Patent ID: 8788558
Filing Date: 2014-07-22
Classification: G06F

Abstract:
1. A method of operating a data-processing unit to produce a transform expressible through a butterfly diagram, the method comprising: reading a first input data value from a first location of a first buffer, the first location being determined by a first read address based on a first read index; reading a second input data value from a second location of the first buffer, the second location being determined by a second read address based on a second read index; calculating first and second output data values from a first butterfly calculation based on at least the first and second input data values, each of the first and second output data values having a word length W; writing the first and second output data values to a second buffer, wherein the second buffer includes a single-port memory, a memory cell of the second buffer includes two adjacent memory locations and is twice as wide as the word length W, the second buffer includes a selector configured to select one of the two adjacent memory locations of the memory cell, the first and second output data values are concatenated, and the concatenated data values are written as a value having a word length 2 W to adjacent memory locations of the second buffer during a single write cycle, and the adjacent memory locations are determined by a first write address; reading a third input data value from a first location of the second buffer, the first location being determined by a third read address based on the first read index; and reading a fourth input data value from a second location of the second buffer, the second location being determined by a fourth address based on the second read index; the third read address is determined by swapping at least two bits of the first read index, and the fourth read address is determined by swapping at least two bits of the second read index.