arm_pid_init_q15.c

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/* ----------------------------------------------------------------------      
* Copyright (C) 2011 ARM Limited. All rights reserved. 
*      
* $Date:        15. December 2011   
* $Revision:    V2.0.0  
*      
* Project:      Cortex-R DSP Library 
* Title:        arm_pid_init_q15.c      
*      
* Description:  Q15 PID Control initialization function      
*      
* Target Processor:          Cortex-R4/R5
*
* Version 1.0.0 2011/03/08
*     Alpha release.
*
* Version 1.0.1 2011/09/30
*     Beta release.
*
* Version 2.0.0 2011/12/15
*     Final release. 
* 
* -------------------------------------------------------------------- */     
#include "arm_math.h"     
     
void arm_pid_init_q15(      
  arm_pid_instance_q15 * S,      
  int32_t resetStateFlag)      
{      
  /* Derived coefficient A0 */      
  S->A0 = __QADD16(__QADD16(S->Kp, S->Ki), S->Kd);      
      
  /* Derived coefficients and pack into A1 */      
#ifndef  ARM_MATH_BIG_ENDIAN   
  S->A1 = __PKHBT(-__QADD16(__QADD16(S->Kd, S->Kd), S->Kp), S->Kd, 16);      
      
#else   
   
  S->A1 = __PKHBT(S->Kd, -__QADD16(__QADD16(S->Kd, S->Kd), S->Kp), 16);   
   
#endif /*      #ifndef  ARM_MATH_BIG_ENDIAN    */   
  /* 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(q15_t));      
  }      
      
}