There are several ways that the host PC and the TIMs can exchange data. By far the simplest and most convenient is by using ComPorts. A ComPort can be thought of as a data pipe: the transmitting processor pushes words in at one end and the receiving processor pulls them out of the other. Each ComPort can support transfers in both directions at once.
ComPorts are used to communicate between pairs of TIMs. A special comport, the host comport, is used for communication between the host PC and the first TIM in your system (the root TIM).
You can connect ComPorts together using external cables on the back of the carrier board or internal wires that are built into it.
The host ComPort uses your PC’s PCI bus. Simply plugging the carrier board into the PC establishes this connection.
The host PC needs to be able to communicate with your carrier board. It does this by making use of a device driver - software provided by Sundance that runs on the host and understands how to transfer data over the host ComPort.