Flash memory protection attribute status bits held in a flash memory array
US5930826A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1997 |
| Grant date | Jul 27, 1999 |
| Priority date | — |
| Expiry date | Apr 7, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/22
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Flash memory circuits provide sector protection or file protection with protection attribute status bits held in a flash memory array. The sector protection protects memory data based on the physical location of the data. The flash memory array is divided into a number of memory sectors. Each memory sector can be protected independently. The size of the memory sector is flexible and may be as large as the whole memory array or as small as a single bit group. Each memory sector has protection bits stored in a protection bit array for indicating the protection state of the sector. A parallel protection structure providing both sector protection and block protection is also included. The parallel protection allows small size data protection as well as large size block protection. File protection protects memory data on a file basis regardless of the physical location of the data. Each file has protection bits stored in an attribute memory for indicating the protection state of the file. The attribute memory is made from part of the flash memory which simplifies the process of manufacturing the memory. It also reduces the area size of the attribute memory and the complexity of the cont…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.