/**
******************************************************************************
* @file system_stm32f0xx.c
* @author MCD Application Team
* @version V2.2.0
* @date 05-December-2014
* @brief CMSIS Cortex-M0 Device Peripheral Access Layer System Source File.
*
* 1. This file provides two functions and one global variable to be called from
* user application:
* - SystemInit(): This function is called at startup just after reset and
* before branch to main program. This call is made inside
* the "startup_stm32f0xx.s" file.
*
* - SystemCoreClock variable: Contains the core clock (HCLK), it can be used
* by the user application to setup the SysTick
* timer or configure other parameters.
*
* - SystemCoreClockUpdate(): Updates the variable SystemCoreClock and must
* be called whenever the core clock is changed
* during program execution.
*
* 2. After each device reset the HSI (8 MHz) is used as system clock source.
* Then SystemInit() function is called, in "startup_stm32f0xx.s" file, to
* configure the system clock before to branch to main program.
*
* 3. This file configures the system clock as follows:
*=============================================================================
* System clock source | 1- PLL_HSE_EXTC | 3- PLL_HSI
* | (external 8 MHz clock) | (internal 48 MHz)
* | 2- PLL_HSE_XTAL |
* | (external 8 MHz xtal) |
*-----------------------------------------------------------------------------
* SYSCLK(MHz) | 48 | 48
*-----------------------------------------------------------------------------
* AHBCLK (MHz) | 48 | 48
*-----------------------------------------------------------------------------
* APB1CLK (MHz) | 48 | 48
*-----------------------------------------------------------------------------
* USB capable (48 MHz precise clock) | YES | YES
*=============================================================================
******************************************************************************
* @attention
*
*
© COPYRIGHT(c) 2014 STMicroelectronics
*
* 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.
*
******************************************************************************
*/
/** @addtogroup CMSIS
* @{
*/
/** @addtogroup stm32f0xx_system
* @{
*/
/** @addtogroup STM32F0xx_System_Private_Includes
* @{
*/
#include "stm32f0xx.h"
#include "hal_tick.h"
/**
* @}
*/
/** @addtogroup STM32F0xx_System_Private_TypesDefinitions
* @{
*/
/**
* @}
*/
/** @addtogroup STM32F0xx_System_Private_Defines
* @{
*/
#if !defined (HSE_VALUE)
#define HSE_VALUE ((uint32_t)8000000) /*!< Default value of the External oscillator in Hz.
This value can be provided and adapted by the user application. */
#endif /* HSE_VALUE */
#if !defined (HSI_VALUE)
#define HSI_VALUE ((uint32_t)8000000) /*!< Default value of the Internal oscillator in Hz.
This value can be provided and adapted by the user application. */
#endif /* HSI_VALUE */
/**
* @}
*/
/** @addtogroup STM32F0xx_System_Private_Macros
* @{
*/
/* Select the clock sources (other than HSI) to start with (0=OFF, 1=ON) */
#define USE_PLL_HSE_EXTC (1) /* Use external clock */
#define USE_PLL_HSE_XTAL (1) /* Use external xtal */
/**
* @}
*/
/** @addtogroup STM32F0xx_System_Private_Variables
* @{
*/
/* This variable is updated in three ways:
1) by calling CMSIS function SystemCoreClockUpdate()
2) by calling HAL API function HAL_RCC_GetHCLKFreq()
3) each time HAL_RCC_ClockConfig() is called to configure the system clock frequency
Note: If you use this function to configure the system clock there is no need to
call the 2 first functions listed above, since SystemCoreClock variable is
updated automatically.
*/
uint32_t SystemCoreClock = 48000000;
const uint8_t AHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9};
/**
* @}
*/
/** @addtogroup STM32F0xx_System_Private_FunctionPrototypes
* @{
*/
#if (USE_PLL_HSE_XTAL != 0) || (USE_PLL_HSE_EXTC != 0)
uint8_t SetSysClock_PLL_HSE(uint8_t bypass);
#endif
uint8_t SetSysClock_PLL_HSI(void);
/**
* @}
*/
/** @addtogroup STM32F0xx_System_Private_Functions
* @{
*/
extern int NVIC_vtor_remap;
/**
* @brief Setup the microcontroller system.
