The current release is 2021.4. The primary changes in 2021.4 are:

  • Full support for references, and pass-by-reference for function calls; 2019.11 had significant limitations
  • Better support for timing simulations; 2019.11 had limitations related to falling-edge clocks and particular clock waveforms
  • A new foreign function interface (this currently only supports Verilog tasks)
  • Support for Xilinx Vivado simulation
Support for Ubuntu 20 was added in 2021.4, and SLES 12 was dropped.


The Windows downloads are suitable for both 32-bit and 64-bit Windows. mtv and rtv are command-line tools, and the easiest way to use them is to first install Cygwin. During the Cygwin install, you should make sure to select the single tcl package. Tcl is required for the unit test environment.

The mtv download location is not important. However, if Cygwin is installed at C:\cygwin, then I suggest downloading mtv into a new directory at C:\cygwin\eda. This appears as /eda in the Cygwin environment. The mtv installation has to be un-tarred. To do this in a Cygwin bash shell, you should carry out these steps:

$ cd /eda
$ tar xvzf mtv-2021.4.1117-windows-10.tgz  # or mtv-2021.4.1117-windows-7.tgz

This creates the /eda/mtv directory. You will now need to modify /eda/mtv/ to tell rtv which simulator you have. Find this line in the file:

export RTV_SIMULATOR=icarus

and change icarus to whatever simulator you have. The text here is not arbitrary: it must be a heading name in the /eda/mtv/simulators.conf file. If you are using Riviera-PRO for mixed-language simulations (your own VHDL DUT, with an mtv-generated Verilog testbench), for example, you should replace this line with:

export RTV_SIMULATOR=aldec_mixed

This completes the installation. During normal usage, you can set up your environment for mtv as follows:

$ pushd /eda/mtv
$ source
$ popd

This sets up your Cygwin path to locate the mtv and rtv executables, the simulator configuration file, the internationalisation file, and so on.


The Linux downloads are suitable only for x86-64 distributions. There are no 32-bit or non-x86 builds. You will need to repeat the Windows instructions above for untarring the distribution, and selecting your simulator. In normal usage, you should source either or settings.csh to set up your environment.

The Linux downloads are available for the current releases of RHEL, SLES, and Ubuntu, together with the previous LTS version (except in the case of SLES; SLES 12 support was dropped in 2021.4). If you have a distribution that is not binary-compatible with one of these three, then you may still be able to run one of the static binaries. See the release notes for instructions on using the static binaries.

MD5 hashes

On Linux and Cygwin, md5sum will calculate MD5 hashes, and can be run as shown below. You should download md5sum.txt together with one or more of the distribution files.

   $ md5sum -c md5sum.txt

md5sum will attempt to find the files named in md5sum.txt, and will check their MD5 hashes. You can do this even if you have downloaded only one of the distribution files. In this case, md5sum will report that 7 of the files can't be found, but will check the hash on the remaining file.

Windows has a built-in utility (certUtil) for calculating MD5 hashes:

   C:\Users\evan\Downloads>certUtil -hashfile mtv-2021.4.1117-windows-7.tgz md5
   MD5 hash of mtv-2021.4.1117-windows-7.tgz:
   CertUtil: -hashfile command completed successfully.

mtv and rtv are distributed as compiled binaries, without source. The Licence Agreement is the LICENCE-2021.4.txt file in the distribution, which is reproduced here. You may not download or otherwise use or redistribute the software if you do not agree to the terms of the Licence Agreement.

Previous releases