[ibis-macro] Re: SiSofts Official Position on BIRDS 116-125 ...

  • From: Taranjit Kukal <kukal@xxxxxxxxxxx>
  • To: "wkatz@xxxxxxxxxx" <wkatz@xxxxxxxxxx>, "'IBIS-ATM'" <ibis-macro@xxxxxxxxxxxxx>
  • Date: Fri, 11 Feb 2011 09:59:53 +0530

Hi Walter,
I have one comment on item 3). Why do we need special referencing to ISS 
Package Model - can't that be wrapped into Analog Buffer Model as subckt inside 
of Main subcircuit of Analog buffer?

As per BIRD125, Package model section would have reference to ISS package and 
that is the model to be used as default and if some if-then is required, then 
the model should be sub-model of main subcircuit in [EXTERNAL MODEL] and that 
would be covered by your item 2)

Am I missing something?

Rgds
..kukal


From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] 
On Behalf Of Walter Katz
Sent: Thursday, February 10, 2011 12:01 AM
To: 'IBIS-ATM'
Subject: [ibis-macro] SiSofts Official Position on BIRDS 116-125 ...

All,

After reviewing all of the discussion on BIRDS 116-125, I have come to the 
following conclusions

1.       Requiring the unity gain model inside ISS Analog Buffer models is 
acceptable to SiSoft. We will support any consensus within the ATM committee 
and the Open Forum.

2.       We will modify BIRD 122 to support the AMI file referencing ISS Analog 
Buffer Models directly.

3.       We will modify BIRD 122 to support the AMI file referencing ISS 
Package Models directly.

I think this is a good time to revisit a decision that was made three years ago 
about how AMI Models were referenced in the .ibs file. In review, a typical AMI 
section in an IBIS file might look like:

[Algorithmic Model]
Executable          Linux_gcc3.4.6_64           tx.linux64.dll      tx.ami
Executable          Linux_gcc3.4.6_32           tx.linux32.dll      tx.ami
Executable          Windows_VisualC++2008_32 sb_tx.win32.dll      tx.ami
[End Algorithmic Model]

Suppose instead the interface was

[Advanced Model]
AMI_File              tx.ami
[End Advanced Model]

And the .ami file had a reserved parameter "AMI_Model_Type", and the .ami file 
also contained reserved parameters that would have as values the names of the 
DLL files.

With this structure, one can simply declare new following new AMI_Model_Type 
values:
SerDes_Tx
SerDes_Rx
SerDes_Repeater_Rx
SerDes_Repeater_Tx
ISS_Tx
ISS_Rx
VHDL-AMS
Verilog-AMS
SPICE

And use the power of the .ami language to define the interface to the Model.

In short, we get around the issues of Typ, Min, Max and inability for IBIS to 
adapt to changing requirements by using the Advanced Modeling Interface as 
method of interfacing to the latest technologies, and we have a simple method 
of adopting as standard, by promoting the AMI parameters that define the 
interface to these new models as Reserved Parameters.

I think this approach is the correct one, and I think that the IC Vendor and 
System Design community that use IBIS models would recognize that this is the 
path for IBIS to become more relevant for the demanding needs of the users of 
models for non SerDes Algorithmic Models.

We will accept any consensus within the ATM committee and the Open Forum 
regarding defining the interface to package and buffer analog ISS subckts in 
the existing .ibs file, as long as it also supports the ability to make these 
interface definitions in the .ami file.


Walter



Walter Katz
wkatz@xxxxxxxxxx<mailto:wkatz@xxxxxxxxxx>
Phone 303.449-2308
Mobile 303.883-2120

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