Re: p16 in VHDL
Dear Misc readers:
Jaap wrote:
> Likely questions:
> - How easy is it to implement this processor core in one's
> own design?
I suspect it will depend on your experience and the tools
you have available. Dr. Ting has done a couple variations
of P8 and P16 in different forms. They seem pretty small
and simple even compared to John Rible's QS4 or QS5 mini-
RISC. But it did take Dr. Ting some effort to get each
design working.
If anyone is serious they should of course get the documenation
such as the complete listing of P8 in More on Forth Engines
volume 24. That also included an eForth for P8.
> - How reliable is it? (Are there ready to use test procedures?)
Dr. Ting did not build a test suite the way John Rible did
in his class for his chip. But Ting did publish an eForth
for P8 and this is what he has used as a test suite.
John had a whole suite of test programs that could run
under the simulator to make sure the design worked before
writing FPGA.
> - How about support, programming wise?
Ting has published 24 volumes of More on Forth Engines
which has included a variety of software by various people
for MuP21. There is very little difference between the
P8, P21, and P16 from a software point of view. P16 has
some F21 features such as memory addressing from R and
deeper stacks, but has the 2/ from P21 not F21 and does
not have the extended branching in F21.
In any event a dozen people have published software that
is a close match. The design is simple enough that
it should not be a serious problem.
> - What are the licensing costs if any? Copyrights?
Good question. I am not clear on that. Ting has
distributed schematics and high level source to help
spread the concepts and get other people involved
in the learning process. I suspect that if someone
did a commercial design that generated money that
there would be some kind of royaltee fee involved.
There are several patents involved, Chuck has several
and one is shared with Patriot. It is interesting
to note that the patent on Novix has almost expired.
> And why is seemingly important information for the MISC
> community presented first to the Forth idiots society (whoes
> members only have a marginal interest in the subject matter
> since Forth can be run on many platforms) and not presented
> here first, where the genuine MISC afficianados linger.
I presented both at the same time, but the first post to
the misc mail list didn't go through. I think I had changed
my reply to address (anything@ultratechnology.com will reach
me) and the list didn't forward the first message I posted.
I did note that there was only one comment made in c.l.f to
the p16 in vhdl thread, and it was a sort of dismissal.
Jeff Fox
