Multi-valued Simulation with Binary Decision Diagrams

The paper presents a new method for multivalued simulation of digital circuits based on calculation of Boolean derivatives on BDDs (or structural alternative graphs). A procedure for calculation of maximums of Boolean derivatives as the basis of multivalued simulation is given. The method is applicable for component level representations of digital circuits where as components arbitrary subcircuits (macros) instead of gates are considered. No dedicated model library for multivalued simulation is needed. Instead of dedicated multi-valued models, generic ones in the form of BDDs are used. Implementation areas of multivalued simulation for delay fault testing and hazard analysis are discussed. Advantages of the new approach compared to the traditional gate-level multivalued simulation are shown. Experimental data for ISCAS benchmarks to demonstrate these advantages are also included.