VMEbus interface with 2eSST capability

Edited by the Electronicstalk editorial team Dec 16, 2002

Thales Computers has released a white paper describing the implementation of its VMEbus interface with 2eSST capability.

Thales Computers has completed testing the 2eSST (Two-edge Source Synchronous Transfer) protocol on its V4G4c high-end computing node and has released a white paper describing the implementation of its VMEbus interface with 2eSST capability.

The VITA 1.5, 2eSST protocol was adopted as a draft standard in 1999 by the VME International Trade Association (VITA).

The new white paper, written by Serge Tissot, Product Development Manager, Thales Computers, describes the features provided by the ALMA2e bridge, including 2eSST transfers at up to 320Mbyte/s, and broadcast to multiple VME slaves using the 2eSST protocol.

The white paper addresses in detail the operation of the ALMA2e in 2eSST mode, including descriptions of extended address modifier (AM) codes for the four available address/data modes, as well as the data source timing for six available data transfer rates ranging from 146 to 320Mbyte/s.

Illustrations are provided from validation studies of the ALMA2e, including read timing, write timing, and setup and hold time.

Use of the 2eSST protocol is expected to help provide a significant boost to the VME embedded computer market, by enabling vendors to provide transfer speeds of 320Mbyte/s while retaining backward compatibility to existing and legacy VMEbus systems.

According to recent projections by members of VITA, the availability of 2eSST may increase the size of the overall VME market by over $300 million by 2005.

The new white paper from Thales Computers discusses a subsequent ASIC design and lists the backward compatible VME64 features of the ALMA2e, retained from the predecessor ALMA64 VMEbus bridge.

These features enable system integrators to incorporate the ALMA2e immediately on existing VMEbus systems while retaining complete VME64 functionality.

The ALMA2e is currently offered on the Thales Computers VxG4c series of high-end 6U VME computing nodes featuring dual or quad Motorola MPC7410 PowerPC processors.

The V4G4c single-slot solution with four 500MHz G4/AltiVec processors is the first in a series of boards offering the ALMA2e.

The white paper is available from the Thales Computers website.