Opis: This paper describes data structures and algorithms for representation of Boolean functions with reduced ordered binary decision diagrams (ROBDDs). A hash table is used for quick search. Additional information about variables and functions is stored in binary trees. Manipulations on functions are based on a recursive algorithm of ITE operation. The primary goal of this article is describe programming technics needed to realize the idea. For the first time here recursive algorithms for composing functions and garbage collection with a formulae counter are presented. This is better than garbage collection in other known implementations. The results of the tests show that the described representation is very efficient in applications which operate with Boolean functions. Ključne besede:Reduced Ordered Binary Decision Diagram, Boolean function, logic functions, logic design verification, hash table Objavljeno v DKUM: 02.02.2018; Ogledov: 2321; Prenosov: 53 Celotno besedilo (323,32 KB)

Opis: General decision diagram is a loose term for a superset of different types of decision diagrams - we are interested in joining BDDs, FDDs, and different types of suppressed DDs, e.g. ZBDDs. I will present: The current state of our BDD package Biddy (functionalities and details about the original implementation aspects). Our ideas for efficient implementation of ZBDDs (which could be used for all types of suppressed DDs).New type od decision diagrams called ZFDD (somehow symmetric to ZBDD). A rough draft about the implementation of a package supporting general decision diagrams. Ključne besede:Binary Decision Diagram, Zero-suppressed Binary Decision Diagram, Boolean function, Algorithm, BDD package, Biddy Objavljeno v DKUM: 26.10.2017; Ogledov: 3214; Prenosov: 113 Celotno besedilo (1,07 MB)

Opis: Binary decision diagram (BDD) is a very successful data structure for
representation and manipulation of Boolean functions. Various BDD types
have been proposed. In this paper relations between OBDD, OFDD, and
0-sup-BDD are shown in a new way. An universal decomposition rule for them
is introduced. Using this rule a set of 288 BDD types is defined
together with their minimization rules.
NOTE: This is a revisited and translated version of the paper: "Splošno razčlenitveno pravilo za OBDD, OFDD in 0-sup-BDD". In Proceedings of the Fifth Electrotechnical and Computer Science Conference ERK'96, Portorož, Slovenia, volume B, pages 11-14, September 1996. Ključne besede:Binary Decision Diagram, Shannon's expansion, Reed–Muller expansion, Davio expansion, Digital Circuit Design Objavljeno v DKUM: 12.10.2016; Ogledov: 2293; Prenosov: 83 Celotno besedilo (235,92 KB)