Method and apparatus for retaining flash block structure data during erase operations in a flash EEPROM memory array
US5581723A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 1993 |
| Grant date | Dec 3, 1996 |
| Priority date | — |
| Expiry date | Feb 19, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/1435
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for reliably storing management data in a flash EEPROM memory array, which array is divided into a plurality of individually-erasable blocks of memory cells and in which each of the blocks of memory cells has stored thereon data regarding management of the array during a cleanup process in which valid data stored in a first block is written to another block of the array, and then the first block is erased. The process includes the steps of storing data regarding management of the array from the first block in random access memory and, in an enhanced process, on another block before erasure of the first block. The data may then be rewritten to the first block after the erase. With the enhanced process, a special identification is provided to the data regarding the management of the array stored on another block which is outside the normal identification range for the host computer so that the specially identified data is not lost during a power loss during an erase process and may be detected after power is restored to the system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.