital Audio Output (ADO)—The ADO pin sends audio and

non-audio data in the AES/EBU, CP340, and IEC958 formats in a biphase
mark format. ADO stays high when the DAX is disabled, and during
hardware reset and software reset.

DAX Clock Input (ACI)—When the DAX clock is configured to be supplied

externally, the external clock is applied to the ACI pin. The frequency of the
external clock must be 256 times, 384 times, or 512 times the audio sampling
frequency (256

×

Fs, 384

×

Fs, or 512

×

Fs). The ACI pin is high impedance

during hardware reset and software reset.

Note:

If the DAX is not used, connect the ACI pin to ground through an external
pull-down resistor to ensure a stable logic level at the input.

Figure 8-1 Digital Audio Transmitter (DAX) Block Diagram

XADRB

0

23

XADBUF

MUX

26

XSTR

C-U-V

PRTYG

Biphase
Encoder

Preamble

Generator

ADO

DAX

State

Machine

Control
Signals

XNADBUF

Global Data Bus

0

23

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DAX

Clock

MUX

ACI

DSP
Core Clock

DAX

Clocks

XADSR

0

23

XADRA

0

23

XCTR

0

23

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MUX

MUX

MUX

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