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;
+      }
+           
+    }
+}
+
+
+
+