Getting digital signal through serial port

I’m new in this group, I have some questions about the work with the serial port of the beagle board, right now i have just installed Angstrom, i am also running a micro controller for sending the serial signal. Now I would like to get the 8 bit signal. what kind of functions can i use?.

If anyone could show me a page where i could find information, i would apreciate it.

Bogota, Colombia