Specifications

Using Subcircuits 53
The port interface is rechecked whenever any change is made. Thus, as
soon as a port connector is added or removed, or its name is changed, the
port interface will be updated to reflect the new logical connections. How-
ever, to avoid excessive warning messages, error checking is performed
only when an internal circuit is opened or closed. A warning box will be
displayed if any error is found. This checking cannot be disabled.
NOTE: The name of the port connector’s pin and the name of the signal attached
to the port connector are not significant in making the port association.
Only the contents of the port connector’s Name field are used. Note the
different rules for bus ports below.
Port Pin Type
In order for the simulation of a subcircuit device to operate correctly, the
type of port connector symbol used in the subcircuit must match the type of
pin on the parent device symbol, according to the following table:
*
For Tied High, No Connect, and other pin types, use a Port In for consistency
—although no simulation data is transferred through these types of pins in any
case.
Parent Pin Type Port Connector (in the connect.clf library)
Input Port In
Output Port Out
Bidirectional Port Bidir
Bus Must be custom–made
All others
Port In
*
LW Reference.bk Page 53 Monday, December 15, 2003 5:59 PM