SMT-based stimuli generation in the SystemC Verification library

Modelling at the electronic system level (ESL) is the established approach of the major system-on-chip (SoC) companies. While in the past ESL design covered design methodologies only, today also verification and debugging is included. To improve the verification process, testbench automation has been introduced highlighted as constraint-based random simulation. In SystemC - the de facto standard modelling language for ESL - constraint-based random simulation is available through the SystemC verification (SCV) library. However, the underlying constraint-solver is based on binary decision diagrams (BDDs) and hence suffers from memory problems. In this paper, we propose the integration of new techniques for stimuli generation based on satisfiability modulo theories (SMT). Since SMT solvers are designed to determine a single satisfying solution only, several strategies are proposed forcing the solver to generate more than one stimuli from different parts of the search space. Experiments demonstrate the advantage of the proposed approach and the developed strategies in comparison to the original BDD-based method.