Partners-in-crime --
In case my point escaped notice (I was rather obtuse about it), "supporting
a simulation or analysis type not defined or described in this
specification” is actually* NOT* the case we are trying to capture with the
BIRD, at least as I understand it. "Materially altering the results of
a simulation
or analysis type which is defined or described in this specification via a
mechanism which is not defined or described in this specification and thus
may not produce consistent results across EDA platforms conforming to this
specification" *IS* the Cornish pixie we are trying to tack down.
At least I *think* it is <grin>...
Regards,
Bob
On Wed, Sep 23, 2015 at 2:03 PM, Mike LaBonte <mlabonte@xxxxxxxxxx> wrote:
Hi Arpad,
Picking up on just one phrase “not defined or described in the IBIS
specification”, I think since it appears in the specification it would
say “not defined or described in this specification”.
Another question is if “simulation or analysis types not defined or
described” covers all of the cases we would want it to. For example, even
though IBIS requires that “algorithmic models must be able to produce
valid results at any sample_interval”, many do not. For these
non-compliant models it could be useful to have a parameter stating the
range or set of values that work, and tools could try to accommodate. But
would everyone interpret that as supporting a “simulation or analysis type
not defined or described in this specification”?
Mike
*From:* ibis-macro-bounce@xxxxxxxxxxxxx [mailto:
ibis-macro-bounce@xxxxxxxxxxxxx] *On Behalf Of *Muranyi, Arpad
*Sent:* Wednesday, September 23, 2015 3:04 PM
*To:* ibis-macro@xxxxxxxxxxxxx
*Subject:* [ibis-macro] Re: Out-InOut BIRD draft 12
Walter, Mike,
Here are the suggested texts I received from the two of you
(privately and publicly), and my version following them:
*WK:* This reserved parameter lists the Model_Specific parameter(s) *that
the model maker would like the EDA tool to use to affect simulation results*
.
*ML:* This reserved parameter *identifies the names of* Model_Specific
parameter(s) that rely *on EDA tool support for simulation types not
described in section 10.2.2*, and consequently may not be supported by
all EDA tools.
*AM:* This reserved parameter identifies by name all Model_Specific
parameters which require special EDA tool support to utilize special
features in the model, developed for simulation or analysis types not
defined or described in the IBIS specification, and consequently may not be
supported by all EDA tools.
Please let me know what you think of it…
What I like about my version is that it is “passive”, i.e. it
doesn’t mention model makers, EDA vendors, or who is expecting
or doing what, etc…, it just “states the facts”.
We might want to extend this language (and the features/syntax
of the new proposed reserved parameter) so that there would be
some indication for the level of deviation from standard behavior.
I still think that it should be useful to reveal whether the
Model_Specific parameter is either completely spec compliant
(green light), or whether it adds capabilities for new
analysis/simulation types without breaking the IBIS-standard
behavior of the model (yellow light) or whether it won’t work
at all unless the EDA tool supports its particular features
(red light).
I will address the text under Usage Rules and Other Notes later…
Thanks,
Arpad
==================================================================
*From:* Mike LaBonte [mailto:mlabonte@xxxxxxxxxx <mlabonte@xxxxxxxxxx>]
*Sent:* Tuesday, September 22, 2015 8:14 PM
*To:* Muranyi, Arpad; ibis-macro@xxxxxxxxxxxxx
*Subject:* RE: [ibis-macro] Re: Out-InOut BIRD draft 12
Hi Arpad,
True, I should not have written that In parameters *can’t* affect the EDA
tool; I subconsciously trivialized the possibility of that. And I’m not
saying anything necessarily new, just getting it out in writing for email
discussion.
We have a challenge here in that we usually try to make things easy for
model makers and users at the expense of tool developers, but in this case
we are talking about changes to allow tool developers to safely lead. It
might be going too far to have detailed info in AMI files on the impacts of
some parameters. But a simplistic ThereIsSomethingWrongWithTheseParameters
list might engender user perception problems, unless we clarify when model
makers should use it and what it means for the user.
So to simplify things we can first ignore scenario #2, the one that would
allow any tool to make use of special model capabilities. Yes, that would
be more complex and it might fall short anyway. So we are back to the list.
But if we will form a simple list of special parameters the rules should
be clear on why a particular parameter would want to be on the list. For
example models exist today with Out and InOut parameters that provide
simple diagnostic data should anyone want to see it. There would be no
reason to include those on the list, right? Yet if a tool decides to use
that data to accomplish something special then suddenly those parameters do
need to be on the list? But maybe if the output data has no effect on
ordinary simulation, that would except them from the list?
How about if we change:
“This reserved parameter tells the EDA tool which Model_Specific
parameter(s) rely on non-IBIS-standard features in the EDA tool, and
consequently may not be supported by all EDA tools.”
to:
“This reserved parameter identifies the names of
Model_Specific parameter(s) that rely on EDA tool support for simulation
types not described in section 10.2.2, and consequently may not be
supported by all EDA tools.”
The reason I eliminated “tells the EDA tool which” is to not imply in any
way that this must be used, since doing so could make existing IBIS
compliant models no longer comply (although they would still pass IBISCHK).
If we accept the proposal to use section 10.2.2 to define which parameters
would be candidates for the list, then maybe it could be called something
like SpecialSecenarioParameters or SpecialApplicationParameters or
LimitedSupportParameters, and 10.2.2 might even note “See GENERAL RESERVED
PARAMETERS for information about other simulation types with limited
support.” At the end of the first paragraph.
Mike
