Minutes from the March 18, 2020 IBIS Interconnect Task group meeting are
attached.
Regards,
Justin
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IBIS INTERCONNECT TASK GROUP
http://www.ibis.org/interconnect_wip/ ;
Mailing list: ibis-interconnect@xxxxxxxxxxxxx
Archives at //www.freelists.org/archive/ibis-interconn/ ;
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Attendees from March 18, 2020 Meeting (* means attended at least using audio)
ANSYS Curtis Clark*
Cadence Design Systems Bradley Brim
Intel Corp. Michael Mirmak*, Ifiok Umoh
Keysight Technologies Radek Biernacki
Mentor, A Siemens Business Arpad Muranyi*
Micron Technology Justin Butterfield*, Randy Wolff*
SiSoft Walter Katz*, Mike LaBonte
Teraspeed Labs Bob Ross*
Michael Mirmak convened the meeting. No patents were declared.
Justin Butterfield took minutes.
Review of Minutes:
- Michael called for review of the minutes from the March 4, 2020 meeting.
Randy Wolff moved to approve the minutes. Bob Ross seconded. The minutes
were approved without objection.
Review of ARs:
- Michael to request Steve Parker to subscribe to the mailing list.
- Michael has requested Steve to join the mailing list and post all the
documents. This will take some time to get these posted.
- Walter Katz to generate the BIRD text associated with the suggested PDN
modeling improvements.
- Michael noted this is done and Walter had sent out a new draft with these
changes.
- Michael to send out the latest EMD draft and task list.
- Michael reported this is done.
Opens:
- None.
EMD Draft Review:
Walter noted most of Randy's changes were editorial. Walter accepted these
changes and retained the comments which we need to discuss. He took that draft
and made the changes. Bob suggested to put draft 3 in the BIRD number.
Walter added a new section for [EMD Parts] and [End EMD Parts] keywords. He
reviewed the text for EMD Parts which assigns the parts to the IBIS or EMD
models as a level of indirection. Walter changed the Designator Map to specify
the Parts. He added "*" as a special character for a wildcard designator.
Randy asked if it should not appear in the name. Walter replied it is a
wildcard for connecting multiple pins.
Walter added a section for the [Voltages] keyword. Bob suggested to name it
Voltage List. Walter stated the first value is the signal_name. The other
columns are typ, min, max voltage values. He commented there may be some text
from the IBIS standard that could be added to this section. Arpad Muranyi and
Michael noted typos in the Description sentence. Randy commented the board
database may only have a typical voltage value. Walter agreed the typical
value could be done automatically, but the min and max values can be added to
the EMD manually.
Randy asked if the [Voltages] keyword would be required. Bob suggested to not
make it required. Walter agreed and made this change, but he would recommend
using the keyword.
Walter noted a change to the rail terminal rules where a list of pins from all
designators can be shorted together with the "*" in from of the designator.
Walter noted in the rail connection section the *.<signal_name> functionality
is added and the same was added for bus_label.
Walter added a new example with one terminal for all the EMD pins and one
terminal for all the designator pins. This would be the way most PDN models
would be connected.
Randy asked if we can agree on the name of the Voltages keyword. Michael
replied Voltage List was the idea from Bob. There were no objections. Bob
noted the keyword needs to be added to the hierarchy diagram. He also
suggested to make the column heading comments.
Walter suggested to accept all the current changes and Bob to make the changes
he would like to see [AR]. This will be a draft 4.
Bob commented he may change names of some of the keywords such as the EMD
Parts. Bob will add rules for the Voltage Lists for the different cases of how
the voltage list could be used. Michael suggested we can discuss these changes
after they are added in.
Michael noted there were 3 issues Walter had raised and asked which onese were
resolved with these recent changes. After some discussion, the group agreed
these changes resolved the issues. Bob noted the simplified PDN connections
are added with the ability to connect designator pins with a wildcard ("*"),
but we will need some additional rules and clarifications on this.
Michael asked about item #7 in the task list. Randy noted this is now
corrected. Michael marked this as done.
Michael asked about item #12. Bob asked how the rail voltages are created for
each interface. Walter noted some voltages could be generated internally and
may not be included. Bob asked if all such voltages would be required. Walter
noted the keyword is not required. Bob asked, if you have a list, are all of
the rail signal_names required. Randy suggested this is not required. Bob
noted we can write the rule this way, and we can cover all the cases and
overrides by external stimulus.
Michael asked about item #13 regarding new rules for Pin_Rail. Bob replied we
need to change Table 41 with "*.y". Michael combined item #13 with the Table
41 changes and reassigned this to Bob.
Walter commented tasks #10 and #11 are done in draft 3. Michael marked these
as done. Walter noted item #9 is done as well, and the PDN changes are a
result of creating an EMD for a DIMM.
Michael added items #15 and #16 for editorial changes. For item #14, Michael
asked if we want to copy the introductory text for typ, min, max from the IBIS
specification or refer to it. Bob noted we have expanded and contradictory
information, since we can mix voltages. Michael asked who should work on
this. Bob stated he can write this, but we would need to review this as a
group. He noted the voltages can be used as a directive, but the EDA tool and
user can override these.
Michael asked about item #8 and if this has been added to the BIRD draft.
Walter replied in the designator list we point to a part number which does not
map to the IBIS or EMD. This can be left up to the EDA tool, but this can be
specified with a part number.
Michael noted the first 4 items in the task list are pending. He would like to
start closing these items.
Randy noted for item #8 the simulator can pick any part number, but we should
review the rules, since it is required to have an EMD or IBIS file listed in
the EMD Part list. Walter clarified that the designator can point to a part
not in the list. Bob commented we should not have these type of holes in the
specification. Michael suggested to discuss this next time.
Next Meeting:
The next meeting will be March 25.
Randy moved to adjourn. Bob seconded. The meeting adjourned without
objection.
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Bin List:
EMD Comments to be Resolved:
(See BIRD202.1 tracking spreadsheet)
IBIS-ISS Parser:
- IBIS-ISS parser scope document
