Cyclone® V Avalon® Memory-Mapped (Avalon-MM) Interface for PCI Express* Solutions User Guide

ID 683494
Date 10/24/2024
Public
Document Table of Contents

6. Reset and Clocks

Note: If FLR is active or has yet to complete, avoid performing a warm reset or asserting pin_perst. Otherwise, the PCIe link may become unstable and will not be able to recover without a cold reset.
Note: The minimum interval time required between two consecutive pin_perst's or hot resets is 60us to ensure link stability. More specifically, the deassertion of pin_perst or hot reset, and the assertion of the next pin_perst or hot reset should be separated by at least 60us.

The pin_perst signal from the input pin of the FPGA resets the Hard IP for PCI Express IP Core. This signal is also an input to the Hard IP reset controller driving the reset_status output that can be used as a reset signal for the Application Layer logic. This reset controller is implemented in hardened logic. The figure below provides a simplified view of the logic that implements the reset controller.

Figure 26. Reset Controller Block Diagram