A transceiver module is provided with a transceiver IC (PHY IC) having an XENPAK register group including an status register, and a DCU having an XENPAK register group which emulates the XENPAK register group. The PHY IC has an operation mode in which it does not reply to access to the XENPAK register group by a host while the DCU emulates the structure and function of the XENPAK register group.