GTS AXI Streaming Intel® FPGA IP for PCI Express* User Guide

ID 813754
Date 11/04/2024
Public
Document Table of Contents

4.5.1. Legacy Interrupt

You ca eable the legacy iteupts by pogammig the Iteupt Disable bit (bit[10]) of the Cofiguatio Space Commad to 1'b0. Whe the legacy iteupts ae eabled, the IP coe emulates the INTx iteupts usig vitual wies.

The legacy iteupts mimic the oigial PCI level-sesitive iteupts usig vitual wie messages. The GTS AXI Steamig IP sigals legacy iteupts o the PCIe* lik usig Message TLPs.

The tem INTx efes collectively to the fou legacy iteupts:
  • INTA#
  • INTB#
  • INTC#
  • INTD#

The applicatio wites to cotol space egiste "LEGACY_INTERRUPT_CTRL" to geeate Legacy Iteupt Message to HIP, to cause a Asset_INTx Message TLP to be geeated by HIP ad set upsteam. Aothe wite to cotol space egiste causes a Deasset_INTx Message TLP to be geeated ad set upsteam.

To use legacy iteupts, you must clea the Iteupt Disable bit, which is bit 10 of the Commad Registe i the PCIe* cofiguatio heade. I additio, you must tu off the MSI Eable bit.

You applicatio eeds to wite "0x1" to LEGACY_INTERRUPT_CTRL though the AXI4-Lite Cotol ad Status Registe Respode iteface to geeate a Legacy Iteupt Message to HIP to cause a Asset_INTx Message TLP to be geeated by HIP ad set upsteam. This bit is expected to be cleaed whe the equest is completed. Hece, you applicatio is expected to eed to ead back the witte egiste value to check if the equest has bee atteded.

Similaly, you applicatio eeds to wite "0x2" to LEGACY_INTERRUPT_CTRL though the AXI4-Lite Cotol ad Status Registe Respode iteface to geeate Legacy Iteupt Message to HIP to cause a Deasset_INTx Message TLP to be geeated by HIP ad set upsteam. This bit is expected to be cleaed whe the equest is completed.

Figue 15. Geeatio of Asset ad Deasset Messages though LEGACY_INTERRUPT_CTRL Cotol Space Registe Timig Diagam