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Example design for the Ethernet FMC using the hard GEMs of the Zynq
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Example design for using the Quad Gigabit Ethernet FMC with the Zynq/ZynqUS+ PS hard Gigabit Ethernet MACs (GEM) and the GMII-to-RGMII IP.

Ethernet FMC


This project is designed for Vivado 2018.2. If you are using an older version of Vivado, then you MUST use an older version of this repository. Refer to the list of commits to find links to the older versions of this repository.

Supported boards


This project demonstrates the use of the Opsero Quad Gigabit Ethernet FMC. The design demonstrates use of the GMII-to-RGMII IP core to connect the hard GEMs of the Zynq PS to the Ethernet FMC PHYs. All designs use the hard GEMs but some also use AXI Ethernet Subsystem IP.

Ethernet FMC Quad Gig AXI Ethernet

Build instructions

To use the sources in this repository, please follow these steps:

  1. Download the repo as a zip file and extract the files to a directory on your hard drive --OR-- Git users: clone the repo to your hard drive
  2. Open Windows Explorer, browse to the repo files on your hard drive.
  3. In the Vivado directory, you will find multiple batch files (*.bat). Double click on the batch file that is appropriate to your hardware, for example, double-click build-zedboard.bat if you are using the ZedBoard. This will generate a Vivado project for your hardware platform.
  4. Run Vivado and open the project that was just created.
  5. Click Generate bitstream.
  6. When the bitstream is successfully generated, select File->Export->Export Hardware. In the window that opens, tick "Include bitstream" and "Local to project".
  7. Return to Windows Explorer and browse to the SDK directory in the repo.
  8. Double click the build-sdk.bat batch file. The batch file will run the build-sdk.tcl script and build the SDK workspace containing the hardware design and the software application.
  9. Run Xilinx SDK (DO NOT use the Launch SDK option from Vivado) and select the workspace to be the SDK directory of the repo.
  10. Select Project->Build automatically.
  11. Connect and power up the hardware.
  12. Open a Putty terminal to view the UART output.
  13. In the SDK, select Xilinx Tools->Program FPGA.
  14. Right-click on the application and select Run As->Launch on Hardware (System Debugger)

The software application used to test these projects is the lwIP Echo Server example that is built into Xilinx SDK. The application relies on the lwIP library (also built into Xilinx SDK) but with a few modifications. The modified version of the lwIP library is contained in the EmbeddedSw directory, which is added as a local SDK repository to the SDK workspace. See the readme in the SDK directory for more information.

Board specific notes


  • This design supports the ZCU102 Rev 1.0 board. Use a commit before 2017/02/13 for the older Rev-D board design. Note that the FMC pinouts differ between Rev 1.0 and Rev D:
  • The HPC0 design uses 4x GEMs to connect to ports 0-3 of the Ethernet FMC.
  • The HPC1 design uses 3x GEMs to connect to ports 0-2 of the Ethernet FMC. The 4th port is left unconnected because certain pins required by the Ethernet FMC (namely LA30, LA31 and LA32) are left unconnected on the HPC1 connector of the ZCU102 board.


This board requires code in the FSBL to read the FMC's EEPROM and enable VADJ to the appropriate voltage. Without this code, the VADJ will not be enabled by default and the Ethernet FMC will not be powered. The code to do this was only released in the 2018.2 version of the tools, so if you are using an older version of the tools, you will have to reprogram the Infineon power management IC (IRPS5401) as described in this forum post:


  • The UltraZed design uses 4x GEMs to connect to ports 0-3 of the Ethernet FMC.

Trenz TE0808 Starter Kit

The base board TEBF0808 has a DIP switch that must be set correctly to enable VADJ of 1.8V. Set S5-4 to ON in order to set VADJ to 1.8V.

ZedBoard, MicroZed and PicoZed

When changing ETH_FMC_PORT from 0-2 to 3 (ie. when switching to GEM1), it has been noticed that you have to power cycle the board. When the SDK project is configured for AXI Ethernet, it must make some Zynq configurations that are not compatible with the GEM1 configuration.

Installation of MicroZed, PicoZed, UltraZed, TE0808 board definition files

To use the projects for the MicroZed, PicoZed and UltraZed, you must first install the board definition files for those boards into your Vivado and Xilinx SDK installation.

The following folders contain the board definition files and can be found in this project repository at this location:

  • microzed_7020
  • picozed_7030_fmc2
  • ultrazed_3eg_pciecc
  • TE0808_9EG_1E

Copy those folders and their contents into the C:\Xilinx\Vivado\2018.2\data\boards\board_files folder (this may be different on your machine, depending on your Vivado installation directory). You also need to make a copy into the Xilinx SDK installation at this location: C:\Xilinx\SDK\2018.2\data\boards\board_files.

Single port limit

The echo server example design currently can only target one Ethernet port at a time. Selection of the Ethernet port can be changed by modifying the defines contained in the platform_config.h file in the application sources. Set PLATFORM_EMAC_BASEADDR to one of the following values depending on the port you want to target, and the hardware platform:

ZedBoard and MicroZed designs

  • Ethernet FMC Port 3: XPAR_XEMACPS_1_BASEADDR

ZCU102 designs (HPC0 and HPC1)

  • Ethernet FMC Port 0: XPAR_XEMACPS_0_BASEADDR
  • Ethernet FMC Port 1: XPAR_XEMACPS_1_BASEADDR
  • Ethernet FMC Port 2: XPAR_XEMACPS_2_BASEADDR
  • Ethernet FMC Port 3: XPAR_XEMACPS_3_BASEADDR (only valid on HPC0 design)

UltraZed, TE0808 design

  • Ethernet FMC Port 0: XPAR_XEMACPS_0_BASEADDR
  • Ethernet FMC Port 1: XPAR_XEMACPS_1_BASEADDR
  • Ethernet FMC Port 2: XPAR_XEMACPS_2_BASEADDR
  • Ethernet FMC Port 3: XPAR_XEMACPS_3_BASEADDR

BSP Setting

  • When using ports that use AXI Ethernet IP, the BSP setting "use_axieth_on_zynq" must be set to 1.
  • When using ports that use Zynq GEM, the BSP setting "use_axieth_on_zynq" must be set to 0.

To change BSP settings: right click on the BSP and click Board Support Package Settings from the context menu.


Check the following if the project fails to build or generate a bitstream:

1. Are you using the correct version of Vivado for this version of the repository?

Check the version specified in the Requirements section of this readme file. Note that this project is regularly maintained to the latest version of Vivado and you may have to refer to an earlier commit of this repo if you are using an older version of Vivado.

2. Did you correctly follow the Build instructions in this readme file?

All the projects in the repo are built, synthesised and implemented to a bitstream before being committed, so if you follow the instructions, there should not be any build issues.

3. Did you copy/clone the repo into a short directory structure?

Vivado doesn't cope well with long directory structures, so copy/clone the repo into a short directory structure such as C:\projects\. When working in long directory structures, you can get errors relating to missing files, particularly files that are normally generated by Vivado (FIFOs, etc).

For more information

If you need more information on whether the Ethernet FMC is compatible with your carrier, please contact me here. Just provide me with the pinout of your carrier and I'll be happy to check compatibility and generate a Vivado constraints file for you.


Feel free to modify the code for your specific application.

About us

This project was developed by Opsero Inc., a tight-knit team of FPGA experts delivering FPGA products and design services to start-ups and tech companies. Follow our blog, FPGA Developer, for news, tutorials and updates on the awesome projects we work on.

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