Hello Ron, I screwed up the last post, it did not have the [PIC]: tag in the
subject.  Maybe we shouldn't do the replies here?  I think no one would see
it?

-----Original Message-----
From: pic microcontroller discussion list
[mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of Ron Wilder
Sent: Tuesday, July 17, 2001 3:25 PM
To: PICLIST@MITVMA.MIT.EDU
Subject: Re: Who else uses the 16F877?


Maybe you could put in a critical table in the 256 byte area...  A table
that is
accessed at certain times and turns off the system at a four,  six, or
twelve month
interval.  If someone copies your code they won't find it for six months...
well into
their release to customers...  Could cause them many problems trying to
debug that
one.  In the mean time, you could be doing enhancements that continue to
work!  You
just have be more creative than Microchip!  Hope this helps.
Keep smiling,
Ron


Ron Anthony wrote:

> Hello all, who else uses the 16F877?  Who else is totally disgusted that
the
> 77A revision is delayed until next March at the earliest???  The 77 is a
> flash chip that if you leave it flash upgradable, you must leave it
> completely NAKED for copying.  Is this as ridiculous as I think it is?  If
> you code protect the flash it becomes OTP memory that can never be updated
> without wiping out the entire chip, which means your bootloader code is
GONE
> and can't be used to update the flash.
>
> Your options are:
>
> 1.      leave the chip 100% naked and copyable, downloadable, and 100%
reverse
> engineer-able
> 2.      code protect 50% of the ram, making that half OTP style memory,
you can't
> use a bootloader on it, and the other half is still naked
> 3.      protect only 256 bytes, which prevents whole chip copying, but all
that
> is missing is 256 bytes from someone's downloaded code, leaving them only
> 256 bytes to recreate.
>
> None of these options are good.  The 77A revision is much more secure.
You
> can, supposedly, disable in circuit serial programming, and can also
disable
> interal flash reads.  The chip is secure, the only liability being someone
> watching your comms when you update by way of the bootloader.  But, this
can
> be solved with encryption algorithms that decode the flash update after
> getting blocks of data into the chip where it can't be watched.
>
> Microchip has the last 2 years to get out the 77A revision.  What the heck
> is taking this multi-billion dollar company from getting this chip out?
Do
> they have no respect whatsoever for the very code that runs in their chip?
> Most times that's the only non-commodity part of a device!!!!!
>
> Who else is utterly disappointed about this?  Now I have the tortured
> decision to make on a very large production run.  Should I leave the chip
> naked and throw caution to the wind?  Should I code protect half the chip
> with what code can be reasonably considered "stable" ???  Or should I
leave
> the whole chip naked but for the 256 bytes they allow?  Not hard to get
> around that, having everything but 256 bytes.
>
> Any thoughts?  Advise?  Words of wisdom????
>
> Thanks All.
> Ron Anthony, a very disappointed buyer
>
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