RE: [avr-gcc-list] Jtag ice

[Theodore A. Roth]

On Sun, 11 Jul 2004, James Dabbs wrote:

> > Anyone have problems with the jtagice and the avr butterfly board?
> With jtag ice
> > plugged in (either in debug or run) about 6 lines of the program
> execute (down to
> > an PORTB=, I think), then the device resets; if I unplug jtagice,
> everything
> > *appears* to work normally...
>
> For what it's worth..
>
> I used the JTAG ICE on an ATMega169 board (our own board) and never
> could get it working.  I could single-step through code AS LONG AS I
> NEVER PAUSED more than 5 seconds or so between lines; otherwise, the
> part would just start executing and the ICE would lock up.  I diddled
> with termination resistors, ICE speeds, bypass capacitors, versions of
> software, GDB, Avrstudio, IAR tools.. Nothing.  Getting the ICE working
> with this part was beyond my capability.  I finally got the s/w working
> by diddling and probing I/O lines, and finished the project 5 weeks
> late.  For the subsequent version, we replaced the AVR with a Phillips
> LPC2104 (ARM), and we bought a Nohau JTAG, and this worked OK.  With AVR
> projects these days, I don't even attempt using the ICE.  It's on a
> shelf in the lab.

Was your project using the watchdog reset? That kinda makes it tough to
do ICE debugging when the watchdog reset's the system.

I've seen my systems mysteriously reset quite often. Every time it's
been because of a bad pointer in my code.

---
Ted Roth
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