Re-configurable FPGAs Replace Legacy 6U VME Boards

Many defense contractors currently find themselves in a quandary regarding support of older systems with custom-designed 6U VME boards. These legacy systems are frequently a victim of component obsolescence problems, yet the military mandates the continuation of their operation. Acromag FPGA modules provide a solution.

FPGAs rise to solve obsolescence issues
Since their invention, FPGAs have rapidly expanded their capabilities. Evidence of these advances are apparent in the core programmable logic which has exploded from dozens to millions of gates plus the addition of complex arithmetic, memory, clocking; and processing functions. The I/O interface has grown from a few I/O lines to more than a thousand and now supports numerous single-ended and differential standards with on-chip terminations and data rates in the gigabit-per-second range. The combination of rich feature sets with device re-programmability makes FPGAs highly adaptive to design changes both during and after initial system development. As a result, FPGA-based solutions are very attractive for a myriad of applications. These reasons have fueled the escalating acceptance of FPGAs as central components in embedded board product designs.

A variety of performance levels
Acromag offers a variety of PMC modules with a range of reconfigurable Xilinx FPGAs. This wide selection allows both the system integrator and the end-user to pick a model with the most appropriate FPGA device for their application requirements. The range of Acromag's FPGA module product lines provide different performance, power consumption, logic capacities, signal interfaces, memory configurations, and data rates. Each new generation of FPGA devices delivers faster speeds, increased logic element density, additional microprocessor capabilities, and more flexible interfaces. Currently, Acromag's sells PMC modules employing an assortment of Virtex-II, Virtex-4; and just recentlyVirtex-5 FPGAs from Xilinx.

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Upgrading radar and satellite systems
Modern replacement systems for radar and satellite applications often implement Acromag's PMC-SX35 module with front-end I/O via plug-in AXM I/O modules. The SX35 version of Xilinx's Virtex-4 FPGA is optimized for DSP tasks and provides sufficient logic resources. The logic core is arranged in "slices" consisting of look-up-tables (LUTs), 18x18 multiplier blocks, and an adder/subtracter with carry functions. Memory is also very flexible with distributed memory deployed for LUTs, FIFOs, and RAM. Blocks of 18Kb RAM can be used for deep FIFOs or larger single/dual-port RAM.

Using Acromag PMC-SX35 FPGA modules and AXM extension I/O, system developers are able to successfully transfer DSP functions into the FPGA thus offloading an intensive computation task from the system's central processor. And most importantly, defense contractors can quickly replace a number of obsolete legacy 6U VME boards with standard COTS PMC modules that are more efficient and enable a more tightly-coupled system.

Capable, affordable, and sustainable
FPGAs are best suited for applications requiring high data rates, parallelism, processing densities, and I/O flexibility. In the end, major issues such as I/O and host interfaces, interprocessor communication, memory configuration, control; and an FPGA framework must all be carefully planned along with unifying software that makes it all accessible to the user. The final result is a modern, cost-effective, embedded computing system that is upgradeable and provides for long term support.