IBIS Macromodel Task Group

Meeting date: 15 July 2014

Members (asterisk for those attending):
Agilent:                      Fangyi Rao
                            * Radek Biernacki
Altera:                     * David Banas
ANSYS:                      * Dan Dvorscak
                              Curtis Clark
Avago (LSI)                 * Xingdong Dai
Cadence Design Systems:     * Ambrish Varma
                              Brad Brim
                            * Kumar Keshavan
                            * Ken Willis
Ericsson:                     Anders Ekholm
Intel:                        Michael Mirmak
Maxim Integrated Products:    Hassan Rafat
Mentor Graphics:              John Angulo
                            * Arpad Muranyi
Micron Technology:          * Randy Wolff
                              Justin Butterfield
QLogic Corp.                  James Zhou
                              Andy Joy
SiSoft:                     * Walter Katz
                            * Todd Westerhoff
                            * Mike LaBonte
Synopsys                      Rita Horner
Teraspeed Consulting Group:   Scott McMorrow
                            * Bob Ross

The meeting was led by Arpad Muranyi.

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Opens:

- None

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Call for patent disclosure:

- None

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Review of ARs:

- None

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New Discussion:


BIRD 147.1 proposal from Bob Ross:

- Arpad: There was an email about a .1 version of this BIRD coming out.
- Bob showed BIRD 147.1_proposal3.txt
- Bob: This was sent last night.
  - It resulted from discussions with Ambrish.
  - The Formats in the BIRD were complex.
  - We adopted a different proposal similar to Walter Katz's proposal.
- Arpad: What was the reason?
- Bob: I objected to the complexity of the new formats.
  - The BCI rules where in two different sections.
  - The SiSoft proposal does the same thing without new formats.
  - This is close to that, but simplified.
- Bob described the new syntax.
- Mike: This is the first instance of reserved branch names.
  - Will parsers have trouble?
- Todd: Is this in the BCI File?
- Bob: Yes.
- Todd: How is this like the SiSoft proposal?
- Bob: It uses parameter hierarchy in a similar way.

- Ambrish: We have rules for branches on page 185.
- Bob: We have reserved branches in Protocol_Specific.
- Todd: But that is also a new proposal.
- David: If parsers are changed to handle that will it break them?
- Arpad: Can we have reserved branches in AMI today?
- Todd: Nothing in Model_Specific can be reserved.
- Ambrish: We can have rules specific to the BCI file.
- Mike: You could have Preamble_Bit_Pattern_Repeat.

- Bob showed 802.3KR_Rx.ami
- Ambrish: That is not from the SiSoft proposal.
- Todd: This new BIRD is not similar to the SiSoft proposal
- Bob: The nesting of branches is similar.
- Ambrish: Agree,this is not the SiSoft proposal.
- Arpad: Does Cadence agree with these changes?
- Ambrish: We thought Strings are strings and not really Bits.
  - We wanted to type it so models know what they are getting.
- Walter: Did you say the models read the training patterns?
- Ambrish: This is about Bits, not training patterns.

- Arpad: When will the BIRD arrive?
- Bob: Probably next week, Ambrish and I will work on it.

BIRD 128:

- Arpad: This is required for BIRD 147.
- Radek: There should be a separate API for BCI training.
  - This may change existing prototypes, but we need something better.
- Arpad: A new API is OK as long as it is justified.
  - An argument with an input flag is not good.
  - BCI should not be identified by InOut status.
- Radek: It's not just adding a parameter to GetWave.
  - It's adding a functional API.
- Ambrish: The change from Out to InOut can do anything, even outside of backchannel.
- Todd: AMI_GetWave doesn't already have that.
  - BIRD 128 is a back door means to avoid changing the footprint.
  - The other way is to change the footprint.
  - Radek has a good point.
- Ambrish: The change from Out to InOut should be enough.
- Arpad: It doesn't change the DLL function set.
- Todd: But it changes what the functions do.
- Ambrish: We could have a separate InOut argument.
- Arpad: It would be cleaner to have separate in and out parameters.
  - AMI_parameters_out is a ** pointer to pointer.
- Kumar: That is a standard practice.
- Todd: It is because the size of the return is not known.
- Arpad: How will memory be managed?
- Ambrish: A new pointer is assigned to the handle each time.
- David: Overwriting seems dangerous.
- Walter: The input parameter string has to be extracted and put into the output.
  - It's a new string created by the EDA tool.
- David: Will there be a handle that both the tool and model modify?
- Walter: The tool copies part of the string from the RX to pass to the TX.
- Todd: The RX returns a handle, the tool has no idea how much memory has been allocated.
- Walter: AMI_GetWave always allocates a new string to return, AMI_Close frees them.
- Radek: What if multiple copies of a TX are running?
- Kumar: Memory will never be overwritten.
- Walter: We handle that today.
  - Each DLL instance has it's own memory space.
  - They have to be re-entrant.
- Mike: If GetWave is called 10,000 times are the strings all freed in AMI_Close?
- Walter: I would free each one on the next call to GetWave
- Mike: Then we need to specify that each returned string is invalid after the next GetWave call.

- Arpad: We agreed last week that BIRD 147 should be self contained.
- Walter: I want BIRD 128 to be available for other purposes.
- Arpad: I don't mind keeping them separate.
- There were no objections.

- Mike: Does this change a pointer argument to a pointer to pointer?
- Kumar: It is already pointer to pointer.

- Radek: Does this conflict with the rule about passing at least a root name?
- Walter: That is for AMI_Init.
  - We need some rules here about what the string contains.
  - It should have a root with the name of the BCI file.
  - That allows the BCI and model root names to be mixed together.
- Kumar: Or BCI could be a branch.
  - Then other things could be passed in the future.
- Walter: All of this has to be very well documented.
- Arpad: Walter can you look into this?
- Walter: No, the authors have to do it.

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Next meeting: 29 Jul 2014 12:00pm PT

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IBIS Interconnect SPICE Wish List:

1) Simulator directives