* Initialize the default HSI clock source, vector table location and the PLL configuration is reset.
* @param None
* @retval None
*/
void SystemInit(void)
{
/* Reset the RCC clock configuration to the default reset state ------------*/
/* Set HSION bit */
RCC->CR |= (uint32_t)0x00000001;
#if defined (STM32F051x8) || defined (STM32F058x8)
/* Reset SW[1:0], HPRE[3:0], PPRE[2:0], ADCPRE and MCOSEL[2:0] bits */
RCC->CFGR &= (uint32_t)0xF8FFB80C;
#else
/* Reset SW[1:0], HPRE[3:0], PPRE[2:0], ADCPRE, MCOSEL[2:0], MCOPRE[2:0] and PLLNODIV bits */
RCC->CFGR &= (uint32_t)0x08FFB80C;
#endif /* STM32F051x8 or STM32F058x8 */
/* Reset HSEON, CSSON and PLLON bits */
RCC->CR &= (uint32_t)0xFEF6FFFF;
/* Reset HSEBYP bit */
RCC->CR &= (uint32_t)0xFFFBFFFF;
/* Reset PLLSRC, PLLXTPRE and PLLMUL[3:0] bits */
RCC->CFGR &= (uint32_t)0xFFC0FFFF;
/* Reset PREDIV[3:0] bits */
RCC->CFGR2 &= (uint32_t)0xFFFFFFF0;
#if defined (STM32F072xB) || defined (STM32F078xB)
/* Reset USART2SW[1:0], USART1SW[1:0], I2C1SW, CECSW, USBSW and ADCSW bits */
RCC->CFGR3 &= (uint32_t)0xFFFCFE2C;
#elif defined (STM32F071xB)
/* Reset USART2SW[1:0], USART1SW[1:0], I2C1SW, CECSW and ADCSW bits */
RCC->CFGR3 &= (uint32_t)0xFFFFCEAC;
#elif defined (STM32F091xC) || defined (STM32F098xx)
/* Reset USART3SW[1:0], USART2SW[1:0], USART1SW[1:0], I2C1SW, CECSW and ADCSW bits */
RCC->CFGR3 &= (uint32_t)0xFFF0FEAC;
#elif defined (STM32F030x6) || defined (STM32F030x8) || defined (STM32F031x6) || defined (STM32F038xx) || defined (STM32F030xC)
/* Reset USART1SW[1:0], I2C1SW and ADCSW bits */
RCC->CFGR3 &= (uint32_t)0xFFFFFEEC;
#elif defined (STM32F051x8) || defined (STM32F058xx)
/* Reset USART1SW[1:0], I2C1SW, CECSW and ADCSW bits */
RCC->CFGR3 &= (uint32_t)0xFFFFFEAC;
#elif defined (STM32F042x6) || defined (STM32F048xx)
/* Reset USART1SW[1:0], I2C1SW, CECSW, USBSW and ADCSW bits */
RCC->CFGR3 &= (uint32_t)0xFFFFFE2C;
#elif defined (STM32F070x6) || defined (STM32F070xB)
/* Reset USART1SW[1:0], I2C1SW, USBSW and ADCSW bits */
RCC->CFGR3 &= (uint32_t)0xFFFFFE6C;
/* Set default USB clock to PLLCLK, since there is no HSI48 */
RCC->CFGR3 |= (uint32_t)0x00000080;
#else
#warning "No target selected"
#endif
/* Reset HSI14 bit */
RCC->CR2 &= (uint32_t)0xFFFFFFFE;
/* Disable all interrupts */
RCC->CIR = 0x00000000;
/* Configure the Cube driver */
SystemCoreClock = 8000000; // At this stage the HSI is used as system clock
NVIC_vtor_remap = 0; // Because it is not cleared the first time we enter in NVIC_SetVector()
HAL_Init();
/* Configure the System clock source, PLL Multiplier and Divider factors,
AHB/APBx prescalers and Flash settings */
SetSysClock();
/* Reset the timer to avoid issues after the RAM initialization */
TIM_MST_RESET_ON;
TIM_MST_RESET_OFF;
}
/**
* @brief Update SystemCoreClock variable according to Clock Register Values.
