diff --git a/system/system_stm32f0xx.c b/system/system_stm32f0xx.c new file mode 100644 --- /dev/null +++ b/system/system_stm32f0xx.c @@ -0,0 +1,308 @@ +/** + ****************************************************************************** + * @file system_stm32f0xx.c + * @author MCD Application Team + * @version V2.1.0 + * @date 03-Oct-2014 + * @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 + * + *

© COPYRIGHT(c) 2014 STMicroelectronics

+ * + * 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 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)16000000) /*!< 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 */ +/** + * @} + */ + +/** @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; + +__IO const uint8_t AHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9}; + +/** + * @} + */ + +/** @addtogroup STM32F0xx_System_Private_FunctionPrototypes + * @{ + */ + +/** + * @} + */ + +/** @addtogroup STM32F0xx_System_Private_Functions + * @{ + */ + +/** + * @brief Setup the microcontroller system. + * Initialize the default HSI clock source, vector table location and the PLL configuration is reset. + * @param None + * @retval None + */ +void SystemInit(void) +{ + /* Reset the RCC clock configuration to the default reset state ------------*/ + /* Set HSION bit */ + RCC->CR |= (uint32_t)0x00000001; + +#if defined (STM32F051x8) || defined (STM32F058x8) + /* Reset SW[1:0], HPRE[3:0], PPRE[2:0], ADCPRE and MCOSEL[2:0] bits */ + RCC->CFGR &= (uint32_t)0xF8FFB80C; +#else + /* Reset SW[1:0], HPRE[3:0], PPRE[2:0], ADCPRE, MCOSEL[2:0], MCOPRE[2:0] and PLLNODIV bits */ + RCC->CFGR &= (uint32_t)0x08FFB80C; +#endif /* STM32F051x8 or STM32F058x8 */ + + /* Reset HSEON, CSSON and PLLON bits */ + RCC->CR &= (uint32_t)0xFEF6FFFF; + + /* Reset HSEBYP bit */ + RCC->CR &= (uint32_t)0xFFFBFFFF; + + /* Reset PLLSRC, PLLXTPRE and PLLMUL[3:0] bits */ + RCC->CFGR &= (uint32_t)0xFFC0FFFF; + + /* Reset PREDIV[3:0] bits */ + RCC->CFGR2 &= (uint32_t)0xFFFFFFF0; + +#if defined (STM32F071xB) || defined (STM32F072xB) || defined (STM32F078xB) + /* Reset USART2SW[1:0] USART1SW[1:0], I2C1SW, CECSW, USBSW and ADCSW bits */ + RCC->CFGR3 &= (uint32_t)0xFFFCFE2C; +#elif defined (STM32F091xC) || defined (STM32F098xx) + /* Reset USART3SW[1:0], USART2SW[1:0], USART1SW[1:0], I2C1SW, CECSW bits */ + RCC->CFGR3 &= (uint32_t)0xFFF0FFAC; +#else + /* Reset USART1SW[1:0], I2C1SW, CECSW, USBSW and ADCSW bits */ + RCC->CFGR3 &= (uint32_t)0xFFFFFE2C; +#endif + + /* Reset HSI14 bit */ + RCC->CR2 &= (uint32_t)0xFFFFFFFE; + + /* Disable all interrupts */ + RCC->CIR = 0x00000000; + +} + +/** + * @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(STM32F071xB) || defined(STM32F072xB) || defined(STM32F078xx) || defined(STM32F091xC) || defined(STM32F098xx) + /* 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 || STM32F071xB || STM32F072xB || STM32F078xx || STM32F091xC || STM32F098xx */ + } + 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****/