Write protection security for memory device
US5363334A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 10, 1993 |
| Grant date | Nov 8, 1994 |
| Priority date | — |
| Expiry date | Apr 10, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C7/24
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An erasable programmable memory device has a number of contiguous data storage cells forming the data memory of the device. The address of one of these data storage cells is stored to designate it as a cell which is to be write protected so that its contents may not thereafter be erased or overwritten. Information is also stored to identify the total number of contiguous data storage cells to be similarly write protected commencing with the cell whose address is stored to designate write protection. The contents of the designated and identified cells are then made permanent. Write protection of the designated and identified cells is accomplished by comparing each write operation address with the addresses of the data storage cells encompassed within the protected area, and if it is within that area, aborting the write operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.