mbed library sources: Modified to operate FRDM-KL25Z at 48MHz from internal 32kHz oscillator (nothing else changed).
Fork of mbed-src by
The only file that changed is: mbed-src-FLL48/targets/cmsis/TARGET_Freescale/TARGET_KL25Z/system_MKL25Z4.h
Diff: targets/cmsis/TARGET_STM/TARGET_STM32F4XX/system_stm32f4xx.c
- Revision:
- 20:4263a77256ae
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/targets/cmsis/TARGET_STM/TARGET_STM32F4XX/system_stm32f4xx.c Tue Sep 10 15:14:19 2013 +0300 @@ -0,0 +1,573 @@ +/** + ****************************************************************************** + * @file system_stm32f4xx.c + * @author MCD Application Team + * @version V1.1.0 + * @date 11-January-2013 + * @brief CMSIS Cortex-M4 Device Peripheral Access Layer System Source File. + * This file contains the system clock configuration for STM32F4xx devices, + * and is generated by the clock configuration tool + * stm32f4xx_Clock_Configuration_V1.1.0.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_stm32f4xx.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_stm32f4xx.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 "stm32f4xx.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 STM32F40xx/41xx/427x/437x devices + *----------------------------------------------------------------------------- + * System Clock source | PLL (HSE) + *----------------------------------------------------------------------------- + * SYSCLK(Hz) | 168000000 + *----------------------------------------------------------------------------- + * HCLK(Hz) | 168000000 + *----------------------------------------------------------------------------- + * AHB Prescaler | 1 + *----------------------------------------------------------------------------- + * APB1 Prescaler | 4 + *----------------------------------------------------------------------------- + * APB2 Prescaler | 2 + *----------------------------------------------------------------------------- + * HSE Frequency(Hz) | 8000000 + *----------------------------------------------------------------------------- + * PLL_M | 8 + *----------------------------------------------------------------------------- + * PLL_N | 336 + *----------------------------------------------------------------------------- + * PLL_P | 2 + *----------------------------------------------------------------------------- + * PLL_Q | 7 + *----------------------------------------------------------------------------- + * PLLI2S_N | 271 + *----------------------------------------------------------------------------- + * PLLI2S_R | 2 + *----------------------------------------------------------------------------- + * I2S input clock | NA + *----------------------------------------------------------------------------- + * VDD(V) | 3.3 + *----------------------------------------------------------------------------- + * Main regulator output voltage | Scale1 mode + *----------------------------------------------------------------------------- + * Flash Latency(WS) | 5 + *----------------------------------------------------------------------------- + * Prefetch Buffer | ON + *----------------------------------------------------------------------------- + * Instruction cache | ON + *----------------------------------------------------------------------------- + * Data cache | ON + *----------------------------------------------------------------------------- + * Require 48MHz for USB OTG FS, | Disabled + * SDIO and RNG clock | + *----------------------------------------------------------------------------- + *============================================================================= + ****************************************************************************** + * @attention + * + * <h2><center>© COPYRIGHT 2013 STMicroelectronics</center></h2> + * + * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License"); + * You may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.st.com/software_license_agreement_liberty_v2 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + ****************************************************************************** + */ + +/** @addtogroup CMSIS + * @{ + */ + +/** @addtogroup stm32f4xx_system + * @{ + */ + +/** @addtogroup STM32F4xx_System_Private_Includes + * @{ + */ + +#include "stm32f4xx.h" + +/** + * @} + */ + +/** @addtogroup STM32F4xx_System_Private_TypesDefinitions + * @{ + */ + +/** + * @} + */ + +/** @addtogroup STM32F4xx_System_Private_Defines + * @{ + */ + +/************************* Miscellaneous Configuration ************************/ +/*!