A VersaModule Eurocard (VME) bus is a 32-bit computer bus developed by Motorola, Signetics, Mostek and Thompson CSF and includes VME adapters, VME controllers, VME extenders, VME interfaces, VME processors and VME switches. It is defined by the IEEE (Institute of Electrical and Electronics Engineers) standard 1014-1987.
VME buses have many uses including traffic control, weapons control, telecommunication switching, data acquisition, video imaging and robotics. They can withstand shock, vibration and extended temperatures better than the buses used in desktop computers, making them ideal for harsh environments.
Based on the VME IEEE standards set forth in 1987, a VME bus system includes:
1. VME bus mechanical specifications such as board
dimensions, connector specifications and enclosure
2. VME bus electronic specifications for sub-bus structures, signal
functions, timing, signal voltage levels and master/slave
A VME bus interface system has four sub-buses:
1. The arbitration VME bus controls requests from various
devices using an arbiter module, giving permission to each
device to use the bus and notifying requesting devices when
the bus is busy.
2. The data transfer VME bus is used for reading and writing
operations between modules.
3. The priority interrupt VME bus handles interrupts and monitors
the interrupt request lines.
4. The utility VME bus supports a system clock.
VME bus interfaces come in three sizes:
1. VME bus size 3U, which is 4 x 6 inches
2. VME bus size 6U, which is 6 x 12 inches
3. VME bus size 9U, which is 14 x 18 inches
Where to locate more information about VersaModule Eurocard busVME bus information is available in detail at many websites.
Find information on VME bus manufacturersThere are more than 300 VME bus manufacturers worldwide. Some of the larger companies are listed below.
Find information on organizations and associations associated with the VME busTo find out about VME bus usage, try these organizations, which provide a forum for VME bus manufacturers and VME bus users.
VME International Physics Association is another association that monitors the use of VME busses, making sure they are in accordance with IEEE standards.
Locate vendors to buy a VME bus board and VME bus componentsYou can purchase VME interface systems and VME controllers from many different vendors.
- When replacing a VME bus or any VME interface parts, make sure you really need to replace them. When in doubt , check with vendors, manufacturers or other technical sources.
- VME bus interfaces are heavily regulated by the government based on IEEE regulations and standards. Check these standards for proper VME bus usages.