The VXS Ecosystem Continues to Thrive



The VME Switched Serial (VXS) system computing architecture has been released since 2006 and features a vast ecosystem of boards, backplanes, chassis and test products. The wide range of boards includes IO, processors and switches with specialized converter, recorder and data-processing functions. In fact, there are over 80 VXS products in the market and/or deployed from nearly 20 companies.

Backwards Compatibility to VME

VXS offers backwards compatibility to VME-based systems and preserves hardware and software investments in the technology. From three-row 16-bit, 40 Mbytes/sec to 32- bit (3U) and 64-bit (6U) (80 Mbytes/sec) to five-row VME64x (160Mbytes/sec and 320 Mbytes/sec with 2eSST), VME has always had increased performance along with compatibility to previous specifications. VXS also carries on this tradition. The VXS design starts with a standard VME64x backplane design and implements a high-speed fabric by replacing the existing P0 connector with the Multi-Gig 7 Row connector and adding hub slots fully populated with the new connector. However, the backplane is backwards compatible to VME64x/VME, allowing standard VME and VME64x cards (without the P0 connector) to be used in the system. (See Figure 1.)

Figure 1: VXS Switch cards can be routed to the P0 Multi-gig connector across an otherwise typical VME64x slot. VXS provides an easy path of backwards compatibility to VME/VME64x.

Figure 1: VXS Switch cards can be routed to the P0 Multi-gig connector across an otherwise typical VME64x slot. VXS provides an easy path of backwards compatibility to VME/VME64x.

Backwards compatibility is a very important issue. Here are some of the key reasons to maintain it:

  • Preservation of investment in a technology
  • Reuse of existing cards/components with ability to upgrade
  • Working on a proven, tested platform
  • Multiple vendors/choices of legacy platform
  • Less risk of obsolescence as new compatible products are available in the roadmap

Performance

A significant boost in performance is provided by a higher speed Multigig connector in the P0 position and the added switched fabric capability. VME systems with 2eSST have a theoretical performance of 320 Mbps while VXS theoretically can offer up to 36 Gbps aggregate bandwidth. The VXS architecture is expected to be adopted in many SIGINT, radar, sonar and other high data/image processing applications for mil/aero applications. It would also be a solid fit in upgrading VME-based or new applications for medical, communications, laboratory, industrial and other commercial systems.

VITA 41 Specification Updates

The VITA 41 specification for VXS has several sub-specifications or “dot specs.” VITA 41.6 1X Gigabit Ethernet Control Channel has been ratified by ANSI. The control channel is parallel to the data plane defined in 41.0 and operates independently of the data plane. VITA 41.6 is implemented using SGMII, a high speed serial (SERDES) link over a transmit-and-receive pair, where the pins for the control channel are separate from the data plane. The physical link operates at 1.25 gigabits per second. There are up to two 2 links (250 MB/s) per payload card. Another specification, VITA 41.8 10 Gigabit Ethernet Protocol Layer Standard is at ANSI for accreditation. The standard calls out 10 gigabit Ethernet as the primary fabric using four XAUI ports at 3.125 Gbps each. An alternative configuration uses 10GBASE-KX4 which adds auto-negotiation and better channel/backplane definition.


Figure 2: New VXS backplane with Gigabit Ethernet control plane per VITA 41.6 from Elma Bustronic.

Figure 2: New VXS backplane with Gigabit Ethernet control plane per VITA 41.6 from Elma Bustronic.

VXS Ecosystem Continues to Expand

There are also a number of new VXS products coming out. Elma Bustronic recently announced VITA 41.6-compliant backplanes (specification described above) and is also introducing new higher-speed VXS backplanes. (See Figure 2.) It is expected that some VXS backplanes and boards will start to be designed at levels above today’s 3.125 Gbps data rates to 5.0-6.25 Gbps levels.

Tek Microsystems just announced a new VXS signal processor based on the Xilinx Virtex-6 FPGA technology. The board is compatible with legacy VME systems as well as newer ANSI/VITA 41 VXS-based systems in both laboratory and deployed/rugged applications. (See Figure 3.) Pentek also announced a PowerPC- and Virtex-4-based FPGA I/O processor in the VXS architecture. It comes offered in convection- and conduction-cooled formats and with ruggedized options. (See Figure 4.)

With new GigE control options, higher data rate backplanes and boards, and a continuously expanded line of VXS boards, the architecture continues to thrive.

Figure 3: New VXS signal processor from Tek MicroSystems based on Virtex-6.

Figure 3: New VXS signal processor from Tek MicroSystems based on Virtex-6.

Figure 4: New PowerPC and Virtex-4-based VXS IO processor from Pentek.

Figure 4: New PowerPC and Virtex-4-based VXS IO processor from Pentek.

What about VPX?

VPX is becoming a very popular standard in mil/aero applications, particularly since the launch of OpenVPX, which ensures system interoperability for the architecture. VPX uses the same Multigig connector family as VXS, but it does not utilize the VMEbus (except in hybrid designs). The topology for VPX is distributed or centralized, while VXS is standardly centralized (Star or Dual Star configurations). Many mil/aero customers will use VPX with its performance density, IO availability and 3U height option. (VXS is not available in 3U size standard.) However, VXS is an excellent option for applications that do not require VPX’s specific performance benefits. Many designers will find VXS attractive in that it offers high performance, but is typically less complex and more cost-effective than VPX. If VME/VME64x boards are used, VXS has inherent backward compatibility.

VXS VPX
30G+ Performance x x
Full ecosystem x x
Backwards compatibility x w/hybrid only
Use of both PMCs & XMCs x XMC only
Low hardware costs x
Low software upgrade costs x
Simple design, implementation x
Fully defined and mature specification x
More available slots in 19″ chassis (typical) x
100G+ performance x
Amount of user IO x
Standard RTM connector/solution x varies
Slot pitch .8″ payload, 1.0″ switch 1.0″ typical
Base Maximum channels Switch: 192 pairs, Payload: 16 pairs 6U: 192 pairs, 3U: 64 pairs
Sizes 6U 3U, 6U
Voltages 3.3V, +V5, +-V12 5V, 12V, 48V
Topologies (typical) Centralized (Star, Dual Star) Mesh, Centralized, Hybrid

VXS Now and Into the Future

The VXS architecture is a strong fit for many of today’s embedded computing applications. With a wide ecosystem and smooth compatibility with VME/VME64x, it offers many advantages. New VXS products continue to emerge that offer increased performance and design flexibility. For more information on VXS, visit www.vita.com/vxs.html.

Justin-Moll
Justin Moll has 15 years of high-tech marketing and sales experience and has been with Elma Electronic since 2000. As the director of marketing for Elma Bustronic, he has led the company’s charge in several next-generation backplane technologies. Justin is active in VITA and PICMG and has been a guest speaker at several industry events. He has been elected chair of the VXS Marketing Alliance and has served as the VP of marketing for the StarFabric Trade Association.

Contact Information

Elma Electronic Inc.

44350 S. Grimmer Blvd.
Fremont, CA, 94538
United States

tele: 510-565-3400
fax: 510-656-3783
sales@elma.com
www.elma.com

Share and Enjoy:
  • Digg
  • Sphinn
  • del.icio.us
  • Facebook
  • Mixx
  • Google
  • TwitThis

Tags: