Block-erasable non-volatile semiconductor memory which tracks and stores the total number of write/erase cycles for each block
US5544356A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 3, 1995 |
| Grant date | Aug 6, 1996 |
| Priority date | — |
| Expiry date | Mar 3, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2212/7211
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A non-volatile semiconductor memory that is erasable only in blocks is described. Each bit of the non-volatile semiconductor memory cannot be overwritten from a first logical state to a second logical state without a prior erasure. Each bit of the non-volatile semiconductor memory can be overwritten from a second logical state to a first logical state without a prior erasure. The non-volatile semiconductor memory comprises an active block for storing a first file, a reserve block for storing a second file, and a directory block. The second file is a copy of the first file. The copy is made during a clean-up operation prior to erasure of the active block. The directory block comprises a directory entry for identifying the first file.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.