arm_pid_init_q31.c

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/* ----------------------------------------------------------------------    
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
*    
* $Date:        19. March 2015
* $Revision:    V.1.4.5
*    
* Project:      CMSIS DSP Library    
* Title:        arm_pid_init_q31.c    
*    
* Description:  Q31 PID Control initialization function     
*    
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*  
* Redistribution and use in source and binary forms, with or without 
* modification, are permitted provided that the following conditions
* are met:
*   - Redistributions of source code must retain the above copyright
*     notice, this list of conditions and the following disclaimer.
*   - Redistributions in binary form must reproduce the above copyright
*     notice, this list of conditions and the following disclaimer in
*     the documentation and/or other materials provided with the 
*     distribution.
*   - Neither the name of ARM LIMITED nor the names of its contributors
*     may be used to endorse or promote products derived from this
*     software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* ------------------------------------------------------------------- */

#include "arm_math.h"

void arm_pid_init_q31(
  arm_pid_instance_q31 * S,
  int32_t resetStateFlag)
{

#ifndef ARM_MATH_CM0_FAMILY

  /* Run the below code for Cortex-M4 and Cortex-M3 */

  /* Derived coefficient A0 */
  S->A0 = __QADD(__QADD(S->Kp, S->Ki), S->Kd);

  /* Derived coefficient A1 */
  S->A1 = -__QADD(__QADD(S->Kd, S->Kd), S->Kp);


#else

  /* Run the below code for Cortex-M0 */

  q31_t temp;

  /* Derived coefficient A0 */
  temp = clip_q63_to_q31((q63_t) S->Kp + S->Ki);
  S->A0 = clip_q63_to_q31((q63_t) temp + S->Kd);

  /* Derived coefficient A1 */
  temp = clip_q63_to_q31((q63_t) S->Kd + S->Kd);
  S->A1 = -clip_q63_to_q31((q63_t) temp + S->Kp);

#endif /* #ifndef ARM_MATH_CM0_FAMILY */

  /* Derived coefficient A2 */
  S->A2 = S->Kd;

  /* Check whether state needs reset or not */
  if(resetStateFlag)
  {
    /* Clear the state buffer.  The size will be always 3 samples */
    memset(S->state, 0, 3u * sizeof(q31_t));
  }

}