main.c

stm32初级例程

/**************************************************************
**  精英STM32开发板
**  版本：V1.0
**  功能：	该例子用RTC产生1秒中断，驱动LED闪烁
			STM32的RTC实际是一个32位的计数器，要得到时分秒信号需要自己转换

***************************************************************/


/* Includes ------------------------------------------------------------------*/
#define SYS_GLOBALS
#include "include.h"

#define  LED_OFF 	GPIO_WriteBit(GPIOC, GPIO_Pin_0, Bit_SET)
#define  LED_ON 	GPIO_WriteBit(GPIOC, GPIO_Pin_0, Bit_RESET)

/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void NVIC_Configuration(void);
void GPIO_Configuration(void);
void RTC_Configuration(void);
/* Private functions ---------------------------------------------------------*/

/*******************************************************************************
RTC_IRQHandler
RTC中断函数
*******************************************************************************/
void RTC_IRQHandler(void)
{
  // 判断是否是RTC秒中断
  if (RTC_GetITStatus(RTC_IT_SEC) != RESET)
  {
    /* Clear the RTC Second interrupt */
    //清除秒中断标志
    RTC_ClearITPendingBit(RTC_IT_SEC);

    /* Toggle GPIO_LED pin 8 each 1s */
    //GPIO状态翻转，循环点亮/熄灭LED
    GPIO_WriteBit(GPIOC, GPIO_Pin_0, (BitAction)(1 - GPIO_ReadOutputDataBit(GPIOC, GPIO_Pin_0)));
    
    /* Wait until last write operation on RTC registers has finished */
    //等待RTC寄存器最后一次写操作已完成
    RTC_WaitForLastTask();
    
    /* Reset RTC Counter when Time is 23:59:59 */
    //秒计数器到23:59:59(86400秒)归0
    if (RTC_GetCounter() == 0x00015180)
    {
       RTC_SetCounter(0x0);
       /* Wait until last write operation on RTC registers has finished */
       //等待RTC寄存器最后一次写操作已完成
       RTC_WaitForLastTask();
    }
  }
}

/*******************************************************************************
* Function Name  : main
* Description    : Main program.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
int main(void)
{
#ifdef DEBUG
  debug();
#endif

  /* System Clocks Configuration */
  RCC_Configuration();//配置系统时钟   

  GPIO_Configuration();//配置GPIO
  
  /* NVIC configuration */
  NVIC_Configuration();//配置中断
  
  //RTC配置
  RTC_Configuration();	   

  

  while (1)
  {                                     // Loop forever
    ;
  } // end while
  
}

//RTC初始化
void RTC_Configuration(void)
{
 NVIC_InitTypeDef NVIC_InitStructure;

  //开启GPIO时钟
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC , ENABLE);

  /* Enable PWR and BKP clocks */
  //允许RTC使用到的PWR,BKP时钟
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR | RCC_APB1Periph_BKP, ENABLE);
  
  /* Allow access to BKP Domain */
  //允许修改备份寄存器
  PWR_BackupAccessCmd(ENABLE);

  /* Reset Backup Domain */
  //复位备份域
  BKP_DeInit();

  /* Enable LSE */
  //使能外部LSE(32768)时钟
  RCC_LSEConfig(RCC_LSE_ON);
  /* Wait till LSE is ready */
  //等待LSE(32768)时钟稳定
  while(RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET)
  {
  }

  /* Select LSE as RTC Clock Source */
  //选择LSE(32768)做RTC时钟源
  RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);

  /* Enable RTC Clock */
  //使能RTC
  RCC_RTCCLKCmd(ENABLE);

  /* Wait for RTC registers synchronization */
  //等待RTC寄存器同步
  RTC_WaitForSynchro();

  /* Wait until last write operation on RTC registers has finished */
  //等待RTC寄存器最后一次写操作已完成
  RTC_WaitForLastTask();
  
  /* Enable the RTC Second */
  //使能RTC秒信号中断发生
  RTC_ITConfig(RTC_IT_SEC, ENABLE);

