Searching \ for '[PIC]: ICD with pins RB6 and RB7 high' 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/devprogs.htm?key=icd
Search entire site for: 'ICD with pins RB6 and RB7 high'.

Exact match. Not showing close matches.
PICList Thread
'[PIC]: ICD with pins RB6 and RB7 high'
2002\04\18@103202 by Kevin Olalde

flavicon
face
I made a programming error and mistakenly loaded a program (using the ICD set to
debug mode) into a PIC16F871.  The programmer error is that I set PORTB to
output and raise pins RB6 and RB7.

Now, attempts to reload (or erase) the chip fail with a "No Target" message from
MPLAB.  A slightly modified version of the program (that leaves RB6 and RB7 as
output/low) works fine on another '871 chip.  Meaning this second chip gets
correctly recognized by the ICD and interacts as expected.

The 'failing' chip was working fine, and still seems to run the loaded program
correctly, it just seems as though the ICD doesn't recognize it.

Does this sound like a "working as designed" feature of the ICD, and I should
just reprogram the part in another programmer?

Thanks,
Kevin

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics


2002\04\18@182647 by Barry Gershenfeld

picon face
If it's wired properly the ICD can hold the processor in reset.  At
that point RB6/7 and all other pins should be set to input.  Though
I'm not sure how the ICD gets control other than through the debug
code that it installs.   But try hitting the Erase button to get
rid of your program, or make sure you have Erase All before Program
checked when you try to update with your new code.  (And make
sure you have your new code loaded :-)

That would be nasty if you could lock yourself out like that...I don't
think I'll try that right away (though I almost did yesterday--until
we realized we could enable Port B pullups instead of driving
them high).

Barry


At 10:29 AM 4/18/02 -0400, you wrote:
>I made a programming error and mistakenly loaded a program (using the ICD
set to
>debug mode) into a PIC16F871.  The programmer error is that I set PORTB to
>output and raise pins RB6 and RB7.
>
>Now, attempts to reload (or erase) the chip fail with a "No Target" message
from
{Quote hidden}

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics


2002\04\19@063437 by Kevin Olalde

flavicon
face
Thanks for the reply, the reminder about the ICD holding the chip in reset was
what was needed.

User error.  I had neglected to break the connection between MCLR and 5V (via a
1K resistor).  Once I had MCLR connected only to the ICD, things went much
better.

Thanks for the help.  Though chatty at times, this list (meaning its members and
administrators) is invaluable.

Kevin


Barry Gershenfeld wrote:
{Quote hidden}

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.


2002\04\19@202445 by Mahmood Elnasser

flavicon
face
Hi I had same problem with 16F876 using the icd to program it.
I managed to solve it by disabling the crystal oscillator while
programming, the funy thing its now working without disabling the
crystal oscillator.
I'm only using the icd to program it because I left my nice pro pic 2
programmer at home and I cant use the bootloader for this application.
Good luck.

{Original Message removed}

More... (looser matching)
- Last day of these posts
- In 2002 , 2003 only
- Today
- New search...