Intel SE7501WV2 User Manual

host bridge PCI interface (ICH) arbitration lines REQx* and GNTx* are special cases in that they 
are internal to the host bridge.

The following table defines the arbitration connections. 

P32_REQ4*/P32_GNT1* 

Promise ATA-100 Controller ( ATA Version Only) 

P32_REQ0*/P32_GNT0* 

ATA Rage XL video controller 

 

There are two peer 64-bit, 100-MHz PCI-X bus segments directed through the P64H2 I/O 
Bridge. 

The first PCI-X segment, P64-B, provides a single I/O Riser slot capable of supporting full 
length, full height PCI cards. The PCI cards must meet the PCI specification for height, inclusive 
of cable connections and memory.  In addition to the riser connector, the P64-B segment also 
has an Intel

®

 82546EB dual channel Gigabit Ethernet controller. 

The second PCI-X segment, P64-C, provides a second I/O riser slot.  Because of physical 
limitations of the baseboard, this riser slot is only capable of supporting low-profile PCI cards. In 
addition to the riser connector, the P64-C segment also has an Adaptec* 7902 dual channel U-
320 SCSI controller. 

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 tables show the bit to 
which each IDSEL signal is attached for P64-B and P64-C devices, and corresponding device 
description. 

23 

On-board Gigabit Ethernet controller 

24 

First slot of the riser card 

25 

Second slot of the riser card ( for a 3-slot riser card) 

26 

Third slot of the riser card (for a 3-slot riser card)