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CMU-CS-03-191
Computer Science Department
School of Computer Science, Carnegie Mellon University
CMU-CS-03-191
A SAT-Based Algorithm for Reparameterization
in Symbolic Simulation
Pankaj Chauhan, Daniel Kroening, Edmund Clarke
December 2003
CMU-CS-03-191.ps
CMU-CS-03-191.pdf
Keywords: Symbolic simulation, SAT checkers, bounded model checking,
parametric representation, safety property checking
Parametric representations used for symbolic simulation of circuits
usually use BDDs. After a few steps of symbolic simulation, state set
representation is converted from one parametric representation to
another smaller representation, in a process called
reparameterization. For large circuits, the reparametrization step
often results in a blowup of BDDs and is expensive due to a large
number of quantifications of input variables involved. Efficient SAT
solvers have been applied successfully for many verification
problems. This paper presents a novel SAT-based reparameterization
algorithm that is largely immune to the large number of input
variables that need to be quantified. We show experimental results on
large industrial circuits and compare our new algorithm to both
SAT-based Bounded Model Checking and BDD-based symbolic simulation.
We were able to achieve on average 3x improvement in time and space
over BMC and able to complete many examples that BDD-based approach
could not even finish.
29 pages
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