text: /**
    ******************************************************************************
    * @file    Examples_LL/RCC/RCC_OutputSystemClockOnMCO/Src/main.c
    * @author  MCD Application Team
    * @brief   This example describes how to how to configure MCO pin to output 
    *          the system clock through the STM32F7xx RCC LL API.
    ******************************************************************************
    * @attention
    *
    * <h2><center>&copy; COPYRIGHT(c) 2016 STMicroelectronics</center></h2>
    *
    * Redistribution and use in source and binary forms, with or without modification,
    * are permitted provided that the following conditions are met:
    *   1. Redistributions of source code must retain the above copyright notice,
    *      this list of conditions and the following disclaimer.
    *   2. 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.
    *   3. Neither the name of STMicroelectronics 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 HOLDER 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.
    *
    ******************************************************************************
    */
  
  /* Includes ------------------------------------------------------------------*/
  #include "main.h"
  
  /** @addtogroup STM32F7xx_LL_Examples
    * @{
    */
  
  /** @addtogroup RCC_OutputSystemClockOnMCO
    * @{
    */
  
  /* Private typedef -----------------------------------------------------------*/
  /* Structure based on parameters used for MCO config */
  typedef struct
  {
    uint32_t Source;          /*!< Source of the MCO output */
    uint32_t Prescaler;       /*!< Prescaler applied to MCO output */
  } RCC_MCO_ConfigTypeDef;
  
  /* Private define ------------------------------------------------------------*/
  /* Number of MCO Config */
  #define RCC_MCO_CONFIG_NB   4
  
  /* Private macro -------------------------------------------------------------*/
  /* Private variables ---------------------------------------------------------*/
  /* Variable to set different MCO config */
  static RCC_MCO_ConfigTypeDef aMCO_Config[RCC_MCO_CONFIG_NB] = {
    {LL_RCC_MCO1SOURCE_HSI, LL_RCC_MCO1_DIV_1},
    {LL_RCC_MCO1SOURCE_PLLCLK, LL_RCC_MCO1_DIV_4},
    {LL_RCC_MCO2SOURCE_SYSCLK, LL_RCC_MCO2_DIV_2},
    {LL_RCC_MCO2SOURCE_HSE, LL_RCC_MCO2_DIV_2}
    };
  
  /* MCO Config index */
  __IO uint8_t bMCOIndex = 0;
  
  /* Private function prototypes -----------------------------------------------*/
  void SystemClock_Config(void);
  void MCO_ConfigGPIO(void);
  void LED_Init(void);
  void UserButton_Init(void);
  static void CPU_CACHE_Enable(void);
  /* Private functions ---------------------------------------------------------*/
  
  /**
    * @brief  Main program
    * @param  None
    * @retval None
    */
  int main(void)
  {
    /* Enable the CPU Cache */
    CPU_CACHE_Enable();
  
    /* Configure the system clock to 216 MHz */
    SystemClock_Config();
  
    /* Initialize LED1 */
    LED_Init();
  
    /* Initialize button in EXTI mode */
    UserButton_Init();
  
    /* Configure GPIO for MCO */
    MCO_ConfigGPIO();
  
    /* Infinite loop */
    while (1)
    {
      /* All the process are managed in UserButton_Callback function */
      /* Each time, user press user-button, a new MCO config is set */
    }
  }
  
  /**
    * @brief  Configure MCO pin (PA8 and PC9).
    * @param  None
    * @retval None
    */
  void MCO_ConfigGPIO(void)
  {
    /* MCO1 Clock Enable */
    LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOA);
  
    /* Configure the MCO1 pin in alternate function mode */
    LL_GPIO_SetPinMode(GPIOA, LL_GPIO_PIN_8, LL_GPIO_MODE_ALTERNATE);
    LL_GPIO_SetPinOutputType(GPIOA, LL_GPIO_PIN_8, LL_GPIO_OUTPUT_PUSHPULL);
    LL_GPIO_SetPinSpeed(GPIOA, LL_GPIO_PIN_8, LL_GPIO_SPEED_FREQ_HIGH);
    LL_GPIO_SetPinPull(GPIOA, LL_GPIO_PIN_8, LL_GPIO_PULL_NO);
    LL_GPIO_SetAFPin_8_15(GPIOA, LL_GPIO_PIN_8, LL_GPIO_AF_0);
  
    /* MCO2 Clock Enable */
    LL_AHB1_GRP1_EnableClock(LL_AHB1_GRP1_PERIPH_GPIOC);
  
    /* Configure the MCO2 pin in alternate function mode */
    LL_GPIO_SetPinMode(GPIOC, LL_GPIO_PIN_9, LL_GPIO_MODE_ALTERNATE);
    LL_GPIO_SetPinOutputType(GPIOC, LL_GPIO_PIN_9, LL_GPIO_OUTPUT_PUSHPULL);
    LL_GPIO_SetPinSpeed(GPIOC, LL_GPIO_PIN_9, LL_GPIO_SPEED_FREQ_HIGH);
    LL_GPIO_SetPinPull(GPIOC, LL_GPIO_PIN_9, LL_GPIO_PULL_NO);
    LL_GPIO_SetAFPin_8_15(GPIOC, LL_GPIO_PIN_9, LL_GPIO_AF_0);
  }
  
