A Differential Pair is a design directive that allows design specifications to be associated with a net-type object within a schematic design. Differential pairs include the pre-defined parameter named DIFFPAIR which enables the software to recognize this and displays the object as a differential pair directive.
Differential Pairs are available for placement in the schematic editor in the following ways:
- Choose Home | Circuit Elements | Directives » Differential Pair from the main menus.
- Right-click in the design space then click Place » Directives » Differential Pair from the context menu.
A differential pair can be used to attach parameters to a Wire, Bus, Signal harness, and Sheet Symbol.
After launching the command, the cursor will change to a cross-hair and you will enter the design directive placement mode. Placement is made by performing the following actions:
- Position the cursor over a wire or other net object and click or press Enter to place.
- Continue placing further directives or right-click or press Esc to exit placement mode.
Additional actions that can be performed during placement – while the parameter set is still floating on the cursor are:
- Press the Tab key to pause the placement and access the Differential Pair mode of the Inspector panel, from where its properties can be changed on the fly. Click the design space pause button overlay () to resume placement.
- Press the Alt key to constrain the direction of movement to the horizontal or vertical axis, depending on the initial direction of movement.
- Press the Spacebar to rotate counterclockwise or Shift+Spacebar for clockwise rotation. The action can also be performed while dragging the object. Rotation is in increments of 90°.
- Press the X or Y keys while in placement mode to flip the parameter set along the X-axis or Y-axis.
This method of editing allows you to select a placed parameter set directive directly in the design space and change its location or orientation graphically.
When a differential pair directive is selected in the design space, a dashed box will appear around the directive. The box encloses the area occupied by the directive only. For each visibility-enabled member parameter of the set, a dashed line will be visible, connecting the text field of the parameter to the body of the directive, which affirms association.
Click anywhere inside the dashed box then drag to reposition the differential pair as required. While dragging, the differential pair can be rotated (Spacebar/Shift+Spacebar) or mirrored (X or Y keys to mirror along the X-axis or Y-axis).
This method of editing uses the Inspector panel mode to modify the properties of a differential pair object.
During placement, the Differential Pair mode of the inspector panel can be accessed by pressing the Tab key. Once the parameter set is placed, all options appear.
After placement, the Differential Pair mode of the Inspector panel can be accessed in one of the following ways:
- Double-clicking on the placed differential pair object.
- Placing the cursor over the differential pair object, right-clicking then choosing Properties from the context menu.
Editing Multiple objects
The inspector panel supports multiple object editing, where the property settings that are identical in all currently selected objects may be modified. When multiples of the same object are selected manually in the design space, the Inspector panel field entry that is not shown as an asterisk (
*) can be edited for all selected objects.