# Computing Boolean Expressions with OBDDs

### T.R. Shiple, Robert K. Brayton and Alberto L. Sangiovanni-Vincentelli

###
EECS Department

University of California, Berkeley

Technical Report No. UCB/ERL M93/84

1993

We present a method to compute the BDD for an arbitrary Boolean expression, where the operands are themselves BDDs. Such expressions are usuaLly computed by the successive application of binary operators. However, Cases exist where this method performs wasteful intermediate computations and creates BDD nodes not used in the final result. In contrast, our method never creates a BDD node unless it is present in the final result. We tested the new method on the application of building BDDs for the nodes in a multi-level logic network. Although the new method uses fewer BDD nodes, its runtime is much worse. By analyzing the reasons for this, we further our understanding of BDD operations.

BibTeX citation:

@techreport{Shiple:M93/84, Author = {Shiple, T.R. and Brayton, Robert K. and Sangiovanni-Vincentelli, Alberto L.}, Title = {Computing Boolean Expressions with OBDDs}, Institution = {EECS Department, University of California, Berkeley}, Year = {1993}, URL = {http://www.eecs.berkeley.edu/Pubs/TechRpts/1993/2456.html}, Number = {UCB/ERL M93/84}, Abstract = {We present a method to compute the BDD for an arbitrary Boolean expression, where the operands are themselves BDDs. Such expressions are usuaLly computed by the successive application of binary operators. However, Cases exist where this method performs wasteful intermediate computations and creates BDD nodes not used in the final result. In contrast, our method never creates a BDD node unless it is present in the final result. We tested the new method on the application of building BDDs for the nodes in a multi-level logic network. Although the new method uses fewer BDD nodes, its runtime is much worse. By analyzing the reasons for this, we further our understanding of BDD operations.} }

EndNote citation:

%0 Report %A Shiple, T.R. %A Brayton, Robert K. %A Sangiovanni-Vincentelli, Alberto L. %T Computing Boolean Expressions with OBDDs %I EECS Department, University of California, Berkeley %D 1993 %@ UCB/ERL M93/84 %U http://www.eecs.berkeley.edu/Pubs/TechRpts/1993/2456.html %F Shiple:M93/84