spandsp 0.0.6
dds_int.c File Reference
#include <inttypes.h>
#include "floating_fudge.h"
#include "spandsp/telephony.h"
#include "spandsp/complex.h"
#include "spandsp/dds.h"

Macros

#define SLENK   8
#define DDS_STEPS   (1 << SLENK)
#define DDS_SHIFT   (32 - 2 - SLENK)

Functions

int32_t dds_phase_rate (float frequency)
 Find the phase rate value to achieve a particular frequency.
float dds_frequency (int32_t phase_rate)
 Find the frequency, in Hz, equivalent to a phase rate.
int16_t dds_scaling_dbm0 (float level)
 Find the scaling factor needed to achieve a specified level in dBm0.
int16_t dds_scaling_dbov (float level)
 Find the scaling factor needed to achieve a specified level in dBmov.
int16_t dds_lookup (uint32_t phase)
 Lookup the integer value of a specified phase.
int16_t dds_offset (uint32_t phase_acc, int32_t phase_offset)
 Find the amplitude for a particular phase offset from an accumulated phase.
void dds_advance (uint32_t *phase_acc, int32_t phase_rate)
 Advance the phase, without returning any new signal sample.
int16_t dds (uint32_t *phase_acc, int32_t phase_rate)
 Generate an integer tone sample.
int16_t dds_mod (uint32_t *phase_acc, int32_t phase_rate, int16_t scale, int32_t phase)
 Generate an integer tone sample, with modulation.
complexi_t dds_lookup_complexi (uint32_t phase)
 Lookup the complex integer value of a specified phase.
complexi_t dds_complexi (uint32_t *phase_acc, int32_t phase_rate)
 Generate a complex integer tone sample.
complexi_t dds_complexi_mod (uint32_t *phase_acc, int32_t phase_rate, int16_t scale, int32_t phase)
 Generate a complex integer tone sample, with modulation.
complexi16_t dds_lookup_complexi16 (uint32_t phase)
 Generate a complex 16 bit integer tone sample.
complexi16_t dds_complexi16 (uint32_t *phase_acc, int32_t phase_rate)
 Generate a complex 16 bit integer tone sample.
complexi16_t dds_complexi16_mod (uint32_t *phase_acc, int32_t phase_rate, int16_t scale, int32_t phase)
 Generate a complex 16bit integer tone sample, with modulation.
complexi32_t dds_lookup_complexi32 (uint32_t phase)
 Generate a complex 32 bit integer tone sample.
complexi32_t dds_complexi32 (uint32_t *phase_acc, int32_t phase_rate)
 Generate a complex 32 bit integer tone sample.
complexi32_t dds_complexi32_mod (uint32_t *phase_acc, int32_t phase_rate, int16_t scale, int32_t phase)
 Generate a complex 32 bit integer tone sample, with modulation.

Function Documentation

◆ dds()

int16_t dds ( uint32_t * phase_acc,
int32_t phase_rate )

Generate an integer tone sample.

Parameters
phase_accA pointer to a phase accumulator value.
phase_rateThe phase increment to be applied.
Returns
The signal amplitude, between -32767 and 32767.

References dds_lookup().

◆ dds_advance()

void dds_advance ( uint32_t * phase_acc,
int32_t phase_rate )

Advance the phase, without returning any new signal sample.

Parameters
phase_accA pointer to a phase accumulator value.
phase_rateThe phase increment to be applied.

◆ dds_complexi()

complexi_t dds_complexi ( uint32_t * phase_acc,
int32_t phase_rate )

Generate a complex integer tone sample.

Parameters
phase_accA pointer to a phase accumulator value.
phase_rateThe phase increment to be applied.
Returns
The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

◆ dds_complexi16()

complexi16_t dds_complexi16 ( uint32_t * phase_acc,
int32_t phase_rate )

Generate a complex 16 bit integer tone sample.

Parameters
phase_accA pointer to a phase accumulator value.
phase_rateThe phase increment to be applied.
Returns
The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

◆ dds_complexi16_mod()

complexi16_t dds_complexi16_mod ( uint32_t * phase_acc,
int32_t phase_rate,
int16_t scale,
int32_t phase )

Generate a complex 16bit integer tone sample, with modulation.

Parameters
phase_accA pointer to a phase accumulator value.
phase_rateThe phase increment to be applied.
scaleThe scaling factor.
phaseThe phase offset.
Returns
The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

◆ dds_complexi32()

complexi32_t dds_complexi32 ( uint32_t * phase_acc,
int32_t phase_rate )

Generate a complex 32 bit integer tone sample.

