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Last commit 20 Feb 2019 by mbed official

targets/cmsis/TARGET_STM/TARGET_NUCLEO_F302R8/system_stm32f30x.c@137:f9a97811e98c, 2014-03-25 (annotated)

Committer:
mbed_official
Date:
Tue Mar 25 13:45:07 2014 +0000
Revision:
137:f9a97811e98c
Parent:
135:067cc8ba23da
Child:
138:ec7ee4660c49
Synchronized with git revision 8b4f07882b14f6152ee6d3e1c72b548d6f340650



Full URL: https://github.com/mbedmicro/mbed/commit/8b4f07882b14f6152ee6d3e1c72b548d6f340650/



[NUCLEO_F302R8] Fix issue with SystemCoreClock variable update.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 125:23cc3068a9e4 1 /**
mbed_official 125:23cc3068a9e4 2 ******************************************************************************
mbed_official 125:23cc3068a9e4 3 * @file system_stm32f30x.c
mbed_official 125:23cc3068a9e4 4 * @author MCD Application Team
mbed_official 125:23cc3068a9e4 5 * @version V1.0.0
mbed_official 125:23cc3068a9e4 6 * @date 05-March-2014
mbed_official 125:23cc3068a9e4 7 * @brief CMSIS Cortex-M4 Device Peripheral Access Layer System Source File.
mbed_official 125:23cc3068a9e4 8 * This file contains the system clock configuration for STM32F30x devices,
mbed_official 125:23cc3068a9e4 9 * and is generated by the clock configuration tool
mbed_official 125:23cc3068a9e4 10 * stm32f30x_Clock_Configuration_V1.0.0.xls
mbed_official 125:23cc3068a9e4 11 *
mbed_official 125:23cc3068a9e4 12 * 1. This file provides two functions and one global variable to be called from
mbed_official 125:23cc3068a9e4 13 * user application:
mbed_official 125:23cc3068a9e4 14 * - SystemInit(): Setups the system clock (System clock source, PLL Multiplier
mbed_official 125:23cc3068a9e4 15 * and Divider factors, AHB/APBx prescalers and Flash settings),
mbed_official 125:23cc3068a9e4 16 * depending on the configuration made in the clock xls tool.
mbed_official 125:23cc3068a9e4 17 * This function is called at startup just after reset and
mbed_official 125:23cc3068a9e4 18 * before branch to main program. This call is made inside
mbed_official 125:23cc3068a9e4 19 * the "startup_stm32f30x.s" file.
mbed_official 125:23cc3068a9e4 20 *
mbed_official 125:23cc3068a9e4 21 * - SystemCoreClock variable: Contains the core clock (HCLK), it can be used
mbed_official 125:23cc3068a9e4 22 * by the user application to setup the SysTick
mbed_official 125:23cc3068a9e4 23 * timer or configure other parameters.
mbed_official 125:23cc3068a9e4 24 *
mbed_official 125:23cc3068a9e4 25 * - SystemCoreClockUpdate(): Updates the variable SystemCoreClock and must
mbed_official 125:23cc3068a9e4 26 * be called whenever the core clock is changed
mbed_official 125:23cc3068a9e4 27 * during program execution.
mbed_official 125:23cc3068a9e4 28 *
mbed_official 125:23cc3068a9e4 29 * 2. After each device reset the HSI (8 MHz) is used as system clock source.
mbed_official 125:23cc3068a9e4 30 * Then SystemInit() function is called, in "startup_stm32f30x.s" file, to
mbed_official 125:23cc3068a9e4 31 * configure the system clock before to branch to main program.
mbed_official 125:23cc3068a9e4 32 *
mbed_official 125:23cc3068a9e4 33 * 3. If the system clock source selected by user fails to startup, the SystemInit()
mbed_official 125:23cc3068a9e4 34 * function will do nothing and HSI still used as system clock source. User can
mbed_official 125:23cc3068a9e4 35 * add some code to deal with this issue inside the SetSysClock() function.
mbed_official 125:23cc3068a9e4 36 *
mbed_official 125:23cc3068a9e4 37 * 4. The default value of HSE crystal is set to 8MHz, refer to "HSE_VALUE" define
mbed_official 125:23cc3068a9e4 38 * in "stm32f30x.h" file. When HSE is used as system clock source, directly or
mbed_official 125:23cc3068a9e4 39 * through PLL, and you are using different crystal you have to adapt the HSE
mbed_official 125:23cc3068a9e4 40 * value to your own configuration.
