adau1442 Analog Devices, Inc., adau1442 Datasheet - Page 46

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

Routing Matrix Functionality
Serial Input Ports
The far left side of Figure 36 represents the audio input pins to
the ADAU144x, namely SDATA_IN0 to SDATA_IN8 and
SPDIFI. The serial audio data signals can be represented in any
standard mode, including time division multiplexing (TDM)
modes, as detailed in the Serial Data Input/Output section.
After passing through the serial input ports, the signals undergo
an automatic input channel assignment procedure.
Automatic Input Channel Assignment
The serial input ports can handle up to nine input signals. A
standard data format is I
both the left and right channels of a stereo pair. However, some
of the signals input to the serial input ports may contain data, in
TDM format, for more than two channels. The input to the
FARM allows for 24 channels, or 12 stereo pairs. Therefore, a
method is required to decompose nine signals (containing two
or more channels) into 12 stereo audio channel pairs. This is
accomplished by the automatic input channel assignment block.
In sequential order, each input signal is appropriated a number
of input channels corresponding to its channel content.
In the example shown in Figure 37, there are four input signals
to the serial input ports: SDATA_IN0 (I
SDATA_IN2 (TDM4), and SDATA_IN3 (I
containing two channels (I
Input Channel 1. SDATA_IN1, containing eight channels (TDM8),
SDATA_IN1 (TDM8)
SDATA_IN2 (TDM4)
SDATA_IN0 (I
SDATA_IN3 (I
Figure 37. Automatic Input Channel Assignment Example
2
2
S)
S)
SERIAL
MODES
SERIAL
PORTS
INPUT
INPUT
(×9)
2
S (inter-IC sound), which contains
2
S), is routed to Input Channel 0 and
CHANNELS
(24 CH)
INPUT
2
S), SDATA_IN1 (TDM8),
10, 11
12, 13
14, 15
16, 17
18, 19
20, 21
22, 23
0, 1
2, 3
4, 5
6, 7
8, 9
2
S). SDATA_IN0,
SDATA_IN0 (I
SDATA_IN1 (TDM8)
SDATA_IN1 (TDM8)
SDATA_IN1 (TDM8)
SDATA_IN1 (TDM8)
SDATA_IN2 (TDM4)
SDATA_IN2 (TDM4)
SDATA_IN3 (I
2
2
S)
S)
Rev. PrA | Page 46 of 92
is routed sequentially to the 2, 3, 4, 5, 6, 7, 8, and 9 input channels.
SDATA_IN2, containing two stereo pairs (TDM4), is routed
sequentially to the 10, 11, 12, and 13 input channels. Finally,
SDATA_IN3, containing two channels (I
Channel 14 and Input Channel 15.
In this way, the input channels are filled automatically according to
the inputs and modes seen on the serial input ports.
When a pin is skipped, it is assigned to input channels
regardless, so care must be taken to select the proper input
channels within the DSP. Automatic channel assignment is
entirely based on the mode settings for a particular serial port,
so a port set in a 2-channel mode is assigned to two sequential
input channels, and a port set to a 4-channel mode is assigned
to four sequential input channels, and so on. Figure 38 shows an
example where several pins are disconnected in hardware and
the corresponding empty input channels are automatically
assigned.
Figure 38. Automatic Input Channel Assignment Example with Skipped Pins
SDATA_IN1 (TDM8)
NOTES
1. THE BLACK DASHED LINES REPRESENT DISCONNECTED PINS;
INPUT CHANNELS ARE ASSIGNED AUTOMATICALLY.
SDATA_IN3 (I
(NO DATA) (I
(NO DATA) (I
2
2
2
S)
S)
S)
SERIAL
MODES
SERIAL
PORTS
INPUT
INPUT
(×9)
CHANNELS
(24 CH)
INPUT
10, 11
12, 13
14, 15
16, 17
18, 19
20, 21
22, 23
0, 1
2, 3
4, 5
6, 7
8, 9
2
S), is routed to Input
(NO DATA)
SDATA_IN1 (TDM8)
SDATA_IN1 (TDM8)
SDATA_IN1 (TDM8)
SDATA_IN1 (TDM8)
(NO DATA)
SDATA_IN3 (I
2
S)