Can someone tell me if it's possible to read a PIC that has had it's
protection fuse blown? I've heard there's a way to apply a voltage and
put it into test mode. If I create a programmed chip and protect it, can
someone else come along and copy it? Are there any ways to prevent this
from happening?
>Hello again fellow PIClisters,
>
>Can someone tell me if it's possible to read a PIC that has had it's
>protection fuse blown?
YES
>I've heard there's a way to apply a voltage and put it into test mode.
Not exactly, but I will not tell how it's done.
> If I create a programmed chip and protect it, can someone else come along
and copy it?
YES (see number 1)
Are there any ways to prevent this from happening?
The best (not full proof) way is to zap the program pin with enough voltage
and current to destroy it without blowing up the chip.
sorry the news isn't better, but not being able to protect the code is no
reason for not developing a good product and putting it on the market. i am
much more concerned about someone copying my idea than stealing my code.
>
> >Hello again fellow PIClisters,
> >
> >Can someone tell me if it's possible to read a PIC that has had it's
> >protection fuse blown?
>
> YES
>
> >I've heard there's a way to apply a voltage and put it into test mode.
>
> Not exactly, but I will not tell how it's done.
>
> > If I create a programmed chip and protect it, can someone else come along
> and copy it?
>
> YES (see number 1)
>
> Are there any ways to prevent this from happening?
>
> The best (not full proof) way is to zap the program pin with enough voltage
> and current to destroy it without blowing up the chip.
>
> sorry the news isn't better, but not being able to protect the code is no
> reason for not developing a good product and putting it on the market. i am
> much more concerned about someone copying my idea than stealing my code.
>
> michael
On one circuit I have been working on, the capability to do the job
(controlling HV DC to accomplish this job) in a array of PICs instead of
with a relatively expensive & perishable array of PCs, IS the idea (i.e.
it's easy to do with an expensive array of Pentii, almost impossible to
do with a flock of cheap PICs, but quite cost-effective once you figure
the tricks out.) In that (admittedly rareish) sort of situation, having
the code stolen means the idea's stolen. Tough to protect a PIC, in any
better way than you mention, without resorting to pyrotechnic devices &
etc. (i.e. if you open the case an M-80 blows the chip apart) - Thought
of a good way for this industrial device, though; Have a fairly
powerful spring which is released to smash the chip if someone breaks
into the control box. (Rigged like an old caplock musket or like a
modern rifle striker.) Easy to do that... Putting 220VDC across
Vdd/Vss would do it, too. Expect to replace the parts on your next
service call. <G>
:-) if you grind the chip information off of the top of the I.C.'s you
will creat a HUGE headache for the design copier. Low tech way of slowing
them down.
> Michael S. Hagberg wrote:
> >
> > >Hello again fellow PIClisters,
> > >
> > >Can someone tell me if it's possible to read a PIC that has had it's
> > >protection fuse blown?
> >
> > YES
> >
> > >I've heard there's a way to apply a voltage and put it into test mode.
> >
> > Not exactly, but I will not tell how it's done.
> >
> > > If I create a programmed chip and protect it, can someone else come along
> > and copy it?
> >
> > YES (see number 1)
> >
> > Are there any ways to prevent this from happening?
> >
> > The best (not full proof) way is to zap the program pin with enough voltage
> > and current to destroy it without blowing up the chip.
> >
> > sorry the news isn't better, but not being able to protect the code is no
> > reason for not developing a good product and putting it on the market. i am
> > much more concerned about someone copying my idea than stealing my code.
> >
> > michael
>
> On one circuit I have been working on, the capability to do the job
> (controlling HV DC to accomplish this job) in a array of PICs instead of
> with a relatively expensive & perishable array of PCs, IS the idea (i.e.
> it's easy to do with an expensive array of Pentii, almost impossible to
> do with a flock of cheap PICs, but quite cost-effective once you figure
> the tricks out.) In that (admittedly rareish) sort of situation, having
> the code stolen means the idea's stolen. Tough to protect a PIC, in any
> better way than you mention, without resorting to pyrotechnic devices &
> etc. (i.e. if you open the case an M-80 blows the chip apart) - Thought
> of a good way for this industrial device, though; Have a fairly
> powerful spring which is released to smash the chip if someone breaks
> into the control box. (Rigged like an old caplock musket or like a
> modern rifle striker.) Easy to do that... Putting 220VDC across
> Vdd/Vss would do it, too. Expect to replace the parts on your next
> service call. <G>
>
> Mark Willis, .....mwillisKILLspam@spam@nwlink.com
>
>:-) if you grind the chip information off of the top of the I.C.'s you
>will creat a HUGE headache for the design copier. Low tech way of slowing
>them down.
>
nope. once you trace power, ground, xtal, and i/o it's not hard to figure
out which processor family you're dealing with.
at first: I does not warrant any information below and for consecuently
damages, lost profits etc. (the usual stuff). I am not responsible for
change in goodwills of any third parties.
I have heard, that the PIC16C84 can be read with a high level of
probability if you rise suddenly the programming voltage. It was always
denied officially from the appropriate persons (I won't say the name of
them.) However, as these rumours has been widespread, the 16C84 has been
declared as obsolete, and the 16F84 replaced it. I have not heard that any
of other PICs can be read if code protection set (it does not means they
can't). For the sake of security, I do not use PIC16C84 in any of my
applications if the code should be protected.
