Back-Tracing and Event-Driven Techniques in High-Level Simulation with Decision Diagrams

The paper addresses the problem of the cycle-based simula-tion performance of synchronous digital systems modeled by the High-Level Decision Diagrams (DDs). A new class of DD repre-sentation, called Register-Oriented DDs (RODD) is introduced. RODD model appears to be an efficient and compact represen-tation of the system behavior for the high-level cycle simulation. In order to filly exploit the advantages of RODDs a new simula-tion algorithm, which is a combination of cycle-based forward event-driven and recursive back-tracing techniques is proposed. The characteristics of the simulation algorithms used to effi-ciently execute the evaluation of DD network are discussed. Further the experimental results carried out on the real case ex-amples demonstrating the gain in simulation performance of the proposed approach and a comparison of four cycle-based simu-lation algorithms are presented. Additionally, a comparison with the commercial event-driven and cycle-based HDL simulation tools is included. 1