Semiconductor memory device having a refresh cycle changing circuit
US7742356B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 2007 |
| Grant date | Jun 22, 2010 |
| Priority date | — |
| Expiry date | Feb 24, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C11/40615
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A semiconductor memory device includes a first refresh cycle changing circuit that changes a refresh cycle according to an auto-refresh mode, without giving influence to a refresh cycle according to a self-refresh mode, and a second refresh cycle changing circuit that changes a refresh cycle according to the self-refresh mode, without giving influence to a refresh cycle according to the auto-refresh mode. In this way, according to the present invention, the refresh cycle according to the auto-refresh mode and the refresh cycle according to the self-refresh mode can be controlled independently. Therefore, refresh operation considering the characteristic of each mode can be executed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.