mbed_official 125:23cc3068a9e4 41 *
mbed_official 125:23cc3068a9e4 42 * 5. This file configures the system clock as follows:
mbed_official 125:23cc3068a9e4 43 *-----------------------------------------------------------------------------
mbed_official 135:067cc8ba23da 44 * System clock source | 1- PLL_HSE_EXTC | 3- PLL_HSI
mbed_official 135:067cc8ba23da 45 * | (external 8 MHz clock) | (internal 8 MHz)
mbed_official 135:067cc8ba23da 46 * | 2- PLL_HSE_XTAL |
mbed_official 135:067cc8ba23da 47 * | (external 8 MHz xtal) |
mbed_official 125:23cc3068a9e4 48 *-----------------------------------------------------------------------------
mbed_official 135:067cc8ba23da 49 * SYSCLK(MHz) | 72 | 64
mbed_official 125:23cc3068a9e4 50 *-----------------------------------------------------------------------------
mbed_official 135:067cc8ba23da 51 * AHBCLK (MHz) | 72 | 64
mbed_official 125:23cc3068a9e4 52 *-----------------------------------------------------------------------------
mbed_official 135:067cc8ba23da 53 * APB1CLK (MHz) | 36 | 32
mbed_official 125:23cc3068a9e4 54 *-----------------------------------------------------------------------------
mbed_official 135:067cc8ba23da 55 * APB2CLK (MHz) | 72 | 64
mbed_official 125:23cc3068a9e4 56 *-----------------------------------------------------------------------------
mbed_official 135:067cc8ba23da 57 * USB capable (48 MHz precise clock) | YES | NO
mbed_official 135:067cc8ba23da 58 *-----------------------------------------------------------------------------
mbed_official 125:23cc3068a9e4 59 ******************************************************************************
mbed_official 125:23cc3068a9e4 60 * @attention
mbed_official 125:23cc3068a9e4 61 *
mbed_official 125:23cc3068a9e4 62 * <h2><center>&copy; COPYRIGHT(c) 2014 STMicroelectronics</center></h2>
mbed_official 125:23cc3068a9e4 63 *
mbed_official 125:23cc3068a9e4 64 * Redistribution and use in source and binary forms, with or without modification,
mbed_official 125:23cc3068a9e4 65 * are permitted provided that the following conditions are met:
mbed_official 125:23cc3068a9e4 66 * 1. Redistributions of source code must retain the above copyright notice,
mbed_official 125:23cc3068a9e4 67 * this list of conditions and the following disclaimer.
mbed_official 125:23cc3068a9e4 68 * 2. Redistributions in binary form must reproduce the above copyright notice,
mbed_official 125:23cc3068a9e4 69 * this list of conditions and the following disclaimer in the documentation
mbed_official 125:23cc3068a9e4 70 * and/or other materials provided with the distribution.
mbed_official 125:23cc3068a9e4 71 * 3. Neither the name of STMicroelectronics nor the names of its contributors
mbed_official 125:23cc3068a9e4 72 * may be used to endorse or promote products derived from this software
mbed_official 125:23cc3068a9e4 73 * without specific prior written permission.
mbed_official 125:23cc3068a9e4 74 *
mbed_official 125:23cc3068a9e4 75 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
mbed_official 125:23cc3068a9e4 76 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
mbed_official 125:23cc3068a9e4 77 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
mbed_official 125:23cc3068a9e4 78 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
mbed_official 125:23cc3068a9e4 79 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
mbed_official 125:23cc3068a9e4 80 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
mbed_official 125:23cc3068a9e4 81 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
mbed_official 125:23cc3068a9e4 82 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
mbed_official 125:23cc3068a9e4 83 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
mbed_official 125:23cc3068a9e4 84 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
mbed_official 125:23cc3068a9e4 85 *
mbed_official 125:23cc3068a9e4 86 ******************************************************************************
mbed_official 125:23cc3068a9e4 87 */
mbed_official 135:067cc8ba23da 88
mbed_official 125:23cc3068a9e4 89 /** @addtogroup CMSIS
mbed_official 125:23cc3068a9e4 90 * @{
mbed_official 125:23cc3068a9e4 91 */
mbed_official 125:23cc3068a9e4 92
mbed_official 125:23cc3068a9e4 93 /** @addtogroup stm32f30x_system
mbed_official 125:23cc3068a9e4 94 * @{
mbed_official 125:23cc3068a9e4 95 */
mbed_official 125:23cc3068a9e4 96
mbed_official 125:23cc3068a9e4 97 /** @addtogroup STM32F30x_System_Private_Includes
mbed_official 125:23cc3068a9e4 98 * @{
mbed_official 125:23cc3068a9e4 99 */
mbed_official 125:23cc3068a9e4 100
mbed_official 125:23cc3068a9e4 101 #include "stm32f30x.h"
mbed_official 125:23cc3068a9e4 102
mbed_official 125:23cc3068a9e4 103 /**
mbed_official 125:23cc3068a9e4 104 * @}
mbed_official 125:23cc3068a9e4 105 */
mbed_official 125:23cc3068a9e4 106
mbed_official 125:23cc3068a9e4 107 /** @addtogroup STM32F30x_System_Private_TypesDefinitions
mbed_official 125:23cc3068a9e4 108 * @{
mbed_official 125:23cc3068a9e4 109 */
mbed_official 125:23cc3068a9e4 110
mbed_official 125:23cc3068a9e4 111 /**
mbed_official 125:23cc3068a9e4 112 * @}
mbed_official 125:23cc3068a9e4 113 */
mbed_official 125:23cc3068a9e4 114
mbed_official 125:23cc3068a9e4 115 /** @addtogroup STM32F30x_System_Private_Defines
mbed_official 125:23cc3068a9e4 116 * @{
mbed_official 125:23cc3068a9e4 117 */
mbed_official 135:067cc8ba23da 118
mbed_official 125:23cc3068a9e4 119 /*!< Uncomment the following line if you need to relocate your vector Table in
mbed_official 125:23cc3068a9e4 120 Internal SRAM. */
mbed_official 125:23cc3068a9e4 121 /* #define VECT_TAB_SRAM */
mbed_official 125:23cc3068a9e4 122 #define VECT_TAB_OFFSET 0x0 /*!< Vector Table base offset field.
