FOLDED BUTTERFLY MODULE, PIPELINED FFT PROCESSOR USING THE SAME, AND CONTROL METHOD OF THE SAME

摘要

A folded butterfly module performs a radix-22 butterfly operation, and includes: a buffer operable to store first and second to-be-stored data and output first and second stored data; a first multiplexer operable to output one of the second stored data and input data as first selection data; a butterfly operator performing a radix-2 butterfly operation on the first stored data and the first selection data to generate operation data and the second to-be-stored data; a second multiplexer operable to output one of the input data and the operation data as the first to-be-stored data; a third multiplexer operable to output one of the operation data and the second stored data as second selection data; and a multiplier generating output data that equal a product of the second selection data and twiddle data.

主权项

1. A folded butterfly module adapted to perform a radix-22 butterfly operation, said folded butterfly module comprising:
a buffer for receiving first to-be-stored data and second to-be-stored data, and operable to store the first and second to-be-stored data and to output first stored data and second stored data; a first multiplexer coupled to said buffer for receiving the second stored data therefrom, adapted to receive input data, and being operable to output one of the second stored data and the input data as first selection data; a butterfly operator coupled to said buffer and said first multiplexer for receiving the first stored data and the first selection data respectively therefrom, said butterfly operator being operable to perform a radix-2 butterfly operation on the first stored data and the first selection data to generate operation data and the second to-be-stored data; a second multiplexer coupled to said butterfly operator and said buffer, adapted to receive the input data and to receive the operation data from said butterfly operator, and being operable to output one of the input data and the operation data as the first to-be-stored data; a third multiplexer coupled to said butterfly operator and said buffer for receiving the operation data and the second stored data respectively therefrom, and being operable to output one of the operation data and the second stored data as second selection data; and a multiplier coupled to said third multiplexer for receiving the second selection data therefrom, said multiplier being operable to generate output data that equals a product of the second selection data and predetermined twiddle data.