International Business Machines Corporation

Jeffrey Mark Ritzinger

Eric A Foreman

Peter Anton Habitz

Kerim Kalafala

Ronald Nick Kalla

Debjit Sinha

Nathan C Buck

Gavin Balfour Meil

John P Dubuque

Soroush Abbaspour

Adil Bhanji

Xiaoyue X Wang

Jack DiLullo

In accordance with an aspect of the present invention, specifying a portion of a circuit design to be treated as untimed by static timing analysis is performed on the RTL design by means of an attribute annotation. The process is operable to map through to the Physical Design by correlating latches and chip-level nets. This allows the testing process to become closed-loop. Design and simulation time is also greatly reduced due to the accessibility of RTL design.

Specifying and validating untimed nets

A method for converting interconnect parasitics of an interconnect network into slew dependent pin capacitances utilizes charge matching between predetermined voltage thresholds. During timing abstraction of a macro, parasitics of interconnects connected to the primary inputs are represented as slew dependent pin capacitances in an abstract model being created. Interconnect model order reduction is employed to speed the process. The generated abstract is subsequently used in place of each occurrence of the macro during chip level hierarchical static timing analysis, leading to an enhanced accuracy of the timing analysis of the logic components driving the abstracts.

Method of employing slew dependent pin capacitances to capture interconnect parasitics during timing abstraction of VLSI circuits

A method and system for reducing a number of paths to be analyzed in a multi-corner static timing analysis. An estimated upper slack variation based on a non-common path delay for a racing path is utilized in determining if a multi-corner static timing analysis may be bypassed for a racing path. In another example, an estimated maximum RSS credit based on a total delay for a racing path is utilized in determining if a multi-corner static timing analysis may be bypassed for a racing path.

Estimation of process variation impact of slack in multi-corner path-based static timing analysis

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Chippewa Falls, WI, United States of America

Jeffrey Mark Ritzinger