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TMS320F28379D: Are There Limits On DMA Transfer Sizes?

Part Number: TMS320F28379D
Other Parts Discussed in Thread: C2000WARE

Hello,

I'm trying to use DMA to read ADC results at a high speed into a temporary buffer, from which the results can be periodically processed.  I have proven out the process by reading one or two channels and everything seems to be working correctly.

However, everything seems to break when I try to use this technique for 5 or more channels.  It does not matter if I use 4 different DMA channels each pulling from 1 location, or a series of 4 locations read by a single DMA channel in one burst - however I've tried it, I can read from no more than 4 channels before the temporary buffer is filled with random data and the system crashes (presumably because the same 'junk' data fills up thread stack space as well).  It's as if the DMA starts doing unlimited transfers.

I believe this is just a DMA problem since I pointed to a predefined array as the data source instead of the ADC result registers, and the same behavior persisted.

I'm trying to store 1024 samples for each channel in the temporary buffer.  Is there some kind of hard limit in the micro that would give me trouble at 5 samples or more?

Thanks,

Jeff