基于哈希表的高效存储器内建自修复方法

An Efficient Memory Built-in Self-Repair Method Based on Hash Table

现有存储器内建自修复方法要么遍历式地址比较效率低,要么并行地址比较功耗高,都不适用于大故障数存储器.对此,本文提出一种高效的存储器内建自修复方法,该方法对占故障主体的单元故障地址以哈希表形式进行存储,以利用哈希表的快速搜索特性提升地址比较效率.本文方法修复后的存储器在1个时钟周期内即可完成地址比较,修复后存储器性能不受任何影响,与目前广泛采用的基于CAM的方法处于同一水平,但功耗方面却具有明显优势.计算机模拟实验表明,对于512×512×8bits的存储器在同等冗余开销的情况下本文方法修复率相对于ESP方法平均提高了32.25%.

Existing built-in self-repair（BISR） methods are either inefficient using traversal address compare or high power consumption using parallel address compare.Neither is suitable for memories with large fault quantity.In order to solve this issue,an efficient memory BISR method based on hash table is proposed.In the proposed method cell fault addresses which contribute the main part of memory faults were stored in the form of a hash table.With quick search feature of hash table the proposed method improves address compare efficiency radically.Under work mode address compare process can be finished within 1 clock cycle,and this will ensure repaired memory against additional performance penalty.The proposed method achieves the same address compare efficiency to CAM based method with much lower power consumption.Experimental results show that for 512×512×8 bits memory the proposed method achieves 32.25% repair rate increment on average to ESP method with the same redundancy overhead.