Writing my own processor wouldn't have been a lot of fun if I didn't do it in my own Hardware Description Language.
Although now I believe the project to be a complete failure, I mention it here because people can learn from failures sometimes even better than from success.
I tried describing my processor in Verilog, but at that time I was a bit clumsy working with it and was not satisfied with the result. I made a specification for what a proper hardware description had to look like and I began implementing things in it even before I had a parser. The language is pretty much oriented towards gate-level design which nowadays hardly anyone does anymore. The syntax is vaguely C-ish.
I wrote a Manchester adder and another more complex adder (I don't remember which type) to try out the feel of my HDL. They can be both found in the attachments.
As I was learning yacc I also wrote a parser for the language, just before completely abandoning it.