求基于VC707 FPGA板的DDR3内存数据以太网传输至PC教程

Hey there! I’ve worked with the VC707 board a few times, so I can walk you through how to get data from its DDR3 memory sent to a PC over Ethernet—since you don’t care about speed constraints, this simplifies things a lot, so we can keep the implementation straightforward.

The VC707 comes with a built-in gigabit Ethernet PHY and supports Xilinx’s MIG IP for DDR3 control. The core idea is to:

1. Read data from DDR3 using the MIG IP
2. Package that data into Ethernet frames (we can even use a custom frame format to skip complex protocols)
3. Send the frames out via the Ethernet MAC IP
4. Capture and verify the data on your PC

Let’s break this down into manageable parts in Vivado:

• Add the DDR3 MIG IP
  Open Vivado’s IP Integrator, search for MIG 7 Series, and run the configuration wizard. Select the VC707 board preset (it’ll auto-configure pins, timing, and settings for the board’s DDR3 chips). Once generated, you’ll get an AXI interface to read/write DDR3. I recommend first testing this IP alone: write a block of test data to DDR3, then read it back and check for correctness (you can use an ILA probe to verify signals).

• Add the Tri-Mode Ethernet MAC IP
  Again in IP Integrator, pick Tri-Mode Ethernet MAC. Configure it for gigabit speed, and match the interface to the VC707’s Marvell PHY (check the board manual—you’ll likely need RGMII mode). This IP provides an AXI-Stream interface for transmitting/receiving Ethernet frames, which is perfect for our use case.

• Build a Bridge Module
  You’ll need a small custom Verilog/VHDL module to connect the DDR3’s AXI interface to the Ethernet MAC’s AXI-Stream interface. Here’s what this module needs to do:

  1. Initiate read requests to the DDR3 MIP to pull your target data
  2. Package the raw DDR3 data into an Ethernet frame: add destination MAC (your PC’s Ethernet MAC), source MAC (VC707’s Ethernet MAC—you can hardcode this), and a custom frame type (e.g., 0x1234 to identify your frames)
  3. Stream the completed frame to the Ethernet MAC’s TX AXI-Stream port
     Pro tip: If you don’t want to write the frame-packing logic from scratch, you can add Xilinx’s UDP/IP Stack IP, but custom frames are way faster to implement for your speed-unconstrained use case.

• Generate and Download the Bitstream
  Run synthesis, implementation, and generate the bitstream. Use Vivado’s hardware manager to download it to your VC707 board.

Since speed isn’t an issue, we can use simple tools to capture the data:

• Wireshark
  Install Wireshark, select your PC’s Ethernet interface, and set a filter for your custom frame type (e.g., ether.type == 0x1234). You’ll see the frames sent from the VC707, and can inspect the data payload directly.

• Custom Python Script
  If you want to automate data capture, use the scapy library. Here’s a quick example:

  from scapy.all import sniff, Ether
  
  def process_packet(packet):
      if packet.haslayer(Ether) and packet[Ether].type == 0x1234:
          raw_data = packet.payload.load
          print(f"Received DDR3 data (hex): {raw_data.hex()}")
          # Optionally save data to a file
          with open("ddr3_data.bin", "ab") as f:
              f.write(raw_data)
  
  # Replace "Ethernet" with your PC's network interface name (check in Wireshark)
  sniff(iface="Ethernet", prn=process_packet, store=0)
  

• Verify DDR3 First
  Before connecting to Ethernet, make sure your MIG IP is working correctly. Use Vivado’s ILA to probe the AXI read data and confirm it matches what you wrote to DDR3.
• Ethernet Connection Check
  Use a straight-through Ethernet cable to connect the VC707 directly to your PC, or ensure both are on the same local network. For custom frames, you don’t need to set IP addresses—Ethernet layer communication works directly.
• Debug with ILA
  Probe the AXI-Stream TX signals from your bridge module to the Ethernet MAC. Check that frames are being sent correctly, with the right MAC addresses and payload data.

内容的提问来源于stack exchange，提问作者user9684614