Using constraints in design verification
US7421669B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 2005 |
| Grant date | Sep 2, 2008 |
| Priority date | — |
| Expiry date | Nov 20, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F30/3323
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for generating a constraint for use in the verification of an integrated circuit design includes identifying a target in a netlist (N) of the design and creating an overapproximate abstraction (N′) of the netlist. A space state (S′) is created by enumerating the states of N′ from which the identified target may be asserted. A constraint space C′ is then derived from the state space S′, where C′ is the logical complement of S′. The process is repeated for multiple selected targets and the constraint spaces from each iteration are logically ANDed. Creating an overapproximate abstraction may include replacing a sequential gate with a random gate. Identifying a sequential gate may include selecting a target in the netlist, performing underapproximate verification of the target, and, if a spurious failure occurs, selecting a gate further down the fanin chain of the currently selected gate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.