While the “V” in “VME” actually stands for “Versa” (as in “Versa Module Eurocard”), it could arguably also stand – especially in the defense and aerospace commercial off-the-shelf (COTS) market – for “venerable.” For the decades prior to the advent of the VPX architecture in 2006, VME was unquestionably a de facto board standard for rugged open architecture systems. Today, there are thousands of VME boards installed in the field and untold millions of dollars invested in hardware and systems software currently used on those deployed systems.
That’s why the 2014 announcement that the popular Tempe TSI148 VMEbus bridge chip was being declared end of- life (EOL) by its supplier made major news in the industry. Predictably, many COTS board vendors announced the EOL of some VME boards, and vendors responded with a range of proposed strategies and workarounds to the bad news, including board last-time buys. The good news is that the “V” in VME can now also stand for “vitality” thanks to the emergence of field-programmable gate array (FPGA)-based VME interface solutions that provide a powerful one-two punch to simultaneously address the industry’s continuing need for a VME bus interface chip, while at the same time ending the anxiety that another EOL – lurking off in the future – might again raise the specter of obsolescence for these critical devices.
By implementing a VME interface in an FPGA device, it is now possible to develop new VME boards that are 100 percent form-/fit-/function-compatible with earlier VME interface designs. Even better, because the FPGA IP for the VME interface core is managed by the board vendor, the future threat of obsolescence is eliminated. That’s because the same VME interface code can be later moved into newer FPGA devices to maintain long-term availability. This approach enables system designers to replace their older Tempe-based VME modules with new boards that maintain the same VME interface capability, but are updated with an FPGA VME interface solution to provide plug-and-play technology refresh options for legacy systems.
New VME module designs, built with an FPGA-based interface, will provide a much-needed technology roadmap for system designers who aren’t yet ready to make the move to VPX or don’t need to because of lower-level performance requirements. One advantage of the FPGA approach is that the VME interface can be implemented in a device that requires less power than the older IDT Tempe device, an attractive improvement for size, weight, and power (SWaP)-sensitive COTS systems. Another important result stemming from the adoption of new FPGA-based VME interfaces is the strong message sent to the customer base that COTS vendors are truly committed to ongoing support for VME, both for existing fielded designs and for new designs to come.
One example of the FPGA-based VME board design is the recently announced SVME/DMV-196 single-board computer which is powered by NXP’s QorIQ Power Architecture (PA) T2080 processor. Designed for technology insertions, this VME board is fully pin- and feature compatible with previous generations of Curtiss-Wright’s VME SBCs. It promises performance increases of two to six times in a similar power envelope and at a lower price point compared to earlier single- and dual-processor PA VME SBC designs. An additional step to help mitigate obsolescence is the T2080 processor’s 15-year life cycle supported by NXP.
By integrating a VME interface into reconfigurable FPGAs, COTS vendors can now keep their VME legacy systems updated with the latest processor technologies for many years. For those customers who are locked into existing VME boards that use the existing IDT Tempe chip and do not have the ability to perform a technology insertion, some vendors have secured large quantities of the EOL device and can offer longevity of supply and longevity of repair plans to ensure that a customer’s existing Tempe-based boards will continue to be manufacturable for many more years.
FPGAs are helping to keep VME alive. Long live VME!
One example of an FPGA-based VME interface alternative is Curtiss-Wright’s Helix, a field-tested and proven PCI Express-to-VME64x transparent bridge that provides a full VME64xMaster/Slave interface with a direct bridge to a PCI Express upstream port
Graham Pitcher of New Electronics Magazine speaks to Aaron Frank and Andrew McCoubrey of Curtiss-Wright about the future of VME.
Senior Product Manager
Aaron Frank joined Curtiss-Wright in January 2010. As a Senior Product Manager within the C5ISR group, he is responsible for a wide range of COTS products utilizing advanced processing, video graphics/GPU and network switching technologies in many industry-standard module formats (VME, VPX, etc.). His focus includes product development and marketing strategies, technology roadmaps, and being a subject matter expert to the sales team and with customers. Aaron has a Bachelor of Science in Electrical Engineering degree from the University of Waterloo.
Helix - The New VMEbus Interface
This video features Curtiss-Wright's Helix FPGA solution which provides the same functionality as the discontinued Tsi148 VME Interface Chip.
The VME bus form factor has been an extremely powerful building block for the defense industry since its inception in 1981. The industry has deployed tens of thousands of VME systems, with a significant number of these systems still in active use.