ECC design for fault-tolerant crossbar memories: A case study

Crossbar memories are promising memory technologies for future data storage. Although the memories offer trillion-capacity of data storage at low cost, they are expected to suffer from high defect densities and fault rates impacting their reliability. Error correction codes (ECCs), e.g., Redundant Residue Number System (RRNS) and Reed Solomon (RS) have been proposed to improve the reliability of memory systems. Yet, the implementation of the ECCs was usually done at software level, which incurs high cost. This paper analyzes ECC design for fault-tolerant crossbar memories. Both RS and RRNS codes are implemented and experimentally compared in terms of their area overhead, speed and error correction capability. The results show that the encoder and decoder of RS requires 7.5× smaller area overhead and operates 8.4× faster as compared to RRNS. Both ECCs has fairly similar error correction capability.