Atmel EB42 automatic reset

I just started developing programs on Atmel's AT91EB42 evaluation board
using CrossStudio, which uses GNU toolchain.
Two days ago I noticed that after my program was loaded into SRAM
and started running, the board would reset itself after about 5
minutes.
The program can be as simple as an infinite empty loop and the reset
would still happen at roughly the same time. Initially, I thought it
was because of the watchdog timer has expired. But I later verified
that it was disabled, at least when the program started running.
I have tried three different borads. The results were the same.
I have run out of imagination how this could happen.
Any idea? Thanks very much.

On 17 Jun 2005 18:51:35 -0700, "hikari" <cjchen@eden.rutgers.edu>
wrote in comp.arch.embedded:

> I just started developing programs on Atmel's AT91EB42 evaluation board
> using CrossStudio, which uses GNU toolchain.
> Two days ago I noticed that after my program was loaded into SRAM
> and started running, the board would reset itself after about 5
> minutes.
> The program can be as simple as an infinite empty loop and the reset
> would still happen at roughly the same time. Initially, I thought it
> was because of the watchdog timer has expired. But I later verified
> that it was disabled, at least when the program started running.
> I have tried three different borads. The results were the same.
> I have run out of imagination how this could happen.
> Any idea? Thanks very much.

Possibilities only, since you haven't provided any real data:

1.  Overflowing the stack into code space and overwriting code.

2.  Getting trapped into a recursive loop that blows the stack.

3.  Writing through an invalid pointer that trashes either the stack
or data segment.

-- 
Jack Klein
Home: http://JK-Technology.Com
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hikari wrote:
> I just started developing programs on Atmel's AT91EB42 evaluation board
> using CrossStudio, which uses GNU toolchain.
> Two days ago I noticed that after my program was loaded into SRAM
> and started running, the board would reset itself after about 5
> minutes.
> The program can be as simple as an infinite empty loop and the reset
> would still happen at roughly the same time. Initially, I thought it
> was because of the watchdog timer has expired. But I later verified
> that it was disabled, at least when the program started running.
> I have tried three different borads. The results were the same.
> I have run out of imagination how this could happen.

You could check the voltage. If is goes below 3.0V the supervisory
circuit will reset the microprocessor.

You can also check the output of the Watchdog timer, an
output pin is tied to the MR of the reset controller.

Check all inputs to the reset controller to determine
the origin of the reset.