[ibis-macro] Re: AMI Corner, and IBIS C_Comp, one more time

  • From: "Muranyi, Arpad" <Arpad_Muranyi@xxxxxxxxxx>
  • To: IBIS-ATM <ibis-macro@xxxxxxxxxxxxx>
  • Date: Thu, 13 Oct 2011 22:58:24 +0000

Walter,

If I would summarize this, you are basically saying
that for I-V and V-t curves IBIS_min = AMI_slow and
IBIS_max = AMI_fast and for C_comp either the tool
or the user can decide what they pick for AMI_slow
and AMI_fast.  And once C_comp_corner (or anything
similar) is available in the spec, that new parameter
will take care of this by having the proper definition
for IBIS_slow and IBIS_fast (which doesn't exist today).

It seems that this would solve the "align implicitly to slow
and fast corners" in the AMI specification, because it
provides a definition for an AMI Format Corner parameter
to be associated with the EDA tool's analog model corner.

But this still leaves the ambiguity open about which
C_comp value (min/max) should be used with AMI_slow and
AMI_fast.  You might say that AMI models do not use
analog models with C_comp anyway, but there are quite a
few non-Opal (i.e. IBIS compliant) IBIS-AMI models out
there for which it would be nice to know how these
associations should be made...  My proposal spelled out
what the association is with the current C_comp as well
as the 5-corner version of C_comp (whether it goes with
my syntax or Bob's is just another small detail).

Thanks,

Arpad
=============================================================




From: ibis-macro-bounce@xxxxxxxxxxxxx [mailto:ibis-macro-bounce@xxxxxxxxxxxxx] 
On Behalf Of Walter Katz
Sent: Wednesday, October 12, 2011 10:29 AM
To: IBIS-ATM
Subject: [ibis-macro] AMI Corner, and IBIS C_Comp, one more time

All,

I think AMI format Corner is well understood, although one could change the 
following lines:


| Note that in the context of Algorithmic Model for type 'Corner', <slow

| value> and <fast value> align implicitly to slow and fast corners, and

| <slow value> does not have to be less than <fast value>. For type 'Range'

| and 'Increment', <min value>, <max value> does not imply slow and fast
| corners.

To say,

Note that in the context of Algorithmic Model for format Corner, <typ value> 
<slow value> and <fast value> shall be the values used when the IBIS Analog 
Model that is being used to generate the Impulse Response of the channel shall 
use the IBIS analog model that corresponds to the derivation methods as 
described for typical, slow-weak and fast-strong respectively in section 9 of 
IBIS.

For C_comp (where C_Comp_Used is the value used in the simulation):

*         If an IBIS model has just C_comp the User/EDA tool shall choose a 
value of C_Comp_Used from the values of C_comp when simulating typical, 
slow-weak, or fast-strong IV and VT data. Although it is common practice (but 
not required) to use the min value of C_comp for fast-strong IV and VT data and 
C_comp max for slow-weak IV and VT data.

*         If a model has C_comp and C_comp_corner, then the User/EDA tool shall 
choose either a value of C_Comp_Used from the values of C_comp in accordance 
with the previous paragraph, or use the typ, min, max value of C_comp_corner 
when simulating typical, slow-weak, or fast-strong IV and VT data respectively.

This defines a default method of defining C_Comp_Used when C_comp_corner is not 
defined and when C_comp_corner is defined.  C_comp_corner is defined the User 
can direct the EDA tool to use the values of C_comp_corner that correspond to 
the derivation methods of the IV and VT tables, or use the values of C_comp 
either correlated or independent of the IV and VT tables used.

Walter

Walter Katz
wkatz@xxxxxxxxxx<mailto:wkatz@xxxxxxxxxx>
Phone 303.449-2308
Mobile 720.333-1107

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