The FFT butterfly operation in 4 processor cycles on a 24 bit fixed-point DSP with a pipelined multiplier

Most of the existing Digital Signal Processors (DSPs) are optimized for a fast and efficient computation of the Fast Fourier Transform (FFT). However, there are only two floating-point DSPs available, which perform the butterfly operation of a FFT in 4 processor cycles, but no fixed-point DSP is designed that way. The new 24 bit fixed-point DSP DAISY, which is able to execute the butterfly in 4 cycles even using a two-stage pipelined multiplier, is described in this paper. With this pipelined multiplication it is possible to reduce the processor cycle time significantly.