Cell PA-RISC Chipset
HP Cell was a crossbar chipset used in 64-bit PA-RISC rp servers and HP Superdome mainframes.
The Central Electronics Complex (CEC) interconnects individual system and processor cells
via crossbars.
Several cell boards were seated in the backplane of the systems for cell-to-cell links and I/O functionality.
CC, the Cell Controller, is the central chipset of each cell. CC connects local processors and memory of cells to SBA I/O links and XBC crossbar. XBC is the chip that provides the main backplane function. Different backplanes can be tied together through links in XBCs with high-bandwidth low latency connections.
M2 are HP Cell memory controllers on each cell board. There are eight M2 controllers in two banks on each CC. Requests and addresses are sent directly from CC to memory, with data returning through M2s.
RIO is the master I/O controller in HP Cell, called SBA. Each SBA provides sixteen 12-bit links called ropes to which slave I/O controllers connect, the LBAs. These LBAs are Elroy PCI bridges that convert the links from the SBA into PCI buses.
Core I/O is a card set that provides standard I/O functions and plugs into PCI-64 or special slots to provide third-party I/O functions. Different cards were availaible: MP/SCSI card and LAN/SCSI, for the following devices:
- Two dual-channel Symbios Logic 53C1010 Ultra160 SCSI controllers
- Dual-channel Symbios Logic 53C896 Ultra2-Wide SCSI-3 controller
- Gigabit Ethernet networking
- Console, serial and management controllers
- Fast-Ethernet DEC 21142/43 for Management LAN
- Optional second Core I/O card for redundancy or partitioning
Several buses were used in Cell:
- Runway+ processor bus for up to four processors at 8.0 GB/s.
- Memory bus to M2, for up to two memory
banks
with 4.0 GB/s peak. - The SBA I/O links to the off-cell SBA have 2.0 GB/s peak, the XBC link to the crossbar for cell-to-cell communication 8.0 GB/s peak.
Used in
- N4000 (rp7405, rp7410)
- Superdome
Documentation
- hp server rp7410 whitepaper (URL gone)
- HP nPartition-capable Servers (URL gone)
- User Guide hp rp7405/7410 Servers (URL gone)