Specifications

172 Chapter 8—Device Symbol Editing
from the circuit definition.
Creating a Breakout
A breakout is a special device that allows signals to be associated with a bus. It
consists of 1 Bus pin, no internal pins, and N normal pins. Because the device
type is breakout the normal pins will be connected to like named signals in the
bus. Breakouts are normally created using the New Breakout command
described in “Creating a Breakout” on page 38.
NOTE: Another way to split signals out of a bus is to use a part with a subcircuit as a
splitter, which explicitly routes signals between pins. This has advantage of flexibility
since signals do not have to be explicitly broken out but may instead be split into
busses or any combination of busses and signals. The disadvantage is that since
the splitter is a device it will be listed in hierarchical netlists. In flattened netlists it will
not appear if marked as a non-protected device. In addition, there is a significant
memory and file size penalty.
Creating a Power and Ground (Signal) Connector
A power or signal connector is a special type of device which is generally used
to represent a power or ground source, e.g.: +5V, +15V, -15V, -5V, Ground,
Vss., Vdd.
These devices have a special properties in the schematic. When a pin on one of
these devices is connected to a signal it attempts to assign its pin name to the sig-
nal. If the signal doesn't have a name then it gets the name of the pin. If the sig-
nal is named, and the name is different from the pin's name, then you will be
prompted to select between the signal name and the pin name.
An additional property of signal connectors is that any signal they are connected
to is exported across all pages of the schematic.
Power and Ground Connections with the LogicWorks
LW Reference.bk Page 172 Monday, December 15, 2003 5:59 PM