Wiring up an OpenBus System

You've placed the required devices in your system, now it's time to wire up those devices.

In the schematic world, wiring between devices requires individual placement of wires and buses between corresponding pins of each signal in the interface. In some cases, interconnect (WB_INTERCON) and bus mastering (WB_MULTIMASTER) devices might need to be graphically reconfigured so that pins of interfaces line-up for nice parallel wiring. In other cases, the position of interface pins may make full wiring less than desirable and stub wiring with net labels is required.

In the OpenBus System, wiring is made very much simpler. The individual bus interface signals are not exposed, only a single port represents an interface. Two components are connected to each other using a single link, referred to as an OpenBus link. Links are made between ports of devices, with direction always being from a master port (red) to a slave port (green).

Links can be added by clicking on the button on the OpenBus toolbar (or by using the Place » Link OpenBus Ports command). A link is deleted simply by selecting it and pressing the Delete key.

When you enter link addition mode, all currently unlinked ports will be filtered, with all other elements in the system dimmed.

Figure 1. Component interfaces wired in a couple of clicks!

If you click to start a link on a master port, all currently unlinked slave ports will be filtered and available for choosing the termination point of the link. Conversely, if you click to start a link from a slave port, all currently unlinked master ports will be filtered and made available.

Note: You can start the link from either a master port or a slave port – the direction of the link itself will always be made to go from master to slave.

Rotate and/or flip OpenBus components in the system in order to facilitate easier linking of device ports and make the description of the system more readable.