/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file    Examples_LL/CRC/CRC_UserDefinedPolynomial/Src/main.c
  * @author  MCD Application Team
  * @brief   This example describes how to use CRC peripheral for generating 8-bit CRC value
  *          for an input data Buffer, based on a user defined polynomial value,
  *          using the STM32WLxx CRC LL API.
  *          Peripheral initialization done using LL unitary services functions.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2020 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
#define BUFFER_SIZE    39   /* 9 u32 + 1 u16 + 1 u8 */

/* 8-bit long user defined Polynomial value for this example
   In this example, the polynomial is set manually to 0x9B
   that is X^8 + X^7 + X^4 + X^3 + X + 1. */
#define  CRC8_POLYNOMIAL_VALUE    0x9B

/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/

/* USER CODE BEGIN PV */
/* Used for storing CRC Value */
__IO uint8_t ubCRCValue = 0;


static const uint8_t aDataBuffer[BUFFER_SIZE] =
{
  0x21, 0x10, 0x00, 0x00, 0x63, 0x30, 0x42, 0x20, 0xa5, 0x50, 0x84, 0x40,
  0xe7, 0x70, 0xc6, 0x60, 0x4a, 0xa1, 0x29, 0x91, 0x8c, 0xc1, 0x6b, 0xb1,
  0xce, 0xe1, 0xad, 0xd1, 0x31, 0x12, 0xef, 0xf1, 0x52, 0x22, 0x73, 0x32,
  0xa1, 0xb2, 0xc3
};

/* Expected CRC Value */
uint8_t ubExpectedCRCValue = 0x0C;

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_CRC_Init(void);
/* USER CODE BEGIN PFP */
uint8_t  Calculate_CRC(uint32_t);
void     CheckCRCResultValue(void);
void     LED_On(void);
void     LED_Blinking(uint32_t Period);
/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */


  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */

  /* System interrupt init*/
  NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_4);

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_CRC_Init();
  /* USER CODE BEGIN 2 */

  /* Perform CRC calculation on data contained in aDataBuffer */
  ubCRCValue = Calculate_CRC(BUFFER_SIZE);

  /* Check if CRC computed result value is equal to expected one */
  CheckCRCResultValue();

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  LL_FLASH_SetLatency(LL_FLASH_LATENCY_2);
  while(LL_FLASH_GetLatency() != LL_FLASH_LATENCY_2)
  {
  }

  LL_PWR_SetRegulVoltageScaling(LL_PWR_REGU_VOLTAGE_SCALE1);
  LL_RCC_MSI_Enable();

   /* Wait till MSI is ready */
  while(LL_RCC_MSI_IsReady() != 1)
  {
  }

  LL_RCC_MSI_EnableRangeSelection();
  LL_RCC_MSI_SetRange(LL_RCC_MSIRANGE_11);
  LL_RCC_MSI_SetCalibTrimming(0);
  LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_MSI);

   /* Wait till System clock is ready */
  while(LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_MSI)
  {
  }

  LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_1);
  LL_RCC_SetAHB3Prescaler(LL_RCC_SYSCLK_DIV_1);
  LL_RCC_SetAPB1Prescaler(LL_RCC_APB1_DIV_1);
  LL_RCC_SetAPB2Prescaler(LL_RCC_APB2_DIV_1);

  LL_Init1msTick(48000000);

  /* Update CMSIS variable (which can be updated also through SystemCoreClockUpdate function) */
  LL_SetSystemCoreClock(48000000);
}

/**
  * @brief CRC Initialization Function
  * @param None
  * @retval None
  */
static void MX_CRC_Init(void)
{

  /* USER CODE BEGIN CRC_Init 0 */

  /* USER CODE END CRC_Init 0 */

  /* Peripheral clock enable */
  LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_CRC);

  /* USER CODE BEGIN CRC_Init 1 */

  /* USER CODE END CRC_Init 1 */
  LL_CRC_SetInputDataReverseMode(CRC, LL_CRC_INDATA_REVERSE_NONE);
  LL_CRC_SetOutputDataReverseMode(CRC, LL_CRC_OUTDATA_REVERSE_NONE);
  LL_CRC_SetPolynomialCoef(CRC, LL_CRC_DEFAULT_CRC32_POLY);
  LL_CRC_SetPolynomialSize(CRC, LL_CRC_POLYLENGTH_32B);
  LL_CRC_SetInitialData(CRC, LL_CRC_DEFAULT_CRC_INITVALUE);
  /* USER CODE BEGIN CRC_Init 2 */

