by my reckoning, the only way to get to a code protected chip is to erase it
entirely... other wise whats the point of code protection if you can just
remove it with a config bit

hehehehe

On Tuesday 30 July 2002 11:27 am, you wrote:
> Thanks Wouter. Today evening i will implement and get back if i have any
> concerns.
>
> With Regards,
> Anbu
>
> -----Original Message-----
> From:   Wouter van Ooijen
> Sent:   Tuesday, July 30, 2002 1:38 PM
> To:     PICLIST@MITVMA.MIT.EDU
> Subject:        Re: is programming spec wrong?
>
> > Using ICSP, i have developed programmer for PIC 16F84. The
> > problem is if i try to unprotect the protected pic controller
> > i am facing some problem. I am following the sequence as below
> >          1. Load Configure ( command - 00) with data 3FF0
> >          2. Increment to 2007
> >          3. command 01
> >          4. command 07
> >          5. Begin program 08 with 10 ms delay
> >          6. command 01
> >          7. command 07
> >  But why i can n't defeat code protection. Any body can
> > please give me the correct sequence of commands to unprotect the chip.
>
> The only source for the secret unlock/erase sequence is of course the
> PIClist. At least that's where I have got my info from. But it looks
> suspiciously like what you do, except '3FFF' instead of '3FF0' (typo?),
> and an added 'erase data' sequence.
>
>        -- remove protection
>        target_send_6( 0x00 )
>        target_send_14( 0x3F, 0xFF )
>        for 7 loop
>           target_send_6( 0x06 )
>        end loop
>        target_send_6( 0x01 )
>        target_send_6( 0x07 )
>        target_send_6( 0x08 )
>        target_wait_ms( 10 )
>        target_send_6( 0x01 )
>        target_send_6( 0x07 )
>
>        -- erase data
>        target_reset
>        target_send_6( 0x03 )
>        target_send_14( 0x00, 0xFF )
>        target_send_6( 0x08 )
>        target_wait_ms( 10 )
>        target_send_6( 0x0B )
>        target_send_6( 0x08 )
>        target_wait_ms( 10 )
>
> Wouter

--
Thank-you for your time.

John Ward

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu