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Diffstat (limited to 'center_fw/system.c')
| -rw-r--r-- | center_fw/system.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/center_fw/system.c b/center_fw/system.c new file mode 100644 index 0000000..d4ca437 --- /dev/null +++ b/center_fw/system.c @@ -0,0 +1,302 @@ +/** + ****************************************************************************** + * @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; +} + + +/** + * @} + */ + +/** + * @} + */ + +/** + * @} + */ |