mbed_official 125:23cc3068a9e4 123 This value must be a multiple of 0x200. */
mbed_official 125:23cc3068a9e4 124 /**
mbed_official 125:23cc3068a9e4 125 * @}
mbed_official 125:23cc3068a9e4 126 */
mbed_official 125:23cc3068a9e4 127
mbed_official 125:23cc3068a9e4 128 /** @addtogroup STM32F30x_System_Private_Macros
mbed_official 125:23cc3068a9e4 129 * @{
mbed_official 125:23cc3068a9e4 130 */
mbed_official 125:23cc3068a9e4 131
mbed_official 135:067cc8ba23da 132 /* Select the clock sources (other than HSI) to start with (0=OFF, 1=ON) */
mbed_official 135:067cc8ba23da 133 #define USE_PLL_HSE_EXTC (1) /* Use external clock */
mbed_official 135:067cc8ba23da 134 #define USE_PLL_HSE_XTAL (1) /* Use external xtal */
mbed_official 135:067cc8ba23da 135
mbed_official 125:23cc3068a9e4 136 /**
mbed_official 125:23cc3068a9e4 137 * @}
mbed_official 125:23cc3068a9e4 138 */
mbed_official 125:23cc3068a9e4 139
mbed_official 125:23cc3068a9e4 140 /** @addtogroup STM32F30x_System_Private_Variables
mbed_official 125:23cc3068a9e4 141 * @{
mbed_official 125:23cc3068a9e4 142 */
mbed_official 125:23cc3068a9e4 143
mbed_official 137:f9a97811e98c 144 // [TODO] Do the same for other compilers
mbed_official 137:f9a97811e98c 145 // Warning: the RAM is initialized AFTER the SetSysClock function is called.
mbed_official 137:f9a97811e98c 146 // This variable must be placed outside the initialized section (see scatter file).
mbed_official 137:f9a97811e98c 147 uint32_t SystemCoreClock __attribute__((at(0x20000188))) = 64000000; /* Default with HSI. Will be updated if HSE is used */
mbed_official 125:23cc3068a9e4 148
mbed_official 135:067cc8ba23da 149 __I uint8_t AHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9};
mbed_official 125:23cc3068a9e4 150
mbed_official 125:23cc3068a9e4 151 /**
mbed_official 125:23cc3068a9e4 152 * @}
mbed_official 125:23cc3068a9e4 153 */
mbed_official 125:23cc3068a9e4 154
mbed_official 125:23cc3068a9e4 155 /** @addtogroup STM32F30x_System_Private_FunctionPrototypes
mbed_official 125:23cc3068a9e4 156 * @{
mbed_official 125:23cc3068a9e4 157 */
mbed_official 125:23cc3068a9e4 158
mbed_official 125:23cc3068a9e4 159 void SetSysClock(void);
mbed_official 125:23cc3068a9e4 160
mbed_official 135:067cc8ba23da 161 #if (USE_PLL_HSE_XTAL != 0) || (USE_PLL_HSE_EXTC != 0)
mbed_official 135:067cc8ba23da 162 uint8_t SetSysClock_PLL_HSE(uint8_t bypass);
mbed_official 135:067cc8ba23da 163 #endif
mbed_official 135:067cc8ba23da 164
mbed_official 135:067cc8ba23da 165 uint8_t SetSysClock_PLL_HSI(void);
mbed_official 135:067cc8ba23da 166
mbed_official 125:23cc3068a9e4 167 /**
mbed_official 125:23cc3068a9e4 168 * @}
mbed_official 125:23cc3068a9e4 169 */
mbed_official 125:23cc3068a9e4 170
mbed_official 125:23cc3068a9e4 171 /** @addtogroup STM32F30x_System_Private_Functions
mbed_official 125:23cc3068a9e4 172 * @{
mbed_official 125:23cc3068a9e4 173 */
mbed_official 125:23cc3068a9e4 174
mbed_official 125:23cc3068a9e4 175 /**
mbed_official 125:23cc3068a9e4 176 * @brief Setup the microcontroller system
mbed_official 125:23cc3068a9e4 177 * Initialize the Embedded Flash Interface, the PLL and update the
mbed_official 125:23cc3068a9e4 178 * SystemFrequency variable.
