Detailed placement with search and repair
US8984464B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 2012 |
| Grant date | Mar 17, 2015 |
| Priority date | — |
| Expiry date | Nov 19, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2119/12
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method of detailed placement for ICs is provided. The method receives an initial placement and iteratively builds sets of constraints for placement of different groups of cells in the IC design and uses a satisfiability solver to resolve placement violations. In some embodiments, the constraints include mathematical expressions that express timing requirements. The method in some embodiments converts the mathematical expressions into Boolean clauses and sends the clauses to a satisfiability solver that is only capable of solving Boolean clauses. In some embodiments, the method groups several cells in the user design and several sites on the IC fabric and uses the satisfiability solver to resolve all placement issues in the group. The satisfiability solver informs placer after each cell is moved to a different site. The method then dynamically builds more constraints based on the new cell placement and sends the constraints to the satisfiability solver.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.