Searching \ for 'PIC12C509 and P16PRO troubles from a beginner' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: techref.massmind.org/techref/microchip/begin.htm?key=pic
Search entire site for: 'PIC12C509 and P16PRO troubles from a beginner'.

Truncated match.
PICList Thread
'PIC12C509 and P16PRO troubles from a beginner'
1998\04\09@111122 by Sheldon Rozario

flavicon
picon face
All the questions are related to p16pro and the PIC12C509.

       Before any body reads on i'm just warning you that i'm just a
beginner. I've got a few questions that i need answered.
Can PIC's (12C509) be used in the normal manner if it is not code
protected? and does the code protection just stop sombody copying it or
does it mean that it can no longer be written to, so if it is not code
protected can the code be overwritten or are they write once like CD's?
As you can see i don't know how to 'finalise' a chip. Also can I keep
the resistor between GND & MCLR even when programming the chip and if i
am using an ISA card LPT will the 330pF c4 make it worse or is it safe
to just leave it in anyway.
       I noticed that when i repeatedly read a chip (hit F6 5 times
straight)
that different data appears occasionally and the oscillator shows up as
being different, but most of the time the actual data that i programed
appears. Because of this i'm a bit scared to program too many PIC's with
the fear that i may destry them all.
       When i hit F2 (fuses) and the MCLR pin enabled is not checked
does this mean that i can no longer add data, or can i keep
adding/overwriting untill code protect is chosen?
       Also if anybody out there has a P16PRO and an ISA LPT or a motherboard
LPT can you pleas let me know the values of you Resistors and caps an
the rest of the setup like do you need a 470 ohm between GND & MCLR when
reading?
       Finally can you recommend any web sites that i can learn about
PIC12C509 and PIC's in general.

Thanks heaps
Sheldon
------------

1998\04\14@065223 by Caisson

flavicon
face
> Van: Sheldon Rozario <spam_OUTsjroz1TakeThisOuTspamSTUDENT.MONASH.EDU.AU>
> Aan: .....PICLISTKILLspamspam@spam@MITVMA.MIT.EDU
> Onderwerp: PIC12C509 and P16PRO troubles from a beginner
> Datum: donderdag 9 april 1998 16:56
>
> All the questions are related to p16pro and the PIC12C509.
>
>         Before any body reads on i'm just warning you that i'm just a
> beginner. I've got a few questions that i need answered.
> Can PIC's (12C509) be used in the normal manner if it is not code
> protected?

Yes.  Code-protect just alters the read-out when verifying/reading the code
with a programmer (or the like).

> and does the code protection just stop sombody copying it or
> does it mean that it can no longer be written to, so if it is not code
> protected can the code be overwritten or are they write once like CD's?

Code-protect will allow the PIC to execute the code, but when you try to
read
it (wit a programmer or the like) it will apear garbled.  In earlier
PIC-designs
the Code-protect bit was in EPROM and thus erasable (at the same time
all other code was erased, thus maintaning the integrety of the
code-protect).
In newer versions the Code-protect is a _fuse_ and thus a one-time only
thing
(even in the windowed versions !).

> As you can see i don't know how to 'finalise' a chip.

You don't 'finalise' a PIC.  You use the Code-protect or you don't. it's up
to you.

> Also can I keep
> the resistor between GND & MCLR even when programming the chip

I would reccomend a resistor between _VCC_ and MCLR (but you wanted to say
that anyway :-)


I'm sorry, but the rest of your questions are about the P16Pro, wich I
can't
answer.

{Quote hidden}

motherboard
> LPT can you pleas let me know the values of you Resistors and caps an
> the rest of the setup like do you need a 470 ohm between GND & MCLR when
> reading?


>         Finally can you recommend any web sites that i can learn about
> PIC12C509 and PIC's in general.

You've found the right spot here !

> Thanks heaps
> Sheldon

Greetz,
 Rudy Wieser

1998\04\14@170809 by Alessandro Zummo

flavicon
face
Il 14-Apr-98, Caisson scrisse:

> In newer versions the Code-protect is a _fuse_ and thus a one-time only
> thing
> (even in the windowed versions !).

That's really bad... i hope microchip will change this
behaviour....

