2 ******************************************************************************
3 * @file system_stm32f4xx.c
4 * @author MCD Application Team
6 * @date 19-September-2011
7 * @brief CMSIS Cortex-M4 Device Peripheral Access Layer System Source File.
8 * This file contains the system clock configuration for STM32F4xx devices,
9 * and is generated by the clock configuration tool
10 * stm32f4xx_Clock_Configuration_V1.0.0.xls
12 * 1. This file provides two functions and one global variable to be called from
14 * - SystemInit(): Setups the system clock (System clock source, PLL Multiplier
15 * and Divider factors, AHB/APBx prescalers and Flash settings),
16 * depending on the configuration made in the clock xls tool.
17 * This function is called at startup just after reset and
18 * before branch to main program. This call is made inside
19 * the "startup_stm32f4xx.s" file.
21 * - SystemCoreClock variable: Contains the core clock (HCLK), it can be used
22 * by the user application to setup the SysTick
23 * timer or configure other parameters.
25 * - SystemCoreClockUpdate(): Updates the variable SystemCoreClock and must
26 * be called whenever the core clock is changed
27 * during program execution.
29 * 2. After each device reset the HSI (16 MHz) is used as system clock source.
30 * Then SystemInit() function is called, in "startup_stm32f4xx.s" file, to
31 * configure the system clock before to branch to main program.
33 * 3. If the system clock source selected by user fails to startup, the SystemInit()
34 * function will do nothing and HSI still used as system clock source. User can
35 * add some code to deal with this issue inside the SetSysClock() function.
37 * 4. The default value of HSE crystal is set to 8 MHz, refer to "HSE_VALUE" define
38 * in "stm32f4xx.h" file. When HSE is used as system clock source, directly or
39 * through PLL, and you are using different crystal you have to adapt the HSE
40 * value to your own configuration.
42 * 5. This file configures the system clock as follows:
43 *=============================================================================
44 *=============================================================================
45 * Supported STM32F4xx device revision | Rev A
46 *-----------------------------------------------------------------------------
47 * System Clock source | PLL (HSE)
48 *-----------------------------------------------------------------------------
49 * SYSCLK(Hz) | 168000000
50 *-----------------------------------------------------------------------------
51 * HCLK(Hz) | 168000000
52 *-----------------------------------------------------------------------------
54 *-----------------------------------------------------------------------------
56 *-----------------------------------------------------------------------------
58 *-----------------------------------------------------------------------------
59 * HSE Frequency(Hz) | 8000000
60 *-----------------------------------------------------------------------------
62 *-----------------------------------------------------------------------------
64 *-----------------------------------------------------------------------------
66 *-----------------------------------------------------------------------------
68 *-----------------------------------------------------------------------------
70 *-----------------------------------------------------------------------------
72 *-----------------------------------------------------------------------------
73 * I2S input clock(Hz) | 38400000
74 *-----------------------------------------------------------------------------
76 *-----------------------------------------------------------------------------
77 * High Performance mode | Enabled
78 *-----------------------------------------------------------------------------
79 * Flash Latency(WS) | 5
80 *-----------------------------------------------------------------------------
81 * Prefetch Buffer | OFF
82 *-----------------------------------------------------------------------------
83 * Instruction cache | ON
84 *-----------------------------------------------------------------------------
86 *-----------------------------------------------------------------------------
87 * Require 48MHz for USB OTG FS, | Enabled
88 * SDIO and RNG clock |
89 *-----------------------------------------------------------------------------
90 *=============================================================================
91 ******************************************************************************
94 * THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
95 * WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
96 * TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
97 * DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
98 * FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
99 * CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
101 * <h2><center>© COPYRIGHT 2011 STMicroelectronics</center></h2>
102 ******************************************************************************
105 /** @addtogroup CMSIS
109 /** @addtogroup stm32f4xx_system
113 /** @addtogroup STM32F4xx_System_Private_Includes
117 #include "stm32f4xx.h"
123 /** @addtogroup STM32F4xx_System_Private_TypesDefinitions
131 /** @addtogroup STM32F4xx_System_Private_Defines
135 /*!< Uncomment the following line if you need to use external SRAM mounted
136 on STM324xG_EVAL board as data memory */
137 /* #define DATA_IN_ExtSRAM */
139 /*!< Uncomment the following line if you need to relocate your vector Table in
141 /* #define VECT_TAB_SRAM */
142 #define VECT_TAB_OFFSET 0x00 /*!< Vector Table base offset field.
