Stability metrics for placement to quantify the stability of placement algorithms
US7073144B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 2004 |
| Grant date | Jul 4, 2006 |
| Priority date | — |
| Expiry date | Aug 13, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F30/392
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method of assessing the stability of a placement tool used in designing the physical layout of an integrated circuit chip, by constructing different layouts of cells using the placement tool with different sets of input parameters, and calculating a stability value based on the movement of respective cell locations between the layouts. The stability value can be normalized based on cell locations in a random placement. One stability metric measures absolute movement of individual cells in the layouts, weighted by cell area. The cell movements can be squared in calculating the stability value. Another stability metric measures the relative movement of cells with respect to their nets. Shifting of cells and symmetric reversal of cells about a net center does not contribute to this relative movement, but spreading of cells and rotation of cells with respect to the net center does contribute to the relative movement. Relative cell movements can again be squared in calculating the stability value. Many different layouts can be designed using the same placement tool with a range of different input parameters and different movement metrics to build a collection of comparative values tha…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.