An efficient parallel critical path algorithm

Abstract

The problem of identifying one of the longest sensitizable paths in a circuit is called criti- cal path problem. Several critical path algorithms have been proposed in the last few years. However, due to the long computation time required to produce accu- rate results these algorithms may not be able to gen- erate any result for large designs with many long false paths unless the accuracy of the results is compromised. Parallel processing seems to be an appropriate way to speed up the required computation. In this paper we studied the parallel algorithms for critical path prob- lem. We first present a sensitization criterion. Based on this sensitization criterion the DT-algorithm, which is a variation of the D-algorithm with stable time range of signals also taken into consideration, is developed. It is especially suitable to determine the sensitizability of a given path in a parallel processing environment. We also discussed a parallel implementation of the criti- cal path algorithm on a shared-memory multiproces- sor. The experimental results show that a reasonable speed-up can be obtained.