OpenBus Components Palette
The starting point for any OpenBus System document is the placement of the required devices that will consitute your system. In the schematic world, design components reside in libraries and are placed on the sheet directly from the Libraries panel. In the OpenBus Editor, the corresponding OpenBus components are placed from the OpenBus Palette panel (Figure 1).
Figure 1. Place design primitives for your OpenBus System from the
OpenBus Palette panel.
The panel contains graphical representations of all devices available for use in creating the system, grouped into the following four categories:
- Connectors – provides Interconnect and Arbiter components that are functionally similar to the WB_INTERCON and WB_MULTIMASTER devices in the schematic world. Additional components allow for bus interface signals to be exposed outside of the OpenBus System document. A termination port is also provided for occasions when a master port is not being used and should be terminated properly.
- Processors – provides all of the 32-bit processors supported by Altium Designer.
- Memories – provides memory controller devices.
- Peripherals – provides all of the I/O peripheral devices available for design.
Should you wish to view more information about a particular component, simply hover the cursor over its entry and a more detailed description will be displayed in the lower region of the panel.
If the processor, peripheral and memory components are the 'bricks' of the system, the Interconnect and Arbiter components can be thought of as the 'mortar' that brings them together. It is worth spending a moment to look at the role of these two components, and why you would want to use them in the first place.
The Role of the Interconnect Component
The Interconnect component provides a means of accessing one or more peripheral devices over a single OpenBus interface. It connects directly to the IO or MEM ports of a processor component, facilitating communication with I/O peripherals or physical memory devices, respectively.
The Role of the Arbiter Component
The Arbiter component provides a simple means of sharing a slave peripheral device between multiple masters within the OpenBus System. Typically, it is used where two or more devices require access to shared physical memory – for example two or more processors, or a processor and memory-based peripherals, such as a VGA Controller or a BT656 Video Capture Controller.