at91rm9200 Board gets reset spontaneously

Hi ,

Im trying to build a Development board for the AT91RM9200  and am using
SDRAM in 16 bit mode , and 2 Mb Flash. I have managed to Store U-boot
in the Dataflash and to get it to boot from it. The Atmel Utility picks
up U-boot from the Flash and runs it from SDRAM.

The problem im having is that spontaneously while running , the System
automatically Resets. This was not happening prior to running U-boot
from the RAM chip .

I connected the reset line to a CRO and there was no dip in the RESEt
line....What could the problem be? What other conditions (apart from
the reset line going low) could cause the CPU to reset?

Further , i also noticed greater noise on the reset line signal , once
the code was execuuted from SDRAM...is that acceptable ?(normal?)...

In the past , i have also faced this same CPU reset problem ...back
then changing the cable from the debug port to the serial communication
board solved the problem...If there is a hardware problem on this board
, what could it be and how can i isolate it ?


Thanks a lot in anticipation....

Mayank.

May Day ! Just caught a dip in the Reset Line on auto-resetting....Now
What could be causing that?

Mayank Kaushik wrote:

> Hi ,
> 
> Im trying to build a Development board for the AT91RM9200  and am
> using SDRAM in 16 bit mode , and 2 Mb Flash. I have managed to Store
> U-boot in the Dataflash and to get it to boot from it. The Atmel
> Utility picks up U-boot from the Flash and runs it from SDRAM.
> 
> The problem im having is that spontaneously while running , the System
> automatically Resets. This was not happening prior to running U-boot
> from the RAM chip .
> 
> I connected the reset line to a CRO and there was no dip in the RESEt
> line....What could the problem be? What other conditions (apart from
> the reset line going low) could cause the CPU to reset?
> 
> Further , i also noticed greater noise on the reset line signal , once
> the code was execuuted from SDRAM...is that acceptable ?(normal?)...
> 
> In the past , i have also faced this same CPU reset problem ...back
> then changing the cable from the debug port to the serial
> communication board solved the problem...If there is a hardware
> problem on this board , what could it be and how can i isolate it ?
> 
> 
> Thanks a lot in anticipation....
> 
> Mayank.

 any chance you can add a pull-up resister to the reset line???