NCO IP Core: User Guide

ID 683406
Date 11/06/2017
Document Table of Contents

1. About the NCO IP Core

Updated for:
Intel® Quartus® Prime Design Suite 17.1
The Altera® NCO IP core generates numerically controlled oscillators (NCOs) customized for Intel devices. A numerically controlled oscillator (NCO) synthesizes a discrete-time, discrete-valued representation of a sinusoidal waveform.

Typically, you can use NCOs in communication systems as quadrature carrier generators in I-Q mixers, in which baseband data is modulated onto the orthogonal carriers in one of a variety of ways.

Figure 1. Simple Modulator

You can also use NCOs in all-digital phase-locked-loops (PLLs) for carrier synchronization in communications receivers, or as standalone frequency shift keying (FSK) or phase shift keying (PSK) modulators. In these applications, the phase or the frequency of the output waveform varies directly according to an input data stream.

You can implement ROM-based, CORDIC-based, and multiplier-based NCO architectures,. The wizard also includes time and frequency domain graphs that dynamically display the functionality of the NCO, based on your parameter settings.

To decide which NCO implementation to use, consider the spectral purity, frequency resolution, performance, throughput, and required device resources. Also, consider the trade-offs between some or all of these parameters.