HP Integrity rx7640 and HP 9000 rp7440 Servers Installation Guide

• DC-to-DC converters
• Power monitor logic
• Two local bus adapter (LBA) chips that create internal PCI buses for communicating with the
core I/O card
The backplane also contains connectors for attaching the cell boards, the PCI-X backplane, the
core I/O board set, SCSI cables, bulk power, chassis fans, the front panel display, intrusion
switches, and the system scan card. Unlike Superdome or the HP Integrity rx8640, there are no
Crossbar Chips (XBC) on the system backplane. The “crossbar-less” back-to-back CC connection
increases performance.
Only half of the core I/O board set connects to the system backplane. The MP/SCSI boards plug
into the backplane, while the LAN/SCSI boards plug into the PCI-X backplane.
Figure 10 System Backplane Block Diagram
System Bacplane to PCI-X Backplane Connectivity
The PCI-X backplane uses two connectors for the SBA link bus and two connectors for the high
speed data signals and the manageability signals.
SBA link bus signals are routed through the system backplane to the cell controller on each
corresponding cell board.
The high speed data signals are routed from the SBA chips on the PCI-X backplane to the two LBA
PCI bus controllers on the system backplane.
Clocks and Reset
The system backplane contains reset and clock circuitry that propagates through the whole system.
The system backplane central clocks drive all major chip set clocks. The system central clock circuitry
features redundant, hot-swappable oscillators.
I/O Subsystem
The cell board to the PCI-X board path runs from the CC to the SBA, from the SBA to the ropes,
from the ropes to the LBA, and from the LBA to the PCI slots seen in Figure 11 (page 18). The CC
on cell board 0 and cell board 1 communicates through an SBA over the SBA link. The SBA link
consists of both an inbound and an outbound link with an effective bandwidth of approximately
11.5 GB/sec. The SBA converts the SBA link protocol into “ropes.” A rope is defined as a
high-speed, point-to-point data bus. The SBA can support up to 16 of these high-speed bi-directional
Detailed Server Description 17