Lsi Logic Corporation

Valery B Kudryavtsev

Elyar Eldarovich Gasanov

Alexander S Podkolzin

Andrej A Zolotykh

Andrey Nikitin

The present invention includes methods for optimizing integrated circuit design by identifying a buffer tree in the integrated circuit design, the buffer tree having a plurality of vertices, each representing one of a buffer and an inverter, and also having branches, between the vertices, each representing an electrical connection. A plurality of optimization devices are applied in a random sequence to the vertices of the buffer tree. Such devices can include, for example, cell type modification; insertion of one buffer; insertion of several buffers; interchange of two grandchildren; making a grandchild into a child; making a child a grandchild; interchanging a child and a grandchild; eliminating two inverters; removing one buffer; removing more than one buffer; and removing two inverters.

Method and apparatus for dynamic buffer and inverter tree optimization

The present invention is a method for searching an identity base for identities that can be applied to a given formula. The method includes transforming the formulas from an identity base into a standard form, creating a set of code words for said identity base, constructing a lexicographical tree of a code word set of said identity base, and outputting a list of formula numbers from said identity base.

Method and apparatus for quick search for identities applicable to specified formula

A method of determining a desired connection path between a pair of points of a net separated by one or more blockages, while reducing path delays and ramp time violations and without placing buffers within any of the blockages.

Blocked net buffer insertion

The present invention comprises method for optimizing an integrated circuit design that includes computing of capacities and delays of an integrated circuit design, resynthesizing said integrated circuit design utilizing a plurality of local optimization procedures, and removing overlap the local optimization procedures can include a local resynthesis of logic trees procedure that utilizes multiple cost functions, a dynamic buffer and inverter tree optimization procedure, and a cell resizing procedure. Generally, faster local optimization procedures are applied first and slower, more thorough procedures are applied to areas where the faster procedures have not solved the optimization tasks.

Method and apparatus for timing driven resynthesis

Provided are systems and techniques for optimizing an integrated circuit design, in which a critical zone is identified in an integrated circuit design and a plurality of alternative identities are applied in the critical zone in order to obtain a corresponding plurality of outcomes. Alternative representations are then identified as those of the plurality of outcomes pursuant to which at least one of ramptime and timing are improved, and a best one of the alternative representations is selected to replace into the critical zone based on specified priorities which include: (i) selecting based on reduction in ramptime violation; (ii) selecting from among alternative representations that preserve cell area based on timing improvement; and (iii) if all alternative representations increase cell area, selecting based on an evaluation of a relationship between timing decrement and area increment.

Method and apparatus for local resynthesis of logic trees with multiple cost functions

The present invention selects parts of an integrated circuit description for resynthesis and then prepares those parts for resynthesis. Initially, a resynthesis goal is input, with the resynthesis goal having been selected from a set of possible resynthesis goals. Plural buffer and/or logic trees in the integrated circuit description are then selected based on the resynthesis goal, and information for each of the selected trees is obtained and stored. The tree information includes: (i) a description of each tree cell, including cell types, cell coordinates, and flips and angles of the tree cell, (ii) a description of each input net, (iii) a signal arrival time for each input net as a function of a capacity of such input net, (iv) coordinates of each pin driving each input net, and (v) a maximum capacity of each input net that will prevent such input net from having a timing violation.

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Moscow, Russia

Valery B Kudryavtsev