Field-programmable gate array (FPGA) technology has proven to be invaluable to embedded designers for many years. Often acting as an all-in-one solution, FPGAs negate the need for ASIC [application-specific integrated circuit] technology and reduce the cost of custom IP algorithms in silicon. FPGAs have even aided in derisking designs by allowing engineers to modify their logic after silicon is on the board. This approach allows for more efficient prototyping and a faster time to market.

Due to such diverse flexibility, the demands of end users for a specific configuration or interface layout could drag on indefinitely. This presents an additional challenge for commercial off-the-shelf (COTS) manufacturers to design a standard product that will please most users.

Why FMC and how it has sustained since its inception

If FPGA technology was to be a viable product for a mass market, the need to offer many different configurations on a common platform had to be addressed. Thus, a modular approach and defining standards were needed. VITA saw an opportunity to drive such a standard, and FMC was born with VITA 57.1.

Although the FMC standard has now been in existence for about 10 years, it continues to sustain extensive use by a wide variety of COTS manufacturers and FPGA developers such as Xilinx and Altera. Thanks to features such as its small form factor and user-defined pins on the connector, FMC provides features to the end user while ensuring reliable I/O signal integrity at speeds up to 14 gigabits per second (Gb/sec).

FMC to FMC+: What has FMC enabled for system developers?

FMCs are an I/O mezzanine module in a small, standardized form factor that allows for greater design flexibility in many applications. Moreover, FMCs are host carrier-independent, supporting everything from motherboards and 3U/6U VME to VPX and CompactPCI carrier cards, which means that it’s versatile to deploy in development and finished products.

These features are reflected in the upcoming VITA 57.4 FMC+ Standard, as well, where the number of multigigabit interfaces increases from 10 to 24.

In addition, there is an optional extension connector (the High Serial Pin Connector extension, or HSPCe) to boost pin count by 80 positions, arranged in a 4-by-20 array. This configuration brings the maximum multigigabit interfaces to 32 full-duplex channels. Additionally, throughput per multigigabit interface has increased to 28 Gb/sec in each direction.

By adding these high-speed serial lanes, FMC+ will enable designers to use the highest-performance serial devices from suppliers such as Texas Instruments and Analog Devices.

Just as FMC has become widely adopted due to its small form factor and design flexibility, FMC+ is due to follow suit: As most FMC applications are predominantly ADC/DAC and memory-based, FMC+’s serial connectivity is well-positioned to further these objectives. The VITA 57.4 Standard extends support from 10 gigabit transceivers (GTs) to 32 GTs, when using the optional expansion connector. This setup will allow for higher data rates and expanded bandwidth, all of which will fit within the same form factor as FMC.

FMC: Application overview across different industries

Being a connector company, Samtec is positioned to observe FMC and FMC+’s applications across various industries. Since we have begun involvement in these standards, we have seen FMC technologies continue to thrive along with the emergence of FMC+ (Figure 1).

Figure 1: FMC+ mezzanine from Samtec. Photo courtesy of Samtec.

VITA 57.1 is continuing to garner interest from all fields of embedded hardware, from developers designing custom carrier-mezzanine architectures to deployments in space stations. Other applications we have seen include COTS manufacturers employing FMC in rugged designs, as well as FPGAs being used in machine vision standards such as GigE.

As an enabling technology of next-generation rapid prototyping and deployment, FMC is likely to see continued growth well into the future. FPGA technologies, especially with the coming addition of FMC+, should see adoption in software-defined radio, optics, and advanced sensor/radar applications.

Each of these applications shares common requirements, such as more bandwidth, more channels, and the need for a more complete solution. FMC+ should excel in these areas as systems developers can take advantage of its speed and cost-effective approach.

Dylan Lang is Standards Development Manager at Samtec, Inc. and is the Chairman, ANSI/VITA 57 FMC Community.

Samtec www.samtec.com