* The SystemCoreClock variable contains the core clock (HCLK), it can
* be used by the user application to setup the SysTick timer or configure
* other parameters.
*
* @note Each time the core clock (HCLK) changes, this function must be called
* to update SystemCoreClock variable value. Otherwise, any configuration
* based on this variable will be incorrect.
*
* @note - The system frequency computed by this function is not the real
* frequency in the chip. It is calculated based on the predefined
* constant and the selected clock source:
*
* - If SYSCLK source is HSI, SystemCoreClock will contain the HSI_VALUE(*)
*
* - If SYSCLK source is HSE, SystemCoreClock will contain the HSE_VALUE(**)
*
* - If SYSCLK source is PLL, SystemCoreClock will contain the HSE_VALUE(**)
* or HSI_VALUE(*) multiplied/divided by the PLL factors.
*
* (*) HSI_VALUE is a constant defined in stm32f0xx_hal.h file (default value
* 8 MHz) but the real value may vary depending on the variations
* in voltage and temperature.
*
* (**) HSE_VALUE is a constant defined in stm32f0xx_hal.h file (default value
* 8 MHz), user has to ensure that HSE_VALUE is same as the real
* frequency of the crystal used. Otherwise, this function may
* have wrong result.
*
* - The result of this function could be not correct when using fractional
* value for HSE crystal.
*
* @param None
* @retval None
*/
void SystemCoreClockUpdate (void)
{
uint32_t tmp = 0, pllmull = 0, pllsource = 0, predivfactor = 0;
/* Get SYSCLK source -------------------------------------------------------*/
tmp = RCC->CFGR & RCC_CFGR_SWS;
switch (tmp)
{
case RCC_CFGR_SWS_HSI: /* HSI used as system clock */
SystemCoreClock = HSI_VALUE;
break;
case RCC_CFGR_SWS_HSE: /* HSE used as system clock */
SystemCoreClock = HSE_VALUE;
break;
case RCC_CFGR_SWS_PLL: /* PLL used as system clock */
/* Get PLL clock source and multiplication factor ----------------------*/
pllmull = RCC->CFGR & RCC_CFGR_PLLMUL;
pllsource = RCC->CFGR & RCC_CFGR_PLLSRC;
pllmull = ( pllmull >> 18) + 2;
predivfactor = (RCC->CFGR2 & RCC_CFGR2_PREDIV) + 1;
if (pllsource == RCC_CFGR_PLLSRC_HSE_PREDIV)
{
/* HSE used as PLL clock source : SystemCoreClock = HSE/PREDIV * PLLMUL */
SystemCoreClock = (HSE_VALUE/predivfactor) * pllmull;
}
#if defined(STM32F042x6) || defined(STM32F048xx) || defined(STM32F072xB) || defined(STM32F078xx) || defined(STM32F091xC) || defined(STM32F098xx)
else if (pllsource == RCC_CFGR_PLLSRC_HSI48_PREDIV)
{
/* HSI48 used as PLL clock source : SystemCoreClock = HSI48/PREDIV * PLLMUL */
SystemCoreClock = (HSI48_VALUE/predivfactor) * pllmull;
}
#endif /* STM32F042x6 || STM32F048xx || STM32F072xB || STM32F078xx || STM32F091xC || STM32F098xx */
else
{
#if defined(STM32F042x6) || defined(STM32F048xx) || defined(STM32F070x6) || \
defined(STM32F078xx) || defined(STM32F071xB) || defined(STM32F072xB) || defined(STM32F070xB) || \
defined(STM32F091xC) || defined(STM32F098xx) || defined(STM32F030xC)
/* HSI used as PLL clock source : SystemCoreClock = HSI/PREDIV * PLLMUL */
SystemCoreClock = (HSI_VALUE/predivfactor) * pllmull;
#else
/* HSI used as PLL clock source : SystemCoreClock = HSI/2 * PLLMUL */
SystemCoreClock = (HSI_VALUE >> 1) * pllmull;
#endif /* STM32F042x6 || STM32F048xx || STM32F070x6 ||
STM32F071xB || STM32F072xB || STM32F078xx || STM32F070xB ||
STM32F091xC || STM32F098xx || STM32F030xC */
}
break;
default: /* HSI used as system clock */
SystemCoreClock = HSI_VALUE;
break;
}
/* Compute HCLK clock frequency ----------------*/
/* Get HCLK prescaler */
tmp = AHBPrescTable[((RCC->CFGR & RCC_CFGR_HPRE) >> 4)];
/* HCLK clock frequency */
SystemCoreClock >>= tmp;
}
/**
* @brief Configures the System clock source, PLL Multiplier and Divider factors,
* AHB/APBx prescalers and Flash settings
* @note This function should be called only once the RCC clock configuration
* is reset to the default reset state (done in SystemInit() function).
