shao ziyang
mbed library sources
Dependents: frdm_kl05z_gpio_test
Fork of
mbed-src
by 
mbed official
Diff: targets/cmsis/TARGET_STM/TARGET_STM32F3XX/system_stm32f30x.c
- Revision:
- 155:8435094ec241
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/cmsis/TARGET_STM/TARGET_STM32F3XX/system_stm32f30x.c Tue Apr 08 09:15:06 2014 +0100
@@ -0,0 +1,478 @@
+/**
+ ******************************************************************************
+ * @file system_stm32f30x.c
+ * @author MCD Application Team
+ * @version V1.0.0
+ * @date 05-March-2014
+ * @brief CMSIS Cortex-M4 Device Peripheral Access Layer System Source File.
+ * This file contains the system clock configuration for STM32F30x devices,
+ * and is generated by the clock configuration tool
+ * stm32f30x_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_stm32f30x.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_stm32f30x.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 8MHz, refer to "HSE_VALUE" define
+ * in "stm32f30x.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:
+ *-----------------------------------------------------------------------------
+ * System clock source | 1- PLL_HSE_EXTC | 3- PLL_HSI
+ * | (external 8 MHz clock) | (internal 8 MHz)
+ * | 2- PLL_HSE_XTAL |
+ * | (external 8 MHz xtal) |
+ *-----------------------------------------------------------------------------
+ * SYSCLK(MHz) | 72 | 64
+ *-----------------------------------------------------------------------------
+ * AHBCLK (MHz) | 72 | 64
+ *-----------------------------------------------------------------------------
+ * APB1CLK (MHz) | 36 | 32
+ *-----------------------------------------------------------------------------
+ * APB2CLK (MHz) | 72 | 64
+ *-----------------------------------------------------------------------------
+ * USB capable (48 MHz precise clock) | YES | NO
+ *-----------------------------------------------------------------------------
+ ******************************************************************************
+ * @attention
+ *
+ * <h2><center>© COPYRIGHT(c) 2014 STMicroelectronics</center></h2>
+ *
+ * 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 stm32f30x_system
+ * @{
+ */
+
+/** @addtogroup STM32F30x_System_Private_Includes
+ * @{
+ */
+
+#include "stm32f30x.h"
+
+/**
+ * @}
+ */
+
+/** @addtogroup STM32F30x_System_Private_TypesDefinitions
+ * @{
+ */
+
+/**
+ * @}
+ */
+
+/** @addtogroup STM32F30x_System_Private_Defines
+ * @{
+ */
+
+/*!< Uncomment the following line if you need to relocate your vector Table in
+ Internal SRAM. */
+/* #define VECT_TAB_SRAM */
+#define VECT_TAB_OFFSET 0x0 /*!< Vector Table base offset field.
+ This value must be a multiple of 0x200. */
+/**
+ * @}
+ */
+
+/** @addtogroup STM32F30x_System_Private_Macros
+ * @{
+ */
+
+/* Select the clock sources (other than HSI) to start with (0=OFF, 1=ON) */
+#define USE_PLL_HSE_EXTC (1) /* Use external clock */
+#define USE_PLL_HSE_XTAL (1) /* Use external xtal */
+
+/**
+ * @}
+ */
+
+/** @addtogroup STM32F30x_System_Private_Variables
+ * @{
+ */
+
+uint32_t SystemCoreClock = 64000000; /* Default with HSI. Will be updated if HSE is used */
+
+__I uint8_t AHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9};
+
+/**
+ * @}
+ */
+
+/** @addtogroup STM32F30x_System_Private_FunctionPrototypes
+ * @{
+ */
+
+void SetSysClock(void);
+
+#if (USE_PLL_HSE_XTAL != 0) || (USE_PLL_HSE_EXTC != 0)
+uint8_t SetSysClock_PLL_HSE(uint8_t bypass);
+#endif
+
+uint8_t SetSysClock_PLL_HSI(void);
+
+/**
+ * @}
+ */
