Motorola DSP56012 User Manual
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.
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
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.
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
Encoder
Preamble
Generator
ADO
DAX
State
Machine
Control
Signals
Signals
XNADBUF
Global Data Bus
0
23
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DAX
Clock
MUX
ACI
DSP
Core Clock
Core Clock
DAX
Clocks
XADSR
0
23
XADRA
0
23
XCTR
0
23
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MUX
MUX
MUX
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