Storage device having testing function and memory testing method
US6490685B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 4, 1998 |
| Grant date | Dec 3, 2002 |
| Priority date | — |
| Expiry date | Dec 4, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C29/08
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A flash memory includes an encoded cryptographic key “k” stored therein. A protected ROM, an external access to which is inhibited, includes a decoding program stored therein to decode the cryptographic key “k”. The cryptographic key “k” is decoded by using the decoding program. With the cryptographic key “k” as decoded, data is encrypted and stored in the flash memory. Data read out from the flash memory is output after decrypted with the cryptographic key “k.” In order to check an area having the decoding program stored therein, data which forms the decoding program is processed by using a hash function stored in the ROM, and a processing result and an expected value are compared with each other. When the processing result and the expected value matches with each other, the aforementioned area is determined as being in a normal condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.