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Altera_Forum's avatar
Altera_Forum
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12 years ago

Transaction Reordeingr Feature in Altera's PCI Express Application Interface/DMA

Hi,

I am using the Altera's free application interface /DMA that comes with PCI Express core. I want to know whether this DMA has completion reordering feature or not? I used my hardware setup with jungo windriver. I am transferring 8Gb data from PC to DDR3 memory(attached on my custom board) using DMA. On one PC I found that the received data has some ordering issue quite frequently. But the strange part is that I am not getting this problem on another PC even after several transfers.

Since 8Gb data is quite big I should have problem on the other PC as well. What else can be the issue?

Thanks

Ali Umair

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    12 years ago

    I'd guess that the fpga generates the TLP in address order, however the PC end might generate terminations in a different order from which the requests are generated.

    Even snooping the cpu data cache could make a difference.