Lpc2000

--- In lpc2000@yahoogroups.com, Robert Wood <robert.wood@a...> wrote:
>
> I am no expert on this, but I am lead to believe writing file 
systems
> for flash based storage systems is a tricky business if you want to
> get maximum life out of your flash. Apparently, you need to try and
> ensure that you write and erase sectors evenly, not just write to
> whatever space might be free.
> 
> As far as I understand, the physics of how flash works means that if 
you
> don't watch how you write to the memory, over a period of time - not
> only can you wear out the cells you are writing to, but adjacent 
ones as
> well.
> 
> This company:
> 
> http://www.hcc-embedded.com/site.php
> 
> do a very neat, very small footprint flash file system for various
> embedded processors - including ARM IIRC. More than $150, but if 
what
> they say is true (and I  suspect it is) you will hugely increase the
> life of your flash cards.
> 
> Cheers,
> 
> Rob
>
The key phrase here is 'wear leveling' basically you need to add a 
flash-access sublayer that implements this. The best way to implement 
this technology is to add the flash-access sublayer, and to write a 
driver that makes this sublayer emulate an IDE hard drive. Then 
everything works really-really well! I currently have implemented this 
type of technology on a broad range of products using an off-the-shelf 
FAT16 file system interfaced to an IDE interface to a soldered-on 
FLASH array using Intel Strata-flash or the Spansion chips.

Ken Wada