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VDT plugin

VDT plugin screenshot

There is a Elphel video video tutorial that shows installation of this plugin and related software.

Table of Contents

VDT plugin documentation

Documentation is available in a separate vdt_docs repository. Here are some screenshots

Installation of VDT plugin and related programs

VDT plugin for Eclipse is designed to integrate different tools for Verilog-based FPGA design. Currently it supports only GNU/Linux operating system and tool specification file support Icarus Verilog simulator and Xilinx ISE and Vivado Webpack design suites. It also works with Altera Quartus tools for synthesising FPGA code for Altera devices. Below is detailed step-by-step installation procedure for Kubuntu 14.04 LTS (other GNU/Linux systems should not require significantly different installation). Latest tested versions of the programs are also specified.

Installation of Xilinx tools

Xilinx Webpack software (free for download) needs to be installed on a GNU/Linux computer according to the manufacturer recommendations on the same computer as the rest of the software or (preferably) on a separate system. VDT uses ssh and rsync access to the server running tools, the server can be in the same LAN or accessed over the WAN. Both ISE and Vivado tools are supported.

Programs and libraries installed from (K)ubuntu repositories

GtkWave (3.3.58-1)

sudo apt-get install gtkwave

other programs needed for building Icarus Verilog

sudo apt-get install autoconf gperf flex bison g++ zlib1g-dev libbz2-dev git

For simulation with Cocotb

sudo apt-get install python2.7-dev

Java JDK

For most tasks JRE is sufficient, but if you would like to be able to modify and recompile Verilog language parsing you will need java compiler that comes with the full JDK.

sudo apt-get install default-jdk

Icarus Verilog

Icarus Verilog has to be compiled from the source code that is available in git repository:

git clone git://
cd iverilog

Update: Removed instructions to modify Icarus code - current version does not need them anymore, so just proceed with

sudo make install

Default VDT configuration assumes Icarus is installed to the /usr/local/bin


Java compiler compiler is optional, as VDT provide both Verilog grammar source files and generated Java files. It is needed only if you need to change and recompile these files (for example adding support to not yet covered Verilog features).

JavaCC can be downloaded as Unzip it in any convenient location - this location will be provided to Eclipse later.

Eclipse IDE

You will need Eclipse IDE for Java EE Developers (capable of plugin development), latest tested version is Mars (eclipse-jee-mars-2-linux-gtk-x86_64.tar.gz). VDT plugin is experimental and I would recommend to have a separate (from your other development) installation. VDT uses modified version of VEditor and any other versions of VEditor installed will conflict with VDT.

There are still issues with GTK3 (refresh of the windows content, animated icons), all seems to work if Gtk3 is disabled (Gtk2 used instead) by adding the following 2 lines in the eclipse.ini file (it is in the same directory as eclipse executable) .


are added just before line


Additionally a fix is required to make menu tooltips visible ( : «go to system settings > color > options and make sure "apply colors to non-Qt colors" is switched off, then log out and back in and see if the colors are normal. The tooltips are not supposed to have a light background.»

Update for Eclipse Neon: Tested, instructions above are still valid (including using GTK2 instead of GTK3), in the installer the needed Eclipse IDE for Java EE Developers is the second choice in the menu. You also need to remove the following line in eclipse.ini. By default Neon installs executable and ini file to ~/eclipse/jee-neon/:


As it is not recognized on GNU/Linux (at least on my installation) and causes a crash at startup.

Installation of VDT plugin itself

VDT plugin uses modified VEditor plugin for Eclipse and because of the license incompatibility (Eclipse Public License v1.0 for VEditor and GNU General Public License v3.0+ for VDT plugin) it is not possible to distribute a pre-compiled version (.jar file), so the plugin code has to be merged (using provided script) and compiled/built as Eclipse plugin project.

Clone VDT plugin source code

git clone

Run VEditor installation/patch script from within the top directory of vdt-plugin


This will clone the original VEditor source tree as tmp/unmodified_veditor_1_2_0_clone, re-organize files to match VDT plugin code tree, apply patch and copy the produced files to VDT project locations (most under src/com/elphel/vdt/veditor and _generated), these files/directories are listed in .gitignore . When VEditor-related part of the VDT code will be changed (and so the vdt-veditor.patch) you will need to run ./ again

Import the VDT plugin project into the Eclipse workspace.

At this stage I hit GTK bug that caused Eclipse to crash, working solution is described in : For oxygen, edit the normally already existing file /usr/share/themes/oxygen-gtk/gtk-2.0/gtkrc and change GtkComboBox::appears-as-list = 1 into GtkComboBox::appears-as-list = 0

File->Import->Git->Projects from Git->Existing local repository-> Select directory where you cloned VDT
Import Existing Projects (wizard selection)

Keep both parsers and vdt checked and press Finish

Configuring JavaCC (optional)

In the Project Explorer window, expand the vdt project folder, right-click the buildjavacc.xml file and select Properties. In the new dialog window select Run/Debug Settings, press New and agree to the only suggested option: Ant Build.

If the New is grayed-out, go to Window > Preferences > General > Content Types > Text > XML > Ant Buildfile and add buildjavacc.xml

Then Select Environment tab and enter two variables by pressing New and then


Value: Folder path that contains Eclipse executable


Value: Folder path where was unpacked (ending with /javacc-6.0).

Building and running VDT

In the "Project Explorer" window, expand the 'vdt' project folder and double-click (open) the plugin.xml file.

Select the Overview tab at the bottom of the appeared window.

