Inventors:
Ning Chen - Austin TX,
Jayakrishnan C. Mundarath - Austin TX,
Pornchai Pawawongsak - Austin TX,
Assignee:
Freescale Semiconductor, Inc. - Austin TX
International Classification:
G06F 15/00
US Classification:
708405, 708400, 708403, 708404
Abstract:
In a data processing system, having a twiddle factor unit, a method for performing a mixed-radix discrete Fourier transform (DFT) having a block size, N, and a maximum block size, Nmax, wherein the maximum block size includes a radix that is not a power of 2 is provided. The method includes receiving a delta value at an input of the twiddle factor unit, the delta value representing a ratio of a modified maximum bock size to the block size, wherein the modified maximum block size is a power of 2. The method further includes using the delta value to obtain a step size for generating indices of a look-up table stored within the twiddle factor unit, wherein the look-up table stores real and imaginary components of twiddle factors corresponding to a set of block sizes of the DFT.