mbed_official 125:23cc3068a9e4 179 * @param None
mbed_official 125:23cc3068a9e4 180 * @retval None
mbed_official 125:23cc3068a9e4 181 */
mbed_official 125:23cc3068a9e4 182 void SystemInit(void)
mbed_official 125:23cc3068a9e4 183 {
mbed_official 125:23cc3068a9e4 184 /* FPU settings ------------------------------------------------------------*/
mbed_official 125:23cc3068a9e4 185 #if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
mbed_official 125:23cc3068a9e4 186 SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2)); /* set CP10 and CP11 Full Access */
mbed_official 125:23cc3068a9e4 187 #endif
mbed_official 125:23cc3068a9e4 188
mbed_official 125:23cc3068a9e4 189 /* Reset the RCC clock configuration to the default reset state ------------*/
mbed_official 125:23cc3068a9e4 190 /* Set HSION bit */
mbed_official 125:23cc3068a9e4 191 RCC->CR |= (uint32_t)0x00000001;
mbed_official 125:23cc3068a9e4 192
mbed_official 125:23cc3068a9e4 193 /* Reset CFGR register */
mbed_official 125:23cc3068a9e4 194 RCC->CFGR &= 0xF87FC00C;
mbed_official 125:23cc3068a9e4 195
mbed_official 125:23cc3068a9e4 196 /* Reset HSEON, CSSON and PLLON bits */
mbed_official 125:23cc3068a9e4 197 RCC->CR &= (uint32_t)0xFEF6FFFF;
mbed_official 125:23cc3068a9e4 198
mbed_official 125:23cc3068a9e4 199 /* Reset HSEBYP bit */
mbed_official 125:23cc3068a9e4 200 RCC->CR &= (uint32_t)0xFFFBFFFF;
mbed_official 125:23cc3068a9e4 201
mbed_official 125:23cc3068a9e4 202 /* Reset PLLSRC, PLLXTPRE, PLLMUL and USBPRE bits */
mbed_official 125:23cc3068a9e4 203 RCC->CFGR &= (uint32_t)0xFF80FFFF;
mbed_official 125:23cc3068a9e4 204
mbed_official 125:23cc3068a9e4 205 /* Reset PREDIV1[3:0] bits */
mbed_official 125:23cc3068a9e4 206 RCC->CFGR2 &= (uint32_t)0xFFFFFFF0;
mbed_official 125:23cc3068a9e4 207
mbed_official 125:23cc3068a9e4 208 /* Reset USARTSW[1:0], I2CSW and TIMs bits */
mbed_official 125:23cc3068a9e4 209 RCC->CFGR3 &= (uint32_t)0xFF00FCCC;
mbed_official 125:23cc3068a9e4 210
mbed_official 125:23cc3068a9e4 211 /* Disable all interrupts */
mbed_official 125:23cc3068a9e4 212 RCC->CIR = 0x00000000;
mbed_official 125:23cc3068a9e4 213
mbed_official 137:f9a97811e98c 214 /* Configure the System clock source, PLL Multiplier and Divider factors,
mbed_official 137:f9a97811e98c 215 AHB/APBx prescalers and Flash settings */
mbed_official 137:f9a97811e98c 216 SetSysClock();
mbed_official 137:f9a97811e98c 217
mbed_official 135:067cc8ba23da 218 /* Configure the Vector Table location add offset address ------------------*/
mbed_official 125:23cc3068a9e4 219 #ifdef VECT_TAB_SRAM
mbed_official 135:067cc8ba23da 220 SCB->VTOR = SRAM_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal SRAM */
mbed_official 125:23cc3068a9e4 221 #else
mbed_official 135:067cc8ba23da 222 SCB->VTOR = FLASH_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal FLASH */
mbed_official 125:23cc3068a9e4 223 #endif
mbed_official 125:23cc3068a9e4 224 }
mbed_official 125:23cc3068a9e4 225
mbed_official 125:23cc3068a9e4 226 /**
mbed_official 125:23cc3068a9e4 227 * @brief Update SystemCoreClock variable according to Clock Register Values.
mbed_official 125:23cc3068a9e4 228 * The SystemCoreClock variable contains the core clock (HCLK), it can
mbed_official 125:23cc3068a9e4 229 * be used by the user application to setup the SysTick timer or configure
mbed_official 125:23cc3068a9e4 230 * other parameters.
mbed_official 125:23cc3068a9e4 231 *
mbed_official 125:23cc3068a9e4 232 * @note Each time the core clock (HCLK) changes, this function must be called
mbed_official 125:23cc3068a9e4 233 * to update SystemCoreClock variable value. Otherwise, any configuration
mbed_official 125:23cc3068a9e4 234 * based on this variable will be incorrect.
