"Marcelo" <[EMAIL PROTECTED]> wrote in message
news:38248@palm-dev-forum...
>
> I know that we can write over the flash memory around 10.000 times, so if
i
> do a loop for more than 10000, what�s up with the flash memory?

Flash memory usually works similar to EPROMs, but with much a purely
electrical way to reset the cells back to their "erased" state.  (EPROMs use
ultraviolet light to reset the memory).  A flash programming routine will
hit the flash memory the right way to put the internal state machine into
program mode, then go and send bits into memory until the change becomes
permanent.  Depending on the flash process, erased memory is either all 0's
or all 1's.  You program the memory by changing some of those bits to the
other state.  It is usually impossible to change the bits back to their
erased state without clearing out the entire memory sector -- the sector
size varies from flash device to device.

The usual failure mode is that after so many write/erase cycles, some of the
bits will not return to the clear state.  That means that there will be
memory cells that are stuck with a bits on or off.  The other failure
possibility is that you'll have cells which will be stuck as erased, without
the ability to be programmed out of erase mode.

--
Ben Combee
Veriprise Wireless <http://www.veriprise.com>



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