text: /**
    ******************************************************************************
    * @file    stm32l1xx_hal_crc.c
    * @author  MCD Application Team
    * @brief   CRC HAL module driver.
    *          This file provides firmware functions to manage the following
    *          functionalities of the Cyclic Redundancy Check (CRC) peripheral:
    *           + Initialization and de-initialization functions
    *           + Peripheral Control functions
    *           + Peripheral State functions
    *
    @verbatim
   ===============================================================================
                       ##### How to use this driver #####
   ===============================================================================
      [..]
           (+) Enable CRC AHB clock using __HAL_RCC_CRC_CLK_ENABLE();
           (+) Initialize CRC calculator
               (++) specify generating polynomial (peripheral default or non-default one)
               (++) specify initialization value (peripheral default or non-default one)
               (++) specify input data format
               (++) specify input or output data inversion mode if any
           (+) Use HAL_CRC_Accumulate() function to compute the CRC value of the
               input data buffer starting with the previously computed CRC as
               initialization value
           (+) Use HAL_CRC_Calculate() function to compute the CRC value of the
               input data buffer starting with the defined initialization value
               (default or non-default) to initiate CRC calculation
  
    @endverbatim
    ******************************************************************************
    * @attention
    *
    * <h2><center>&copy; Copyright (c) 2017 STMicroelectronics.
    * All rights reserved.</center></h2>
    *
    * This software component is licensed by ST under BSD 3-Clause license,
    * the "License"; You may not use this file except in compliance with the
    * License. You may obtain a copy of the License at:
    *                        opensource.org/licenses/BSD-3-Clause
    *
    ******************************************************************************
    */
  
  /* Includes ------------------------------------------------------------------*/
  #include "stm32l1xx_hal.h"
  
  /** @addtogroup STM32L1xx_HAL_Driver
    * @{
    */
  
  /** @defgroup CRC CRC
    * @brief CRC HAL module driver.
    * @{
    */
  
  #ifdef HAL_CRC_MODULE_ENABLED
  
  /* Private typedef -----------------------------------------------------------*/
  /* Private define ------------------------------------------------------------*/
  /* Private macro -------------------------------------------------------------*/
  /* Private variables ---------------------------------------------------------*/
  /* Private function prototypes -----------------------------------------------*/
  
  /* Exported functions --------------------------------------------------------*/
  
  /** @defgroup CRC_Exported_Functions CRC Exported Functions
    * @{
    */
  
  /** @defgroup CRC_Exported_Functions_Group1 Initialization and de-initialization functions
   *  @brief    Initialization and Configuration functions.
   *
  @verbatim
   ===============================================================================
              ##### Initialization and de-initialization functions #####
   ===============================================================================
      [..]  This section provides functions allowing to:
        (+) Initialize the CRC according to the specified parameters
            in the CRC_InitTypeDef and create the associated handle
        (+) DeInitialize the CRC peripheral
        (+) Initialize the CRC MSP (MCU Specific Package)
        (+) DeInitialize the CRC MSP
  
  @endverbatim
    * @{
    */
  
  /**
    * @brief  Initialize the CRC according to the specified
    *         parameters in the CRC_InitTypeDef and create the associated handle.
    * @param  hcrc CRC handle
    * @retval HAL status
    */
  HAL_StatusTypeDef HAL_CRC_Init(CRC_HandleTypeDef *hcrc)
  {
    /* Check the CRC handle allocation */
    if (hcrc == NULL)
    {
      return HAL_ERROR;
    }
  
    /* Check the parameters */
    assert_param(IS_CRC_ALL_INSTANCE(hcrc->Instance));
  
    if (hcrc->State == HAL_CRC_STATE_RESET)
    {
      /* Allocate lock resource and initialize it */
      hcrc->Lock = HAL_UNLOCKED;
      /* Init the low level hardware */
      HAL_CRC_MspInit(hcrc);
    }
  
    /* Change CRC peripheral state */
    hcrc->State = HAL_CRC_STATE_READY;
  
    /* Return function status */
    return HAL_OK;
  }
  
  /**
    * @brief  DeInitialize the CRC peripheral.
    * @param  hcrc CRC handle
    * @retval HAL status
    */
  HAL_StatusTypeDef HAL_CRC_DeInit(CRC_HandleTypeDef *hcrc)
  {
    /* Check the CRC handle allocation */
    if (hcrc == NULL)
    {
      return HAL_ERROR;
    }
  
    /* Check the parameters */
    assert_param(IS_CRC_ALL_INSTANCE(hcrc->Instance));
  
    /* Check the CRC peripheral state */
    if (hcrc->State == HAL_CRC_STATE_BUSY)
    {
      return HAL_BUSY;
    }
  
    /* Change CRC peripheral state */
    hcrc->State = HAL_CRC_STATE_BUSY;
  
    /* Reset CRC calculation unit */
    __HAL_CRC_DR_RESET(hcrc);
  
    /* Reset IDR register content */
    CLEAR_BIT(hcrc->Instance->IDR, CRC_IDR_IDR);
  
    /* DeInit the low level hardware */
    HAL_CRC_MspDeInit(hcrc);
  
