Automatic layout standard cell routing
US5987086A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 1996 |
| Grant date | Nov 16, 1999 |
| Priority date | — |
| Expiry date | Nov 1, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F30/394
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method of interconnecting transistors and other devices in order to optimize area of a layout of a cell while honoring performance constraints (1502) and enhancing yield starts with a prerouting step (152) that routes adjacent transistors using diffusion wiring (1506), routes power and ground nets (1508), routes aligned gates (1510), routes all remaining aligned source/drain nets as well as any special nets (1512). Next, all of the remaining nets are routed using an area based router (1408). Nets are order based on time criticality or net topology (1602). A routing grid is assigned for all the layers to be used in routing (1604). An initial coarse routing is performed (1606). Wire groups are assigned to routing layers (1608). Routing is improved and vias are minimized (1610). A determination is then made whether the routing solution is acceptable (1612). If the routintg solution is not acceptable, the routing space is expanded and routing costs and via costs are modifyied to improve the routing solution. Finally, the best routing solution is picked (1414).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.