--

  - *Alex* -

 http://freepage.logicom.it/azummo/

1998\04\14@185623 by n4ocb

picon face
Caisson  <caissonspamKILLspamTELEBYTE.NL> writes:

 > In newer versions the Code-protect is a _fuse_ and thus a one-time
 > only thing (even in the windowed versions !).

I found out this unfortunate characteristic by mistake. I programmed
a 12C671 windowed version with code protect on, something I had
previously enabled for the OTP versions I was sending out in
prototype units for evaluation.

Then I remembered something I read on this list. After about ten
sessions with a Datarase II it reads "blank" and programs as before.

--
/--------------------------\..\==================/
b r a d l e y   b a k e r    .....n4ocbKILLspamspam.....earthlink.net

1998\04\14@192353 by John Lowes

picon face
Alessandro Zummo wrote:
>
> Il 14-Apr-98, Caisson scrisse:
>
> > In newer versions the Code-protect is a _fuse_ and thus a one-time only
> > thing
> > (even in the windowed versions !).
>
> That's really bad... i hope microchip will change this
>  behaviour....
>
> --
>
>    - *Alex* -
>
>   http://freepage.logicom.it/azummo/

I would bet Microchip did this to keep people from hacking the code.
>From a security standpoint, it's great that they did something.
The 16c84 is used in europe in television access smartcards like the
ones sticking out of your DSS receiver.  It is easily hackable and I'll
bet there are millions of copies out there.

If you are just making prototypes in your basement, then don't blow the
fuse; security isn't important.  But make sure it's blown for shipped
product if you need for your code to be secure.

1998\04\15@083132 by Caisson

flavicon
face
> Van: Bradley Baker <EraseMEn4ocbspam_OUTspamTakeThisOuTearthlink.net>
> Aan: PICLISTspamspam_OUTMITVMA.MIT.EDU
> Onderwerp: Re: PIC12C509 and P16PRO troubles from a beginner
> Datum: woensdag 15 april 1998 0:30
>
> Caisson  <@spam@caissonKILLspamspamTELEBYTE.NL> writes:
>
>   > In newer versions the Code-protect is a _fuse_ and thus a one-time
>   > only thing (even in the windowed versions !).
>
> I found out this unfortunate characteristic by mistake. I programmed
> a 12C671 windowed version with code protect on, something I had
> previously enabled for the OTP versions I was sending out in
> prototype units for evaluation.
>
> Then I remembered something I read on this list. After about ten
> sessions with a Datarase II it reads "blank" and programs as before.

That's right !  _and_ it is the proper behavour for your controller. It
works
that way for all PIC's with the Code-protect bit in EPROM.
it's just that the code-protect bit is much harder to erase than normal
Program-data bits (to ensure that the code-data is gone before the
code-protect bit is cleared)

> --
> /--------------------------\..\==================/
>  b r a d l e y   b a k e r    KILLspamn4ocbKILLspamspamearthlink.net

Greetz,
 Rudy Wieser

1998\04\15@083959 by Alessandro Zummo

flavicon
face
Il 15-Apr-98, John Lowes scrisse:


> I would bet Microchip did this to keep people from hacking the code.
>> From a security standpoint, it's great that they did something.
> The 16c84 is used in europe in television access smartcards like the
> ones sticking out of your DSS receiver.  It is easily hackable and I'll
> bet there are millions of copies out there.

i bet they've changed the chip with a more secure one...

> If you are just making prototypes in your basement, then don't blow the
> fuse; security isn't important.  But make sure it's blown for shipped
> product if you need for your code to be secure.

selling a windowed pic is a non-sense for me...
an OTP part is cheaper... anyway shouldn't be simple
to expose to UV rays only the cp fuse and not the program memory....


--

  - *Alex* -

 http://freepage.logicom.it/azummo/

1998\04\15@084556 by Alessandro Zummo

flavicon
face
Il 15-Apr-98, Caisson scrisse:

>> sessions with a Datarase II it reads "blank" and programs as before.

