Electronic Design

EiED Online>> Bus and Board Show: Part 1

This year’s Bus and Board show was held in chilly Long Beach, Calif. The press felt a little bit like frozen fish at the Mercury event on Sunday at the Long Beach Aquarium. Fortunately, only part of it was outside and the aquarium was interesting with a mix of boards and racks in between tanks of sharks and anemones.

Ray Alderman, Executive Director of VITA, (see Fig. 1) kicked off the main event Monday. It’s the 25th year for the VME bus, so this show was a bit more festive then in the past. An improved economy helps too. Military and high-end applications such as medical have done well over the years, but the communications side is finally coming back. This bodes well for technologies like AdvancedTCA and MicroTCA as well as CompactPCI, although Ray has his own views of these.

The Bus and Board show consists of a set of presentations as well as a small trade show (see Fig. 2) that gets rather busy during the breaks. The show tends to target the press and insiders, but the type of technology presented is of more general interest. You can get a look at much of the technology mentioned here at other shows coming up, like the Embedded Systems Conference.

I spent a good deal of time meeting with various companies. I have included this company information as individual articles so you can check out your favorite. As with most shows, I didn’t get to meet with everyone. Likewise, I was able to peruse some of the sessions and presentations, but you can download most of the slide shows from these at the Bus and Board website.

The presentations included an interesting mix, including an application from Mercury Computer that employs IBM’s Cell processor. Moving from applications like the forthcoming Sony Playstation 3 to a ruggedized platform opens some interesting approaches to system design that might be usable in a variety of industrial applications.

RoHS is still on the tip of everyone’s tongue. More on this presentation later. Likewise, fabrics remain at the top of most people’s list, and there was a fabric panel discussion that I will cover later as well. Finally, there were two workshop tracks: RapidIO and VITA. RapidIO’s move from standard to product has finally occurred and it looks like a hot topic for embedded applications. It’s fast and handles short messages very nicely.

Justin Moll from Elma Bustronic gave a presentation on “The Backplane Revolution.” Justin brought up the problems encountered addressing the new high-speed fabrics. He also noted that only 15% to 20% of the backplanes delivered are standard, off-the-shelf products. The rest have some level of customization.

Backplanes are key to the success of fabrics because these kinds of backplanes are hard to design and implement. It’s definitely not something the typical developer will want to tackle. It is hard enough making short runs for PCI Express on an adapter. Imagine hundreds of traces on a single backplane. Crosstalk, jitter, and even stub length affect the overall reliability of the system. If that is not enough, heat dissapation can be a problem as well. And it’s not just a problem for the boards that plug into the backplane.

Check out the links for the companies I was able to interview at the show. Each had one or more technical or product-related announcements. You’ll find a good deal on fabrics, PCI Express, and FPGAs.

Overall, the Bus and Board show was quite interesting this year. There will probably be a good bit of hoopla about the VME anniversary throughout the year, but there should be. No other bus has lasted this long or supports such a wide range of applications. It is still going strong even with the merging of meshes (actually fabulous fabrics), so don’t expect it to go away for at least another 25 years.

Now for a few of the details.

RoHS (Restriction of Hazardous Substances)
If you don’t know about RoHS by now then you better get your act together because it affects everyone. Kevin Rankin made a presentation on the topic bringing up a range of issues that everyone will have to address. Check out Electronic Design’s RoHS page (www.elecdesign.com/rohs/) for more details.

Kevin discussed issues such as tin whiskers and even brought up the issue of patents. The change to new solders means there will be many different metal combinations that will be tried. Alloys and solder processes can be patented, so be prepared.

I heard of a number of potential problems that I was not initially aware of. For example, tin whiskers are more of a problem now because voltages are lower, whereas the whiskers often acted like a fuse in the past and eliminated the problem. Of course, that could be a problem as well. Likewise, the finer trace and pin spacing means whiskers do not have to grow as much to cause a problem. There is even an issue if a whisker does vaporize as it forms a plasma. If it sticks around long enough it can cause a short and plasmas can handle hundreds of amps. Definitely nasty stuff.

Kevin’s presentation is on the Bus and Board website.

Fabrics Panel Discussion
Fabrics is a hot topic even though most applications can still be handled by parallel bus implementations such as PCI and VME64. A rather friendly panel (see Fig. 3) took questions from the audience. The panel included:

  • Infiniband: Thad Omura, Mellanox Technologies
  • Rapid I/O: Tom Cox, RapidIO Trade Association
  • HyperTransport: Peter Robinson, AMD
  • Ethernet: Clayton Tucker, Motorola ECC
  • PCI-Express: Larry Chisvin, PLX Technology
  • ASI: Rajeev Kumar, Intel
  • Aurora: Bill Smith, QinetiQ
  • Each panelist had ten minutes to show the latest and greatest about their topic area. Of course, each presented their technology in the best light, ranging from Thad Omura highlighting the 3rd-generation InfiniBand to Bill Smith touting the point-to-point Aurora technology.

