adau1442 Analog Devices, Inc., adau1442 Datasheet - Page 50

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

Flexible Audio Routing Matrix—Output Side
Much like the input side, the output side of the flexible audio
routing matrix takes several stereo pairs, which can be
asynchronous, and connects them to the 12 stereo pairs that
will be output from the chip on the serial output ports. The
connections must again be one-to-one, meaning that from the
20 possible stereo pairs entering the FARM output side, only 12
can be selected to output from the chip. This process is
represented in Figure 47 as a large gray box.
The outputs from the ASRCs are automatically connected to
both the DSP and to the FARM output side.
Note that on the output side, unlike on the input side, the DSP
outputs are not hardwired to the output channels.
FROM ASRCs
FROM DSP
Figure 47. Flexible Audio Routing Matrix—Output Side
10, 11
12, 13
14, 15
0, 1
2, 3
6, 7
8, 9
4, 5
TO DSP
10, 11
12, 13
14, 15
16, 17
18, 19
20, 21
22, 23
0, 1
2, 3
4, 5
6, 7
8, 9
10, 11
12, 13
14, 15
16, 17
18, 19
20, 21
22, 23
0, 1
2, 3
4, 5
6, 7
8, 9
CHANNELS
OUTPUT
(24 CH)
Rev. PrA | Page 50 of 92
Automatic Output Channel Assignment
From the 24 output channels, there are nine serial output ports
available to output the data. By selecting different output modes,
the user can output the data in the desired format. Once the modes
are selected for each serial output port, the output channels are
automatically assigned to sequentially corresponding serial output
ports according to the number of channels desired in the stream.
For clarification, see Figure 48.
In this example, 14 output channels need to be output on three
serial output ports. To accomplish this, serial output modes must
be chosen to fit the desired system. In this case, SDATA_OUT0
is set to TDM8 mode, SDATA_OUT1 is set to I
SDATA_OUT2 is set to TDM4 mode. Using this information,
the automatic output channel assignment algorithm routes
Output Channels[7:0] to SDATA_OUT0, Output Channels[9:8]
to SDATA_OUT1, and Output Channels[13:10] to SDATA_OUT2.
Note that output channels must be assigned sequentially, and no
pair can be skipped. If an output channel is left empty (no data
routed to it from the ASRCs or DSP), it is still assigned to a
serial output port.
2
S mode, and