Method for capturing digital data in an automatic test system
US5938780A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 19, 1997 |
| Grant date | Aug 17, 1999 |
| Priority date | — |
| Expiry date | Sep 19, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/31937
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for operating automatic test equipment for capturing digital data produced by a semiconductor device under test, whereby the digital data is repetitively sampled to produce a series of sampled data pairs. The digital data and the sampling frequency can be non-coherent. As a result, the digital data can be sampled early relative to some bits and late relative to other bits. The sampled data pairs that are captured while these shifts take place, from early-to-late sampling or from late-to-early sampling, are then assigned to respective groups. A minimum number of bit patterns, corresponding to the sampled digital data, is then derived from contiguous groups of sampled data pairs, and compared with expected bit patterns. The method is especially useful for capturing digital data with drifting frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.