[SI-LIST] Clarification of test points definition -- IEEE802.3ap Annex69B Ref. Model.

Hello,


It seems TP1,4 are intentionally vague.

tx block---TP1--conn--backplane--conn--TP4---rx block


 TP1 "cuts" somewhere between backplane mated-connector and tx asic, and
similarly for TP4 and the rx side.  The bkplane & connectors reside between
TP1 and 4.

Shouldn't TP1/4 exclude all tx/rx pcb elements?

Yet... TP1/4 would then include connector pads & a short lead-in on tx/rx
pcb side which, by definition, DOES have a partial tx/rx pcb stackup but I
assume that's ok.

Justification for excluding tx/rx pcb: the bkplane channel should be a
separate model so that plugins can be separately optimized and the backplane
w/ connectors standardized.

Lastly, why would the ieee propagate such "vaguery"?   On a semantic basis
alone there's reason for disappointment:

Sec. 69B.2: "The backplane interconnect is defined between test points TP1
and TP4 as shown in Figure 69B?1."  But TP1/4 don't define anything in the
figure (it's not made explicit what of the tx/rx pcb lies within 'backplane'
bordered by TP1/4).

I suppose I should assume that the vagueness is an implicit message:  "It's
up to you, buddy.".

Thanks for any clarification,

John

 -------------------

------------------------------------------------------------------
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:
http://www.freelists.org/webpage/si-list

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


List technical documents are available at:
                http://www.si-list.net

List archives are viewable at:     
                http://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: