Streamlined write operation for EEPROM system
US5396468A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 1993 |
| Grant date | Mar 7, 1995 |
| Priority date | — |
| Expiry date | Nov 8, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/1008
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
Various optimizing techniques are used for erasing semiconductor electrically erasable programmable read only memories (EEPROM). An erase algorithm accomplishes erasing of a group of memory cells by application of incremental erase pulses. Techniques include a 2-phase verification process interleaving between pulse applications; special handling of a sample of cells within each erasable unit group; defects handling; and adaptive initial erasing voltages. A streamlined write operation on a flash sector of the EEPROM is implemented by employing the optimized erase in an efficient manner. The write operation includes an initial quick erase of the sector followed by programming of data and verification. Only on those infrequent occasions when a failure occurs as manifested during program verification that the optimized erase will need be evoked.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.