  /* Wait until last write operation on RTC registers has finished */
  //等待RTC寄存器最后一次写操作已完成
  RTC_WaitForLastTask();
  
  /* Set RTC prescaler: set RTC period to 1sec */
  //设置RTC分频
  RTC_SetPrescaler(32767); /* RTC period = RTCCLK/RTC_PR = (32.768 KHz)/(32767+1) */
  
  /* Wait until last write operation on RTC registers has finished */
  //等待RTC寄存器最后一次写操作已完成
  RTC_WaitForLastTask();

  //RTC中断配置
  /* Configure one bit for preemption priority */
  NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
  
  /* Enable the RTC Interrupt */
  //配置RTC中断
  NVIC_InitStructure.NVIC_IRQChannel = RTC_IRQChannel;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
}

/*******************************************************************************
* Function Name  : RCC_Configuration
* Description    : Configures the different system clocks.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void RCC_Configuration(void)
{ErrorStatus HSEStartUpStatus;   
  
  /* RCC system reset(for debug purpose) */
  RCC_DeInit();

  /* Enable HSE */
  RCC_HSEConfig(RCC_HSE_ON);//使能外部时钟 

  /* Wait till HSE is ready */
  HSEStartUpStatus = RCC_WaitForHSEStartUp();//等待外部时钟就绪

  if(HSEStartUpStatus == SUCCESS)
  {
    /* Enable Prefetch Buffer 启用预取缓冲器 */
    FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);

    /* Flash 2 wait state FLASH设置2个等待周期*/
    FLASH_SetLatency(FLASH_Latency_2);
 
    /* HCLK = SYSCLK 设置系统设置*/
    RCC_HCLKConfig(RCC_SYSCLK_Div1); 
  
    /* PCLK2 = HCLK PCLK2时钟=主时钟*/
    RCC_PCLK2Config(RCC_HCLK_Div1); 

    /* PCLK1 = HCLK/2 PCLK1时钟为主时钟1/2*/
    RCC_PCLK1Config(RCC_HCLK_Div2);

    /* PLLCLK = 8MHz * 9 = 72 MHz 设置时钟为72M*/
    RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);

    /* Enable PLL 使能PLL*/ 
    RCC_PLLCmd(ENABLE);

    /* Wait till PLL is ready 等待PLL工作稳定*/
    while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET)
    {
    }

    /* Select PLL as system clock source 选择PLL做为系统时钟源*/
    RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);

    /* Wait till PLL is used as system clock source 准备就绪，开始干活*/
    while(RCC_GetSYSCLKSource() != 0x08)
    {
    }
  }
}

/*******************************************************************************
* Function Name  : GPIO_Configuration
* Description    : Configures the different GPIO ports.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void GPIO_Configuration(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
  
  /* Enable GPIO_LED clock */
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);//使能GPIO时钟
  //LED_init-------------------------------------------------------
  ////配置管脚
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;//最大输出速度为50MHz
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;////通用推挽输出
  GPIO_Init(GPIOC, &GPIO_InitStructure);			 //设置GPIO为输出
  
}
/*******************************************************************************
* Function Name  : NVIC_Configuration
* Description    : Configures Vector Table base location.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void NVIC_Configuration(void)
{

//#ifdef  VECT_TAB_RAM
#if defined (VECT_TAB_RAM)
  /* Set the Vector Table base location at 0x20000000 */ 
  NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0); //设置中断向量在RAM中
//#elif defined(VECT_TAB_FLASH_IAP)
//  NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x2000);
#else  /* VECT_TAB_FLASH  */
  /* Set the Vector Table base location at 0x08000000 */ 
  NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0); //设置中断向量在FLASH中  
#endif


}




#ifdef  DEBUG
/*******************************************************************************
* Function Name  : assert_failed
* Description    : Reports the name of the source file and the source line number
*                  where the assert_param error has occurred.
* Input          : - file: pointer to the source file name
*                  - line: assert_param error line source number
* Output         : None
* Return         : None
*******************************************************************************/
void assert_failed(u8* file, u32 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 2008 STMicroelectronics *****END OF FILE****/