Proceedings of the 42nd IEEE/IFIP Int'l Conference on Dependable Systems and Networks (DSN), pp. xx~yy, Boston, MA, June 2012.
With their potential for high scalability and density, resistive memories are foreseen as a promising technology that overcomes the physical limitations confronted by charge-based DRAM and flash memory. Yet, a main burden towards the successful adoption and commercialization of resistive memories is their low cell reliability caused by process variation and limited write endurance. Typically, faulty and worn-out cells are permanently stuck at either `0' or `1'. To overcome the challenge, a robust error correction scheme that can recover from many hard faults is required. In this paper, we propose and evaluate RDIS, a novel scheme to efficiently tolerate memory stuck-at-faults. RDIS allows for the correct retrieval of data by recursively determining and efficiently keeping track of the positions of the bits that are stuck at a value different from the ones that are written, and then, at read time, by inverting the values read from those positions. RDIS is characterized by a very low probability of failure that increases slowly with the relative increase in the number of faults. Moreover, RDIS tolerates many more faults than the best existing scheme---by up to 95% on average at the same overhead level.