Re: Announce: RHDL-0.4.2 (Ruby HDL) an agile HDL

[e-mail] (john jakson) wrote in message news:<[e-mail]>...
> [e-mail] (Phil Tomson) wrote in message 
> > 
> > Synthesis would be hard enough... I think conversion to VHDL would be a 
> > better place to start.  Even that is a bit hard; there is no RHDL parser, 
> > it's pure Ruby.  To get there I would have to get the internal parse tree 
> > for the RHDL code from Ruby - this is doable, but it'll probably be a 
> > while before I get a chance to play with it (spring break is now over ;-).
> 
> I gave up on CtoV like that and went for full Verilog parser &
> compiler, results much much better, but much more work. Many things
> become possible with the internal tree.

We came to the same conclusions.  The earliest predecessor to Confluence was
a hybrid language built out of Python much like RHDL.  Even though it did
generate synthesizable VHDL, the language limitations were too great.

Once we moved to Confluence, the internal data structures gave us
far more flexibility.  It did take a lot more of effort -- ironically
the front-end parser was one of the simpler steps in the compilation
process.


> > 
> > Maybe.  I'm not too familiar with System C.  I did download their free 
> > version about a year ago and played with it a bit.  It seems to me that 
> > System C is just C++ with some added libraries.  Given that it's easy to 
> > interface C++ with Ruby (using swig) maybe that wouldn't be too hard to 
> 
> I concluded a long time ago that HDL tools that are directly
> compatible with leading EDA SW based on Verilog (or even VHDL if you
> must) are infinitely more valuable than creating new HDLs with ones
> favourite language that can't work with anything.
> 
> The only exceptions might be languages like Confluence/Matlab/.. that
> are intended for systems guys that at least emit C, Verilog equiv
> models.

Actually, most Confluence source code is written at the same level
as Verilog/VHDL.  The advantage Confluence has over HDL is it's clean
syntax and powerful semantics, which results in smaller, more flexible code.
One example is a scalable FIR filter with variable precision written in
less than 20 lines.

Of course you can define Confluence abstractions all the way up to
the system level, where ever that may be.

-Tom 

--
Tom Hawkins                             [e-mail]
Launchbird Design Systems, Inc.         http://www.launchbird.com/