Searching \ for 'Reading a programmed PIC' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/microchip/devices.htm?key=pic
Search entire site for: 'Reading a programmed PIC'.

Truncated match.
PICList Thread
'Reading a programmed PIC'
1998\06\26@162432 by Rob

flavicon
face
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

1998\06\26@205128 by Michael S. Hagberg

flavicon
face
>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

1998\06\27@172556 by Mark Willis

flavicon
face
Michael S. Hagberg wrote:
{Quote hidden}

 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, spam_OUTmwillisTakeThisOuTspamnwlink.com

1998\06\27@215216 by Timothy D. Gray

flavicon
face
:-) 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.

On Sat, 27 Jun 1998, Mark Willis wrote:

{Quote hidden}

1998\06\27@230351 by Michael S. Hagberg

flavicon
face
>:-) 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.

michael

1998\06\28@163050 by Marc Heuler

flavicon
face
Hi Michael (Michael S. Hagberg), in <003e01bda241$6e2a93e0$793ce6cf@michael> on
Jun 27 you wrote:

> nope. once you trace power, ground, xtal, and i/o it's not hard to figure
> out which processor family you're dealing with.

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.

1998\06\29@023514 by Dr. Imre Bartfai

flavicon
face
Hello all,

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.

Imre


On Fri, 26 Jun 1998, Michael S. Hagberg wrote:

{Quote hidden}

1998\06\29@070447 by Caisson

flavicon
face
> Van: Rob <robzsspamKILLspamHICOM.NET>
> Aan: .....PICLISTKILLspamspam.....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.).

Greetz,
 Rudy Wieser

1998\06\29@102759 by Andy Kunz

flavicon
face
>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.

       movlw   1xxxxxxxxb      ; 1 ==> power pin
       movwf   RB
       bsf     RP0
       movlw   0xxxxxxxxb      ; x = whatever you need, 0 = force output
       movwf   TRISB
       bcf     RP0

       movlw   xxxx0xxxb       ; 0 ==> ground pin
       movwf   RC
       bsf     RP0
       movlw   xxxx0xxxb
       movwf   TRISC

       ...

Your chip is now using specified pins as power!

Andy

==================================================================
Andy Kunz - Statistical Research, Inc. - Westfield, New Jersey USA
==================================================================

1998\06\29@142936 by Rob

flavicon
face
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

1998\06\29@142941 by Rob

flavicon
face
On Mon, 29 Jun 1998, Caisson wrote:

{Quote hidden}

Thanks, I shall check.  Although the archives are pretty big to sift
through.  Too bad there wasn't a better search scheme.

Rob


>
> Greetz,
>   Rudy Wieser
>

1998\06\30@105220 by g.daniel.invent.design

flavicon
face
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.

1998\06\30@135648 by Andy Kunz

flavicon
face
>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
==================================================================

More... (looser matching)
- Last day of these posts
- In 1998 , 1999 only
- Today
- New search...