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124
Graphbased algorithms for Boolean function manipulation
 IEEE TRANSACTIONS ON COMPUTERS
, 1986
"... In this paper we present a new data structure for representing Boolean functions and an associated set of manipulation algorithms. Functions are represented by directed, acyclic graphs in a manner similar to the representations introduced by Lee [1] and Akers [2], but with further restrictions on th ..."
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Cited by 3393 (52 self)
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In this paper we present a new data structure for representing Boolean functions and an associated set of manipulation algorithms. Functions are represented by directed, acyclic graphs in a manner similar to the representations introduced by Lee [1] and Akers [2], but with further restrictions on the ordering of decision variables in the graph. Although a function requires, in the worst case, a graph of size exponential in the number of arguments, many of the functions encountered in typical applications have a more reasonable representation. Our algorithms have time complexity proportional to the sizes of the graphs being operated on, and hence are quite efficient as long as the graphs do not grow too large. We present experimental results from applying these algorithms to problems in logic design verification that demonstrate the practicality of our approach.
Symmetry Detection and Dynamic Variable Ordering of Decision Diagrams
, 1996
"... Knowing that some variables are symmetric in a function has numerous applications; in particular, it can help produce better variable orders for Binary Decision Diagrams (BDDs) and related data structures (e.g., Algebraic Decision Diagrams). It has been observed that there often exists an optimum ..."
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Cited by 65 (2 self)
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Knowing that some variables are symmetric in a function has numerous applications; in particular, it can help produce better variable orders for Binary Decision Diagrams (BDDs) and related data structures (e.g., Algebraic Decision Diagrams). It has been observed that there often exists an optimum order for a BDD wherein symmetric variables are contiguous. We propose a new algorithm for the detection of symmetries, based on dynamic reordering, and we study its interaction with the reordering algorithm itself. We show that combining sifting with an efficient symmetry check for contiguous variables results in the fastest symmetry detection algorithm reported to date and produces better variable orders for many BDDs. The overhead on the sifting algorithm is negligible. 1
Symbolic manipulation of boolean functions using a graphical representation
 In DAC
, 1985
"... In this paper we describe a data structure for representing Boolean functions and an associated set of manipulation algorithms. Functions are represented by directed, acyclic graphs in a manner similar to the representations of Lee and Akers, but with further restrictions on the ordering of decision ..."
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Cited by 63 (2 self)
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In this paper we describe a data structure for representing Boolean functions and an associated set of manipulation algorithms. Functions are represented by directed, acyclic graphs in a manner similar to the representations of Lee and Akers, but with further restrictions on the ordering of decision variables in the graph. Although a function requires, in the worst case, a graph of size exponential in the number of arguments, many of the functions encountered in typical applications have a more reasonable representation. Our algorithms are quite efficient as long as the graphs being operated on do not grow too large. We present performance measurements obtained while applying these algorithms to problems in logic design verification.
COSMOS: A compiled simulator for MOS circuits
 PROCEEDINGS OF THE 24TH DESIGN AUTOMATION CONFERENCE
, 1987
"... The cosmos simulator provides fast and accurate switchlevel modeling of mos digital circuits. It attains high performance by preprocessing the transistor network into a functionally equivalent Boolean representation. This description, produced by the symbolic analyzer anamos, captures all aspects o ..."
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Cited by 63 (0 self)
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The cosmos simulator provides fast and accurate switchlevel modeling of mos digital circuits. It attains high performance by preprocessing the transistor network into a functionally equivalent Boolean representation. This description, produced by the symbolic analyzer anamos, captures all aspects of switchlevel networks including bidirectional transistors, stored charge, different signal strengths, and indeterminate (X) logic values. The lgcc program translates the Boolean representation into a set of machine language evaluation procedures and initialized data structures. These procedures and data structures are compiled along with code implementing the simulation kernel and user interface to produce the simulation program. The simulation program runs an order of magnitude faster than our previous simulator mossim ii.
A simple DNA gate motif for synthesizing largescale circuits
"... Abstract. The prospects of programming molecular systems to perform complex autonomous tasks has motivated research into the design of synthetic biochemical circuits. Of particular interest to us are cellfree nucleic acid systems that exploit noncovalent hybridization and strand displacement react ..."
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Cited by 38 (6 self)
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Abstract. The prospects of programming molecular systems to perform complex autonomous tasks has motivated research into the design of synthetic biochemical circuits. Of particular interest to us are cellfree nucleic acid systems that exploit noncovalent hybridization and strand displacement reactions to create cascades that implement digital and analog circuits. To date, circuits involving at most tens of gates have been demonstrated experimentally. Here, we propose a DNA catalytic gate architecture that appears suitable for practical synthesis of largescale circuits involving possibly thousands of gates. 1
Active zones in CSG for accelerating boundary evaluation, redundancy elimination, interference detection, and shading algorithms
 ACM Transactions on Graphics
, 1989
"... Solids defined by Boolean combinations of solid primitives may be represented in constructive solid geometry (CSG) as binary trees. Most CSGbased algorithms (e.g., for boundary evaluation, graphic shading, interference detection) do various forms of setmembership classification by traversing the t ..."
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Cited by 27 (8 self)
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Solids defined by Boolean combinations of solid primitives may be represented in constructive solid geometry (CSG) as binary trees. Most CSGbased algorithms (e.g., for boundary evaluation, graphic shading, interference detection) do various forms of setmembership classification by traversing the tree associated with the solid. These algorithms usually generate intermediate results that do not contribute to the final result, and hence may be regarded as redundant and a source of inefficiency. To reduce such inefficiencies, we associate with each primitive A in a tree S an active zone 2 that represents the region of space where changes to A affect the solid represented by S, and we use a representation of 2 instead of S for setmembership classification. In the paper we develop a mathematical theory of active zones, prove that they correspond to the intersection of certain nodes of the original trees, and show how they lead to efficient new algorithms for boundary evaluation, for detecting and eliminating redundant nodes in CSG trees, for interference (nullset) detection, and for graphic shading.
Algorithmic Aspects of Symbolic Switch Network Analysis
 IEEE Trans. CAD/IC
, 1987
"... A network of switches controlled by Boolean variables can be represented as a system of Boolean equations. The solution of this system gives a symbolic description of the conducting paths in the network. Gaussian elimination provides an efficient technique for solving sparse systems of Boolean eq ..."
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Cited by 22 (5 self)
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A network of switches controlled by Boolean variables can be represented as a system of Boolean equations. The solution of this system gives a symbolic description of the conducting paths in the network. Gaussian elimination provides an efficient technique for solving sparse systems of Boolean equations. For the class of networks that arise when analyzing digital metaloxide semiconductor (MOS) circuits, a simple pivot selection rule guarantees that most s switch networks encountered in practice can be solved with O(s) operations. When represented by a directed acyclic graph, the set of Boolean formulas generated by the analysis has total size bounded by the number of operations required by the Gaussian elimination. This paper presents the mathematical basis for systems of Boolean equations, their solution by Gaussian elimination, and data structures and algorithms for representing and manipulating Boolean formulas.
Constructive multilevel synthesis by way of functional properties
 Ph.D. dissertation, Comput. Sci. Eng., Univ. Michigan, Ann Arbor
, 2001
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