Semiconductor memory device and method for its test
US6590815B2 · kind B2 · utility
Assignees
Inventor
Key dates
| Filing date | Oct 12, 2001 |
| Grant date | Jul 8, 2003 |
| Priority date | — |
| Expiry date | Oct 12, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C2029/0403
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A semiconductor memory device and method for its test is disclosed including a CBR (CAS before RAS) refresh test achieved by inputting a CBR command for every redundant word line to be selected. In this way, redundant word lines may be selected without repetition until all of the redundant word lines have been selected. By doing so, an accurate determination of the refresh period may be obtained. A CBR refresh counter (15) may be activated every time a control signal is received when a refresh test on redundant memory cells (RC) is performed. Redundant counter signals (RCNT0 to RCNT5) may be applied to a X address buffer (2A). X address buffer (2A) may select the redundant counter signals (RCNT0 to RCNT5) to sequentially select the redundant word lines (RWL0 to RWL63) when a redundant refresh test is performed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.