Bi-Decomposing Large Boolean Functions via Interpolation and Satisfiability Solving
Journal
ACM/IEEE Design Automation Conference (DAC'08)
Pages
636-641
Date Issued
2008-06
Author(s)
Abstract
Boolean function bi-decomposition is a fundamental operation in logic synthesis. A function f(X) is bi-decomposable under a variable partition X A,XB,XC on X if it can be written as h(f A(XA, XC), fB(XB, X C)) for some functions h, fA, and fB. The quality of a bi-decomposition is mainly determined by its variable partition. A preferred decomposition is disjoint, i.e. XC = ø, and balanced, i.e. |XA| ≈ |XB|. Finding such a good decomposition reduces communication and circuit complexity, and yields simple physical design solutions. Prior BDD-based methods may not be scalable to decompose large functions due to the memory explosion problem. Also as decomposability is checked under a fixed variable partition, searching a good or feasible partition may run through costly enumeration that requires separate and independent decomposability checkings. This paper proposes a solution to these difficulties using interpolation and incremental SAT solving. Preliminary experimental results show that the capacity of bi-decomposition can be scaled up substantially to handle large designs. Copyright 2008 ACM.
Type
conference paper