On Fri, Jan 23, 2004 at 09:59:09AM -0500, J.C. Wren wrote:
> Be aware that FAT is an extremely poor format for MMC if you plan to do
> much writing. Compact flash cards have automagic wear leveling
> algorithms that prevent premature wearing of sectors. MMC has no such
> facility.
MMC does have wear leveling.
This is from MMCProdMn_5.1.pdf (sandisk), page 1-4:
"MultiMediaCards do a read after write under margin conditions to verify
that the data is written correctly. In the rare case that a bit is found to
be defective, MultiMediaCards replace this bad bit with a spare bit within
the sector header. If necessary, MultiMediaCards will even replace the
entire sector with a spare sector. This is completely transparent to the
host and does not consume any user data space."
So FAT is not problem. The (older) smartmedia card does not have wear
leveling.
Matthias
