PA-RISC Chipsets
Astro chipset
HP Astro is a chipset for HP 64-bit PA-RISC computers, mostly used in HP Visualize workstations.
It was used in PA-8500, PA-8600
and PA-8700 PA-RISC systems with rope
-based architecture, which used Astro as main system controller and IOMMU with Runway+/Runway DDR buses and I/O devices controlled by HP Elroy PCI bridges.
Astro is the main memory and I/O controller which attaches to Runway:
- Memory attaches to Astro with a peak data rate of about 2.0 GB/s at 125 MHz
- Up to eight I/O links (ropes) with each 250 MB/s attach to Astro.
- Astro supports 120/125 MHz SDRAMs for a maximum supported memory of 40 GB
- 16-entry fully associative I/O TLB
- 16-entry fully associative coherent I/O buffer cache
Astro bus attachments:
- Runway+/Runway DDR is the main processor and memory bus: one to four CPUs attach to Runway with 64-bit, parity-protected.
- HP Elroy I/O adapters attach PCI bridges via the I/O ropes to Astro: One or two ropes per Elroy PCI bridge, then PCI slots or devices attach to Elroy bridges
- PCI buses attach to the multiple Elroy bridges, in 33 or 66 MHz, 32 or 64-bit variants. I/O devices, adapters and slots attach to PCI
- HP Pluto is the successor of Astro for Itanium-2 processors and buses; it works very similar.
Elroy
HP Elroy is a PCI bus bridge that attaches one PCI bus to one or more I/O ropes, used in HP PA-RISC computers. Elroy was often used with the HP Astro memory and I/O controller.
- Peak bandwidth of up to 500 MB/s
- Multiple Elroys can be used in a single system
- Support for Turbo and Twin Turbo slots — attached via one or two links respectively
- Support for PCI 2.1, 1X, 2X and 4X bus
- PCI data width of 32 or 64 bit
- PCI clock of 33 or 66 MHz
Used in
- HP 9000 A400 (rp2400, rp2430), rp2405, A500 (rp2450, rp2470) servers
- HP Visualize B1000, B2000, B2600 workstations
- HP Visualize C3000, C3600, C3650, C3700, C3750 workstations
- HP Visualize J5000, J5600, J6000, J6700, J7000, J7600 workstations
- HP 9000 L1000 (rp5400), L2000 (rp5450), L1500 (rp5430), L3000 (rp5470) servers
- Elroy: HP 9000 N4000 (rp7400), HP 9000 N4000 (rp7405, rp7410) servers
Documentation
- Astro
External Reference Specification Introduction
Astro External Reference Specification Error Handling
Astro External Reference Specification R2I Operations
Astro External Reference Specification Register Map
Astro External Reference Specification Runway Interface
Astro External Reference Specification Memory Map
Hewlett-Packard Company (February 2000, Revision 1.2) parisc linux - Elroy ERS (External Reference Specification) — Ropes to PCI Bridge Chip Hewlett-Packard Company (January 2000, Revision A (1.4) parisc linux