Reducing BDD size by exploiting structural connectivity

Abstract

Computer-aided design tools have been limited by the use of the Binary Decision Diagram (BDD). The major drawback of the BDD is its abundant usage of CPU time and memory. Techniques such as BDD variable ordering and sharing have been used in the past to address the size issue. However these techniques remain to be limited to modest-sized circuits. In this paper, we present a significant variation to the conventional BDD, the Connective Binary Decision Diagram (CBDD). The CBDD addresses the size issue concerning conventional BDD implementations by employing the use of minimized-scalable binary decision diagrams (MSBDDs) combined with the structural connectivity present in the circuit's netlist. The experimental results section will demonstrate that the proposed method reduces the BDD size by more than two orders of magnitude for large circuits.