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Modifing SAM7x256_Eclipse Demo for a SAM7x128

Posted by Billy Rafferty on April 10, 2008
Hi there,

I'm trying to port the SAM7X256_Eclipse example to a SAM7X128 part. However I am running into difficulties. In the original code the hash table is set to 24K. If I leave it at this the application takes up to much ram to fit. I can lower it but if I push it below 20K the program stops working.

I've been unable to figure out what is using so much memory.

I was wondering if anyone can suggest how I might get the example to work in 32K of RAM in the SAM7x128.

Also I was wondering where you can find the demo for the GCC tools


It does not seem to be in the Demo folder.

Many thanks,


RE: Modifing SAM7x256_Eclipse Demo for a SAM7

Posted by Patrick DEFLANDRE on April 11, 2008
Hello Billy,

You should probably don't run all the task on the demo if you want to reduce the heap space to less than 22 K.

For not running a task, simply comment it in the main function, but don't forget to comment the corresponding check in the prvCheckOtherTasksAreStillRunning function.

You can also don't use the lwip stack by removing the vlwIPInit and vBasicWEBServer Task.

Take care if you remove the vUSBCDCTask task, as it use an idle hook. If you want to remove this task, you will have to change configUSE_IDLE_HOOK to 0 in FreeRTOSConfig.h


RE: Modifing SAM7x256_Eclipse Demo for a SAM7

Posted by Dave on April 11, 2008
Very good answer.

For more information.

http://www.freertos.org/FAQHelp.html FAQ number 2.

and you answered your own last question by providing the link http://www.freertos.org/portsam7xlwIP.html - look at the "Source Code Organization" section of this page and it tells you where the code is.

RE: Modifing SAM7x256_Eclipse Demo for a SAM7x128

Posted by Billy Rafferty on April 11, 2008
Great news,

As per your advice I removed some tasks and it all works in s smaller Heap :o)

Thanks, you both have saved me so much time and my hair.



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