I
> suppose someone might want to do that. Not many people would go to
the
> trouble and those who would probably can and have.
>
> --
>
> Brian Lloyd Granite Bay Montessori
> brian AT gbmontessori DOT com 9330 Sierra College Blvd.
> +1.916.367.2131 (voice) Roseville, CA 95661, USA
Probably not... With the memory protection bits enabled, it is very
difficult to get at the contents. The basic technique is to grind
away the plastic and try to get at the flash bit states with a high
power microscope. So, the manufacturers add an oxide layer over the
flash with the idea that the hydrofluoric acid used to dissolve the
oxide layer will also destroy the flash. It has been a cat and mouse
game since the earliest microcontrollers.
There have been huge debates in the LPC2000 group about the efficacy
of Philips (now NXP) RP (Code Read Protection) when the device
supports JTAG. One person insists he can get at the contents but
won't disclose how while NXP says no way in the world and most
agree. But the debate rages from time to time.
A key factor in choosing one microcontroller over another is the
matter of code protection. When the boards are manufactured by
outsourced vendors, it is easy for them to make a few
thousand 'extras'. It is best if the code is either not available at
manufacturing or not accessible even if it is available. It's a huge
decision point.
Richard
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