adau1442 Analog Devices, Inc., adau1442 Datasheet - Page 48

• Manufacturer Part Number: adau1442
• Description: Sigmadsp Digital Audio Processor With Flexible Audio Routing Matrix
• Manufacturer: Analog Devices, Inc.

Stereo ASRC Routing Overview
Within the ADAU1442 and ADAU1445, signals are required to
be synchronous to the master clock only when they are within
the DSP core itself. At all other times, signals can be asynchronous
to one another and the core. This is illustrated in Figure 42.
Because the ADAU1446 has no ASRCs, all audio signals must
be synchronous at all times.
The stereo ASRCs allow asynchronous signals to be converted
for processing in the DSP.
The input to an ASRC can come from one of 21 sources: the
12 input channel pairs, the S/PDIF Rx pair, or the eight DSP-to-
ASRC pairs. This allows the ASRCs to be placed both before
and after the DSP. Figure 43 and Figure 44 show examples of
how the ASRCs can be used both before and after the DSP.
ASYNCHRONOUS
Figure 42. Synchronous and Asynchronous Zones of the ADAU1442 and ADAU1445
Rev. PrA | Page 48 of 92
SYNCHRONOUS
FROM SERIAL
INPUT PORTS
S/PDIF Rx
FROM
10, 11
12, 13
14, 15
16, 17
18, 19
20, 21
22, 23
0, 1
2, 3
4, 5
6, 7
8, 9
FARM
FROM DSP
Figure 41. Stereo ASRC Routing
10, 11
12, 13
14, 15
0, 1
2, 3
4, 5
6, 7
8, 9
(8 × 2 CH)
STEREO
ASYNCHRONOUS
ASRCs
0, 1
2, 3
4, 5
6, 7
8, 9
10, 11
12, 13
14, 15
TO DSP
8
RATE
TO FARM
(OUTPUT SIDE)