comment on this article

The need for speed

From Raceway to a switched serial fabric. By Graham Pitcher.

There's nothing wrong with the VME backplane as such. However, if you're looking to send high speed data between a number of boards in a card cage, then you are likely to run into problems. The reason – apart from it being a 30year old concept – is that VME is a bus based system. And that, despite several upgrades to the specification, has limited the amount of data that can be transferred.

Despite VME's bus structure, it retains widespread support because of its inherent mechanical and electrical stability. Legacy is the watchword when developing enhancements for VME systems.

Over the years, a number of attempts have been made to unblock the data transfer bottleneck whilst retaining support for the basic VME architecture. One of these attempts is Raceway, first developed by Mercury Computer Systems in 1994.

Raceway, in its first instantiation, was a high speed synchronous backplace fabric capable of delivering 32bit data between VME boards at rates of up to 160Mbyte/s. What was important about the development was the fact that this high speed data transfer was independent of the VME bus. So users, in theory, had the best of both worlds: the VME architecture and higher speed data transfer.

Rodger Hosking, vice president of board manufacturer Pentek, expanded: "The idea of Raceway was to allow a flexible backplane fabric to connect boards in a VME environment such that each board in the cage could talk to any other through a crossbar switch, which would be configured by the message itself. At the same time, you could have simultaneous traffic between other pairs of boards in the system. It was fundamentally different to a bus architecture, where only one pair of boards at a time could use the bus."

Click here to request this article by email

Author
Graham Pitcher

Comment on this article


This material is protected by MA Business copyright See Terms and Conditions. One-off usage is permitted but bulk copying is not. For multiple copies contact the sales team.

What you think about this article:


Add your comments

Name
 
Email
 
Comments
 

Your comments/feedback may be edited prior to publishing. Not all entries will be published.
Please view our Terms and Conditions before leaving a comment.

Related Articles

LTE IoT 8 Click board

MikroElektronika (MIKROE) has launched LTE IOT 8 Click – a new member of its ...

To gel or pad?

New electronic product generations bring new challenges associated with thermal ...

Extreme boards!

“Extraordinary circumstances often bring along with them extraordinary ...

Custom MMIC design

Plextek RFI CEO Liam Devlin discusses the technical and commercial ...

Between the layers

ZofzPCB is a free 3D Gerber viewer that allows designers to see inside the ...

Cloud Solver

Today, new technologies enter the market very, very quickly. For some of the ...

A digital revolution

The micro:bit Educational Foundation has been launched as a not-for-profit ...