I/O Subsystem; Figure 1-11 System Backplane Block Diagram - HP Integrity rx7640 Installation Manual

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 1-11 System Backplane Block Diagram
MP Core I/O
MP/SCSI
MP Core I/O
MP/SCSI
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 1-12. 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 rope links for a total aggregate bandwidth of approximately 11.5 GB/sec.
Chapter 1
HP Integrity rx7640 Server and HP 9000 rp7440 Server Overview
System backplane
Bulk power supply
Detailed Server Description
PCI-X backplane
Cell board 1
Cell board 0
Cell boards are perpendicular
to the system backplane.
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