main.c

stm32初级例程

/**************************************************************
**  精英STM32开发板
**  版本：V1.0
**  功能：	不断查询串口状态，看串口是否收到数据
			串口1配置如下
			 115200,8,N,1
			本串口程序是接收到什么字符就返回什么字符
			使用我提供的串口调试工具，选择【串口超级终端】波特率设置115200
***************************************************************/

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


/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
GPIO_InitTypeDef GPIO_InitStructure;
ErrorStatus HSEStartUpStatus;

/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void NVIC_Configuration(void);
void GPIO_Configuration(void);
void USART1_InitConfig(uint32 BaudRate);
/* Private functions ---------------------------------------------------------*/

#define TBUF_SIZE   256      /*** Must be a power of 2 (2,4,8,16,32,64,128,256,512,...) ***/
#define RBUF_SIZE   256      /*** Must be a power of 2 (2,4,8,16,32,64,128,256,512,...) ***/

/*----------------------------------------------------------------------------
 *----------------------------------------------------------------------------*/
#if TBUF_SIZE < 2
#error TBUF_SIZE is too small.  It must be larger than 1.
#elif ((TBUF_SIZE & (TBUF_SIZE-1)) != 0)
#error TBUF_SIZE must be a power of 2.
#endif

#if RBUF_SIZE < 2
#error RBUF_SIZE is too small.  It must be larger than 1.
#elif ((RBUF_SIZE & (RBUF_SIZE-1)) != 0)
#error RBUF_SIZE must be a power of 2.
#endif

/*----------------------------------------------------------------------------
 *----------------------------------------------------------------------------*/
//数据缓冲队列
struct buf_st
{
   unsigned int in;// Next In Index    下一个数据输入指针
   unsigned int out;// Next Out Index  下一个数据输出指针
   char buf[RBUF_SIZE];// Buffer  数据缓冲队列
};
//声明1个接收数据缓冲队列
static struct buf_st rbuf =
{
   0, 0, 
};
#define SIO_RBUFLEN ((unsigned short)(rbuf.in - rbuf.out))
//声明1个发送数据缓冲队列
static struct buf_st tbuf =
{
   0, 0, 
};
#define SIO_TBUFLEN ((unsigned short)(tbuf.in - tbuf.out))

static unsigned int tx_restart = 1;               // NZ if TX restart is required

//考虑到效率问题，串口初始化用库函数
//串口收发函数仍然直接操作寄存器
/*----------------------------------------------------------------------------
  USART1_IRQHandler
  Handles USART1 global interrupt request.
    串口中断函数
 *----------------------------------------------------------------------------*/
void USART1_IRQHandler_Fun(void)
{
   volatile unsigned int IIR;
   struct buf_st* p;

   //读取串口状态
   IIR = USART1->SR;
   //串口接收中断
   if (IIR & USART_FLAG_RXNE)
   {
      //必须清除中断标志
      USART1->SR &= ~USART_FLAG_RXNE;            // clear interrupt

      p = &rbuf;
      //接收数据缓冲未满继续放数据进缓冲区
      if (((p->in - p->out) & ~(RBUF_SIZE - 1)) == 0)
      {
         p->buf[p->in & (RBUF_SIZE - 1)] = (USART1->DR & 0x1FF);
         p->in++;
      }
   }
   //串口发送中断
   if (IIR & USART_FLAG_TXE)
   {  
      //必须清除中断标志
      USART1->SR &= ~USART_FLAG_TXE;             // clear interrupt

      p = &tbuf;
      //发送数据缓冲还有数据继续从发送缓冲区取数据
      if (p->in != p->out)
      {
         USART1->DR = (p->buf[p->out & (TBUF_SIZE - 1)] & 0x1FF);
         p->out++;
         tx_restart = 0;
      }
      else//发送数据缓冲空表示数据发送结束
      {
         tx_restart = 1;
         USART1->CR1 &= ~USART_FLAG_TXE;           // disable TX interrupt if nothing to send
      }
   }
}

/*------------------------------------------------------------------------------
  buffer_Init
  initialize the buffers
  初始化接收缓冲、发送缓冲
 *------------------------------------------------------------------------------*/
void buffer_Init(void)
{
   tbuf.in = 0;                                    // Clear com buffer indexes
   tbuf.out = 0;
   tx_restart = 1;

   rbuf.in = 0;
   rbuf.out = 0;
}

/*------------------------------------------------------------------------------
  SenChar
  transmit a character
  发送1个字节数据
 *------------------------------------------------------------------------------*/
int SendChar(int c)
{
   struct buf_st* p = &tbuf;

   // If the buffer is full, return an error value
   //如果发送缓冲满，直接返回
   if (SIO_TBUFLEN >= TBUF_SIZE)
      return (-1);
   //向发送缓冲填充数据
   p->buf[p->in & (TBUF_SIZE - 1)] = c;           // Add data to the transmit buffer.
   p->in++;
   //如果发送中断禁止，那么开启发送中断
   if (tx_restart)
   {
      // If transmit interrupt is disabled, enable it
      tx_restart = 0;
      USART1->CR1 |= USART_FLAG_TXE;                // enable TX interrupt
   }

   return (0);
}

/*------------------------------------------------------------------------------
  GetKey
  receive a character
  接收1个字节
 *------------------------------------------------------------------------------*/
int GetKey(void)
{
   struct buf_st* p = &rbuf;

   if (SIO_RBUFLEN == 0)
      return (-1);

   return (p->buf[(p->out++) & (RBUF_SIZE - 1)]);
}

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

   buffer_Init();//串口收发缓冲初始化
   //配置串口
   USART1_InitConfig(115200);


   printf("Interrupt driven Serial I/O Example\r\n\r\n");

   while (1)
   {
      // Loop forever
      unsigned char c;

      printf("Press a key. ");//提示从串口输入1个字符
      c = getchar();
      printf("\r\n");
      printf("You pressed '%c'.\r\n\r\n", c);
   } // end while
}

//串口初始化函数
void USART1_InitConfig(uint32 BaudRate)
{
   USART_InitTypeDef USART_InitStructure;
   NVIC_InitTypeDef NVIC_InitStructure; 

   //使能串口的RCC时钟
   RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1 | RCC_APB2Periph_GPIOA, ENABLE);

   //串口使用的GPIO口配置
   /* Configure USART1 Rx (PA.10) as input floating */
   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
   GPIO_Init(GPIOA, &GPIO_InitStructure);

   /* Configure USART1 Tx (PA.09) as alternate function push-pull */
   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
   GPIO_Init(GPIOA, &GPIO_InitStructure);

   //配置串口
   USART_InitStructure.USART_BaudRate = BaudRate;
   USART_InitStructure.USART_WordLength = USART_WordLength_8b;
   USART_InitStructure.USART_StopBits = USART_StopBits_1;
   USART_InitStructure.USART_Parity = USART_Parity_No;
   USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
   USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;

   /* Configure USART1 */
   USART_Init(USART1, &USART_InitStructure);//配置串口1

   /* Enable USART1 Receive interrupts 使能串口接收中断*/
   USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
   //串口发送中断在发送数据时开启
   //USART_ITConfig(USART1, USART_IT_TXE, ENABLE);

   /* Enable the USART1 */
   USART_Cmd(USART1, ENABLE);//使能串口1

   //串口中断配置
   /* Configure the NVIC Preemption Priority Bits */  
   NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);

   /* Enable the USART1 Interrupt */
   NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQChannel;
   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-------------------------------------------------------

   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 |
      GPIO_Pin_9 |
      GPIO_Pin_10 |
      GPIO_Pin_11;
   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
   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****/