TLC-FTL: Workload-aware Flash Translation Layer for TLC/SLC Dual-Mode Flash Memory in Embedded Systems

Similar to traditional NAND flash memory, triple-level cell (TLC) flash memory is used as secondary storage to meet the fast growing demands on storage capacity. TLC flash memory exhibits attractive features such as shock resistance, high density, low cost, non-volatility and low access latency natures. However, TLC flash memory also has some extra limitations, such as write disturbance, low performances and very limited cycles compared to single-level cell (SLC) flash memory. In this paper, we propose a workload-aware flash translation layer, named TLC-FTL, for the TLC/SLC dual-mode enabled flash memory, to improve performance and lifespan of the system. The basic idea is to classify metadata/userdata according to their access pattern, and store the hot/code data in SLC/TLC-mode flash, respectively. TLC-FTL dynamically allocates TLC/SLC capacity based on different workloads. Experimental results show that TLC-FTL can effectively improve the performance and lifetime of the TLC/SLC dual-mode flash memory in embedded systems.