Diagnosis and repair of memory with coupling faults

The problem of diagnosis and spare allocation for a random access memory (RAM) with coupling faults, utilizing spare rows and columns, is examined. It is shown that a coupling fault is repaired if its coupling cell is replaced by a spare row or its coupled cell is replaced by a spare row or column. By specifying both the coupled cell and coupling cell the amount of redundancy required to repair a given set of faults can be reduced. A diagnosis procedure is provided to locate stuck-at faults as well as coupling faults. A graph model is used to describe the repair of coupling faults, and a repair procedure is implemented to allocate rows and columns for repair.<>