Military Embedded Systems

Managing obsolescence with PMC, XMC, and FMC mezzanine solutions


September 10, 2013

RJ McLaren


PMC, XMC, and FMC transition custom legacy system designs effectively and enable IP reusability for OEMs.

Managing obsolescence has long been a challenge for military designers. It can be a complex process to define long-term road maps for systems that might have originally been developed as full-custom solutions while at the same time managing costs and time to deployment, and continually increasing system performance in field deployments. These primary drivers for military designers and OEMs call for sophisticated product life-cycle planning to preserve the integrity of deployed systems, while establishing a tangible path forward that addresses changes that might be either anticipated or unexpected.

Preparation and predictability ensure the consistency and longevity of deployed solutions. When engineers of custom designs in particular struggle with these factors, other design considerations must come into play. The result is often a blend of traditional obsolescence mitigation efforts, such as extended commitment to availability of certain components, and evolution to standards-based options as a means of ensuring long-term system viability and performance. Mezzanine cards in three widely available standards – PCI Mezzanine Card (PMC) IEEE P1386.1, Switched Mezzanine Card (XMC) VITA 42, and FPGA Mezzanine Card (FMC) VITA 57 – are showing promise in managing obsolescence, effectively evolving custom solutions to a range of standards-based platforms.

Diverse mezzanines enable evolution

Mezzanines offer flexible and modular I/O options that can take the place of custom I/Os in an obsolescence management plan. PMC, XMC, and FMC (see sidebar on FMC) are the commercial form factors that dominate the market as standards-based components; as a result, carrier boards can readily accept mezzanines from a broad range of vendors and suppliers in a well-defined product ecosystem. Further, PMC, XMC, and FMC each support the primary mil/aero platforms (for example, VME, VPX, and CompactPCI) and are compatible with both 3U and 6U architectures.

This option functions in sharp contrast to previously customized designs where OEMs developed their own specialized I/Os and put them directly on a proprietary card design. When the chips or other components in these systems faced End-of-Life (EOL), manufacturers typically had to weigh the options of respinning the board with a new chipset versus executing an extended buy of components to manage the system into a longer product life cycle. Further, once an extended buy was committed, future changes might still warrant the need for additional product life-cycle management efforts. XMC, PMC, and FMC mezzanine solutions are proving valuable in delivering a standards-based alternative for transitioning such custom systems to standards-based solutions with well-defined and cost-efficient product road maps.

Packaging specialized I/O into modular mezzanine solutions serves to repurpose IP and define a significantly larger user base for what once were costly, fully custom designs. This not only answers the established COTS mandates, but increases competitive viability for OEMs seeking a broader range of military contracts.

By coupling mezzanine modules with carrier boards in platforms ranging from VME to CompactPCI to VPX, designers are poised to either jump their systems to small footprint blackbox solutions or more traditional 3U or 6U systems in the same platform.

Mezzanines as rugged building blocks

Within the standard platforms such as CompactPCI, VME, and VPX, carrier cards are consistently designed and available in the same 3U and 6U form factors. Each has a defined interconnect that plugs into the backplane, as well as a mezzanine connector and pinout that readily support the PMC mezzanine form factor. PMCs can be purchased in volume, and can be designed to function alongside the processor card or to exist on a separate carrier card – ultimately enabling reusability of the mezzanine on multiple bus architectures.

This concept can be illustrated by a traditional 6U VME deployment transitioning first to the use of a mezzanine card solution (PMC, XMC, or FMC) as a drop-in replacement to reduce program risk. The Kontron VM6250 makes available 2x PMC or XMC slots or an FMC slot for such cases (Figure 1).


Figure 1: A traditional 6U VME deployment transitioning first to the use of a mezzanine card solution (PMC, XMC, or FMC) as a drop-in replacement to reduce program risk

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This solution can deliver upgrade performance for a defined period of time and allow OEMs to effectively control planned performance steps within a system’s deployment. The mezzanine solution can maintain system performance and minimize downtime, while giving system engineers time and pre-validated options for integration into a next-generation solution as the next step in its life cycle.

Most next-generation, high-speed, standards-based boards and systems will accept the same mezzanines, allowing OEMs to reuse them in many different applications by repackaging to meet the program’s exact requirements. 3U/6U systems use backplanes to interconnect the processor, switch, and I/O (using mezzanines) specific boards.

Sidebar 1

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Mezzanines enable evolution

Strenuous performance demands continue to translate to design challenges for military OEMs. As DoD budgets focus on both efficiency and performance, managing obsolescence is essential in meeting expectations. As system deployments extend years beyond original expectations, migrating custom designs to standards-based solutions is an increasingly important factor in managing obsolescence. Mezzanine options have proven their viability as flexible, modular, and cost-effective design choices for these programs (Table 1).


Table 1: As system deployments extend years beyond original expectations, FMC, PMC, and XMC mazzanines have proven their viability when migrating custom designs to standards-based systems.

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The mezzanine module has a long history and its implementation is a popular approach to reusing proven technology in many different systems. The PMC may be the longest existing standard discussed here and is well-proven within the industry, but it is limited to compatibility with legacy parallel bus architectures. The XMC standard is the next evolution to this robust mezzanine offering many options. XMC integrates seamlessly with VPX high-speed interconnects and will continue to grow in popularity as more vendors and products are added to the market. The latest mezzanine form factor, the FMC, offers the greatest flexibility and configuration options, but is more complicated because of FPGA core development. Its use will continue to grow, but will most likely be as a more customized path that can be tailored to customer application requirements.

These mezzanines give system engineers a product-rich ecosystem that will provide the best solution to managing their products’ obsolescence life cycles along with laying the foundation for future product expansion and flexibility for application requirements.

RJ McLaren is the Portfolio Manager for Military and Commercial Aerospace Products at Kontron America. He is responsible for product and business development for rugged systems along with Kontron’s industry standard COMe, AMC, CompactPCI, VME, and VPX product lines in North America. Contact him at [email protected]

Kontron America 858-677-0877


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