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/**
******************************************************************************
* @file Examples_LL/RCC/RCC_UseHSI_PLLasSystemClock/Src/main.c
* @author MCD Application Team
* @brief This example describes how to change dynamically SYSCLK through
* the STM32F4xx RCC LL API.
******************************************************************************
* @attention
*
* Copyright (c) 2017 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.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/** @addtogroup STM32F4xx_LL_Examples
* @{
*/
/** @addtogroup RCC_UseHSI_PLLasSystemClock
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Structure based on parameters used for PLL config */
typedef struct
{
uint32_t Frequency; /*!< SYSCLK frequency requested */
uint32_t PLLM; /*!< PLLM factor used for PLL */
uint32_t PLLN; /*!< PLLN factor used for PLL */
uint32_t PLLP; /*!< PLLP factor used for PLL */
uint32_t Latency; /*!< Latency to be used with SYSCLK frequency */
} RCC_PLL_ConfigTypeDef;
/* Private define ------------------------------------------------------------*/
/* Number of PLL Config */
#define RCC_PLL_CONFIG_NB 2
#define RCC_FREQUENCY_LOW ((uint32_t)40000000) /* Low Frequency set to 40MHz*/
#define RCC_FREQUENCY_HIGH ((uint32_t)100000000) /* High Frequency set to 100MHz*/
/* Oscillator time-out values */
#define HSE_TIMEOUT_VALUE ((uint32_t)5000) /* Time out for HSE start up, in ms */
#define HSI_TIMEOUT_VALUE ((uint32_t)100) /* 100 ms */
#define PLL_TIMEOUT_VALUE ((uint32_t)100) /* 100 ms */
#define CLOCKSWITCH_TIMEOUT_VALUE ((uint32_t)5000) /* 5 s */
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Variable to set different PLL config with HSI as PLL source clock */
static RCC_PLL_ConfigTypeDef aPLL_ConfigHSI[RCC_PLL_CONFIG_NB] = {
{RCC_FREQUENCY_LOW, LL_RCC_PLLM_DIV_16, 80, LL_RCC_PLLP_DIV_2, LL_FLASH_LATENCY_1},
{RCC_FREQUENCY_HIGH, LL_RCC_PLLM_DIV_16, 200, LL_RCC_PLLP_DIV_2, LL_FLASH_LATENCY_3}
};
/* PLL Config index */
__IO uint8_t bPLLIndex = 0;
/* Variable to save the current configuration to apply */
static uint32_t uwFrequency = RCC_FREQUENCY_HIGH, uwPLLN = 0, uwPLLM = 0, uwPLLP = 0, uwLatency = 0;
/* Variable to indicate a change of PLL config after a button press */
__IO uint8_t bButtonPress = 0;
uint32_t Timeout = 0; /* Variable used for Timeout management */
/* Private macro -------------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
uint32_t RCC_StartHSIAndWaitForHSIReady(void);
uint32_t ChangePLL_HSI_Config(void);
void LED_Init(void);
void LED_Blinking(uint32_t Period);
void UserButton_Init(void);
uint32_t ChangePLLConfiguration(uint32_t PLLSource, uint32_t PLLM, uint32_t PLLN, uint32_t PLLP);
/* Private functions ---------------------------------------------------------*/
/**
* @brief Main program
* @param None
* @retval None
*/
int main(void)
{
/* Configure the system clock to 100 MHz */
SystemClock_Config();
/* Initialize LED2 */
LED_Init();
/* Initialize button in EXTI mode */
UserButton_Init();
/* Enable HSI to be able to select it as sysclk source */
/* Start HSI and wait for ready */
if (RCC_StartHSIAndWaitForHSIReady() != RCC_ERROR_NONE)
{
/* Problem to enable HSI, blink LED2 */
LED_Blinking(LED_BLINK_ERROR);
}
/* Infinite loop */
while (1)
{
/* Toggle LED accordingly to the frequency */
if (uwFrequency == RCC_FREQUENCY_LOW)
{
/* Slow toggle */
LED_Blinking(LED_BLINK_SLOW);
}
else
{
/* Fast toggle */
LED_Blinking(LED_BLINK_FAST);
}
/* PLL config change has been requested */
if (ChangePLL_HSI_Config() != RCC_ERROR_NONE)
{
/* Problem to switch to HSI, blink LED2 */
LED_Blinking(LED_BLINK_ERROR);
}
/* Reset button press */
bButtonPress = 0;
}
}
/**
* @brief Enable HSI and Wait for HSI ready
* @param None
* @retval RCC_ERROR_NONE if no error
*/
uint32_t RCC_StartHSIAndWaitForHSIReady()
{
/* Enable HSI and wait for HSI ready*/
LL_RCC_HSI_Enable();
#if (USE_TIMEOUT == 1)
Timeout = HSI_TIMEOUT_VALUE;
#endif /* USE_TIMEOUT */
while(LL_RCC_HSI_IsReady() != 1)
{
#if (USE_TIMEOUT == 1)
/* Check Systick counter flag to decrement the Time-out value */
if (LL_SYSTICK_IsActiveCounterFlag())
{
if(Timeout-- == 0)
{
/* Time-out occurred. Return an error */
return RCC_ERROR_TIMEOUT;
}
}
#endif /* USE_TIMEOUT */
};
return RCC_ERROR_NONE;
}
/**
* @brief Switch the PLL source to HSI, and select the PLL as SYSCLK
* source to reach new requested frequency.
