📄 main.c
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/**
******************************************************************************
* @file RCC/main.c
* @author MCD Application Team
* @version V3.0.0
* @date 04/06/2009
* @brief Main program body.
******************************************************************************
* @copy
*
* THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS
* WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE
* TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY
* DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING
* FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE
* CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.
*
* <h2><center>© COPYRIGHT 2009 STMicroelectronics</center></h2>
*/
/* Includes ------------------------------------------------------------------*/
#include "main.h"
/** @addtogroup StdPeriph_Examples
* @{
*/
/** @addtogroup RCC_Example
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
#define DELAY_COUNT 0xFFFFF
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
GPIO_InitTypeDef GPIO_InitStructure;
RCC_ClocksTypeDef RCC_ClockFreq;
ErrorStatus HSEStartUpStatus;
/* Private function prototypes -----------------------------------------------*/
void SetSysClock(void);
void SetSysClockToHSE(void);
void SetSysClockTo20(void);
void SetSysClockTo36(void);
void SetSysClockTo48(void);
void SetSysClockTo72(void);
void NVIC_Configuration(void);
void Delay(__IO uint32_t nCount);
/* Private functions ---------------------------------------------------------*/
/**
* @brief Main program.
* @param None
* @retval : None
*/
int main(void)
{
/* Configure the System clock frequency, HCLK, PCLK2 and PCLK1 prescalers */
SetSysClock();
/* This function fills the RCC_ClockFreq structure with the current
frequencies of different on chip clocks (for debug purpose) */
RCC_GetClocksFreq(&RCC_ClockFreq);
/* Enable Clock Security System(CSS): this will generate an NMI exception
when HSE clock fails */
RCC_ClockSecuritySystemCmd(ENABLE);
/* NVIC configuration ------------------------------------------------------*/
NVIC_Configuration();
/* Enable GPIO_LED and GPIOA clock -----------------------------------------*/
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIO_LED | RCC_APB2Periph_GPIOA, ENABLE);
/* Configure GPIO_LED Pin 6, Pin 7, Pin 8 and Pin 9 as Output push-pull ----*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_Init(GPIO_LED, &GPIO_InitStructure);
/* Turn on Leds connected to GPIO_LED Pin 7 and Pin 9 */
GPIO_Write(GPIO_LED, GPIO_Pin_7 | GPIO_Pin_9);
/* Output HSE clock on MCO pin */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOA, &GPIO_InitStructure);
RCC_MCOConfig(RCC_MCO_HSE);
/* Toggle leds connected to GPIO_LED Pin 6, Pin 7, Pin 8 and Pin 9 pins */
while (1)
{
GPIO_Write(GPIO_LED, (uint16_t)~GPIO_ReadOutputData(GPIO_LED));
/* Insert a delay */
Delay(DELAY_COUNT);
}
}
/**
* @brief Configures the System clock frequency, HCLK, PCLK2 and PCLK1
* prescalers.
* @param None
* @retval : None
*/
void SetSysClock(void)
{
#if defined SYSCLK_HSE
SetSysClockToHSE();
#elif defined SYSCLK_FREQ_20MHz
SetSysClockTo20();
#elif defined SYSCLK_FREQ_36MHz
SetSysClockTo36();
#elif defined SYSCLK_FREQ_48MHz
SetSysClockTo48();
#elif defined SYSCLK_FREQ_72MHz
SetSysClockTo72();
#endif
/* If none of the define above is enabled, the HSI is used as System clock
source (default after reset) */
}
/**
* @brief Selects HSE as System clock source and configure HCLK, PCLK2
* and PCLK1 prescalers.
