Atmel SpW-10X user manual SpaceWire Router, User Manual, Preliminary

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

		1		4
		2	R1	5
4	4
		3		6
5	4

(a)

14

2 R2 5

36

Figure 8-25 Source Node Stalled: Watchdog Mode (a)

b)The packet from routing switch R1 port 3 is routed towards its destination but during packet transfer the source node stalls and does not supply any more data or the end of packet.

14

4 4 2 R1 5

36

14

2 R2 5

36

(b)

Figure 8-26 Source Node Stalled: Watchdog Mode (b)

c)The packet is blocked and the packet waiting at routing switch R1 port 2 cannot be routed. The watchdog timers in routing switches R1 and R2 detect the packet has become blocked and spills data from the input port and appends an error end of packet to the output port. This causes the network path from routing switch R1 port 4 to routing switch R2 port 1 to be cleared and the next packet can be routed.

		1		4
		2	R1	5
4	4
		3		6

(c)

14

2 R2 5

36

Figure 8-27 Source Node Stalled: Watchdog Mode (c)

d) The packet waiting at R1 port 2 can now be routed.

1		4	1		4
2	R1	5	2	R2	5
3		6	3		6
			(d)

Figure 8-28 Source Node Stalled: Watchdog Mode (d)

Preliminary 100