In this example we are going to configure the MSP430 UART to transmit and receive at 9600bps with 8 databits,no Parity and 1 Stop bit. You can see the (very) simplified block diagram of USCI_A0 in UART mode below. Asynchronous serial communication is widely used for communicating with external devices like PC/Laptops,GSM modems,GPS modules etc.It also forms the basis for many standard protocols like RS232, RS422, RS485 etc. In this article we we will configure USCI_A0 in MSP430G2553 to handle asynchronous serial communication or commonly known as UART mode.The UART mode uses two pins to transmit ( UCA0TXD ) and receive data( UCA0RXD). USCI_A0 can be configured to handle LIN,IrDA,SPI and asynchronous serial communication (UART) while USCI_B0 can handle SPI and I2C.

MSP430G2553 has two USCI modules names as USCI_A0 and USCI_B0 for handling multiple communication formats. The peripheral is designed in such a way that it can handle multiple serial communication formats ,synchronous as well as asynchronous like SPI, I2C,IrDA, UART etc.

In MSP430, serial communication is handled by an on chip peripheral called USCI ( Universal Serial Communications Interface).

Uart serial communication pdf