Re: Implementing an elegant range type.

[Brian Rogoff <bpr@shell5.ba.best.com>]

On Wed, 21 Mar 2001, Dr Adrian Wrigley wrote:
> I also have written a VHDL -> Ada translator,  which has the potential
> to allow hardware designs to migrate easily to software.
> Handling of "downto" in array indices is not trivial, and I have left
> this (very important!) feature out.  Does anyone else out there
> use or have translators between the two languages?

Nope, but such translators going either or both ways would be very useful. 
Believe it or not, I'm actually more of a Verilog guy (in Silicon Valley 
VHDL is not widely used) but I've definitely thought Ada had a lot of
potential here. It might be too late as C/C++ based hardware modeling is 
getting lots of press.

> I can also see application for Ada -> VHDL translation, but this
> really has to be limited to a subset in practice (no dynamic creation
> of tasks, exceptions or generic subprogram parameters in VHDL).

Have you seen Peter Ashenden's SUAVE enhancements to VHDL? It pretty much
makes VHDL into Ada 95.

> Since VHDL is one of the worlds most succesful hardware languages,
> I think it has the potential to help introduce Ada to many
> engineers largely unaware of its existence.   The numerous colleges
> that teach VHDL could easily justify teaching Ada95 as the
> "software counterpart".  The benefits of "the Ada way" are very
> apparent when co-designing hardware and software using VHDL and C,
> where it is routine to find the VHDL clarity and type checking
> show how inefficient development in "C style" languages really is.
> There are some, however, who advocate using "C style" languages
> for hardware design, since people can leverage their familarity
> with C in the learning process.  I do not agree with that approach.

I think Ada will be playing catch up, but it is a good idea. 

> Hope this sheds some light on Ada's relationship to VHDL as seen
> by someone who has used both extensively in commerce (am I alone?).

I'm with you in spirit, but Verilog is overwhelmingly more popular in the 
US and Japan than VHDL.

-- Brian