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MehmetFide's avatar
MehmetFide
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2 years ago

How to stop Avalon DMA?

Hello, We have an NXP SoM module (with Linux) connected to an Intel Arria 10 FPGA through a PCIe bus. We use Arria 10 Avalon-MM DMA Interface to transfer data from FPGA to our Linux processor. The ...
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VenT_Altera's avatar
VenT_Altera
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2 years ago

Hi @MehmetFide,


Thanks for your reply.


We cannot intervene when the DMA operation is in the process.


To shorten the time to wait for a DMA operation, you may try to reduce the number of dword for one DMA operation, so that for each DMA operation it takes less time to complete the transfer. And, in between each DMA operation, add some code at the user application level to exit the loop before the next DMA operation starts.

Thanks.

Best Regards,

VenTing_Intel


MehmetFide's avatar
MehmetFide
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2 years ago

Hi @ventt ,

Even If I set the number of the dword size of the DMA to be transferred to 1, the DMA will wait forever until that dword became available in the FIFO because of WaitRequest control between FIFO and DMA. The FIFO may not have amount of data requested by the DMA when we initiate the DMA at the first place. Therefore we need to be able to cancel active DMA operation to make the DMA usable again.

Thanks.