The LTC1543 is a 3-driver/3-receiver multiprotocol transceiver that operates from a single 5V supply. The LTC1543 and LTC1544 form the core of a complete software-selectable DTE or DCE interface port that supports the RS232, RS449, EIA530, EIA530-A, V.35, V.36 or X.21 protocols. Cable termination may be implemented using the LTC1344A software-selectable cable termination chip or by using existing discrete designs.