632Chapter 15 Asynchronous Serial Interface C (UARTC)User’s Manual U16580EE3V1UD0015.5.5 UART transmit operationThe transmission enabled status is set by setting the UCnTXE bit of the UCnCTL0 register to 1, afterUCnPWR bit was set to 1, and transmission is started by writing transmit data to the UCnTX register.The start bit, parity bit, and stop bit are automatically added.The data in the UCnTX register is transferred to the UARTCn transmit shift register upon the start of thetransmit operation.A transmission enable interrupt (INTUCnT) is generated upon completion of transmission of the data ofthe UCnTX register to the UARTCn transmit shift register, and thereafter the contents of the UARTCntransmit shift register are output to the TXDCn pin LSB first.Write of the next transmit data to the UCnTX register is enabled by generating the INTUCnT signal.Continuous transmission is enabled by writing the data to be transmitted next to the UCnTX registerduring transfer.Figure 15-16: UART TransmissionRemark: If new data is written to the UCnTX register due to a transmission enable interrupt(INTUCnT) before the complete frame has been transferred, the next transmission enableinterrupt occurs at that time the stop bit begins.Startbit D0 D1 D2 D3 D4 D5 D6 D7 ParitybitStopbitINTUCnT
