Apparatus and method for programming multistate memory device
US5768287A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1996 |
| Grant date | Jun 16, 1998 |
| Priority date | — |
| Expiry date | Oct 24, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C2211/5621
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An apparatus and method for programming the memory cells of a multistate memory. The method involves the collapsing of data before transmitting to the memory cells. A controller generates optimized program pulses of high voltage to apply to the memory cells. The pulses vary in amplitude and time, depending on the state level being transitioned. Program verify is performed by reading the programmed data back into the controller where it is compared with the original value intended for programming. This compare operation modifies the data read and initial data to reflect which memory cells require further programming. The modified data is again collapsed and sent to the memory for further programming and verify cycles until a monitoring circuit within the controller detects that no further programming is required.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.