143 This value must be a multiple of 0x200. */
146 /* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLL_M) * PLL_N */
150 /* SYSCLK = PLL_VCO / PLL_P */
153 /* USB OTG FS, SDIO and RNG Clock = PLL_VCO / PLLQ */
156 /* PLLI2S_VCO = (HSE_VALUE Or HSI_VALUE / PLL_M) * PLLI2S_N
157 I2SCLK = PLLI2S_VCO / PLLI2S_R */
165 /** @addtogroup STM32F4xx_System_Private_Macros
173 /** @addtogroup STM32F4xx_System_Private_Variables
177 uint32_t SystemCoreClock = 168000000;
179 __I uint8_t AHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9};
185 /** @addtogroup STM32F4xx_System_Private_FunctionPrototypes
189 static void SetSysClock(void);
190 #ifdef DATA_IN_ExtSRAM
191 static void SystemInit_ExtMemCtl(void);
192 #endif /* DATA_IN_ExtSRAM */
198 /** @addtogroup STM32F4xx_System_Private_Functions
203 * @brief Setup the microcontroller system
204 * Initialize the Embedded Flash Interface, the PLL and update the
205 * SystemFrequency variable.
209 void SystemInit(void)
211 /* Reset the RCC clock configuration to the default reset state ------------*/
213 RCC->CR |= (uint32_t)0x00000001;
215 /* Reset CFGR register */
216 RCC->CFGR = 0x00000000;
218 /* Reset HSEON, CSSON and PLLON bits */
219 RCC->CR &= (uint32_t)0xFEF6FFFF;
221 /* Reset PLLCFGR register */
222 RCC->PLLCFGR = 0x24003010;
224 /* Reset HSEBYP bit */
225 RCC->CR &= (uint32_t)0xFFFBFFFF;
227 /* Disable all interrupts */
228 RCC->CIR = 0x00000000;
230 #ifdef DATA_IN_ExtSRAM
231 SystemInit_ExtMemCtl();
232 #endif /* DATA_IN_ExtSRAM */
234 /* Configure the System clock source, PLL Multiplier and Divider factors,
235 AHB/APBx prescalers and Flash settings ----------------------------------*/
238 /* Configure the Vector Table location add offset address ------------------*/
240 SCB->VTOR = SRAM_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal SRAM */
242 SCB->VTOR = FLASH_BASE | VECT_TAB_OFFSET; /* Vector Table Relocation in Internal FLASH */
247 * @brief Update SystemCoreClock variable according to Clock Register Values.
248 * The SystemCoreClock variable contains the core clock (HCLK), it can
249 * be used by the user application to setup the SysTick timer or configure
252 * @note Each time the core clock (HCLK) changes, this function must be called
253 * to update SystemCoreClock variable value. Otherwise, any configuration
254 * based on this variable will be incorrect.
256 * @note - The system frequency computed by this function is not the real
257 * frequency in the chip. It is calculated based on the predefined
258 * constant and the selected clock source:
260 * - If SYSCLK source is HSI, SystemCoreClock will contain the HSI_VALUE(*)
262 * - If SYSCLK source is HSE, SystemCoreClock will contain the HSE_VALUE(**)
264 * - If SYSCLK source is PLL, SystemCoreClock will contain the HSE_VALUE(**)
265 * or HSI_VALUE(*) multiplied/divided by the PLL factors.
267 * (*) HSI_VALUE is a constant defined in stm32f4xx.h file (default value
268 * 16 MHz) but the real value may vary depending on the variations
269 * in voltage and temperature.
271 * (**) HSE_VALUE is a constant defined in stm32f4xx.h file (default value
272 * 25 MHz), user has to ensure that HSE_VALUE is same as the real
273 * frequency of the crystal used. Otherwise, this function may
276 * - The result of this function could be not correct when using fractional
277 * value for HSE crystal.
