Arria® 10 Avalon® Streaming with SR-IOV IP for PCIe* User Guide

ID 683686
Date 9/12/2024
Public
Document Table of Contents

7.2. Function Level Reset (FLR)

The following sequence of events occurs after a FLR to a Physical Function:
  1. The host stops all traffic from and to the Function.
  2. The host writes the FLR bit in the Device Control Register to trigger the FLR reset.
  3. The SR-IOV Bridge resets R/W non-sticky control bits in the Configuration Space of the Function. It notifies the Application Layer via flr_active_* signals.
  4. The Application Layer cleans up all state related to the Function. It asserts FLR Completed via flr_completed_* signal. The Application Layer should either discard all pending requests from the Function, or send Completions. If the Application Layer sends Completions, the host drops them without checking for errors.
  5. The SR-IOV Bridge re-enables the Function by deasserting the flr_active_* signal associated with this function.
  6. The host re-enumerates the Function.

This handshake ensures that the Completion for a request issued before the FLR does not return after the FLR is complete.