Improved representatives for unrepairability judging and economic repair solutions of memories

This paper introduces a novel procedure of identifying better representatives of faulty cells in a memory map to help judge unrepair ability and provide economic repair recommendation. These representative faulty cells, called leading elements (LE), are classified into four primary types based on their characteristics. Three specific pairs of initially identified LE are extracted for further operations, which are replacing certain LE with other better representatives and assigning the cross point faults between two certain LE as new LE. All steps of the procedure are analyzed in sequence with verification, clearly indicating that the identified LE represent both the more exact thresholds for judging unrepairability and usually the most economic repair solutions. Experiments on many example maps show that the procedure can be fast in searching 7% more LE and be applicable to accumulate data for redundancy planning afterwards