Communication device, cable device, and display device

A communication device comprising:

• a controller configured to
• output a first read-out command including a first address that is an address for read-out to a signal line to which the controller a plurality of slave devices are connected,
• receive a response signal including information corresponding to the first read-out command from one of the slave devices, via the signal line, the slave devices having the first address
• change the address for read-out to a second address in a first scheme when the controller receives the response signal, the first scheme being identical to a scheme used by a slave device not transmitting the response signal out of the slave devices having the first address in order to change an address of the slave device from the first address to another address, and
• output a second read-out command including the second address to the signal line.

A cable device comprising:

• a voltage detector configured to detect a voltage from a power supply line to which the cable device and a host device are connected;
• and
• a controller configured to output, in case of detecting a read-out command from a data signal line to which the cable device and the host device are connected, a first signal with a time length corresponding to a value of the voltage to a clock signal line to which the cable device and the host device are connected, and
• output, in case that a first signal is not detected on the clock signal line from another slave device different from the host device after output of the first signal ends, a second signal including cable information to the data signal line.

A display device comprising:

• a voltage detector configured to detect a voltage from a power supply line to which the display device and a host device are connected;
• and
• a controller configured to output, in case of detecting a read-out command from a data signal line to which the display device and the host device are connected, a first signal with a time length corresponding to a value of the voltage to a clock signal line to which the display device and the host device are connected, and
• output, in case that a first signal is not detected on the clock signal line from another slave device different from the host device after output of the first signal ends, a second signal including display information to the data signal line.