PCI Bus Numbering in a Microsoft Windows NT Environment

PCI Bus Numbering in a Microsoft Windows NT Environment 49
13UK-1200A-WWEN
IMPORTANT: The controllers that Compaq added to the server configuration were selected
only to illustrate how bus renumbering occurs. Several different SMART Array and network
controllers were included to demonstrate that they all respond to renumbering in the same
manner. This is not meant to be a recommended configuration.
Test 2 in Table 16 illustrates how bus assignments change when physical configuration changes
occur in the server.
Table 16. Test 2 – PCI BIOS bus detection in the ProLiant 6000 and 7000 servers
Bus
Detection
Order/
Controller
Discovery
Slot
Number
PCI Bridge/
Controller
Type - Test 2
Bus Number
Assignment
Description of PCI BIOS Discovery
Process
1st
Primary
Bus (0)
Host to PCI
Bus bridge
Bus 0
2nd Slot 1
(EISA)
N/A
N/A
3rd Slot 2
(EISA)
N/A N/A
4th Slot 3 Netelligent
10/100 TX
Bus 0
5th Slot 4
(new device)
SMART-2/P
Drive Array
Bus 1*
6th
Slot 5
(new device)
Netelligent
Dual
10/100 TX
Bus 2*
7th
Slot 6
SMART-2/SL
Drive Array
Bus 3*
8th
Secondary
Bus (4)
Host to PCI
Bus bridge
Bus 4*
9th Slot 7 Empty N/A
10th Slot 8 SMART-2/SL
Drive Array
Bus 5*
11th Slot 9 Empty N/A
12th Slot 10 Netelligent
Dual
10/100 TX
Bus 6*
13th Slot 11 Empty N/A
As with Test 1, the PCI BIOS assigns 0 to
the Primary Bus and continues
downstream with the controller discovery
process.
The NIC in slot 3 does not contain a PCI
bridge it assumes the bus number of the
bus where it resides, which in this case is
bus 0. It is the first network controller
detected by the PCI BIOS.
A PCI bridged Intelligent drive array
controller was ADDED to the server in slot
4. The PCI BIOS increments the PCI bus
number to 1 and assigns it to the bridge on
the controller.
A PCI bridged NIC was ADDED to the
server in slot 5. The PCI BIOS increments
the PCI bus to 2 and assigns the bus
number to the bridge on the controller. All
bus numbers assigned later in the
discovery from here are affected.
Intelligent drive array controller with a PCI
bridge detected in slot 6. The PCI BIOS
increments the PCI number to bus 3 and
changes the assignment of the bus
number on the array controller.
The PCI BIOS discovers the Secondary
Bus and assigns it bus 4, a changed
number.
Intelligent drive array controller with PCI
bridge detected in slot 8. The PCI BIOS
increments the PCI bus number to 5
changing the bus number assignment on
the array controller.
Slot 9 is empty, no PCI bus number
assignment
NIC in slot 10 contains a PCI bridge and
the PCI BIOS increments the bus number
to 6 changing the bus number assignment.
Slot 11 is empty, no PCI bus number
assignment.
*Bus number is different than previous configuration.