Generalized Symbolic Trajectory Evaluation Research Articles

An assertion graph based abstraction algorithm in GSTE and Its application

Generalized Symbolic Trajectory Evaluation (GSTE) is an alternative model checking technique based on particular automata to specify the properties. Despite the success of GSTE, its state explosion remains a major hurdle when applying it to large industrial designs. This paper presents two efficient theoretical underpinning abstraction algorithms based on assertion graph to combat the state explosion problem. We implement these two algorithms as a prototype system for discrete models. Experimental results show that the prototype system is 10× faster than the former without abstraction.

Terminal Satisfiability in GSTE

Generalized symbolic trajectory evaluation(GSTE) is an extension of symbolic trajectory evaluation (STE) and a method of model checking. GSTE specifications are given as assertion graphs. There are four efficient methods to verify whether a circuit model obeys an assertion graph in GSTE, Model Checking Strong Satisfiability (SMC), Model Checking Normal Satisfiability (NMC), Model Checking Fair Satisfiability (FMC), and Model Checking Terminal Satisfiability (TMC). SMC, NMC, and FMC have been proved and applied in industry, but TMC has not. This paper gives a six-tuple definition and presents a new algorithm for TMC. Based on these, we prove that our algorithm is sound and complete. It solves the SMC’s limitation (resulting in false negative) without extending from finite specification to infinite specification. At last, a case of using TMC to verify a realistic hardware circuit round-robin arbiter is achieved. Avoiding verifying the undesired paths which are not related to the specifications, TMC makes it possible to reduce the computational complexity, and the experimental results suggest that the time cost by SMC is 3.14× with TMC in the case.

A Transformation-Based Approach to Implication of GSTE Assertion Graphs

Generalized symbolic trajectory evaluation (GSTE) is a model checking approach and has successfully demonstrated its powerful capacity in formal verification of VLSI systems. GSTE is an extension of symbolic trajectory evaluation (STE) to the model checking ofω-regular properties. It is an alternative to classical model checking algorithms where properties are specified as finite-state automata. In GSTE, properties are specified as assertion graphs, which are labeled directed graphs where each edge is labeled with two labeling functions: antecedent and consequent. In this paper, we show the complement relation between GSTE assertion graphs and finite-state automata with the expressiveness of regular languages andω-regular languages. We present an algorithm that transforms a GSTE assertion graph to a finite-state automaton and vice versa. By applying this algorithm, we transform the problem of GSTE assertion graphs implication to the problem of automata language containment. We demonstrate our approach with its application to verification of an FIFO circuit.

GSTE is partitioned model checking

Verifying whether an ω-regular property is satisfied by a finite-state system is a core problem in model checking. Standard techniques build an automaton with the complementary language, compute its product with the system, and then check for emptiness. Generalized symbolic trajectory evaluation (GSTE) has been recently proposed as an alternative approach, extending the computationally efficient symbolic trajectory evaluation (STE) to general ω-regular properties. In this paper, we show that the GSTE algorithms are essentially a partitioned version of standard symbolic model-checking (SMC) algorithms, where the partitioning is driven by the property under verification. We export this technique of property-driven partitioning to SMC and show that it typically does speed up SMC algorithms.

Introduction to generalized symbolic trajectory evaluation

Symbolic trajectory evaluation (STE) is a lattice-based model checking technology that uses a form of symbolic simulation. It offers an alternative to 'classical' symbolic model checking that, within its domain of applicability, often is much easier to use and much less sensitive to state explosion. The limitation of STE, however, is that it can only express and verify properties over finite time intervals. In this paper, we present a generalized STE (GSTE) that extends STE style model checking to properties over infinite time intervals. We further strengthen the power of GSTE by introducing a form of backward symbolic simulation. It can be shown that these extensions together with a notion of fairness give STE the power to verify all /spl omega/-regular properties. The generalization also gives one the power to choose and adjust the level of model abstraction in a verification effort. We shall use a large-scale industrial memory design to demonstrate the strength and practicality of GSTE.