BIRD31.2 - Mated Models

Hello Bob:

     A quick comment on the Tedge_rate parameter. I think the allowable
values for Tedge_rate should also include 'NA' - not available. If the
information is not available, I feel it should be stated explicitly, not by
entering a value of zero. Anyway, that is my preference.

                   Regards,
                   Stephen Peters
                   Intel Corp.

>>>> excerpt for BIRD follows follows

|==============================================================================
| Keyword: [Define Package Model]
| Required: Yes
| Description: Marks the beginning of a package model description.
| Usage Rules: If the .pkg file contains data for more than one package,
| each section must begin with a new [Define Package Model]
| keyword. The length of the package model name must not
| exceed 40 characters in length. Blank characters are
| allowed. For every package model name defined under the
| [Package Model] keyword, there must be a matching [Define
| Package Model] keyword.
|------------------------------------------------------------------------------
[Define Package Model] QS-SMT-cer-8-pin-pkgs
|
|*=============================================================================
|* Keyword: [Define Mated Model]
|* Required: Yes
|*2 Sub-params: Tedge_rate, Cpad_1, Cpad_2
|* Description: Marks the beginning of a mated model description.
|* Usage Rules: If the .mmf file contains data for more than one mated model,
|* each section must begin with a new [Define Mated Model]
|* keyword. The length of the mated model name must not
|* exceed 40 characters in length. Blank characters are
|* allowed.
|*
|*2 The Tedge_rate is as a required subparameter defining the
|*2 the minimum time edge rate for which the mated model is
|*2 considered accurate under test fixture conditions. A more
|*2 detailed mated model topology would be preferred if the edge
|*2 rate were smaller. The Tedge_rate subparameter may serve
|*2 to produce a warning that the simulations are being done
|*2 outside of the mated model performance range.
|*2
|*2 A numerical value must be defined. It is the input pulse
|*2 rise time defined between the 20% and 80% points.
|*2 This value will be the minimum value where the signal line
|*2 "impedance" is within 10% of the simulated impedance. This
|*2 impedance parameter is the dynamic ratio at the mated model
|*2 input voltage to input current over time under the condition
|*2 that the signal line has a source and load termination of
|*2 of 50 ohms and all other lines are grounded. A value of 0
|*2 is permitted, and would serve as an indication that no
|*2 performance limit is available. However, if the model is
|*2 suitable for all edge rates, use a very small, non-zero
|*2 value such as 1e-15 seconds.
|*2
|* The Cpad_1 and Cpad_2 subparameters are optional and define
|* default pad capacitances at sides 1 and 2 of the mated model.
|* The values default to 0 pF if omitted. However, in all cases
|* the simulator may override the default values based on
|* actual geometrical pad dimensions.
|*2
|*2 Other Notes: The mated model extends to the physical surfaces of the
|*2 structure in the mated configuration. For example, the
|*2 the printed circuit board fingers of an edge card connector
|*2 that extend into the connector are included in the mated
|*2 model electrical description. The Cpad_1 and Cpad_2 sub-
|*2 parameters are optional default extensions for pads outside
|*2 the mated model physical dimensions.
|*------------------------------------------------------------------------------
Received on Mon Apr 29 13:06:27 1996