which max/min model data for cor

I am trying to determine the correct methodology for extracting data from
IBIS models to simulate two corner cases: 1) flight time (slow/weak driver,
max. receiver load) and 2) signal quality (fast/strong driver, min. receiver
load).

I would like to present the following table for review.

---begin parameters

    IBIS Model Parameter Values Used to Simulate Flight Time and Signal Quality

    Device Modeling Parameter Flight Time Signal Quality
                                                 (Slow,Weak) (Fast, Strong)
    --------------------- ------------------ ----------- --------------
    Input Buffer Cpkg Max Min
                            Rpkg Max Min
                            Lpkg Max Min
                            Ccomp Max Min
                            PowerClamp Max Min
                            GroundClamp Max Min

    Output Buffer Ramp (dV/dt) Min Max
                            PullUp Min Max
                            PullDown Min Max
                            PowerClamp Min Max
                            GroundClamp Min Max
                            Ccomp Max Min
                            Lpkg Max Min
                            Rpkg Max Min
                            Cpkg Max Min

    Termination Rseries Max Min
                            Rgnd Max Min
                            Rpower Max Min
                            Rac Max Min
                            Cac Max Min

    Printed Circuit Board Zo Min Max
                            S (ns/ft) Max Min
                            Cvia Max Min

    Other Temperature Min Max
                            Vcc Min Max

    References:
    Intel AP-481 "Designing with the Pentium Processor, ..." October 1993
    I/O Buffer Information Specification (IBIS) Version 2.1, December 13, 1995
    UniCAD UniSolve Course Notes "Modeling for ... Signal Integrity", January 1997

    $Id: parameters,v 1.2 1997/07/16 18:26:34 welliott Exp welliott $
---end parameters

The following text from IBIS Specification Version 2.1 causes some confusion for
me (in particular the [Power Clamp] and [Gnd Clamp] keywords):

    "For most [Model] keyword data, the "min" column describes slow, weak
    performance, and the "max" column describes the fast, strong performance."

    "The voltage and temperature keywords ... control the conditions which
    define the "typ", "min", and "max" column entries for all V/I table
    keywords [Pulldown], [Pullup], [Gnd Clamp], and [Power Clamp]; ..."

My Four Questions:

 1) For an IBIS output model, do the "min" [Power Clamp] and [Gnd Clamp] keyword
    column data entries represent the slow/weak driver condition?

 2) For an IBIS input model, do the "max" [Power Clamp] and [Gnd Clamp] keyword
    column data entries represent the maximum receiver load condition?

 3) For the IBIS input model, like the one listed below, do the "max" [Gnd Clamp]
    keyword data entries correspond to the supply voltage of 5.5 volts, as
    indicated in the [Voltage Range] keyword?

---begin edo.ibs (portion)
|
[Model] INPUT
Model_type Input
Vinl = 0.8
Vinh = 2.4
|
|Variable typ min max
C_comp 1.5p 0.82p 2.99p
|
|Variable typ min max
[Voltage range] 5.0 4.5 5.5
|
[GND_clamp]
|Volts typ min max
-5.00 -127.0m -115.6m -140.4m
-4.00 -97.6m -88.3m -108.2m
-3.00 -65.8m -59.2m -73.5m
-2.00 -34.2m -30.8m -38.3m
-1.00 -5.78m -5.77m -5.92m
-0.800 -1.899m -2.17m -1.72m
-0.600 -0.714m -0.290m -0.465m
-0.400 -0.006m -0.0200m 0
-0.200 0 0 0
5 0 0 0
10 0 0 0
|
---end edo.ibs (portion)

 4) Is there a simulation methodology problem running a flight time simulation using
    IBIS model data for the driver corresponding to Vcc = 4.5 volts and the IBIS model
    data for the receiver corresponding to Vcc = 5.5 volts?

Thanks,

Wray Elliott, Engineer wray.elliott@scismail.sci.com
SCI Systems, Inc. MS/342 (205) 882-4107 Extension 3855
13000 S. Memorial Parkway
Huntsville, Alabama 35803

 
Received on Wed Jul 16 14:16:06 1997