dds.h

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00001 /*
00002  * SpanDSP - a series of DSP components for telephony
00003  *
00004  * dds.h
00005  *
00006  * Written by Steve Underwood <steveu@coppice.org>
00007  *
00008  * Copyright (C) 2003 Steve Underwood
00009  *
00010  * All rights reserved.
00011  *
00012  * This program is free software; you can redistribute it and/or modify
00013  * it under the terms of the GNU General Public License version 2, as
00014  * published by the Free Software Foundation.
00015  *
00016  * This program is distributed in the hope that it will be useful,
00017  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00018  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00019  * GNU General Public License for more details.
00020  *
00021  * You should have received a copy of the GNU General Public License
00022  * along with this program; if not, write to the Free Software
00023  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
00024  *
00025  * $Id: dds.h,v 1.13 2007/05/07 13:11:47 steveu Exp $
00026  */
00027 
00028 /*! \file */
00029 
00030 #if !defined(_SPANDSP_DDS_H_)
00031 #define _SPANDSP_DDS_H_
00032 
00033 #include "complex.h"
00034 
00035 #if defined(__cplusplus)
00036 extern "C"
00037 {
00038 #endif
00039 
00040 /*! \brief Find the phase rate value to achieve a particular frequency.
00041     \param frequency The desired frequency, in Hertz.
00042     \return The phase rate which while achieve the desired frequency.
00043 */
00044 int32_t dds_phase_rate(float frequency);
00045 
00046 float dds_frequency(int32_t phase_rate);
00047 
00048 /*! \brief Find the scaling factor needed to achieve a specified level in dBm0.
00049     \param level The desired signal level, in dBm0.
00050     \return The scaling factor.
00051 */
00052 int dds_scaling_dbm0(float level);
00053 
00054 int dds_scaling_dbov(float level);
00055 
00056 /*! \brief Find the amplitude for a particular phase.
00057     \param phase The desired phase 32 bit phase.
00058     \return The signal amplitude.
00059 */
00060 int16_t dds_lookup(uint32_t phase);
00061 
00062 /*! \brief Find the amplitude for a particular phase offset from an accumulated phase.
00063     \param phase_acc The accumulated phase.
00064     \param phase_offset The phase offset.
00065     \return The signal amplitude.
00066 */
00067 int16_t dds_offset(uint32_t phase_acc, int32_t phase_offset);
00068 
00069 /*! \brief Generate an integer tone sample.
00070     \param phase_acc A pointer to a phase accumulator value.
00071     \param phase_rate The phase increment to be applied.
00072     \return The signal amplitude, between -32767 and 32767.
00073 */
00074 int16_t dds(uint32_t *phase_acc, int32_t phase_rate);
00075 
00076 /*! \brief Generate an integer tone sample, with modulation.
00077     \param phase_acc A pointer to a phase accumulator value.
00078     \param phase_rate The phase increment to be applied.
00079     \param scale The scaling factor.
00080     \param phase The phase offset.
00081     \return The signal amplitude.
00082 */
00083 int16_t dds_mod(uint32_t *phase_acc, int32_t phase_rate, int scale, int32_t phase);
00084 
00085 /*! \brief Generate a complex integer tone sample.
00086     \param phase_acc A pointer to a phase accumulator value.
00087     \param phase_rate The phase increment to be applied.
00088     \return The complex signal amplitude, between -32767 and 32767.
00089 */
00090 complexi_t dds_complexi(uint32_t *phase_acc, int32_t phase_rate);
00091 
00092 /*! \brief Generate a complex integer tone sample, with modulation.
00093     \param phase_acc A pointer to a phase accumulator value.
00094     \param phase_rate The phase increment to be applied.
00095     \param scale The scaling factor.
00096     \param phase The phase offset.
00097     \return The complex signal amplitude.
00098 */
00099 complexi_t dds_complexi_mod(uint32_t *phase_acc, int32_t phase_rate, int scale, int32_t phase);
00100 
00101 int32_t dds_phase_ratef(float frequency);
00102 
00103 float dds_frequencyf(int32_t phase_rate);
00104 
00105 float dds_scaling_dbm0f(float level);
00106 
00107 float dds_scaling_dbovf(float level);
00108 
00109 /*! \brief Generate a floating point tone sample.
00110     \param phase_acc A pointer to a phase accumulator value.
00111     \param phase_rate The phase increment to be applied.
00112     \return The signal amplitude, between -32767 and 32767.
00113 */
00114 float ddsf(uint32_t *phase_acc, int32_t phase_rate);
00115 
00116 /*! \brief Generate a floating point tone sample, with modulation.
00117     \param phase_acc A pointer to a phase accumulator value.
00118     \param phase_rate The phase increment to be applied.
00119     \param scale The scaling factor.
00120     \param phase The phase offset.
00121     \return The signal amplitude.
00122 */
00123 float dds_modf(uint32_t *phase_acc, int32_t phase_rate, float scale, int32_t phase);
00124 
00125 /*! \brief Generate a complex floating point tone sample.
00126     \param phase_acc A pointer to a phase accumulator value.
00127     \param phase_rate The phase increment to be applied.
00128     \return The complex signal amplitude, between -32767 and 32767.
00129 */
00130 complexf_t dds_complexf(uint32_t *phase_acc, int32_t phase_rate);
00131 
00132 /*! \brief Generate a complex floating point tone sample, with modulation.
00133     \param phase_acc A pointer to a phase accumulator value.
00134     \param phase_rate The phase increment to be applied.
00135     \param scale The scaling factor.
00136     \param phase The phase offset.
00137     \return The complex signal amplitude.
00138 */
00139 complexf_t dds_complex_modf(uint32_t *phase_acc, int32_t phase_rate, float scale, int32_t phase);
00140 
00141 #if defined(__cplusplus)
00142 }
00143 #endif
00144 
00145 #endif
00146 /*- End of file ------------------------------------------------------------*/

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