Video display device, method of displaying connectors, transmission-line state detection device, transmission line-state detection method and semiconductor integrated circuit

A method of displaying connectors in a video display device including connectors to which cables transmitting video signals are connected and a display panel displaying video by the video signal inputted to the connector from an external device through the cable, the method comprising the steps of:

• displaying connector indications indicating the connectors on the display panel;
• outputting a step waveform signal having a rising time of approximately 2 nanoseconds to the connector and detecting connection/disconnection of the cable to the connector based on a reflected signal of the step waveform signal;
• and
• changing the appearance of connector indications displayed on the display panel according to the detection result of the step of detecting the cable,
• the step waveform signal being coupled to a multiple of waveform shaping circuits, at least one of the waveform shaping circuits comprising a dummy output resistance and a reference load, the values of the dummy output resistance and the reference load being selected to set a maximum margin for cable detection.

A transmission-line state detection method comprising the steps of:

• outputting a step waveform signal having a rising time of approximately 2 nanoseconds to a connection portion of a transmission line for performing reception or transmission of a signal;
• and
• detecting a state of the transmission line based on a reflected signal of the step waveform signal,
• the step waveform signal being coupled to a multiple of waveform shaping circuits, at least one of the waveform shaping circuits comprising a dummy output resistance and a reference load, the values of the dummy output resistance and the reference load being selected to set a maximum margin for transmission line status detection.

A semiconductor integrated circuit comprising:

• a connection portion of a transmission line for performing reception or transmission of a signal;
• and
• a transmission-line state detection unit outputting a step waveform signal having a rising time of approximately 2 nanoseconds to the connection portion and detecting a state of the transmission line based on a reflected signal of the step waveform signal,
• the step waveform signal being coupled to a multiple of waveform shaping circuits, at least one of the waveform shaping circuits comprising a dummy output resistance and a reference load, the values of the dummy output resistance and the reference load being selected to set a maximum margin for transmission line status detection.