Programming analog memory cells for reduced variance after retention
US7864573B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 23, 2009 |
| Grant date | Jan 4, 2011 |
| Priority date | — |
| Expiry date | Jul 19, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C2211/5621
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method includes defining a nominal level of a physical quantity to be stored in analog memory cells for representing a given data value. The given data value is written to the cells in first and second groups of the cells, which have respective first and second programming responsiveness such that the second responsiveness is different from the first responsiveness, by applying to the cells in the first and second groups respective, different first and second patterns of programming pulses that are selected so as to cause the cells in the first and second groups to store respective levels of the physical quantity that fall respectively in first and second ranges, such that the first range is higher than and the second range is lower than the nominal level. The given data value is read from the cells at a later time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.