Parameters
phase_accA pointer to a phase accumulator value.
phase_rateThe phase increment to be applied.
Returns
The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

◆ dds_complexi32_mod()

complexi32_t dds_complexi32_mod ( uint32_t * phase_acc,
int32_t phase_rate,
int16_t scale,
int32_t phase )

Generate a complex 32 bit integer tone sample, with modulation.

Parameters
phase_accA pointer to a phase accumulator value.
phase_rateThe phase increment to be applied.
scaleThe scaling factor.
phaseThe phase offset.
Returns
The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

◆ dds_complexi_mod()

complexi_t dds_complexi_mod ( uint32_t * phase_acc,
int32_t phase_rate,
int16_t scale,
int32_t phase )

Generate a complex integer tone sample, with modulation.

Parameters
phase_accA pointer to a phase accumulator value.
phase_rateThe phase increment to be applied.
scaleThe scaling factor.
phaseThe phase offset.
Returns
The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

◆ dds_frequency()

float dds_frequency ( int32_t phase_rate)

Find the frequency, in Hz, equivalent to a phase rate.

Parameters
phase_rateThe phase rate.
Returns
The equivalent frequency, in Hz.

◆ dds_lookup()

int16_t dds_lookup ( uint32_t phase)

Lookup the integer value of a specified phase.

Find the amplitude for a particular phase.

Parameters
phaseThe phase accumulator value to be looked up.
Returns
The signal amplitude, between -32767 and 32767.

Referenced by dds(), dds_complexi(), dds_complexi16(), dds_complexi16_mod(), dds_complexi32(), dds_complexi32_mod(), dds_complexi_mod(), dds_lookup_complexi(), dds_lookup_complexi16(), dds_lookup_complexi32(), dds_mod(), and dds_offset().

◆ dds_lookup_complexi()

complexi_t dds_lookup_complexi ( uint32_t phase)

Lookup the complex integer value of a specified phase.

Parameters
phaseThe phase accumulator value to be looked up.
Returns
The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

◆ dds_lookup_complexi16()

complexi16_t dds_lookup_complexi16 ( uint32_t phase)

Generate a complex 16 bit integer tone sample.

Parameters
phase_accA pointer to a phase accumulator value.
phase_rateThe phase increment to be applied.
Returns
The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

◆ dds_lookup_complexi32()

complexi32_t dds_lookup_complexi32 ( uint32_t phase)

Generate a complex 32 bit integer tone sample.

Parameters
phase_accA pointer to a phase accumulator value.
phase_rateThe phase increment to be applied.
Returns
The complex signal amplitude, between (-32767, -32767) and (32767, 32767).

References dds_lookup().

◆ dds_mod()

int16_t dds_mod ( uint32_t * phase_acc,
int32_t phase_rate,
int16_t scale,
int32_t phase )

Generate an integer tone sample, with modulation.

Parameters
phase_accA pointer to a phase accumulator value.
phase_rateThe phase increment to be applied.
scaleThe scaling factor.
phaseThe phase offset.
Returns
The signal amplitude, between -32767 and 32767.

References dds_lookup().

Referenced by sig_tone_tx().

◆ dds_offset()

int16_t dds_offset ( uint32_t phase_acc,
int32_t phase_offset )

Find the amplitude for a particular phase offset from an accumulated phase.

Parameters
phase_accThe accumulated phase.
phase_offsetThe phase offset.
Returns
The signal amplitude.

References dds_lookup().

◆ dds_phase_rate()

int32_t dds_phase_rate ( float frequency)

Find the phase rate value to achieve a particular frequency.

Parameters
frequencyThe desired frequency, in Hz.
Returns
The phase rate which while achieve the desired frequency.

Referenced by modem_connect_tones_tx_init(), sig_tone_tx_init(), and tone_gen_descriptor_init().

◆ dds_scaling_dbm0()

int16_t dds_scaling_dbm0 ( float level)

Find the scaling factor needed to achieve a specified level in dBm0.

Parameters
levelThe desired signal level, in dBm0.
Returns
The scaling factor.

Referenced by fsk_tx_power(), modem_connect_tones_tx_init(), sig_tone_tx_init(), and tone_gen_descriptor_init().

◆ dds_scaling_dbov()

int16_t dds_scaling_dbov ( float level)

Find the scaling factor needed to achieve a specified level in dBmov.

Parameters
levelThe desired signal level, in dBmov.
Returns
The scaling factor.