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 |
| | | | | |
