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Diffstat (limited to 'system.c')
| -rw-r--r-- | system.c | 427 |
1 files changed, 427 insertions, 0 deletions
diff --git a/system.c b/system.c new file mode 100644 index 0000000..81dfaf9 --- /dev/null +++ b/system.c @@ -0,0 +1,427 @@ +/** + ****************************************************************************** + * @file system_stm32f1xx.c + * @author MCD Application Team + * @brief CMSIS Cortex-M3 Device Peripheral Access Layer System Source File. + * + * 1. This file provides two functions and one global variable to be called from + * user application: + * - SystemInit(): Setups the system clock (System clock source, PLL Multiplier + * factors, AHB/APBx prescalers and Flash settings). + * This function is called at startup just after reset and + * before branch to main program. This call is made inside + * the "startup_stm32f1xx_xx.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_stm32f1xx_xx.s" file, to + * configure the system clock before to branch to main program. + * + * 4. The default value of HSE crystal is set to 8 MHz (or 25 MHz, depending on + * the product used), refer to "HSE_VALUE". + * When HSE is used as system clock source, directly or through PLL, and you + * are using different crystal you have to adapt the HSE value to your own + * configuration. + * + ****************************************************************************** + * @attention + * + * Copyright (c) 2017 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 stm32f1xx_system + * @{ + */ + +/** @addtogroup STM32F1xx_System_Private_Includes + * @{ + */ + +#include "stm32f1xx.h" + +/** + * @} + */ + +/** @addtogroup STM32F1xx_System_Private_TypesDefinitions + * @{ + */ + +/** + * @} + */ + +/** @addtogroup STM32F1xx_System_Private_Defines + * @{ + */ + +#if !defined (HSE_VALUE) + #define HSE_VALUE 8000000U /*!< 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 8000000U /*!< Default value of the Internal oscillator in Hz. + This value can be provided and adapted by the user application. */ +#endif /* HSI_VALUE */ + +/*!< Uncomment the following line if you need to use external SRAM */ +#if defined(STM32F100xE) || defined(STM32F101xE) || defined(STM32F101xG) || defined(STM32F103xE) || defined(STM32F103xG) +/* #define DATA_IN_ExtSRAM */ +#endif /* STM32F100xE || STM32F101xE || STM32F101xG || STM32F103xE || STM32F103xG */ + +/*!< Uncomment the following line if you need to relocate your vector Table in + Internal SRAM. */ +/* #define VECT_TAB_SRAM */ +#define VECT_TAB_OFFSET 0x00000000U /*!< Vector Table base offset field. + This value must be a multiple of 0x200. */ + + +/** + * @} + */ + +/** @addtogroup STM32F1xx_System_Private_Macros + * @{ + */ + +/** + * @} + */ + +/** @addtogroup STM32F1xx_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; then there + is no need to call the 2 first functions listed above, since SystemCoreClock + variable is updated automatically. + */ +uint32_t SystemCoreClock = 16000000; +const uint8_t AHBPrescTable[16U] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9}; +const uint8_t APBPrescTable[8U] = {0, 0, 0, 0, 1, 2, 3, 4}; + +/** + * @} + */ + +/** @addtogroup STM32F1xx_System_Private_FunctionPrototypes + * @{ + */ + +#if defined(STM32F100xE) || defined(STM32F101xE) || defined(STM32F101xG) || defined(STM32F103xE) || defined(STM32F103xG) +#ifdef DATA_IN_ExtSRAM + static void SystemInit_ExtMemCtl(void); +#endif /* DATA_IN_ExtSRAM */ +#endif /* STM32F100xE || STM32F101xE || STM32F101xG || STM32F103xE || STM32F103xG */ + +/** + * @} + */ + +/** @addtogroup STM32F1xx_System_Private_Functions + * @{ + */ + +/** + * @brief