Standard for a Versatile Backplane Bus: VMEbus
|Publication Date:||12 March 1987|
This IEEE 1014 standard specifies a high-performance backplane bus for use in microcomputer systems that employ single or multiple microprocessors. It is based on the VMEbus specification, released by the VME Manufacturers' Group in August of 1982. The bus includes four subbuses: data transfer bus, priority interrupt bus, arbitration bus, and utility bus. The data transfer bus supports 8-, 16-, and 32-bit transfers over a non-multiplexed 32-bit data and address highway. The transfer protocols are asynchronous and fully handshaken. The priority interrupt bus provides real-time interrupt services to the system. The allocation of bus mastership is performed by the arbitration bus, which allows to implement round robin and prioritized arbitration algorithms. The utility bus provides the system with power-up and power-down synchronization. The mechanical specifications of boards, backplanes, subracks, and enclosures are based on IEC 297 specification, also known as the Euroboard form factor.