CompactPCI and AdvancedTCA Systems - OpenSystems Media

SPECIALHIGH-END EMBEDDED COMPUTINGplatform size is driving developers to dramaticallyreduce the cost of the payloads.What’s needed are attributable platformpayloadsolutions that still exhibit appropriatelevels of reliability to match theforecasted life expectancies of the platform.A first-order approximation of systemflyaway costs is $10,000 per pound. Thisfigure was developed many years ago on amultispectral Electronic Warfare (EW) systemdevelopment involving six major EWcompanies and has survived many technologyshifts. Technology has provided morecapabilities per pound, but this approximationhas still proven to be adequate forrapidly approximating system costs.System requirementsThe first basic requirement is that the signalprocessing systems must be physicallysmall enough to fit into the new platforms.For many platforms, the commonly used6U VME systems are just too big; 1U, 2U,or 3U form factor solutions are needed.In addition, the signal processing systemsmust adhere to industry standards forboard design and interfaces, if systemsdesigners are to benefit from CommercialOff-the-Shelf (COTS) solutions.Squeezing the processing power of 6Uboards into smaller form factors demandsthe creative use of a specialized adjunctprocessor. Adjunct processors are devicessuch as Field Programmable Gate Arrays(FPGAs) and ASICs, dedicated to a specificcomputationally intensive operation.Because adjunct processors execute asingle task, they can do it with extraordinaryspeed and efficiency. Developerscan partition signal processing operationsamong different types of processors formaximum efficiency, getting more donein less space while accepting the tradeoffof somewhat greater system complexity.True multisensor flexibility demands thesignal processing engine have a varietyof I/O options, all with high-bandwidthinterconnects to the processors. Ideally,these I/O options connect directly to theprocessing boards, as well as supportingsome form of an industry-standard mezzaninecard.operate in harsh environments, they mustbe able to withstand shock, vibration, andtemperature extremes.Processing density and efficiencyOne approach for achieving processingdensity and efficiency for signal processingis to leverage adjunct processingengines such as FPGAs as programmableprocessors. For some front-end signal andimage processing functions, FPGAs havedemonstrated a 10- to 20-fold performanceboost over a PowerPC G4 processor.However, some front-end tasks, suchas filter weight computation and mostback-end processing, still perform muchbetter on a PowerPC processor. In fittingthe most processing power in the smallestspace for a given application, the trickis finding not only the optimum balancebetween FPGAs and PowerPCs, but alsodetermining exactly which model of eachchip to choose.Application software can be partitionedso that certain algorithms go onto theFPGA. FPGA-appropriate algorithmsinclude fixed-point computations or non-Since engineers develop functional softwareaccording to an overall project schedule,they need access to adequate developmenttools, including algorithm libraries andI/O device drivers. If adjunct processorsare employed, efficient development toolsmust support them. And lastly, becausethese systems are often called upon toRSC# 27 @www.compactpci-systems.com/rscCompactPCI and AdvancedTCA Systems / June 2005 / 27