mbed_official 125:23cc3068a9e4 235 *
mbed_official 125:23cc3068a9e4 236 * @note - The system frequency computed by this function is not the real
mbed_official 125:23cc3068a9e4 237 * frequency in the chip. It is calculated based on the predefined
mbed_official 125:23cc3068a9e4 238 * constant and the selected clock source:
mbed_official 125:23cc3068a9e4 239 *
mbed_official 125:23cc3068a9e4 240 * - If SYSCLK source is HSI, SystemCoreClock will contain the HSI_VALUE(*)
mbed_official 125:23cc3068a9e4 241 *
mbed_official 125:23cc3068a9e4 242 * - If SYSCLK source is HSE, SystemCoreClock will contain the HSE_VALUE(**)
mbed_official 125:23cc3068a9e4 243 *
mbed_official 125:23cc3068a9e4 244 * - If SYSCLK source is PLL, SystemCoreClock will contain the HSE_VALUE(**)
mbed_official 125:23cc3068a9e4 245 * or HSI_VALUE(*) multiplied/divided by the PLL factors.
mbed_official 125:23cc3068a9e4 246 *
mbed_official 125:23cc3068a9e4 247 * (*) HSI_VALUE is a constant defined in stm32f30x.h file (default value
mbed_official 125:23cc3068a9e4 248 * 8 MHz) but the real value may vary depending on the variations
mbed_official 125:23cc3068a9e4 249 * in voltage and temperature.
mbed_official 125:23cc3068a9e4 250 *
mbed_official 125:23cc3068a9e4 251 * (**) HSE_VALUE is a constant defined in stm32f30x.h file (default value
mbed_official 125:23cc3068a9e4 252 * 8 MHz), user has to ensure that HSE_VALUE is same as the real
mbed_official 125:23cc3068a9e4 253 * frequency of the crystal used. Otherwise, this function may
mbed_official 125:23cc3068a9e4 254 * have wrong result.
mbed_official 125:23cc3068a9e4 255 *
mbed_official 125:23cc3068a9e4 256 * - The result of this function could be not correct when using fractional
mbed_official 125:23cc3068a9e4 257 * value for HSE crystal.
mbed_official 125:23cc3068a9e4 258 *
mbed_official 125:23cc3068a9e4 259 * @param None
mbed_official 125:23cc3068a9e4 260 * @retval None
mbed_official 125:23cc3068a9e4 261 */
mbed_official 125:23cc3068a9e4 262 void SystemCoreClockUpdate (void)
mbed_official 125:23cc3068a9e4 263 {
mbed_official 125:23cc3068a9e4 264 uint32_t tmp = 0, pllmull = 0, pllsource = 0, prediv1factor = 0;
mbed_official 125:23cc3068a9e4 265
mbed_official 125:23cc3068a9e4 266 /* Get SYSCLK source -------------------------------------------------------*/
mbed_official 125:23cc3068a9e4 267 tmp = RCC->CFGR & RCC_CFGR_SWS;
mbed_official 125:23cc3068a9e4 268
mbed_official 125:23cc3068a9e4 269 switch (tmp)
mbed_official 125:23cc3068a9e4 270 {
mbed_official 125:23cc3068a9e4 271 case 0x00: /* HSI used as system clock */
mbed_official 125:23cc3068a9e4 272 SystemCoreClock = HSI_VALUE;
mbed_official 125:23cc3068a9e4 273 break;
mbed_official 125:23cc3068a9e4 274 case 0x04: /* HSE used as system clock */
mbed_official 125:23cc3068a9e4 275 SystemCoreClock = HSE_VALUE;
mbed_official 125:23cc3068a9e4 276 break;
mbed_official 125:23cc3068a9e4 277 case 0x08: /* PLL used as system clock */
mbed_official 125:23cc3068a9e4 278 /* Get PLL clock source and multiplication factor ----------------------*/
mbed_official 125:23cc3068a9e4 279 pllmull = RCC->CFGR & RCC_CFGR_PLLMULL;
mbed_official 125:23cc3068a9e4 280 pllsource = RCC->CFGR & RCC_CFGR_PLLSRC;
mbed_official 125:23cc3068a9e4 281 pllmull = ( pllmull >> 18) + 2;
mbed_official 125:23cc3068a9e4 282
mbed_official 125:23cc3068a9e4 283 if (pllsource == 0x00)
mbed_official 125:23cc3068a9e4 284 {
mbed_official 125:23cc3068a9e4 285 /* HSI oscillator clock divided by 2 selected as PLL clock entry */
mbed_official 125:23cc3068a9e4 286 SystemCoreClock = (HSI_VALUE >> 1) * pllmull;
mbed_official 125:23cc3068a9e4 287 }
mbed_official 125:23cc3068a9e4 288 else
mbed_official 125:23cc3068a9e4 289 {
mbed_official 125:23cc3068a9e4 290 prediv1factor = (RCC->CFGR2 & RCC_CFGR2_PREDIV1) + 1;
mbed_official 125:23cc3068a9e4 291 /* HSE oscillator clock selected as PREDIV1 clock entry */
mbed_official 125:23cc3068a9e4 292 SystemCoreClock = (HSE_VALUE / prediv1factor) * pllmull;
mbed_official 125:23cc3068a9e4 293 }
mbed_official 125:23cc3068a9e4 294 break;
mbed_official 125:23cc3068a9e4 295 default: /* HSI used as system clock */
mbed_official 125:23cc3068a9e4 296 SystemCoreClock = HSI_VALUE;
mbed_official 125:23cc3068a9e4 297 break;
mbed_official 125:23cc3068a9e4 298 }
mbed_official 125:23cc3068a9e4 299 /* Compute HCLK clock frequency ----------------*/
mbed_official 125:23cc3068a9e4 300 /* Get HCLK prescaler */
mbed_official 125:23cc3068a9e4 301 tmp = AHBPrescTable[((RCC->CFGR & RCC_CFGR_HPRE) >> 4)];
mbed_official 125:23cc3068a9e4 302 /* HCLK clock frequency */
mbed_official 125:23cc3068a9e4 303 SystemCoreClock >>= tmp;
mbed_official 125:23cc3068a9e4 304 }
mbed_official 125:23cc3068a9e4 305
mbed_official 125:23cc3068a9e4 306 /**
mbed_official 125:23cc3068a9e4 307 * @brief Configures the System clock source, PLL Multiplier and Divider factors,
mbed_official 125:23cc3068a9e4 308 * AHB/APBx prescalers and Flash settings
mbed_official 125:23cc3068a9e4 309 * @note This function should be called only once the RCC clock configuration
mbed_official 125:23cc3068a9e4 310 * is reset to the default reset state (done in SystemInit() function).
