Stratix V Avalon-ST Interface for PCIe Solutions: User Guide

ID 683093
Date 5/03/2019
Document Table of Contents

7.1. Interrupts for Endpoints

The Stratix V Hard IP for PCI Express provides support for PCI Express MSI, MSI-X, and legacy interrupts when configured in Endpoint mode. The MSI and legacy interrupts are mutually exclusive. After power up, the Hard IP block starts in legacy interrupt mode. Then, software decides whether to switch to MSI or MSI-X mode. To switch to MSI mode, software programs the msi_enable bit of the MSI Message Control Register to 1, (bit[16] of 0x050). You enable MSI-X mode, by turning on Implement MSI-X under the PCI Express/PCI Capabilities tab using the parameter editor. If you turn on the Implement MSI-X option, you should implement the MSI-X table structures at the memory space pointed to by the BARs.


Refer to section 6.1 of PCI Express Base Specification for a general description of PCI Express interrupt support for Endpoints.