Hi can you give me some basic information about subsystem for sequential asynchronous data exchange of the MSP430F663X?

 

Asynchronous data exchange is done one character at a time. Each character is typically 8 bits long and each bit takes the same amount of time. To these data bits are added a START bit at the beginning of the character and a STOP bit at the end of the character. After the START bit, the least significant bit of the character goes next. After all 8 bits have been sent the STOP bit goes last.

Characters can be sent one after the other with an arbitrary delay between the characters. The total time it takes to send a character allows for some differences in the bitrate clocks in the transmitter and the receiver. That is they do not have to run at the same frequency or be synchronized. They do have to be close in frequency and they resynchronize themselves at the beginning of each character when the receiver recognizes the START bit.

What more do you want to know?