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566 lines
24 KiB
566 lines
24 KiB
10 months ago
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/**
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******************************************************************************
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* @file system_stm32f4xx.c
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* @author MCD Application Team
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* @version V1.3.0
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* @date 08-November-2013
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* @brief CMSIS Cortex-M4 Device Peripheral Access Layer System Source File.
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* This file contains the system clock configuration for STM32F4xx devices.
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*
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* 1. This file provides two functions and one global variable to be called from
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* user application:
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* - SystemInit(): Setups the system clock (System clock source, PLL Multiplier
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* and Divider factors, AHB/APBx prescalers and Flash settings),
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* depending on the configuration made in the clock xls tool.
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* This function is called at startup just after reset and
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* before branch to main program. This call is made inside
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* the "startup_stm32f4xx.s" file.
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*
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* - SystemCoreClock variable: Contains the core clock (HCLK), it can be used
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* by the user application to setup the SysTick
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* timer or configure other parameters.
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*
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* - SystemCoreClockUpdate(): Updates the variable SystemCoreClock and must
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* be called whenever the core clock is changed
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* during program execution.
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*
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* 2. After each device reset the HSI (16 MHz) is used as system clock source.
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* Then SystemInit() function is called, in "startup_stm32f4xx.s" file, to
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* configure the system clock before to branch to main program.
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*
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* 3. If the system clock source selected by user fails to startup, the SystemInit()
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* function will do nothing and HSI still used as system clock source. User can
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* add some code to deal with this issue inside the SetSysClock() function.
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*
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* 4. The default value of HSE crystal is set to 25MHz, refer to "HSE_VALUE" define
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* in "stm32f4xx.h" file. When HSE is used as system clock source, directly or
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* through PLL, and you are using different crystal you have to adapt the HSE
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* value to your own configuration.
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*
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* 5. This file configures the system clock as follows:
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*=============================================================================
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*=============================================================================
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* Supported STM32F40xxx/41xxx devices
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*-----------------------------------------------------------------------------
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* System Clock source | PLL (HSE)
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*-----------------------------------------------------------------------------
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* SYSCLK(Hz) | 168000000
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*-----------------------------------------------------------------------------
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* HCLK(Hz) | 168000000
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*-----------------------------------------------------------------------------
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* AHB Prescaler | 1
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*-----------------------------------------------------------------------------
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* APB1 Prescaler | 4
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*-----------------------------------------------------------------------------
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* APB2 Prescaler | 2
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*-----------------------------------------------------------------------------
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* HSE Frequency(Hz) | 25000000
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*-----------------------------------------------------------------------------
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* PLL_M | 25
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*-----------------------------------------------------------------------------
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* PLL_N | 336
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*-----------------------------------------------------------------------------
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* PLL_P | 2
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*-----------------------------------------------------------------------------
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* PLL_Q | 7
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*-----------------------------------------------------------------------------
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* PLLI2S_N | NA
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*-----------------------------------------------------------------------------
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* PLLI2S_R | NA
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*-----------------------------------------------------------------------------
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* I2S input clock | NA
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*-----------------------------------------------------------------------------
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* VDD(V) | 3.3
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*-----------------------------------------------------------------------------
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* Main regulator output voltage | Scale1 mode
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*-----------------------------------------------------------------------------
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* Flash Latency(WS) | 5
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*-----------------------------------------------------------------------------
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* Prefetch Buffer | ON
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*-----------------------------------------------------------------------------
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* Instruction cache | ON
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*-----------------------------------------------------------------------------
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* Data cache | ON
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*-----------------------------------------------------------------------------
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* Require 48MHz for USB OTG FS, | Disabled
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* SDIO and RNG clock |
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*-----------------------------------------------------------------------------
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*=============================================================================
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*=============================================================================
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* Supported STM32F42xxx/43xxx devices
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*-----------------------------------------------------------------------------
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* System Clock source | PLL (HSE)
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*-----------------------------------------------------------------------------
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* SYSCLK(Hz) | 180000000
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*-----------------------------------------------------------------------------
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* HCLK(Hz) | 180000000
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*-----------------------------------------------------------------------------
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* AHB Prescaler | 1
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*-----------------------------------------------------------------------------
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* APB1 Prescaler | 4
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*-----------------------------------------------------------------------------
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* APB2 Prescaler | 2
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*-----------------------------------------------------------------------------
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* HSE Frequency(Hz) | 25000000
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*-----------------------------------------------------------------------------
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* PLL_M | 25
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*-----------------------------------------------------------------------------
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* PLL_N | 360
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*-----------------------------------------------------------------------------
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* PLL_P | 2
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*-----------------------------------------------------------------------------
