35.2.1.2 Transmitting Data

A transmission is initiated by writing a character to the UxTXB register. If this is the first character, or the previous character has been completely transmitted from the TSR, the data in the UxTXB is immediately transferred to the TSR register. If the TSR still contains all or part of a previous character, the new character data are held in the UxTXB until the previous character transmission is complete. The pending character in the UxTXB is then transferred to the TSR at the beginning of the previous character Stop bit transmission. The transmission of the Start bit, data bits and Stop bit sequence commences immediately following the completion of all of the previous character’s Stop bits.