Atmel SpaceWire Router SpW-10X User Manual

Page of 155
Ref.:   UoD_SpW-10X_ 
UserManual
 
Issue:  3.4 
  
 
 
SpW-10X 
SpaceWire Router 
User Manual 
Date:  11
th
 July 2008 
 
 
Preliminary 
99
 
R1
1
2
3
4
5
6
(a)
4
5
R2
1
4
2
3
5
6
4
4
 
Figure 8-21 Source Node Stalled (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 further data or the end of packet. 
R1
1
2
3
4
5
6
(b)
R2
1
4
2
3
5
6
4
4
 
Figure 8-22 Source Node Stalled (b) 
c)  The packet is blocked and the packet waiting at routing switch R1 port 2 cannot be routed.  
R1
1
2
3
4
5
6
(c)
R2
1
4
2
3
5
6
4
4
 
Figure 8-23 Source Node Stalled (c) 
d)  After an undetermined time the source node supplies the remaining data and end of packet 
and the packet waiting at R1-2 can be routed. 
R1
1
2
3
4
5
6
(d)
R2
1
4
2
3
5
6
 
Figure 8-24 Source Node Stalled (d) 
Watchdog Timer Mode 
What happens when a source stalls and Watchdog Timer mode is being used is illustrated in Figure 
8-25 to Figure 8-28: 
a)  A packet arrives at routing switch port 3 with destination address 4, 5 which will route to 
routing switch R2 port 5. Another packet arrives which is destined for routing switch R2 port 4.