IBIS Macromodel Task Group
Meeting date: 17 May 2011
Members (asterisk for those attending):
Agilent: * Fangyi Rao
Radek Biernacki
Ansoft: Chris Herrick
Danil Kirsanov
Ansys: Samuel Mertens
* Dan Dvorscak
Deepak Ramaswamy
Jianhua Gu
* Curtis Clark
Arrow Electronics: Ian Dodd
Cadence Design Systems: Terry Jernberg
* Ambrish Varma
Celsionix: Kellee Crisafulli
Cisco Systems: * Mike LaBonte
Stephen Scearce
Ashwin Vasudevan
Ericsson: Anders Ekholm
IBM: Greg Edlund
Intel: Michael Mirmak
LSI Logic: Wenyi Jin
Mentor Graphics: * John Angulo
Vladimir Dmitriev-Zdorov
Zhen Mu
* Arpad Muranyi
Micron Technology: Randy Wolff
NetLogic Microsystems: Ryan Couts
Nokia-Siemens Networks: * Eckhard Lenski
Sigrity: Brad Brim
Kumar Keshavan
* Ken Willis
SiSoft: * Walter Katz
Mike Steinberger
* Todd Westerhoff
Doug Burns
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
The meeting was lead by Arpad Muranyi
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Opens:
- Mike L: Mark Westerhoff has joined as a guest
- Also Mike can not attend next week
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Call for patent disclosure:
- None
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Review of ARs:
- Arpad update Table BIRD
- Done
- Walter send Time Domain GetWave Flow diagram for posting
- Done
- Walter send Backchannel proposal for posting
- Done
- Bob write a BIRD on correcting Table 1-3 in the spec. (Row 23).
- In progress, on hold
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New Discussion:
Arpad showed the Boolean BIRD draft:
- Bob: The only question is if it is case sensitive
- We have no Boolean type, this BIRD adds it
- Arpad: It still supports string, and that can be used
- Bob: Not tool supports this because we didn't define it
- It could be a string "True" or "False"
- Arpad: Boolean is already described in the IBIS spec
- Walter: This is an over sight in section 10
- BNF stands for "Backus-Naur Form"
- Bob: We have not defined the pipe character for OR
Arpad showed the Format Corner and Range BIRD:
- Arpad: Do we agree the GUI lets the user set typ/min/max corner?
- No disagreement
- Walter: I use typ/slow/fast to avoid the confusion over mapping
- Arpad: How do we know whether "slow" maps to "min" or "max"?
- Fangyi: The reverse problem already exists, mapping min/max to slow/fast
- Todd: The reverse is the bigger problem
- Walter: IBIS already has the typ/slow/fast concept
- Bob: They map to the same thing, practically speaking
- Todd: TTL gets slower when hotter
- Semi vendors specify typ/slow/fast
- I like that better
- Bob: It means weak/slow, strong/fast
- Arpad: Does Range have typ/min/max too?
- Walter: Range gives a choice between 2 values
- Todd: It is continuous
- Ambrish: There is no defined increment?
- Todd: Right
- Bob: Only one value is sent to the DLL
- My understanding is it has an increment
- Walter: Every format defines allowed values
- Todd: A small set of values would use List type
- A larger set would use increment
- Arpad: Page 147 has only slow and fast, no typ
- These are selected by position
- Bob: That is a mistake
Arpad showed the AMI Function Return BIRD draft:
- We must clarify what is returned when there is no data
- Failure=0, success=1
- Walter: There should be a message mechanism to give the reason for failure
- That may be beyond the scope of this meeting
- Arpad: Some tools use success=0
Arpad showed the AMI_parameters_out BIRD:
- We should have a 3.2.1.7 section for AMI_parameters_out
- Input should be optional
- Ambrish: It should be optional
- Bob: Is Init required?
- Yes, but no parameters are required
- Arpad: Are we allowing empty strings?
- Walter: Code assuming a string is coming would expect a pointer
- Arpad: Do we allow NULL pointers?
- Something has to be passed to Init
- Walter: NULL pointer should not be allowed
- Mike: Who frees the string?
- Arpad: That is already addressed
- Walter: Maybe we should allow NULL
- Small number of tools, large number of models
- It would be one less restriction for model makers
- The DLL deallocates all memory on Close
- Todd: Agree it's OK for simulators to ignore NULL pointers
- Curtis: This is a pointer to pointer
- The tool can write something back
- Todd: Should we set the pointer to zero?
- Walter: BIRD 128 says that
- Arpad: So input strings are non-NULL but output pointers can be
- Curtis: When we say optional it doesn't mean the function argument can be
left out
Arpad showed the Table BIRD draft:
- Radek asked to clarify the requirement for at least one template row for Usage out
- The size can be different between calls
- The entire table must be passed on each call
- Bob: Agree with this change
- Arpad: Can we vote?
- Ambrish: Would like one more reading
- Arpad: We will vote next week
Arpad showed the In/InOut BIRD
- Arpad: The sentences have been reorganized
- The only technical change is discussion of Usage Info
- Has restriction on affecting simulation results
- Walter: We agreed this would be 5.1+
- We have not defined what simulation is
- Scott: It included post-processing, necessary in statistical mode
- Walter: I will have something to discuss on this
- Would like to table this until then
- Arpad: We have a specific problem that this fixes
- This is version 10 of this BIRD
- Would like to finish it
- Bob: We did not decide on this specific issue in Open Forum
- Walter: We decided Friday this would go into 5.1+
- Bob: We didn't vote on that list
- Walter: It's OK if we can also address the Jitter BIRD, etc.
- Scott: Model_specific parameters have been used for post-processing because
they were not well defined
- We would also want to consider Jitter
- That could be in 5.1
- Bob: We may have to cut off some BIRDs for logistical reasons
- Scott: We can't go to 5.1 with things undefined
- Arpad: We discussed taking two steps
- Clarifications and reformatting would go into 5.1
- New features would go into 5.2
- One would follow the other quickly
- Scott: This BIRD has to be deferred to 5.1+ then
- It creates a loophole for post-processing
- Arpad: I would like to get this BIRD out of our group
- Walter: My presentation may make a difference
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Next meeting: 24 May 2011 12:00pm PT
Next agenda:
1) Task list item discussions
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IBIS Interconnect SPICE Wish List:
1) Simulator directives