Method and apparatus for writing an erasable non-volatile memory
US6075727A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 1998 |
| Grant date | Jun 13, 2000 |
| Priority date | — |
| Expiry date | Jul 29, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C16/10
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method for writing to a bit of a non-volatile memory (50) by alternately applying programming and erase voltages to a control gate wordline of a memory cell. A write includes programming and erasing bits (30, 31, . . . , 32, 33) in the memory array (56). Upon completion of the write operation a verify erase (VE) indication and a verify program (VP) indication are provided to a memory controller (58), which then determines if multiple cycles are necessary. The configuration of the memory cell allows isolation of each bit in the memory array to avoid effects of writes to neighbor bits. According to one embodiment, a three transistor EEPROM is written by providing a high voltage to the drain select of the selected wordline, while providing a low voltage to the drain select of other wordlines. Programming and erase voltages are applied to the control gate wordline of the selected wordline in cycles until the write is complete.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.