Semiconductor memory device having a self-diagnosing function
US4833652A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 1988 |
| Grant date | May 23, 1989 |
| Priority date | — |
| Expiry date | Mar 22, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C29/44
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A defect detection circuit for detecting a defect of a memory cell, a counter for counting defects detected by the defect detect circuit, and a remediableness determination unit for determining whether a count of the counter allows remedy by a redundancy circuit, are provided in a tester for a semiconductor memory or on a memory chip having a redundancy circuit. When the count of the counter is the same as or smaller than the number of at least one of the auxiliary rows and columns of the redundancy circuit, the memory is determined to be "remediable." Otherwise, the memory is determined to be "unremediable." When the count of the counter exceeds the number of at least one of the auxiliary rows and columns of the redundancy circuit, the memory test is interrupted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.