Specifications

38 Chapter 3—Advanced Schematic Editing
Bus Operations
Creating a Bus
A bus can be created by any one of the following methods:
 Select the Draw Bus tool ( ) in the Tool Palette. Draw any desired
contiguous set of lines on the diagram using the usual signal drawing
techniques. This bus will have no internal signals initially. Signals will
be added implicitly when it is connected to any breakout or bus pin.
 Create a breakout symbol using the New Breakout command (see
below). The bus pin (backbone) of the breakout can now be extended
using the normal pointer ( ) or the Draw Bus cursor. The bus will
contain all signals specified in the breakout.
 Extend a line out from an existing bus pin on a device (see below)
using the normal pointer or the Draw Bus cursor. The bus will contain
all signals specified in the bus pin on the device. Connections between
bus internal pins and bus internal signals can be changed using the Bus
Pin Info command on the bus pin’s pop–up menu.
Adding Signals to a Bus
There is no explicit command to add signals to a bus. Signals are added to a
bus each time a breakout or device bus pin is connected to the bus. Any sig-
nals in the breakout or bus pin are implicitly added to the bus if they don’t
exist already.
Creating a Breakout
To create a breakout, select the New Breakout command in the Schematic
menu. If the new breakout is to be similar to an existing one, first select the
similar breakout or the bus to which the new breakout is to be connected.
B
us Connection Points
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