GHDL is a GPL'ed VHDL simulator. GHDL implements the VHDL language according to the IEEE 1076-1987 or IEEE 1076-1993 standard. Nearly all VHDL87 standard and most features of VHDL93 are supported. GHDL has been used successfully to simulate the DLX and Leon processors.

GHDL is based on GCC compiler technology, and compiles VHDL code directly into executable binaries, which may be executed in the Terminal. These binaries accept parameters e.g. to control simulation time, or to create VCD waveform dumps.

To learn more about GHDL, read documentation, and find examples check this:

This page aims to provide a shrink-wrapped distribution as a ready-to-use installer for Mac OS X. 

GHDL is based on Ada. This makes GHDL difficult to compile on systems which do not come with a decent Ada compiler. While an Ada compiler is available for Mac OS X I have ran into quite a few issues trying to compile GHDL. These issues include Ada conflicting with Xcode, the Ada environmentnot fully compatible with Makefiles from the Linux world, weird linker problems and many more. For the time being I gave up on compiling GHDL. Instead I am currently providing an experimental package based on the Windows distribution and Wine. This solution should be fully transparent to the user with only one exception: The Windows distribution uses a JIT compiler instead of creating binaries. I will clean up the distribution a bit more and move it back to SourceForge as soon as I can.

To Download the native GHDL installer, go to the SourceForge project page:

GHDL requires Apple's free Developer Tools to be installed. The latest Developer Tools may be downloaded via the Apple Developer Connection:

GHDL is written in Ada95. I used GNAT (the GCC Ada compiler) to create the binary image. GNAT may be downloaded here:


The GNU Public License is the key to free software. To learn more about the goals and licenses of the Free Software Foundation see here:

This page is Copyright 2002-2005 Felix Bertram
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