Semiconductor memory device
US7184351B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 2005 |
| Grant date | Feb 27, 2007 |
| Priority date | — |
| Expiry date | Aug 17, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C2211/4067
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A semiconductor memory device including an on-chip ECC circuit and having a data retention mode which includes, in the order of state transition, an encoding state EEST by an error correction circuit in which the error correction circuit carries out calculation of parity bits of data of the memory cells, a burst self-refresh state BSST in which the memory cells are self-refreshed in a burst with a period shorter than in ordinary self-refresh, a power-off state PFST in which an internal power supply circuit is partially turned off, a power-on state PNST in which the internal power supply circuit, partially turned off, is turned on, and a decoding state EDST by the error correction circuit in which the error correction circuit corrects errors of the memory cells. In case a command for exiting from the data retention mode in the encoding state, transition may be made to an idle state IST so that re-entry may be made from the decoding state EDST to the BSST.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.