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* PLL_Q | 7
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*-----------------------------------------------------------------------------
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* PLLI2S_N | NA
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*-----------------------------------------------------------------------------
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* PLLI2S_R | NA
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*-----------------------------------------------------------------------------
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* I2S input clock | NA
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*-----------------------------------------------------------------------------
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* VDD(V) | 3.3
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*-----------------------------------------------------------------------------
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* Main regulator output voltage | Scale1 mode
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*-----------------------------------------------------------------------------
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* Flash Latency(WS) | 5
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*-----------------------------------------------------------------------------
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* Prefetch Buffer | ON
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*-----------------------------------------------------------------------------
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* Instruction cache | ON
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*-----------------------------------------------------------------------------
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* Data cache | ON
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*-----------------------------------------------------------------------------
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* Require 48MHz for USB OTG FS, | Disabled
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* SDIO and RNG clock |
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*-----------------------------------------------------------------------------
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*=============================================================================
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*=============================================================================
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* Supported STM32F401xx devices
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*-----------------------------------------------------------------------------
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* System Clock source | PLL (HSE)
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*-----------------------------------------------------------------------------
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* SYSCLK(Hz) | 84000000
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*-----------------------------------------------------------------------------
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* HCLK(Hz) | 84000000
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*-----------------------------------------------------------------------------
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* AHB Prescaler | 1
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*-----------------------------------------------------------------------------
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* APB1 Prescaler | 2
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*-----------------------------------------------------------------------------
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* APB2 Prescaler | 1
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*-----------------------------------------------------------------------------
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* HSE Frequency(Hz) | 25000000
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*-----------------------------------------------------------------------------
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* PLL_M | 25
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*-----------------------------------------------------------------------------
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* PLL_N | 336
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*-----------------------------------------------------------------------------
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* PLL_P | 4
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*-----------------------------------------------------------------------------
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* PLL_Q | 7
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*-----------------------------------------------------------------------------
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* PLLI2S_N | NA
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*-----------------------------------------------------------------------------
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* PLLI2S_R | NA
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*-----------------------------------------------------------------------------
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* I2S input clock | NA
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*-----------------------------------------------------------------------------
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* VDD(V) | 3.3
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*-----------------------------------------------------------------------------
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* Main regulator output voltage | Scale1 mode
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*-----------------------------------------------------------------------------
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* Flash Latency(WS) | 2
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*-----------------------------------------------------------------------------
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* Prefetch Buffer | ON
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*-----------------------------------------------------------------------------
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* Instruction cache | ON
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*-----------------------------------------------------------------------------
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* Data cache | ON
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*-----------------------------------------------------------------------------
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* Require 48MHz for USB OTG FS, | Disabled
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* SDIO and RNG clock |
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*-----------------------------------------------------------------------------
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*=============================================================================
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******************************************************************************
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* @attention
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*
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* <h2><center>© COPYRIGHT 2013 STMicroelectronics</center></h2>
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*
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* Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
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* You may not use this file except in compliance with the License.
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* You may obtain a copy of the License at:
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*
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* http://www.st.com/software_license_agreement_liberty_v2
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*
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******************************************************************************
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*/
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/** @addtogroup CMSIS
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* @{
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*/
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/** @addtogroup stm32f4xx_system
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* @{
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*/
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/** @addtogroup STM32F4xx_System_Private_Includes
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* @{
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*/
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#include "stm32f4xx.h"
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/**
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* @}
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*/
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/** @addtogroup STM32F4xx_System_Private_TypesDefinitions
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* @{
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*/
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/**
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* @}
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*/
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/** @addtogroup STM32F4xx_System_Private_Defines
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* @{
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*/
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/************************* Miscellaneous Configuration ************************/
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/*!< Uncomment the following line if you need to use external SRAM or SDRAM mounted
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on STM324xG_EVAL/STM324x7I_EVAL/STM324x9I_EVAL boards as data memory */
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#if defined (STM32F40_41xxx) || defined (STM32F427_437xx) || defined (STM32F429_439xx)
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/* #define DATA_IN_ExtSRAM */
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#endif /* STM32F40_41xxx || STM32F427_437x || STM32F429_439xx */
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#if defined (STM32F427_437xx) || defined (STM32F429_439xx)
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/* #define DATA_IN_ExtSDRAM */
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#endif /* STM32F427_437x || STM32F429_439xx */
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/*!< Uncomment the following line if you need to relocate your vector Table in
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Internal SRAM. */
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/* #define VECT_TAB_SRAM */
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#define VECT_TAB_OFFSET 0x00 /*!< Vector Table base offset field.
