Oscillator

Overview

Numerically-controlled oscillator

Discussion

Implements a discrete-time oscillator by using the input signal to adjust the nominal frequency driving a sinusoid generator. The output is \(y[n] = \sin (omega_o nT + \sum_{k=0}^n x[k] + \phi)\) where \(\omega_o\) is the nominal frequency in radians/s, T is the sample period and \(\phi\) is the starting phase in radians (default is 0).

The internal variable freq caches the nominal frequency in units of radians/second. phase maintains the current phase in radians between blocks

Module Pack

Advanced

ClassID

classID = 1300

Type Definition

typedef struct _ModuleOscillator
{
ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
FLOAT32 freqhz;                               // Nominal oscillator frequency in Hz
FLOAT32 startPhase;                           // Starting phase oscillator in multiples of pi radians
FLOAT32 freq;                                 // Current oscillator frequency
FLOAT32* phase;                               // Current oscillator phase
} ModuleOscillatorClass;

Variables

Properties

Name	Type	Usage	isHidden	Default Value	Range	Units
freqhz	float	parameter	0	0	0:5000	Hz
startPhase	float	parameter	0	0	-1:1	x pi radians
freq	float	state	1	0	Unrestricted	radians/s
phase	float*	state	1	[1 x 1]	Unrestricted	radians

Pins

Input Pins


Name	control
Description	Frequency control input
Data type	float
Channel range	1
Block size range	Unrestricted
Sample rate range	Unrestricted
Complex support	Real

Output Pins


Name	out
Description	Oscillator output
Data Type	float

Matlab Usage

File Name: oscillator_module.m 
 This module implements a sinusiodal oscillator whose output frequency is 
 determined by the input signal. It is derived from the sine generator. 

 Arguments: 
   NAME - name of the module. 
   QUAD - true means the output is 2 channels in quadrature