Laxmi Kant Tiwari
CMSIS DSP Lib
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mbed official
Diff: cmsis_dsp/SupportFunctions/math_helper.c
- Revision:
- 1:fdd22bb7aa52
- Child:
- 2:da51fb522205
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/cmsis_dsp/SupportFunctions/math_helper.c Wed Nov 28 12:30:09 2012 +0000
@@ -0,0 +1,447 @@
+/* ----------------------------------------------------------------------
+* Copyright (C) 2010 ARM Limited. All rights reserved.
+*
+* $Date: 29. November 2010
+* $Revision: V1.0.3
+*
+* Project: CMSIS DSP Library
+*
+* Title: math_helper.c
+*
+* Description: Definition of all helper functions required.
+*
+* Target Processor: Cortex-M4/Cortex-M3
+*
+* Version 1.0.3 2010/11/29
+* Re-organized the CMSIS folders and updated documentation.
+*
+* Version 1.0.2 2010/11/11
+* Documentation updated.
+*
+* Version 1.0.1 2010/10/05
+* Production release and review comments incorporated.
+*
+* Version 1.0.0 2010/09/20
+* Production release and review comments incorporated.
+*
+* Version 0.0.7 2010/06/10
+* Misra-C changes done
+* -------------------------------------------------------------------- */
+
+/* ----------------------------------------------------------------------
+* Include standard header files
+* -------------------------------------------------------------------- */
+#include<math.h>
+
+/* ----------------------------------------------------------------------
+* Include project header files
+* -------------------------------------------------------------------- */
+#include "math_helper.h"
+
+/**
+ * @brief Caluclation of SNR
+ * @param float* Pointer to the reference buffer
+ * @param float* Pointer to the test buffer
+ * @param uint32_t total number of samples
+ * @return float SNR
+ * The function Caluclates signal to noise ratio for the reference output
+ * and test output
+ */
+
+float arm_snr_f32(float *pRef, float *pTest, uint32_t buffSize)
+{
+ float EnergySignal = 0.0, EnergyError = 0.0;
+ uint32_t i;
+ float SNR;
+ int temp;
+ int *test;
+
+ for (i = 0; i < buffSize; i++)
+ {
+ /* Checking for a NAN value in pRef array */
+ test = (int *)(&pRef[i]);
+ temp = *test;
+
+ if(temp == 0x7FC00000)
+ {
+ return(0);
+ }
+
+ /* Checking for a NAN value in pTest array */
+ test = (int *)(&pTest[i]);
+ temp = *test;
+
+ if(temp == 0x7FC00000)
+ {
+ return(0);
+ }
+ EnergySignal += pRef[i] * pRef[i];
+ EnergyError += (pRef[i] - pTest[i]) * (pRef[i] - pTest[i]);
+ }
+
+ /* Checking for a NAN value in EnergyError */
+ test = (int *)(&EnergyError);
+ temp = *test;
+
+ if(temp == 0x7FC00000)
+ {
+ return(0);
+ }
+
+
+ SNR = 10 * log10 (EnergySignal / EnergyError);
+
+ return (SNR);
+
+}
+
+
+/**
+ * @brief Provide guard bits for Input buffer
+ * @param q15_t* Pointer to input buffer
+ * @param uint32_t blockSize
+ * @param uint32_t guard_bits
+ * @return none
+ * The function Provides the guard bits for the buffer
+ * to avoid overflow
+ */
+
+void arm_provide_guard_bits_q15 (q15_t * input_buf, uint32_t blockSize,
+ uint32_t guard_bits)
+{
+ uint32_t i;
+
+ for (i = 0; i < blockSize; i++)
+ {
+ input_buf[i] = input_buf[i] >> guard_bits;
