How FFT accelerator (FFTA) on ADSP-SC58x/ADSP-2158x is different as compared to ADSP-214xx processors / What are the major features of FFTA on ADSP-SC58x/ADSP-2158x ?

FFT Accelerator on ADSP-SC58x/ADSP-2158x is a completely new design as compared to the FFT accelerator on ADSP-214xx processors. The major differences/features of the FFT accelerator on ADSPSC58x/ADSP-2158x are:

• Unlike in ADSP-214xx, the FFTA on ADSP-SC58x/ADSP-2158x, supports pipelined FFT operations which means that it can process multiple channels in such a way that all the units input DMA, compute engine, and output DMA can run in parallel on different channels.

• Supports both complex and real FFT and IFFT operations.

• Supports 64 to 2048 points in small FFT mode and 4096 to 4 M points in large FFT mode.

• Supports the IEEE-754/854 single-precision floating-point data format, round to even Radix-4 butterfly efficiency at a radix-2 (integer power of two) point granularity

• Automatic insertion of zeros for real FFTs

• Supports automatic conjugating of the twiddle factors for IFFT

• Supports automatic scaling of FFT and IFFT inputs.

• Hardware support for windowing

• Hardware support for magnitude squared FFT output

• Hardware support for pipelined data flow

• Dedicated high speed DMA engines for data load and dump with a data width 64-bit clocked by SYSCLK supports data and coefficient access from both on-chip (L1/L2) and off-chip memories (L3)

• Optional support for bypassing the compute engine to perform high speed memory to memory MDMA transfers

• Compute engine clock division options for power reductions, supports 1:1, 1:2, 1:4 and 1:8 clock ratio modes