[ibis-macro] Minutes from the 9 Jul 2013 ibis-atm meeting
- From: Mike LaBonte <mike@xxxxxxxxxxx>
- To: IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
- Date: Wed, 10 Jul 2013 07:39:26 -0400
Minutes from the 9 Jul 2013 ibis-atm meeting are attached.
Mike
IBIS Macromodel Task Group
Meeting date: 09 July 2013
Members (asterisk for those attending):
Agilent: * Fangyi Rao
* Radek Biernacki
Altera: * David Banas
Julia Liu
Hazlina Ramly
Andrew Joy Consulting: Andy Joy
ANSYS: Samuel Mertens
* Dan Dvorscak
* Curtis Clark
Steve Pytel
Luis Armenta
Arrow Electronics: Ian Dodd
Cadence Design Systems: Terry Jernberg
* Ambrish Varma
Feras Al-Hawari
Brad Brim
Kumar Keshavan
Ken Willis
Cavium Networks: Johann Nittmann
Celsionix: Kellee Crisafulli
Cisco Systems: Ashwin Vasudevan
Syed Huq
Ericsson: Anders Ekholm
IBM: Greg Edlund
Intel: * Michael Mirmak
Maxim Integrated Products: Mahbubul Bari
Hassan Rafat
Ron Olisar
Mentor Graphics: * John Angulo
Zhen Mu
* Arpad Muranyi
Vladimir Dmitriev-Zdorov
Micron Technology: Randy Wolff
Justin Butterfield
NetLogic Microsystems: Ryan Couts
Nokia-Siemens Networks: Eckhard Lenski
QLogic Corp. James Zhou
SiSoft: * Walter Katz
* Todd Westerhoff
Doug Burns
* Mike LaBonte
Snowbush IP: Marcus Van Ierssel
ST Micro: Syed Sadeghi
Teraspeed Consulting Group: Scott McMorrow
* Bob Ross
TI: Casey Morrison
Alfred Chong
Vitesse Semiconductor: Eric Sweetman
Xilinx: Mustansir Fanaswalla
Ray Anderson
The meeting was led by Arpad Muranyi
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Opens:
- Arpad: I added a last minute agenda item
- Walter: I would like time to discuss Resolve_Dependency
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Call for patent disclosure:
- None
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Review of ARs:
- Fangyi to add Tx_DCD example to BIRD 155
- Radek: There was discussion of not using Usage Out
- Fangyi: It is done, but it is an Rx example
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New Discussion:
Interconnect update:
- Walter: Time used for editorial work
- Arpad: We can drop this standing agenda item
Usage Out for Jitter parameters:
- Walter: There was objection to those parameters being Out.
- The idea was that there was nothing the tool could do with them.
- I think it was the wrong decision.
- It is now deprecated.
- SiSoft believes Out should be allowed.
- Fangyi: Agree, as long as the note about it is sent out.
- Radek: Is it too late to change for 6.0?
- Michael M: This would be unapproving an approved change?
- Radek: Yes.
- Walter: This should be legitimate by our rules.
- It may delay 6.0 due to voting schedule.
- Bob: It would be better in 6.0.
- Walter: Approving it at the next open forum would speed up the process.
- Walter motioned for the group to approve such a BIRD in advance.
- Arpad: Where there other reasons to take that Out?
- Walter: No, we might find out more from the minutes.
- Mike L: I could not find anything in the minutes.
- Todd: It may have been something about changing the course of the simulation.
- Arpad: That would apply to Model_Specific, but these are Reserved.
- Todd: I think you are right.
- Ambrish: In the minutes Walter said only RX_Noise should be Out.
- Did that make it to the spec?
- Bob: Rx_Noise can be Out.
- Rx_Sensitivity is Info or Out, a carryover from 5.1.
- Ambrish: The minutes say Ken objected to jitter being Out.
- Walter: A Nov 2011 draft allowed Out, a Dec draft did not.
- Arpad: Would Out be allowed for GetWave and Init?
- Bob: We should allow it for both.
- Walter withdrew his motion.
AR: Ambrish ask Ken Willis about reasons for jitter not being Usage Out
AR: Walter draft BIRD to allow Usage Out for jitter
Resolve_Dependency BIRD 155:
- Walter: Some times we want parameters to depend on corner or model name.
- AMI_Init does not have corner or model name as an input.
- We could allow passing input parameters.
- Ambrish: They could be Model_Specific.
- Walter: Corner can be, but not model name.
- Fangyi: Isn't the AMI root the model name?
- Walter: No you can't count on that.
- Todd: The root is supposed to be the model name.
- David: That is not correct.
- Walter: There may be other possible solutions.
- David: It should be resolved in the final version of this BIRD.
- Arpad: Each [Model Selector] entry has a unique name.
- David: But they usually all call the same DLL.
Eye mask definitions:
- Arpad showed a presentation on eye mask definitions.
- Arpad: Eyes have both width and height requirements.
- We lack timing for setup and hold checks.
- Rx_Receiver_Sensitivity only lets us bound top and bottom.
- A full eye mask would let us check setup and hold.
- These standards usually stay away from things in the core itself.
- It is not clear where Rx_Receiver_Sensitivity applies.
- The core logic is not part of AMI, but Rx_Receiver_Sensitivity may apply to
it.
- Some people think it applies at the analog model.
- Michael M: Is an eye mask just for a pass/fail check?
- Arpad: Yes, but also margins.
- David: Some people inject jitter and watch for failure.
- This is an indirect measurement.
- If you do both this and check CDR at the slicer you are double counting.
- Walter: There is a fundamental difference between eye opening and
Rx_Receiver_Sensitivity.
- Eye opening is slightly related.
- It is usually a rule for compliance to a specific standard.
- For DDR4 JEDEC has nomenclature for eye width and height.
- In SerDes eye masks are measurement masks, built into scopes.
- Ambrish: Is there a compliance requirement?
- Michael M: It is advantageous to have a compliance check that avoid getting
into inner details.
- Arpad: This is similar to Vinh/Vinl.
- We know the real chip will have smaller hysteresis.
- We can put in spec numbers or actual device numbers.
- Walter: Model makers will want to put in spec numbers.
- Some people will want actual operation though.
- Ambrish: AMI models are not made for a specific spec.
- Michael M: We could take a kit style approach with different kit types.
- Arpad: Do we agree we want this?
- David: How else would anyone characterize jitter without double counting?
- Ambrish: The jitter parameters handle that.
- Walter: Sometimes we get negative RJs.
- There probably will be a BIRD for DDR4.
- There are no timing constraints and no Vref.
- It will be done in legacy IBIS.
- Michael M: I would like to see an eye mask option.
- This came up at a 2008 Asia summit.
- It should ideally be compatible with AMI.
- Arpad: There would be voltage, time, and BER in the definition.
- Fangyi: That would be for pass/fail, BER would not be needed.
- Arpad: A BER would give a minimum to pass.
- Ambrish: The tool figures out BER.
- Michael M: Vinh/Vinl give a concept of voltages to guarantee latching, not
actual performance.
- Todd: We agree with David, it is baked into jitter.
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Next meeting: 16 July 2013 12:00pm PT
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IBIS Interconnect SPICE Wish List:
1) Simulator directives
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