This website is a recreation of the VHDL reference that was once hosted at www.truechap.demon.co.uk starting around 2001. The last archive of the website on archive.org was in 2005, so it is possible this is when the website was shut down, however due to the recent transfer of the demon subdomain to Vodafone, it is possible the website was still up until May 2020. That website is the earliest copy of the reference I could find, which leads me to believe Dave Trueman is the reference’s author. His website also hosted a short VHDL reference sheet as far back as 1998, which only adds credibility to this. However, it is possible Trueman’s version was a copy from another source, that of which is unknown.

A copy of the reference was archived on vdlande.com on or before 2009 (due to there only being one copy on archive.org, we can’t be sure when it was archived). It is missing a few pages, specifically:

  • Library Clause
  • Selected Signal Assignments
  • Type Declaration

There are archives of both of these websites on archive.org here:

Currently, there is also another copy of the reference hosted at www.ics.uci.edu here (specifically this is a copy of the copy found at vdlande.com). However, this archive is also missing the pages listed above, and the page for “Configuration Declaration”. It also includes a few VHDL reference PDFs that the original and vdlande.com did not. It has a Google archive header at the top due to how it was archived, but it is better that it was saved in any capacity than not at all.


This is not a direct 1:1 recreation. Corrections have been made for spelling and grammar mistakes, and information may be added or removed to reflect changes made in VHDL standards VHDL-08 and VHDL-19. Due to this, I have also archived the original references within this website and in the git repository:

Be careful: I did not break links to external websites or missing files - these are direct copies of what is available on archive.org.

Special thanks to:

  • Dave Trueman for (possibly) creating the original reference
  • The creator of VDLANDE.com for archiving the reference
  • Jayram Moorkanikara at UC Irvine for creating their own archive, which is still online today
  • The Internet Archive for their numerous contributions to history and culture preservation