< Uncomment the following line if you need to use external SRAM mounted + on STM324xG_EVAL/STM324x7I_EVAL boards 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 Parameters *************************************/ +/* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLL_M) * PLL_N */ +#define PLL_M 8 +#define PLL_N 336 + +/* SYSCLK = PLL_VCO / PLL_P */ +#define PLL_P 2 + +/* USB OTG FS, SDIO and RNG Clock = PLL_VCO / PLLQ */ +#define PLL_Q 7 + +#define PLLI2S_N 271 +#define PLLI2S_R 2 + +/******************************************************************************/ + +/** + * @} + */ + +/** @addtogroup STM32F4xx_System_Private_Macros + * @{ + */ + +/** + * @} + */ + +/** @addtogroup STM32F4xx_System_Private_Variables + * @{ + */ + + uint32_t SystemCoreClock = 168000000; + + __I uint8_t AHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9}; + +/** + * @} + */ + +/** @addtogroup STM32F4xx_System_Private_FunctionPrototypes + * @{ + */ + +static void SetSysClock(void); +#ifdef DATA_IN_ExtSRAM + static void SystemInit_ExtMemCtl(void); +#endif /* DATA_IN_ExtSRAM */ + +/** + * @} + */ + +/** @addtogroup STM32F4xx_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 = 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 stm32f4xx.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 stm32f4xx.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) + { + /* Select regulator voltage output Scale 1 mode, System frequency up to 168 MHz */ + RCC->APB1ENR |= RCC_APB1ENR_PWREN; + PWR->CR |= PWR_CR_VOS; + + /* 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 the I2S PLL */ + RCC->PLLI2SCFGR = (PLLI2S_N << 6) | (PLLI2S_R << 28); + + /* Enable the I2S PLL */ + RCC->CR |= RCC_CR_PLLI2SON; + + /* Wait until the I2S PLL is ready */ + while (!(RCC->CR & RCC_CR_PLLI2SRDY)); + + /* Configure Flash prefetch, Instruction cache, Data cache and wait state */ + FLASH->ACR = FLASH_ACR_PRFTEN |FLASH_ACR_ICEN |FLASH_ACR_DCEN |FLASH_ACR_LATENCY_5WS; + + /* 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_stm32f4xx.s + * before jump to __main + * @param None + * @retval None + */ +#ifdef DATA_IN_ExtSRAM +/** + * @brief Setup the external memory controller. + * Called in startup_stm32f4xx.s before jump to main. + * This function configures the external SRAM mounted on STM324xG_EVAL/STM324x7I boards + * 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 | PE2 <-> FSMC_A23 | PF2 <-> FSMC_A2 | PG2 <-> FSMC_A12 | + | PD5 <-> FSMC_NWE | PE3 <-> FSMC_A19 | PF3 <-> FSMC_A3 | PG3 <-> FSMC_A13 | + | PD8 <-> FSMC_D13 | PE4 <-> FSMC_A20 | PF4 <-> FSMC_A4 | PG4 <-> FSMC_A14 | + | PD9 <-> FSMC_D14 | PE5 <-> FSMC_A21 | PF5 <-> FSMC_A5 | PG5 <-> FSMC_A15 | + | PD10 <-> FSMC_D15 | PE6 <-> FSMC_A22 | PF12 <-> FSMC_A6 | PG9 <-> FSMC_NE2 | + | PD11 <-> FSMC_A16 | PE7 <-> FSMC_D4 | PF13 <-> FSMC_A7 |------------------+ + | PD12 <-> FSMC_A17 | PE8 <-> FSMC_D5 | PF14 <-> FSMC_A8 | + | PD13 <-> FSMC_A18 | PE9 <-> FSMC_D6 | PF15 <-> FSMC_A9 | + | PD14 <-> FSMC_D0 | PE10 <-> FSMC_D7 |------------------+ + | PD15 <-> FSMC_D1 | PE11 <-> FSMC_D8 | + +-------------------| PE12 <-> FSMC_D9 | + | PE13 <-> FSMC_D10 | + | PE14 <-> FSMC_D11 | + | 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] = 0xcccccccc; + /* Configure PDx pins in Alternate function mode */ + GPIOD->MODER = 0xaaaa0a0a; + /* Configure PDx pins speed to 100 MHz */ + GPIOD->OSPEEDR = 0xffff0f0f; + /* 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] = 0xcccccccc; + GPIOE->AFR[1] = 0xcccccccc; + /* Configure PEx pins in Alternate function mode */ + GPIOE->MODER = 0xaaaaaaaa; + /* Configure PEx pins speed to 100 MHz */ + GPIOE->OSPEEDR = 0xffffffff; + /* 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] = 0x00001011; + FSMC_Bank1->BTCR[3] = 0x00000201; + FSMC_Bank1E->BWTR[2] = 0x0fffffff; +/* + Bank1_SRAM2 is configured as follow: + + p.FSMC_AddressSetupTime = 1; + p.FSMC_AddressHoldTime = 0; + p.FSMC_DataSetupTime = 2; + p.FSMC_BusTurnAroundDuration = 0; + 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_SRAM; + 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 STMicroelectronics *****END OF FILE****/ +