Intel IQ31244 user manual PCI-X Interface, Primary PCI Bus

Intel® IQ31244 Customer Reference Board

2.0PCI-X Interface

The IQ31244 contains two 64-bit PCI-X buses. The primary PCI bus, clocked at up to 100 MHz, interfaces with the Intel® 80321 I/O Processor, the Intel® 82546 Dual-Port Gigabit Ethernet Controller, the Intel® 31154 133 MHz PCI Bridge, and the PCI-X expansion slot.

Note: The PCI-X expansion slot must be used for PCI-X cards only.

The secondary PCI bus, clocked at 100 MHz, provides the interface between the Intel® 31154 133 MHz PCI Bridge and the four Intel® 31244 PCI-X to Serial ATA Controllers.

In addition, the two buses can communicate with each other by means of the Intel® FW31154

133 MHz PCI-X Bridge. The primary bus and secondary bus can operate at different speeds and modes independently of each other. Depending on the peripheral add-in card capability, the primary bus can operate at either conventional PCI, PCI-X 66 MHz, or PCI-X 100 MHz. The mode of the IQ31244 primary bus can also be set by jumpers Z3 and Z4, as shown in Table 6.

Table 6.	Primary PCI Bus
	Type of PCI	Speed	Z4	Z3
	PCI-X 100	100 MHz	Open	Open
	PCI-X 66	66 MHz	Open	Closed
	Conventional PCI	66 MHz	Closed	Open

14 User’s Manual