An average update frequency based NAND flash garbage collection algorithm

Abstract

Aiming at the unique properties of NAND flash, an average update frequency based NAND flash garbage collection algorithm is proposed. Firstly, the victim block selection strategy based on invalid page age sum is adopted. Then, based on FaGC and GCbAH algorithm, the proposed algorithm re-defines the heat degree calculation method, and applies average update frequency of logical page to replace fixed threshold as the criterion of cold or hot data. Thus, more accurate determination and separation of cold and hot data are realized. The experimental simulation results show that compared with GR, CB, CAT, FaGC and GCbAH algorithms, the proposed algorithm has achieved a better performance in terms of garbage collection overhead and wear leveling.

Keywords

• NAND flash memory
• wear leveling
• garbage collection
• hot and cold separation
• victim block