Searching \ for 'Protected Bit in 16C74/JW' 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=16C
Search entire site for: 'Protected Bit in 16C74/JW'.

Truncated match.
PICList Thread
'Protected Bit in 16C74/JW'
1997\04\22@132812 by Vlad A. Sheyanov

flavicon
face
Hi All !

How I can delete protected bit in 16C74/JW with UV eraiser?

Thanks

Best Regards
                                       Vlad.

1997\04\22@170156 by Andy Kunz

flavicon
face
At 08:41 PM 4/22/97 +0400, you wrote:
>Hi All !
>
>How I can delete protected bit in 16C74/JW with UV eraiser?

I have exposed it to UV for 2 hours continuous with window against bulb for
maximum intensity.

No guarantees.

Andy

==================================================================
Andy Kunz - Montana Design - 409 S 6th St - Phillipsburg, NJ 08865
         Hardware & Software for Industry & R/C Hobbies
       "Go fast, turn right, and keep the wet side down!"
==================================================================

1997\04\23@003903 by tjaart

flavicon
face
Vlad A. Sheyanov wrote:
>
> Hi All !
>
> How I can delete protected bit in 16C74/JW with UV eraiser?
>
> Thanks
>
> Best Regards
>                                         Vlad.

In the new parts it can only be erased with a jackhammer.
(Thank you, Microchip)

--
Friendly Regards

Tjaart van der Walt
spam_OUTtjaartTakeThisOuTspamwasp.co.za
_____________________________________________________________
| Another sun-deprived R&D Engineer slaving away in a dungeon |
|             WASP International  http://wasp.co.za           |
|             GSM and GPS value-added applications            |
|  Voice : +27-(0)11-622-8686   |   Fax : +27-(0)11-622-8973  |
|_____________________________________________________________|

1997\04\23@144528 by Gerhard Fiedler

picon face
At 06:35 23/04/97 +0200, Tjaart van der Walt wrote:
>Vlad A. Sheyanov wrote:
>> How I can delete protected bit in 16C74/JW with UV eraiser?
>
>In the new parts it can only be erased with a jackhammer.
>(Thank you, Microchip)

Why do you think this is an advantage? Erasing the protected bit after (or
even together with) all the program data doesn't seem like stealing code...

Gerhard

1997\04\23@172923 by Mike

flavicon
face
At 03:39 PM 23/04/96 +0000, you wrote:
>At 06:35 23/04/97 +0200, Tjaart van der Walt wrote:
>>Vlad A. Sheyanov wrote:
>>> How I can delete protected bit in 16C74/JW with UV eraiser?
>>
>>In the new parts it can only be erased with a jackhammer.
>>(Thank you, Microchip)
>
>Why do you think this is an advantage? Erasing the protected bit after (or
>even together with) all the program data doesn't seem like stealing code...

I think he was being a bit sarcastic - since its a pain if you do it
accidentally.

Rgds

Mike

Some say there is no magic but, all things begin with thought then it becomes
academic, then some poor slob works out a practical way to implement all that
theory, this is called Engineering - for most people another form of magic.
                                                                      Massen

1997\04\23@225743 by Mike Smith

flavicon
face
> >>> How I can delete protected bit in 16C74/JW with UV eraiser?
> >>
> >>In the new parts it can only be erased with a jackhammer.
> >>(Thank you, Microchip)
> >
> >Why do you think this is an advantage? Erasing the protected bit after
(or
> >even together with) all the program data doesn't seem like stealing
code...
>
> I think he was being a bit sarcastic - since its a pain if you do it
> accidentally.

I'm sure he was - and it renders the security bit useless in the windowed
version.  A pity, because when doing program development and delivering
'betas' to the enduser, a windowed protected PIC is just what you want.
The alternative is to factor the cost of 10 (or more) OTP's into your dev
costs, I guess.  Can we blame those cable TV hackers, for MicroChip doing
this??

MikeS
<.....mikesmith_ozKILLspamspam@spam@relaymail.net>

1997\04\23@230028 by Andrew Warren

face
flavicon
face
Gerhard Fiedler <PICLISTspamKILLspamMITVMA.MIT.EDU> wrote:

> Erasing the [Code Protect] bit after (or even together with) all
> the program data doesn't seem like stealing code...

   Right, Gerhard... But how would you ensure that the bit gets
   erased AFTER the program data?