  /**
    * @brief  Initialize LED1.
    * @param  None
    * @retval None
    */
  void LED_Init(void)
  {
    /* Enable the LED1 Clock */
    LED1_GPIO_CLK_ENABLE();
  
    /* Configure IO in output push-pull mode to drive external LED1 */
    LL_GPIO_SetPinMode(LED1_GPIO_PORT, LED1_PIN, LL_GPIO_MODE_OUTPUT);
  }
  
  /**
    * @brief  Configures User push-button in GPIO or EXTI Line Mode.
    * @param  None
    * @retval None
    */
  void UserButton_Init(void)
  {
    /* Enable the BUTTON Clock */
    USER_BUTTON_GPIO_CLK_ENABLE();
  
    /* Configure GPIO for BUTTON */
    LL_GPIO_SetPinMode(USER_BUTTON_GPIO_PORT, USER_BUTTON_PIN, LL_GPIO_MODE_INPUT);
    LL_GPIO_SetPinPull(USER_BUTTON_GPIO_PORT, USER_BUTTON_PIN, LL_GPIO_PULL_NO);
  
    /* Connect External Line to the GPIO*/
    USER_BUTTON_SYSCFG_SET_EXTI();
  
    /* Enable a rising trigger EXTI line 13 Interrupt */
    USER_BUTTON_EXTI_LINE_ENABLE();
    USER_BUTTON_EXTI_FALLING_TRIG_ENABLE();
  
    /* Configure NVIC for USER_BUTTON_EXTI_IRQn */
    NVIC_EnableIRQ(USER_BUTTON_EXTI_IRQn); 
    NVIC_SetPriority(USER_BUTTON_EXTI_IRQn,0x03);
  }
  
  /**
    * @brief  System Clock Configuration
    *         The system Clock is configured as follow :
    *            System Clock source            = PLL (HSE)
    *            SYSCLK(Hz)                     = 216000000
    *            HCLK(Hz)                       = 216000000
    *            AHB Prescaler                  = 1
    *            APB1 Prescaler                 = 4
    *            APB2 Prescaler                 = 2
    *            HSI Frequency(Hz)              = 8000000
    *            PLL_M                          = 8
    *            PLL_N                          = 432
    *            PLL_P                          = 2
    *            VDD(V)                         = 3.3
    *            Main regulator output voltage  = Scale1 mode
    *            Flash Latency(WS)              = 7
    * @param  None
    * @retval None
    */
  void SystemClock_Config(void)
  {
    /* Enable HSE clock */
    LL_RCC_HSE_EnableBypass();
    LL_RCC_HSE_Enable();
    while(LL_RCC_HSE_IsReady() != 1)
    {
    };
  
    /* Set FLASH latency */
    LL_FLASH_SetLatency(LL_FLASH_LATENCY_7);
  
    /* Enable PWR clock */
    LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_PWR);
  
    /* Activation OverDrive Mode */
    LL_PWR_EnableOverDriveMode();
    while(LL_PWR_IsActiveFlag_OD() != 1)
    {
    };
  
    /* Activation OverDrive Switching */
    LL_PWR_EnableOverDriveSwitching();
    while(LL_PWR_IsActiveFlag_ODSW() != 1)
    {
    };
  
    /* Main PLL configuration and activation */
    LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSE, LL_RCC_PLLM_DIV_8, 432, LL_RCC_PLLP_DIV_2);
    LL_RCC_PLL_Enable();
    while(LL_RCC_PLL_IsReady() != 1)
    {
    };
  
    /* Sysclk activation on the main PLL */
    LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_1);
    LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_PLL);
    while(LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_PLL)
    {
    };
  
    /* Set APB1 & APB2 prescaler */
    LL_RCC_SetAPB1Prescaler(LL_RCC_APB1_DIV_4);
    LL_RCC_SetAPB2Prescaler(LL_RCC_APB2_DIV_2);
  
    /* Set systick to 1ms */
    SysTick_Config(216000000 / 1000);
  
    /* Update CMSIS variable (which can be updated also through SystemCoreClockUpdate function) */
    SystemCoreClock = 216000000;
  }
  
  /******************************************************************************/
  /*   USER IRQ HANDLER TREATMENT                                               */
  /******************************************************************************/
  /**
    * @brief  Function to manage User button press
    * @param  None
    * @retval None
    */
  void UserButton_Callback(void)
  {
    register uint32_t source = 0, prescaler = 0;
  
    /* Get the MCO config to apply */
    source = aMCO_Config[bMCOIndex].Source;
    prescaler = aMCO_Config[bMCOIndex].Prescaler;
  
    /* Toggle LED1 to indicate a button press */
    LL_GPIO_TogglePin(LED1_GPIO_PORT, LED1_PIN);
  
    /* Select MCO clock source and prescaler */
    LL_RCC_ConfigMCO(source, prescaler);
  
    /* Set new MCO config Index */
    bMCOIndex = (bMCOIndex + 1) % RCC_MCO_CONFIG_NB;
  }
  
  /**
    * @brief  CPU L1-Cache enable.
    * @param  None
    * @retval None
    */
  static void CPU_CACHE_Enable(void)
  {
    /* Enable I-Cache */
    SCB_EnableICache();
  
    /* Enable D-Cache */
    SCB_EnableDCache();
  }
  
  #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 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)
    {
    }
  }
  #endif
  
  /**
    * @}
    */
  
  /**
    * @}
    */
  
  /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
  