Numerically Controlled Oscillators (NCO), also called Direct Digital Synthesizers (DDS), offer several advantages over other types of oscillators in terms of accuracy, stability and reliability. NCOs provide a flexible architecture that enables easy programmability such as on-the-fly frequency/phase. NCOs are used in many communications systems including digital up/down converters used in 3G wireless and software radio systems, digital PLLs, radar systems, drivers for optical or acoustic transmissions, and multilevel FSK/PSK modulators/demodulators.
Lattice provides a parameterizable NCO IP core that supports multiple channels and a Quadrature Amplitude Modulation (QAM) mode, in addition to other usual configurations. The resource utilization and performance trade-off can be tuned by configuring different parameters of the IP core to obtain the optimal Spurious Free Dynamic Range (SFDR) result. The Lattice NCO core offers a variety of memory reduction schemes and mechanisms for SFDR improvement.