Channel Multiplexing in Fault-Tolerant Modular Multiprocessors

Abstract

A systematic approach to the design of fault-tolerant multiprocessors is described in this paper. This design approach utilizes the concept of multiplexing different channels of communication links to reconfigure fault-tolerant systems in the presence of faults. It is a simple approach which can be applied to different modular architectures and can implement different spare allocation strategies. In this paper, we derive the theoretical bounds of the channel requirement per link to reconfigure the system properly and utilize all the available spare nodes. For some links, this bound is as high as 2m, where m is the degree of a node. However, it is shown that a constant number of channels per link allows the system to be reconfigured properly and to utilize all the available spare nodes almost 100% of the time. We apply this approach to the construction of fault-tolerant binary trees and fault-tolerant binary hypercubes.