I have built a NIOS II system to verify MSGDMA. The structure is shown as below:
The steps it works:
When it begins to run, the system always hang on waiting for completion IRQ, but no IRQ generated. I checked the memory, some data were lost during transfer.
When I remove the delay module, and directly loopback the Avalon-S T port of Write Master and Read Master, everything goes well.
My question is , is it possible to add some processing module when MSGDMA in MM2MM mode ? if yes, How it handle it ?