ASP-DAC 2004: Asia and South Pacific Design Automation Conference 2004 (IEEE Cat. No.04EX753)
DOI: 10.1109/aspdac.2004.1337660
|View full text |Cite
|
Sign up to set email alerts
|

Efficient computation of canonical form for boolean matching in large libraries

Abstract: Abstract-This paper presents an efficient technique for solving a Boolean matching problem in cell-library binding, where the number of cells in the library is large. As a basis of the Boolean matching, we use the notion NP-representative (NPR); two functions have the same NPR if one can be obtained from the other by a permutation and/or complementation(s) of the variables. By using a table look-up and a tree-based breadthfirst search strategy, our method quickly computes NPR for a given function. Boolean matc… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
2
2
1

Citation Types

1
23
0

Publication Types

Select...
3
3
3

Relationship

0
9

Authors

Journals

citations
Cited by 21 publications
(24 citation statements)
references
References 19 publications
1
23
0
Order By: Relevance
“…Previous work on Boolean matching differs from the proposed algorithm in that (a) it targets large functions [2], (b) it is inherently BDD-based and therefore not nearly as fast [3][6], (c) it is limited to only permutation of inputs without considering their complementation [10], (d) it is not scalable due to high computational complexity of some computations, such as implicant table generation [8] [9]. This paper presents two algorithms: a fast heuristic one and a slower nearly-exact one.…”
Section: Introductionmentioning
confidence: 99%
“…Previous work on Boolean matching differs from the proposed algorithm in that (a) it targets large functions [2], (b) it is inherently BDD-based and therefore not nearly as fast [3][6], (c) it is limited to only permutation of inputs without considering their complementation [10], (d) it is not scalable due to high computational complexity of some computations, such as implicant table generation [8] [9]. This paper presents two algorithms: a fast heuristic one and a slower nearly-exact one.…”
Section: Introductionmentioning
confidence: 99%
“…[6] improves the approach by pruning the search tree, using signatures (including first order cofactors) and symmetry checks. These approaches are slower than canonical form based methods [1], except for very small numbers of input variables, but their main drawback is the large memory requirements, which effectively limit its applicability to functions with up to a maximum of dozen variables [6], [9]. Canonical form-based approaches, on the other hand, scales well up to over twenty input variables.…”
Section: Related Workmentioning
confidence: 99%
“…Finally, other approaches such as [6], [9] rely on a preliminary exploration of the function space that allows the precomputation of minterm positions. This information is then saved into huge lookup tables.…”
Section: Related Workmentioning
confidence: 99%
“…Recall from Section 2.5, that two functions INTEGRATED TECHNOLOGY MAPPING algorithm OptimalDelayCover(v, P) /* v is a graph vertex, P is set of library patterns */ for u ∈ f anin(v) do OptimalDelayCover(u, P) for γ ∈ Γ(v) do /* Γ(v) is the set of possible load intervals at v */ cost(v, γ) : are NPN-equivalent if one can be obtained from the other by negation and/or permutation of the inputs and outputs. The dominant approach for Boolean matching is to compute for each library cell a canonical (or semi-canonical) form that is an invariant with respect to input/output and store it in a hash table [145,146,147,148,149]. To attempt a match for a subgraph, the matcher computes the canonical form for the associated function and looks it up in a hash table.…”
Section: Technology Mappingmentioning
confidence: 99%