Area and latency improvements for direct digital synthesis using the residue number system

Two residue number system-based direct digital synthesizers are presented. The High-Agility Direct Synthesizer exhibits a frequency switching latency which is reduced by as much as 50% below that of traditional, binary number system-based designs. The Reduced Area Direct Synthesizer has a chip area which is reduced by more than 40%. The area reduction is due primarily to the decomposition of the sine ROM into several small look-up tables, while the latency reduction is due to the shortening of the carry paths in the phase accumulator