uart全功能实现.实现如下函数:

U_Open,

U_Close,

U_GetBytes,

U_PutBytes,

U_GetBytesAvail,

U_GetTxRoomLeft,

U_PutISRBytes,

U_GetTxISRRoomLeft,

U_Purge,

U_SetOwner,

U_SetFlowCtrl,

U_ConfigEscape,

U_SetDCBConfig,

U_CtrlDCD,

U_CtrlBreak,

U_ClrRxBuffer,

U_ClrTxBuffer,

U_SetBaudRate,

U_SendISRData,

U_SendData,

U_GetOwnerID,

U_SetAutoBaud_Div,

/*TY adds these to expand flexibility 2004/10/15*/

U_Register_TX_cb,

U_Register_RX_cb,

/*TY adds these to let virtual COM port can retrive exception log 2005/3/8*/

U_GetUARTByte,

U_PutUARTByte,

U_PutUARTBytes,

/*for virtual com port to return DCB configuration*/

U_ReadDCBConfig,

U_CtrlRI,

U_CtrlDTR,

U_ReadHWStatus