+ }
+}
+
+/**
+ * @brief Converts float to fixed in q12.20 format
+ * @param uint32_t number of samples in the buffer
+ * @return none
+ * The function converts floating point values to fixed point(q12.20) values
+ */
+
+void arm_float_to_q12_20(float *pIn, q31_t * pOut, uint32_t numSamples)
+{
+ uint32_t i;
+
+ for (i = 0; i < numSamples; i++)
+ {
+ /* 1048576.0f corresponds to pow(2, 20) */
+ pOut[i] = (q31_t) (pIn[i] * 1048576.0f);
+
+ pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
+
+ if (pIn[i] == (float) 1.0)
+ {
+ pOut[i] = 0x000FFFFF;
+ }
+ }
+}
+
+/**
+ * @brief Compare MATLAB Reference Output and ARM Test output
+ * @param q15_t* Pointer to Ref buffer
+ * @param q15_t* Pointer to Test buffer
+ * @param uint32_t number of samples in the buffer
+ * @return none
+ */
+
+uint32_t arm_compare_fixed_q15(q15_t *pIn, q15_t * pOut, uint32_t numSamples)
+{
+ uint32_t i;
+ int32_t diff, diffCrnt = 0;
+ uint32_t maxDiff = 0;
+
+ for (i = 0; i < numSamples; i++)
+ {
+ diff = pIn[i] - pOut[i];
+ diffCrnt = (diff > 0) ? diff : -diff;
+
+ if(diffCrnt > maxDiff)
+ {
+ maxDiff = diffCrnt;
+ }
+ }
+
+ return(maxDiff);
+}
+
+/**
+ * @brief Compare MATLAB Reference Output and ARM Test output
+ * @param q31_t* Pointer to Ref buffer
+ * @param q31_t* Pointer to Test buffer
+ * @param uint32_t number of samples in the buffer
+ * @return none
+ */
+
+uint32_t arm_compare_fixed_q31(q31_t *pIn, q31_t * pOut, uint32_t numSamples)
+{
+ uint32_t i;
+ int32_t diff, diffCrnt = 0;
+ uint32_t maxDiff = 0;
+
+ for (i = 0; i < numSamples; i++)
+ {
+ diff = pIn[i] - pOut[i];
+ diffCrnt = (diff > 0) ? diff : -diff;
+
+ if(diffCrnt > maxDiff)
+ {
+ maxDiff = diffCrnt;
+ }
+ }
+
+ return(maxDiff);
+}
+
+/**
+ * @brief Provide guard bits for Input buffer
+ * @param q31_t* Pointer to input buffer
+ * @param uint32_t blockSize
+ * @param uint32_t guard_bits
+ * @return none
+ * The function Provides the guard bits for the buffer
+ * to avoid overflow
+ */
+
+void arm_provide_guard_bits_q31 (q31_t * input_buf,
+ uint32_t blockSize,
+ uint32_t guard_bits)
+{
+ uint32_t i;
+
+ for (i = 0; i < blockSize; i++)
+ {
+ input_buf[i] = input_buf[i] >> guard_bits;
+ }
+}
+
+/**
+ * @brief Provide guard bits for Input buffer
+ * @param q31_t* Pointer to input buffer
+ * @param uint32_t blockSize
+ * @param uint32_t guard_bits
+ * @return none
+ * The function Provides the guard bits for the buffer
+ * to avoid overflow
+ */
+
+void arm_provide_guard_bits_q7 (q7_t * input_buf,
+ uint32_t blockSize,
+ uint32_t guard_bits)
+{
+ uint32_t i;
+
+ for (i = 0; i < blockSize; i++)
+ {
+ input_buf[i] = input_buf[i] >> guard_bits;
+ }
+}
+
+
+
+/**
+ * @brief Caluclates number of guard bits
+ * @param uint32_t number of additions
+ * @return none
+ * The function Caluclates the number of guard bits
+ * depending on the numtaps
+ */
+
+uint32_t arm_calc_guard_bits (uint32_t num_adds)
+{
+ uint32_t i = 1, j = 0;
+
+ if (num_adds == 1)
+ {
+ return (0);
+ }
+
+ while (i < num_adds)
+ {
+ i = i * 2;
+ j++;
+ }
+
+ return (j);
+}
+
+/**
+ * @brief Converts Q15 to floating-point
+ * @param uint32_t number of samples in the buffer
