求助stm32usart程序，麻烦大家帮我分析下问题可能原因

txz · 发表于 2012-4-25 17:37:45

原子哥，我是菜鸟加新手，我弄了一个stm的串口程序，用keil调试时串口数据寄存器值是一直是0，不知道原因，能够帮我看看程序有问题吗
#include "stm32f10x.h"
void RCC_Configuration(void);
void Delay(uint32_t delaytime);
void GPIO_Configuration(void);
void USART_Configuration(void);
int main(void)
{
RCC_Configuration();
GPIO_Configuration();
USART_Configuration();
GPIO_ResetBits(GPIOA,GPIO_Pin_11); //485只发送
while (1)
{
USART_SendData(USART1, (u8) 0xa4);
while(USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET)
{
}
Delay(0xaffff);
}
}

void RCC_Configuration(void)
{
SystemInit();
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_USART1, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
}

void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
/*TX在PA9,配置为推挽*/
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);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11 ;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_Init(GPIOA, &GPIO_InitStructure);

}

void USART_Configuration(void)
{
USART_InitTypeDef USART_InitStructure;

USART_InitStructure.USART_BaudRate = 115200;
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;

USART_Init(USART1,&USART_InitStructure);

USART_Cmd(USART1,ENABLE);
}

void Delay(uint32_t delaytime)
{
for(;delaytime>0;delaytime--);
}