HP Integrity rx7640 and HP 9000 rp7440 Servers User Service Guide

• Management processor (MP) status LED (tri-color)
• Cell 0, 1 status (tri-color) LEDs
Figure 5 Front Panel LEDs and Power Switch
Cell Board
The cell board, illustrated in Figure 6, contains the processors, main memory, and the CC application
specific integrated circuit (ASIC) which interfaces the processors and memory with the I/O, and
to the other cell board in the server. The CC is the heart of the cell board, enabling communication
with the other cell board in the system. It connects to the processor dependent hardware (PDH)
and micro controller hardware. Each cell board holds up to two processor modules and 16 memory
DIMMs. One or two cell boards can be installed in the server. A cell board can be selectively
powered off for adding processors, memory, or for maintenance of the cell board, without affecting
the other cell board in a configured partition.
Figure 6 Cell Board
The server has a 48 V distributed power system and receives the 48 V power from the system
backplane board. The cell board contains DC-to-DC converters to generate the required voltage
rails. The DC-to-DC converters on the cell board do not provide N+1 redundancy.
The cell board contains the following major buses:
• Two front side buses (FSB), each with up to two processors
• Four memory buses (one going to each memory quad)
• Incoming and outgoing I/O bus that goes off board to an SBA chip
Detailed Server Description 15