Security circuit for protecting data stored in memory
US5357467A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 27, 1993 |
| Grant date | Oct 18, 1994 |
| Priority date | — |
| Expiry date | Oct 27, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/1408
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A memory stores data, the contents of which must be kept secret. A memory stores security data and a latch circuit latches key data for releasing the security. A comparison circuit compares security data with key data, outputs a coincidence signal when they coincide with each other and outputs a non-coincidence signal when they do not coincide with each other. When a coincidence signal is output from the comparison circuit, an output signal of a change bit control circuit is set to the "0" level and address changing circuits change an address signal for reading out data from the memory according to the security data supplied from the memory.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.