Connectivity

This section lets you specify the nets for which you want to create a bus and optionally lets you create a probe for the specified net.

Net Name

Specifies the net names for creating a bus. You can specify the net names separated by commas or spaces or specify them in bus notation, such as net<0:3>. New nets are created if the ones specified do not already exist. If you start creating a bus from existing pins, the net names are automatically picked from the net of the pins.

Environment variable: netName

Probe Nets

Creates probes for the autopicked, selected, or specified nets.

This section lets you specify the width, direction, and style for the wire that you want to create.

All Nets Width

Specifies the width of each wire in the bus. You can increase or decrease the wire width by pressing Ctrl + Shift keys and scrolling the mouse wheel up or down, respectively.

Environment variable: wireWidth

All Nets Bit Spacing

Specifies the distance between the centerlines of the bus wires. If no value is specified in this field, the minSpacing value is considered.

Fan Out to Vias

Spreads bus wires for via placement. When wires are at the minimum wire spacing but the via spacings are larger, the wires can either be fanned out to connect to the vias in the pattern or can be back tracked to intersect the previous segment in the wire.

Environment variable: fanOutToVias

Create Bus Constraint

Creates a bus constraint automatically, if one does not already exist, for the nets you specify in the Net Name field or for the ones you pick by area-selecting multiple pins or instPins. You can view the created bus constraints in the Constraint Manager in Layout XL and higher tiers.

Environment variable: weCreateBusConstraint

Number of Bits

Lets you specify the number of wires in an unassigned bus. The default value is 2.

• In the Net Name field, if you specify net names as a bundle name or by using the bus notation, the value in the Number of Bits cyclic field automatically updates to match the number of nets specified. If net names are specified in the Net Name field and you manually update the value in the Number of Bits cyclic field, the net names specified in the Net Name field are removed.
• In the Net Name field, if you specify the net names by using the bus base name, you can set up the cardinality of the bus by using the Number of Bits cyclic field. The bus base name expands to display individual net names in the Net Name field only after you start creating the bus.
• If you update the Number of Bits cyclic field after starting bus creation, the net names are removed from the Net Name field.
• If you change the number of bits from the default value, which is 2, to any other value, and then specify the net name, the number of bits does not get reset to default value 2. The last changed value is retained in the Number of Bits cyclic field.

Environment variable: weBusNumBits

Justification

Controls the direction in which to offset the pathSeg from the digitized points. The supported routing directions include center, left, and right. The default is center.

Environment variable: pathJustify

Offset

Creates wire at a specified distance from the digitized points with respect to the centerline of the pathSeg, in the direction specified by Justification. The default is 0.

Environment variable: wireOffset

Begin Style

Controls how the beginning wire segment ends are created.

• auto: Automatically sets the begin style of the wire.
  • When the wire is Manhattan in shape, its Begin Style is set to truncate.
  • Two orthogonal Manhattan wires will have their Begin Style and End Style set to extend to avoid notches.
  • When the wire is diagonal in shape, its Begin Style is set to custom.
  • Two diagonal orthogonal wires will have their Begin Style and End Style set to custom to avoid notches.
• truncate: Creates a wire with no begin extension.
• extend: Creates a wire with the default begin extension value.
• variable: Lets you override the value specified in the Begin field for the begin extension of a wire.
• custom: Constraints the vertices of the created wire to the current grid.

The default value is auto.

Environment variable: pathSegBeginStyle

Begin

Specifies the value for the begin extension of the wire. This field is enabled when Begin Style is set to variable.

Environment variable: pathSegBeginExt

End Style

Controls how the beginning wire segment ends are created.

• auto: Automatically sets the end style of the wire.
  • When the wire is Manhattan in shape, its Begin Style is set to truncate.
  • Two orthogonal Manhattan wires will have their Begin Style and End Style set to extend to avoid notches.
  • When the wire is diagonal in shape, its End Style is set to custom.
  • Two diagonal orthogonal wires will have their Begin Style and End Style set to custom to avoid notches.
• truncate: Creates a wire with no begin extension.
• extend: Creates a wire with the default begin extension value.
• variable: Lets you override the value specified in the Begin field for the begin extension of a wire.
• custom: Constraints the vertices of the created wire to the current grid.

The default value is auto.

Environment variable: pathSegEndStyle

End

Specifies the value for the end extension of the wire. This field is enabled when End Style is set to variable.

Environment variable: pathSegEndExt

The following options let you specify the snapping behavior for the bus that you want to create.

Snap Mode

Controls how the cursor snaps when you create a bus.

• diagonal: Creates wires parallel to the X or Y axis or at a 45-degree angle to the axes.
• orthogonal: Creates wires parallel to the X or Y axis.
• L90XFirst: Creates orthogonal two-segment wires and creates the first line in the X direction.
• L90YFirst: Creates orthogonal two-segment wires and creates the first line in the Y direction.

The default value is orthogonal.

Environment variable: snapMode

Snap to Pin Center

Snaps the bus wires to the center of rectangular pins or of pins that are created as polygons and have rectangular shapes. When this check box is selected, bus wires snap to the starting and ending pins centers. By default, the Snap to Pin Center check box is not selected.

Environment variable: snapToPin

Auto Terminate

Finishes the Create Bus command as soon as a point is digitized on a flightline target object (pin, existing wire, or via). All wires in the bus snap to the target pin. This option is selected by default.

Snap to Via Center

Snaps wires to the center of vias. If this check box is selected and you click a via, the starting wire starts from the clicked point and two small segments are added to connect to the via origin. With this check box selected, tapping a via and a wire gives preference to the via. This check box is off by default.

Environment variable: snapToViaCenter

Cover Pin

Adjusts the wire segment to automatically cover the source and target pins. Otherwise, the wire segment is not adjusted and the wire terminates at the point you chose. By default, this option is deselected.

Environment variable: weCoverPin

Custom Layer Pattern

Enables or disables the feature to specify a multi-layer pattern.

The Custom Layer Pattern combo box lets you specify a multi-layer pattern or select an existing multi-layer pattern. For more information, seeCreating a Multi-Layer Bus from an Empty Space.