[SI-LIST] Re: SATA eye diagram - how much is too much
- From: Istvan Novak <Istvan.Novak@xxxxxxx>
- To: Charles.Grasso@xxxxxxxxxxxx
- Date: Tue, 05 Oct 2004 11:14:34 -0400
Charles,
I think this may be a grey area, where depending on the what is exactly
you measure and what are the quality/reliability expectations of your
system, you may need to take a further look.
One could argue that one violation (which may or may not turn into an
error in your system) per minute is not a big deal, and it is probably
true that if errors do not line up into longer bursts, it would be hard
to notice in a user-run system without careful measurements. However,
the performance numbers extrapolated from a relatively short period of
time assume that the statistics of noise/interference causing the
violations/errors do not change with time. In general, this is not
true. A simple example is violation/error introduced by data-dependent
crosstalk and ISI, induced for instance from a DIFFERENT, UNRELATED
subsystem. Unless you make sure that the neighboring subsystems, which
may induce noticeable noise onto your link under test are really
excercised over all of their possible combinations of activities, it is
very questionable to extrapolate from short samples.
Regards,
Istvan
Grasso, Charles wrote:
> Greetings!
>
> I have a question regarding the interpretation of the eye diagram data vis a
> vis
> SATA.
>
> How many violations of the eye does it take before a design is brought to a
> screeching halt? A follow up question:
>
> Can eye violations be graded in terms of severity based on the location
> of the violation (that is : at the outer bounds, or the internal eye
> trapezoid )?
>
> The basis of this question (naturally) is that I have SATA data that have
> exactly
> one 1 violation at the outer bound of the eye at 1 minute of data capture.
> Typical go/no go specification will determine that to be a fail. I am not so
> sure.
> Any insight would be greatly appreciated.
>
> Thanks
>
> Best Regards
> Charles Grasso
> Senior Compliance Engineer
> Echostar Communications Corp.
> Tel: 303-706-5467
> Fax: 303-799-6222
> Cell: 303-204-2974
> Email: charles.grasso@xxxxxxxxxxxx; <mailto:charles.grasso@xxxxxxxxxxxx; >
> Email Alternate: chasgrasso@xxxxxxxx <mailto:chasgrasso@xxxxxxxx>
>
>
>
>
> ------------------------------------------------------------------
> 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:
> //www.freelists.org/webpage/si-list
>
> For help:
> si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
>
> List FAQ wiki page is located at:
> http://si-list.org/wiki/wiki.pl?Si-List_FAQ
>
> List technical documents are available at:
> http://www.si-list.org
>
> List archives are viewable at:
> //www.freelists.org/archives/si-list
> or at our remote archives:
> http://groups.yahoo.com/group/si-list/messages
> Old (prior to June 6, 2001) list archives are viewable at:
> http://www.qsl.net/wb6tpu
>
>
--
Istvan Novak Sun Microsystems, Inc.
Istvan.Novak@xxxxxxx Workgroup Servers, BDT Group,
One Network Drive, Burlington, MA 01803
Phone: (781) 442 0340
------------------------------------------------------------------
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:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List FAQ wiki page is located at:
http://si-list.org/wiki/wiki.pl?Si-List_FAQ
List technical documents are available at:
http://www.si-list.org
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
