FREE-p: Protecting non-volatile memory against both hard and soft errors

DH Yoon, N Muralimanohar, J Chang… - 2011 IEEE 17th …, 2011 - ieeexplore.ieee.org
2011 IEEE 17th International Symposium on High Performance …, 2011ieeexplore.ieee.org
Emerging non-volatile memories such as phase-change RAM (PCRAM) offer significant
advantages but suffer from write endurance problems. However, prior solutions are oblivious
to soft errors (recently raised as a potential issue even for PCRAM) and are incompatible
with high-level fault tolerance techniques such as chipkill. To additionally address such
failures requires unnecessarily high costs for techniques that focus singularly on wear-out
tolerance. In this paper, we propose fine-grained remapping with ECC and embedded …
Emerging non-volatile memories such as phase-change RAM (PCRAM) offer significant advantages but suffer from write endurance problems. However, prior solutions are oblivious to soft errors (recently raised as a potential issue even for PCRAM) and are incompatible with high-level fault tolerance techniques such as chipkill. To additionally address such failures requires unnecessarily high costs for techniques that focus singularly on wear-out tolerance. In this paper, we propose fine-grained remapping with ECC and embedded pointers (FREE-p). FREE-p remaps fine-grained worn-out NVRAM blocks without requiring large dedicated storage. We discuss how FREE-p protects against both hard and soft errors and can be extended to chipkill. Further, FREE-p can be implemented purely in the memory controller, avoiding custom NVRAM devices. In addition to these benefits, FREE-p increases NVRAM lifetime by up to 26% over the state-of-the-art even with severe process variation while performance degradation is less than 2% for the initial 7 years.
ieeexplore.ieee.org