+ * @return none
+ */
+
+void arm_apply_guard_bits (float32_t * pIn,
+ uint32_t numSamples,
+ uint32_t guard_bits)
+{
+ uint32_t i;
+
+ for (i = 0; i < numSamples; i++)
+ {
+ pIn[i] = pIn[i] * arm_calc_2pow(guard_bits);
+ }
+}
+
+/**
+ * @brief Calculates pow(2, numShifts)
+ * @param uint32_t number of shifts
+ * @return pow(2, numShifts)
+ */
+uint32_t arm_calc_2pow(uint32_t numShifts)
+{
+
+ uint32_t i, val = 1;
+
+ for (i = 0; i < numShifts; i++)
+ {
+ val = val * 2;
+ }
+
+ return(val);
+}
+
+
+
+/**
+ * @brief Converts float to fixed q14
+ * @param uint32_t number of samples in the buffer
+ * @return none
+ * The function converts floating point values to fixed point values
+ */
+
+void arm_float_to_q14 (float *pIn, q15_t * pOut,
+ uint32_t numSamples)
+{
+ uint32_t i;
+
+ for (i = 0; i < numSamples; i++)
+ {
+ /* 16384.0f corresponds to pow(2, 14) */
+ pOut[i] = (q15_t) (pIn[i] * 16384.0f);
+
+ pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
+
+ if (pIn[i] == (float) 2.0)
+ {
+ pOut[i] = 0x7FFF;
+ }
+
+ }
+
+}
+
+
+/**
+ * @brief Converts float to fixed q30 format
+ * @param uint32_t number of samples in the buffer
+ * @return none
+ * The function converts floating point values to fixed point values
+ */
+
+void arm_float_to_q30 (float *pIn, q31_t * pOut,
+ uint32_t numSamples)
+{
+ uint32_t i;
+
+ for (i = 0; i < numSamples; i++)
+ {
+ /* 1073741824.0f corresponds to pow(2, 30) */
+ pOut[i] = (q31_t) (pIn[i] * 1073741824.0f);
+
+ pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
+
+ if (pIn[i] == (float) 2.0)
+ {
+ pOut[i] = 0x7FFFFFFF;
+ }
+ }
+}
+
+/**
+ * @brief Converts float to fixed q30 format
+ * @param uint32_t number of samples in the buffer
+ * @return none
+ * The function converts floating point values to fixed point values
+ */
+
+void arm_float_to_q29 (float *pIn, q31_t * pOut,
+ uint32_t numSamples)
+{
+ uint32_t i;
+
+ for (i = 0; i < numSamples; i++)
+ {
+ /* 1073741824.0f corresponds to pow(2, 30) */
+ pOut[i] = (q31_t) (pIn[i] * 536870912.0f);
+
+ pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
+
+ if (pIn[i] == (float) 4.0)
+ {
+ pOut[i] = 0x7FFFFFFF;
+ }
+ }
+}
+
+
+/**
+ * @brief Converts float to fixed q28 format
+ * @param uint32_t number of samples in the buffer
+ * @return none
+ * The function converts floating point values to fixed point values
+ */
+
+void arm_float_to_q28 (float *pIn, q31_t * pOut,
+ uint32_t numSamples)
+{
+ uint32_t i;
+
+ for (i = 0; i < numSamples; i++)
+ {
+ /* 268435456.0f corresponds to pow(2, 28) */
+ pOut[i] = (q31_t) (pIn[i] * 268435456.0f);
+
+ pOut[i] += pIn[i] > 0 ? 0.5 : -0.5;
+
+ if (pIn[i] == (float) 8.0)
+ {
+ pOut[i] = 0x7FFFFFFF;
+ }
+ }
+}
+
+/**
+ * @brief Clip the float values to +/- 1
+ * @param pIn input buffer
+ * @param numSamples number of samples in the buffer
+ * @return none
+ * The function converts floating point values to fixed point values
+ */
+
+void arm_clip_f32 (float *pIn, uint32_t numSamples)
+{
+ uint32_t i;
+
+ for (i = 0; i < numSamples; i++)
+ {
+ if(pIn[i] > 1.0f)
+ {
+ pIn[i] = 1.0;
+ }
+ else if( pIn[i] < -1.0f)
+ {
+ pIn[i] = -1.0;
+ }
+
+ }
+}
+
+
+
+