Quartus® Prime Pro Edition User Guide: Debug Tools

ID 683819
Date 12/09/2025
Public
Document Table of Contents

8.1.2. Remote Debug

With remote debug, you can access debug infrastructure through an Avalon® Memory-Mapped (AV MM) interface instead of the JTAG pin connections.

You can use this access to create a debug host connection to an FPGA device without requiring a physical connection to the FPGA JTAG pins.

The general flow for remote debug is as follows:
  1. The debug agent logic collects debug data from design logic that is being debugged.
  2. The debug agent endpoint routes this data through the debug fabric to the debug host endpoint.
  3. The debug host logic uses an Avalon® memory-mapped interface to send the debug data to the host via the custom communication infrastructure.
  4. The custom communication infrastructure converts from Avalon® memory-mapped interface protocol to interact with the debug server running on the host.
  5. The debug server transfers the debug data to the debug application (for example, Signal Tap) for processing and presenting to the user.
Figure 132. General Remote Debug Interface Block Diagram


The HS ST Debug Interface IP supports multiple debug agent endpoints:
  • High-speed streaming debug agent endpoint interface:
    • Uses an Avalon® streaming interface to communication with the debug fabric.
    • Supports higher throughput for offloading data over the remote debug channel (for example, PCIe, Ethernet via HPS, or Ethernet via Nios® V).
  • Virtual JTAG or SLD agent:
    • Available when the optional JTAG-over-protool (JOP) functionality is enabled in the HS ST Debug Interface IP.
    • Uses an Avalon® streaming interface and JTAG interface to communicate with the debug endpoint IP.
  • Local debug via JTAG:
    • Enables you to switch between remote debug channel or JTAG at run time without having to recompile your design.

Because the HS ST Debug Interface IP has an Avalon® memory-mapped interface and the debug server communicates over a TCP/IP interface, some infrastructure (custom communication infrastructure) is needed to convert TCP/IP communication to Avalon® memory-mapped transactions between the two. The design of this infrastructure depends on your system-level design.

Remote Debug Tutorial Example Designs

Some remote tutorial example designs are available on the Altera® FPGA Developer Site (https://altera-fpga.github.io/) for various development kits. Older versions of these remote debug tutorial examples use the JTAG-Over-Protocol IP for remote debug while the newer versions use the High-Speed Streaming Interface IP: