A method of controlling a transceiver module which includes a physical-layer integrated circuit having a physical-layer register unit, and a control integrated circuit having a control-side register unit. In the method, the physical-layer register unit is emulated by the control-side register unit and the physical-layer integrated circuit is prohibited from generating a first error signal giving notice of detection of a specific error directly to a higher-layer device. A second error signal is output from the physical-layer integrated circuit to the control integrated circuit, giving notice of a high-speed error associated with communication processing and that is detected by the physical-layer integrated circuit. The high-speed error is specified in response to the outputting of the second error signal. A bit is set in the control-side register unit in response to the specifying of a high speed error and the control integrated circuit delivers to the higher-layer device the second error signal.