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Honored Contributor I
727 Views

Running from external SSRAM issues

Hi, I am using custom board along with Arria II GX Fpga.I am trying to run nios program on external SSRAM (Cypress-compatible memory).The problem began recently.as i have experienced a short-circuit.The problem of short-circuit has been fixed.The program,though is getting stuck ( I am able to see it during debug ).Some printf commands are not executed (Though i see in debug that the program is going to the next command).Also,using malloc returns null,though I am trying to allocate small amount of memory - 76 bytes.Running the same program on Internal RAM poses no problems.I have also run the memory test program by Altera - and it has not detected any problems. 

Any help will be appresciated. 

Thank You, 

Michael
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Honored Contributor I
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Continuing the subject - further symptoms of the issue : 

in printf commands ,which are failing,i have seen in debug the return value of printf - and it's 0xffffffff (some negative number,which indicates that printf function has failure). 

In general,this is LWIP stack program.The failure of malloc occures in mem_malloc function ( if this lights up the subject )
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Honored Contributor I
8 Views

Quite possibly you are just running out of heap space for malloc() etc.

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Honored Contributor I
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That what is probably happening.But this does not happen while running on internal RAM.There is got to be some hardware issue with the SSRAM (and/or its SOPC component),i just can't figure out what it is and how to fix it :). 

I also want to point out that I haven't had any issue with the memory prior to short-circuit.
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