华大mcu用串口发数据，串口调试助手接收数据异常

`Uart_SendData(UARTCH0, 'd');
函数原型：en_result_t Uart_SendData(uint8_t u8Idx, uint8_t u8Data){
    stc_uart_instance_data_t *pstcData = NULL;
    ASSERT(IS_VALID_CH(u8Idx));
    pstcData = UartGetinternDataPtr(u8Idx);
    if (NULL == pstcData)
    {
        return ErrorInvalidParameter;
    }
    Uart_ClrStatus(u8Idx,UartTC);
    pstcData->pstcInstance->SBUF_f.DATA = u8Data;
    while(FALSE == Uart_GetStatus(u8Idx,UartTC))
    {}
    Uart_ClrStatus(u8Idx,UartTC);      
    return Ok;
}<
/font>
但是发送后串口调试助手却收到如图数据
按道理发送d,应该就显示d(十六进制为64)，这是怎么回事，求大神指教
`