Handling power failure - MPC5200

[Wolfgang Denk]

In message <007d01c4c37e$17e8e0d0$0301a8c0 at chuck2> you wrote:
>
> So maybe, are you thinking that a power fail interrupt is a waste of
> time?  Just segment the file system as you suggested and trust the
> writeable part to jffs2?

A PF interrupt can be extremely useful - if it leaves you enough time
to do the things you want to  do.  If  all  you  got  is  50  or  100
milliseconfs  then you have little chance to avoid problems with a CF
card that is being written to. In such a case you  must  design  your
system such that it is robust enough even without such cleanup.

> Another technique that has fallen out of favor but is still useful in some
> applications is battery backed RAM.  It's relatively expensive, but if
> you want fast non-volatile memory it can't be beat.

It depends. Sometimes you may have a  battery,  and  the  power  fail
signal  is  just a warning that leaves you enough time for an orderly
shutdown.

Best regards,

Wolfgang Denk

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