Texas Instruments MSP430x4xx - Manual (Page 283)

USART Registers: UART Mode
14-26 USART Peripheral Interface, UART Mode
UxRXBUF, USART Receive Buffer Register
7 6 5 4 3 2 1 0
2 7 2 6 2 5 2 4 2 3 2 2 2 1 2 0
r r r r r r r r
UxRXBUFx Bits
7−0 The receive-data buffer is user accessible and contains the last received
character from the receive shift register. Reading UxRXBUF resets the
receive-error bits, the RXWAKE bit, and URXIFGx. In 7-bit data mode,
UxRXBUF is LSB justified and the MSB is always reset.
UxTXBUF, USART Transmit Buffer Register
7 6 5 4 3 2 1 0
2 7 2 6 2 5 2 4 2 3 2 2 2 1 2 0
rw rw rw rw rw rw rw rw
UxTXBUFx Bits
7−0 The transmit data buffer is user accessible and holds the data waiting to be
moved into the transmit shift register and transmitted on UTXDx. Writing to
the transmit data buffer clears UTXIFGx. The MSB of UxTXBUF is not
used for 7-bit data and is reset.