> > > Capacitors on the supply provide me with some > milliseconds to repond > to > > > power failure, which I would > > > like to use to do as much cleanup as possible before power is > > > totally gone. In particular, I am concerned > >
>What I've seen is marketing bullet points saying the cards can survive a power loss event with no loss of data, but when I read the >detailed CF specification, the disclaimer was that power had to be held up for X mSec (I forgot what X was, 2mSec or 10mSec most >likely) after the last write operation. The marketing bullet point was exactly that: marketing. The real requirement levied on the user >(you) was that you had to have X mSec power hold up after the last write operation (i.e. a X mSec power fail warning with no write >operations after the PF warning). The hold-up requirement gave the CF internals enough time to complete a flash write cycle. One simple use for the power fail interrupt would be to just turn off interrupts and loop until power fail. This would insure that a write or erase operation completed fully. P.S. Don't forget to cover the situation where power comes back rather than going all the way down! Mark Chambers wvcomputronics.com
