SineGenFract32

Overview

Sine wave generator

Discussion

Sine wave generator, with parameters for controlling frequency and start phase. The module requires setting sample rate and blocksize as input arguments. If the module is instantiated with the optional ISQUAD set to 1, the module will act as a quadrature sine oscillator, with the single output pin sending out the quadrature signal in interleaved form. In quadrature mode, the output contains two interleaved channels. The first channel represents the real portion of the oscillator (cosine) and the second channel represents the imaginary portion (sine). When using the quadrature output, a Deinterleave module can be used following the module to separate the sine and cosine outputs.

Internally, the module uses complex rotation around the unit circle to achieve the sine and cosine outputs. The complex vector [stateReal stateImag] has unity magnitude and is repeatedly multiplied by another unity magnitude complex vector [incReal incImag]. [stateReal stateImag] represents the instantaneous phase with stateReal representing the cosine output and stateImag representing the sine output. The initial values of [stateReal and stateImag] are determined by the startPhase parameter. startPhase is specified in degrees. The rotation vector [incReal incImag] determines the frequency of the oscillator: \(\mathrm{incReal} + j \mathrm{incImag} = e^{\frac{j 2 \pi \mathrm{freq}}{\mathrm{sampleRate}}}\)

Module Pack

Standard

ClassID

classID = 195

Type Definition

typedef struct _ModuleSineGenFract32
{
ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
FLOAT32 freq;                                 // Target frequency of the sine wave
FLOAT32 startPhase;                           // Starting phase of the sine wave
fract32 stateReal;                            // Real part of the complex unity magnitude state variable
fract32 stateImag;                            // Imaginary part of the complex unity magnitude state variable
fract32 incReal;                              // Real part of the complex unity magnitude multiplier
fract32 incImag;                              // Imaginary part of the complex unity magnitude multiplier
} ModuleSineGenFract32Class;

Variables

Properties

Name	Type	Usage	isHidden	Default Value	Range	Units
freq	float	parameter	0	1000	20:24000	Hz
startPhase	float	parameter	0	0	0:360	degrees
stateReal	fract32	parameter	1	1	Unrestricted
stateImag	fract32	parameter	1	0	Unrestricted
incReal	fract32	derived	1	0.99144	Unrestricted
incImag	fract32	derived	1	0.13053	Unrestricted

Pins

Output Pins


Name	out
Description	audio output
Data Type	fract32

Matlab Usage

File Name: sine_gen_fract32_module.m 
 M=sine_gen_fract32_module(NAME, SR, BLOCKSIZE, ISQUAD) 
 Creates a sine wave generator for use in the Audio Weaver.  This 
 module has a single 1 channel output pin with controllable frequency. 
 The output of the module changes instantly when the frequency is 
 updated.  Arguments: 
    NAME - name of the module. 
    SR - sample rate 
    BLOCKSIZE - number of samples per output channel. 
    ISQUAD - Boolean specifies that this is a quadrature oscillator with 
    two separate output pins. The first output pin is the cosine portion 
    and the second output pin is the sine portion. Default = 0.