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Diffstat (limited to 'cdc-dials/Src/system_stm32f0xx.c')
| -rw-r--r-- | cdc-dials/Src/system_stm32f0xx.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/cdc-dials/Src/system_stm32f0xx.c b/cdc-dials/Src/system_stm32f0xx.c new file mode 100644 index 0000000..6a3202b --- /dev/null +++ b/cdc-dials/Src/system_stm32f0xx.c @@ -0,0 +1,265 @@ +/**
+ ******************************************************************************
+ * @file system_stm32f0xx.c
+ * @author MCD Application Team
+ * @brief CMSIS Cortex-M0 Device Peripheral Access Layer System Source File.
+ *
+ * 1. 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_stm32f0xx.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_stm32f0xx.s" file, to
+ * configure the system clock before to branch to main program.
+ *
+ * 3. This file configures the system clock as follows:
+ *=============================================================================
+ * Supported STM32F0xx device
+ *-----------------------------------------------------------------------------
+ * System Clock source | HSI
+ *-----------------------------------------------------------------------------
+ * SYSCLK(Hz) | 8000000
+ *-----------------------------------------------------------------------------
+ * HCLK(Hz) | 8000000
+ *-----------------------------------------------------------------------------
+ * AHB Prescaler | 1
+ *-----------------------------------------------------------------------------
+ * APB1 Prescaler | 1
+ *-----------------------------------------------------------------------------
+ *=============================================================================
+ ******************************************************************************
+ * @attention
+ *
+ * <h2><center>© Copyright (c) 2016 STMicroelectronics.
+ * All rights reserved.</center></h2>
+ *
+ * This software component is licensed by ST under BSD 3-Clause license,
+ * the "License"; You may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at:
+ * opensource.org/licenses/BSD-3-Clause
+ *
+ ******************************************************************************
+ */
+
+/** @addtogroup CMSIS
+ * @{
+ */
+
+/** @addtogroup stm32f0xx_system
+ * @{
+ */
+
+/** @addtogroup STM32F0xx_System_Private_Includes
+ * @{
+ */
+
+#include "stm32f0xx.h"
+
+/**
+ * @}
+ */
+
+/** @addtogroup STM32F0xx_System_Private_TypesDefinitions
+ * @{
+ */
+
+/**
+ * @}
+ */
+
+/** @addtogroup STM32F0xx_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 */
+
+#if !defined (HSI48_VALUE)
+#define HSI48_VALUE ((uint32_t)48000000) /*!< Default value of the HSI48 Internal oscillator in Hz.
+ This value can be provided and adapted by the user application. */
+#endif /* HSI48_VALUE */
+/**
+ * @}
+ */
+
+/** @addtogroup STM32F0xx_System_Private_Macros
+ * @{
+ */
+
+/**
+ * @}
+ */
+
+/** @addtogroup STM32F0xx_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 there is no need to
+ call the 2 first functions listed above, since SystemCoreClock variable is
+ updated automatically.
+ */
+uint32_t SystemCoreClock = 8000000;
+
+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 STM32F0xx_System_Private_FunctionPrototypes
+ * @{
+ */
+
+/**
+ * @}
+ */
+
+/** @addtogroup STM32F0xx_System_Private_Functions
+ * @{
+ */
+
+/**
+ * @brief Setup the microcontroller system.
+ * @param None
+ * @retval None
+ */
+void SystemInit(void)
+{
+ /* NOTE :SystemInit(): This function is called at startup just after reset and
+ before branch to main program. This call is made inside
+ the "startup_stm32f0xx.s" file.
+ User can setups the default system clock (System clock source, PLL Multiplier
+ and Divider factors, AHB/APBx prescalers and Flash settings).
+ */
+}
+
+/**
+ * @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 stm32f0xx_hal.h file (default value
+ * 8 MHz) but the real value may vary depending on the variations
+ * in voltage and temperature.
+ *
+ * (**) HSE_VALUE is a constant defined in stm32f0xx_hal.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 = 0, pllmull = 0, pllsource = 0, predivfactor = 0;
+
+ /* Get SYSCLK source -------------------------------------------------------*/
+ tmp = RCC->CFGR & RCC_CFGR_SWS;
+
+ switch (tmp)
+ {
+ case RCC_CFGR_SWS_HSI: /* HSI used as system clock */
+ SystemCoreClock = HSI_VALUE;
+ break;
+ case RCC_CFGR_SWS_HSE: /* HSE used as system clock */
+ SystemCoreClock = HSE_VALUE;
+ break;
+ case RCC_CFGR_SWS_PLL: /* PLL used as system clock */
+ /* Get PLL clock source and multiplication factor ----------------------*/
+ pllmull = RCC->CFGR & RCC_CFGR_PLLMUL;
+ pllsource = RCC->CFGR & RCC_CFGR_PLLSRC;
+ pllmull = ( pllmull >> 18) + 2;
+ predivfactor = (RCC->CFGR2 & RCC_CFGR2_PREDIV) + 1;
+
+ if (pllsource == RCC_CFGR_PLLSRC_HSE_PREDIV)
+ {
+ /* HSE used as PLL clock source : SystemCoreClock = HSE/PREDIV * PLLMUL */
+ SystemCoreClock = (HSE_VALUE/predivfactor) * pllmull;
+ }
+#if defined(STM32F042x6) || defined(STM32F048xx) || defined(STM32F072xB) || defined(STM32F078xx) || defined(STM32F091xC) || defined(STM32F098xx)
+ else if (pllsource == RCC_CFGR_PLLSRC_HSI48_PREDIV)
+ {
+ /* HSI48 used as PLL clock source : SystemCoreClock = HSI48/PREDIV * PLLMUL */
+ SystemCoreClock = (HSI48_VALUE/predivfactor) * pllmull;
+ }
+#endif /* STM32F042x6 || STM32F048xx || STM32F072xB || STM32F078xx || STM32F091xC || STM32F098xx */
+ else
+ {
+#if defined(STM32F042x6) || defined(STM32F048xx) || defined(STM32F070x6) \
+ || defined(STM32F078xx) || defined(STM32F071xB) || defined(STM32F072xB) \
+ || defined(STM32F070xB) || defined(STM32F091xC) || defined(STM32F098xx) || defined(STM32F030xC)
+ /* HSI used as PLL clock source : SystemCoreClock = HSI/PREDIV * PLLMUL */
+ SystemCoreClock = (HSI_VALUE/predivfactor) * pllmull;
+#else
+ /* HSI used as PLL clock source : SystemCoreClock = HSI/2 * PLLMUL */
+ SystemCoreClock = (HSI_VALUE >> 1) * pllmull;
+#endif /* STM32F042x6 || STM32F048xx || STM32F070x6 ||
+ STM32F071xB || STM32F072xB || STM32F078xx || STM32F070xB ||
+ STM32F091xC || STM32F098xx || STM32F030xC */
+ }
+ break;
+ default: /* HSI used as system clock */
+ SystemCoreClock = HSI_VALUE;
+ break;
+ }
+ /* Compute HCLK clock frequency ----------------*/
+ /* Get HCLK prescaler */
+ tmp = AHBPrescTable[((RCC->CFGR & RCC_CFGR_HPRE) >> 4)];
+ /* HCLK clock frequency */
+ SystemCoreClock >>= tmp;
+}
+
+/**
+ * @}
+ */
+
+/**
+ * @}
+ */
+
+/**
+ * @}
+ */
+
+/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
+
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