HP Server rp7420 HP 9000 rp7420 Server - User Service Guide, Fifth Edition - Page 22
Cell Board, buses include two Front Side Buses FBS0 and FBS1, a Memory MID bus, a Crossbar XB bus
View all HP Server rp7420 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 22 highlights
Cell Board The cell board contains several hardware blocks connected by several data buses. The major hardware blocks are the Central Processor Units (CPUs), the Cell Controller, the Memory Controllers, and the Memory. Minor hardware blocks include Clock Distribution, Power Distribution, Reset Circuit, and Platform Dependent Hardware (PDH) Riser Board Interface. The buses include two Front Side Buses (FBS0 and FBS1), a Memory (MID) bus, a Crossbar (XB) bus, and an I/O bus. All these blocks come together at the CC chip. Figure 1-6 Cell Board The HP 9000 rp7420 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. Because of space limitations on the cell board, the PDH/PDHC circuitry resides on a riser board that plugs into the cell board at a right angle. The cell board also includes clock circuits, test circuits, and de-coupling capacitors. Figure 1-7 shows a simplified view of the memory subsystem. It consists of two independent access paths, each path having its own address bus, control bus, data bus, and DIMMs . In practice, the CC runs the two paths 180 degrees out of phase with respect to each other to facilitate pipelining in the CC. Address and control signals are fanned out through register ports to the synchronous dynamic random access memory (SDRAM) on the DIMMs. 22 Overview