Under the Testing label, click the Launch an Eclipe application link.

You may also use "Run Eclipse Application" (green triangle) or "Debug Eclipse Application" (green bug) buttons on Eclipse toolbar to launch A new instance of Eclipse will open, this new Eclipse will have VDT plugin activated. You may minimize the original Eclipse window at this point (it can be used to monitor and fix plugin errors). Next you may create a new FPGA development project or import an existing one. We will use DDR3 memory interface project as an example.

If Validation window opens complaining about and org.apache.xmlrpc when you launch VDT plugin, you may disable it in Run -> Run Configurations... -> Eclipse application -> Plugins (tab) uncheck Validate Plug-ins automatically prior to launching

Import and configuration of the sample project in VDT

Sample project is a DDR3 memory interface for Xilinx Zynq SOC that does not depend on undocumented featuers and encrypted modules and can be simulated with the Free Software tools.

Import x393 project

You may already have it if you installed other software for Elphel NC393 camera development, if that is the case you can skip the next step and use ~/git/elphel393/fpga-elphel/x393/

git clone
cd x393

Python program used on the target and during Cocotb simulation requires Python numpy module, on Ubuntu you may install it with

sudo apt-get install python-numpy

The last command copies Eclipse .project and .pydevproject files to the working directory.

From the Eclipse instance that runs VDT plugin (not the one with the VDT source code) use the same steps as for importing VDT plugin code (described above):

File->Import->Git->Projects from Git->Existing local repository-> Select directory where you cloned x393
Import Existing Projects (wizard selection)

Keep both x393 and py393 checked and press Finish

Configuration of VDT for x393 project

The cloned x393 project does not include Verilog modules of Xilinx primitives that are required even for simulation of the design. The required library (unisims) is included with the Xilinx Vivado software and the proprietary license does not allow to redistribute it. VDT provides means to copy this library from your Vivado installation to the project, So for the next step you need Xilinx software to be installed on the same or different computer running GNU/Linux.

Open the top module (x393.v) in the Editor (or any othe Verilog file of the project)

Open "Verilog/VHDL' perspective:

Window->Open Perspective->Other->Verilog/VHDL

It should look as shown on screenshots in VDT-UserManualAddendum.pdf, with bottom-left panel showind "Design Menu" and FPGA-related tools

Configure access to the server with Xilinx tools

In the "Design menu" panel select "Package" icon, it will open a dialog with "Xilinx server setup" tab active.

If you have Xilinx tools installed on the same computer as VDT, leave the default value for Remote Host IP (localhost) and Remote user name (your current login name).

If you are using phisically different computer - change the both fields as needed.

You may also change Vivado Release to the current one, installation directory (if different from the default) and configure same parameters for Xilinx ISE if you plan to use it (VDT supports both)

Next you need to setup password-less access to the tools server based on the key pairs:

Generate ssh key (if you do not have it already). Use command line tool or expand Vivado Tools in the design menu, right-click Start remote Vivado session and select Generate public key (or use a key icon on the Design menu toolbar)

Send this key to the server - you may either use a command-line program ssh-copy-id or right-click Start remote Vivado session and select Setup connection to user@server (tools icon on the toolbar). This operation requires you to enter the password for the server and this requires a separate program to be installed, you can do this with

sudo apt-get install ssh-askpass

Update: In Kubuntu 16.04 ssh-askpass is not required, there is a similar program available in base installation. Just pay attention that the first pop-up window will ask not for the password, but for "yes".

If ssh will not find ssh-askpass or a similar program, it will fail and Eclipse console output will output the resolution suggestions.

With ssh-askpass a separate dialog window will open, likely the first question will be not the password itself, but your permission to connect to an unknown host, so just enter yes there.

If everything was configured correctly you may try opening remote Vivado session (later it will happen automatically when needed):

Right-click Start remote Vivado session and select Launch Vivado (door with entering green arrow icon on the toolbar)

If everything is correct, in Eclipse console you will see

puts "@@FINISH@@"

and a few secods later server response ending with


@@FINISH@@ sequence is just a marker to know server successfully finished the requested command Start remote Vivado session shold now show pulsating green dot to the right of it and the console is open for both VDT communication and you can also manually enter TCL commands as covered in Xilinx Vivado manuals.

Copy unisims library to the local directory

Vivado Tools -> Vivado utilities -> Copy Vivado primitives library to the local project

Patch primitive(s) to work with Icarus Verilog

Some of the Xilinx primitives can not be simulated correctly with Icarus Verilog, we will add more patches when we'll hit particular problems, for x393 only one file needs to be patched - OSERDESE1.v

Run patch command from the unisms subdirectory of the x393 project :

patch -p1 < ../unisims_patches/OSERDESE1.diff

In x393_sata project this command will be

patch -p1 < ../x393/unisims_patches/OSERDESE1.diff

After new files are added the project needs to be refreshed - you may click on the project name in the navigator window and press F5 key or right-click -> Refresh

There are many files in the library so refreshing make take a while.

Simulating x393 project with Icarus Verilog

Design Menu -> Verilog Development tools -> Icarus Verilog simulator

If you get many errors "Unknown module type", you may need to refresh the project (press F5) after adding unisims library files.

If everything will work correctly, Icarus will compile and simulate the design (some warnings in the beginning are not fixed yet). After that GTKWave will open the simulation results.

In the case of problems you may get more verbose output in the console if you right-click on the Icarus Verilog Simulator, select Tool parameters, open Options tab and check Show output with no errors/warnings