> That's right !  _and_ it is the proper behavour for your controller. It
> works
> that way for all PIC's with the Code-protect bit in EPROM.
> it's just that the code-protect bit is much harder to erase than normal
> Program-data bits (to ensure that the code-data is gone before the
> code-protect bit is cleared)

there's an official statement about this? i need to be sure...
--

  - *Alex* -

 http://freepage.logicom.it/azummo/

1998\04\15@120014 by Mike Keitz

picon face
On Wed, 15 Apr 1998 14:43:18 +0200 Alessandro Zummo
<RemoveMEazummoTakeThisOuTspamITA.FLASHNET.IT> writes:
>> that way for all PIC's with the Code-protect bit in EPROM.
>> it's just that the code-protect bit is much harder to erase than
>normal
>> Program-data bits (to ensure that the code-data is gone before the
>> code-protect bit is cleared)
>
>there's an official statement about this? i need to be sure...

Microchip's official statement (which appears in newer data sheets) is
that they do not recommend setting the CP bits in windowed chips.  They
do not guarantee that these bits can be erased, so the chip may become
impossible to reuse.

Some people have reported that with some newer PIC chips, many hours of
exposure to UV will still not erase the CP bits.

Microchip seems to make no claims about the effectiveness of the code
protect logic, other than that it will prevent a normal programmer from
being able to read out the code.


_____________________________________________________________________
You don't need to buy Internet access to use free Internet e-mail.
Get completely free e-mail from Juno at http://www.juno.com
Or call Juno at (800) 654-JUNO [654-5866]

1998\04\15@165906 by Alessandro Zummo

flavicon
face
Il 15-Apr-98, Mike Keitz scrisse:


>>> it's just that the code-protect bit is much harder to erase than
>> normal
>>> Program-data bits (to ensure that the code-data is gone before the
>>> code-protect bit is cleared)
>> there's an official statement about this? i need to be sure...

> Microchip's official statement (which appears in newer data sheets) is
> that they do not recommend setting the CP bits in windowed chips.  They
> do not guarantee that these bits can be erased, so the chip may become
> impossible to reuse.

yes, but they MUST know how the cp bit is implemented..
everything would be easier if they could explain that....

> Some people have reported that with some newer PIC chips, many hours of
> exposure to UV will still not erase the CP bits.

:-(


--

  - *Alex* -

 http://freepage.logicom.it/azummo/

1998\04\16@063611 by Caisson

flavicon
face
> Van: Alessandro Zummo <spamBeGoneazummospamBeGonespamITA.FLASHNET.IT>
> Aan: TakeThisOuTPICLISTEraseMEspamspam_OUTMITVMA.MIT.EDU
> Onderwerp: Re: PIC12C509 and P16PRO troubles from a beginner
> Datum: woensdag 15 april 1998 14:26

[Cut]

> selling a windowed pic is a non-sense for me...
> an OTP part is cheaper... anyway shouldn't be simple
> to expose to UV rays only the cp fuse and not the program memory....

Your right.  A OTP is cheaper.  But do a test once and you have your
mony back.  To a test twice and you have a free (windowed) pic.

And about pin-point erasing of EPROM, It isn't easy for you & for me,
but for someone with time, equipment and/or mony it it doable.  The
gains could be very high !

Greetz,
 Rudy Wieser

1998\04\16@063613 by Caisson

flavicon
face
> Van: Alessandro Zummo <RemoveMEazummospamTakeThisOuTITA.FLASHNET.IT>
> Aan: PICLISTEraseMEspam.....MITVMA.MIT.EDU
> Onderwerp: Re: PIC12C509 and P16PRO troubles from a beginner
> Datum: woensdag 15 april 1998 14:43
>
> Il 15-Apr-98, Caisson scrisse:
>
> >> sessions with a Datarase II it reads "blank" and programs as before.
>
> > That's right !  _and_ it is the proper behavour for your controller. It
> > works
> > that way for all PIC's with the Code-protect bit in EPROM.
> > it's just that the code-protect bit is much harder to erase than normal
> > Program-data bits (to ensure that the code-data is gone before the
> > code-protect bit is cleared)
>
> there's an official statement about this? i need to be sure...

I attended some time ago a seminar from Micro-chip.  about the same
question was asked there. The answer we got was the answer I've given
you.

Greetz,
 Rudy Wieser

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