Hardware security device for magnetic memory cells
US7224634B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 2003 |
| Grant date | May 29, 2007 |
| Priority date | — |
| Expiry date | Jan 4, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
The present invention provides a special structure of magnetic elements, e.g. MRAM elements, as a security device for IC's containing magnetic memory cells. In an example embodiment, the structure may comprise a combination of two or more associated magnetic elements with pre-set anti-parallel magnetization directions. By determining the polarisation directions of the magnetic elements, exposure to an external magnetic field can be detected. Inverse polarisation directions indicate a normal situation, aligned polarisation directions indicate that the MRAM-array has been exposed to an external field. In this way it can be detected whether a user has tried to erase or alter the data stored in the MRAM in an illegal way. The IC can regularly check the resistance of the security system during operation. Upon detection of a field exposure, the IC can erase all MRAM data, reset itself or, block its functioning.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.