Apparatus and method for detecting defective NVRAM cells
US6256755A · kind A · utility
13Cited by
13References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 19, 1998 |
| Grant date | Jul 3, 2001 |
| Priority date | — |
| Expiry date | Oct 19, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/04
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An apparatus and method for detecting a defective array of NVRAM cells. A counter is provided which times an erase time interval for the NVRAM cells during a regular erase function. The computed erase interval is compared with a maximum erase interval to determine at least a first characteristic which indicates the block of NVRAMs is at the end of its useful life. A second characteristic is determined by computing the slope in the erase time function versus the number of simulated erase functions. When the slope of the erase function exceeds a maximum slope, the NVRAM array is determined to be at the end of its useful life.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.