Semiconductor memory system with the function of the replacement to the other chips
US5469390A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 1994 |
| Grant date | Nov 21, 1995 |
| Priority date | — |
| Expiry date | Sep 6, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C29/808
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a semiconductor memory system including a plurality of memory chips, a spare memory is shared among the memory chips. For such a purpose, a common redundant circuit and an external terminal capable of accessing to a spare memory are added to a semiconductor memory system, and a first region for storing a defect address in each memory of the semiconductor memory system and a second region for storing a defect address of the system of the object having the same structure as the first region are provided in the redundant circuit. With this, even when the defect of a normal memory of the semiconductor memory system can not be replaced with the spare memory of the system itself, replacement is made possible with other system having the same structure. Accordingly, the yield of the semiconductor memory system can be increased, and the reliability is also increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.