arm_pid_init_q15.c

00001 /* ----------------------------------------------------------------------
00002  * Project:      CMSIS DSP Library
00003  * Title:        arm_pid_init_q15.c
00004  * Description:  Q15 PID Control initialization function
00005  *
00006  * $Date:        27. January 2017
00007  * $Revision:    V.1.5.1
00008  *
00009  * Target Processor: Cortex-M cores
00010  * -------------------------------------------------------------------- */
00011 /*
00012  * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
00013  *
00014  * SPDX-License-Identifier: Apache-2.0
00015  *
00016  * Licensed under the Apache License, Version 2.0 (the License); you may
00017  * not use this file except in compliance with the License.
00018  * You may obtain a copy of the License at
00019  *
00020  * www.apache.org/licenses/LICENSE-2.0
00021  *
00022  * Unless required by applicable law or agreed to in writing, software
00023  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
00024  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00025  * See the License for the specific language governing permissions and
00026  * limitations under the License.
00027  */
00028 
00029 #include "arm_math.h"
00030 
00031  /**
00032  * @addtogroup PID
00033  * @{
00034  */
00035 
00036 /**
00037  * @details
00038  * @param[in,out] *S points to an instance of the Q15 PID structure.
00039  * @param[in]     resetStateFlag  flag to reset the state. 0 = no change in state 1 = reset the state.
00040  * @return none.
00041  * \par Description:
00042  * \par
00043  * The <code>resetStateFlag</code> specifies whether to set state to zero or not. \n
00044  * The function computes the structure fields: <code>A0</code>, <code>A1</code> <code>A2</code>
00045  * using the proportional gain( \c Kp), integral gain( \c Ki) and derivative gain( \c Kd)
00046  * also sets the state variables to all zeros.
00047  */
00048 
00049 void arm_pid_init_q15(
00050   arm_pid_instance_q15 * S,
00051   int32_t resetStateFlag)
00052 {
00053 
00054 #if defined (ARM_MATH_DSP)
00055 
00056   /* Run the below code for Cortex-M4 and Cortex-M3 */
00057 
00058   /* Derived coefficient A0 */
00059   S->A0 = __QADD16(__QADD16(S->Kp, S->Ki), S->Kd);
00060 
00061   /* Derived coefficients and pack into A1 */
00062 
00063 #ifndef  ARM_MATH_BIG_ENDIAN
00064 
00065   S->A1 = __PKHBT(-__QADD16(__QADD16(S->Kd, S->Kd), S->Kp), S->Kd, 16);
00066 
00067 #else
00068 
00069   S->A1 = __PKHBT(S->Kd, -__QADD16(__QADD16(S->Kd, S->Kd), S->Kp), 16);
00070 
00071 #endif /*      #ifndef  ARM_MATH_BIG_ENDIAN    */
00072 
00073   /* Check whether state needs reset or not */
00074   if (resetStateFlag)
00075   {
00076     /* Clear the state buffer.  The size will be always 3 samples */
00077     memset(S->state, 0, 3U * sizeof(q15_t));
00078   }
00079 
00080 #else
00081 
00082   /* Run the below code for Cortex-M0 */
00083 
00084   q31_t temp;                                    /*to store the sum */
00085 
00086   /* Derived coefficient A0 */
00087   temp = S->Kp + S->Ki + S->Kd;
00088   S->A0 = (q15_t) __SSAT(temp, 16);
00089 
00090   /* Derived coefficients and pack into A1 */
00091   temp = -(S->Kd + S->Kd + S->Kp);
00092   S->A1 = (q15_t) __SSAT(temp, 16);
00093   S->A2 = S->Kd;
00094 
00095 
00096 
00097   /* Check whether state needs reset or not */
00098   if (resetStateFlag)
00099   {
00100     /* Clear the state buffer.  The size will be always 3 samples */
00101     memset(S->state, 0, 3U * sizeof(q15_t));
00102   }
00103 
00104 #endif /* #if defined (ARM_MATH_DSP) */
00105 
00106 }
00107 
00108 /**
00109  * @} end of PID group
00110  */
00111