282 void SystemCoreClockUpdate(void)
284 uint32_t tmp = 0, pllvco = 0, pllp = 2, pllsource = 0, pllm = 2;
286 /* Get SYSCLK source -------------------------------------------------------*/
287 tmp = RCC->CFGR & RCC_CFGR_SWS;
291 case 0x00: /* HSI used as system clock source */
292 SystemCoreClock = HSI_VALUE;
294 case 0x04: /* HSE used as system clock source */
295 SystemCoreClock = HSE_VALUE;
297 case 0x08: /* PLL used as system clock source */
299 /* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLL_M) * PLL_N
300 SYSCLK = PLL_VCO / PLL_P
302 pllsource = (RCC->PLLCFGR & RCC_PLLCFGR_PLLSRC) >> 22;
303 pllm = RCC->PLLCFGR & RCC_PLLCFGR_PLLM;
307 /* HSE used as PLL clock source */
308 pllvco = (HSE_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6);
312 /* HSI used as PLL clock source */
313 pllvco = (HSI_VALUE / pllm) * ((RCC->PLLCFGR & RCC_PLLCFGR_PLLN) >> 6);
316 pllp = (((RCC->PLLCFGR & RCC_PLLCFGR_PLLP) >>16) + 1 ) *2;
317 SystemCoreClock = pllvco/pllp;
320 SystemCoreClock = HSI_VALUE;
323 /* Compute HCLK frequency --------------------------------------------------*/
324 /* Get HCLK prescaler */
325 tmp = AHBPrescTable[((RCC->CFGR & RCC_CFGR_HPRE) >> 4)];
327 SystemCoreClock >>= tmp;
331 * @brief Configures the System clock source, PLL Multiplier and Divider factors,
332 * AHB/APBx prescalers and Flash settings
333 * @Note This function should be called only once the RCC clock configuration
334 * is reset to the default reset state (done in SystemInit() function).
338 static void SetSysClock(void)
340 /******************************************************************************/
341 /* PLL (clocked by HSE) used as System clock source */
342 /******************************************************************************/
343 __IO uint32_t StartUpCounter = 0, HSEStatus = 0;
346 RCC->CR |= ((uint32_t)RCC_CR_HSEON);
348 /* Wait till HSE is ready and if Time out is reached exit */
351 HSEStatus = RCC->CR & RCC_CR_HSERDY;
353 } while((HSEStatus == 0) && (StartUpCounter != HSE_STARTUP_TIMEOUT));
355 if ((RCC->CR & RCC_CR_HSERDY) != RESET)
357 HSEStatus = (uint32_t)0x01;
361 HSEStatus = (uint32_t)0x00;
364 if (HSEStatus == (uint32_t)0x01)
366 /* Enable high performance mode, System frequency up to 168 MHz */
367 RCC->APB1ENR |= RCC_APB1ENR_PWREN;
368 PWR->CR |= PWR_CR_PMODE;
370 /* HCLK = SYSCLK / 1*/
371 RCC->CFGR |= RCC_CFGR_HPRE_DIV1;
373 /* PCLK2 = HCLK / 2*/
374 RCC->CFGR |= RCC_CFGR_PPRE2_DIV2;
376 /* PCLK1 = HCLK / 4*/
377 RCC->CFGR |= RCC_CFGR_PPRE1_DIV4;
379 /* Configure the main PLL */
380 RCC->PLLCFGR = PLL_M | (PLL_N << 6) | (((PLL_P >> 1) -1) << 16) |
381 (RCC_PLLCFGR_PLLSRC_HSE) | (PLL_Q << 24);
383 /* Enable the main PLL */
384 RCC->CR |= RCC_CR_PLLON;
386 /* Wait till the main PLL is ready */
387 while((RCC->CR & RCC_CR_PLLRDY) == 0)
391 /* Configure Flash prefetch, Instruction cache, Data cache and wait state */
392 FLASH->ACR = FLASH_ACR_ICEN |FLASH_ACR_DCEN |FLASH_ACR_LATENCY_5WS;
394 /* Select the main PLL as system clock source */
395 RCC->CFGR &= (uint32_t)((uint32_t)~(RCC_CFGR_SW));
396 RCC->CFGR |= RCC_CFGR_SW_PLL;
398 /* Wait till the main PLL is used as system clock source */
399 while ((RCC->CFGR & (uint32_t)RCC_CFGR_SWS ) != RCC_CFGR_SWS_PLL);
404 { /* If HSE fails to start-up, the application will have wrong clock
405 configuration. User can add here some code to deal with this error */
408 /******************************************************************************/
409 /* I2S clock configuration */
410 /******************************************************************************/
411 /* PLLI2S clock used as I2S clock source */
412 RCC->CFGR &= ~RCC_CFGR_I2SSRC;
414 /* Configure PLLI2S */
415 RCC->PLLI2SCFGR = (PLLI2S_N << 6) | (PLLI2S_R << 28);
418 RCC->CR |= ((uint32_t)RCC_CR_PLLI2SON);
420 /* Wait till PLLI2S is ready */
421 while((RCC->CR & RCC_CR_PLLI2SRDY) == 0)
427 * @brief Setup the external memory controller. Called in startup_stm32f4xx.s
428 * before jump to __main
432 #ifdef DATA_IN_ExtSRAM
434 * @brief Setup the external memory controller.