   -Andy

=== Andrew Warren - .....fastfwdKILLspamspam.....ix.netcom.com
=== Fast Forward Engineering, Vista, California
=== http://www.geocities.com/SiliconValley/2499

1997\04\24@095332 by Gerhard Fiedler

picon face
At 18:35 23/04/97 -0800, Andrew Warren wrote:
>> Erasing the [Code Protect] bit after (or even together with) all
>> the program data doesn't seem like stealing code...
>
>    Right, Gerhard... But how would you ensure that the bit gets
>    erased AFTER the program data?

It seems possible to influence the "erasability" of memory bits by design.
They could put the configuration bits in a memory different from program
memory, thus making sure that they get erased after the program.

Tjaart seems to agree with me, I just read in another message. I think it
could be really helpful to be able to deliver completely erasable (and
therefore reprogrammable) chips _with_ (erasable) memory protection.

1997\04\24@101910 by John Payson

picon face
|Tjaart seems to agree with me, I just read in another message. I think it
|could be really helpful to be able to deliver completely erasable (and
|therefore reprogrammable) chips _with_ (erasable) memory protection.

The approach I would favor would be to have two protection bits--one erasable
and one not; if either is set for protection the device is protected, other-
wise is isn't.  In addition, I'd like to see a word of factory-programmed
metalized OTP added to the "configuration area" [e.g. maybe at address XX04,
just after the ID fuses] which would identify the procesor, revision, and
window-status.  This would allow programmers to operate more intelligently
and shouldn't cost anything significant (since I understand that most PICs
have some OTP there which was used for factory testing anyhow).

Attachment converted: wonderland:WINMAIL.DAT (????/----) (0000E704)

1997\04\24@112426 by mike

flavicon
picon face
In message  <EraseME01BC5093.E517FB60spam_OUTspamTakeThisOuTsupercat.pr.mcs.net> PICLISTspamspam_OUTMITVMA.MIT.EDU
writes:
>
> window-status.  This would allow programmers to operate more intelligently
                                  ^^^^^^^^^^^

When I first read this I thought you meant the people who write the code
and tap key-boards all day.

That was until I saw the oxymoron with the word at the end of the line ;-)


Regards,


Mike

1997\04\24@131045 by myke predko

flavicon
face
With this discussion, I have a question on how people develop their
applications and program devices.

When developing code, I always make sure the "__CONFIG" statement is used
and then with my PICStart Plus, I let the software load the configuration
flags, rather than doing it manually.  So far, I've been working with
16c73As for six months and never had a problem with an inadvertently set
Code Protect Fuse.

I reading the comments going back and forth, I'm wondering if:

1.  Not everybody knows about the __CONFIG Statement in MPASM.

2.  A lot of the non-Microchip programmers don't pull the configuration
information out of the .obj file.

I'm surprised that this aspect (I won't call it a "feature") of the PIC
generates such strong emotions.

Comments?

myke

"My ancestors didn't spend millions of years clawing their way to the top of
the food chain, just so I could become a vegetarian"

1997\04\24@131459 by mike

flavicon
picon face
In message  <@spam@3.0.16.19970424104738.526f601aKILLspamspampop3.nw.com.br>> KILLspamPICLISTKILLspamspamMITVMA.MIT.EDU writes:
> At 18:35 23/04/97 -0800, Andrew Warren wrote:
> >> Erasing the [Code Protect] bit after (or even together with) all
> >> the program data doesn't seem like stealing code...
> >
> >    Right, Gerhard... But how would you ensure that the bit gets
> >    erased AFTER the program data?
>
> It seems possible to influence the "erasability" of memory bits by design.
> They could put the configuration bits in a memory different from program
> memory, thus making sure that they get erased after the program.
>
> Tjaart seems to agree with me, I just read in another message. I think it
> could be really helpful to be able to deliver completely erasable (and
> therefore reprogrammable) chips _with_ (erasable) memory protection.
>

This is how it used to be on many of the older PICs (16C5x, C71, C61...),
but it was changed for a reason - the reason being that it was too easy
to defeat the copy protection.

If Andy Kunz is right (and I don't doubt him) over-cooking a code
protected part in a UV light will erase the code protect bit.


Regards,


Mike Watson
--
Mayes uk

1997\04\24@142851 by Andrew Warren

face
flavicon
face
Gerhard Fiedler <RemoveMEPICLISTTakeThisOuTspamMITVMA.MIT.EDU> wrote:

> It seems possible to influence the "erasability" of memory bits by
> design. They could put the configuration bits in a memory different
> from program memory, thus making sure that they get erased after the
> program.

   This is precisely what Microchip has already done with the
   Code-Protect bits, which is why they're so hard to erase.

