在keil上串口实现printf遇到的问题

问题是这样的，当我不对rcc初始化，只开启RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);串口能打印，但是我对rcc初始化后，keil上的USART窗口打印什么都没打印。还有另一个问题，打印ABCD。的那个循环在串口上只能打印出ACD。就是别的都能打印就是第二个字符打印不了
#include "stm32f10x.h"
#include "stdio.h"
/*************************************************************
                                                                                        ?aoˉêy°?
*************************************************************/                                                                                       
void USART_Configuration(void);
void GPIO_Configuration(void);
void RCC_Configuration(void);
//?óêüêy?Y
int fputc(int ch,FILE *f)
{
        USART_SendData(USART1,(u8) ch);
        while(USART_GetFlagStatus(USART1, USART_FLAG_TC)==RESET);
        return ch;
}
//·￠?íêy?Y
int GetKey(void)
{
        while (USART_GetFlagStatus(USART1, USART_FLAG_RXNE)==SET);
      return ((int) USART_ReceiveData(USART1));
}
int main(void)
{
        u8 i,data = 'A';
        RCC_Configuration();
        USART_Configuration();
        GPIO_Configuration();
        RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA, ENABLE);
        for(i=0; i<20; i++)
        {
                USART_SendData(USART1,data);
                data++;               
                while(USART_GetFlagStatus(USART1, USART_FLAG_TC)==RESET);
                USART_ClearFlag(USART1,USART_FLAG_TC);
        }
        printf("\n\thello world！");
        //add your code here
        return 0;
}
void USART_Configuration(void)
{
        USART_InitTypeDef USART_InitStructure;
        USART_ClockInitTypeDef USART_ClockInitStructure;
        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_ClockInitStructure.USART_Clock = USART_Clock_Disable;
        USART_ClockInitStructure.USART_CPOL = USART_CPOL_High;
        USART_ClockInitStructure.USART_CPHA = USART_CPHA_1Edge;
        USART_ClockInitStructure.USART_LastBit = USART_LastBit_Enable;
        USART_Init(USART1, &USART_InitStructure);       
        USART_Cmd(USART1,ENABLE);
}
void GPIO_Configuration(void)
{
        GPIO_InitTypeDef GPIO_InitStructure;
        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //GPIO?ú×÷?a?′ó?1|?üê?3?ê±￡????ü?′ó?í?íìê?3?
        GPIO_Init(GPIOA, &GPIO_InitStructure);
        GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10; //×??′ó?1|?üê?è?ê±￡?2??ü?a?￡?aê?è?￡????ò?′ó?ê±???ü????ê?è?
        GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; //?aà?????????ê?è?
        GPIO_Init(GPIOA, &GPIO_InitStructure);
}
void RCC_Configuration(void)
{
        ErrorStatus HSEStartUpStatus;
        FlagStatus Status;
        RCC_DeInit();//è±ê?
        RCC_HSEConfig(RCC_HSE_ON);//????ía2????ùê±?ó
        HSEStartUpStatus = RCC_WaitForHSEStartUp();
        while(HSEStartUpStatus ！= SUCCESS);//μè′yHSE?è?¨
       
        RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_9);//éè??HSE9±??μ
        RCC_PLLCmd(ENABLE);//ê1?ü?a??PLL
        Status = RCC_GetFlagStatus(RCC_FLAG_PLLRDY);
        while(Status == RESET);//μè′yPLL1¤×÷
        RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK);//éè??PLL?a?μí3ê±?ó       
        while(RCC_GetSYSCLKSource()！=0x80);//?D??PLLê?·??a?μí3ê±?ó
/*******************************/
        RCC_HCLKConfig(RCC_SYSCLK_Div1);
        RCC_PCLK1Config(RCC_HCLK_Div2);
        RCC_PCLK2Config(RCC_HCLK_Div1);
}

应该是RCC的配置问题吧

串口的波特率和打印机要一致，否则会出错

时钟不要你专门配置，在启动文件中自动调用SystenInit这个函数来初始化时钟，修改这个函数来修改你要达到的时钟频率，在配置串口或GPIO只要打开他们的时钟就行了