A class of fault-tolerant cellular permutation networks

A scheme for fault-tolerant triangular cellular interconnection networks is proposed. A fault model is defined which unifies the concept of usable and unusable faulty components. An algorithm for testing these networks with a minimal number of tests (8) is presented. This result is extended to other cellular networks. A constant number of tests independent of the network size (at most 8) is added, in order to locate the faulty cell in the triangular cellular interconnection networks. Then, by considering networks of n+2 instead of n inputs/outputs, any single faulty cell can be tolerated. Neither the complexity of the cell nor that of the links is increased. The programming of the fault tolerant network is of the same complexity as that of the fault-free network and the relative silicon area overhead decreases with n and is proportional to 4/n