mbed_official 125:23cc3068a9e4 311 * @param None
mbed_official 125:23cc3068a9e4 312 * @retval None
mbed_official 125:23cc3068a9e4 313 */
mbed_official 125:23cc3068a9e4 314 void SetSysClock(void)
mbed_official 125:23cc3068a9e4 315 {
mbed_official 135:067cc8ba23da 316 /* 1- Try to start with HSE and external clock */
mbed_official 135:067cc8ba23da 317 #if USE_PLL_HSE_EXTC != 0
mbed_official 135:067cc8ba23da 318 if (SetSysClock_PLL_HSE(1) == 0)
mbed_official 135:067cc8ba23da 319 #endif
mbed_official 135:067cc8ba23da 320 {
mbed_official 135:067cc8ba23da 321 /* 2- If fail try to start with HSE and external xtal */
mbed_official 135:067cc8ba23da 322 #if USE_PLL_HSE_XTAL != 0
mbed_official 135:067cc8ba23da 323 if (SetSysClock_PLL_HSE(0) == 0)
mbed_official 135:067cc8ba23da 324 #endif
mbed_official 135:067cc8ba23da 325 {
mbed_official 135:067cc8ba23da 326 /* 3- If fail start with HSI clock */
mbed_official 135:067cc8ba23da 327 if (SetSysClock_PLL_HSI() == 0)
mbed_official 135:067cc8ba23da 328 {
mbed_official 135:067cc8ba23da 329 while(1)
mbed_official 135:067cc8ba23da 330 {
mbed_official 135:067cc8ba23da 331 // [TODO] Put something here to tell the user that a problem occured...
mbed_official 135:067cc8ba23da 332 }
mbed_official 135:067cc8ba23da 333 }
mbed_official 135:067cc8ba23da 334 }
mbed_official 135:067cc8ba23da 335 }
mbed_official 135:067cc8ba23da 336
mbed_official 135:067cc8ba23da 337 /* Output SYSCLK on MCO pin(PA8) for debugging purpose */
mbed_official 135:067cc8ba23da 338 /*
mbed_official 135:067cc8ba23da 339 // Enable GPIOA clock
mbed_official 135:067cc8ba23da 340 RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);
mbed_official 135:067cc8ba23da 341 // Configure MCO pin (PA8)
mbed_official 135:067cc8ba23da 342 GPIO_InitTypeDef GPIO_InitStructure;
mbed_official 135:067cc8ba23da 343 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
mbed_official 135:067cc8ba23da 344 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
mbed_official 135:067cc8ba23da 345 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
mbed_official 135:067cc8ba23da 346 GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
mbed_official 135:067cc8ba23da 347 GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
mbed_official 135:067cc8ba23da 348 GPIO_Init(GPIOA, &GPIO_InitStructure);
mbed_official 135:067cc8ba23da 349 // Select the clock to output
mbed_official 135:067cc8ba23da 350 RCC_MCOConfig(RCC_MCOSource_SYSCLK, RCC_MCOPrescaler_1);
mbed_official 135:067cc8ba23da 351 */
mbed_official 135:067cc8ba23da 352 }
mbed_official 135:067cc8ba23da 353
mbed_official 135:067cc8ba23da 354 #if (USE_PLL_HSE_XTAL != 0) || (USE_PLL_HSE_EXTC != 0)
mbed_official 135:067cc8ba23da 355 /******************************************************************************/
mbed_official 135:067cc8ba23da 356 /* PLL (clocked by HSE) used as System clock source */
mbed_official 135:067cc8ba23da 357 /******************************************************************************/
mbed_official 135:067cc8ba23da 358 uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
mbed_official 135:067cc8ba23da 359 {
mbed_official 135:067cc8ba23da 360 __IO uint32_t StartUpCounter = 0;
mbed_official 135:067cc8ba23da 361 __IO uint32_t HSEStatus = 0;
mbed_official 135:067cc8ba23da 362
mbed_official 135:067cc8ba23da 363 /* Bypass HSE: can be done only if HSE is OFF */
mbed_official 135:067cc8ba23da 364 if (bypass != 0)
mbed_official 135:067cc8ba23da 365 {