+
+/** @addtogroup STM32F30x_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)
+{
+ /* FPU settings ------------------------------------------------------------*/
+ #if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
+ SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2)); /* set CP10 and CP11 Full Access */
+ #endif
+
+ /* Reset the RCC clock configuration to the default reset state ------------*/
+ /* Set HSION bit */
+ RCC->CR |= (uint32_t)0x00000001;
+
+ /* Reset CFGR register */
+ RCC->CFGR &= 0xF87FC00C;
+
+ /* Reset HSEON, CSSON and PLLON bits */
+ RCC->CR &= (uint32_t)0xFEF6FFFF;
+
+ /* Reset HSEBYP bit */
+ RCC->CR &= (uint32_t)0xFFFBFFFF;
+
+ /* Reset PLLSRC, PLLXTPRE, PLLMUL and USBPRE bits */
+ RCC->CFGR &= (uint32_t)0xFF80FFFF;
+
+ /* Reset PREDIV1[3:0] bits */
+ RCC->CFGR2 &= (uint32_t)0xFFFFFFF0;
+
+ /* Reset USARTSW[1:0], I2CSW and TIMs bits */
+ RCC->CFGR3 &= (uint32_t)0xFF00FCCC;
+
+ /* Disable all interrupts */
+ RCC->CIR = 0x00000000;
+
+ /* 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 stm32f30x.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 stm32f30x.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, prediv1factor = 0;
+
+ /* Get SYSCLK source -------------------------------------------------------*/
+ tmp = RCC->CFGR & RCC_CFGR_SWS;
+
+ switch (tmp)
+ {
+ case 0x00: /* HSI used as system clock */
+ SystemCoreClock = HSI_VALUE;
+ break;
+ case 0x04: /* HSE used as system clock */
+ SystemCoreClock = HSE_VALUE;
+ break;
+ case 0x08: /* PLL used as system clock */
+ /* Get PLL clock source and multiplication factor ----------------------*/
+ pllmull = RCC->CFGR & RCC_CFGR_PLLMULL;
+ pllsource = RCC->CFGR & RCC_CFGR_PLLSRC;
+ pllmull = ( pllmull >> 18) + 2;
+
+ if (pllsource == 0x00)
+ {
+ /* HSI oscillator clock divided by 2 selected as PLL clock entry */
+ SystemCoreClock = (HSI_VALUE >> 1) * pllmull;
+ }
+ else
+ {
+ prediv1factor = (RCC->CFGR2 & RCC_CFGR2_PREDIV1) + 1;
+ /* HSE oscillator clock selected as PREDIV1 clock entry */
+ SystemCoreClock = (HSE_VALUE / prediv1factor) * pllmull;
+ }
+ 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;
+}
+
+/**
+ * @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
+ */
+void SetSysClock(void)
+{
+ /* 1- Try to start with HSE and external clock */
+#if USE_PLL_HSE_EXTC != 0
+ if (SetSysClock_PLL_HSE(1) == 0)
+#endif
+ {
+ /* 2- If fail try to start with HSE and external xtal */
+ #if USE_PLL_HSE_XTAL != 0
+ if (SetSysClock_PLL_HSE(0) == 0)
+ #endif
+ {
+ /* 3- If fail start with HSI clock */
+ if (SetSysClock_PLL_HSI() == 0)
+ {
+ while(1)
+ {
+ // [TODO] Put something here to tell the user that a problem occured...
+ }
+ }
+ }
+ }
+
+ /* Output SYSCLK on MCO pin(PA8) for debugging purpose */
+ /*
+ // Enable GPIOA clock
+ RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
+ // Configure MCO pin (PA8)
+ GPIO_InitTypeDef GPIO_InitStructure;
+ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
+ GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
+ GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
+ GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
+ GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
+ GPIO_Init(GPIOA, &GPIO_InitStructure);
+ // Select the clock to output
+ RCC_MCOConfig(RCC_MCOSource_SYSCLK, RCC_MCOPrescaler_1);
+ */
+}
+
+#if (USE_PLL_HSE_XTAL != 0) || (USE_PLL_HSE_EXTC != 0)
+/******************************************************************************/
+/* PLL (clocked by HSE) used as System clock source */
