Filter
Top Products
4−10
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 PCI7x21/PCI7x11 controller is connected. The PCI7x21/PCI7x11 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 PCI bus number
Type RW RW RW RW RW RW RW RW
Default 0 0 0 0 0 0 0 0
Register: PCI bus number
Offset: 18h (Functions 0, 1)
Type: 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 PCI7x21/PCI7x11 controller is connected. The PCI7x21/PCI7x11 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 PCI7x21/PCI7x11 controller function.
Bit 7 6 5 4 3 2 1 0
Name CardBus bus number
Type RW RW RW RW RW RW RW RW
Default 0 0 0 0 0 0 0 0
Register: CardBus bus number
Offset: 19h
Type: Read/Write
Default: 00h
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 PCI7x21/PCI7x11 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 Subordinate bus number
Type RW RW RW RW RW RW RW RW
Default 0 0 0 0 0 0 0 0
Register: Subordinate bus number
Offset: 1Ah
Type: Read/Write
Default: 00h