* @param None
* @retval None
*/
void SetSysClock(void)
{
/* 1- Try to start with HSE and external clock */
#if USE_PLL_HSE_EXTC != 0
if (SetSysClock_PLL_HSE(1) == 0)
#endif
{
/* 2- If fail try to start with HSE and external xtal */
#if USE_PLL_HSE_XTAL != 0
if (SetSysClock_PLL_HSE(0) == 0)
#endif
{
/* 3- If fail start with HSI clock */
if (SetSysClock_PLL_HSI() == 0)
{
while(1)
{
// [TODO] Put something here to tell the user that a problem occured...
}
}
}
}
// Output clock on MCO pin(PA8) for debugging purpose
//HAL_RCC_MCOConfig(RCC_MCO, RCC_MCOSOURCE_SYSCLK, RCC_MCO_NODIV); // 48 MHz
}
#if (USE_PLL_HSE_XTAL != 0) || (USE_PLL_HSE_EXTC != 0)
/******************************************************************************/
/* PLL (clocked by HSE) used as System clock source */
/******************************************************************************/
uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
{
RCC_ClkInitTypeDef RCC_ClkInitStruct;
RCC_OscInitTypeDef RCC_OscInitStruct;
// Select HSE oscillator as PLL source
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE | RCC_OSCILLATORTYPE_HSI48;
if (bypass == 0) {
RCC_OscInitStruct.HSEState = RCC_HSE_ON; // External 8 MHz xtal on OSC_IN/OSC_OUT
} else {
RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS; // External 8 MHz clock on OSC_IN only
}
RCC_OscInitStruct.HSI48State = 0; // not used
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV2;
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL12;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
return 0; // FAIL
}
// Select PLL as system clock source and configure the HCLK and PCLK1 clocks dividers
RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1);
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK; // 48 MHz
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1; // 48 MHz
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1; // 48 MHz
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK) {
return 0; // FAIL
}
// Output clock on MCO pin(PA8) for debugging purpose
//if (bypass == 0)
// HAL_RCC_MCOConfig(RCC_MCO, RCC_MCOSOURCE_HSE, RCC_MCO_DIV2); // 4 MHz with xtal
//else
// HAL_RCC_MCOConfig(RCC_MCO, RCC_MCOSOURCE_HSE, RCC_MCO_DIV4); // 2 MHz with ST-Link MCO
return 1; // OK
}
#endif
/******************************************************************************/
/* PLL (clocked by HSI) used as System clock source */
/******************************************************************************/
uint8_t SetSysClock_PLL_HSI(void)
{
RCC_ClkInitTypeDef RCC_ClkInitStruct;
RCC_OscInitTypeDef RCC_OscInitStruct;
// Select PLLCLK = 48 MHz ((HSI 8 MHz / 2) * 12)
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI; // HSI div 2
RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV1;
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL12;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK) {
return 0; // FAIL
}
// Select PLL as system clock source and configure the HCLK and PCLK1 clocks dividers
RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1);
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK; // 48 MHz
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1; // 48 MHz
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1; // 48 MHz
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK) {
return 0; // FAIL
}
// Output clock on MCO1 pin(PA8) for debugging purpose
//HAL_RCC_MCOConfig(RCC_MCO, RCC_MCOSOURCE_HSI48, RCC_MCO_DIV1); // 48 MHz
return 1; // OK
}
/**
* @}
*/
/**
* @}
*/
/**
* @}
*/
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/