User Guide

Chapter 10 Preparing Your Design for Board Layout
296
Parts List Mapping (.xmp)
After PSpice Schematics has found a matching rule in the
map file for the
COMPONENT or PART attribute of a part, it
further processes the replacement string. This processing
is similar to the processing of the
TEMPLATE attribute of a
part when a simulation netlist is created. Identifiers in the
string prefixed by one of the characters ‘@,’ ‘?,’ ‘~,’ ‘#,’ and
‘`’ are treated as part attribute names. A simple example
would be a string such as
@PART—this is replaced by the
value of the
PART attribute. An error occurs if the PART
attribute is not defined.
When the ‘ `’ (backquote) character precedes a ‘@,’ ‘?,’ ‘~,’
or ‘#’ character, it acts as a modifier. It causes the mapped
value of an attribute (looked up in the .
xpk file) to be used
instead of the attribute value itself. For example,
`@PKG
would be replaced by the value of the PKG attribute,
mapped by any matching rule in the .xpk file.
Examples
1 Capacitors
We need to be able to provide for a generic capacitor
(where the designer has not provided any information
beyond the capacitor’s value and possibly a tolerance),
and also for a more specialized capacitor (where the
designer supplies the exact package type as well as the
component value and tolerance).
To support the simple case, a rule of the following form
will be required in the
.xpk file:
CAP CAP,@value?tolerance|,@tolerance|
C AKO CAP
These rules will match a part with a COMPONENT or PART
attribute with a value of CAP or C. They will produce
entries in the Part list like: