Adaptive programming method and apparatus for flash memory analog storage
US6301151A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 9, 2000 |
| Grant date | Oct 9, 2001 |
| Priority date | — |
| Expiry date | Aug 9, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C27/005
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Adaptive programming method and apparatus for flash memory analog storage. The present invention method is to adjust the voltage of the programming pulse each time based on the result of the previous pulse. The expected change in the programmed value is compared to the measured change, and the difference used to improve the model of that cell after each programming pulse. The algorithm is "adaptive" because the voltage of each pulse is adapted to whatever the cell needs. If the cell is programming too slowly, the voltage is increased dramatically to make it faster. Conversely if the results show that a particular cell is programming too fast, the next voltage pulse is increased by only a small amount (or even decreased if necessary). Because the response of the cell is non-linear, a special analog circuit is used to calculate the optimum voltage for each pulse. As one alternative, a digital calculation may also be used to program the cells. Because of the programming speed of the exemplary method, a voice signal may be sampled and stored in flash memory one cell at a time. Variable programming parameters other than voltage may be used if desired.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.