Well, the determined thief needs BOTH time and (money or equipment).  One would
require a very powerful microscope with some sort of alpha bombardment device
(or very, very, very tiny probes).  In other words, only a chip fabrication
plant would have the resources to perform this kind of operation.

However, the cost to do so, even with the right equipment, would be very high.
High enough that it would be cheaper for someone to hire a programmer and
duplicate your functionality.  The only thing you might be protecting in your
chip which they may not be able to duplicate are keys or passwords.  But give
enough time, they could probably determine reasonable approximations such that
they could replace your chip with theirs.  This is also the best legal route to
go.

So, in other words, you need to weigh your need for code protection and what
lengths you need to go to for protection, over their need to make your chip
cheaper by burning their own.

Again, use the right tool for the right job.  It appears that your two top
prioritys are code protection and flash upgradability.  You cannot achieve both
completely in the PIC.  The best you can do is a reasonable approximation.  As
indicated above, the ONLY part of a PIC program which cannot be eaily duplicated
by a good programmer are keys and passwords.  Those, hopefully are either not be
used, or not going to change.  If you aren't using them, then there is no big
reason to code protect your chip, all it does it force someone to program a
reasonable approximation of what you're doing, rather than an exact copy.

So, yes, you may as well surrender one to the other if you are heck bent on
using a 16f8xx.

-Adam

anonlistpost anonlistpost wrote:
> If one can erase the code protect, than it stands to reason chip recalls
> with 100% code protect are futile.  And best to just use flash for flash and
> only try and use code protection to dissuade the ambivalent.  The determined
> thief, it appears, can aways expose the die and get at your code by erasing
> the bits.  Is this a real possibility?
>
> Shall I surrender to defeat on this and just use flash and leave my code
> naked??

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