Compaq 108164-003 - ProLiant - 800 Integration Notes page 25

PCI Bus Numbering in a Microsoft Windows NT Environment
Table 8. Test 1 – PCI BIOS bus detection in the ProLiant 8000
Bus
Detection
Order/
Controller
Discovery
1st
2nd
3rd
4th
5th
6th
7th
8th
9th
10th
11th
12th
13th
14th
Reviewing the Test 1 Configuration – Initial Configuration
Configuration B Test 1, illustrated in Table 8, provides an example of how the PCI BIOS
discovers controller devices and assigns bus numbers during the discovery process. As the PCI
BIOS moves through the bus detection order it looks for controller devices (not the slot numbers).
In this example, the PCI BIOS begins at the Host Bus and moves downstream assigning bus
numbers starting at bus 0 on the Primary Bus. In this scenario, no PCI devices reside on the
Primary bus, so the discovery process continues to the Secondary Bus by assigning 6 as the bus
number. The NC3131 in slot 5, a bridged device, is discovered next. The PCI BIOS assigns bus 7
to the PCI bus on the bridged controller, the last PCI controller discovered on the Secondary Bus.
13UK-1200A-WWEN
Slot PCI Bridge/
Number Controller Type
- Test 1
Primary Host to PCI
Bus (O) Bridge
Slot 1 Empty
Slot 2 Empty
Slot 3 Empty
Slot 4 Empty
Secondary
Host to PCI
Bus (6) Bridge
Slot 5 NC3131
Slot 6 Empty
Slot 7 Empty
Slot 8 Empty
Tertiary Host to PCI
Bus (13) Bridge
Slot 9 Empty
Slot 10 Empty
Slot 11 Smart Array
4250ES
Bus Number Description of PCI BIOS
Assignment Discovery Process
The PCI BIOS assigns 0 to
Bus 0 the Primary Bus and
continues downstream with
the controller discovery.
N/A
Slots 1-4 are empty, no PCI
bus number assignment.
N/A
N/A
N/A
The PCI BIOS discovers the
Bus 6
Secondary Bus and assigns it
bus number 6.
NIC in slot 5 contains a PCI
Bus 7
bridge and the PCI BIOS
increments the PCI bus
N/A
number to 7.
N/A
Slots 6-8 are empty, no PCI
bus number assignment.
N/A
The PCI BIOS discovers the
Bus 13
Tertiary Bus and assigns it
bus number 13.
N/A
Slots 9 and 10 are empty, no
PCI bus number assignment.
N/A
Intelligent drive array
controller with PCI bridge is
detected in slot 11. The PCI
Bus 14
BIOS increments the PCI
number to bus 14 and assigns
it to the bridge on the
controller.
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