Abstract: Complex approximate functions are often used in traditional sine amplitude compression approach for ROM compression in direct digital frequency synthesizer to achieve high compression rate. This paper proposes a new hierachical linear interpolation approach for ROM compression and phase-to-sine amplitude conversion of sinusoid output DDS. Experimental results show that the proposed approach can achieve a higher compression rate with equal spectral performances and simpler hardware structure than most of the previous works.

Key words: direct digital frequency synthesis, compression ratio, interpolation function, storage compression