2019年08月29日 | STM32F429 >> 6. RCC-使用HSE, HSI 配置时钟

本工程板级支持包文件适用于野火stm32f429 开发板。

编程要点

开启HSE/HSI，并等待HSE/HSI 稳定

设置AHB, APB2, APB1 的预分频因子

设置PLL 的时钟来源，设置VCO 输入时钟分频因子PLL_M，设置VCO 输出时钟倍频因子PLL_N，设置PLLCLK 时钟分频因子PLL_P，设置OTGFS, SDIO, RNG 时钟分频因子PLL_Q

开启PLL，并等待PLL 稳定

把PLLCLK 切换为系统时钟SYSCLK

读取时钟切换状态位，确保PLLCLK 被选为系统时钟

bsp_clk.c

/**

  ******************************************************************************

  * @file    bsp_clk.c

  * @author  Waao

  * @version V1.0.0

  * @date    21-Dec-2018

  * @brief   This file contains some board support package's functions for the CLK.

  *            

  ******************************************************************************

  * @attention

  *

  * None

*

  ******************************************************************************

  */

#include

/**

  * @brief  Initialize the SYSCLK powered by HSE

  * @note   None

  * @param  m: VOC input clock's frequency division factor.  

* n: VOC output clock's frequency doubling factor.

* p: PLLCLK clock's frequency division factor.

* q: OTG, FS, SDIO and RNG clock's frequency division factor.

  * @retval None

  */

void HSE_SetSysClock(uint32_t m, uint32_t n, uint32_t p, uint32_t q)

{

__IO uint32_t HSEStartUpStatus = 0;

//Enable the HSE, open the external crystal oscillator

RCC_HSEConfig(RCC_HSE_ON);

//Waiting the HSE to be stable

HSEStartUpStatus = RCC_WaitForHSEStartUp();

if(HSEStartUpStatus == SUCCESS)

{

RCC->APB1ENR |= RCC_APB1ENR_PWREN;

PWR->CR |= PWR_CR_VOS;

//HCLK = SYSCLK / 1

RCC_HCLKConfig(RCC_SYSCLK_Div1);

//PCLK2 = HCLK / 2

RCC_PCLK2Config(RCC_HCLK_Div2);

//PCLK1 = HCLK / 4

RCC_PCLK1Config(RCC_HCLK_Div4);

//Configure the PLL

RCC_PLLConfig(RCC_PLLSource_HSE, m, n, p, q);

//Enable the PLL

RCC_PLLCmd(ENABLE);

//Waiting the PLL to be stable

while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET)

{

}

/*--------------------------------------------*/

//Open the OVER-RIDE mode to reach a higher frequency

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 the FLASH

FLASH->ACR = FLASH_ACR_PRFTEN

|FLASH_ACR_ICEN

|FLASH_ACR_DCEN

|FLASH_ACR_LATENCY_5WS;

/*---------------------------------------------*/

//Change the clock of the PLL to SYSCLK when PLL to be stable

RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);

while(RCC_GetSYSCLKSource() != 0x08)

{

}

}

else

{

while(1)

{

}

}

}

/**

  * @brief  Initialize the SYSCLK powered by HSI

  * @note   None

  * @param  m: VOC input clock's frequency division factor.  

* n: VOC output clock's frequency doubling factor.

* p: PLLCLK clock's frequency division factor.

* q: OTG, FS, SDIO and RNG clock's frequency division factor.

  * @retval None

  */

void HSI_SetSysClock(uint32_t m, uint32_t n, uint32_t p, uint32_t q)

{

__IO uint32_t HSIStartUpStatus = 0;

//Initialize the RCC parameter to reset status

RCC_DeInit();

//Enable the HSI, HSI=16M

RCC_HSICmd(ENABLE);

//Waiting the HSI to be ready

HSIStartUpStatus = RCC->CR & RCC_CR_HSIRDY;

//Continue to run only when the HSI to be ready

if(HSIStartUpStatus == RCC_CR_HSIRDY)

{

RCC->APB1ENR |= RCC_APB1ENR_PWREN;

PWR->CR |= PWR_CR_VOS;

//HCLK = SYSCLK / 1

RCC_HCLKConfig(RCC_SYSCLK_Div1);

//PCLK2 = HCLK / 2

RCC_PCLK2Config(RCC_HCLK_Div2);

//PCLK1 = HCLK / 4

RCC_PCLK1Config(RCC_HCLK_Div4);

//Configure the PLL

RCC_PLLConfig(RCC_PLLSource_HSI, m, n, p, q);

//Enable the PLL

RCC_PLLCmd(ENABLE);

//Waiting the PLL to be stable

while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET)

{

}

/*--------------------------------------------*/

//Open the OVER-RIDE mode to reach a higher frequency

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 the FLASH

FLASH->ACR = FLASH_ACR_PRFTEN

|FLASH_ACR_ICEN

|FLASH_ACR_DCEN

|FLASH_ACR_LATENCY_5WS;

/*---------------------------------------------*/

//Change the clock of the PLL to SYSCLK when PLL to be stable

RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);

while(RCC_GetSYSCLKSource() != 0x08)

{

}

}

else

{

while(1)

{

}

}

}

/**

  * @brief  Configure the MCO1 output the clock signal

  * @note   None

  * @param  None  

  * @retval None

  */

void MCO1_GPIO_Config(void)

{

GPIO_InitTypeDef GPIO_InitStructure;

RCC_AHB1PeriphClockCmd(MCO1_CLK_PORT, ENABLE);

GPIO_InitStructure.GPIO_Pin = MCO1_PIN;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

GPIO_Init(MCO1_PORT, &GPIO_InitStructure);

}

/**

  * @brief  Configure the MCO2 output the clock signal

  * @note   None

  * @param  None  

  * @retval None

  */

void MCO2_GPIO_Config(void)

{

GPIO_InitTypeDef GPIO_InitStructure;

RCC_AHB1PeriphClockCmd(MCO2_CLK_PORT, ENABLE);

GPIO_InitStructure.GPIO_Pin = MCO2_PIN;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;

GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;

GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;

GPIO_Init(MCO2_PORT, &GPIO_InitStructure);

}

bsp_clk.h

/**

  ******************************************************************************

  * @file    bsp_clk.h

  * @author  Waao

  * @version V1.0.0

  * @date    21-Dec-2018

  * @brief   This file contains some board support package's definition for the CLK.

  *            

  ******************************************************************************

  * @attention

  *

  * None

*

  ******************************************************************************

  */

#ifndef __BSP_LED_H_

#define __BSP_LED_H_

#include

#define PLL_M 25

#define PLL_N 360

#define PLL_P 2

#define PLL_Q 7

#define MCO1_PIN       GPIO_Pin_8

#define MCO1_PORT      GPIOA

#define MCO1_CLK_PORT  RCC_AHB1Periph_GPIOA

#define MCO2_PIN       GPIO_Pin_9

#define MCO2_PORT      GPIOC

#define MCO2_CLK_PORT  RCC_AHB1Periph_GPIOC

void HSE_SetSysClock(uint32_t m, uint32_t n, uint32_t p, uint32_t q);

void HSI_SetSysClock(uint32_t m, uint32_t n, uint32_t p, uint32_t q);

void MCO1_GPIO_Config(void);

void MCO2_GPIO_Config(void);

#endif