US 7,606,852 B2Granted

CORDIC unit

AssigneeIHP-GmbH-Innovations for High Performance Microelectronics/Institut fur Innovative Mikroelectronik

InventorsKoushik Maharatna, Eckhard Grass, Banerjee Swapna, Dhar Anindya Sundar

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Abstract

A CORDIC unit for the iterative approximation of a vector rotation through a rotary angle θ by a number of elementary rotations through elementary angles αi, including elementary rotation stages for respectively affecting an elementary rotation through an elementary angle αi as an iteration step in the iterative approximation. After such an elementary rotation there remains a residual angle through which rotation is still to be affected. The elementary rotation stages of the CORDIC unit are adapted for rotation through elementary angles αi given by powers of two with a negative integral exponent. The CORDIC unit can also include a triggering device for triggering the elementary rotations, a triggering device which is adapted prior to each iteration step to compare the residual angle to at least one of the elementary angles and to omit those elementary rotation stages whose elementary angles are greater than the residual angle.

Claims9

Dependent claims

A CORDIC unit for effecting a rotation of a vector by a rotary angle, comprising:

a plurality of elementary rotation stages, each for effecting an elementary rotation of a vector through a respective elementary angle αi and
a triggering device operatively engaged with said plurality of elementary rotation stages and configured to iteratively select and trigger a respective one of the elementary rotation stages to effect the respective elementary rotation of the vector, wherein the elementary rotation stages are configured to rotate the vector through elementary angles αi which are given by respective powers of two with a negative integral exponent, and
wherein the triggering device is configured to determine, prior to triggering a respective next elementary rotation during the rotation of the vector, a residual angle that remains between the rotary angle and a sum of all elementary angles, by which the vector has been rotated so far during the rotation of the vector and to refrain from triggering all those of the elementary rotation stages, which are configured to effect the elementary rotation through those of the respective elementary angles, which are greater than the residual angle.

Dependencies are inferred from the claim text.