Heating Dispersal for Self Self-Healing Healing NAND Flash Memory
Abstract: Substantially reduced lifetimes are becoming a critical issue in NAND flash memory with the advent of multi multi-level cell and triple-level level cell flash memory. Researchers discovered that heating can cause worn worn-out out NAND flash cells to become reusable and greatl greatlyy extend the lifetime of flash memory cells. However, the heating process consumes a substantial amount of power, and some fundamental changes are required for existing NAND flash management techniques. In particular, all existing wear wear-leveling techniques are based on the principle of evenly distributing writes and erases. For self self-healing healing NAND flash, this may cause NAND flash cells to be worn out in a short period of time. Moreover, frequently healing these cells may drain the energy quickly in battery-driven battery mobile devices, which is defined as the concentrated heating problem. In this paper, we propose a novel wear wear-leveling leveling scheme called DHeating (Dispersed Heating) to address the problem. In DHeating, rather than evenly distributing writes and erases over a time period, write and erase operations are scheduled on a small number of flash memory cells at a time, so that these cells can be worn out and healed much earlier than other cells. In this way, we can avoid quick energy depletion caused by concentrate concentrated d heating. In addition, the heating process takes several seconds and has become the new performance bottleneck. In order to address this issue, we propose a lazy heating repair scheme. The lazy heating repair scheme can ease the long time delays caused by the heating via