HP Integrity rx8640 and HP 9000 rp8440 Servers Installation Guide
Figure 9 System Backplane Block Diagram
PCI-X Backplane
Cell 0
Cell 1
System Backplane
Cell boards are perpendicular
to the system backplane.
XBC XBC
LBA
LBA
Cell 3
Cell 2
Core I/O 0
Core I/O 1
The two LBA PCI bus controllers on the system backplane create the PCI bus for the core I/O cards.
You must shut down the partition for the core I/O card before removing the card.
Having the SCSI connectors on the system backplane allows replacement of the core I/O card
without having to remove cables in the process.
System Backplane to Cell Board Connectivity
The system backplane provides four sets of connectors, one set for each cell board.
The system backplane routes the signals from the cell boards to the communication crossbars. Cell
boards 0 and 1 are directly connected to the I/O backplane found in the server. Cell boards 2
and 3 can be connected to a separate I/O expansion chassis connected to the system backplane.
System Backplane to Core I/O Card Connectivity
The core I/O cards connect at the rear of the system backplane through two connectors. SCSI and
LAN on a core I/O are accessed via a PCI-X 66 MHz bus. Two LBA bus controllers located on the
system backplane allow communication to the I/O devices. The LBAs are connected to the SBA
on the PCI-X backplane by single ropes.
The system backplane routes the signals to the various components in the system. The core I/O
signals include the SCSI bus for the system hard drives and the bus for the removable media
devices. Each core I/O card provides SCSI buses for the mass storage devices.
The management processor for the chassis resides on the core I/O card, so the system backplane
also provides interfaces required for management of the system. These interfaces and the
manageability circuitry run on standby power.
You can remove the core I/O cards from the system as long as you shut down the partition for the
core I/O card before removing the card. The hot-plug circuitry that enables this feature is located
on the system backplane near the core I/O sockets.
Detailed Server Description 17