Communication circuit and method

Disclosed is a communication circuit, for monitoring and maintaining an interface transmission path, which is connected to an opposite communication circuit via a plurality of serial data transmission paths and includes a link establishment detector, an idle generator and a link monitoring unit. The link establishment detector detects link status, which indicates whether reception is possible from receive data that enters from the plurality of serial data transmission paths, and outputs link establishment information. The idle generator generates transmit data, which indicates the link status, based upon the link establishment information and transmits the transmit data to the plurality of serial data transmission paths. The link monitoring unit extracts the link establishment information, which is sent by the opposite communication circuit, from the receive data that enters from the plurality of serial data transmission paths. The communication circuit sends and receives the link establishment information to and from the opposite communication circuit, whereby the communication circuits monitor each other's link status.