Atmel SpW-10X Expanding The Number Of Router Ports, SpaceWire Router, User Manual, Preliminary

SpW-10X	Ref.:	UoD_SpW-10X_
SpaceWire Router		UserManual
	Issue:	3.4
User Manual
	Date:	11th July 2008

SpaceWire Links

Instrument

1

Instrument

2

Instrument

3

Instrument

4

Instrument

5

Instrument

6

SpW‐10X

RouterProcessor

SpaceWire Node with Embedded Router

Memory

Unit

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.

Preliminary 18