Secure memory management unit for microprocessor
US5825878A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 1996 |
| Grant date | Oct 20, 1998 |
| Priority date | — |
| Expiry date | Sep 20, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F2207/7219
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A secure embedded memory management unit for a microprocessor is used for encrypted instruction and data transfer from an external memory. Physical security is obtained by embedding the direct memory access controller on the same chip with a microprocessor core, an internal memory, and an encryption/decryption logic. Data transfer to and from an external memory takes place between the external memory and the memory controller of the memory management unit. All firmware to and from the external memory is handled on a page-by-page basis. Since all of the processing takes place on buses internal to the chip, detection of clear unencrypted instructions and data is prevented.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.