Method and apparatus for random stimulus generation
US6553531B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1999 |
| Grant date | Apr 22, 2003 |
| Priority date | — |
| Expiry date | Jun 24, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/318342
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention adds capabilities to a Hardware Verification Language (HVL) which facilitate the generation of random test data. Sources of random numbers are easily produced by simply adding a randomness attribute to a variable declaration of a class definition. Such variables are called random variables. A “randomize” method call may be made to an instance of the class definition to produce random values for each random variable. The values assigned to random variables are controlled using constraint blocks, which are part of the class definition. A constraint block is comprised of constraint expressions. The constraint expressions may impose a linear ordering in which random variable values must be assigned and this dependency is expressed by directed acyclic graphs (DAGs). The constraint expressions constraining each random variable are converted into ranges of permissible values from which a value is chosen at random. Rather than selecting a value for each random variable from within one of its ranges, as done for the randomize method, each boundary method call sequentially selects a combination of boundary values, for each random variable, from each random v…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.