435 * Called in startup_stm32f4xx.s before jump to main.
436 * This function configures the external SRAM mounted on STM324xG_EVAL board
437 * This SRAM will be used as program data memory (including heap and stack).
441 void SystemInit_ExtMemCtl(void)
443 /*-- GPIOs Configuration -----------------------------------------------------*/
445 +-------------------+--------------------+------------------+------------------+
446 + SRAM pins assignment +
447 +-------------------+--------------------+------------------+------------------+
448 | PD0 <-> FSMC_D2 | PE0 <-> FSMC_NBL0 | PF0 <-> FSMC_A0 | PG0 <-> FSMC_A10 |
449 | PD1 <-> FSMC_D3 | PE1 <-> FSMC_NBL1 | PF1 <-> FSMC_A1 | PG1 <-> FSMC_A11 |
450 | PD4 <-> FSMC_NOE | PE3 <-> FSMC_A19 | PF2 <-> FSMC_A2 | PG2 <-> FSMC_A12 |
451 | PD5 <-> FSMC_NWE | PE4 <-> FSMC_A20 | PF3 <-> FSMC_A3 | PG3 <-> FSMC_A13 |
452 | PD8 <-> FSMC_D13 | PE7 <-> FSMC_D4 | PF4 <-> FSMC_A4 | PG4 <-> FSMC_A14 |
453 | PD9 <-> FSMC_D14 | PE8 <-> FSMC_D5 | PF5 <-> FSMC_A5 | PG5 <-> FSMC_A15 |
454 | PD10 <-> FSMC_D15 | PE9 <-> FSMC_D6 | PF12 <-> FSMC_A6 | PG9 <-> FSMC_NE2 |
455 | PD11 <-> FSMC_A16 | PE10 <-> FSMC_D7 | PF13 <-> FSMC_A7 |------------------+
456 | PD12 <-> FSMC_A17 | PE11 <-> FSMC_D8 | PF14 <-> FSMC_A8 |
457 | PD13 <-> FSMC_A18 | PE12 <-> FSMC_D9 | PF15 <-> FSMC_A9 |
458 | PD14 <-> FSMC_D0 | PE13 <-> FSMC_D10 |------------------+
459 | PD15 <-> FSMC_D1 | PE14 <-> FSMC_D11 |
460 | | PE15 <-> FSMC_D12 |
461 +-------------------+--------------------+
463 /* Enable GPIOD, GPIOE, GPIOF and GPIOG interface clock */
464 RCC->AHB1ENR = 0x00000078;
466 /* Connect PDx pins to FSMC Alternate function */
467 GPIOD->AFR[0] = 0x00cc00cc;
468 GPIOD->AFR[1] = 0xcc0ccccc;
469 /* Configure PDx pins in Alternate function mode */
470 GPIOD->MODER = 0xaaaa0a0a;
471 /* Configure PDx pins speed to 100 MHz */
472 GPIOD->OSPEEDR = 0xffff0f0f;
473 /* Configure PDx pins Output type to push-pull */
474 GPIOD->OTYPER = 0x00000000;
475 /* No pull-up, pull-down for PDx pins */
476 GPIOD->PUPDR = 0x00000000;
478 /* Connect PEx pins to FSMC Alternate function */
479 GPIOE->AFR[0] = 0xc00cc0cc;
480 GPIOE->AFR[1] = 0xcccccccc;
481 /* Configure PEx pins in Alternate function mode */
482 GPIOE->MODER = 0xaaaa828a;
483 /* Configure PEx pins speed to 100 MHz */
484 GPIOE->OSPEEDR = 0xffffc3cf;
485 /* Configure PEx pins Output type to push-pull */
486 GPIOE->OTYPER = 0x00000000;
487 /* No pull-up, pull-down for PEx pins */
488 GPIOE->PUPDR = 0x00000000;
490 /* Connect PFx pins to FSMC Alternate function */
491 GPIOF->AFR[0] = 0x00cccccc;
492 GPIOF->AFR[1] = 0xcccc0000;