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This value must be a multiple of 0x200. */
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/******************************************************************************/
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/************************* PLL Parameters *************************************/
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/* PLL_VCO = (HSE_VALUE or HSI_VALUE / PLL_M) * PLL_N */
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#define PLL_M 12
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/* USB OTG FS, SDIO and RNG Clock = PLL_VCO / PLLQ */
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#define PLL_Q 7
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#if defined (STM32F40_41xxx)
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#define PLL_N 336
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/* SYSCLK = PLL_VCO / PLL_P */
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#define PLL_P 2
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#endif /* STM32F40_41xxx */
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#if defined (STM32F427_437xx) || defined (STM32F429_439xx)
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#define PLL_N 360
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/* SYSCLK = PLL_VCO / PLL_P */
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#define PLL_P 2
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#endif /* STM32F427_437x || STM32F429_439xx */
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#if defined (STM32F401xx)
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#define PLL_N 336
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/* SYSCLK = PLL_VCO / PLL_P */
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#define PLL_P 4
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#endif /* STM32F401xx */
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/******************************************************************************/
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/**
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* @}
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*/
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/** @addtogroup STM32F4xx_System_Private_Macros
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* @{
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*/
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/**
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* @}
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*/
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/** @addtogroup STM32F4xx_System_Private_Variables
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* @{
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*/
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#if defined (STM32F40_41xxx)
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uint32_t SystemCoreClock = 168000000;
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#endif /* STM32F40_41xxx */
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#if defined (STM32F427_437xx) || defined (STM32F429_439xx)
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uint32_t SystemCoreClock = 180000000;
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#endif /* STM32F427_437x || STM32F429_439xx */
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#if defined (STM32F401xx)
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uint32_t SystemCoreClock = 84000000;
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#endif /* STM32F401xx */
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__I uint8_t AHBPrescTable[16] = {0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9};
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/**
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* @}
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*/
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/** @addtogroup STM32F4xx_System_Private_FunctionPrototypes
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* @{
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*/
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static void SetSysClock(void);
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#if defined (DATA_IN_ExtSRAM) || defined (DATA_IN_ExtSDRAM)
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static void SystemInit_ExtMemCtl(void);
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#endif /* DATA_IN_ExtSRAM || DATA_IN_ExtSDRAM */
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/**
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* @}
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*/
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/** @addtogroup STM32F4xx_System_Private_Functions
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||
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* @{
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||
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*/
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/**
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* @brief Setup the microcontroller system
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* Initialize the Embedded Flash Interface, the PLL and update the
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* SystemFrequency variable.
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* @param None
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* @retval None
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*/
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void SystemInit(void)
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{
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/* FPU settings ------------------------------------------------------------*/
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#if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
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SCB->CPACR |= ((3UL << 10*2)|(3UL << 11*2)); /* set CP10 and CP11 Full Access */
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#endif
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/* Reset the RCC clock configuration to the default reset state ------------*/
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/* Set HSION bit */
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RCC->CR |= (uint32_t)0x00000001;
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/* Reset CFGR register */
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RCC->CFGR = 0x00000000;
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/* Reset HSEON, CSSON and PLLON bits */
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RCC->CR &= (uint32_t)0xFEF6FFFF;
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/* Reset PLLCFGR register */
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RCC->PLLCFGR = 0x24003010;
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/* Reset HSEBYP bit */
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RCC->CR &= (uint32_t)0xFFFBFFFF;
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/* Disable all interrupts */
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RCC->CIR = 0x00000000;
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/* Configure the System clock source, PLL Multiplier and Divider factors,
|
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AHB/APBx prescalers and Flash settings ----------------------------------*/
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SetSysClock();
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|
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||
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/* Configure the Vector Table location add offset address ------------------*/
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||
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//SCB->VTOR = FLASH_BASE | VECT_TAB_OFFSET; // Vector Table Relocation in Internal FLASH
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||
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}
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||
|
|
||
|
/**
|
||
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* @brief Update SystemCoreClock variable according to Clock Register Values.
