Minimization of free BDDs

Author

Günther, Wolfgang ; Drechsler, Rolf

Author_Institution

Inst. of Comput. Sci., Albert-Ludwigs-Univ., Freiburg, Germany

fYear

1999

fDate

18-21 Jan 1999

Firstpage

323

Abstract

Free BDDs (FBDDs) are an extension of ordered BDDs (OBDDs). FBDDs may have different orderings along each path. They allow a more efficient representation, while keeping (nearly) all of the properties of OBDDs. In some cases even an exponential reduction can be observed. In this paper we present for the first time an exact algorithm for finding a minimal FBDD representation for a given Boolean function. To reduce the huge search space, it makes use of a pruning technique. The algorithm also considers symmetries of the function. Since the algorithm is only applicable to small functions, we also present a heuristic for FBDD minimization starting from an OBDD. Our experiments show that in many cases significant improvements can be obtained

Keywords

Boolean functions; binary decision diagrams; minimisation; Boolean function; FBDD minimization; exponential reduction; free BDDs; function symmetries; minimal FBDD representation; ordered BDD; pruning technique; Binary decision diagrams; Boolean functions; Circuit synthesis; Circuit testing; Computer science; Data structures; Minimization methods; Very large scale integration;

fLanguage

English

Publisher

ieee

Conference_Titel

Design Automation Conference, 1999. Proceedings of the ASP-DAC '99. Asia and South Pacific

Conference_Location

Wanchai

Print_ISBN

0-7803-5012-X

Type

conf

DOI

10.1109/ASPDAC.1999.760024

Filename

760024