Synopsys, Inc.

Rachid Helaihel

Kayhan Kucukcakar

Khalid Rahmat

Peivand Tehrani

Song Chen

Sarvesh Bhardwaj

Hushrav Mogal

Cristian Soviani

Disclosed is a method and apparatus that takes timing information associated with a plurality of inputs to a cell, such as an AND-gate, within an integrated circuit (IC) design, store the timing information in a timing information register (TIR) associated with an index identifying the source of the timing information and track the source of the timing information for a predetermined number of cells through the index. The timing information in the TIRs is merged upon the index indicating that the timing information has been tracked through a predetermined number of cells.

Method and apparatus for reducing pessimism of graph based static timing analysis

A system and a method are disclosed for reducing memory used in storing totals during static timing analysis. Totals are stored at various points along paths analyzed in static timing analysis. Some totals may not be merged for reasons including differing clock re-convergence pessimism removal (CRPR) dominators, exceptions, or clocks. Totals at a point may be stored in a super-tag mapping table and replaced at the point with a super-tag. The super-tag includes a super-tag ID referencing the totals stored in the super-tag mapping table. The super-tag also includes a time delay value. The time delay value allows the super-tag ID to be reused in other super-tags at other points while still storing total time delays at the other points. Therefore, the memory used to store totals is reduced in many situations.

Reducing memory used to store totals in static timing analysis

One embodiment of the present invention provides a system that performs an efficient path-based static timing analysis (STA) in a circuit design. During operation, the system identifies a set of paths within the circuit design, wherein each path includes one or more segments. For a path in the set of paths, the system determines if at least one segment in the path is shared with a different path which was previously computed by performing a path-based STA, wherein the at least one segment in the different path is associated with previously computed path-based timing information. If so, the system then performs an estimation of a path-based delay for the path based at least on the path-based timing information associated with the shared segment in the different path. Otherwise, the system computes a path-based delay for the path by performing a path-based STA on the path.

Efficient exhaustive path-based static timing analysis using a fast estimation technique

A method and system of optimizing exceptions to default timing constraints for use in integrated circuit design tools is described. A list of exceptions is accessed and optimized to generate a new list of exceptions. Optimizations may include: elimination of redundant information, resolution of conflicting information, and other transformations. The new list allows more efficient timing analysis, synthesis, placement, routing, noise analysis, power analysis, reliability analysis, and other operations to be performed by EDA tools.

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Mountain View, CA, United States of America

Rachid Helaihel