To violate the chip (remove the cover of the package, reset the code
protection fuse manually under microscope or whatever, and get the code)
is another story. There was former an ad of a firm offering such service
in the PIClist. The opinions differ.
> >Hello again fellow PIClisters,
> >
> >Can someone tell me if it's possible to read a PIC that has had it's
> >protection fuse blown?
>
> YES
>
> >I've heard there's a way to apply a voltage and put it into test mode.
>
> Not exactly, but I will not tell how it's done.
>
> > If I create a programmed chip and protect it, can someone else come along
> and copy it?
>
> YES (see number 1)
>
> Are there any ways to prevent this from happening?
>
> The best (not full proof) way is to zap the program pin with enough voltage
> and current to destroy it without blowing up the chip.
>
>
> sorry the news isn't better, but not being able to protect the code is no
> reason for not developing a good product and putting it on the market. i am
> much more concerned about someone copying my idea than stealing my code.
>
> michael
>
>
> Van: Rob <robzsKILLspamHICOM.NET>
> Aan: .....PICLISTKILLspam.....MITVMA.MIT.EDU
> Onderwerp: Reading a programmed PIC
> Datum: vrijdag 26 juni 1998 19:38
>
> Hello again fellow PIClisters,
>
> Can someone tell me if it's possible to read a PIC that has had it's
> protection fuse blown? I've heard there's a way to apply a voltage and
> put it into test mode. If I create a programmed chip and protect it, can
> someone else come along and copy it? Are there any ways to prevent this
> from happening?
>
> Thanks
>
> Rob
We (here on the list) do not know how to do it. But alas, with enough
intention (read : mony and time) all protections are defeated. The
Code-protect works (as far as I know) like a charm. But if you want extra
protection you can try to disable the programming-communications data-pin
(PB7). This is done by distroing the output-stage of that pin, resulting
in a input-only line. There was a thread about that some time ago (see the
archives.).
==================================================================
Andy Kunz - Statistical Research, Inc. - Westfield, New Jersey USA
==================================================================
> >One can connect input pins to VCC or GND, with as thick and as carefully
> >routed tracks as the real VCC and GND pins. Won't help too much though.
>
> If you aren't driving too much load, it IS possible to run the PIC using
> data pins to provide power sink/source.
>
> You _could_ make a PIC look like a 74-series device by making RB.7 and RC.3
> power and ground respectively.
THis is a really neat thing, but I wouldn't even know when this was an
appropriate way to power a PIC! I'm assuming the rated pin current
capacity determined the whole current consumption of the PIC?
> > Van: Rob <EraseMErobzsspam_OUTTakeThisOuTHICOM.NET>
> > Aan: PICLISTspam_OUTMITVMA.MIT.EDU
> > Onderwerp: Reading a programmed PIC
> > Datum: vrijdag 26 juni 1998 19:38
> >
> > Hello again fellow PIClisters,
> >
> > Can someone tell me if it's possible to read a PIC that has had it's
> > protection fuse blown? I've heard there's a way to apply a voltage and
> > put it into test mode. If I create a programmed chip and protect it, can
> > someone else come along and copy it? Are there any ways to prevent this
> > from happening?
> >
> > Thanks
> >
> > Rob
>
> We (here on the list) do not know how to do it. But alas, with enough
> intention (read : mony and time) all protections are defeated. The
> Code-protect works (as far as I know) like a charm. But if you want extra
> protection you can try to disable the programming-communications data-pin
> (PB7). This is done by distroing the output-stage of that pin, resulting
> in a input-only line. There was a thread about that some time ago (see the
> archives.).
Thanks, I shall check. Although the archives are pretty big to sift
through. Too bad there wasn't a better search scheme.
Rob wrote:
>
> On Mon, 29 Jun 1998, Andy Kunz wrote:
>
> > >One can connect input pins to VCC or GND, with as thick and as carefully
> > >routed tracks as the real VCC and GND pins. Won't help too much though.
> >
> > If you aren't driving too much load, it IS possible to run the PIC using
> > data pins to provide power sink/source.
> >
> > You _could_ make a PIC look like a 74-series device by making RB.7 and RC.3
> > power and ground respectively.
>
> THis is a really neat thing, but I wouldn't even know when this was an
> appropriate way to power a PIC! I'm assuming the rated pin current
> capacity determined the whole current consumption of the PIC?
>
> Rob
I'd like to add to the above that power to run code to convert pins RB.7
and RC.3 is reliant on initial power being recieved through their
internal protection diodes. Also, does this interfere with the power on
reset timer circuitry ? 18 pin PICS don't look much like any G.P. logic
chips that I know !
Regards,
Graham Daniel.
>THis is a really neat thing, but I wouldn't even know when this was an
>appropriate way to power a PIC! I'm assuming the rated pin current
>capacity determined the whole current consumption of the PIC?
Yes, you must really be running in a low-current situation. OTOH, you
COULD use this to de-polarize your system. If you READ the ports, see
which is high and which is low, you could then use it to power the system
if somehow the pins were connected to the "wrong" power rails.
Heh, just because it works doesn't mean it's recommended!
Andy
==================================================================
Andy Kunz - Statistical Research, Inc. - Westfield, New Jersey USA
==================================================================
nwlink.com
