Abstract: A digital array signal processor and an associated method are described for implementing the fast Fourier transform radix-4 butterfly algorithm. The digital array signal processor is an integrated circuit with a four stage pipeline and can perform a radix-4 butterfly operation on four complex operands every 80 nanoseconds. Using the decimation-in-frequency implementation of the radix-4 butterfly algorithm, the digital array signal processor includes a first stage for distribution of complex input operand values, a second stage for performing addition and subtraction operations, a third stage for performing multiplication operations and a fourth stage for distribution of the output operand values. The digital array signal processor can be reconfigured to perform a radix-2 butterfly operation on two sets of two complex numbers during the 80 nanosecond machine cycle as well as frequently used arithmetic and logic operations.