* @param None
* @retval : None
*/
void SetSysClockToHSE(void)
{
/* SYSCLK, HCLK, PCLK2 and PCLK1 configuration -----------------------------*/
/* RCC system reset(for debug purpose) */
RCC_DeInit();
/* Enable HSE */
RCC_HSEConfig(RCC_HSE_ON);
/* Wait till HSE is ready */
HSEStartUpStatus = RCC_WaitForHSEStartUp();
if (HSEStartUpStatus == SUCCESS)
{
/* Enable Prefetch Buffer */
FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);
/* Flash 0 wait state */
FLASH_SetLatency(FLASH_Latency_0);
/* HCLK = SYSCLK */
RCC_HCLKConfig(RCC_SYSCLK_Div1);
/* PCLK2 = HCLK */
RCC_PCLK2Config(RCC_HCLK_Div1);
/* PCLK1 = HCLK */
RCC_PCLK1Config(RCC_HCLK_Div1);
/* Select HSE as system clock source */
RCC_SYSCLKConfig(RCC_SYSCLKSource_HSE);
/* Wait till PLL is used as system clock source */
while (RCC_GetSYSCLKSource() != 0x04)
{
}
}
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 */
/* Go to infinite loop */
while (1)
{
}
}
}
/**
* @brief Sets System clock frequency to 20MHz and configure HCLK, PCLK2
* and PCLK1 prescalers.
* @param None
* @retval : None
*/
void SetSysClockTo20(void)
{
/* SYSCLK, HCLK, PCLK2 and PCLK1 configuration -----------------------------*/
/* RCC system reset(for debug purpose) */
RCC_DeInit();
/* Enable HSE */
RCC_HSEConfig(RCC_HSE_ON);
/* Wait till HSE is ready */
HSEStartUpStatus = RCC_WaitForHSEStartUp();
if (HSEStartUpStatus == SUCCESS)
{
/* Enable Prefetch Buffer */
FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);
/* Flash 0 wait state */
FLASH_SetLatency(FLASH_Latency_0);
/* HCLK = SYSCLK */
RCC_HCLKConfig(RCC_SYSCLK_Div1);
/* PCLK2 = HCLK */
RCC_PCLK2Config(RCC_HCLK_Div1);
/* PCLK1 = HCLK */
RCC_PCLK1Config(RCC_HCLK_Div1);
/* PLLCLK = (8MHz / 2) * 5 = 20 MHz */
RCC_PLLConfig(RCC_PLLSource_HSE_Div2, RCC_PLLMul_5);
/* Enable PLL */
RCC_PLLCmd(ENABLE);
/* Wait till PLL is ready */
while (RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET)
{
}
/* Select PLL as system clock source */
RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);
/* Wait till PLL is used as system clock source */
while (RCC_GetSYSCLKSource() != 0x08)
{
}
}
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 */
/* Go to infinite loop */
while (1)
{
}
}
}
/**
* @brief Sets System clock frequency to 36MHz and configure HCLK, PCLK2
* and PCLK1 prescalers.
* @param None
* @retval : None
*/
void SetSysClockTo36(void)
{
/* SYSCLK, HCLK, PCLK2 and PCLK1 configuration -----------------------------*/
/* RCC system reset(for debug purpose) */
RCC_DeInit();
/* Enable HSE */
RCC_HSEConfig(RCC_HSE_ON);
/* Wait till HSE is ready */
HSEStartUpStatus = RCC_WaitForHSEStartUp();
if (HSEStartUpStatus == SUCCESS)
{
/* Enable Prefetch Buffer */
FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);
/* Flash 1 wait state */
FLASH_SetLatency(FLASH_Latency_1);
/* HCLK = SYSCLK */
RCC_HCLKConfig(RCC_SYSCLK_Div1);
/* PCLK2 = HCLK */
RCC_PCLK2Config(RCC_HCLK_Div1);
/* PCLK1 = HCLK */
RCC_PCLK1Config(RCC_HCLK_Div1);
/* PLLCLK = (8MHz / 2) * 9 = 36 MHz */
RCC_PLLConfig(RCC_PLLSource_HSE_Div2, RCC_PLLMul_9);
/* Enable PLL */
RCC_PLLCmd(ENABLE);
/* Wait till PLL is ready */
while (RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET)
{
}
/* Select PLL as system clock source */
RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);
/* Wait till PLL is used as system clock source */
while (RCC_GetSYSCLKSource() != 0x08)
{
}
}
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 */
/* Go to infinite loop */
while (1)
{
}
}
}
/**
* @brief Sets System clock frequency to 48MHz and configure HCLK, PCLK2
* and PCLK1 prescalers.
