ROM size reduction with low processing cost for direct digital frequency synthesis

Abstract

A novel sine amplitude compression technique is presented for application in low-power direct digital frequency synthesizers. It is based on a systematic approach aimed at exploiting as much redundancy as possible between the value of a phase angle and its sine amplitude. It is shown that a compression ratio of approximately 19.3 is attained, saving four bits of storage per word. The new technique compares favorably with previous designs in that better storage reduction is accomplished at low processing cost. The technique can be used in conjunction with traditional approaches for even greater area and power reduction. A new direct digital frequency synthesizer architecture based on the technique is presented.