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RE: From serial PMD call, 15 May




> -----Original Message-----
> From: Lindsay, Tom [mailto:tlindsay@xxxxxxxxxxxxxxxxxxxx]
> Sent: 18 May 2001 16:19
> To: DAWE,PIERS (A-England,ex1)
> Cc: 802.3ae Serial
> Subject: RE: From serial PMD call, 15 May
> 
> 
> So does this suggest that mask testing should not use a filter?

No, it should use a filter.
 
> I don't think so. One could still use a filter to pass the mask (to
> suppress overshoot and other distortions). If it still clears the
> corners with the filter, then obviously it would clear the corners
> without the filter.
>
> Can I assume that a filter was not used in your analysis where you let
> the mask set the risetime spec?

A filter was assumed and unfiltered risetimes quoted.

Perhaps we are at cross purposes?

Piers
 
> Tom
> 
> 
> -----Original Message-----
> From: DAWE,PIERS (A-England,ex1) [mailto:piers_dawe@xxxxxxxxxxx]
> Sent: Friday, May 18, 2001 3:13 AM
> To: Lindsay, Tom
> Cc: 802.3ae Serial
> Subject: RE: From serial PMD call, 15 May
> 
> 
> Tom,
> 
> At present the draft standard, and the link model, start with the
> unfiltered
> rise time.  The link model converts this into 10-90% rise time in box
> P4,
> "Ts(10-90)", which is used (box F14 and column F) to create filtered
> 10-90%
> rise times in box G14, ("Tc" at 2 m) and column G.  These are used to
> calculate ISI and other penalties.
> 
> I hope that this addresses your question,
> 
> Piers
> 
> > -----Original Message-----
> > From: Lindsay, Tom [mailto:tlindsay@xxxxxxxxxxxxxxxxxxxx]
> > Sent: 17 May 2001 23:50
> > To: DAWE,PIERS (A-England,ex1); 802.3ae Serial
> > Subject: RE: From serial PMD call, 15 May
> > 
> > 
> > Piers - In FC, the present ristime spec is without a 
> filter, however a
> > filter may be used (not required) to pass the mask test.
> > 
> > The concern is about risetime being too slow (the low 
> jitter case); I
> > don't think anyone is worried about it being too fast. It 
> may not have
> > large effect, but testing against a mask with a filter will 
> > require the
> > source to have a faster risetime than if measured without a filter.
> > Which scenario are you considering? Which case (of both) have been
> > considered in the link model?
> > 
> > Thanks,
> > Tom Lindsay
> > Stratos Lightwave
> > 425/672-8005
> >