FAST FOURIER TRANSFORM CO-PROCESSOR (FFTC) - TOWARDS EMBEDDED GFLOPS

摘要

Many signal processing applications and algorithmsperform their operations on the data in the transformdomain to gain efficiency. The Fourier Transform Co-Processor has been developed with the aim to offloadGeneral Purpose Processors from performing thesetransformations and therefore to boast the overallperformance of a processing module. The IP of thecommercial PowerFFT processor has been selected andadapted to meet the constraints of the spaceenvironment.In frame of the ESA activity “Fast Fourier TransformDSP Co-processor (FFTC)” (ESTEC/Contract No.15314/07/NL/LvH/ma) the objectives were thefollowing:Production of prototypes of a space qualified version ofthe commercial PowerFFT chip called FFTC based onthe PowerFFT IP.The development of a stand-alone FFTC AcceleratorBoard (FTAB) based on the FFTC including theController FPGA and SpaceWire Interfaces to verify theFFTC function and performance.The FFTC chip performs its calculations with floatingpoint precision. Stand alone it is capable computingFFTs of up to 1K complex samples in length in only10μsec. This corresponds to an equivalent processingperformance of 4.7 GFlops. In this mode the maximumsustained data throughput reaches 6.4Gbit/s. Whenconnected to up to 4 EDAC protected SDRAM memorybanks the FFTC can perform long FFTs with up to 1Mcomplex samples in length or multidimensional FFTbasedprocessing tasks.A Controller FPGA on the FTAB takes care of theSDRAM addressing. The instructions commanded viathe Controller FPGA are used to set up the data flowand generate the memory addresses.The presentation will give and overview on the project,including the results of the validation of the FFTC ASICprototypes.