Anyone else tried this? Good/bad?

I have a project with a PIC24 that is using the self programming of flash t=
o store some non-volatile data including a slow count - up time in minute i=
ncrements. The counter is part of a larger structure of NV data.

I want to avoid rewriting the whole block each time the counter is updated =
and came up with the following.

Flash when erased reads all ones. Writing changes ones to zeros. Overwritin=
g can happen but only to change ones to zeros (I assume the PIC flash behav=
es like other NOR flash in this regard). By setting aside a byte or two as =
a counter, each count could be represented as a zeroed bit, each bit zeroed=
 being an increment. When all are zeroed, a real counter is updated with th=
e number of bits at zero and the process can start over. As a further enhan=
cement, each time the block is written for an update of something else, the=
 counter would be updated from the bit count and the bit counter erased to =
go again.



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