Nonvolatile semiconductor memory device
US8369151B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 2010 |
| Grant date | Feb 5, 2013 |
| Priority date | — |
| Expiry date | Aug 3, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C2213/72
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
According to one embodiment, a nonvolatile semiconductor memory device includes a memory cell array including regular memory cells and permanent memory cells and a control circuit. The regular memory cells are capable of switching between a first data storage state and a second data storage state. The permanent memory cells are fixed in a third data storage state that is read as the same logic level data as the first storage state. Data is stored in at least one of the regular memory cells and at least one of the permanent memory cells. The control circuit rewrites at least one of the regular memory cells from the second data storage state to the first data storage state at the time of data holding. The control circuit performs a reading operation after rewriting the regular memory cells from the first data storage state to the second data storage state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.