The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 29, 2003
Filed:
Sep. 29, 2000
Ruchir Puri, New Rochelle, NY (US);
David S. Kung, Chappaqua, NY (US);
Anthony Drumm, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A system and method are proposed for estimating interconnect delay in an Integrated Circuit (IC). A formula for effective capacitance is derived which considers the effect of slew as well as resistive shielding of capacitance, thus yielding more accurate delays for both the interconnects and the source driver (transistor gate). In the system and method, a resistor-capacitor (RC) tree model is used for iterative calculations of effective capacitance and slew for each RC tree node. The effective capacitance is determined for each node by proceeding outward from the source to the sinks, and the slew for each node is determined, using the effective capacitances just determined, by proceeding inward from the sinks to the source node. Once the source node slew determined at a previous iteration is within a specified threshold of the source node slew in the present iteration, the method stops and stores the present iteration values as the final estimates.