[ibis-macro] Re: Summary and recomendations regarding Analog Buffer Modeling discussion (Tstonefile, ...)
- From: Taranjit Kukal <kukal@xxxxxxxxxxx>
- To: "wkatz@xxxxxxxxxx" <wkatz@xxxxxxxxxx>, IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
- Date: Thu, 8 Dec 2011 01:52:50 +0530
Hi Walter,
So BIRD144 had two main proposals:
1. Direct touchstone instantiation
2. User-defined corners for s-parameters
Looks like item 1) is being agreed upon so we need a comprehensive BIRD that
covers 116, 122 and 144 (item1) so it is not a total rejection of bird144 :)
Having said this, I personally do not agree with having a solution that is AMI
centric for s-parameter selection. BIRD144-item2 makes s-parameter usage more
generic and it would have allowed working with external circuit/model
with/without AMI. AMI file should be limited to parameters that c-code needs to
access and not get into pointing to those files that represent buffer portions
that have nothing to do with c-code ....but then I leave this to decision of
ATM group
cheers
..kukal
________________________________
From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx]
On Behalf Of Walter Katz
Sent: Wednesday, December 07, 2011 10:48 PM
To: IBIS-ATM
Subject: [ibis-macro] Summary and recomendations regarding Analog Buffer
Modeling discussion (Tstonefile, ...)
All,
First I will review various features of BIRDS 116, 122, and 144, and then make
several recommendations.
For [Model]s that have an AMI model
Tstonefile
BIRD 116 requires an ISS subckt file containing an S element instance, and
requires parsing a number of lines in the [External Model] section to determine
what is defined the BIRD 122 AMI parameters Tstonefile, Nodemap, Voh, Vol, Trf.
Equivalent-Circuit Rx and Tx defined in BIRD 122
The Equivalent-Circuit Rx and Tx defined in BIRD 122 accurately represent the
differential response of legacy IBIS models that have a constant differential
impedance and do not have VT curves (i.e. Use dV/dt_r and dV/dt_f instead of
VT curves). This includes Series Pin and Termination models. (The
Equivalent-Circuits will need to be enhanced to include some inductors).
Differential ISS subckts.
Both BIRD 122 and 116 enable a model to define an File and Subckt for a
Differential ISS subckt.
For [Model]s that do not have an AMI model
BIRD 116 allows the user to use an ISS subckt to represent the Analog Model
Recommendations
Enhance BIRD 116 to allow the following Languages, and keywords for each
language (keyword names and syntax TDB)
Touchstone
Tstonefile
Nodemap
Vol
Voh
Trf
Generic_Tx
Vol
Voh
Trf
Rs
Rd
Rt
Cd
Cc
Rac
Cac
Ls
Lt
Ld
Generic_Rx
Rd
Rt
Cd
Cc
Rac
Cac
Lt
Ld
ISS
As defined in BIRD 116
BSS
This is same as ISS, except the subckt is compliant with IBIS Buffer Spice
Subckt (IBIS BSS). IBIS BSS is a superset of IBIS ISS. IBIS BSS contains
additional elements, such as PWL controlled sources, event detectors, and
timers. IBIS BSS subckt can be written to be equivalent to a compliant legacy
"B" element.
Approve both BIRD 122 and 116 (or combine them into a single BIRD, so that AMI
model developers can put Tstonefile, Equivalent-Circuit Rx and Tx, and
Differential ISS subckts in either the .ami file and or the .ibs file
Reject BIRD 144
Walter
Walter Katz
wkatz@xxxxxxxxxx<mailto:wkatz@xxxxxxxxxx>
Phone 303.449-2308
Mobile 720.333-1107
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