Re: [802.3_100GCU] WebPage Updates
Hi Charles
I get where you are going, but I am against removing the "improved fr-4" or
"enhanced fr-4" from any requirement.
My reasoning is that this implies all the channels we evaluate and the
standard we create are intended to run across fr-4 ... Which isn't true from
my point of view.
Take care
-joel
On 2/23/11 9:44 AM, "Charles Moore" <charles.moore@xxxxxxxxxxxxx> wrote:
> paul,
>
> I looked at the objectives for 802.3ba and kind of liked the wording
> there. Cribbing from it, how about:
>
> Provide Physical Layer specifications which support 4-lane 100 Gb/s
> operation over:
> * at least Xm over a copper cable assembly
> * at least Ym over a backplane
>
> This sidesteps the issue of defining "improver FR4", something which we
> carefully avoided defining in 802.3ap. If we do use the term "improved
> FR4", the actual definition will only come after we write a channel
> spec. Then "improved FR4" is defined as any fire retardant material
> which will allow you to build a compliant channel Ym long.
>
> charles
>
> |--------------------------------------------------------------------|
> | Charles Moore
> | Avago Technologies
> | APD
> | charles.moore@xxxxxxxxxxxxx
> | (970) 288-4561
> |--------------------------------------------------------------------|
>
>
>
> Kolesar, Paul wrote:
>>
>> John,
>>
>> Thanks for posting your planned co-authored contribution on
>> objectives. As you said, this contribution proposes the form of the
>> objectives and leaves the key parameters open. I have previously
>> commented to this forum about a particular form that, while apparently
>> approved in the past, is illogical, conflicting and ambiguous because
>> it mixes words that define minima with words that define maxima.
>> Specifically, slide 4 states the reach requirements using the phrase
>> ³up to at least X m². One can take this to define a maximum of X m
>> (i.e. ²up to²) or a minimum of X m (i.e. ³at least²). Given this
>> conflict the only logical interpretation that can simultaneously meet
>> both is a reach of _exactly_ X m. I do not find this acceptable and
>> have previously proposed to state these objectives clearly as minima
>> using the non-conflicting phrase ³of at least X m². This will avoid
>> some problems that have occurred in the past with interpretation when
>> the value of X was challenged.
>>
>> I also do not understand the utility of the phrase ³consistent with².
>> It appears to be a way to interject some flexibility. But I do not
>> have an appreciation for what that implies. Perhaps someone could
>> enlighten me. Without that insight I would further simplify the form
>> to the following.
>>
>> Define a 4-lane 100 Gb/s PHY for operation over copper traces on
>>
>> ³improved FR-4² for link lengths of at least ³X² m.
>>
>> Define a 4-lane 100 Gb/s PHY for operation over copper twin-axial
>>
>> cables for link lengths of at least ³Y² m.
>>
>> Regards,
>>
>> Paul Kolesar
>>
>> ------------------------------------------------------------------------
>>
>> *From:* John D'Ambrosia [mailto:jdambrosia@xxxxxxxxxxxxxxx]
>> *Sent:* Wednesday, February 23, 2011 2:07 AM
>> *To:* STDS-802-3-100GCU@xxxxxxxxxxxxxxxxx
>> *Subject:* [802.3_100GCU] WebPage Updates
>>
>> All,
>>
>> This email is to inform you of two updates to the Study Group Web Pages.
>>
>> First, Mark Bugg has provided a calibration file, which will allow
>> de-embedding of the board traces. This file may be found at
>> http://www.ieee802.org/3/100GCU/public/ChannelData/Molex_11_0210/2XCAL.zip.
>> My thanks to Mark for providing this file.
>>
>> Next, as discussed at our prior meeting, the SG needs to focus on
>> setting its objectives. To that end I have worked with Howard Frazier
>> and Adam Healey on a presentation (see
>> http://www.ieee802.org/3/100GCU/public/mar11/dambrosia_01_0311.pdf) to
>> discuss objectives for the project. We have proposed the forms of
>> several objectives (leaving the important details as TBDs). I would
>> ask that everyone review this presentation, and consider how the
>> presentation that they plan to submit will contribute to helping us
>> determine our objectives. This presentation is only intended as an
>> initial list of key objectives.
>>
>> Regards,
>>
>> John
>>