
152 Communication Architectures for SoC
destination. Whereas, in a multiswitch case, this may not happen, for exam-
ple, if there are 3 flows to the same destination. In the multiswitch case, two
of them may share a path until a point where they contend with the third
flow. The third flow only has to wait for one of them (with the maximum
delay) to go through. Whereas, in a full crossbar, the third flow will have to
wait for both the flows, in the worst case. Thus, we can see that, when only
few flows require real-time guarantees a multiswitch topology can give better
bounds and it is really difficult to come with the best topology directly using
designer’