Reliable design of large crosspoint switching networks

Abstract

A major source of transient errors and unreliable operation of large crosspoint switching networks is the simultaneous switching ( Delta I) noise that is caused by the switching of a large number of off-chip drivers in a chip. An architectural solution to this problem is presented for networks constructed from one-sided crosspoint switching chips. The method seeks to achieve a uniform distribution of active drivers among the chips by rearranging a subset of the existing connections when a new connection is made. The problem is studied in the context of a one-sided crosspoint network with N=rn ports constructed from individual switching chips of size n*m/2. The authors show that the lower bound of m/r active drivers per chip can always be maintained in practice when m/r is an even number. The maximum number of rearrangements needed is min(m/2-1, 2r-1). In addition, the rearrangements are confined to two chip columns of the matrix.<>