Lpc2000

The end answer to your question is no, you do not need to implement this 
yourself, unless you really plan on hammering the card.  Most SD cards 
these days have between 10,000 to 100,000 write cycles per sector.  For 
example, assuming 100,000 cycles, if you updated a sector once per minute, 
24 hours a day, you would exceed the rated life after 70 days.  However if 
you wrote once per 10 minutes, you'd get 2 years out of it.  As long as you 
don't use Flash like RAM I don't see why you'd need to write that often.

Kingston cards seem to incorporate a built in wear levelling mechanism, and 
also bad block remapping facility, by reserving sectors similar to how a 
hard drive does it.  SanDisk's SD manual states that on their devices the 
wear level command is equivalent to a NOP, since they have > 100,000 
cycles.  That information is from around 2003, so I assume it's still accurate.

-- Sean

At 09:33 PM 1/4/2006, you wrote:
>I read the application note, I have just a question:
>- SD and MMC implement a wear level mechanism or have I to provide a
>wear leveling algorithm by myself?
>Best regards.