Editing Interconnect Component Ports

The OpenBus Editor provides various features and commands for the manipulation of ports with respect to an Interconnect component. The following sections look at the management of ports for a placed Interconnect component – how they can be added and removed, and how they can be rearranged with respect to their order.

Port Addition/Removal

When you initially place an Interconnect component it will have a default number of ports – specifically one master port (m0) and one slave port (s0).

It is highly likely that you will have more than one I/O peripheral in your design, requiring connection to a processor through an Interconnect component. There may also be a series of slave memory devices that will be accessed by the processor, again through use of an Interconnect device. Such an Interconnect component will therefore have to be modified to have the correct number of ports.

To add a port, simply click on the button on the OpenBus toolbar (or use the Place » Add OpenBus Port command). A dimmed port shape will appear floating on the cursor. As you move the shape next to the perimeter of an Interconnect component, it will become solid – darker gray with a blue outline (Figure 1). Position the new port as required and click to effect placement.

Figure 1. Adding a port to an Interconnect component.

Ports can also be clustered into groups around an Interconnect component. Up to four cluster groups are possible (analogous to the four main points on a compass). To add a new port to an existing group, ensure you place the port directly next to an existing port in that group (Figure 2).

Figure 2. Clustering ports into groups.

To remove a port, simply click to select it in the workspace, then press the Delete key. The port will be removed from the Interconnect component, providing such removal is valid. Interconnect components must always have at least one master and one slave port, which cannot be removed.

Rearranging Ports

You may find, during the course of wiring up the OpenBus components, that certain ports could be better placed to ease wiring and make the system more readable. For an Interconnect component, you may want to cluster groups of ports differently after initial port addition. The OpenBus Editor provides the ability to change the location of a port (or ports) around a component.

To change the location of a port, simply click on the port and drag it to the required location on the perimeter of its parent component. Figure 3 illustrates this for an Interconnect component.

Figure 3. Rearranging ports around an Interconnect component.