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5887 Discussions

MSGDMA MM to ST stuck on busy

New Contributor I


I am having an issue where my MSGDMA engine completes 1 transaction and then hangs.


In my application I have a DDR memory connected via a SDRAM hard memory controller to the input of the MSGDMA, the output gets sent out over Ethernet. The MSGDMA has been configured according to the following picture.


During set up, I reset the MSGDMA, once it's done resetting, I enable interrupts.

During transactions, I check that the interrupt is cleared, the descriptor buffer is empty, and the MSGDMA is not busy.

If all is clear, I send a descriptor that enables the transaction complete interrupt, and I set the length to 1000 bytes.

Once the interrupt asserts, I clear it and prepare the second descriptor.


Using Signal Tap, I see that first descriptor goes through, the interrupt asserts, and gets cleared. The second descriptor gets setup properly and is sent but no interrupt asserts and status register shows that the MSGDMA is busy.


Any advice would be helpful.

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1 Reply

Hi Sir,

Probably you can check the similar discussion as below:



Especially the first one which I believe in your case, you have enable burst mode and increase the BC.