OBDD variable ordering by interleaving compacted clusters

An effective method for variable ordering of OBDDs (ordered binary decision diagrams) based on the interleaving of the compacted clusters is proposed. The novelty of this method lies in the application of the divide-and-conquer approach to efficiently find a good variable ordering for circuits with a large number of I/Os. One notable result from this method is that the OBDD is able to be built using the cs38417 circuit, the remaining unreported circuit in the ISCAS89 benchmark