/** ****************************************************************************** * @file system_stm32f2xx.c * @author MCD Application Team * @version V1.0.0 * @date 18-April-2011 * @brief CMSIS Cortex-M3 Device Peripheral Access Layer System Source File. * This file contains the system clock configuration for STM32F2xx devices, * and is generated by the clock configuration tool * "STM32f2xx_Clock_Configuration_V1.0.0.xls" * * 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 * and Divider factors, AHB/APBx prescalers and Flash settings), * depending on the configuration made in the clock xls tool. * This function is called at startup just after reset and * before branch to main program. This call is made inside * the "startup_stm32f2xx.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 (16 MHz) is used as system clock source. * Then SystemInit() function is called, in "startup_stm32f2xx.s" file, to * configure the system clock before to branch to main program. * * 3. If the system clock source selected by user fails to startup, the SystemInit() * function will do nothing and HSI still used as system clock source. User can * add some code to deal with this issue inside the SetSysClock() function. * * 4. The default value of HSE crystal is set to 25MHz, refer to "HSE_VALUE" define * in "stm32f2xx.h" file. 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. * * 5. This file configures the system clock as follows: *============================================================================= *============================================================================= * Supported STM32F2xx device revision | Rev B and Y *----------------------------------------------------------------------------- * System Clock source | PLL (HSE) *----------------------------------------------------------------------------- * SYSCLK(Hz) | 100000000 *----------------------------------------------------------------------------- * HCLK(Hz) | 100000000 *----------------------------------------------------------------------------- * AHB Prescaler | 1 *----------------------------------------------------------------------------- * APB1 Prescaler | 4 *----------------------------------------------------------------------------- * APB2 Prescaler | 2 *----------------------------------------------------------------------------- * HSE Frequency(Hz) | 25000000 *----------------------------------------------------------------------------- * PLL_M | 25 *----------------------------------------------------------------------------- * PLL_N | 200 *----------------------------------------------------------------------------- * PLL_P | 2 *----------------------------------------------------------------------------- * PLL_Q | 5 *----------------------------------------------------------------------------- * PLLI2S_N | NA *----------------------------------------------------------------------------- * PLLI2S_R | NA *----------------------------------------------------------------------------- * I2S input clock | NA *----------------------------------------------------------------------------- * VDD(V) | 3.3 *----------------------------------------------------------------------------- * Flash Latency(WS) | 3 *----------------------------------------------------------------------------- * Prefetch Buffer | ON *----------------------------------------------------------------------------- * Instruction cache | ON *----------------------------------------------------------------------------- * Data cache | ON *----------------------------------------------------------------------------- * Require 48MHz for USB OTG FS, | Enabled * SDIO and RNG clock | *----------------------------------------------------------------------------- *============================================================================= ****************************************************************************** * @attention * * THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS * WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE * TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY * DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING * FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE * CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS. * *

© COPYRIGHT 2011 STMicroelectronics

****************************************************************************** */ /** @addtogroup CMSIS * @{ */ /** @addtogroup stm32f2xx_system * @{ */ /** @addtogroup STM32F2xx_System_Private_Includes * @{ */ #include "stm32f2xx.h" /** * @} */ /** @addtogroup STM32F2xx_System_Private_TypesDefinitions * @{ */ /** * @} */ /** @addtogroup STM32F2xx_System_Private_Defines * @{ */ /*!< Uncomment the following line if you need to use external SRAM mounted on STM322xG_EVAL board as data memory */ /* #define DATA_IN_ExtSRAM */ /*!< 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. This value must be a multiple of 0x200. */ /* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLL_M) * PLL_N */ #define PLL_M 4 #define PLL_N 64 /* SYSCLK = PLL_VCO / PLL_P */ #define PLL_P 4 /* USB OTG FS, SDIO and RNG Clock = PLL_VCO / PLLQ */ #define PLL_Q 5 /** * @} */ /** @addtogroup STM32F2xx_System_Private_Macros * @{ */ /** * @} */ /** @addtogroup STM32F2xx_System_Private_Variables * @{ */ uint32_t SystemCoreClock = 100000000; __I uint8_t AHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9}; /** * @} */ /** @addtogroup STM32F2xx_System_Private_FunctionPrototypes * @{ */ static void SetSysClock(void); #ifdef DATA_IN_ExtSRAM static void SystemInit_ExtMemCtl(void); #endif /* DATA_IN_ExtSRAM */ /** * @} */ /** @addtogroup STM32F2xx_System_Private_Functions * @{ */ /** * @brief Setup the microcontroller system * Initialize the Embedded Flash Interface, the PLL and update the * SystemFrequency variable. * @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; /* Reset CFGR register */ RCC->CFGR = 0x00000000; /* Reset HSEON, CSSON and PLLON bits */ RCC->CR &= (uint32_t)0xFEF6FFFF; /* Reset PLLCFGR register */ RCC->PLLCFGR = 0x24003010; /* Reset HSEBYP bit */ RCC->CR &= (uint32_t)0xFFFBFFFF; /* Disable all interrupts */ RCC->CIR = 0x00000000; #ifdef DATA_IN_ExtSRAM SystemInit_ExtMemCtl(); #endif /* DATA_IN_ExtSRAM */ /* Configure the System clock source, PLL Multiplier and Divider factors, AHB/APBx prescalers and Flash settings ----------------------------------*/ SetSysClock(); /* Configure the Vector Table location add offset address ------------------*/ #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/divided by the PLL factors. * * (*) HSI_VALUE is a constant defined in stm32f2xx.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 stm32f2xx.h file (default value * 25 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, pllvco = 0, pllp = 2, pllsource = 0, pllm = 2; /* Get SYSCLK source -------------------------------------------------------*/ tmp = RCC->CFGR & RCC_CFGR_SWS; switch (tmp) { case 0x00: /* HSI used as system clock source */ SystemCoreClock = HSI_VALUE; break; case 0x04: /* HSE used as system clock source */ SystemCoreClock = HSE_VALUE; break; case 0x08: /* PLL used as system clock source */ /* 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 */ pllvco = (HSE_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6); } else { /* HSI used as PLL clock source */ pllvco = (HSI_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6); } pllp = (((RCC->PLLCFGR & RCC_PLLCFGR_PLLP) >>16) + 1 ) *2; SystemCoreClock = pllvco/pllp; break; default: SystemCoreClock = HSI_VALUE; break; } /* Compute HCLK frequency --------------------------------------------------*/ /* Get HCLK prescaler */ tmp = AHBPrescTable[((RCC->CFGR & RCC_CFGR_HPRE) >> 4)]; /* HCLK frequency */ SystemCoreClock >>= tmp; } /** * @brief Configures the System clock source, PLL Multiplier and Divider factors, * AHB/APBx prescalers and Flash settings * @Note This function should be called only once the RCC clock configuration * is reset to the default reset state (done in SystemInit() function). * @param None * @retval None */ static void SetSysClock(void) { /******************************************************************************/ /* PLL (clocked by HSE) used as System clock source */ /******************************************************************************/ __IO uint32_t StartUpCounter = 0, HSEStatus = 0; /* Enable HSE */ RCC->CR |= ((uint32_t)RCC_CR_HSEON); /* Wait till HSE is ready and if Time out is reached exit */ do { HSEStatus = RCC->CR & RCC_CR_HSERDY; StartUpCounter++; } while((HSEStatus == 0) && (StartUpCounter != HSE_STARTUP_TIMEOUT)); if ((RCC->CR & RCC_CR_HSERDY) != RESET) { HSEStatus = (uint32_t)0x01; } else { HSEStatus = (uint32_t)0x00; } if (HSEStatus == (uint32_t)0x01) { /* HCLK = SYSCLK / 1*/ RCC->CFGR |= RCC_CFGR_HPRE_DIV1; /* PCLK2 = HCLK / 2*/ RCC->CFGR |= RCC_CFGR_PPRE2_DIV2; /* PCLK1 = HCLK / 4*/ RCC->CFGR |= RCC_CFGR_PPRE1_DIV4; /* Configure the main PLL */ RCC->PLLCFGR = PLL_M | (PLL_N << 6) | (((PLL_P >> 1) -1) << 16) | (RCC_PLLCFGR_PLLSRC_HSE) | (PLL_Q << 24); /* Enable the main PLL */ RCC->CR |= RCC_CR_PLLON; /* Wait till the main PLL is ready */ while((RCC->CR & RCC_CR_PLLRDY) == 0) { } /* Configure Flash prefetch, Instruction cache, Data cache and wait state */ FLASH->ACR = FLASH_ACR_PRFTEN | FLASH_ACR_ICEN | FLASH_ACR_DCEN | FLASH_ACR_LATENCY_3WS; /* Select the main PLL as system clock source */ RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW)); RCC->CFGR |= RCC_CFGR_SW_PLL; /* Wait till the main PLL is used as system clock source */ while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS ) != RCC_CFGR_SWS_PLL); { } } else { /* If HSE fails to start-up, the application will have wrong clock configuration. User can add here some code to deal with this error */ } } /** * @brief Setup the external memory controller. Called in startup_stm32f2xx.s * before jump to __main * @param None * @retval None */ #ifdef DATA_IN_ExtSRAM /** * @brief Setup the external memory controller. * Called in startup_stm32f2xx.s before jump to main. * This function configures the external SRAM mounted on STM322xG_EVAL board * This SRAM will be used as program data memory (including heap and stack). * @param None * @retval None */ void SystemInit_ExtMemCtl(void) { /*-- GPIOs Configuration -----------------------------------------------------*/ /* +-------------------+--------------------+------------------+------------------+ + SRAM pins assignment + +-------------------+--------------------+------------------+------------------+ | PD0 <-> FSMC_D2 | PE0 <-> FSMC_NBL0 | PF0 <-> FSMC_A0 | PG0 <-> FSMC_A10 | | PD1 <-> FSMC_D3 | PE1 <-> FSMC_NBL1 | PF1 <-> FSMC_A1 | PG1 <-> FSMC_A11 | | PD4 <-> FSMC_NOE | PE7 <-> FSMC_D4 | PF2 <-> FSMC_A2 | PG2 <-> FSMC_A12 | | PD5 <-> FSMC_NWE | PE8 <-> FSMC_D5 | PF3 <-> FSMC_A3 | PG3 <-> FSMC_A13 | | PD8 <-> FSMC_D13 | PE9 <-> FSMC_D6 | PF4 <-> FSMC_A4 | PG4 <-> FSMC_A14 | | PD9 <-> FSMC_D14 | PE10 <-> FSMC_D7 | PF5 <-> FSMC_A5 | PG5 <-> FSMC_A15 | | PD10 <-> FSMC_D15 | PE11 <-> FSMC_D8 | PF12 <-> FSMC_A6 | PG9 <-> FSMC_NE2 | | PD11 <-> FSMC_A16 | PE12 <-> FSMC_D9 | PF13 <-> FSMC_A7 |------------------+ | PD12 <-> FSMC_A17 | PE13 <-> FSMC_D10 | PF14 <-> FSMC_A8 | | PD14 <-> FSMC_D0 | PE14 <-> FSMC_D11 | PF15 <-> FSMC_A9 | | PD15 <-> FSMC_D1 | PE15 <-> FSMC_D12 |------------------+ +-------------------+--------------------+ */ /* Enable GPIOD, GPIOE, GPIOF and GPIOG interface clock */ RCC->AHB1ENR = 0x00000078; /* Connect PDx pins to FSMC Alternate function */ GPIOD->AFR[0] = 0x00cc00cc; GPIOD->AFR[1] = 0xcc0ccccc; /* Configure PDx pins in Alternate function mode */ GPIOD->MODER = 0xa2aa0a0a; /* Configure PDx pins speed to 100 MHz */ GPIOD->OSPEEDR = 0xf3ff0f0f; /* Configure PDx pins Output type to push-pull */ GPIOD->OTYPER = 0x00000000; /* No pull-up, pull-down for PDx pins */ GPIOD->PUPDR = 0x00000000; /* Connect PEx pins to FSMC Alternate function */ GPIOE->AFR[0] = 0xc00000cc; GPIOE->AFR[1] = 0xcccccccc; /* Configure PEx pins in Alternate function mode */ GPIOE->MODER = 0xaaaa800a; /* Configure PEx pins speed to 100 MHz */ GPIOE->OSPEEDR = 0xffffc00f; /* Configure PEx pins Output type to push-pull */ GPIOE->OTYPER = 0x00000000; /* No pull-up, pull-down for PEx pins */ GPIOE->PUPDR = 0x00000000; /* Connect PFx pins to FSMC Alternate function */ GPIOF->AFR[0] = 0x00cccccc; GPIOF->AFR[1] = 0xcccc0000; /* Configure PFx pins in Alternate function mode */ GPIOF->MODER = 0xaa000aaa; /* Configure PFx pins speed to 100 MHz */ GPIOF->OSPEEDR = 0xff000fff; /* Configure PFx pins Output type to push-pull */ GPIOF->OTYPER = 0x00000000; /* No pull-up, pull-down for PFx pins */ GPIOF->PUPDR = 0x00000000; /* Connect PGx pins to FSMC Alternate function */ GPIOG->AFR[0] = 0x00cccccc; GPIOG->AFR[1] = 0x000000c0; /* Configure PGx pins in Alternate function mode */ GPIOG->MODER = 0x00080aaa; /* Configure PGx pins speed to 100 MHz */ GPIOG->OSPEEDR = 0x000c0fff; /* Configure PGx pins Output type to push-pull */ GPIOG->OTYPER = 0x00000000; /* No pull-up, pull-down for PGx pins */ GPIOG->PUPDR = 0x00000000; /*-- FSMC Configuration ------------------------------------------------------*/ /* Enable the FSMC interface clock */ RCC->AHB3ENR = 0x00000001; /* Configure and enable Bank1_SRAM2 */ FSMC_Bank1->BTCR[2] = 0x00001015; FSMC_Bank1->BTCR[3] = 0x00010400; FSMC_Bank1E->BWTR[2] = 0x0fffffff; /* Bank1_SRAM2 is configured as follow: p.FSMC_AddressSetupTime = 0; p.FSMC_AddressHoldTime = 0; p.FSMC_DataSetupTime = 4; p.FSMC_BusTurnAroundDuration = 1; p.FSMC_CLKDivision = 0; p.FSMC_DataLatency = 0; p.FSMC_AccessMode = FSMC_AccessMode_A; FSMC_NORSRAMInitStructure.FSMC_Bank = FSMC_Bank1_NORSRAM2; FSMC_NORSRAMInitStructure.FSMC_DataAddressMux = FSMC_DataAddressMux_Disable; FSMC_NORSRAMInitStructure.FSMC_MemoryType = FSMC_MemoryType_PSRAM; FSMC_NORSRAMInitStructure.FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_16b; FSMC_NORSRAMInitStructure.FSMC_BurstAccessMode = FSMC_BurstAccessMode_Disable; FSMC_NORSRAMInitStructure.FSMC_AsynchronousWait = FSMC_AsynchronousWait_Disable; FSMC_NORSRAMInitStructure.FSMC_WaitSignalPolarity = FSMC_WaitSignalPolarity_Low; FSMC_NORSRAMInitStructure.FSMC_WrapMode = FSMC_WrapMode_Disable; FSMC_NORSRAMInitStructure.FSMC_WaitSignalActive = FSMC_WaitSignalActive_BeforeWaitState; FSMC_NORSRAMInitStructure.FSMC_WriteOperation = FSMC_WriteOperation_Enable; FSMC_NORSRAMInitStructure.FSMC_WaitSignal = FSMC_WaitSignal_Disable; FSMC_NORSRAMInitStructure.FSMC_ExtendedMode = FSMC_ExtendedMode_Disable; FSMC_NORSRAMInitStructure.FSMC_WriteBurst = FSMC_WriteBurst_Disable; FSMC_NORSRAMInitStructure.FSMC_ReadWriteTimingStruct = &p; FSMC_NORSRAMInitStructure.FSMC_WriteTimingStruct = &p; */ } #endif /* DATA_IN_ExtSRAM */ /** * @} */ /** * @} */ /** * @} */ /******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/