Performance characteristics of flash memory: Model and implications

In this paper, we propose a model to identify the cost of block cleaning of Flash memory. The model defines three performance parameters, namely, utilization, invalidity, and uniformity and presents a formula for estimating the block cleaning cost based on these parameters. Then, we design a new modification-aware (MODA) page allocation scheme which can improve the block cleaning cost by enhancing uniformity of Flash memory. Real implementation experiments conducted on an embedded system show that the MODA scheme can reduce block cleaning time by up to 43 seconds (with an average of 10.2 seconds) compared to the traditional sequential allocation scheme that is used in YAFFS