🚀 go-pugleaf

On Jan 11, 8:10 pm, Jim Thompson <To-Email-Use-The-Envelope-I...@On-My-
Web-Site.com> wrote:
> On Wed, 11 Jan 2012 10:43:15 -0800, John Larkin
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> <jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> >On Tue, 10 Jan 2012 18:02:50 -0800 (PST),BillSloman
> ><bill.slo...@gmail.com> wrote:
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> >>On Jan 10, 4:55 pm, John Devereux <j...@devereux.me.uk> wrote:
> >>> Robert Macy <robert.a.m...@gmail.com> writes:
> >>> > On Jan 10, 2:28 am,BillSloman<bill.slo...@ieee.org> wrote:
> >>> >> On Jan 10, 7:47 am, "David L. Jones" <altz...@gmail.com> wrote:
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> >>> >> > Just thought some might be interested in hearing our recent guest on
> >>> >> > our Amp Hour radio show, Dr Howard Johnson of "Handbook of Black
> >>> >> > Magic" fame:http://www.theamphour.com/2012/01/10/the-amp-hour-77-winsome-waveform...
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> >>> >> > Lots of history of the book, signal integrity, Gigabit Ethernet
> >>> >> > development, 90 degree PCB bends, audiophoolery, and a whole bunch of
> >>> >> > other talk over almost 1 1/12 hours.
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> >>> >> "Black Magic" is more notorious than famous. I own both it and it's
> >>> >> follow-up, and both have got some useful content but they are badly
> >>> >> organised and what useful content they do contain is hard to find.
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> >>> >> The field is still waiting for a decent textbook on high speed circuit
> >>> >> design and layout.
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> >>> >> This is one of the few matters on which John Larkin and I seem to
> >>> >> agree.
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> >>> >> --
> >>> >>BillSloman, Nijmegen
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> >>> > Perhaps, it is time for the first ever 'conference' book written by a
> >>> > consortium of engineers/scientists.
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> >>> > Put my name in for proffreading.  :)
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> >>> Great idea. Perhaps John Larkin, Jim Thompson andBillSlomancould
> >>> collaborate on it.
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> >>> Sure that will work out well... :)
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> >>I'm not sure what Jim Thompson might contribute. I've seen papers that
> >>worry about the characteristic impedance of connections on the silicon
> >>(or whatever) inside integrated circuits,
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> Written by clueless PhD's trying the publish or perish route :-)

The authors affiliations seemed to be with the semiconductor firms,
but that doesn't stop them from being clueless Ph.D.s.

> >>but I don't have the feeling
> >>that Jim designs stuff that's big enough and fast enough for him to
> >>need to know much about it.
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> What a fundamental fathead you are, Slowman.  Even Larkin knows I've
> designed quite a bit of PECL.

We all know that - you tell us about it at every possible opportunity.
None of its big enough that you are going to have start treating
interconnection on the chip as transmission lines.

> I have chips out there, commercial successes, running at 5GHz.

So what. 5GHz is 200psec and light travels about 6cm in that period -
I'd be surprised if any of your chips were as big as 1cm across. You
really don't have to worry about reflections from discontinuities in
the connections across you chips..

> >I get the impression that most interconnects inside ICs are primarily
> >distributed R-C things, not real transmission lines at all.
> >Propagation speed of interconnects is a big deal in routing fast logic
> >chips, but the speed of light isn't the issue.

Me too.

--
Bill Sloman, Nijmegen