Bi-decomposing large Boolean functions via interpolation and satisfiability solving.
Journal
Proceedings of the 45th Design Automation Conference, DAC 2008, Anaheim, CA, USA, June 8-13, 2008
Pages
636-641
Date Issued
2008
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 XA,XB,XC on X if it can be written as h(fA(XA,XC),fB(XB, XC)) 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| ã |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.
Type
conference paper