    /* Change CRC peripheral state */
    hcrc->State = HAL_CRC_STATE_RESET;
  
    /* Process unlocked */
    __HAL_UNLOCK(hcrc);
  
    /* Return function status */
    return HAL_OK;
  }
  
  /**
    * @brief  Initializes the CRC MSP.
    * @param  hcrc CRC handle
    * @retval None
    */
  __weak void HAL_CRC_MspInit(CRC_HandleTypeDef *hcrc)
  {
    /* Prevent unused argument(s) compilation warning */
    UNUSED(hcrc);
  
    /* NOTE : This function should not be modified, when the callback is needed,
              the HAL_CRC_MspInit can be implemented in the user file
     */
  }
  
  /**
    * @brief  DeInitialize the CRC MSP.
    * @param  hcrc CRC handle
    * @retval None
    */
  __weak void HAL_CRC_MspDeInit(CRC_HandleTypeDef *hcrc)
  {
    /* Prevent unused argument(s) compilation warning */
    UNUSED(hcrc);
  
    /* NOTE : This function should not be modified, when the callback is needed,
              the HAL_CRC_MspDeInit can be implemented in the user file
     */
  }
  
  /**
    * @}
    */
  
  /** @defgroup CRC_Exported_Functions_Group2 Peripheral Control functions
   *  @brief    management functions.
   *
  @verbatim
   ===============================================================================
                        ##### Peripheral Control functions #####
   ===============================================================================
      [..]  This section provides functions allowing to:
        (+) compute the 32-bit CRC value of a 32-bit data buffer
            using combination of the previous CRC value and the new one.
  
         [..]  or
  
        (+) compute the 32-bit CRC value of a 32-bit data buffer
            independently of the previous CRC value.
  
  @endverbatim
    * @{
    */
  
  /**
    * @brief  Compute the 32-bit CRC value of a 32-bit data buffer
    *         starting with the previously computed CRC as initialization value.
    * @param  hcrc CRC handle
    * @param  pBuffer pointer to the input data buffer.
    * @param  BufferLength input data buffer length (number of uint32_t words).
    * @retval uint32_t CRC (returned value LSBs for CRC shorter than 32 bits)
    */
  uint32_t HAL_CRC_Accumulate(CRC_HandleTypeDef *hcrc, uint32_t pBuffer[], uint32_t BufferLength)
  {
    uint32_t index;      /* CRC input data buffer index */
    uint32_t temp = 0U;  /* CRC output (read from hcrc->Instance->DR register) */
  
    /* Change CRC peripheral state */
    hcrc->State = HAL_CRC_STATE_BUSY;
  
    /* Enter Data to the CRC calculator */
    for (index = 0U; index < BufferLength; index++)
    {
      hcrc->Instance->DR = pBuffer[index];
    }
    temp = hcrc->Instance->DR;
  
    /* Change CRC peripheral state */
    hcrc->State = HAL_CRC_STATE_READY;
  
    /* Return the CRC computed value */
    return temp;
  }
  
  /**
    * @brief  Compute the 32-bit CRC value of a 32-bit data buffer
    *         starting with hcrc->Instance->INIT as initialization value.
    * @param  hcrc CRC handle
    * @param  pBuffer pointer to the input data buffer.
    * @param  BufferLength input data buffer length (number of uint32_t words).
    * @retval uint32_t CRC (returned value LSBs for CRC shorter than 32 bits)
    */
  uint32_t HAL_CRC_Calculate(CRC_HandleTypeDef *hcrc, uint32_t pBuffer[], uint32_t BufferLength)
  {
    uint32_t index;      /* CRC input data buffer index */
    uint32_t temp = 0U;  /* CRC output (read from hcrc->Instance->DR register) */
  
    /* Change CRC peripheral state */
    hcrc->State = HAL_CRC_STATE_BUSY;
  
    /* Reset CRC Calculation Unit (hcrc->Instance->INIT is
    *  written in hcrc->Instance->DR) */
    __HAL_CRC_DR_RESET(hcrc);
  
    /* Enter 32-bit input data to the CRC calculator */
    for (index = 0U; index < BufferLength; index++)
    {
      hcrc->Instance->DR = pBuffer[index];
    }
    temp = hcrc->Instance->DR;
  
    /* Change CRC peripheral state */
    hcrc->State = HAL_CRC_STATE_READY;
  
    /* Return the CRC computed value */
    return temp;
  }
  
  /**
    * @}
    */
  
  /** @defgroup CRC_Exported_Functions_Group3 Peripheral State functions
   *  @brief    Peripheral State functions.
   *
  @verbatim
   ===============================================================================
                        ##### Peripheral State functions #####
   ===============================================================================
      [..]
      This subsection permits to get in run-time the status of the peripheral.
  
  @endverbatim
    * @{
    */
  
  /**
    * @brief  Return the CRC handle state.
    * @param  hcrc CRC handle
    * @retval HAL state
    */
  HAL_CRC_StateTypeDef HAL_CRC_GetState(CRC_HandleTypeDef *hcrc)
  {
    /* Return CRC handle state */
    return hcrc->State;
  }
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  
  #endif /* HAL_CRC_MODULE_ENABLED */
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
  