RNS-based enhancements for direct digital frequency synthesis
William A. Chren · IEEE Transactions on Circuits and Systems II Analog and Digital Signal Processing · 1995
Two synthesizer designs are presented which exemplify the advantages of the use of the residue number system in direct digital frequency synthesis. The Frequency Agile Direct Synthesizer (FADS) exhibits a frequency switching latency which is reduced by more than a third below that of traditional, binary number system-based designs. The Reduced Area Direct Synthesizer (RADS) has a chip area which is reduced by more than 40% below that of the traditional designs. The area reduction is due to the decomposition of the sine ROM into several small look-up tables accessed in parallel. The latency reduction is due to the shortening of the carry paths in the Phase Accumulator.>