Intel® Server Board SE7505VB2
PCI I/O Subsystem
5. PCI I/O Subsystem
5.1 PCI
Subsystem
The primary I/O bus for the server board SE7505VB2 is PCI, with three independent PCI bus
segments. The PCI buses comply with the PCI Local Bus Specification, Rev 2.3. The P32-A bus
segment is directed through the ICH4 while the two 64-bit segments, P64-B and P64-C, are
directed through the P64H2 I/O Bridge. The table below lists the characteristics of the three PCI
bus segments.
Table 7. PCI Bus Segment Characteristics
PCI Bus Segment
Voltage
Width
Speed
Type
PCI I/O Card Slots
P32-A
5 V
32-bits
33 MHz
PCI
Two slots, support full-length cards
P64-B
3.3 V
64-bits
100 MHz
PCI-X
Two slots, support full-length cards
P64-C
3.3 V
64-bits
66 MHz
PCI
One slot, supports full-length cards
5.1.1
P32-A: 32-bit/33-MHz PCI Subsystem
All 32-bit/33-MHz PCI I/O for the board is directed through the ICH4. The 32-bit/33-MHz PCI
segment created by the ICH4 is known as the P32-A segment. The P32-A segment supports
the following embedded devices and connectors:
Serial ATA controller: Silicon Image* 3112A.
One 10/100 Network Interface Controller: Intel 82550PM Fast Ethernet Controller.
2D/3D Graphics Accelerator: ATI Rage XL Video Controller
The Serial ATA controller and the NIC will each be allocated a GPIO to disable the device
.
The
video controller will be disabled when an off-board video device is detected in either the AGP or
PCI bus segments
5.1.1.1
Device IDs (IDSEL)
Each device under the PCI hub bridge has its IDSEL signal connected to one bit of AD[31:16],
which acts as a chip select on the PCI bus segment in configuration cycles. This determines a
unique PCI device ID value for use in configuration cycles. The following table shows the bit to
which each IDSEL signal is attached for P32-A devices and the corresponding device
description.
Table 8. P32-A Configuration IDs
IDSEL Value
Device
16
PCI 33MHz Slot 1
17
PCI 33MHz Slot 2
18
ATI Rage XL Video Controller
19
Intel
82550PM Fast Ethernet Controller (NIC1)
20
SATA controller Silicon Image 3112A
Revision 1.2
Intel part number C32194-002
33
