[sdiy] Parallel processing clock design question

[Tim Ressel]

I used to work for Ametek CRD. They were building
parallel 68020 machines based on Caltech's wormhole
messaging strategy. It's amazing how two fast new
Pentiums can outrun 1024 of the 25MHz 68020s we were
using!

--tr

--- John L Marshall <john.l.marshall at gte.net> wrote:
> Jim,
> 
> Did you work for n-Cube?
> 
> Take care,
> John
>
------------------------------------------------------------------
> ROBERT RICH will speak at this meeting.
> 
> Pacific Northwest Synthesizer Meeting
> 
> DATE CHANGE: August 2, 2003
> 
> www.sound-photo.com
>
------------------------------------------------------------------
> 
> ----- Original Message ----- 
> From: "James Patchell" <patchell at cox.net>
> To: "jbv" <jbv.silences at club-internet.fr>;
> "SynthDIY"
> <synth-diy at dropmix.xs4all.nl>
> Sent: Saturday, July 12, 2003 1:43 PM
> Subject: Re: [sdiy] Parallel processing clock design
> question
> 
> 
> >          It is best to use a clock source, such as
> a oscillator, that can
> > drive into the characteristic impeadence of the
> traces on your PC
> > board.  You then route the clock as a single
> continuous line, preferably
> > not through any vias with a terminator on the end.
>  I have found this
> > methode a pretty good one for routing clocks.  I
> used this in a system I
> > did that had 12,000 uP chips in it running in
> parrallel.
> >
> >          -Jim
> >
> >
> > At 10:32 PM 7/12/2003 +0100, jbv wrote:
> > >Hi again,
> > >
> > >Let's say I want several (2 to 5) uCs to run in
> > >parallel (yes, this is related to the recent
> thread
> > >"sound synthesis with uC") at high speed (40 /
> > >50 MHz or more).
> > >
> > >What is the best solution for clock design :
> > >
> > >1) use only 1 Xtal, which means rather long
> > >connections between Xtal and each uC clk
> > >input
> > >
> > >2) use 1 Xtal per uC, which means more parts
> > >and more PCB room but smaller connections
> > >
> > >3) use only 1 Xtal, but at lower freq and hook
> > >each uC clk input with a freq multiplier
> > >
> > >4) use another smarter solution that hasn't
> > >crossed my mind yet but that will be submited
> > >by some smart list member any time soon...
> > >
> > >Thanks in advance,
> > >JB
> >
> >
> 


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