Polynomial testing of packet switching networks

A functional testing method called polynomial testing is proposed to test packet-switching networks (PSNs) used in multiprocessor systems. Focus is on applying the method to packet-switching multistage interconnection networks (PMINs). A multiple stuck-at (MSA) fault model is developed and faults are diagnosed at two different levels: network level and switch level. The former uses each processor as a tester and can test part of the network concurrently with the normal operations on the remaining part of the network; the latter uses switches in the network as testers and is inherently an autonomous testing method. To facilitate the network-level testing, the routing dynamic in a PMIN is eliminated by synchronizing switch operations. The network is then decomposed into routes, each of which is tested after transforming it into a polynomial calculator. For switch-level testing, a built-in tester (BIT) is embedded into each switch´s structure to provide self-testing capabilities. Network-level testing is distributed and suitable for concurrent testing, whereas switch-level testing is done offline, and needs only a small testing time.<>