IBIS Editorial Task Group Minutes
November 30, 2022
Attendees:
Intel Corp. Michael Mirmak *
MathWorks Walter Katz
Micron Technology Randy Wolff*
Siemens EDA Weston Beal, Arpad Muranyi*
Teraspeed Labs Bob Ross*
Minutes by Michael Mirmak
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No patents were declared.
Michael Mirmak called the meeting to order and took minutes. He thanked Weston
Beal for having taken the previous meeting's minutes.
Arpad Muranyi raised the issue of proposed minutes changes as noted on the IBIS
Editorial reflector:
"It will be voted on in the open forum this Friday."
I don't think we said/expected that. I think we said that we will schedule it
for a vote in the upcoming Open Forum Meeting for the following meeting...
I would also change these sentences a little:
"Arpad noted that the BIRD, beyond clarifying
the text of the specification, adds some comments that might change the
technical requirements in the specification. A DQS executable must be available
in simulation if a DQ model needs clock times input. The initial specification
of this functionality allowed the EDA tool to assume some clock_times input if
the DQS (clock source) model was not included in the simulation."
to (or something similar):
"Arpad noted that one of the changes in the BIRD, might be viewed as a
technical change, because it makes the DQS executable model required
even for the "Wave" case. Currently the DQS executable model is only
required for the "Times" case and the EDA tool is allowed to pass a
waveform into the clock_times input if the DQS (clock source) model
is not available for the simulation."
Randy noted that BIRD221 and BIRD222 are scheduled to be introduced in the IBIS
Open Forum teleconference on December 9.
Arpad moved to approve the minutes with the changes. Randy Wolff seconded the
motion.
No objections were raised. Minutes with changes were approved.
Michael reported that he completed his AR, the only one, which was to add
BIRD221 and BIRD222 to Draft 4 in anticipation of their approval.
He has not yet distributed this draft.
Arpad reviewed an issue with [Series Pin Mapping]. Customers asking about
cases where an element model (e.g., a resistor) is placed between two pins.
They end up being surprised when looking at simulation results for IBIS in
contrast to a topology placing a discrete resistor on the same schematic.
This is because there is an implied placement after the package because of the
use of the word "pin". Pad declarations were not added to IBIS until much
later.
In addition, Arpad found a sentence regarding Series Pin Mapping that is not
even technically correct. He has written the changes as a BIRD, but wanted to
know if
the changes could simply be an editorial update as part of 7.2 development, so
as not to delay the 7.2 vote.
Arpad's change involved adding a paragraph before the "Other Notes" section for
Series Pin Mapping.
The wrong sentence is, "The package parasitics and any other elements such as
additional capacitance or clamping circuitry are defined by the model_name that
is referenced in the [Pin] keyword."
This should be changed to something like:
"Any other effects such as additional capacitance or clamping circuitry are
defined by the [Model] whose name is referenced in the model_name column of the
[Pin] keyword for the corresponding pins."
Arpad noted that new Interconnect terminology could put series elements behind
the die terminal. Michael mentioned the possibility of defining an alternate
name mentioning Pads that was
equivalent to and acceptable instead of Pins; Bob opposed this as needlessly
complex. Arpad agreed, noting that the whole section would need to be rewritten
to accommodate an alternate name. It's
easier to add or alter a single sentence.
Arpad reiterated his question regarding whether a BIRD is needed for this, or
whether a simple editorial change was sufficient. Bob noted that doing
nothing is also an option.
Michael added that a fourth option exists: filing a BIRD intended for 7.3 or
later. Arpad noted that he would prefer to make the change sooner rather than
later, particularly as customers continue to ask.
Randy stated that editing in a single sentence can be done in Editorial. Bob
noted that "package parasitics" meant Rpin, Lpin, and Cpin originally. Arpad
added that the original text tried to capture
too many effects, observing that the phrase "and any other elements" is
ambiguous.
Bob stated that the document needs a second sentence to talk about package in
addition to the behaviors on the die. Arpad expressed that he wanted the
usage of "pin" to not be literal.
Regarding whether a BIRD is required, Bob observe that BIRDs are also editorial
changes; the extent of the change is the question here. Rewriting stuff means
a BIRD.
Arpad agreed to attempt to reduce the changes to two sentences, as an
editorial change, and send his new text to the reflector. [AR] If this is not
possible, then a BIRD will be filed.
Michael reviewed draft 4, noting that BIRD222 seemed to miss a sentence that
should have been highlighted or struck through. The absence of strikethrough
made it unclear whether the sentence
should be in the document or not.
The sentence reads:
"Although the clock times will generally be related to the unit interval for
the primary SerDes channel being simulated, there is no requirement that there
be any relationship between the
clock times in the clock_times vector and the actual waveform returned in the
primary channel."
Randy replied that he was pretty sure the sentence was intended for removal.
Arpad agreed, noting the possibility that a sentence that should have been
struck, wasn't.
Randy added that the sentence is clear, but the intent seems to be that it was
meant to be removed. The sentence was present in IBIS 7.1 and in IBIS 7.2
draft 3.
The team agreed the sentence should be removed, with no change required to
BIRD222.
Michael noted that a final highlighted "1/2 UI" mention appears in the Retimer
Time Domain Simulation Flow in Chapter 10, step 8. Randy replied that this
usage seems OK.
Randy asked whether Michael should send out Draft 4. Michael agreed to do
this. [AR]
Arpad moved to adjourn. Randy seconded. The meeting adjourned.
