Program Counter error?

[karmic]

I made an hdl file for the program counter using a register as the storage unit and kind of having the same logic by which a DFF makes a 1-bit, just more complex.  But I can't access a pc till Monday for some reasons, and the last time I tested the hdl file it seemed to give an error during testing (didn't have time to edit it then). The circuit I created looks fine to me and I can't point out the error. Can somebody please help me?
The hdl file is:
(Removed)

Edit: if I'm on the right track/practically created the PC, can someone tell me any other implementations of the PC? (for broadening my horizons)

[cadet1620]

Your PC is conceptually correct, but you have a few syntax errors in your HDL.

Inc16 does not have an input pin named 'a'.
You need to use 'true' and 'false' for 1 and 0 constants.

When you have your PC working, email it to me and I'll send back some alternative implementations.

Please edit your post to remove the [mostly] working HDL.

--Mark

[karmic]

Thanks Mark, it happens because I lack practice on a computer (don't have my own).
Also, didn't realize we can't put HDL in forums, thanks for pointing it out.

[cadet1620]

Temporarily posting HDL like you did so that we can help you is fine. Some of the error messages can be quite obscure and their cause hard to find.

--Mark