| /** |
| ****************************************************************************** |
| * @file system_stm32g0xx.c |
| * @author MCD Application Team |
| * @brief CMSIS Cortex-M0+ 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_stm32g0xx.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. |
| * |
| * After each device reset the HSI (8 MHz then 16 MHz) is used as system clock source. |
| * Then SystemInit() function is called, in "startup_stm32g0xx.s" file, to |
| * configure the system clock before to branch to main program. |
| * |
| * This file configures the system clock as follows: |
| *============================================================================= |
| *----------------------------------------------------------------------------- |
| * System Clock source | HSI |
| *----------------------------------------------------------------------------- |
| * SYSCLK(Hz) | 16000000 |
| *----------------------------------------------------------------------------- |
| * HCLK(Hz) | 16000000 |
| *----------------------------------------------------------------------------- |
| * AHB Prescaler | 1 |
| *----------------------------------------------------------------------------- |
| * APB Prescaler | 1 |
| *----------------------------------------------------------------------------- |
| * HSI Division factor | 1 |
| *----------------------------------------------------------------------------- |
| * PLL_M | 1 |
| *----------------------------------------------------------------------------- |
| * PLL_N | 8 |
| *----------------------------------------------------------------------------- |
| * PLL_P | 7 |
| *----------------------------------------------------------------------------- |
| * PLL_Q | 2 |
| *----------------------------------------------------------------------------- |
| * PLL_R | 2 |
| *----------------------------------------------------------------------------- |
| * Require 48MHz for RNG | Disabled |
| *----------------------------------------------------------------------------- |
| *============================================================================= |
| ****************************************************************************** |
| * @attention |
| * |
| * Copyright (c) 2018-2021 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. |
| * |
| ****************************************************************************** |
| */ |
| /** @addtogroup CMSIS |
| * @{ |
| */ |
| |
| /** @addtogroup stm32g0xx_system |
| * @{ |
| */ |
| |
| /** @addtogroup STM32G0xx_System_Private_Includes |
| * @{ |
| */ |
| |
| #include "stm32g0xx.h" |
| |
| #if !defined (HSE_VALUE) |
| #define HSE_VALUE (8000000UL) /*!< Value of the External oscillator in Hz */ |
| #endif /* HSE_VALUE */ |
| |
| #if !defined (HSI_VALUE) |
| #define HSI_VALUE (16000000UL) /*!< Value of the Internal oscillator in Hz*/ |
| #endif /* HSI_VALUE */ |
| |
| #if !defined (LSI_VALUE) |
| #define LSI_VALUE (32000UL) /*!< Value of LSI in Hz*/ |
| #endif /* LSI_VALUE */ |
| |
| #if !defined (LSE_VALUE) |
| #define LSE_VALUE (32768UL) /*!< Value of LSE in Hz*/ |
| #endif /* LSE_VALUE */ |
| |
| /** |
| * @} |
| */ |
| |
| /** @addtogroup STM32G0xx_System_Private_TypesDefinitions |
| * @{ |
| */ |
| |
| /** |
| * @} |
| */ |
| |
| /** @addtogroup STM32G0xx_System_Private_Defines |
| * @{ |
| */ |
| |
| /************************* Miscellaneous Configuration ************************/ |
| /* Note: Following vector table addresses must be defined in line with linker |
| configuration. */ |
| /*!< Uncomment the following line if you need to relocate the vector table |
| anywhere in Flash or Sram, else the vector table is kept at the automatic |
| remap of boot address selected */ |
| /* #define USER_VECT_TAB_ADDRESS */ |
| |
| #if defined(USER_VECT_TAB_ADDRESS) |
| /*!< Uncomment the following line if you need to relocate your vector Table |
| in Sram else user remap will be done in Flash. */ |
| /* #define VECT_TAB_SRAM */ |
| #if defined(VECT_TAB_SRAM) |
| #define VECT_TAB_BASE_ADDRESS SRAM_BASE /*!< Vector Table base address field. |
