Atmel SpW-10X Loop-back with Self-Addressing, Group adaptive routing when ports not ready

SpW-10X

SpaceWire Router

User Manual

Address 76 – Routing table entry

Header Deletion disabled

Port 4

Port 5

Port 6

Ref.: UoD_SpW-10X_

UserManual

Issue: 3.4

Date: 11th July 2008

1
76 1		4
2	R1	5
3		6

Group adaptive routing packet with address 76 arrives at port 1 Ports 4 and 5 are busy routing packet data from ports 2 and 3

2

1		4
2	R1	5
3		6
			76

Routing logic assigns ports 6 to packet at port 1

Figure 8-11 Group adaptive routing when other ports busy

8.3.3.3 Group adaptive routing when ports not ready

A similar arrangement to that of section 8.3.3.2 is shown in Figure 8-12. In this scenario, two of the output ports which address 76 can use are not ready for use (i.e. the links are not running). The packet is routed to output port 6 since it is running and not being used to route another packet.

Address 76 – Routing table entry

Header Deletion disabled

Port 4

Port 5

Port 6

1
76 1		4
2	R1	5
3		6

X X

2

1 4

2 R1 5

36

X

X

76

Group adaptive routing packet with address 76 arrives at port 1	Routing logic assigns ports 6 to packet at port 1
Ports 4 and 5 are not ready to accept packet data

Figure 8-12 Group adaptive routing when ports not ready

Note: if the Start on Request mode is enabled, the output ports in the group that are not ready will attempt to make a connection. The packet will be routed to the output port in the group that is ready first.

8.3.4 Loop-back with Self-Addressing

The Enable Self-Addressing bit in the router control register determines if the router is to support loop- back connections. Loop-back connections can be useful for debugging or ping operations where a packet is “bounced” of the router and returned to the source. If the Enable Self-Addressing bit is clear

Preliminary 93