Article ID: 000085545 Content Type: Troubleshooting Last Reviewed: 08/21/2023

Why does the Gen3 x8 AVMM 256-bit DMA design hang when the host attempts to perform two accesses in a row to the descriptor controller interface?

Environment

    Quartus® II Subscription Edition
    Avalon-MM Cyclone® V Hard IP for PCI Express Intel® FPGA IP
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Description

In Quartus® II software version 13.1, you may see the Hard IP for PCI Express® using Avalon® Memory-Mapped interface with DMA design crash if the descriptor controller interface is accessed using a burst transaction.

 

This is due to the Avalon-MM Descriptor Controller only supporting single cycle access.

 

If an Avalon-MM Master component performs two sequential accesses, or a burst transaction to the descriptor controller, then the Qsys interconnect component may generate a burst cycle from two single cycles.

 

 

 

Resolution

In Quartus® II version 13.1 Hard IP for PCIe Avalon-MM with DMA designs ensure that only single cycle accesses are made to the DMA descriptor controller interface.

This issue will be fixed in a future version of the Quartus® II software.

Related Products

This article applies to 3 products

Arria® V GZ FPGA
Stratix® V GT FPGA
Stratix® V GX FPGA

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