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MT90871
Data Sheet
8
Zarlink Semiconductor Inc.
1.0
Bidirectional and Unidirectional Applications
The MT90871 has a maximum capacity of 8,192 input channels and 8,192 output channels. This is calculated from
the maximum number of streams and channels: 32 input streams (16 Backplane, 16 Local) at 16.384Mb/s and 32
output streams (16 Backplane, 16 Local) at 16.384Mb/s.
One typical mode of operation is to separate the Backplane and Local sides, as shown in Figure 3 below.
Figure 3 - 4,096 x 4,096 Channels (16Mb/s), Bidirectional Switching
In this system setup, the chip has a capacity of 4,096 input channels and 4,096 output channels on the Backplane
side as well as 4,096 input channels and 4,096 output channels on the Local side. Note that some or all of the output
channels on one side can come from the other side, i.e. Backplane input to Local output switching.
Often a system design does not need to differentiate between Backplane and Local side, and merely needs
maximum switching capacity. In this case, the MT90871 can be used as shown in Figure 4 to give the full 8,192 x
8,192 channel capacity.
Figure 4 - 8,192 x 8,192 Channels (16Mb/s), Unidirectional Switching
In this system, the Backplane and Local inputs and outputs are combined and the switch appears as a 32 stream
input by 32 stream output switch. This style of operation is similar to older switch designs, such as the MT90826.
1.1
Flexible Configuration
The F8KDX can be configured as a 4K by 4K non-blocking bi-directional digital switch, an 8K by 8K unidirectional
non-blocking switch, and as a blocking switch with various switching capacities.
1.1.1
A. Blocking Bi-directional Configuration (Typical System Configuration)
4,096-channel x 4,096-channel non-blocking switching from backplane to local streams
4,096-channel x 4,096-channel non-blocking switching from local to backplane streams
4,096-channel x 4,096-channel non-blocking switching from backplane input to backplane output streams
4,096-channel x 4,096-channel non-blocking switching from local input to local output streams
MT90871
16 streams
16 streams
16 streams
16 streams
BSTi0-15
BSTo0-15
LSTo0-15
LSTi0-15
BACKPLANE
LOCAL
MT90871
16 streams
16 streams
16 streams
16 streams
BSTi0-15
LSTi0-15
BSTo0-15
LSTo0-15
INPUT
OUTPUT