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Re: [f-cpu] ASIC vs FPGA vs Emulation vs simulation



On Wed, Aug 27, 2003 at 12:29:33AM +0200, Yann Guidon wrote:
[...]
> Now, the "The VHDL is not compatible." argument is a critical
> point for F-CPU. If it gets implemented in one FPGA,
> one has to rewrite a good share of code. This would be a "fork"
> from the original source, but they have to be kept in synch anyway,
> or else advances in any branch will be useless for the others.
> And if another brand of FPGA gets used, this becomes another fork.

That's right.  I guess I also mentioned that quite a while ago, in one
of my rants ;)

> Now (or more precisely, since a few years) F-CPU development faces a
> big problem :
>  - either we concentrate on "portable-only code" that is useful
> only for high-level simulation (everybody can use it but it's slow)
> and synthesis (almost nobody can use it),

This should be the first step.

>  - or we decide to implement some code in FPGA, thus jeopardizing
> portability and dropping "Freedom" from the project names, just
> so early physical implementations can be used for hacking.

That will be the second.

> I'm among those who would like to try to put F-CPU code in
> FPGA, as i am getting fed up of doing "virtual things" only.

Me too.

> But then, it is possible only if we could get our hands on
> one FPGA board from all major manufacturers, or else our
> code would depend on the whims of only one of them.

There aren't so many manufacturers that produce FPGAs of the size we
need, are there?  E.g. you can forget Atmel for the moment -- their
AT40K is nice but much too small.  It would only be useful for unit
tests.

What we should do (IMHO) is:  Finish the generic code, and then ask
the major FPGA vendors if they would like us to "port" it to their
hardware, and if they're willing to donate some boards and software to
the project.  If they aren't, I wouldn't touch their hardware anyway --
I can't afford high-end FPGAs.

-- 
 Michael "Tired" Riepe <Michael.Riepe@stud.uni-hannover.de>
 "All I wanna do is have a little fun before I die"
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