VMEbus - technical definition

(VersaModule Eurocard BUS) An expansion bus technology developed by Motorola, Signetics, Mostek and Thompson CSF in the early 1980s. It is defined by the ANSI/IEEE 1014-1987 standard. Supporting up to 21 cards in a single backplane, VMEbus is widely used in industrial, telecommunications and military applications with products available from several hundred manufacturers worldwide. VMEbus cards (VME cards) come in 3U, 6U and 9U Eurocard formats (see Eurocard).

In 1995, VME64 was introduced, which increased the data and addressing paths from 32 to 64 bits and added several enhancements. However, VME boards can be VME64 compliant and provide less than 64 bits of data transfer and/or addressing. In 1997, VME64x (VME64 eXtensions) added features such as new pin connections, support for 3.3 volts and hot swap capability. See VXI, VITA and PMC.