Area/Delay Efficient Recoding Methods for Parallel CORDIC Rotations

In this paper, an area/delay efficient recoding method for parallel CORDIC (coordinate rotation digital computer) rotation algorithm is proposed. This recoding method can reduce the number of micro-rotation stages when the bit-width of input angle increases. The most critical path of the conventional CORDIC rotation lies in the determination of rotation directions, which depends on the sign of the remaining angle after each iteration. Our proposed method can also predict the rotation direction directly from the binary value of the initial input angle. Our proposed architectures have a more regular and simpler prediction scheme compared to previous approaches using non-parallel CORDIC rotation methods. The critical path delay of our proposed method is reduced compared with parallel CORDIC rotation method