RE: BIRD #61

Richard,

If the waveform is linear, than the change in delay delta_Td
as a function of Slew_rate is sufficient to calculate switching moment,
provided the 'base delay', Td, is either unimportant or provided by user.

If we still consider linear waverorms, than tables for
delta_Td as function of Start_Point (End_Point,Slew_rate are constant) and
delta_Td as function of End_Point (Start_Point,Slew_rate are constant)
do not contain much information, just a linear increase (or decrease)
in the rising (or falling) time. This effect can be accounted for
without any table.

If the waveform is nonlinear, than dynamic thresholds dyna_Vinh (2 go to hi)
and dyna_Vinl (2 go 2 low) would be helpful. They should be consistent with tables
in that dyna_Vinh is that voltage in linear rising WF at which delta_Td=0,
similarily, dyna_Vinl is such voltage for linear falling WF,
for which the table gives delta_Td=0.
Would be valuable to have dyna_Vinh - dyna_Vinl > a few kT/e .

Nik

nikolai@avanticorp.com

:-) From owner-ibis@server.eda.org Tue Aug 24 21:53 PDT 1999
:-) From: "Mellitz, Richard" <richard.mellitz@intel.com>
:-) To: "'ibis@eda.org'" <ibis@eda.org>
:-) Subject: RE: BIRD #61
:-) Date: Tue, 24 Aug 1999 21:03:14 -0700
:-) MIME-Version: 1.0
:-)
:-) The goal is to model behavior. Are the tables sufficient for some limited
:-) problem space?
:-)
:-) Simply put: Can simulator vendors use this data to drive their algorithms?
:-)
:-) It doesn't, a priori, require the simulator to use a particular method.
:-) Regarding a "functional" implementation the question would be: "Can these
:-) tables be used to load the function's algorithms?" Another simulator may
:-) choose a more direct approach that detects slew rate. Each will have its
:-) advantages which allows simulator vendors to differentiate on.
:-)
:-) To rephrase the question: "Have we provided enough information for the
:-) implementation of an acceptable variety of receiver modeling methodologies?"
:-)
:-)
:-) Richard Mellitz
:-) Intel
Received on Wed Aug 25 18:45:28 1999