mbed_official 135:067cc8ba23da 366 RCC->CR &= ((uint32_t)~RCC_CR_HSEON); /* To be sure HSE is OFF */
mbed_official 135:067cc8ba23da 367 RCC->CR |= ((uint32_t)RCC_CR_HSEBYP);
mbed_official 135:067cc8ba23da 368 }
mbed_official 135:067cc8ba23da 369
mbed_official 135:067cc8ba23da 370 /* Enable HSE */
mbed_official 135:067cc8ba23da 371 RCC->CR |= ((uint32_t)RCC_CR_HSEON);
mbed_official 135:067cc8ba23da 372
mbed_official 135:067cc8ba23da 373 /* Wait till HSE is ready */
mbed_official 135:067cc8ba23da 374 do
mbed_official 135:067cc8ba23da 375 {
mbed_official 135:067cc8ba23da 376 HSEStatus = RCC->CR & RCC_CR_HSERDY;
mbed_official 135:067cc8ba23da 377 StartUpCounter++;
mbed_official 135:067cc8ba23da 378 } while((HSEStatus == 0) && (StartUpCounter != HSE_STARTUP_TIMEOUT));
mbed_official 135:067cc8ba23da 379
mbed_official 135:067cc8ba23da 380 /* Check if HSE has started correctly */
mbed_official 135:067cc8ba23da 381 if ((RCC->CR & RCC_CR_HSERDY) != RESET)
mbed_official 135:067cc8ba23da 382 {
mbed_official 135:067cc8ba23da 383 /* Enable prefetch buffer and set flash latency
mbed_official 135:067cc8ba23da 384 0WS for 0 < SYSCLK <= 24 MHz
mbed_official 135:067cc8ba23da 385 1WS for 24 < SYSCLK <= 48 MHz
mbed_official 135:067cc8ba23da 386 2WS for 48 < SYSCLK <= 72 MHz */
mbed_official 135:067cc8ba23da 387 FLASH->ACR = FLASH_ACR_PRFTBE | (uint32_t)FLASH_ACR_LATENCY_1; /* 2 WS */
mbed_official 135:067cc8ba23da 388
mbed_official 135:067cc8ba23da 389 /* Warning: values are obtained with external xtal or clock = 8 MHz */
mbed_official 135:067cc8ba23da 390 /* SYSCLK = 72 MHz (8 MHz * 9) */
mbed_official 135:067cc8ba23da 391 RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLMULL));
mbed_official 135:067cc8ba23da 392 RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_PREDIV1 | RCC_CFGR_PLLXTPRE_PREDIV1 | RCC_CFGR_PLLMULL9
mbed_official 135:067cc8ba23da 393 | RCC_CFGR_HPRE_DIV1 /* HCLK = 72 MHz */
mbed_official 135:067cc8ba23da 394 | RCC_CFGR_PPRE2_DIV1 /* PCLK2 = 72 MHz */
mbed_official 135:067cc8ba23da 395 | RCC_CFGR_PPRE1_DIV2); /* PCLK1 = 36 MHz */
mbed_official 135:067cc8ba23da 396 /* USBCLK = 48 MHz (72 MHz / 1.5) --> USB OK */
mbed_official 135:067cc8ba23da 397
mbed_official 135:067cc8ba23da 398 /* Enable PLL */
mbed_official 135:067cc8ba23da 399 RCC->CR |= RCC_CR_PLLON;
mbed_official 135:067cc8ba23da 400
mbed_official 135:067cc8ba23da 401 /* Wait till PLL is ready */
mbed_official 135:067cc8ba23da 402 while((RCC->CR & RCC_CR_PLLRDY) == 0)
mbed_official 135:067cc8ba23da 403 {
mbed_official 135:067cc8ba23da 404 }
mbed_official 135:067cc8ba23da 405
mbed_official 135:067cc8ba23da 406 /* Select PLL as system clock source */
mbed_official 135:067cc8ba23da 407 RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
mbed_official 135:067cc8ba23da 408 RCC->CFGR |= (uint32_t)RCC_CFGR_SW_PLL;
mbed_official 135:067cc8ba23da 409
mbed_official 135:067cc8ba23da 410 /* Wait till PLL is used as system clock source */
mbed_official 135:067cc8ba23da 411 while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != (uint32_t)RCC_CFGR_SWS_PLL)
mbed_official 135:067cc8ba23da 412 {
mbed_official 135:067cc8ba23da 413 }
mbed_official 137:f9a97811e98c 414
mbed_official 137:f9a97811e98c 415 SystemCoreClock = 72000000;
mbed_official 135:067cc8ba23da 416 return 1; // OK
mbed_official 135:067cc8ba23da 417 }
mbed_official 135:067cc8ba23da 418 else
mbed_official 135:067cc8ba23da 419 {
mbed_official 135:067cc8ba23da 420 return 0; // FAIL
mbed_official 135:067cc8ba23da 421 }
mbed_official 135:067cc8ba23da 422 }
