ADAU1445 Analog Devices, ADAU1445 Datasheet - Page 47

• Manufacturer Part Number: ADAU1445
• Manufacturer: Analog Devices

Specifications of ADAU1445

• Instructions/cycles: 3584
• Digital I/o Channels: 24/24
• Analog I/o Channels: 0/0
• Product Description: Digital audio processor with flexible audio routing matrix, 8 × 2-channel ASRC

Routing Matrix Functionality
Serial Input Ports
The far left side of Figure 36 represents the audio input pins to
the ADAU1442/ADAU1445/ADAU1446, 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 by a number
of input channels that corresponds 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. C | Page 47 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; therefore, a port set to
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 in which
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
ADAU1442/ADAU1445/ADAU1446
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)