AXPvme Single-Board Computer

This document provides a technical description of the AXPvme single-board computer, a 6U-sized Versa Module Eurocard (VMEbus) device. It features a low-cost Alpha (DECchip 21066A) processor, integrating memory, I/O bus controllers, and various peripherals on a single module.

Key components and features include:

• Processor: DECchip 21066A, a 64-bit RISC processor with on-chip instruction and data caches, memory and I/O bus controllers, and floating-point support.
• Memory Subsystem: Supports 8 to 128 MB of DRAM main memory with 8-bit ECC for error correction, and a 256 KB or 512 KB external write-back backup cache.
• I/O Subsystem: Based on a 32-bit PCI bus, serving as the main I/O backbone. It includes a VME interface, SIO interface, Ethernet interface, and SCSI interface.
• VME Interface: A full master/slave interface conforming to IEC 821, IEEE1014-1987 standards, supporting A16, A24, A32 address spaces and D08, D16, D32, D64 data transfers. It can operate as a VME system controller and offers programmable scatter/gather (S/G) mapping and byte swapping.
• Peripherals: Includes a PCI-based network interface (Ethernet AUI), a PCI-based SCSI-2 interface, 1-4 MB of flash ROM for console code and diagnostics, a serial line DUART for console, a programmable watchdog timer, three 16-bit interval timers, a battery-backed Time-Of-Year (TOY) clock, and 32 KB of nonvolatile RAM (NVRAM).
• User Interface & Configuration: Features an alphanumeric front panel display for status, a PCI mezzanine connector for optional daughtercards, and four DIP switches to enable/disable various functions like TOY standby power and Flash ROM updates.
• Console: Provides a U*X-like command-line interface for system control, bootstrapping, diagnostics, and debugging, supporting features like pipes, I/O redirection, and scripting.
• Diagnostics: Incorporates ROM-based power-up self-tests (SROM POST) and console-based diagnostic tests for various hardware components, including memory, interfaces, and registers.

The AXPvme is designed for VME real-time and embedded systems where high performance with Digital supported operating systems (OSF/1 and VxWorks) is required.