View Full Version : In-Circuit Debugger Mode

Darrel Taylor
- 22nd January 2007, 00:11
Does anyone have any Links to info on the PIC's Hardware Debugger.

Looking for something that says how to set a BreakPoint, or something like that. (Or anything related)

I've googled it to death, but just come up with ICD2 ads.

Maybe it's a Microchip "Secret".


paul borgmeier
- 22nd January 2007, 06:48
Does this help?
EDIT: Section 2.7.2 looks (possibly) promising

Darrel Taylor
- 22nd January 2007, 09:12

Thank you very much Paul. That's exactly what I needed.

I guess my searching skillz need a little work.

Much appreciated!


- 23rd January 2007, 03:15
Watcha doin there Mr. wizard?

Darrel Taylor
- 23rd January 2007, 05:11
I truely wish I knew.

At this point, it's a Big Idea, searching for a purpose.

Got a lot of little pieces, and like Leggo's, I've got to put them together into something functional.
Just wish I knew what that was going to be. :)

It started out as a Visual Interface to a Servo driver. But it seems to have taken a left turn somewhere. :(

- 23rd January 2007, 18:57
I was just curious.

I tried looking up an appnote on this a while back myself, but it seems to be
some dark secret Microchip doesn't want to divulge.

Strange they would build-in this functionality, and never put anything
together showing how to use it.

David Barker
- 23rd January 2007, 20:55
At one time it looked like microchip might be fairly open with ICD and 16 parts. However, for 18 parts they just shut down. I agree with Bruce - it is something they don't want to publish in the public domain...

Darrel Taylor
- 24th January 2007, 00:08
They probably wanted to sell ICD2's without competition. But now that half of Taiwan and Hong Kong, know how to clone it. It's time they Pony'd up. (Not Likely)

And you're right, info on the 18F debugger is hard to come by, but I'm finding little bit's and pieces here and there that are looking promissing.

One interesting point, is that chips like the 18F4550 and 18F4321 etc. in the 44 TQFP package have a dedicated debugger port on the pins that are normally "No Connection". This opens up RB7:6 and MCLR/VPP for normal use, while still having debugger functions. 18F452 doesn't have it.

Probably the best info I've found so far is from http://www.picbook.com

They have a program, QwikBug developed by students at Georgia Tech. That's a debugger for 18F452 and 18F4520 with full source code. They list several Microchip engineers as references, so it looks like they got Microchip to give out a little more info.

Unfortunately, they use the USART for coms to the PC instead of the ICSP port, but it sure is a good start. (well Commented)

Still searching though.


- 24th January 2007, 01:51
Here's an ICD2 debug exec from an 18F452.

Darrel Taylor
- 24th January 2007, 01:57

I wanted that, but didn't know if it was right to ask for it.

But .HEX files are legal. :)

Thanks Bruce!


- 24th January 2007, 03:17
I'd love to be a fly on the wall, looking over Darrel's shoulder as he is working on this project ;).


Darrel Taylor
- 24th January 2007, 05:49

Darrel Taylor
- 24th January 2007, 08:14

No, I'm not good enough to draw that Fly. (yet)
It came from http://www.snowcrest.net/kitty/hpages/flys.html

One of these days I'll be able to do Original Art instead of just editing others. :)

But in the mean time, I got a good laugh out of it.
Hope you do too.


- 24th January 2007, 16:36
They probably wanted to sell ICD2's without competition.
But now that half of Taiwan and Hong Kong, know how to clone it.
It's time they Pony'd up.

Hi Darrel,

(This info was in the Elektor magazine 10/2006).

The bootloader file BL010101.hex is part of MPLAB.
(\Microchip\MPLAB IDE\ICD2).
Use this file to flash the PIC16F877 present on a ICD2
clone and you are ready to use it. Note that the file will
not work with a 16F877A. If you click in the link below
you will see a list of links. From the link icd2clone.narod.ru
you can download a bootloader for the 16F877A. If you
use it, there is no warranty that your ICD2 clone will work
with new versions of MPLAB. So just use the original file
with a PIC16F877.

The above info was in the Elektor magazine 10/2006.

I don't use PIC microcontrollers, I did not test the above.

Best regards,


Darrel Taylor
- 24th January 2007, 22:14
Thanks Luciano,

More good info.

I don't use PIC microcontrollers, I did not test the above.


You've been around here for years. Made 436 posts so far. Everyone loves your great links. And you don't even use PIC's?

I'm Dumbfounded.


- 25th January 2007, 10:50
Hi Darrel,

More links for you.

BehrendBug home page:

BehrendBug demo video (WMV format)

* * *

I was able to find these links with Google.
Searched string: "ICD2" INBUG
(Where "INBUG" is the bit7 of the ICKBUG register).

With the first link below I was able to find
the BehrendBug home page, which is the first link in this post.


Note that the second link (doc file) has a different path
on the server. (Maybe more or different info to dig out).
Note also that the DOC is not the same as the PDF.

The BehrendBug uses the serial port. If I find more information
about in-circuit debugging via ICSP interface pins / ICSP protocol,
I will post it here. (See the link below).

* * * *

PIC16F877 DOS:

Best regards,