Abstract
Because scan chain failure is responsible for a large percentage of yield loss, scan chain diagnosis has become a critical issue in modern technology. In this paper, we present a scan chain reordering algorithm to improve scan chain fault diagnosis resolution. The ordering of scan cells is performed to decrease the range of suspect faulty scan cells by a bipartite matching reordering algorithm. Then simulated annealing algorithm is used to refine the wire length overhead. The experimental results show that our approach can effectively reduce the number of suspect scan cells for most cases of ITC'99 benchmarks.