The proliferation of FPGAs into the embedded computing industry has opened up many new pathways for designers to design cost-effective systems that will withstand technology upgrades, changes in application requirements, and requests for low volumes for system components. Because it allows a user to update functionality after the device has left the manufacturer, FPGA technology gives embedded designers the flexibility to configure both customized and standard products. They can rethink the way systems are constructed and build ones that significantly advance existing technologies and blaze new paths for cutting-edge embedded systems.
FPGAs are now incorporated into a variety of embedded computing components including 6U CompactPCI (CPCI) single board computers (SBCs), blade servers, and PCI mezzanine cards (PMCs), as well as 3U CPCI products, computer-on-modules (COMs), and their related components.
Where Can FPGA Take You?
In addition to programming flexibility, the downward spiral in costs and exponential increase in capacity and functionality of FPGAs have significantly contributed to their growing use. When compared to application-specific integrated circuit (ASIC) technology, which had been the popular, albeit expensive choice for application-specific customization, FPGAs cost considerably less with more available flexibility in terms of upgrades and programming. Research and development costs for an ASIC can run into six figures, significantly impacting the necessary return on investment of systems, as well as the production and manufacturing cost requirements to bring a component into profitable operating range.
At the heart of FPGA technology are the IP cores, which reduce time to market and costs, two of the biggest issues with which a system designer must contend. IP cores are widely available from several manufacturers and can be developed by the designers as well.
As FPGA technology grows, so does the number and functionality of IP cores. MEN Micro alone has over 40 standard cores designers can access to eliminate time consuming, expensive board redesigns, and there are numerous other cores available from third party vendors. Additional information can be found at www.fpgacentral.com
The cost-effectiveness and widespread availability of FPGA technology has lowered the entry barrier for many companies and industries. This has not only increased the demand for these types of products, but increased the number and types of companies looking to utilize FPGAs in their embedded systems. The cost and programming benefits of FPGA technology are especially advantageous for designers who require only a small number of components, and they are a significantly growing segment of FPGA users.
For example, one of the newest IP cores on the market is an Ethernet core that enables communication between an external physical Ethernet chip and a host application. Some newer embedded applications utilizing this new core include standard net interfaces for embedded CPUs, intelligent Ethernet switches and real-time Ethernet applications like AFDX (in avionics) as well as distributed I/O for industrial applications. Ethernet functionality cost-effectively implemented as an IP core offers the biggest advantage for rugged (high temperature) and long-term availability requirements typically found in transportation and avionics applications.
The Ultimate in System Flexibility
Two recently developed concepts aim to make FPGAs even more attractive to embedded systems designers by capitalizing on their inherent high temperature operation and programming flexibility.
First introduced in January 2007, the Universal Sub Module (USM) concept implements a board's desired functionality through one or more IP cores in an FPGA to easily transform specialized I/O requirements into a series of standard products. Essentially, the different IP cores allow users to change a card's functionality sans hardware modifications to the main module. The USM simply plugs into the respective base mezzanine (PMC, conduction cooled PMC, XMC or M-Module), so functionality can be changed at any time by using different IP cores.
Product development is limited to the USM module and the FPGA content, significantly speeding time to market — a critical factor in system design — and IP cores can be imported into a newer FPGA and tailored to current needs. Because the mezzanine lifecycle no longer depends upon commercially available components, this concept protects against component obsolescence, too, taking systems in a very cost-effective direction.
FPGAs in Harsh Environments
Another significant FPGA-based technological advancement is ESMexpress, currently in the process of ANSI-VITA standardization (ANSI-VITA 59, RSE Rugged System-On-Module Express). First, take the existing COMs model of developing complete computers on a mezzanine board, limiting development of individual functionality to the carrier board (the carrier board also "carries" the FPGA — e.g. an Aria GX connected to the ESMexpress module through PCI Express) and then combine it with a highly rugged design. The result is safe, reliable embedded system operation in harsh, rugged and mobile environments.
A recent VITA Standards Organization (VSO) meeting regarding ESM - express, held in the fall of 2008, yielded some significant advancement of the standard itself, further moving VITA 59 RSE towards complete standardization. Some of the noteworthy advancements are the addition of a display port and HDMI as well as support of a high definition audio low voltage I/O mode that allows carrier boards to support both 3.3 V and 1.5 V. Also, PCIexpress (PCIe) or Serial RapidIO is now allowed on all formerly dedicated PCIe pins. Additional areas being defined include the thermal specification for the modules and thermal guidelines; mechanics compliant to VITA 3.0 in order to use the modules with CPCI and VPX; and the integration of additional interfaces, including USB 3.0 and 10 Gbit Ethernet over CAT6 cables.
ESMexpress provides power dissipation of up to 35 Watts while providing 100% EMC protection by mounting the populated PCB to a frame and completely enclosing the module in an aluminum housing. A mechanically-robust connector specified for MIL and railway applications supports differential signals with up to 8 GHz, features a stacking height of 5 mm with a minimum tolerance of +/-0.3 mm, is equipped with fixed contacts for power supply and is specified for an operating temperature of -55°C to +125°C. And, as with the FPGA-based USM concept, ESMexpress provides exceptional long-term system availability since the IP cores can always be updated to modify or upgrade system functionality.
FPGA technology has laid the groundwork for many different growth areas in embedded computing. Not only have new technologies and standards stemmed from the flexibility and functionality of FPGAs, but more designers now have access to embedded solutions that help to bring system costs down while extending the overall lifecycle of a system through affordable, easy technology upgrades. These types of milestone industry advancements, such as the growing use of FPGA and the related concepts that subsequently develop, are significant achievements for the industry as a whole. Make way for FPGA.
This article was written by Stephen Cunha, Vice President, MEN Micro Inc. (Ambler, PA). For more information, contact Mr. Cunha at