Multi-granularity parallel FFT computation device

A multi-granularity parallel FFT computation device comprising:

• a first memory and a second memory configured to store butterfly group data;
• a third memory configured to store twiddle factors corresponding to the butterfly group data;
• a first selector;
• a butterfly computation device has input terminals connected to output terminals of the third memory and the first selector, and is configured to perform computation of a butterfly group based on the butterfly group data outputted from the first selector and the corresponding twiddle factors outputted from the third memory, and write a computation result back to the first or second memory;
• a state control unit configured to generate read/write(R/W) addresses and R/W control signals for the first, second and third memories based on current computation node and stage;
• a data reversing network configured to reversely arrange data within a butterfly group;
• the first selector configured to receive initial input data and bit-reversed data from the data reversing network at two input terminals, respectively, and select the bit-reversed data if the current computation node is computation node 0, otherwise select the initial data.