Specifications

Using Subcircuits 55
The corresponding Bus Port Connector to be used inside this device would
look as follows:
The comments above in the section, Port Pin Type, apply to each internal
pin in a bus pin. Remember that the name of the bus pin in the port connec-
tor is not significant.
Power and Ground Connections
Power and Ground symbols (for example, signal connector devices) do not
make a logical connection across subcircuit levels. For this reason, signal
connectors should not be used to make active signal connections for inter-
active simulation purposes.
They can be used to tie signals to high or low values, however, since it is
not relevant whether all tied–high signals are actually interconnected.
Creating a Subcircuit—Top–Down
To create a subcircuit top–down (for example, creating the subcircuit itself
after the parent symbol has already been used in a circuit), follow these
steps:
 Create the parent symbol using the device symbol editor. Be sure to set
the pin type (in/out/bidirectional) appropriately for each pin on the
symbol. (The Subcircuit / Part Type command does not normally need
Pin List (in symbol editor) Subcircuit Block Symbol
Pin List (in symbol editor) Port Connector Symbol
LW Reference.bk Page 55 Monday, December 15, 2003 5:59 PM