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

ID 683494
Date 3/19/2020
Public
Document Table of Contents

11.4. BIOS Enumeration Issues

Both FPGA programming (configuration) and the initialization of a PCIe link require time. Potentially, an Intel FPGA including a Hard IP block for PCI Express may not be ready when the OS/BIOS begins enumeration of the device tree. If the FPGA is not fully programmed when the OS/BIOS begins enumeration, the OS does not include the Hard IP for PCI Express in its device map.

To eliminate this issue, you can perform a soft reset of the system to retain the FPGA programming while forcing the OS/BIOS to repeat enumeration.