PA-RISC Chipsets
HP Itanium zx1 chipset
HP Itanium zx1 is a chipset designed for HP Itanium computers in the early 2000s. It was used by HP also in later 64-bit HP 9000 and Integrity PA-RISC servers, with some adaptations for Itanium and PA-RISC buses. HP zx1 consists of two custom main parts that connect CPUs, memory and I/O to the Itanium system main buses: Pluto and Mercury.
- HP Pluto zx1 memory and I/O controller (MIO) – main chipset controller
- Processor bus
- Two independent memory buses
- I/O channels (I/O ropes)
- HP Mercury zx1 I/O adapters (IOAs) connect PCI-X/AGP slots and I/O devices to Pluto
The rest of the I/O chipset is made up of standard third-party components such as SCSI controllers, Ethernet.
Pluto
Many Itanium and PA-RISC workstations and servers use the HP Pluto memory and I/O controller (MIO) as part of the zx1 chipset. Pluto is based on the Astro IOMMU, extending it for Itanium-2 processors and bus interfaces, DDR memory and faster I/O links.
- Processor bus: Itanium-2 processor bus for up to four CPUs, maximum of 200 MHz bus with 128-bits for up to 6.4 GB/s data rate.
- Two memory buses with peak 8.0 GB/s at maximum clock of 266 MHz DDR.
- I/O system based on eight separate 500 MB/s I/O links for individual PCI, PCI-X or AGP bridges. Peak aggregate I/O bandwidth is 3.2 GB/s
- Support for DDR SDRAMs
- Maximum supported memory of 16 GB to 64 GB with SME memory extender
- 16-entry I/O TLB
- 16-entry coherent I/O cache
Mercury
HP Mercury is a PCI/AGP bridge for PA-RISC and Itanium systems based on an I/O ropes architecture. It is part of the zx1 chipset used on Itanium systems, based on the Elroy PCI bridge, extending it for AGP devices and faster I/O ropes. Most systems use several Mercury chips to attach PCI/AGP buses to the multiple I/O ropes. Each Mercury attaches one PCI or AGP bus to up to four 500 MB/s I/O ropes.
Mercury is often used together with the Pluto I/O and memory controller.
- Attaches to one to four (bundled) I/O ropes
- Provides one PCI, PCI-X or AGP 2.0 bus
- Multiple Mercurys can be used in a single system
- Support for PCI 2.1, also some support for PCI 2.2
- Support for PCI-X
- Support for AGP 1X, 4X and 4X
- PCI data width of 32 or 64 bit
- PCI clock of 33 or 66 MHz
- PCI-X clock of up to 133 MHz
- Up to six PCI slots
- No support for 5 V PCI
Used in
- HP Integrity rp3410, rp3440, rp4410, rp4440, rp7420 servers
- HP Integrity rx1600, rx1620, rx2600, rx2620, rx2660 rx3600, rx5670, rx6600, rx7620, rx7640, rx8620, rx8640 servers
- HP Superdome mainframes
- HP zx2000, zx6000 workstations
Documentation
- zx1 mio (Memory and I/O) External Reference Specification Hewlett-Packard Company (March 2003, Revision 1.0) parisc linux
- HP zx1 ioa ERS External Reference Specification Ropes to AGP/PCI/PCI-X Bridge (.pdf) Hewlett-Packard Company (April 2003, Revision 3.2) parisc linux