What are HyperTransport hosts, caves, tunnels and bridges?
HyperTransport links interconnect HyperTransport devices in a daisy-chain topology. Each HyperTransport link must have both a host that acts as a HyperTransport link(s) master and an endpoint device, or cave. Additional HyperTransport devices need to be of the tunnel type and they are inserted in the daisy-chain link between the host and the cave. If a HyperTransport link needs to be connected to another type of I/O interconnect standard, a bridge device is required to… bridge the two interconnects, as in the case of a bridge controller interfacing HyperTransport to PCI Express. Tunnels and bridges can act as link endpoints or cave devices also. Each HyperTransport link can support up to 32 HyperTransport controllers (inclusive of host, cave, tunnels and bridges). For more information on host, cave, tunnel and bridge functions, please refer to the HyperTransport white papers and the HyperTransport Bridge Functions overview.