+/******************************************************************************/
+uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
+{
+ __IO uint32_t StartUpCounter = 0;
+ __IO uint32_t HSEStatus = 0;
+
+ /* Bypass HSE: can be done only if HSE is OFF */
+ RCC->CR &= ((uint32_t)~RCC_CR_HSEON); /* To be sure HSE is OFF */
+ if (bypass != 0)
+ {
+ RCC->CR |= ((uint32_t)RCC_CR_HSEBYP);
+ }
+ else
+ {
+ RCC->CR &= ((uint32_t)~RCC_CR_HSEBYP);
+ }
+
+ /* Enable HSE */
+ RCC->CR |= ((uint32_t)RCC_CR_HSEON);
+
+ /* Wait till HSE is ready */
+ do
+ {
+ HSEStatus = RCC->CR & RCC_CR_HSERDY;
+ StartUpCounter++;
+ } while((HSEStatus == 0) && (StartUpCounter != HSE_STARTUP_TIMEOUT));
+
+ /* Check if HSE has started correctly */
+ if ((RCC->CR & RCC_CR_HSERDY) != RESET)
+ {
+ /* Enable prefetch buffer and set flash latency
+ 0WS for 0 < SYSCLK <= 24 MHz
+ 1WS for 24 < SYSCLK <= 48 MHz
+ 2WS for 48 < SYSCLK <= 72 MHz */
+ FLASH->ACR = FLASH_ACR_PRFTBE | (uint32_t)FLASH_ACR_LATENCY_1; /* 2 WS */
+
+ /* Warning: values are obtained with external xtal or clock = 8 MHz */
+ /* SYSCLK = 72 MHz (8 MHz * 9) */
+ RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLMULL));
+ RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_PREDIV1 | RCC_CFGR_PLLXTPRE_PREDIV1 | RCC_CFGR_PLLMULL9
+ | RCC_CFGR_HPRE_DIV1 /* HCLK = 72 MHz */
+ | RCC_CFGR_PPRE2_DIV1 /* PCLK2 = 72 MHz */
+ | RCC_CFGR_PPRE1_DIV2); /* PCLK1 = 36 MHz */
+ /* USBCLK = 48 MHz (72 MHz / 1.5) --> USB OK */
+
+ /* Enable PLL */
+ RCC->CR |= RCC_CR_PLLON;
+
+ /* Wait till PLL is ready */
+ while((RCC->CR & RCC_CR_PLLRDY) == 0)
+ {
+ }
+
+ /* Select PLL as system clock source */
+ RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
+ RCC->CFGR |= (uint32_t)RCC_CFGR_SW_PLL;
+
+ /* Wait till PLL is used as system clock source */
+ while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != (uint32_t)RCC_CFGR_SWS_PLL)
+ {
+ }
+
+ return 1; // OK
+ }
+ else
+ {
+ return 0; // FAIL
+ }
+}
+#endif
+
+/******************************************************************************/
+/* PLL (clocked by HSI) used as System clock source */
+/******************************************************************************/
+uint8_t SetSysClock_PLL_HSI(void)
+{
+ /* At this stage the HSI is already enabled and used as System clock source */
+
+ /* Enable prefetch buffer and set flash latency
+ 0WS for 0 < SYSCLK <= 24 MHz
+ 1WS for 24 < SYSCLK <= 48 MHz
+ 2WS for 48 < SYSCLK <= 72 MHz */
+ FLASH->ACR = FLASH_ACR_PRFTBE | (uint32_t)FLASH_ACR_LATENCY_1; /* 2 WS */
+
+ /* SYSCLK = 64 MHz (8 MHz / 2 * 16) */
+ RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLMULL));
+ RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_HSI_Div2 | RCC_CFGR_PLLXTPRE_PREDIV1 | RCC_CFGR_PLLMULL16
+ | RCC_CFGR_HPRE_DIV1 /* HCLK = 64 MHz */
+ | RCC_CFGR_PPRE2_DIV1 /* PCLK2 = 64 MHz */
+ | RCC_CFGR_PPRE1_DIV2); /* PCLK1 = 32 MHz */
+ /* USBCLK = 42.667 MHz (64 MHz / 1.5) --> USB NOT POSSIBLE */
+
+ /* Enable PLL */
+ RCC->CR |= RCC_CR_PLLON;
+
+ /* Wait till PLL is ready */
+ while((RCC->CR & RCC_CR_PLLRDY) == 0)
+ {
+ }
+
+ /* Select PLL as system clock source */
+ RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
+ RCC->CFGR |= (uint32_t)RCC_CFGR_SW_PLL;
+
+ /* Wait till PLL is used as system clock source */
+ while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != (uint32_t)RCC_CFGR_SWS_PLL)
+ {
+ }
+
+ return 1; // OK
+}
+
+/**
+ * @}
+ */
+
+/**
+ * @}
+ */
+
+/**
+ * @}
+ */
+
+/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/