mbed_official 135:067cc8ba23da 423 #endif
mbed_official 135:067cc8ba23da 424
mbed_official 125:23cc3068a9e4 425 /******************************************************************************/
mbed_official 125:23cc3068a9e4 426 /* PLL (clocked by HSI) used as System clock source */
mbed_official 125:23cc3068a9e4 427 /******************************************************************************/
mbed_official 135:067cc8ba23da 428 uint8_t SetSysClock_PLL_HSI(void)
mbed_official 135:067cc8ba23da 429 {
mbed_official 125:23cc3068a9e4 430 /* At this stage the HSI is already enabled and used as System clock source */
mbed_official 125:23cc3068a9e4 431
mbed_official 135:067cc8ba23da 432 /* Enable prefetch buffer and set flash latency
mbed_official 135:067cc8ba23da 433 0WS for 0 < SYSCLK <= 24 MHz
mbed_official 135:067cc8ba23da 434 1WS for 24 < SYSCLK <= 48 MHz
mbed_official 135:067cc8ba23da 435 2WS for 48 < SYSCLK <= 72 MHz */
mbed_official 135:067cc8ba23da 436 FLASH->ACR = FLASH_ACR_PRFTBE | (uint32_t)FLASH_ACR_LATENCY_1; /* 2 WS */
mbed_official 135:067cc8ba23da 437
mbed_official 135:067cc8ba23da 438 /* SYSCLK = 64 MHz (8 MHz / 2 * 16) */
mbed_official 125:23cc3068a9e4 439 RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_PLLSRC | RCC_CFGR_PLLXTPRE | RCC_CFGR_PLLMULL));
mbed_official 135:067cc8ba23da 440 RCC->CFGR |= (uint32_t)(RCC_CFGR_PLLSRC_HSI_Div2 | RCC_CFGR_PLLXTPRE_PREDIV1 | RCC_CFGR_PLLMULL16
mbed_official 135:067cc8ba23da 441 | RCC_CFGR_HPRE_DIV1 /* HCLK = 64 MHz */
mbed_official 135:067cc8ba23da 442 | RCC_CFGR_PPRE2_DIV1 /* PCLK2 = 64 MHz */
mbed_official 135:067cc8ba23da 443 | RCC_CFGR_PPRE1_DIV2); /* PCLK1 = 32 MHz */
mbed_official 135:067cc8ba23da 444 /* USBCLK = 42.667 MHz (64 MHz / 1.5) --> USB NOT POSSIBLE */
mbed_official 125:23cc3068a9e4 445
mbed_official 125:23cc3068a9e4 446 /* Enable PLL */
mbed_official 125:23cc3068a9e4 447 RCC->CR |= RCC_CR_PLLON;
mbed_official 125:23cc3068a9e4 448
mbed_official 125:23cc3068a9e4 449 /* Wait till PLL is ready */
mbed_official 125:23cc3068a9e4 450 while((RCC->CR & RCC_CR_PLLRDY) == 0)
mbed_official 125:23cc3068a9e4 451 {
mbed_official 125:23cc3068a9e4 452 }
mbed_official 125:23cc3068a9e4 453
mbed_official 125:23cc3068a9e4 454 /* Select PLL as system clock source */
mbed_official 125:23cc3068a9e4 455 RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
mbed_official 125:23cc3068a9e4 456 RCC->CFGR |= (uint32_t)RCC_CFGR_SW_PLL;
mbed_official 125:23cc3068a9e4 457
mbed_official 125:23cc3068a9e4 458 /* Wait till PLL is used as system clock source */
mbed_official 125:23cc3068a9e4 459 while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS) != (uint32_t)RCC_CFGR_SWS_PLL)
mbed_official 125:23cc3068a9e4 460 {
mbed_official 125:23cc3068a9e4 461 }
mbed_official 135:067cc8ba23da 462
mbed_official 137:f9a97811e98c 463 SystemCoreClock = 64000000;
mbed_official 135:067cc8ba23da 464 return 1; // OK
mbed_official 125:23cc3068a9e4 465 }
mbed_official 125:23cc3068a9e4 466
mbed_official 125:23cc3068a9e4 467 /**
mbed_official 125:23cc3068a9e4 468 * @}
mbed_official 125:23cc3068a9e4 469 */
mbed_official 125:23cc3068a9e4 470
mbed_official 125:23cc3068a9e4 471 /**
mbed_official 125:23cc3068a9e4 472 * @}
mbed_official 125:23cc3068a9e4 473 */
mbed_official 125:23cc3068a9e4 474
mbed_official 125:23cc3068a9e4 475 /**
mbed_official 125:23cc3068a9e4 476 * @}
mbed_official 125:23cc3068a9e4 477 */
mbed_official 125:23cc3068a9e4 478
mbed_official 125:23cc3068a9e4 479 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/