diff options
Diffstat (limited to 'src/uart-test/system_stm32f4xx.c')
| -rw-r--r-- | src/uart-test/system_stm32f4xx.c | 56 |
1 files changed, 28 insertions, 28 deletions
diff --git a/src/uart-test/system_stm32f4xx.c b/src/uart-test/system_stm32f4xx.c index 3068a90..35f79ba 100644 --- a/src/uart-test/system_stm32f4xx.c +++ b/src/uart-test/system_stm32f4xx.c @@ -6,16 +6,16 @@ * @date 26-February-2014 * @brief CMSIS Cortex-M4 Device Peripheral Access Layer System Source File. * - * This file provides two functions and one global variable to be called from + * 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 + * - 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 + * 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. @@ -57,8 +57,8 @@ /** @addtogroup stm32f4xx_system * @{ - */ - + */ + /** @addtogroup STM32F4xx_System_Private_Includes * @{ */ @@ -86,7 +86,7 @@ /*!< 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. +#define VECT_TAB_OFFSET 0x00 /*!< Vector Table base offset field. This value must be a multiple of 0x200. */ /******************************************************************************/ @@ -108,7 +108,7 @@ /* 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 + 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. @@ -134,7 +134,7 @@ /** * @brief Setup the microcontroller system - * Initialize the FPU setting, vector table location and External memory + * Initialize the FPU setting, vector table location and External memory * configuration. * @param None * @retval None @@ -177,41 +177,41 @@ void SystemInit(void) * 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 + * 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(**) + * + * - 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. - * + * 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; @@ -227,10 +227,10 @@ void SystemCoreClockUpdate(void) /* 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 */ @@ -263,8 +263,8 @@ void SystemCoreClockUpdate(void) /** * @} */ - + /** * @} - */ + */ /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/ |