493 /* Configure PFx pins in Alternate function mode */
494 GPIOF->MODER = 0xaa000aaa;
495 /* Configure PFx pins speed to 100 MHz */
496 GPIOF->OSPEEDR = 0xff000fff;
497 /* Configure PFx pins Output type to push-pull */
498 GPIOF->OTYPER = 0x00000000;
499 /* No pull-up, pull-down for PFx pins */
500 GPIOF->PUPDR = 0x00000000;
502 /* Connect PGx pins to FSMC Alternate function */
503 GPIOG->AFR[0] = 0x00cccccc;
504 GPIOG->AFR[1] = 0x000000c0;
505 /* Configure PGx pins in Alternate function mode */
506 GPIOG->MODER = 0x00080aaa;
507 /* Configure PGx pins speed to 100 MHz */
508 GPIOG->OSPEEDR = 0x000c0fff;
509 /* Configure PGx pins Output type to push-pull */
510 GPIOG->OTYPER = 0x00000000;
511 /* No pull-up, pull-down for PGx pins */
512 GPIOG->PUPDR = 0x00000000;
514 /*-- FSMC Configuration ------------------------------------------------------*/
515 /* Enable the FSMC interface clock */
516 RCC->AHB3ENR = 0x00000001;
518 /* Configure and enable Bank1_SRAM2 */
519 FSMC_Bank1->BTCR[2] = 0x00001015;
520 FSMC_Bank1->BTCR[3] = 0x00010603;//0x00010400;
521 FSMC_Bank1E->BWTR[2] = 0x0fffffff;
523 Bank1_SRAM2 is configured as follow:
525 p.FSMC_AddressSetupTime = 3;//0;
526 p.FSMC_AddressHoldTime = 0;
527 p.FSMC_DataSetupTime = 6;//4;
528 p.FSMC_BusTurnAroundDuration = 1;
529 p.FSMC_CLKDivision = 0;
530 p.FSMC_DataLatency = 0;
531 p.FSMC_AccessMode = FSMC_AccessMode_A;
533 FSMC_NORSRAMInitStructure.FSMC_Bank = FSMC_Bank1_NORSRAM2;
534 FSMC_NORSRAMInitStructure.FSMC_DataAddressMux = FSMC_DataAddressMux_Disable;
535 FSMC_NORSRAMInitStructure.FSMC_MemoryType = FSMC_MemoryType_PSRAM;
536 FSMC_NORSRAMInitStructure.FSMC_MemoryDataWidth = FSMC_MemoryDataWidth_16b;
537 FSMC_NORSRAMInitStructure.FSMC_BurstAccessMode = FSMC_BurstAccessMode_Disable;
538 FSMC_NORSRAMInitStructure.FSMC_AsynchronousWait = FSMC_AsynchronousWait_Disable;
539 FSMC_NORSRAMInitStructure.FSMC_WaitSignalPolarity = FSMC_WaitSignalPolarity_Low;
540 FSMC_NORSRAMInitStructure.FSMC_WrapMode = FSMC_WrapMode_Disable;
541 FSMC_NORSRAMInitStructure.FSMC_WaitSignalActive = FSMC_WaitSignalActive_BeforeWaitState;
542 FSMC_NORSRAMInitStructure.FSMC_WriteOperation = FSMC_WriteOperation_Enable;
543 FSMC_NORSRAMInitStructure.FSMC_WaitSignal = FSMC_WaitSignal_Disable;
544 FSMC_NORSRAMInitStructure.FSMC_ExtendedMode = FSMC_ExtendedMode_Disable;
545 FSMC_NORSRAMInitStructure.FSMC_WriteBurst = FSMC_WriteBurst_Disable;
546 FSMC_NORSRAMInitStructure.FSMC_ReadWriteTimingStruct = &p;
547 FSMC_NORSRAMInitStructure.FSMC_WriteTimingStruct = &p;
551 #endif /* DATA_IN_ExtSRAM */
565 /******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/