|
||
|
* The SystemCoreClock variable contains the core clock (HCLK), it can
|
||
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* 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
|
||
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* based on this variable will be incorrect.
|
||
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*
|
||
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* @note - The system frequency computed by this function is not the real
|
||
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* frequency in the chip. It is calculated based on the predefined
|
||
|
* constant and the selected clock source:
|
||
|
*
|
||
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* - If SYSCLK source is HSI, SystemCoreClock will contain the HSI_VALUE(*)
|
||
|
*
|
||
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* - If SYSCLK source is HSE, SystemCoreClock will contain the HSE_VALUE(**)
|
||
|
*
|
||
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* - If SYSCLK source is PLL, SystemCoreClock will contain the HSE_VALUE(**)
|
||
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* or HSI_VALUE(*) multiplied/divided by the PLL factors.
|
||
|
*
|
||
|
* (*) HSI_VALUE is a constant defined in stm32f4xx.h file (default value
|
||
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* 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 -------------------------------------------------------*/
|
||
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tmp = RCC->CFGR & RCC_CFGR_SWS;
|
||
|
|
||
|
switch (tmp)
|
||
|
{
|
||
|
case 0x00: /* HSI used as system clock source */
|
||
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SystemCoreClock = HSI_VALUE;
|
||
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break;
|
||
|
case 0x04: /* HSE used as system clock source */
|
||
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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 */
|
||
|
RCC->APB1ENR |= RCC_APB1ENR_PWREN;
|
||
|
PWR->CR |= PWR_CR_VOS;
|
||
|
|
||
|
/* HCLK = SYSCLK / 1*/
|
||
|
RCC->CFGR |= RCC_CFGR_HPRE_DIV1;
|
||
|
|
||
|
#if defined (STM32F40_41xxx) || defined (STM32F427_437xx) || defined (STM32F429_439xx)
|
||
|
/* PCLK2 = HCLK / 2*/
|
||
|
RCC->CFGR |= RCC_CFGR_PPRE2_DIV2;
|
||
|
|
||
|
/* PCLK1 = HCLK / 4*/
|
||
|
RCC->CFGR |= RCC_CFGR_PPRE1_DIV4;
|
||
|
#endif /* STM32F40_41xxx || STM32F427_437x || STM32F429_439xx */
|
||
|
|
||
|
#if defined (STM32F401xx)
|
||
|
/* PCLK2 = HCLK / 2*/
|
||
|
RCC->CFGR |= RCC_CFGR_PPRE2_DIV1;
|
||
|
|
||
|
/* PCLK1 = HCLK / 4*/
|
||
|
RCC->CFGR |= RCC_CFGR_PPRE1_DIV2;
|
||
|
#endif /* STM32F401xx */
|
||
|
|
||
|
/* 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)
|
||
|
{
|
||
|
}
|
||
|
|
||
|
#if defined (STM32F427_437xx) || defined (STM32F429_439xx)
|
||
|
/* Enable the Over-drive to extend the clock frequency to 180 Mhz */
|
||
|
PWR->CR |= PWR_CR_ODEN;
|
||
|
while((PWR->CSR & PWR_CSR_ODRDY) == 0)
|
||
|
{
|
||
|
}
|
||
|
PWR->CR |= PWR_CR_ODSWEN;
|
||
|
while((PWR->CSR & PWR_CSR_ODSWRDY) == 0)
|
||
|
{
|
||
|
}
|
||
|
/* 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;
|
||
|
#endif /* STM32F427_437x || STM32F429_439xx */
|
||
|
|
||
|
#if defined (STM32F40_41xxx)
|
||
|
/* 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;
|
||
|
#endif /* STM32F40_41xxx */
|
||
|
|
||
|
#if defined (STM32F401xx)
|
||
|
/* Configure Flash prefetch, Instruction cache, Data cache and wait state */
|
||
|
FLASH->ACR = FLASH_ACR_PRFTEN | FLASH_ACR_ICEN |FLASH_ACR_DCEN |FLASH_ACR_LATENCY_2WS;
|
||
|
#endif /* STM32F401xx */
|
||
|
|
||
|
/* 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 */
|
||
|
}
|
||
|
|
||
|
}
|
||
|
|
||
|
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
|