Product specifications

Extended Daisy-Chain Configuration
In this case, the bus labeled (Bus 6) is obviously further downstream
(hierarchically speaking) than the bus labeled (Bus 4). And, of course,
there is a caveat to all of this: the bus numbering depends on the
algorithm implemented by your BIOS or console firmware configuration
code. We have labeled everything here as if:
a) The BIOS or firmware runs a true "depth-first" search of
the PCI bus hierarchy
b) Your BIOS or firmware will actually deal with multiple
PPBs.
Fan-Out
In a fan-out configuration, successive PCI expansion systems are
added to the PCI bus hierarchy at a "peer" level of other existing
expansion buses, thus adding "breadth" to the PCI bus hierarchy since
these buses will be at the same hierarchical level within the system
configuration.
Fan-Out Configuration
The PCI Local Bus in your host computer will typically be numbered as
"PCI Bus Zero". Each addition of a PPB to the bus hierarchy will add a
new bus level into the hierarchy. In the following discussion, higher PCI
Local Bus numbers are termed to be "downstream" of lower numbered
buses. Similarly, lower numbered buses are termed to be "upstream" of
higher numbered buses.
Each PPB has a primary side (which is attached to the "upstream" or
lower numbered PCI bus), and a secondary side (which is attached to