dds_float.c File Reference
`#include <stdio.h>`
`#include <inttypes.h>`
`#include "floating_fudge.h"`
`#include "spandsp/telephony.h"`
`#include "spandsp/complex.h"`
`#include "spandsp/dds.h"`

## Macros

#define | SLENK 11
#define | SINELEN (1 << SLENK)

## Functions

float | dds_phase_to_radians (uint32_t phase)
| Convert a 32 bit phase angle to an angle in radians, between 0 and 2*PI.
int32_t | dds_phase_ratef (float frequency)
| Find the phase rate equivalent to a frequency, in Hz.
float | dds_frequencyf (int32_t phase_rate)
| Find the frequency, in Hz, equivalent to a phase rate.
float | dds_scaling_dbm0f (float level)
| Find the scaling factor equivalent to a dBm0 value.
float | dds_scaling_dbovf (float level)
| Find the scaling factor equivalent to a dBmov value.
void | dds_advancef (uint32_t *phase_acc, int32_t phase_rate)
| Advance the phase, without returning any new signal sample.
float | ddsf (uint32_t *phase_acc, int32_t phase_rate)
| Generate a floating point tone sample.
float | dds_lookupf (uint32_t phase)
| Lookup the floating point value of a specified phase.
float | dds_modf (uint32_t *phase_acc, int32_t phase_rate, float scale, int32_t phase)
| Generate a floating point tone sample, with modulation.
complexf_t | dds_complexf (uint32_t *phase_acc, int32_t phase_rate)
| Generate a complex floating point tone sample.
complexf_t | dds_lookup_complexf (uint32_t phase)
| Lookup the complex value of a specified phase.
complexf_t | dds_complex_modf (uint32_t *phase_acc, int32_t phase_rate, float scale, int32_t phase)
| Generate a complex floating point tone sample, with modulation.

## Function Documentation

## dds_advancef()

void dds_advancef | ( | uint32_t * | phase_acc,
|  | int32_t | phase_rate )

Advance the phase, without returning any new signal sample.

Parameters

  phase_acc | A pointer to a phase accumulator value.
  phase_rate | The phase increment to be applied.

## dds_complex_modf()

complexf_t dds_complex_modf | ( | uint32_t * | phase_acc,
|  | int32_t | phase_rate,
|  | float | scale,
|  | int32_t | phase )

Generate a complex floating point tone sample, with modulation.

Parameters

  phase_acc | A pointer to a phase accumulator value.
  phase_rate | The phase increment to be applied.
  scale | The scaling factor.
  phase | The phase offset.

Returns
  The complex signal amplitude, between (-1.0, -1.0) and (1.0, 1.0).

## dds_complexf()

complexf_t dds_complexf | ( | uint32_t * | phase_acc,
|  | int32_t | phase_rate )

Generate a complex floating point tone sample.

Parameters

  phase_acc | A pointer to a phase accumulator value.
  phase_rate | The phase increment to be applied.

Returns
  The complex signal amplitude, between (-1.0, -1.0) and (1.0, 1.0).

## dds_frequencyf()

float dds_frequencyf | ( | int32_t | phase_rate | ) |

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

Parameters

  phase_rate | The phase rate.

Returns
  The equivalent frequency, in Hz.

Referenced by v17_rx_carrier_frequency(), v17_rx_restart(), v22bis_rx_carrier_frequency(), v27ter_rx_carrier_frequency(), and v29_rx_carrier_frequency().

## dds_lookup_complexf()

complexf_t dds_lookup_complexf | ( | uint32_t | phase_acc | ) |

Lookup the complex value of a specified phase.

Parameters

  phase | The phase accumulator value to be looked up.

Returns
  The complex signal amplitude, between (-1.0, -1.0) and (1.0, 1.0).

## dds_lookupf()

float dds_lookupf | ( | uint32_t | phase | ) |

Lookup the floating point value of a specified phase.

Parameters

  phase | The phase accumulator value to be looked up.

Returns
  The signal amplitude, between -1.0 and 1.0.

## dds_modf()

float dds_modf | ( | uint32_t * | phase_acc,
|  | int32_t | phase_rate,
|  | float | scale,
|  | int32_t | phase )

Generate a floating point tone sample, with modulation.

Parameters

  phase_acc | A pointer to a phase accumulator value.
  phase_rate | The phase increment to be applied.
  scale | The scaling factor.
  phase | The phase offset.

Returns
  The signal amplitude, between -1.0 and 1.0.

Referenced by super_tone_tx().

## dds_phase_ratef()

int32_t dds_phase_ratef | ( | float | frequency | ) |

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

Parameters

  frequency | The frequency, in Hz.

Returns
  The equivalent phase rate.

Referenced by tone_gen_descriptor_init(), v17_tx_init(), v22bis_init(), v22bis_rx_restart(), v22bis_tx_power(), and v27ter_tx_init().

## dds_phase_to_radians()

float dds_phase_to_radians | ( | uint32_t | phase | ) |

Convert a 32 bit phase angle to an angle in radians, between 0 and 2*PI.

Parameters

  phase | The angle to convert.

Returns
  The angle in radians.

## dds_scaling_dbm0f()

float dds_scaling_dbm0f | ( | float | level | ) |

Find the scaling factor equivalent to a dBm0 value.

Parameters

  level | The signal level in dBm0.

Returns
  The equivalent scaling factor.

Referenced by dtmf_tx_set_level(), and tone_gen_descriptor_init().

## dds_scaling_dbovf()

float dds_scaling_dbovf | ( | float | level | ) |

Find the scaling factor equivalent to a dBmov value.

Parameters

  level | The signal level in dBmov.

Returns
  The equivalent scaling factor.

## ddsf()

float ddsf | ( | uint32_t * | phase_acc,
|  | int32_t | phase_rate )

Generate a floating point tone sample.

Parameters

  phase_acc | A pointer to a phase accumulator value.
  phase_rate | The phase increment to be applied.

Returns
  The signal amplitude, between -1.0 and 1.0.