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Re: [f-cpu] I'm still in the warmup phase ;-)

Hi Guys,

On Thu, Nov 13, 2003 at 12:13:00PM +0100, Beat Steiner wrote:
> The manual has such a nice increment unit. It would be almost a pity to 
> replace it by add units.
> But two add units may be better than one add and one increment unit. Is 
> the find-first-lsb relevant
> to any software? Hash/compression algos or such?

A second adder could be added :)  But since FC0 will be a single-issue
core, that doesn't make much sense at the moment.

> What about a GREP engine? Suggested operands: byte to match, mask of 
> bits to match, register to search.
> Could find the character "p" in the 8 char string "f000-cpu" in some 
> clock cycles. Hmm. Was just an idea. We first
> should get a simple design running before adding fancy engines.

We already have such an engine, sort of:

	# load parameters...
	loadcons $0x7770632d30303066, r1	# that's "f000-cpu"
	loadcons $0x7070707070707070, r2	# that's 8 times a 'p'
	# and here we go:
	xnor.and.b r1, r2, r3
	# matching bytes are 0xff, others 0x00

> Was there already an attempt to implement an f-cpu with CPLDs (complex 
> programmable logic devices)?
> If we could couple maybe some 100 CPLDs (FPGAs or whatever), the design 
> could be easily tuned,
> debugged and corrected, without carving anything into silicon.
> We won't be faster than a pentium pro (clock freq about 33 to >100 
> MHz?), but the design process
> is significantly simplified. Simulation software is nice, but I prefer 
> HW -- its somehow more fun :-).

If you have the hardware and would help testing, that would be great.

 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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