This reference design for an RF modem demonstrates both low-level and protocollevel design using the CC1020 RF transceiver. Software is described in detail, while hardware is based on CC1000 RF Modem and described in AN015.

A pair of RF modems function as a wireless replacement of an ordinary RS-232 serial cable. The modem will function with equipment and software supporting hardware handshaking and half-duplex communication. The function of the modem is completely transparent, but RF frequency, output power and other parameters are  user-definable.
The hardware is designed as a motherboard in which a CC1020EMX module can be inserted via a simple redirection-adapter. The use of modules allows the basic RF modem design to be used with different RF modules.
The software handles transceiver configuration and data flow.

http://www.ti.com/litv/pdf/swra067
Download associated code files