Write protection circuit for use with an electrically alterable non-volatile memory card
US5226006A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1991 |
| Grant date | Jul 6, 1993 |
| Priority date | — |
| Expiry date | May 15, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C7/24
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In the present invention a write protection circuit capable of being used in a memory card is disclosed. The write protection circuit receives an externally supplied write protect signal and generates a protection signal for use with an associated electrically alterable non-volatile memory. The write protection circuit has two non-volatile storage registers, each storing a single bit. Logic means receives a bit from a first register and passes the externally supplied write protect signal as the internally generated protection signal when the bit is in a "1" state. When the bit is in another state, the signal from the second register is used as the protection signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.