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Spw-10x spacewire router, User manual, Preliminary – Atmel SpaceWire Router SpW-10X User Manual

Page 18: 4 expanding the number of router ports

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Ref.: UoD_SpW-10X_

UserManual

Issue: 3.4

SpW-10X

SpaceWire Router

User Manual

Date: 11

th

July 2008

Preliminary

18

Instrument

1

Instrument

2

Instrument

3

Instrument

4

Memory

Unit

Processor

SpW‐10X

Router

Instrument

5

Instrument

6

SpaceWire Node with Embedded Router

SpaceWire Links

Figure 2-3 Embedded Router

In Figure 2-3 a SpaceWire system similar to that shown in Figure 2-1 is shown with the SpW-10X
router embedded in a SpaceWire node along with a processor. The processor interfaces can interface
to the SpW-10X router using the external FIFO ports saving some SpaceWire ports for connecting to
additional instruments. For redundancy a pair of the SpaceWire nodes with embedded routers may be
used.

2.4 EXPANDING THE NUMBER OF ROUTER PORTS

If a routing switch with a larger number of SpaceWire (or external) ports is required then this can be
accomplished by joining together two or more routers using some of the SpaceWire links. For example
using two SpaceWire links to join together two router devices would create an effective router with
twelve SpaceWire ports and four external ports. Note, however, that an extra path addressing byte is
needed to route packets between the two routers and that there is additional routing delay.