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Altera_Forum's avatar
Altera_Forum
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15 years ago

DMA on a DE0

Hi all, Can someone verify for me that they have DMA to SDRAM working on a DE0 board ? I've been trying to get it to work for a couple of days, but no joy. Here's how it's set up in SOPC builde...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
15 years ago

If you get a message about "m_state" ........ and a bunch of text that is not really all that useful then I would start suspecting that reset could be an issue. If the download just says that the validation failed then it could be any number of things including a memory problem.

The SDR SDRAM controller doesn't make use of the first 0x20 words in the memory for calibration so you don't have to worry about that. I would recommend using a non-volatile memory for the reset vector since that's what the processor starts fetching instructions when coming out of reset.

Your code probably wouldn't be located anywhere but the first ~80kB of the memory however the heap is probably located in the memory you are testing so I wouldn't recommend doing that. You could hack the memtest software to allocate the memory instead of having it ask you over the terminal. This way it'll be safe for the test to clobber it since it was either allocated at compile time or at run time.