* @param None
* @retval RCC_ERROR_NONE if no error
*/
uint32_t ChangePLL_HSI_Config(void)
{
/* Select HSI as system clock */
/* Wait for HSI switched */
LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_HSI);
#if (USE_TIMEOUT == 1)
Timeout = CLOCKSWITCH_TIMEOUT_VALUE;
#endif /* USE_TIMEOUT */
while (LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_HSI)
{
#if (USE_TIMEOUT == 1)
/* Check Systick counter flag to decrement the time-out value */
if (LL_SYSTICK_IsActiveCounterFlag())
{
if(Timeout-- == 0)
{
/* Time-out occurred. Return an error */
return RCC_ERROR_TIMEOUT;
}
}
#endif /* USE_TIMEOUT */
}
/* Configure PLL with new configuration */
if (ChangePLLConfiguration(LL_RCC_PLLSOURCE_HSI, uwPLLM, uwPLLN, uwPLLP) != RCC_ERROR_NONE)
{
return RCC_ERROR_TIMEOUT;
}
/* Latency must be managed differently if increase or decrease the frequency */
if (uwFrequency == RCC_FREQUENCY_LOW)
{
/* Decrease Frequency - latency should be set after setting PLL as clock source */
/* Select PLL as system clock */
/* Wait until the PLL is switched on */
LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_PLL);
#if (USE_TIMEOUT == 1)
Timeout = CLOCKSWITCH_TIMEOUT_VALUE;
#endif /* USE_TIMEOUT */
while (LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_PLL)
{
#if (USE_TIMEOUT == 1)
/* Check Systick counter flag to decrement the time-out value */
if (LL_SYSTICK_IsActiveCounterFlag())
{
if(Timeout-- == 0)
{
/* Time-out occurred. Return an error */
return RCC_ERROR_TIMEOUT;
}
}
#endif /* USE_TIMEOUT */
}
/* Set new latency */
LL_FLASH_SetLatency(uwLatency);
}
else
{
/* Increase Frequency - latency should be set before setting PLL as clock source */
/* Set new latency */
LL_FLASH_SetLatency(uwLatency);
/* Select PLL as system clock */
/* Wait until the PLL is switched on */
LL_RCC_SetSysClkSource(LL_RCC_SYS_CLKSOURCE_PLL);
#if (USE_TIMEOUT == 1)
Timeout = CLOCKSWITCH_TIMEOUT_VALUE;
#endif /* USE_TIMEOUT */
while (LL_RCC_GetSysClkSource() != LL_RCC_SYS_CLKSOURCE_STATUS_PLL)
{
#if (USE_TIMEOUT == 1)
/* Check Systick counter flag to decrement the time-out value */
if (LL_SYSTICK_IsActiveCounterFlag())
{
if(Timeout-- == 0)
{
/* Time-out occurred. Return an error */
return RCC_ERROR_TIMEOUT;
}
}
#endif /* USE_TIMEOUT */
}
}
/* Set systick to 1ms */
LL_Init1msTick(uwFrequency);
/* Update CMSIS variable (which can be updated also through SystemCoreClockUpdate function) */
SystemCoreClock = uwFrequency;
return RCC_ERROR_NONE;
}
/**
* @brief Function to change Main PLL configuration
* @param PLLSource: This parameter can be one of the following values:
* @arg LL_RCC_PLLSOURCE_HSI
* @arg LL_RCC_PLLSOURCE_HSE
* @param PLLM: This parameter can be one of the following values:
* @arg @ref LL_RCC_PLLM_DIV_2
* @arg @ref LL_RCC_PLLM_DIV_3
* @arg @ref LL_RCC_PLLM_DIV_4
* @arg @ref LL_RCC_PLLM_DIV_5
* @arg @ref LL_RCC_PLLM_DIV_6
* @arg @ref LL_RCC_PLLM_DIV_7
* @arg @ref LL_RCC_PLLM_DIV_8
* @arg @ref LL_RCC_PLLM_DIV_9
* @arg @ref LL_RCC_PLLM_DIV_10
* @arg @ref LL_RCC_PLLM_DIV_11
* @arg @ref LL_RCC_PLLM_DIV_12
* @arg @ref LL_RCC_PLLM_DIV_13
* @arg @ref LL_RCC_PLLM_DIV_14
* @arg @ref LL_RCC_PLLM_DIV_15
* @arg @ref LL_RCC_PLLM_DIV_16
* @arg @ref LL_RCC_PLLM_DIV_17
* @arg @ref LL_RCC_PLLM_DIV_18
* @arg @ref LL_RCC_PLLM_DIV_19
* @arg @ref LL_RCC_PLLM_DIV_20
* @arg @ref LL_RCC_PLLM_DIV_21
* @arg @ref LL_RCC_PLLM_DIV_22
* @arg @ref LL_RCC_PLLM_DIV_23
* @arg @ref LL_RCC_PLLM_DIV_24
* @arg @ref LL_RCC_PLLM_DIV_25
* @arg @ref LL_RCC_PLLM_DIV_26
* @arg @ref LL_RCC_PLLM_DIV_27
* @arg @ref LL_RCC_PLLM_DIV_28
* @arg @ref LL_RCC_PLLM_DIV_29
* @arg @ref LL_RCC_PLLM_DIV_30
* @arg @ref LL_RCC_PLLM_DIV_31
* @arg @ref LL_RCC_PLLM_DIV_32
* @arg @ref LL_RCC_PLLM_DIV_33
* @arg @ref LL_RCC_PLLM_DIV_34
* @arg @ref LL_RCC_PLLM_DIV_35
* @arg @ref LL_RCC_PLLM_DIV_36
* @arg @ref LL_RCC_PLLM_DIV_37
* @arg @ref LL_RCC_PLLM_DIV_38
* @arg @ref LL_RCC_PLLM_DIV_39
* @arg @ref LL_RCC_PLLM_DIV_40
* @arg @ref LL_RCC_PLLM_DIV_41
* @arg @ref LL_RCC_PLLM_DIV_42
* @arg @ref LL_RCC_PLLM_DIV_43
* @arg @ref LL_RCC_PLLM_DIV_44
* @arg @ref LL_RCC_PLLM_DIV_45
* @arg @ref LL_RCC_PLLM_DIV_46
* @arg @ref LL_RCC_PLLM_DIV_47
* @arg @ref LL_RCC_PLLM_DIV_48
* @arg @ref LL_RCC_PLLM_DIV_49
* @arg @ref LL_RCC_PLLM_DIV_50
* @arg @ref LL_RCC_PLLM_DIV_51
* @arg @ref LL_RCC_PLLM_DIV_52
* @arg @ref LL_RCC_PLLM_DIV_53
* @arg @ref LL_RCC_PLLM_DIV_54
* @arg @ref LL_RCC_PLLM_DIV_55
* @arg @ref LL_RCC_PLLM_DIV_56
* @arg @ref LL_RCC_PLLM_DIV_57
* @arg @ref LL_RCC_PLLM_DIV_58
* @arg @ref LL_RCC_PLLM_DIV_59
* @arg @ref LL_RCC_PLLM_DIV_60
* @arg @ref LL_RCC_PLLM_DIV_61
* @arg @ref LL_RCC_PLLM_DIV_62
* @arg @ref LL_RCC_PLLM_DIV_63
* @param PLLN: Between 50 and 432
* @param PLLP: This parameter can be one of the following values:
* @arg @ref LL_RCC_PLLP_DIV_2
* @arg @ref LL_RCC_PLLP_DIV_4
* @arg @ref LL_RCC_PLLP_DIV_6
* @arg @ref LL_RCC_PLLP_DIV_8
* @retval RCC_ERROR_NONE if no error
*/
uint32_t ChangePLLConfiguration(uint32_t PLLSource, uint32_t PLLM, uint32_t PLLN, uint32_t PLLP)
{
/* Disable the PLL */
/* Wait until PLLRDY is cleared */
LL_RCC_PLL_Disable();
#if (USE_TIMEOUT == 1)
Timeout = PLL_TIMEOUT_VALUE;
#endif /* USE_TIMEOUT */
while(LL_RCC_PLL_IsReady() != 0)
{
#if (USE_TIMEOUT == 1)
/* Check Systick counter flag to decrement the time-out value */
if (LL_SYSTICK_IsActiveCounterFlag())
{
if(Timeout-- == 0)
{
/* Time-out occurred. Return an error */
return RCC_ERROR_TIMEOUT;
}
}
#endif /* USE_TIMEOUT */
}
/* Configure PLL */
LL_RCC_PLL_ConfigDomain_SYS(PLLSource, PLLM, PLLN, PLLP);
/* Enable the PLL */
/* Wait until PLLRDY is set */
LL_RCC_PLL_Enable();
#if (USE_TIMEOUT == 1)
Timeout = PLL_TIMEOUT_VALUE;
#endif /* USE_TIMEOUT */
while(LL_RCC_PLL_IsReady() != 1)
{
#if (USE_TIMEOUT == 1)
/* Check Systick counter flag to decrement the time-out value */
if (LL_SYSTICK_IsActiveCounterFlag())
{
if(Timeout-- == 0)
{
/* Time-out occurred. Return an error */
return RCC_ERROR_TIMEOUT;
}
}
#endif /* USE_TIMEOUT */
}
return RCC_ERROR_NONE;
}
/**
* @brief Initialize LED2.
