Title :
Redundant Cordic rotator based on parallel prediction
Author :
Antelo, Elisardo ; Bruguera, Javier D. ; Villalba, Julio ; Zapata, Emilio L.
Author_Institution :
Dept. of Electron. y Computacion, Santiago de Compostela Univ., Spain
Abstract :
We present a Cordic rotator, using carry-save arithmetic, based on the prediction of all the coefficients into which the rotation angle is decomposed. The prediction algorithm is based on the use of radix-2 microrotations with multiple shifts in the first iterations and the use of a redundant radix-2 and radix-4 representation for the coefficients in the rest of the microrotations. The use of multiple shifts facilitates the prediction of the coefficients in the case of microrotations where i⩽n/4, being n the precision of the algorithm, and the use of radix-4 microrotations helps to reduce the total number of iterations. The prediction is carried out using the redundant representation of the z coordinate, without any need for conversions to a non-redundant representation. Finally, we present a VLSI architecture based on this algorithm. As the production of the coefficients is very fast, and they are known before starting each microrotation, the resulting architecture can be highly pipelined and consequently appropriate for applications where high speeds are required
Keywords :
digital arithmetic; iterative methods; parallel algorithms; signal processing; carry-save arithmetic; microrotations; parallel prediction; radix-2 microrotations; redundant Cordic rotator; rotation angle; Arithmetic; Contracts; Digital filters; Image processing; Iterative algorithms; Performance evaluation; Prediction algorithms; Production; Signal processing; Zinc;
Conference_Titel :
Computer Arithmetic, 1995., Proceedings of the 12th Symposium on
Conference_Location :
Bath
Print_ISBN :
0-8186-7089-4
DOI :
10.1109/ARITH.1995.465362