/**
******************************************************************************
* @file stm32l1xx_ll_rcc.c
* @author MCD Application Team
* @brief RCC LL module driver.
******************************************************************************
* @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.
******************************************************************************
*/
#if defined(USE_FULL_LL_DRIVER)
/* Includes ------------------------------------------------------------------*/
#include "stm32l1xx_ll_rcc.h"
/** @addtogroup STM32L1xx_LL_Driver
* @{
*/
#if defined(RCC)
/** @defgroup RCC_LL RCC
* @{
*/
/* Private types -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Private constants ---------------------------------------------------------*/
/* Private macros ------------------------------------------------------------*/
/* Private function prototypes -----------------------------------------------*/
/** @defgroup RCC_LL_Private_Functions RCC Private functions
* @{
*/
static uint32_t RCC_GetSystemClockFreq(void);
static uint32_t RCC_GetHCLKClockFreq(uint32_t SYSCLK_Frequency);
static uint32_t RCC_GetPCLK1ClockFreq(uint32_t HCLK_Frequency);
static uint32_t RCC_GetPCLK2ClockFreq(uint32_t HCLK_Frequency);
static uint32_t RCC_PLL_GetFreqDomain_SYS(void);
/**
* @}
*/
/* Exported functions --------------------------------------------------------*/
/** @addtogroup RCC_LL_Exported_Functions
* @{
*/
/** @addtogroup RCC_LL_EF_Init
* @{
*/
/**
* @brief Reset the RCC clock configuration to the default reset state.
* @note The default reset state of the clock configuration is given below:
* - MSI ON and used as system clock source
* - HSE, HSI and PLL OFF
* - AHB, APB1 and APB2 prescaler set to 1.
* - CSS, MCO OFF
* - All interrupts disabled
* @note This function doesn't modify the configuration of the
* - Peripheral clocks
* - LSI, LSE and RTC clocks
* @retval An ErrorStatus enumeration value:
* - SUCCESS: RCC registers are de-initialized
* - ERROR: not applicable
*/
ErrorStatus LL_RCC_DeInit(void)
{
__IO uint32_t vl_mask;
/* Set MSION bit */
LL_RCC_MSI_Enable();
/* Insure MSIRDY bit is set before writing default MSIRANGE value */
while (LL_RCC_MSI_IsReady() == 0U)
{
__NOP();
}
/* Set MSIRANGE default value */
LL_RCC_MSI_SetRange(LL_RCC_MSIRANGE_5);
/* Set MSITRIM bits to the reset value*/
LL_RCC_MSI_SetCalibTrimming(0U);
/* Set HSITRIM bits to the reset value*/
LL_RCC_HSI_SetCalibTrimming(0x10U);
/* Reset SW, HPRE, PPRE and MCOSEL bits */
vl_mask = 0xFFFFFFFFU;
CLEAR_BIT(vl_mask, (RCC_CFGR_SW | RCC_CFGR_HPRE | RCC_CFGR_PPRE1 | RCC_CFGR_PPRE2 | RCC_CFGR_MCOSEL));
LL_RCC_WriteReg(CFGR, vl_mask);
/* Read CR register */
vl_mask = LL_RCC_ReadReg(CR);
/* Reset HSION, HSEON, CSSON, PLLON bits */
CLEAR_BIT(vl_mask, (RCC_CR_PLLON | RCC_CR_CSSON | RCC_CR_HSEON | RCC_CR_HSION));
LL_RCC_WriteReg(CR, vl_mask);
/* Reset HSEBYP bit */
LL_RCC_HSE_DisableBypass();
/* Insure PLL is disabled before to reset PLLSRC/PLLMUL/PLLDIV in CFGR register */
while(LL_RCC_PLL_IsReady() != 0U) {};
/* Reset CFGR register */
LL_RCC_WriteReg(CFGR, 0x00000000U);
/* Disable all interrupts */
LL_RCC_WriteReg(CIR, 0x00000000U);
/* Clear pending flags */
#if defined(RCC_LSECSS_SUPPORT)
vl_mask = (LL_RCC_CIR_LSIRDYC | LL_RCC_CIR_LSERDYC | LL_RCC_CIR_HSIRDYC | LL_RCC_CIR_HSERDYC | \
LL_RCC_CIR_PLLRDYC | LL_RCC_CIR_MSIRDYC | LL_RCC_CIR_LSECSSC | LL_RCC_CIR_CSSC);
#else
vl_mask = (LL_RCC_CIR_LSIRDYC | LL_RCC_CIR_LSERDYC | LL_RCC_CIR_HSIRDYC | LL_RCC_CIR_HSERDYC | \
LL_RCC_CIR_PLLRDYC | LL_RCC_CIR_MSIRDYC | LL_RCC_CIR_CSSC);
#endif /* RCC_LSECSS_SUPPORT */
LL_RCC_WriteReg(CIR, vl_mask);
/* Clear reset flags */
LL_RCC_ClearResetFlags();
return SUCCESS;
}
/**
* @}
*/
/** @addtogroup RCC_LL_EF_Get_Freq
* @brief Return the frequencies of different on chip clocks; System, AHB, APB1 and APB2 buses clocks
* and different peripheral clocks available on the device.
* @note If SYSCLK source is MSI, function returns values based on MSI clock(*)
* @note If SYSCLK source is HSI, function returns values based on HSI_VALUE(**)
* @note If SYSCLK source is HSE, function returns values based on HSE_VALUE(***)
* @note If SYSCLK source is PLL, function returns values based on
* HSI_VALUE(**) or HSE_VALUE(***) multiplied/divided by the PLL factors.