* @param None
* @retval None
*/
void LED_Init(void)
{
/* Enable the LED2 Clock */
LED2_GPIO_CLK_ENABLE();
/* Configure IO in output push-pull mode to drive external LED2 */
LL_GPIO_SetPinMode(LED2_GPIO_PORT, LED2_PIN, LL_GPIO_MODE_OUTPUT);
}
/**
* @brief Set LED2 to Blinking mode for an infinite loop (toggle period based on value provided as input parameter).
* Exit of this function when a press button is detected
* @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)
{
if (Period != LED_BLINK_ERROR)
{
/* Toggle IO in an infinite loop up to a detection of press button */
while (bButtonPress != 1)
{
/* LED2 is blinking at Period ms */
LL_GPIO_TogglePin(LED2_GPIO_PORT, LED2_PIN);
LL_mDelay(Period);
}
}
else
{
/* Toggle IO in an infinite loop due to an error */
while (1)
{
/* Error if LED2 is slowly blinking (1 sec. period) */
LL_GPIO_TogglePin(LED2_GPIO_PORT, LED2_PIN);
LL_mDelay(Period);
}
}
}
/**
* @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) = 100000000
* HCLK(Hz) = 100000000
* AHB Prescaler = 1
* APB1 Prescaler = 2
* APB2 Prescaler = 1
* HSE Frequency(Hz) = 8000000
* PLL_M = 8
* PLL_N = 400
* PLL_P = 4
* VDD(V) = 3.3
* Main regulator output voltage = Scale1 mode
* Flash Latency(WS) = 3
* @param None
* @retval None
*/
void SystemClock_Config(void)
{
/* Enable HSE oscillator */
LL_RCC_HSE_EnableBypass();
LL_RCC_HSE_Enable();
while(LL_RCC_HSE_IsReady() != 1)
{
};
/* Set FLASH latency */
LL_FLASH_SetLatency(LL_FLASH_LATENCY_3);
/* Main PLL configuration and activation */
LL_RCC_PLL_ConfigDomain_SYS(LL_RCC_PLLSOURCE_HSE, LL_RCC_PLLM_DIV_8, 400, LL_RCC_PLLP_DIV_4);
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_2);
LL_RCC_SetAPB2Prescaler(LL_RCC_APB2_DIV_1);
/* Set systick to 1ms */
SysTick_Config(100000000 / 1000);
/* Update CMSIS variable (which can be updated also through SystemCoreClockUpdate function) */
SystemCoreClock = 100000000;
}
/******************************************************************************/
/* USER IRQ HANDLER TREATMENT */
/******************************************************************************/
/**
* @brief Function to manage User button press
* @param None
* @retval None
*/
void UserButton_Callback(void)
{
/* Get the PLL config to apply */
uwFrequency = aPLL_ConfigHSI[bPLLIndex].Frequency;
uwPLLM = aPLL_ConfigHSI[bPLLIndex].PLLM;
uwPLLN = aPLL_ConfigHSI[bPLLIndex].PLLN;
uwPLLP = aPLL_ConfigHSI[bPLLIndex].PLLP;
uwLatency = aPLL_ConfigHSI[bPLLIndex].Latency;
/* Set new PLL config Index */
bPLLIndex = (bPLLIndex + 1) % RCC_PLL_CONFIG_NB;
/* Set variable to request of PLL config change */
bButtonPress = 1;
}
#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
/**
* @}
*/
/**
* @}
*/
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