  /* Configure CRC calculation unit with user defined polynomial value, 8-bit long */
  LL_CRC_SetPolynomialCoef(CRC, CRC8_POLYNOMIAL_VALUE);
  LL_CRC_SetPolynomialSize(CRC, LL_CRC_POLYLENGTH_8B);

  /* USER CODE END CRC_Init 2 */

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  LL_GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* GPIO Ports Clock Enable */
  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOB);

  /**/
  LL_GPIO_ResetOutputPin(LED2_GPIO_Port, LED2_Pin);

  /**/
  GPIO_InitStruct.Pin = LED2_Pin;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_OUTPUT;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  LL_GPIO_Init(LED2_GPIO_Port, &GPIO_InitStruct);

}

/* USER CODE BEGIN 4 */

/**
  * @brief  This function performs CRC calculation on BufferSize bytes from input data buffer aDataBuffer.
  * @param  BufferSize Nb of bytes to be processed for CRC calculation
  * @retval 8-bit CRC value computed on input data buffer
  */
uint8_t Calculate_CRC(uint32_t BufferSize)
{
  register uint32_t data = 0;
  register uint32_t index = 0;

  /* Compute the CRC of Data Buffer array*/
  for (index = 0; index < (BufferSize / 4); index++)
  {
    data = (uint32_t)((aDataBuffer[4 * index] << 24) | (aDataBuffer[4 * index + 1] << 16) | (aDataBuffer[4 * index + 2] << 8) | aDataBuffer[4 * index + 3]);
    LL_CRC_FeedData32(CRC, data);
  }

  /* Last bytes specific handling */
  if ((BUFFER_SIZE % 4) != 0)
  {
    if (BUFFER_SIZE % 4 == 1)
    {
      LL_CRC_FeedData8(CRC, aDataBuffer[4 * index]);
    }
    if (BUFFER_SIZE % 4 == 2)
    {
      LL_CRC_FeedData16(CRC, (uint16_t)((aDataBuffer[4 * index] << 8) | aDataBuffer[4 * index + 1]));
    }
    if (BUFFER_SIZE % 4 == 3)
    {
      LL_CRC_FeedData16(CRC, (uint16_t)((aDataBuffer[4 * index] << 8) | aDataBuffer[4 * index + 1]));
      LL_CRC_FeedData8(CRC, aDataBuffer[4 * index + 2]);
    }
  }

  /* Return computed CRC value */
  return (LL_CRC_ReadData8(CRC));
}

/**
  * @brief  Check CRC computation result value.
  * @param  None
  * @retval None
  */
void CheckCRCResultValue(void)
{
  /* Compare the CRC value to the Expected one */
  if (ubCRCValue != ubExpectedCRCValue)
  {
    /* Wrong CRC value: Set LED2 to Blinking mode (Error) */
    LED_Blinking(LED_BLINK_ERROR);
  }
  else
  {
    /* Right CRC value: Turn LED2 on */
    LED_On();
  }
}

/**
  * @brief  Turn-on LED2.
  * @param  None
  * @retval None
  */
void LED_On(void)
{
  /* Turn LED2 on */
  LL_GPIO_SetOutputPin(LED2_GPIO_Port, LED2_Pin);
}

/**
  * @brief  Set LED2 to Blinking mode for an infinite loop (toggle period based on value provided as input parameter).
  * @param  Period : Period of time (in ms) between each toggling of LED
  *   This parameter can be user defined values. Pre-defined values used in that example are :
  *     @arg LED_BLINK_FAST : Fast Blinking
  *     @arg LED_BLINK_SLOW : Slow Blinking
  *     @arg LED_BLINK_ERROR : Error specific Blinking
  * @retval None
  */
void LED_Blinking(uint32_t Period)
{
  /* Toggle IO in an infinite loop */
  while (1)
  {
    LL_GPIO_TogglePin(LED2_GPIO_Port, LED2_Pin);
    LL_mDelay(Period);
  }
}




/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */

  /* USER CODE END Error_Handler_Debug */
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d", file, line) */

  /* Infinite loop */
  while (1)
  {
  }
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */