[SI-LIST] Re: Fibre channel interconnect margins

  • From: steve weir <weirsi@xxxxxxxxxx>
  • To: David Instone <dave.instone@xxxxxxxxxx>
  • Date: Tue, 04 Jul 2006 02:11:39 -0700

David, I disagree.  It does not change causality.  It changes the 
incremental delay between two events.  Imagine for a moment that we 
have a simple relaxation oscillator as the basis of our VCO.  In the 
presence of an infinitely large noise pulse, which is the limit for 
random noise, it takes an infinite amount of time for the ramp to 
reach the threshold.  The next cycle will not begin untilt he current 
cycle completes.  It may sound like something from Douglas Adams, but 
it really is mathematically and physically sound.


At 01:50 AM 7/4/2006, David Instone wrote:
>Because it makes for a nice simple clean definition.  However, I 
>believe you have to take the real world into 
>consideration.  Allowing the RJ to be really unbounded means that 
>each edge in a bit stream could be advanced or delayed by an 
>infinite amount.  Taken to extremes this means that  the order 
>of  edges  could be reversed.  This is obviously absurd, the 
>measured time between edges can reduce until it is zero, it cannot 
>go negative.  The time between edges can of course go to +ve 
>infinity, but that isn't a bit error, the system has failed or been 
>switched off.
>steve weir wrote:
>>RJ really is unbounded by definition.
>>At 09:46 AM 7/3/2006, Steven Kan wrote:
>>>>Date: Fri, 30 Jun 2006 21:48:56 -0700
>>>>From: Alan.Hiltonnickel@xxxxxxx
>>>>Subject: [SI-LIST] Re: Fibre channel interconnect margins
>>>>In fact, I think that companies DO ship products that toss a random
>>>>error approximately every 10e-xx or so. Why? Because the statistical
>>>>theory behind those errors is that random/Gaussian noise is, by
>>>>definition, unbounded - errors are a fact of life, even if the error
>>>>rate is very low.
>>>I suppose we're way off in the weeds, here, but is the noise actually
>>>unbounded? Or does it just behave in a Gaussian-like manner within the realm
>>>of times/rates that matter for shipping product? I suppose if I sat in my
>>>chair for long enough, a truly unbounded system might cause a gold bar to
>>>pop into existence on my desk, but my empirical GBR (gold-bar rate) is
>>>currently 0.
>Dave Instone
>Oxford Semiconductor Ltd
>25 Milton Park
>Oxon ox14 4ea
>+44 (0)1235 824963

To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field

or to administer your membership from a web page, go to:

For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field

List FAQ wiki page is located at:

List technical documents are available at:

List archives are viewable at:     
or at our remote archives:
Old (prior to June 6, 2001) list archives are viewable at:

Other related posts: