Since I didn't get any more responses to this post (with this subject line), I
whether what I wrote actually expressed what I wanted to say (or ask)...
So, the question regarding "signal ground" or "local ground" raises the
question in my
mind, what we are trying to say (or emphasize) in IBIS. Is the message that
this A_gnd is
a local node, potentially independent for each [Component] and possibly
the famous SPICE (or IBIS-ISS) global ground, node 0? Or is the message that
a signal ground, as opposed to chassis or earth ground, without defining
should be treated as a global or local node (i.e. without defining whether they
be connected together when they appear in different [Component]s or kept
My understanding is that we are concerned about the former, and since "signal
doesn't seem to define whether it is global or local, I would prefer to stay
with the "local
ground" terminology. (Or take Brad's suggestion of using "local reference",
but if we go
that way, we need to change the entire spec for consistency).
I would like to get clarification on this, so I would know whether I need to
in this new BIRD draft (that is supposed replace BIRD158.7).
Speaking of which, the more I think about the 3rd drawing and the (modified)
it, the more I wonder what we are really trying to say with that figure and the
reason this is bugging my mind is because that drawing only shows Touchstone
for the entire channel. There is also a possibility that we might have
for the package models (as well as for the channel). If the package is
described with an
IBIS-ISS subcircuit that has more than one reference terminal (N+2 or more),
the text I
wrote with respect to an N+2 terminal channel model would also apply to such
So I am asking myself the question, how would I change that text (and possibly
drawing) to include the possibility of IBIS-ISS package models. The more I
think about this,
the more I start feeling that none of this discussion about channels and
belong to BIRD158 (or this new replacement BIRD), which is about BUFFER
With that, I am starting to lean towards removing the 3rd drawing and any text
about the channel and/or package in connection with that figure.
Please let me know if you have any questions/comments on this sooner than
this new BIRD draft could be finalized soon.
[mailto:ibis-interconn-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad
Sent: Wednesday, March 7, 2018 10:09 AM
To: ibis-macro@xxxxxxxxxxxxx; ibis-interconn@xxxxxxxxxxxxx
Subject: [ibis-interconn] Re: [ibis-macro] New BIRD draft for replacing
According to Wikipedia, "signal ground" means return path for signal and power:
Signal grounds serve as return paths for signals and power (at extra low
voltages<https://en.wikipedia.org/wiki/Extra_low_voltage>, less than about 50
V) within equipment, and on the signal interconnections between equipment. Many
electronic designs feature a single return that acts as a reference for all
signals. Power and signal grounds often get connected, usually through the
metal case of the equipment. Designers of printed circuit
boards<https://en.wikipedia.org/wiki/Printed_circuit_board> must take care in
the layout of electronic systems so that high-power or rapidly switching
currents in one part of a system do not inject noise into low-level sensitive
parts of a system due to some common impedance in the grounding traces of the
As far as I can tell, this has nothing to do with the question whether it is
or globally in a specific design... I believe it could go either way.
From: Walter Katz [mailto:wkatz@xxxxxxxxxx]
Sent: Wednesday, March 7, 2018 7:35 AM
To: Muranyi, Arpad <Arpad_Muranyi@xxxxxxxxxx<mailto:Arpad_Muranyi@xxxxxxxxxx>>;
Subject: RE: [ibis-macro] New BIRD draft for replacing BIRD158.7
Google "signal ground". is what we have been calling "local ground", and you
will get the following picture:
Google "local ground" and it returns nothing to do with electronics other than
"Local Ground is the ninth studio album by Irish folk
Altan<https://en.wikipedia.org/wiki/Altan_(band)>, released in March 2005 on
the Narada<https://en.wikipedia.org/wiki/Narada_Productions> label.", which can
be played on electronic audio equipment.
The word "local" appear in IBIS 6.1, and never in the context of a local ground
I therefore suggest that we consistently use "signal ground" instead of "local
ground" in both BIRD 158 and 189.
978.461-0449 x 133
[mailto:ibis-macro-bounce@xxxxxxxxxxxxx] On Behalf Of Muranyi, Arpad
Sent: Wednesday, March 7, 2018 3:42 AM
Subject: [ibis-macro] New BIRD draft for replacing BIRD158.7
In today's ATM teleconference I took an AR to start a new BIRD that would
replace BIRD158.7. The attached BIRD draft is my first attempt for that BIRD.
I took the approved BIRD158.7 and changed its file name along with some of
the header information. The only other thing I changed was the text related
to the reference nodes of the Touchstone models. I did all this with Track
Changes turned on, so that it would be easy to find my changes. I can add
anyone's name on the top who wants to be listed as a requestor...
Please review and reply with questions/comments.
Wil will most likely need to make changes to the
ANALYSIS PATH/DATA THAT LED TO SPECIFICATION
ANY OTHER BACKGROUND INFORMATION
sections to explain all this, but we can do that later.