IEC 60822:1988

Overview

IEC 60822:1988 is an international standard defining the Parallel Sub-system Bus (VSB) for the IEC 821 VMEbus architecture. Developed by ISO and the International Electrotechnical Commission (IEC), this standard addresses the integration and coordination needs of high-performance 32-bit microprocessor-based multiprocessor systems. The VSB serves as a local subsystem extension, optimizing data throughput and system performance by enabling efficient communication between processor boards, memory, and I/O components over a high-speed asynchronous bus.

The standard establishes the necessary framework and protocols for subsystem design, supporting both single and multiprocessor configurations. It outlines functional, electrical, mechanical, and protocol specifications for seamless and reliable operation within VMEbus-based environments.

Key Topics

IEC 60822:1988 covers critical aspects of VSB implementation and operation, including:

• System Architecture

  • Defines the role of the VSB as a local extension bus within the broader VMEbus ecosystem.
  • Supports both master and slave modules for flexible subsystem design.

• Bus Operation and Protocols

  • Four cycle types: address-only, single-transfer, block-transfer, and interrupt-acknowledge.
  • Mechanisms for dynamic bus sizing, resource locking, and data caching.
  • Protocols for master/slave interactions and data transfer processes.

• Arbitration Mechanisms

  • Specifies arbitration bus functionality and lines for coordinating access to the data transfer bus.
  • Two arbitration methods: serial (daisy-chained) and parallel (distributed), supporting scalable system architectures.

• Physical and Electrical Specifications

  • Details about VSB board requirements, including power distribution and connector characteristics.
  • Mechanical compatibility with VMEbus systems is stipulated.
  • Electrical requirements for reliable signal integrity, bus driving, and signal line termination.

• Backplane Specifications

  • Requirements for the VSB backplane’s physical and electrical properties, including characteristic impedance and slot assignments for geographical addressing.

• Standard Terminology & Symbol Reference

  • References to IEC standards for terminology (IEC 60050), graphical symbols (IEC 60417; IEC 60617), and letter symbols (IEC 60027).

Applications

The IEC 60822:1988 standard finds practical application in a range of multiprocessor and embedded systems, where high throughput and flexible architecture are critical:

• Embedded Industrial Automation
  Used to build complex automation controllers requiring high-speed local data transfers between processors, memory, and I/O modules.

• Scientific Computing Systems
  Supports fast data movement and efficient resource sharing in laboratory instrumentation, data acquisition, and real-time analysis systems.

• Telecommunications Equipment
  Enables scalable, high-bandwidth backplane connections in telecom switches, routers, and signal processing units.

• Defense and Aerospace
  Ideal for mission-critical multiprocessor embedded systems demanding reliable, robust, and modular communication architectures.

• VMEbus Expansion
  Provides a framework for extending the functionality of existing VMEbus-based platforms with local, high-speed bus connectivity and additional subsystem options.

Related Standards

Implementation and use of IEC 60822:1988 may reference or require compatibility with the following related standards:

• IEC 821: Microprocessor system bus (VMEbus) - Foundation for IEC 822 VSB.
• IEC 60050: International Electrotechnical Vocabulary (IEV) - Standardized terms.
• IEC 60027: Letter symbols to be used in electrical technology.
• IEC 60417 & IEC 60617: Graphical symbols for use on equipment and diagrams.
• IEC 603-2: Connectors for frequencies below 3 MHz with printed boards.

By following IEC 60822:1988, engineers and system architects can ensure interoperability, performance, and modularity in VMEbus-based multiprocessor systems and sub-system implementations.