Method of overwriting data in nonvolatile memory and a control apparatus used for the method
US6851015B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 20, 2002 |
| Grant date | Feb 1, 2005 |
| Priority date | — |
| Expiry date | Dec 12, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/102
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a nonvolatile memory such as flash memory where data is stored sector by sector, a method of overwriting a data sector is provided. The old data to be overwritten in a data sector along with its error detection code are initially saved to a backup region which is also in a non-volatile area. The old data in the data sector is then erased and new data along with its own error detection code are written into the same data sector where the old data was previously stored. When a power outage occurs during the overwrite process, error checking is performed to determine whether the data in the data sector is valid using the associated error detection code. Because the old data is saved in a non-volatile area, even if such unexpected power outage occurs during the overwrite process and the data in the data sector is determined to be invalid, at least the old data can be recovered from the non-volatile backup region which is not affected by the power outage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.