Setup the microcontroller system + * Initialize the Embedded Flash Interface, the PLL and update the + * SystemCoreClock variable. + * @note This function should be used only after reset. + * @param None + * @retval None + */ +void SystemInit (void) +{ + /* Reset the RCC clock configuration to the default reset state(for debug purpose) */ + /* Set HSION bit */ + RCC->CR |= 0x00000001U; + + /* Reset SW, HPRE, PPRE1, PPRE2, ADCPRE and MCO bits */ +#if !defined(STM32F105xC) && !defined(STM32F107xC) + RCC->CFGR &= 0xF8FF0000U; +#else + RCC->CFGR &= 0xF0FF0000U; +#endif /* STM32F105xC */ + + /* Reset HSEON, CSSON and PLLON bits */ + RCC->CR &= 0xFEF6FFFFU; + + /* Reset HSEBYP bit */ + RCC->CR &= 0xFFFBFFFFU; + + /* Reset PLLSRC, PLLXTPRE, PLLMUL and USBPRE/OTGFSPRE bits */ + RCC->CFGR &= 0xFF80FFFFU; + +#if defined(STM32F105xC) || defined(STM32F107xC) + /* Reset PLL2ON and PLL3ON bits */ + RCC->CR &= 0xEBFFFFFFU; + + /* Disable all interrupts and clear pending bits */ + RCC->CIR = 0x00FF0000U; + + /* Reset CFGR2 register */ + RCC->CFGR2 = 0x00000000U; +#elif defined(STM32F100xB) || defined(STM32F100xE) + /* Disable all interrupts and clear pending bits */ + RCC->CIR = 0x009F0000U; + + /* Reset CFGR2 register */ + RCC->CFGR2 = 0x00000000U; +#else + /* Disable all interrupts and clear pending bits */ + RCC->CIR = 0x009F0000U; +#endif /* STM32F105xC */ + +#if defined(STM32F100xE) || defined(STM32F101xE) || defined(STM32F101xG) || defined(STM32F103xE) || defined(STM32F103xG) + #ifdef DATA_IN_ExtSRAM + SystemInit_ExtMemCtl(); + #endif /* DATA_IN_ExtSRAM */ +#endif + +#ifdef VECT_TAB_SRAM + SCB->VTOR = SRAM_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal SRAM. */ +#else + SCB->VTOR = FLASH_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal FLASH. */ +#endif +} + +/** + * @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 by the PLL factors. + * + * (*) HSI_VALUE is a constant defined in stm32f1xx.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 stm32f1xx.h file (default value + * 8 MHz or 25 MHz, depending on the product used), 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 = 0U, pllmull = 0U, pllsource = 0U; + +#if defined(STM32F105xC) || defined(STM32F107xC) + uint32_t prediv1source = 0U, prediv1factor = 0U, prediv2factor = 0U, pll2mull = 0U; +#endif /* STM32F105xC */ + +#if defined(STM32F100xB) || defined(STM32F100xE) + uint32_t prediv1factor = 0U; +#endif /* STM32F100xB or STM32F100xE */ + + /* Get SYSCLK source -------------------------------------------------------*/ + tmp = RCC->CFGR & RCC_CFGR_SWS; + + switch (tmp) + { + case 0x00U: /* HSI used as system clock */ + SystemCoreClock = HSI_VALUE; + break; + case 0x04U: /* HSE used as system clock */ + SystemCoreClock = HSE_VALUE; + break; + case 0x08U: /* PLL used as system clock */ + + /* Get PLL clock source and multiplication factor ----------------------*/ + pllmull = RCC->CFGR & RCC_CFGR_PLLMULL; + pllsource = RCC->CFGR & RCC_CFGR_PLLSRC; + +#if !defined(STM32F105xC) && !defined(STM32F107xC) + pllmull = ( pllmull >> 18U) + 2U; + + if (pllsource == 0x00U) + { + /* HSI oscillator clock divided by 2 selected as PLL clock entry */ + SystemCoreClock = (HSI_VALUE >> 1U) * pllmull; + } + else + { + #if defined(STM32F100xB) || defined(STM32F100xE) + prediv1factor = (RCC->CFGR2 & RCC_CFGR2_PREDIV1) + 1U; + /* HSE oscillator clock selected as PREDIV1 clock entry */ + SystemCoreClock = (HSE_VALUE / prediv1factor) * pllmull; + #else + /* HSE selected as PLL clock entry */ + if ((RCC->CFGR & RCC_CFGR_PLLXTPRE) != (uint32_t)RESET) + {/* HSE oscillator clock divided by 2 */ + SystemCoreClock = (HSE_VALUE >> 1U) * pllmull; + } + else + { + SystemCoreClock = HSE_VALUE * pllmull; + } + #endif + } +#else + pllmull = pllmull >> 18U; + + if (pllmull != 0x0DU) + { + pllmull += 2U; + } + else + { /* PLL multiplication factor = PLL input clock * 6.5 */ + pllmull = 13U / 2U; + } + + if (pllsource == 0x00U) + { + /* HSI oscillator clock divided by 2 selected as PLL clock entry */ + SystemCoreClock = (HSI_VALUE >> 1U) * pllmull; + } + else + {/* PREDIV1 selected as PLL clock entry */ + + /* Get PREDIV1 clock source and division factor */ + prediv1source = RCC->CFGR2 & RCC_CFGR2_PREDIV1SRC; + prediv1factor = (RCC->CFGR2 & RCC_CFGR2_PREDIV1) + 1U; + + if (prediv1source == 0U) + { + /* HSE oscillator clock selected as PREDIV1 clock entry */ + SystemCoreClock = (HSE_VALUE / prediv1factor) * pllmull; + } + else + {/* PLL2 clock selected as PREDIV1 clock entry */ + + /* Get PREDIV2 division factor and PLL2 multiplication factor */ + prediv2factor = ((RCC->CFGR2 & RCC_CFGR2_PREDIV2) >> 4U) + 1U; + pll2mull = ((RCC->CFGR2 & RCC_CFGR2_PLL2MUL) >> 8U) + 2U; + SystemCoreClock = (((HSE_VALUE / prediv2factor) * pll2mull) / prediv1factor) * pllmull; + } + } +#endif /* STM32F105xC */ + break; + + default: + SystemCoreClock = HSI_VALUE; + break; + } + + /* Compute HCLK clock frequency ----------------*/ + /* Get HCLK prescaler */ + tmp = AHBPrescTable[((RCC->CFGR & RCC_CFGR_HPRE) >> 4U)]; + /* HCLK clock frequency */ + SystemCoreClock >>= tmp; +} + +#if defined(STM32F100xE) || defined(STM32F101xE) || defined(STM32F101xG) || defined(STM32F103xE) || defined(STM32F103xG) +/** + * @brief Setup the external memory controller. Called in startup_stm32f1xx.s + * before jump to __main + * @param None + * @retval None + */ +#ifdef DATA_IN_ExtSRAM +/** + * @brief Setup the external memory controller. + * Called in startup_stm32f1xx_xx.s/.c before jump to main. + * This function configures the external SRAM mounted on STM3210E-EVAL + * board (STM32 High density devices). This SRAM will be used as program + * data memory (including heap and stack). + * @param None + * @retval None + */ +void SystemInit_ExtMemCtl(void) +{ + __IO uint32_t tmpreg; + /*!< FSMC Bank1 NOR/SRAM3 is used for the STM3210E-EVAL, if another Bank is + required, then adjust the Register Addresses */ + + /* Enable FSMC clock */ + RCC->AHBENR = 0x00000114U; + + /* Delay after an RCC peripheral clock enabling */ + tmpreg = READ_BIT(RCC->AHBENR, RCC_AHBENR_FSMCEN); + + /* Enable GPIOD, GPIOE, GPIOF and GPIOG clocks */ + RCC->APB2ENR = 0x000001E0U; + + /* Delay after an RCC peripheral clock enabling */ + tmpreg = READ_BIT(RCC->APB2ENR, RCC_APB2ENR_IOPDEN); + + (void)(tmpreg); + +/* --------------- SRAM Data lines, NOE and NWE configuration ---------------*/ +/*---------------- SRAM Address lines configuration -------------------------*/ +/*---------------- NOE and NWE configuration --------------------------------*/ +/*---------------- NE3 configuration ----------------------------------------*/ +/*---------------- NBL0, NBL1 configuration ---------------------------------*/ + + GPIOD->CRL = 0x44BB44BBU; + GPIOD->CRH = 0xBBBBBBBBU; + + GPIOE->CRL = 0xB44444BBU; + GPIOE->CRH = 0xBBBBBBBBU; + + GPIOF->CRL = 0x44BBBBBBU; + GPIOF->CRH = 0xBBBB4444U; + + GPIOG->CRL = 0x44BBBBBBU; + GPIOG->CRH = 0x444B4B44U; + +/*---------------- FSMC Configuration ---------------------------------------*/ +/*---------------- Enable FSMC Bank1_SRAM Bank ------------------------------*/ + + FSMC_Bank1->BTCR[4U] = 0x00001091U; + FSMC_Bank1->BTCR[5U] = 0x00110212U; +} +#endif /* DATA_IN_ExtSRAM */ +#endif /* STM32F100xE || STM32F101xE || STM32F101xG || STM32F103xE || STM32F103xG */ + +/** + * @} + */ + +/** + * @} + */ + +/** + * @} + */ |