Mercurial > public > ostc4
annotate Small_CPU/Src/system_stm32f4xx.c @ 203:adc1e7d628be
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author | Ideenmodellierer |
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date | Sat, 23 Mar 2019 21:32:16 +0100 |
parents | f35e53ef04e0 |
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rev | line source |
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38 | 1 /** |
2 ****************************************************************************** | |
3 * @file system_stm32f4xx.c | |
4 * @author MCD Application Team | |
5 * @version V1.1.0 | |
6 * @date 26-June-2014 | |
7 * @brief CMSIS Cortex-M4 Device Peripheral Access Layer System Source File. | |
8 * | |
9 * This file provides two functions and one global variable to be called from | |
10 * user application: | |
11 * - SystemInit(): This function is called at startup just after reset and | |
12 * before branch to main program. This call is made inside | |
13 * the "startup_stm32f4xx.s" file. | |
14 * | |
15 * - SystemCoreClock variable: Contains the core clock (HCLK), it can be used | |
16 * by the user application to setup the SysTick | |
17 * timer or configure other parameters. | |
18 * | |
19 * - SystemCoreClockUpdate(): Updates the variable SystemCoreClock and must | |
20 * be called whenever the core clock is changed | |
21 * during program execution. | |
22 * | |
23 * | |
24 ****************************************************************************** | |
25 * @attention | |
26 * | |
27 * <h2><center>© COPYRIGHT 2014 STMicroelectronics</center></h2> | |
28 * | |
29 * Redistribution and use in source and binary forms, with or without modification, | |
30 * are permitted provided that the following conditions are met: | |
31 * 1. Redistributions of source code must retain the above copyright notice, | |
32 * this list of conditions and the following disclaimer. | |
33 * 2. Redistributions in binary form must reproduce the above copyright notice, | |
34 * this list of conditions and the following disclaimer in the documentation | |
35 * and/or other materials provided with the distribution. | |
36 * 3. Neither the name of STMicroelectronics nor the names of its contributors | |
37 * may be used to endorse or promote products derived from this software | |
38 * without specific prior written permission. | |
39 * | |
40 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
41 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
43 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE | |
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR | |
46 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER | |
47 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, | |
48 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
49 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
50 * | |
51 ****************************************************************************** | |
52 */ | |
53 | |
54 /** @addtogroup CMSIS | |
55 * @{ | |
56 */ | |
57 | |
58 /** @addtogroup stm32f4xx_system | |
59 * @{ | |
60 */ | |
61 | |
62 /** @addtogroup STM32F4xx_System_Private_Includes | |
63 * @{ | |
64 */ | |
65 | |
66 #include <stdint.h> | |
67 | |
68 #include "stm32f4xx_hal.h" | |
69 | |
70 #if !defined (HSE_VALUE) | |
71 #define HSE_VALUE ((uint32_t)8000000) /*!< Default value of the External oscillator in Hz */ | |
72 #endif /* HSE_VALUE */ | |
73 | |
74 #if !defined (HSI_VALUE) | |
75 #define HSI_VALUE ((uint32_t)16000000) /*!< Value of the Internal oscillator in Hz*/ | |
76 #endif /* HSI_VALUE */ | |
77 | |
78 /** | |
79 * @} | |
80 */ | |
81 | |
82 /** @addtogroup STM32F4xx_System_Private_TypesDefinitions | |
83 * @{ | |
84 */ | |
85 | |
86 /** | |
87 * @} | |
88 */ | |
89 | |
90 /** @addtogroup STM32F4xx_System_Private_Defines | |
91 * @{ | |
92 */ | |
93 | |
94 /************************* Miscellaneous Configuration ************************/ | |
95 | |
96 /*!< Uncomment the following line if you need to relocate your vector Table in | |
97 Internal SRAM. */ | |
98 /* #define VECT_TAB_SRAM */ | |
99 #define VECT_TAB_OFFSET 0x00 /*!< Vector Table base offset field. | |
100 This value must be a multiple of 0x200. */ | |
101 /******************************************************************************/ | |
102 | |
103 /** | |
104 * @} | |
105 */ | |
106 | |
107 /** @addtogroup STM32F4xx_System_Private_Macros | |
108 * @{ | |
109 */ | |
110 | |
111 /** | |
112 * @} | |
113 */ | |
114 | |
115 /** @addtogroup STM32F4xx_System_Private_Variables | |
116 * @{ | |
117 */ | |
118 /* This variable is updated in three ways: | |
119 1) by calling CMSIS function SystemCoreClockUpdate() | |
120 2) by calling HAL API function HAL_RCC_GetHCLKFreq() | |
121 3) each time HAL_RCC_ClockConfig() is called to configure the system clock frequency | |
122 Note: If you use this function to configure the system clock; then there | |
123 is no need to call the 2 first functions listed above, since SystemCoreClock | |
124 variable is updated automatically. | |
125 */ | |
131
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126 uint32_t SystemCoreClock = 16000000; |
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127 const uint8_t AHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9}; |
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128 const uint8_t APBPrescTable[8] = {0, 0, 0, 0, 1, 2, 3, 4}; |
