text: /* ----------------------------------------------------------------------    
  * 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_f32.c    
  *    
  * Description:	Floating-point 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
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * 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;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE. 
  
   Modifications 2017  Mostafa Saleh       (Ported to RISC-V PULPino)  
  * ------------------------------------------------------------------- */
  
  #include <riscv_dsp/riscv_math.h>
  
   /**    
   * @addtogroup PID    
   * @{    
   */
  
  /**    
   * @brief  Initialization function for the floating-point PID Control.   
   * @param[in,out] *S points to an instance of the PID structure.   
   * @param[in]     resetStateFlag  flag to reset the state. 0 = no change in state & 1 = reset the state.   
   * @return none.   
   * \par Description:   
   * \par    
   * The <code>resetStateFlag</code> specifies whether to set state to zero or not. \n   
   * The function computes the structure fields: <code>A0</code>, <code>A1</code> <code>A2</code>    
   * using the proportional gain( \c Kp), integral gain( \c Ki) and derivative gain( \c Kd)    
   * also sets the state variables to all zeros.    
   */
  
  void riscv_pid_init_f32(
    riscv_pid_instance_f32 * S,
    int32_t resetStateFlag)
  {
  
    /* Derived coefficient A0 */
    S->A0 = S->Kp + S->Ki + S->Kd;
  
    /* Derived coefficient A1 */
    S->A1 = (-S->Kp) - ((float32_t) 2.0 * S->Kd);
  
    /* 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(float32_t));
    }
  
  }
  
  /**    
   * @} end of PID group    
   */
  