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.