Receiving bad data from FIFO with DMA transfer

In SOPC, check that your avalon switch fabric is properly connected to your DMA port.

Not sure if this is your problem, but its a common thing to forget when using DMA:

henning

> I have some problems with the FIFO and reading DMA transactions.

Have you check for interference with the cache ? (if you have one)

If you have cache on Data, there are precautions to take to ensure the consistency of the external memory.

Hope this helps,

Bert

Hello Henning, hello Bert.

First of all i like to thank you for your ideas.

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>If you have cache on Data, there are precautions to take to ensure the consistency of the external memory<[/b]

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i&#39;m using a Nios/f core. To check if it&#39;s a cache issue i downgraded the core and removed the cache. the error remains.

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In SOPC, check that your avalon switch fabric is properly connected to your DMA port.[/b]

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I will go after the connections (again and again :-)).

________

Meanwhile i verified that Memory is OK: I made a testpattern, which i copy from onchip ram to SDRAM and back, and from SDRAM to SDRAM.

Hopefully someone else has hint or better a solution.

Are there some known issues about configurations, which should be avoided.

I will check everything step by step...

Thanks

Helmar

Problem solved...

the problem isn&#39;t FIFO. It seems that it is an "electrical" problem. so far it seems to work now.

thanks everyone for trying to help me out.

Best Regards

Helmar