IDT 89HPES64H16G2 User Manual page 215

IDT PCI to PCI Bridge and Proprietary Port Specific Registers
PBUSN - Primary Bus Number Register (0x018)
Bit
Field
7:0
SBUSN - Secondary Bus Number Register (0x019)
Bit
Field
7:0
SUBUSN - Subordinate Bus Number Register (0x01A)
Bit
Field
7:0
SLTIMER - Secondary Latency Timer Register (0x01B)
Bit
Field
7:0
IOBASE - I/O Base Register (0x01C)
Bit
Field
0
3:1
7:4
PES64H16G2 User Manual
Field Default
Type
Name Value
PBUSN RW 0x0
Field Default
Type
Name Value
SBUSN RW 0x0
Field Default
Type
Name Value
SUBUSN RW 0x0
Field Default
Type
Name Value
SLTIMER RO 0x0
Field Default
Type
Name Value
IOCAP RWL 0x1
Reserved RO 0x0
IOBASE RW 0xF
Description
Primary Bus Number. This field is used to record the bus number
of the PCI bus segment to which the primary interface of the bridge
is connected.
This field has no functional effect within the switch but is imple-
mented as a read/write register for software compatibility.
Description
Secondary Bus Number. This field is used to record the bus num-
ber of the PCI bus segment to which the secondary interface of the
bridge is connected.
Description
Subordinate Bus Number. The Subordinate Bus Number register
is used to record the bus number of the highest numbered PCI bus
segment which is behind (or subordinate to) the bridge.
Description
Secondary Latency Timer. Not applicable.
Description
I/O Capability. Indicates if the bridge supports 16-bit or 32-bit I/O
addressing.
0x0 - (io16) 16-bit I/O addressing.
0x1 - (io32) 32-bit I/O addressing.
Reserved field.
I/O Base. The IOBASE and IOLIMIT registers are used to control
the forwarding of I/O transactions between the primary and sec-
ondary interfaces of the bridge. This field contains A[15:12] of the
lowest I/O address aligned on a 4KB boundary that is below the
primary interface of the bridge.
16 - 5 April 5, 2013