Too Few or Too Many Properties? Measure it by ATPG!

Abstract

Verification of a design, based on model checking, requires the identification of a set of formal properties manually derived from the specification of the design under verification (DUV). Such a set can include too few or too many properties. This paper proposes to use a functional ATPG to identify missing properties and to remove unnecessary ones. In particular, the paper refines, extends, and compares, with other symbolic approaches, a methodology to estimate the completeness of formal properties, which exploits a functional fault model and a functional ATPG. Moreover, the same fault model and ATPG are used to face the opposite problem of identifying useless properties, that is, properties which are in logical consequence. Logical consequence between properties is generally examined by using theorem proving, which may require a large amount of time and space resources. On the contrary, the paper proposes a faster approach which analyzes logical consequence by observing the property capability of revealing functional faults. The joint use of the methodologies allows to optimize the set of properties used for several verification sessions needed to check all design phases of an incremental design flow.