* @note (*) MSI clock depends on the selected MSI range but the real value
* may vary depending on the variations in voltage and temperature.
* @note (**) HSI_VALUE is a defined constant but the real value may vary
* depending on the variations in voltage and temperature.
* @note (***) HSE_VALUE is a defined constant, user has to ensure that
* HSE_VALUE is same as the real frequency of the crystal used.
* Otherwise, this function may have wrong result.
* @note The result of this function could be incorrect when using fractional
* value for HSE crystal.
* @note This function can be used by the user application to compute the
* baud-rate for the communication peripherals or configure other parameters.
* @{
*/
/**
* @brief Return the frequencies of different on chip clocks; System, AHB, APB1 and APB2 buses clocks
* @note Each time SYSCLK, HCLK, PCLK1 and/or PCLK2 clock changes, this function
* must be called to update structure fields. Otherwise, any
* configuration based on this function will be incorrect.
* @param RCC_Clocks pointer to a @ref LL_RCC_ClocksTypeDef structure which will hold the clocks frequencies
* @retval None
*/
void LL_RCC_GetSystemClocksFreq(LL_RCC_ClocksTypeDef *RCC_Clocks)
{
/* Get SYSCLK frequency */
RCC_Clocks->SYSCLK_Frequency = RCC_GetSystemClockFreq();
/* HCLK clock frequency */
RCC_Clocks->HCLK_Frequency = RCC_GetHCLKClockFreq(RCC_Clocks->SYSCLK_Frequency);
/* PCLK1 clock frequency */
RCC_Clocks->PCLK1_Frequency = RCC_GetPCLK1ClockFreq(RCC_Clocks->HCLK_Frequency);
/* PCLK2 clock frequency */
RCC_Clocks->PCLK2_Frequency = RCC_GetPCLK2ClockFreq(RCC_Clocks->HCLK_Frequency);
}
/**
* @}
*/
/**
* @}
*/
/** @addtogroup RCC_LL_Private_Functions
* @{
*/
/**
* @brief Return SYSTEM clock frequency
* @retval SYSTEM clock frequency (in Hz)
*/
static uint32_t RCC_GetSystemClockFreq(void)
{
uint32_t frequency;
/* Get SYSCLK source -------------------------------------------------------*/
switch (LL_RCC_GetSysClkSource())
{
case LL_RCC_SYS_CLKSOURCE_STATUS_MSI: /* MSI used as system clock source */
frequency = __LL_RCC_CALC_MSI_FREQ(LL_RCC_MSI_GetRange());
break;
case LL_RCC_SYS_CLKSOURCE_STATUS_HSI: /* HSI used as system clock source */
frequency = HSI_VALUE;
break;
case LL_RCC_SYS_CLKSOURCE_STATUS_HSE: /* HSE used as system clock source */
frequency = HSE_VALUE;
break;
case LL_RCC_SYS_CLKSOURCE_STATUS_PLL: /* PLL used as system clock source */
frequency = RCC_PLL_GetFreqDomain_SYS();
break;
default:
frequency = __LL_RCC_CALC_MSI_FREQ(LL_RCC_MSI_GetRange());
break;
}
return frequency;
}
/**
* @brief Return HCLK clock frequency
* @param SYSCLK_Frequency SYSCLK clock frequency
* @retval HCLK clock frequency (in Hz)
*/
static uint32_t RCC_GetHCLKClockFreq(uint32_t SYSCLK_Frequency)
{
/* HCLK clock frequency */
return __LL_RCC_CALC_HCLK_FREQ(SYSCLK_Frequency, LL_RCC_GetAHBPrescaler());
}
/**
* @brief Return PCLK1 clock frequency
* @param HCLK_Frequency HCLK clock frequency
* @retval PCLK1 clock frequency (in Hz)
*/
static uint32_t RCC_GetPCLK1ClockFreq(uint32_t HCLK_Frequency)
{
/* PCLK1 clock frequency */
return __LL_RCC_CALC_PCLK1_FREQ(HCLK_Frequency, LL_RCC_GetAPB1Prescaler());
}
/**
* @brief Return PCLK2 clock frequency
* @param HCLK_Frequency HCLK clock frequency
* @retval PCLK2 clock frequency (in Hz)
*/
static uint32_t RCC_GetPCLK2ClockFreq(uint32_t HCLK_Frequency)
{
/* PCLK2 clock frequency */
return __LL_RCC_CALC_PCLK2_FREQ(HCLK_Frequency, LL_RCC_GetAPB2Prescaler());
}
/**
* @brief Return PLL clock frequency used for system domain
* @retval PLL clock frequency (in Hz)
*/
static uint32_t RCC_PLL_GetFreqDomain_SYS(void)
{
uint32_t pllsource, pllinputfreq;
/* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLL divider) * PLL Multiplicator */
/* Get PLL source */
pllsource = LL_RCC_PLL_GetMainSource();
switch (pllsource)
{
case LL_RCC_PLLSOURCE_HSI: /* HSI used as PLL clock source */
pllinputfreq = HSI_VALUE;
break;
case LL_RCC_PLLSOURCE_HSE: /* HSE used as PLL clock source */
pllinputfreq = HSE_VALUE;
break;
default:
pllinputfreq = HSI_VALUE;
break;
}
return __LL_RCC_CALC_PLLCLK_FREQ(pllinputfreq, LL_RCC_PLL_GetMultiplicator(), LL_RCC_PLL_GetDivider());
}
/**
* @}
*/
/**
* @}
*/
#endif /* defined(RCC) */
/**
* @}
*/
#endif /* USE_FULL_LL_DRIVER */