Method and apparatus for providing erasing and programming protection for electrically erasable programmable read only memory
US5890191A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 10, 1996 |
| Grant date | Mar 30, 1999 |
| Priority date | — |
| Expiry date | May 10, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/22
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Method and apparatus for providing erasing and programming protection of an EEPROM (22) to significantly reduce the possibility of unintentional erasing or programming of the EEPROM (22). In one embodiment, a read access of a block protect value (111) is a requirement for enabling the EEPROM charge pump (78). The block protect value (111) may be located in the EEPROM array (22) itself. In one embodiment, an externally provided signal (24) must be provided to an integrated circuit (10) in order to enable a write access to modify the block protect value (111). In one embodiment, a charge pump enable value (103) is provided to enable or disable operation of the charge pump (78). Thus, a combination of hardware and software protection is provided for an EEPROM (22), including protection for enabling of a charge pump (78).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.