User Guide

Configuring model libraries
121
• Add as Global for global models.
How PSpice uses model libraries
PSpice searches libraries for any information it needs to
complete the definition of a part or to run a simulation. If
an up-to-date index does not already exist, PSpice
automatically generates an index file and uses the index to
access only the model definitions relevant to the
simulation. This means:
• Disk space is not used up with definitions that your
design does not use.
• There is no memory penalty for having large model
libraries.
• Loading time is kept to a minimum.
Search order
When searching for model definitions, PSpice scans the
model libraries using these criteria:
• design model libraries before global model libraries
• model library sequence as listed in the Libraries tab of
the Simulation Settings dialog box
• local directory (where the current design resides) first,
then the list of directories specified in the library
search path in the order given (see Changing the library
search path on page 4-125)
Caution—When you use
include files instead
PSpice treats model library and include files
differently as follows:
•
For model library files, PSpice reads in
only the definitions it needs to run the
current simulation.
•
For include files, PSpice reads in the file
in its entirety.
This means if you configure a model library
(*.LIB extension) as an include file using
the Add to Design or Add as Global button,
PSpice loads every model definition
contained in that file.
If the model library is large, you may
overload the memory capacity of your
system. However, when developing
models, you can do the following:
1 Initially configure the model library as
an include file; this avoids rebuilding
the index files every time the model
library changes.
2 When your models are stable,
reconfigure the include file containing
the model definitions as a library file.
To reconfigure an include file as a library
file:
1 From the Simulation menu, choose Edit
Simulation Settings, then click the
Include Files tab.
2 Select the include file that you want to
change.
3 Click either the Add as Global or the
Add to Design button.
4 Click Remove to remove the include file
entry.
Pspug.book Page 121 Wednesday, November 11, 1998 1:14 PM