38 | 129 /** |
130 * @} | |
131 */ | |
132 | |
133 /** @addtogroup STM32F4xx_System_Private_FunctionPrototypes | |
134 * @{ | |
135 */ | |
136 | |
137 /** | |
138 * @} | |
139 */ | |
140 | |
141 /** @addtogroup STM32F4xx_System_Private_Functions | |
142 * @{ | |
143 */ | |
144 | |
145 /** | |
146 * @brief Setup the microcontroller system | |
147 * Initialize the FPU setting, vector table location and External memory | |
148 * configuration. | |
149 * @param None | |
150 * @retval None | |
151 */ | |
152 void SystemInit(void) | |
153 { | |
154 /* FPU settings ------------------------------------------------------------*/ | |
155 #if (__FPU_PRESENT == 1) && (__FPU_USED == 1) | |
156 SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2)); /* set CP10 and CP11 Full Access */ | |
157 #endif | |
158 /* Reset the RCC clock configuration to the default reset state ------------*/ | |
159 /* Set HSION bit */ | |
160 RCC->CR |= (uint32_t)0x00000001; | |
161 | |
162 /* Reset CFGR register */ | |
163 RCC->CFGR = 0x00000000; | |
164 | |
165 /* Reset HSEON, CSSON and PLLON bits */ | |
166 RCC->CR &= (uint32_t)0xFEF6FFFF; | |
167 | |
168 /* Reset PLLCFGR register */ | |
169 RCC->PLLCFGR = 0x24003010; | |
170 | |
171 /* Reset HSEBYP bit */ | |
172 RCC->CR &= (uint32_t)0xFFFBFFFF; | |
173 | |
174 /* Disable all interrupts */ | |
175 RCC->CIR = 0x00000000; | |
176 | |
177 /* Configure the Vector Table location add offset address ------------------*/ | |
178 #ifdef VECT_TAB_SRAM | |
179 SCB->VTOR = SRAM_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal SRAM */ | |
180 #else | |
181 SCB->VTOR = FLASH_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal FLASH */ | |
182 #endif | |
183 } | |
184 | |
185 /** | |
186 * @brief Update SystemCoreClock variable according to Clock Register Values. | |
187 * The SystemCoreClock variable contains the core clock (HCLK), it can | |
188 * be used by the user application to setup the SysTick timer or configure | |
189 * other parameters. | |
190 * | |
191 * @note Each time the core clock (HCLK) changes, this function must be called | |
192 * to update SystemCoreClock variable value. Otherwise, any configuration | |
193 * based on this variable will be incorrect. | |
194 * | |
195 * @note - The system frequency computed by this function is not the real | |
196 * frequency in the chip. It is calculated based on the predefined | |
197 * constant and the selected clock source: | |
198 * | |
199 * - If SYSCLK source is HSI, SystemCoreClock will contain the HSI_VALUE(*) | |
200 * | |
201 * - If SYSCLK source is HSE, SystemCoreClock will contain the HSE_VALUE(**) | |
202 * | |
203 * - If SYSCLK source is PLL, SystemCoreClock will contain the HSE_VALUE(**) | |
204 * or HSI_VALUE(*) multiplied/divided by the PLL factors. | |
205 * | |
206 * (*) HSI_VALUE is a constant defined in stm32f4xx_hal_conf.h file (default value | |
207 * 16 MHz) but the real value may vary depending on the variations | |
208 * in voltage and temperature. | |
209 * | |
210 * (**) HSE_VALUE is a constant defined in stm32f4xx_hal_conf.h file (its value | |
211 * depends on the application requirements), user has to ensure that HSE_VALUE | |
212 * is same as the real frequency of the crystal used. Otherwise, this function | |
213 * may have wrong result. | |
214 * | |
215 * - The result of this function could be not correct when using fractional | |
216 * value for HSE crystal. | |
217 * | |
218 * @param None | |
219 * @retval None | |
220 */ | |
221 void SystemCoreClockUpdate(void) | |
222 { | |
223 uint32_t tmp = 0, pllvco = 0, pllp = 2, pllsource = 0, pllm = 2; | |
224 | |
225 /* Get SYSCLK source -------------------------------------------------------*/ | |
226 tmp = RCC->CFGR & RCC_CFGR_SWS; | |
227 | |
228 switch (tmp) | |
229 { | |
230 case 0x00: /* HSI used as system clock source */ | |
231 SystemCoreClock = HSI_VALUE; | |
232 break; | |
233 case 0x04: /* HSE used as system clock source */ | |
234 SystemCoreClock = HSE_VALUE; | |
235 break; | |
236 case 0x08: /* PLL used as system clock source */ | |
237 | |
238 /* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLL_M) * PLL_N | |
239 SYSCLK = PLL_VCO / PLL_P | |
240 */ | |
241 pllsource = (RCC->PLLCFGR & RCC_PLLCFGR_PLLSRC) >> 22; | |
242 pllm = RCC->PLLCFGR & RCC_PLLCFGR_PLLM; | |
243 | |
244 if (pllsource != 0) | |
245 { | |
246 /* HSE used as PLL clock source */ | |
247 pllvco = (HSE_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6); | |
248 } | |
249 else | |
250 { | |
251 /* HSI used as PLL clock source */ | |
252 pllvco = (HSI_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6); | |
253 } | |
254 | |
255 pllp = (((RCC->PLLCFGR & RCC_PLLCFGR_PLLP) >>16) + 1 ) *2; | |
256 SystemCoreClock = pllvco/pllp; | |
257 break; | |
258 default: | |
259 SystemCoreClock = HSI_VALUE; | |
260 break; | |
261 } | |
262 /* Compute HCLK frequency --------------------------------------------------*/ | |
263 /* Get HCLK prescaler */ | |
264 tmp = AHBPrescTable[((RCC->CFGR & RCC_CFGR_HPRE) >> 4)]; | |
265 /* HCLK frequency */ | |
266 SystemCoreClock >>= tmp; | |
267 } | |
268 | |
269 /** | |
270 * @} | |
271 */ | |
272 | |
273 /** | |
274 * @} | |
275 */ | |
276 | |
277 /** | |
278 * @} | |
279 */ | |
280 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/ |