stm32 USART的使用源程序

#include "stm32f10x_lib.h"

#include"stdio.h"



void RCC_Configuration(void)

{

ErrorStatus HSEStartUpStatus;

/* RCC system reset(for debug purpose) */

RCC_DeInit();          //将外设RCC 寄存器重设为缺省值

/* 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（AHB时钟） = SYSCLK 设置AHB时钟*/

   RCC_HCLKConfig(RCC_SYSCLK_Div1);//AHB(Advanced High performance Bus)系统总线

                                                    //APB(Advanced Peripheral Bus)外围总线



   /* 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，设置PLL时钟源及倍频系数（<=72M）*/

   RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);



   /* Enable PLL 使能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);

}

}





void USART_configuration(void)

{

   USART_InitTypeDef USART_InitStructure;



   USART_InitStructure.USART_BaudRate = 9600;

   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_Tx | USART_Mode_Rx;





   USART_Init(USART1, &USART_InitStructure);

   USART_Cmd(USART1, ENABLE);





}

void USART_ClockInitconfiguration(void)

{

   USART_ClockInitTypeDef  USART_ClockInitStructuree;

   USART_ClockInitStructuree.USART_Clock = USART_Clock_Disable;

   USART_ClockInitStructuree.USART_CPOL = USART_CPOL_High;

   USART_ClockInitStructuree.USART_CPHA = USART_CPHA_1Edge;

   USART_ClockInitStructuree.USART_LastBit = USART_LastBit_Enable;

   USART_ClockInit(USART1, &USART_ClockInitStructuree);



}



void GPIO_configuration(void)

{

     GPIO_InitTypeDef GPIO_InitStructure;

     RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_USART1  , ENABLE);



    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);



    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;

    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;

    GPIO_Init(GPIOA, &GPIO_InitStructure);

}





int main(void)

{

   unsigned char i,data;



   RCC_Configuration();

   GPIO_configuration();

   USART_ClockInitconfiguration();

   USART_configuration();

   data='A';

   for(i=0;i<30;i++)

   {

USART_SendData(USART1, data);

data++;

while(USART_GetFlagStatus(USART1, USART_FLAG_TC) ==RESET)        ;



}



  return(1);

   }