   -Andy

=== Andrew Warren - spamBeGonefastfwdspamBeGonespamix.netcom.com
=== Fast Forward Engineering, Vista, California
=== http://www.geocities.com/SiliconValley/2499

1997\04\25@082821 by Gerhard Fiedler

picon face
At 11:33 24/04/97 -0800, Andrew Warren wrote:
>> It seems possible to influence the "erasability" of memory bits by
>> design. They could put the configuration bits in a memory different
>> from program memory, thus making sure that they get erased after the
>> program.
>
>    This is precisely what Microchip has already done with the
>    Code-Protect bits, which is why they're so hard to erase.

I must admit I didn't read the specs, but it seems (from the comments here)
that they are not specified for a higher erasing energy, but as
non-erasable. Somebody states that they are erasable if you "cook" the
device in UV (and gives his experience only as such, no warranty...), which
doesn't sound very much like designed for a (slightly) higher erase energy.

1997\04\26@075933 by Andy Kunz

flavicon
face
>I must admit I didn't read the specs, but it seems (from the comments here)
>that they are not specified for a higher erasing energy, but as
>non-erasable. Somebody states that they are erasable if you "cook" the
>device in UV (and gives his experience only as such, no warranty...), which
>doesn't sound very much like designed for a (slightly) higher erase energy.

Microchip intended them the code protect fuse to be OTP.

Andy

==================================================================
Andy Kunz - Montana Design - 409 S 6th St - Phillipsburg, NJ 08865
         Hardware & Software for Industry & R/C Hobbies
       "Go fast, turn right, and keep the wet side down!"
==================================================================

1997\04\30@201245 by Alex I. Torres

flavicon
face
> From: "Vlad A. Sheyanov" <TakeThisOuTloiEraseMEspamspam_OUTIBSS.IUF.NET>
> Subject:      Protected Bit in 16C74/JW
> To: RemoveMEPICLISTspamTakeThisOuTMITVMA.MIT.EDU
>
> Hi All !
>
> How I can delete protected bit in 16C74/JW with UV eraiser?

Keep it 2-3-4 hours under eraser. (check chip's temperature!)


  Best Wishes, Alex Torres.
  Kharkov, Ukraine, exUSSR.
  E-Mail To : altorEraseMEspam.....cook.kharkov.ua   via InterNet
              or 2:461/28             via FidoNet

--- GoldED 2.50.A0531+


'Protected Bit in 16C74/JW'
1997\05\01@041124 by Mike
flavicon
face
At 06:23 PM 30/04/97 +0200, you wrote:
> > From: "Vlad A. Sheyanov" <EraseMEloispamIBSS.IUF.NET>
> > Subject:      Protected Bit in 16C74/JW
> > To: RemoveMEPICLISTEraseMEspamEraseMEMITVMA.MIT.EDU
> >
> > Hi All !
> >
> > How I can delete protected bit in 16C74/JW with UV eraiser?
>
> Keep it 2-3-4 hours under eraser. (check chip's temperature!)

AND - make sure it cools down to room temperature before putting it back
in the programmer !

Rgds

Mike

Some say there is no magic but, all things begin with thought then it becomes
academic, then some poor slob works out a practical way to implement all that
theory, this is called Engineering - for most people another form of magic.
                                                                      Massen

1997\05\02@124013 by peter

flavicon
face
Andrew Warren wrote:
>
> Gerhard Fiedler <RemoveMEPICLISTspam_OUTspamKILLspamMITVMA.MIT.EDU> wrote:
>
> > Erasing the [Code Protect] bit after (or even together with) all
> > the program data doesn't seem like stealing code...
>
>     Right, Gerhard... But how would you ensure that the bit gets
>     erased AFTER the program data?
>
>     -Andy

Store the code protection bit in more than one location on the die.
Say twenty or thirty locations, then to make 100% certain, an opaque
layer covering the whole die, with semiopaque sections above
the interspersed code protection locations.

The code protection should be configured so that all the locations
must be erased before allowing code access

Peter Cousens
email: RemoveMEpeterTakeThisOuTspamspamcousens.her.forthnet.gr
snailmail: Peter Cousens, karteros, Heraklion, Crete, 75100, Greece,
phone: + 3081 380534,    +3081 324450   voice/fax

After Bill Gates announced to the world that he was Microsoft,
his wife was asked to comment. She said that as his wife, she
had been the first to notice this problem

More... (looser matching)
- Last day of these posts
- In 1997 , 1998 only
- Today
- New search...