| /** |
| ****************************************************************************** |
| * @file system_stm32f4xx.c |
| * @author MCD Application Team |
| * @version V1.2.4 |
| * @date 06-May-2016 |
| * @brief CMSIS Cortex-M4 Device Peripheral Access Layer System Source File. |
| * |
| * 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_stm32f4xx.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. |
| * |
| * |
| ****************************************************************************** |
| * @attention |
| * |
| * <h2><center>© COPYRIGHT 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 stm32f4xx_system |
| * @{ |
| */ |
| |
| /** @addtogroup STM32F4xx_System_Private_Includes |
| * @{ |
| */ |
| |
| #include "stm32f4xx.h" |
| #include "mcu/cmsis_nvic.h" |
| |
| #if !defined (HSE_VALUE) |
| #define HSE_VALUE ((uint32_t)8000000) /*!< Default value of the External oscillator in Hz */ |
| #endif /* HSE_VALUE */ |
| |
| #if !defined (HSI_VALUE) |
| #define HSI_VALUE ((uint32_t)16000000) /*!< Value of the Internal oscillator in Hz*/ |
| #endif /* HSI_VALUE */ |
| |
| /** |
| * @} |
| */ |
| |
| /** @addtogroup STM32F4xx_System_Private_TypesDefinitions |
| * @{ |
| */ |
| |
| /** |
| * @} |
| */ |
| |
| /** @addtogroup STM32F4xx_System_Private_Defines |
| * @{ |
| */ |
| |
| /************************* Miscellaneous Configuration ************************/ |
| |
| /*!< Uncomment the following line if you need to relocate your vector Table in |
| Internal SRAM. */ |
| /* #define VECT_TAB_SRAM */ |
| #define VECT_TAB_OFFSET 0x00 /*!< Vector Table base offset field. |
| This value must be a multiple of 0x200. */ |
| /******************************************************************************/ |
| |
| /** |
| * @} |
| */ |
| |
| /** @addtogroup STM32F4xx_System_Private_Macros |
| * @{ |
| */ |
| |
| /** |
| * @} |
| */ |
| |
| /** @addtogroup STM32F4xx_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; then there |
| is no need to call the 2 first functions listed above, since SystemCoreClock |
| variable is updated automatically. |
| */ |
| uint32_t SystemCoreClock = 16000000; |
| 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] = {0U, 0U, 0U, 0U, 1U, 2U, 3U, 4U}; |
| /** |
| * @} |
| */ |
| |
| /** @addtogroup STM32F4xx_System_Private_FunctionPrototypes |
| * @{ |
| */ |
| |
| /** |
| * @} |
| */ |
| |
| /** @addtogroup STM32F4xx_System_Private_Functions |
| * @{ |
| */ |
| |
| /** |
| * @brief Setup the microcontroller system |
| * Initialize the FPU setting, vector table location and External memory |
| * configuration. |
| * @param None |
| * @retval None |
| */ |
| void SystemInit(void) |
| { |
| /* FPU settings ------------------------------------------------------------*/ |
| #if (__FPU_PRESENT == 1) && (__FPU_USED == 1) |
| SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2)); /* set CP10 and CP11 Full Access */ |
| #endif |
| /* Reset the RCC clock configuration to the default reset state ------------*/ |
| /* Set HSION bit */ |
| RCC->CR |= (uint32_t)0x00000001; |
| |
| /* Reset CFGR register */ |
| RCC->CFGR = 0x00000000; |
| |
| /* Reset HSEON, CSSON and PLLON bits */ |
| RCC->CR &= (uint32_t)0xFEF6FFFF; |
| |
| /* Reset PLLCFGR register */ |
| RCC->PLLCFGR = 0x24003010; |
| |
| /* Reset HSEBYP bit */ |
| RCC->CR &= (uint32_t)0xFFFBFFFF; |
| |
| /* Disable all interrupts */ |
| RCC->CIR = 0x00000000; |
| |
| /* Relocate the vector table */ |
| NVIC_Relocate(); |
| } |
| |
| /** |
| * @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 stm32f4xx_hal_conf.h file (default value |
| * 16 MHz) but the real value may vary depending on the variations |
| * in voltage and temperature. |
| * |
| * (**) HSE_VALUE is a constant defined in stm32f4xx_hal_conf.h file (its value |
| * depends on the application requirements), 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, pllvco = 0, pllp = 2, pllsource = 0, pllm = 2; |
| |
| /* Get SYSCLK source -------------------------------------------------------*/ |
| tmp = RCC->CFGR & RCC_CFGR_SWS; |
| |
| switch (tmp) |
| { |
| case 0x00: /* HSI used as system clock source */ |
| SystemCoreClock = HSI_VALUE; |
| break; |
| case 0x04: /* HSE used as system clock source */ |
| SystemCoreClock = HSE_VALUE; |
| break; |
| case 0x08: /* PLL used as system clock source */ |
| |
| /* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLL_M) * PLL_N |
| SYSCLK = PLL_VCO / PLL_P |
| */ |
| pllsource = (RCC->PLLCFGR & RCC_PLLCFGR_PLLSRC) >> 22; |
| pllm = RCC->PLLCFGR & RCC_PLLCFGR_PLLM; |
| |
| if (pllsource != 0) |
| { |
| /* HSE used as PLL clock source */ |
| pllvco = (HSE_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6); |
| } |
| else |
| { |
| /* HSI used as PLL clock source */ |
| pllvco = (HSI_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6); |
| } |
| |
| pllp = (((RCC->PLLCFGR & RCC_PLLCFGR_PLLP) >>16) + 1 ) *2; |
| SystemCoreClock = pllvco/pllp; |
| break; |
| default: |
| SystemCoreClock = HSI_VALUE; |
| break; |
| } |
| /* Compute HCLK frequency --------------------------------------------------*/ |
| /* Get HCLK prescaler */ |
| tmp = AHBPrescTable[((RCC->CFGR & RCC_CFGR_HPRE) >> 4)]; |
| /* HCLK frequency */ |
| SystemCoreClock >>= tmp; |
| } |
| |
| /** |
| * @} |
| */ |
| |
| /** |
| * @} |
| */ |
| |
| /** |
| * @} |
| */ |
| /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/ |
