PCIe DMA in Ring Buffer Operation mode unable to be stopped

PCIe DMA in Ring Buffer Operation mode unable to be stopped

Title:
 PCIe DMA in Ring Buffer Operation Mode Cannot Be Stopped Unexpectedly

Issue Description:

When the PCIe DMA is configured to operate in Ring Buffer DMA mode for continuous transfers, the DMA operation cannot be stopped unexpectedly. If a device driver or application crashes while the DMA is running in this mode, the DMA engine may enter an unrecoverable state, requiring a full FPGA reset to restore normal operation.

In addition, when this DMA mode is used for video transfer, the start of the subsequent video frame becomes non-deterministic, which can result in a frame alignment shift. 

Affected Devices:

  • CertusPro‑NX
  • Certus‑NX
  • Avant device family
  • MachX05 device

Affected IP:

  • PCIex1 IP Core v3.0.1 and earlier
  • PCIe x4 IP Core v4.0.1 and earlier
  • PCIex8 IP Core v3.0.1 and earlier

Workaround:

Always perform a full system power cycle before relaunching the application or restarting the DMA transfer.

 Status:

This issue will be resolved in a future release of the PCIe IP Cores.