Enabling Accurate and Practical Online Flash Channel Modeling for Modern MLC NAND Flash Memory.

NAND flash memory is a widely used storage medium that can be treated as a noisy channel. Each flash memory cell stores data as the threshold voltage of a floating gate transistor. The threshold voltage can shift as a result of various types of circuit-level noise, introducing errors when data are read from the channel and ultimately reducing flash lifetime. An accurate model of the threshold voltage distribution across flash cells can enable mechanisms within the flash controller that improve channel reliability and device lifetime. Unfortunately, existing threshold voltage distribution models are either not accurate enough or have high computational complexity, which makes them unsuitable for online implementation within the controller.