Long-term Open System Architecture Still Viable for Military Systems
ANSI/VITA 1 is the original VMEbus specification for 8-, 16-, 32, and 64-bit parallel-bus computer architectures that can implement single and multiprocessor systems. The mechanical specifications of boards, backplanes, subracks, and enclosures are based on IEC 297 and IEEE 1101.1 specifications, also known as the Eurocard form factor. ANSI/VITA 1.1 now supports a 160 pin connector, a P0 connector, geographical addressing, voltages pins for 3.3V, a test and maintenance bus, and EMI, ESD, and front panel keying per IEEE 1101.10.
ANSI/VITA 1.5, 2eSST is an extension of the ANSI/VITA 1-1994, VME64 and ANSI/VITA 1.1-1997, VME64x standards. It defines a new transfer protocol, based upon source synchronous concepts, that permits the VMEbus to operate at rates up to 320MB/s. As technology improves, this rate can be extended to higher levels.
ANSI/VITA 31.1, Gigabit Ethernet on VME64x, defines a pin assignment and interconnection methodology for implementing a 10/100/1000BASE-T Ethernet switched network on a VME64x backplane via a P0 connector. This is the first generation of serial switched fabric solutions implemented in VMEbus backplanes. ANSI/VITA 31.1 on P0, as well as several other serial schemes, all work with the VME32, VME64 and VME2eSST configurations.
XMC (VITA 42) defines an open standard for supporting high-speed, switched interconnect protocols on the popular PMC form factor. It adds connectors for the high-speed interconnects while retaining the main features of the PMC specification, staying within the height. It provides better definition for carrier cards, and allows for optional configuration without PMC connectors using only the high-speed connectors.