Method for reducing RC parasitics in interconnect networks of an integrated circuit
US6763504B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 2002 |
| Grant date | Jul 13, 2004 |
| Priority date | — |
| Expiry date | Dec 19, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F30/367
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for further reducing RC parasitics in an interconnect network following internal node elimination is described. A resistor is initially selected as a candidate for shorting, and it is established whether the accumulated delay error at either end of the resistor is less than a predetermined threshold. This threshold must be a fraction of the time-constant threshold selected by internal node elimination techniques in order to limit the growth of the accumulated delay errors. An important aspect of the invention is the simplicity of the formula used to change the downstream resistor values, namely, the product of the value of the resistor shorted and the ratio of the cumulative downstream capacitances of the two ends of the resistor whose value is being changed. This particular choice of updating the downstream resistor values minimizes the absolute-value of the delay errors at every node due to shorting of the selected resistor. It also preserves the delays at all nodes in the interconnect network apart from the two ends of the resistor selected for shorting.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.