Search This Blog

Wednesday, March 25, 2009

M-Systems. Technical Note: TrueFFS Wear-Leveling Mechanism (TN-DOC-017) March 20, 2002

This document provides an overview of the DiskOnChip TrueFFS wear-leveling mechanism and explains why it is required for NAND flash technology.

Dynamic wear leveling – When there are no free physical erase units left in the pool, a process called folding – garbage collection occurs.

FAT filter – When it detects that a cluster has changed status from “allocated” to “free”, the FAT fitler notifies the other layers of the TrueFFS driver that the sectors associated with these clusters should be marked as erased. Utilizing the FAT filter enables more areas of the flash memory to be reclained by TrueFFS, which improves the efficiency of the wear-leveling algorithm.

Static Data Wear-Leveling – The static wear-leveling process performs virtual-unit swapping one time per 256 virtual sector write operations.

No comments:

Post a Comment

Blog Archive