4.15 PCI Bus Number Register
The PCI bus number register is programmed by the host system to indicate the bus number of the PCI bus to which
the PCI6x21/PCI6x11 controller is connected. The PCI6x21/PCI6x11 controller uses this register in conjunction with
the CardBus bus number and subordinate bus number registers to determine when to forward PCI configuration
cycles to its secondary buses.
Bit
7
6
5
4
3
2
1
0
Name
Type
Default
PCI bus number
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
Register:
Offset:
Type:
PCI bus number
18h (Functions 0, 1)
Read/Write
Default:
00h
4.16 CardBus Bus Number Register
The CardBus bus number register is programmed by the host system to indicate the bus number of the CardBus bus
to which the PCI6x21/PCI6x11 controller is connected. The PCI6x21/PCI6x11 controller uses this register in
conjunction with the PCI bus number and subordinate bus number registers to determine when to forward PCI
configuration cycles to its secondary buses. This register is separate for each PCI6x21/PCI6x11 controller function.
Bit
7
6
5
4
3
2
1
0
Name
Type
Default
CardBus bus number
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
Register:
Offset:
Type:
CardBus bus number
19h
Read/Write
00h
Default:
4.17 Subordinate Bus Number Register
The subordinate bus number register is programmed by the host system to indicate the highest numbered bus below
the CardBus bus. The PCI6x21/PCI6x11 controller uses this register in conjunction with the PCI bus number and
CardBus bus number registers to determine when to forward PCI configuration cycles to its secondary buses. This
register is separate for each CardBus controller function.
Bit
7
6
5
4
3
2
1
0
Name
Type
Default
Subordinate bus number
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
Register:
Offset:
Type:
Subordinate bus number
1Ah
Read/Write
00h
Default:
4−10
TI [ TEXAS INSTRUMENTS ]
