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Logic Synthesis n -Basic Concepts and Tools n Tao Lin n Ohio Universtiy n February 17, 1998.

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Presentation on theme: "Logic Synthesis n -Basic Concepts and Tools n Tao Lin n Ohio Universtiy n February 17, 1998."— Presentation transcript:

1 Logic Synthesis n -Basic Concepts and Tools n Tao Lin n Ohio Universtiy n February 17, 1998

2 n Introductory to some basic concepts; n Espresso; n Brief description to the BDD (Binary Decision Diagram).

3 F oundation for: n combinational and sequential synthesis n testing n timing and false paths n formal verication n asynchronous synthesis n automata theory n optimal clocking schemes n hazard analysis n power estimation n general combinatorics.

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5 if f 1 = B n, f is the tautology, i.e. f  1; if f 0 = B n, (f 1 =  ) f is not satisfiable; if f(x) = g(x) for all x  B n, then f and g are equivalent; x 1 ; x 2 ; … are variables; x 1 ; x 1 ; x 2 ; x 2 ; … are literals;

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11 A cover is prime irredundant if all its cubes are prime (irredundant). A prime of f is essential (essential prime) if there is a min-term (essential vertex) in that prime but in no other prime.

12 Shannon (Boole) Cofactors

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15 Binary Recursion Tree

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17 Unate Functions and Unate Covers A function is unate in x i if it is either positive unate or negative unate in x i.

18 Unate covers F have many extraordinary properties:  If a cover F is minimal with respect to singlecube containment, all of its cubes are essential primes.  In this case F is the unique minimum cube repre- sentation of its logic function.  A unate cover represents the tautology iff it contains a cube with no literals, i.e. a single tautologous cube.

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22 IRREDUNDANT

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25 EXPAND

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27 Main idea of EXPAND

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29 REDUCE

30 Reduce is order dependent.

31 REDUCE Algorithm

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36 Unate Algorithm for SCCC

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42 LSTGASP

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46 A Brief Description of BDD (Binary Decision Diagram)

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54 Acknowledgement n Most of the materials used here were selected from EE219b course note of UC- Berkeley. The author of these notes is Mr. R.K.Brayton. n Many thanks to people who give me help on preparing this talk.


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