    You are probably familiar with all but Aurora unless you have been using Xilinx FPGAs. Aurora is a high-speed serial point-to-point connection system. It uses the same kind of connections as the other high-speed serial fabrics like InfiniBand and Serial RapidIO, but it does not move through a switch or employ a higher level protocol. It just shovels data around. It’s best suited for applications that need to connect a board that sources data to another board that processes/consumes it. VMetro is one company that is using Aurora. Check out my coverage of VMetro for more details.

    Audience questions were the usual mix, such as asking for clarification of a particular protocol and its use or asking if TCP/IP is the best way to handle embedded data flow. What was clear from the Q&A was that these technologies are going to coexist and many are complementary. For example, PCI Express is often the glue that will hold together a system that might employ 10-Gig Ethernet or InfiniBand.

    RapidIO Workshop
    Serial RapidIO’s rise was apparent at the RapidIO workshop. Presentations included the use of RapidIO in storage, communication, video, and wireless applications. No, the latter was not wireless RapidIO but rather using RapidIO to implement the infrastructure for wireless access points.

    The term Serial RapidIO is also waning, with RapidIO alone being the replacement. This is a good thing and I need to get used to it. It is no longer necessary to differentiate the serial version from Parallel RapidIO that was the first implementation of RapidIO. Parallel RapidIO implementations were few and targeted a small set of developers. All the new work is with Serial RapidIO. Also, the Serial RapidIO architecture matches that used by other fabrics like InfiniBand and ASI where multiple serial links can be logically bound together.

    Presentations included some of the best reasons for looking at RapidIO (yes, the serial kind). Texas Instruments highlighted their 6482 DSP that includes a RapidIO link. PowerPC chips from AMCC also include these kinds of links, allowing systems to be built exclusively with processor and DSP chips linked by the fabric. PCI Express need only apply to external peripherals connected to the processor chips.

    It is clear that RapidIO has a large vendor pool and that it’s advancing on all fronts.

    VITA Standards Workshop
    Bus and Board would not be a show without boards based on VITA standards. This workshop was primarily an overview of the latest standards that essentially address new products that were presented at the show. The standards covered included VITA 41 (VXS), VITA 42 (XMC), VITA 46 (VPX), and VITA 48 (VPX-REDI) in addition to the VITA 49 digital IF standard and the VITA 50 module-cooling standard. If that is not enough, consider the following:

  • VITA 51, Reliability Prediction
  • VITA 52, Lead Free
  • VITA 53, Market Surveillance
  • VITA 54, ePMA
  • VITA 55, Virtual Streaming Protocol
  • VITA 56, EMC
  • VITA 57, FPGA I/O Mezzanine
  • One of the big differences from last year is the emphasis on abbreviations instead of standard VITA numbers. VXS, XMC, and VPX are the names in the game now. It is also clear that all will coexist but it is not clear when or how any will emerge as the long-term volume leader. Everyone has their own view.

    VXS maintains VME64 compatibility while adding switch fabric support. It uses a 5-row DIN connector plus a multi-gigabit differential connector for fabrics. InfiniBand and (serial) RapidIO are already standards. Early this year, the Gigabit Ethernet and PCI Express proposals will move to standards.

    XMC is the mezzanine card standard for high-speed serial/fabric communication. It adds one or two 114-pin connectors for serial communication with up to four PMC connectors. The standard should handle communication speeds up to 10 Gbits/s. That is well above the average 2.5 Gbits/s used by existing standard fabrics, including parallel and serial RapidIO, PCI Express, HyperTransport, and Aurora. The XMC recommendation is in trial use at this point.

    And there is the VITA 46 VPX and VITA 48 VPX REDI (Ruggedized Enhanced Design Implementation) standard. It is an interesting play on names and there was a bit of juggling coming up with the REDI name. Bottom line, it sounds good and is easy to remember. Regardless, it is something designers can start working with now.

    VPX employs just the serial fabric interface, foregoing the VME bus found in the VXS standard. VPX uses the same 3U and 6U form factor, but the tie to VME is through VXS. The VPX REDI standard includes cooling technology specification such as conduction, convection, and liquid cooling. VPX REDI is designed to handle harsh environments like aircraft and military vehicles while providing a better upgrade and repair model that is conducive to a 2- instead of 3-layer maintenance process.

    The presentations on the Bus and Board website will provide you with a more detailed explanation of these standards.

    For more information about the Bus and Board show, see the following:

    AcQ InduCom Does Data Acquisition

    ACT/Technico Sports CompactPCI and PMC Disk Storage

    AiTech Targets Military And Space Systems

    AMD Brings 64 Bits To The Embedded Space

    Bittware Does DSPs

    Curtiss-Wright Ready With VPX

    Elma Delivers A Full Mesh Backplane and VXS Extender

    Mercury Pushes Cell and VXS

    Performance Technologies Packs Storage and Opteron Into CompactPCI

    SBE Pushes IP Storage and VoIP

    Related Links
    Applied Micro Circuits Corp.


    Bus and Board Show

    Hypertransport Consortium


    InfiniBand Trade Association

    PCI Industrial Computer Manufacturers Group


    RapidIO Trade Association

    Texas Instruments


    Xilinx (Aurora protocol)

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