Mutant Fault Injection in Functional Properties of a Model to Improve Coverage Metrics

This paper proposes integrating mutation analysis into model checking to improve coverage metrics of digital circuits. In contrast to traditional mutation testing where mutant faults are generated and injected into the code description of the model, we apply a series of newly defined mutation operators directly to the model properties rather than to the model code. We claim that any mutant properties that are generated from the initial properties and validated by the model checker should be considered as new properties that have been missed during the initial verification procedure. Therefore, adding these newly identified properties to the existing list of properties improves the coverage metric of the formal verification and consequently lead to a more reliable design. Preliminary simulation results of applying this approach to a 4x4 Booth-Multiplier with 6 and 8 initial properties, demonstrates a 40% and 45% coverage improvement respectively compared to the initial coverage metric.