| This value must be a multiple of 0x200. */ |
| #define VECT_TAB_OFFSET 0x00000000U /*!< Vector Table base offset field. |
| This value must be a multiple of 0x200. */ |
| #else |
| #define VECT_TAB_BASE_ADDRESS FLASH_BASE /*!< Vector Table base address field. |
| This value must be a multiple of 0x200. */ |
| #define VECT_TAB_OFFSET 0x00000000U /*!< Vector Table base offset field. |
| This value must be a multiple of 0x200. */ |
| #endif /* VECT_TAB_SRAM */ |
| #endif /* USER_VECT_TAB_ADDRESS */ |
| /******************************************************************************/ |
| /** |
| * @} |
| */ |
| |
| /** @addtogroup STM32G0xx_System_Private_Macros |
| * @{ |
| */ |
| |
| /** |
| * @} |
| */ |
| |
| /** @addtogroup STM32G0xx_System_Private_Variables |
| * @{ |
| */ |
| /* The SystemCoreClock 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 = 16000000UL; |
| |
| const uint32_t AHBPrescTable[16UL] = {0UL, 0UL, 0UL, 0UL, 0UL, 0UL, 0UL, 0UL, 1UL, 2UL, 3UL, 4UL, 6UL, 7UL, 8UL, 9UL}; |
| const uint32_t APBPrescTable[8UL] = {0UL, 0UL, 0UL, 0UL, 1UL, 2UL, 3UL, 4UL}; |
| |
| /** |
| * @} |
| */ |
| |
| /** @addtogroup STM32G0xx_System_Private_FunctionPrototypes |
| * @{ |
| */ |
| |
| /** |
| * @} |
| */ |
| |
| /** @addtogroup STM32G0xx_System_Private_Functions |
| * @{ |
| */ |
| |
| /** |
| * @brief Setup the microcontroller system. |
| * @param None |
| * @retval None |
| */ |
| void SystemInit(void) |
| { |
| /* Configure the Vector Table location -------------------------------------*/ |
| #if defined(USER_VECT_TAB_ADDRESS) |
| SCB->VTOR = VECT_TAB_BASE_ADDRESS | VECT_TAB_OFFSET; /* Vector Table Relocation */ |
| #endif /* USER_VECT_TAB_ADDRESS */ |
| } |
| |
| /** |
| * @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(**) / HSI division factor |
| * |
| * - If SYSCLK source is HSE, SystemCoreClock will contain the HSE_VALUE(***) |
| * |
| * - If SYSCLK source is LSI, SystemCoreClock will contain the LSI_VALUE |
| * |
| * - If SYSCLK source is LSE, SystemCoreClock will contain the LSE_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 stm32g0xx_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 stm32g0xx_hal_conf.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; |
| uint32_t pllvco; |
| uint32_t pllr; |
| uint32_t pllsource; |
| uint32_t pllm; |
| uint32_t hsidiv; |
| |
| /* Get SYSCLK source -------------------------------------------------------*/ |
| switch (RCC->CFGR & RCC_CFGR_SWS) |
| { |
| case RCC_CFGR_SWS_0: /* HSE used as system clock */ |
| SystemCoreClock = HSE_VALUE; |
| break; |
| |
| case (RCC_CFGR_SWS_1 | RCC_CFGR_SWS_0): /* LSI used as system clock */ |
| SystemCoreClock = LSI_VALUE; |
| break; |
| |
| case RCC_CFGR_SWS_2: /* LSE used as system clock */ |
| SystemCoreClock = LSE_VALUE; |
| break; |
| |
| case RCC_CFGR_SWS_1: /* PLL used as system clock */ |
| /* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLLM) * PLLN |
| SYSCLK = PLL_VCO / PLLR |
| */ |
| pllsource = (RCC->PLLCFGR & RCC_PLLCFGR_PLLSRC); |
| pllm = ((RCC->PLLCFGR & RCC_PLLCFGR_PLLM) >> RCC_PLLCFGR_PLLM_Pos) + 1UL; |
| |
| if(pllsource == 0x03UL) /* HSE used as PLL clock source */ |
| { |
| pllvco = (HSE_VALUE / pllm); |
| } |
| else /* HSI used as PLL clock source */ |
| { |
| pllvco = (HSI_VALUE / pllm); |
| } |
| pllvco = pllvco * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> RCC_PLLCFGR_PLLN_Pos); |
| pllr = (((RCC->PLLCFGR & RCC_PLLCFGR_PLLR) >> RCC_PLLCFGR_PLLR_Pos) + 1UL); |
| |
| SystemCoreClock = pllvco/pllr; |
| break; |
| |
| case 0x00000000U: /* HSI used as system clock */ |
| default: /* HSI used as system clock */ |
| hsidiv = (1UL << ((READ_BIT(RCC->CR, RCC_CR_HSIDIV))>> RCC_CR_HSIDIV_Pos)); |
| SystemCoreClock = (HSI_VALUE/hsidiv); |
| break; |
| } |
| /* Compute HCLK clock frequency --------------------------------------------*/ |
| /* Get HCLK prescaler */ |
| tmp = AHBPrescTable[((RCC->CFGR & RCC_CFGR_HPRE) >> RCC_CFGR_HPRE_Pos)]; |
| /* HCLK clock frequency */ |
| SystemCoreClock >>= tmp; |
| } |
| |
| |
| /** |
| * @} |
| */ |
| |
| /** |
| * @} |
| */ |
| |
| /** |
| * @} |
| */ |
