307013-003 Datasheet, PDF (279/848 Pages) Intel Corporation – Intel I/O Controller Hub 7

Chipset Configuration Registers
7.1.35
RPFN—Root Port Function Number for PCI Express Root
Ports (Desktop and Mobile only)
Offset Address: 0238–023Bh
Default Value: 00543210h
Attribute:
Size:
R/WO, RO
32-bit
For the PCI Express root ports, the assignment of a function number to a root port is
not fixed. BIOS may re-assign the function numbers on a port by port basis. This
capability will allow BIOS to disable/hide any root port and have still have functions 0
thru N-1 where N is the total number of enabled root ports.
Port numbers will remain fixed to a physical root port.
The existing root port Function Disable registers operate on physical ports (not
functions).
Port Configuration (1x4, 4x1, etc.) is not affected by the logical function number
assignment and is associated with physical ports.
Bit
31:23
22:20
19
18:16
15
14:12
11
10:8
7
6:4
3
2:0
Description
Reserved
Root Port 6 Function Number (RP6FN) — R/WO. These bits set the function
number for PCI Express Root Port 6. This root port function number must be a
unique value from the other root port function numbers.
Reserved
Root Port 5 Function Number (RP5FN) — R/WO. These bits set the function
number for PCI Express Root Port 5. This root port function number must be a
unique value from the other root port function numbers.
Reserved
Root Port 4 Function Number (RP4FN) — R/WO. These bits set the function
number for PCI Express Root Port 4. This root port function number must be a
unique value from the other root port function numbers.
Reserved
Root Port 3 Function Number (RP3FN) — R/WO. These bits set the function
number for PCI Express Root Port 3. This root port function number must be a
unique value from the other root port function numbers.
Reserved
Root Port 2 Function Number (RP2FN) — R/WO. These bits set the function
number for PCI Express Root Port 2. This root port function number must be a
unique value from the other root port function numbers.
Reserved
Root Port 1 Function Number (RP1FN) — R/WO. These bits set the function
number for PCI Express Root Port 1. This root port function number must be a
unique value from the other root port function numbers.
Intel ^® ICH7 Family Datasheet
279