* @param None
* @retval : None
*/
void SetSysClockTo48(void)
{
/* SYSCLK, HCLK, PCLK2 and PCLK1 configuration -----------------------------*/
/* RCC system reset(for debug purpose) */
RCC_DeInit();
/* Enable HSE */
RCC_HSEConfig(RCC_HSE_ON);
/* Wait till HSE is ready */
HSEStartUpStatus = RCC_WaitForHSEStartUp();
if (HSEStartUpStatus == SUCCESS)
{
/* Enable Prefetch Buffer */
FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);
/* Flash 1 wait state */
FLASH_SetLatency(FLASH_Latency_1);
/* HCLK = SYSCLK */
RCC_HCLKConfig(RCC_SYSCLK_Div1);
/* PCLK2 = HCLK */
RCC_PCLK2Config(RCC_HCLK_Div1);
/* PCLK1 = HCLK/2 */
RCC_PCLK1Config(RCC_HCLK_Div2);
/* PLLCLK = 8MHz * 6 = 48 MHz */
RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_6);
/* Enable PLL */
RCC_PLLCmd(ENABLE);
/* Wait till PLL is ready */
while (RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET)
{
}
/* Select PLL as system clock source */
RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);
/* Wait till PLL is used as system clock source */
while (RCC_GetSYSCLKSource() != 0x08)
{
}
}
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 */
/* Go to infinite loop */
while (1)
{
}
}
}
/**
* @brief Sets System clock frequency to 72MHz and configure HCLK, PCLK2
* and PCLK1 prescalers.
* @param None
* @retval : None
*/
void SetSysClockTo72(void)
{
/* SYSCLK, HCLK, PCLK2 and PCLK1 configuration -----------------------------*/
/* RCC system reset(for debug purpose) */
RCC_DeInit();
/* Enable HSE */
RCC_HSEConfig(RCC_HSE_ON);
/* Wait till HSE is ready */
HSEStartUpStatus = RCC_WaitForHSEStartUp();
if (HSEStartUpStatus == SUCCESS)
{
/* Enable Prefetch Buffer */
FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);
/* Flash 2 wait state */
FLASH_SetLatency(FLASH_Latency_2);
/* HCLK = SYSCLK */
RCC_HCLKConfig(RCC_SYSCLK_Div1);
/* PCLK2 = HCLK */
RCC_PCLK2Config(RCC_HCLK_Div1);
/* PCLK1 = HCLK/2 */
RCC_PCLK1Config(RCC_HCLK_Div2);
/* PLLCLK = 8MHz * 9 = 72 MHz */
RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);
/* Enable PLL */
RCC_PLLCmd(ENABLE);
/* Wait till PLL is ready */
while (RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET)
{
}
/* Select PLL as system clock source */
RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);
/* Wait till PLL is used as system clock source */
while(RCC_GetSYSCLKSource() != 0x08)
{
}
}
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 */
/* Go to infinite loop */
while (1)
{
}
}
}
/**
* @brief Configures Vector Table base location.
* @param None
* @retval : None
*/
void NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
/* Enable and configure RCC global IRQ channel */
NVIC_InitStructure.NVIC_IRQChannel = RCC_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
/**
* @brief Inserts a delay time.
* @param nCount: specifies the delay time length.
* @retval : None
*/
void Delay(__IO uint32_t nCount)
{
for(; nCount!= 0;nCount--);
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval : None
*/
void assert_failed(uint8_t* file, uint32_t line)
{
/* User can add his own implementation to report the file name and line number,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* Infinite loop */
while (1)
{
}
}
#endif
/**
* @}
*/
/**
* @}
*/
/******************* (C) COPYRIGHT 2009 STMicroelectronics *****END OF FILE****/
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