模拟USART输出有问题，请大家帮忙看看

int main(void)
{
        unsigned char i,data;
        USART_InitTypeDef USART_InitStructure;
        RCC_Configuration();
        GPIO_Configuration();
        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);
        data = 'A';
        for(i=0; i<10; i++)
        {
               
                USART_SendData(USART1,data);
                data++;
                while(USART_GetFlagStatus(USART1,USART_FLAG_TC)==RESET);               
        }
}
我明明循环了10次，却只打印出了9个数据，原本想输出“ABCDEFGHIJ”，但是实际输出出来的是“ACDEFGHIJ”