/**
******************************************************************************
* @file system_stm32f1xx.c
* @author MCD Application Team
* @version V4.1.0
* @date 29-April-2016
* @brief CMSIS Cortex-M3 Device Peripheral Access Layer System Source File.
*
* 1. This file provides two functions and one global variable to be called from
* user application:
* - SystemInit(): Setups the system clock (System clock source, PLL Multiplier
* factors, AHB/APBx prescalers and Flash settings).
* This function is called at startup just after reset and
* before branch to main program. This call is made inside
* the "startup_stm32f1xx_xx.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_stm32f1xx_xx.s" file, to
* configure the system clock before to branch to main program.
*
* 4. The default value of HSE crystal is set to 8 MHz (or 25 MHz, depending on
* the product used), refer to "HSE_VALUE".
* When HSE is used as system clock source, directly or through PLL, and you
* are using different crystal you have to adapt the HSE value to your own
* configuration.
*
******************************************************************************
* @attention
*
* <h2><center>© 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.
*
******************************************************************************
*/
/** @addtogroup CMSIS
* @{
*/
/** @addtogroup stm32f1xx_system
* @{
*/
/** @addtogroup STM32F1xx_System_Private_Includes
* @{
*/
#include "stm32f1xx.h"
/**
* @}
*/
/** @addtogroup STM32F1xx_System_Private_TypesDefinitions
* @{
*/
/**
* @}
*/
/** @addtogroup STM32F1xx_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 */
/*!< Uncomment the following line if you need to use external SRAM */
#if defined(STM32F100xE) || defined(STM32F101xE) || defined(STM32F101xG) || defined(STM32F103xE) || defined(STM32F103xG)
/* #define DATA_IN_ExtSRAM */
#endif /* STM32F100xE || STM32F101xE || STM32F101xG || STM32F103xE || STM32F103xG */
/*!< Uncomment the following line if you need to relocate your vector Table in
Internal SRAM. */
/* #define VECT_TAB_SRAM */
#define VECT_TAB_OFFSET 0x0 /*!< Vector Table base offset field.
This value must be a multiple of 0x200. */
/**
* @}
*/
/** @addtogroup STM32F1xx_System_Private_Macros
* @{
*/
/**
* @}
*/
/** @addtogroup STM32F1xx_System_Private_Variables
* @{
*/
/*******************************************************************************
* Clock Definitions
*******************************************************************************/
#if defined(STM32F100xB) ||defined(STM32F100xE)
uint32_t SystemCoreClock = 24000000; /*!< System Clock Frequency (Core Clock) */
#else /*!< HSI Selected as System Clock source */
uint32_t SystemCoreClock = 72000000; /*!< System Clock Frequency (Core Clock) */
#endif
const uint8_t AHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9};
const uint8_t APBPrescTable[8] = {0, 0, 0, 0, 1, 2, 3, 4};
/**
* @}
*/
/** @addtogroup STM32F1xx_System_Private_FunctionPrototypes
* @{
*/
#if defined(STM32F100xE) || defined(STM32F101xE) || defined(STM32F101xG) || defined(STM32F103xE) || defined(STM32F103xG)
#ifdef DATA_IN_ExtSRAM
static void SystemInit_ExtMemCtl(void);
#endif /* DATA_IN_ExtSRAM */
#endif /* STM32F100xE || STM32F101xE || STM32F101xG || STM32F103xE || STM32F103xG */
/**
* @}
*/
/** @addtogroup STM32F1xx_System_Private_Functions
* @{
*/
/**
* @brief Setup the microcontroller system
* Initialize the Embedded Flash Interface, the PLL and update the
* SystemCoreClock variable.
* @note This function should be used only after reset.
* @param None
* @retval None
*/
void SystemInit (void)
{
/* Reset the RCC clock configuration to the default reset state(for debug purpose) */
/* Set HSION bit */
RCC->CR |= (uint32_t)0x00000001;
/* Reset SW, HPRE, PPRE1, PPRE2, ADCPRE and MCO bits */
#if !defined(STM32F105xC) && !defined(STM32F107xC)
RCC->CFGR &= (uint32_t)0xF8FF0000;
#else
RCC->CFGR &= (uint32_t)0xF0FF0000;
#endif /* STM32F105xC */
/* Reset HSEON, CSSON and PLLON bits */
RCC->CR &= (uint32_t)0xFEF6FFFF;
/* Reset HSEBYP bit */
RCC->CR &= (uint32_t)0xFFFBFFFF;
/* Reset PLLSRC, PLLXTPRE, PLLMUL and USBPRE/OTGFSPRE bits */
RCC->CFGR &= (uint32_t)0xFF80FFFF;
#if defined(STM32F105xC) || defined(STM32F107xC)
/* Reset PLL2ON and PLL3ON bits */
RCC->CR &= (uint32_t)0xEBFFFFFF;
/* Disable all interrupts and clear pending bits */
RCC->CIR = 0x00FF0000;
/* Reset CFGR2 register */
RCC->CFGR2 = 0x00000000;
#elif defined(STM32F100xB) || defined(STM32F100xE)
/* Disable all interrupts and clear pending bits */
RCC->CIR = 0x009F0000;
/* Reset CFGR2 register */
RCC->CFGR2 = 0x00000000;
#else
/* Disable all interrupts and clear pending bits */
RCC->CIR = 0