Transmitting device, transmitting method, and communication system

A transmitting device comprising:

• a driver unit that transmits a data signal with use of a predetermined number of voltage states which are three or more voltage states, and is allowed to set a voltage in each of the voltage states;
• a controller that sets an emphasis voltage in accordance with a transition between the predetermined number of voltage states, thereby causing the driver unit to perform emphasis;
• and
• a voltage generator, wherein
• the driver unit includes a first switch provided on a path from a first power source to an output terminal, a second switch provided on a path from a second power source to the output terminal, and a third switch provided on a path from the voltage generator to the output terminal.

A communication system provided with a transmitting device and a receiving device, the transmitting device comprising:

• a voltage generator that generates a predetermined voltage;
• a first driver including a first sub-driver and a second sub-driver, the first dub-driver that includes a first switch provided on a path from a first power source to a first output terminal, a second switch provided on a path from a second power source to the first output terminal, and a third switch provided on a path from the voltage generator to the first output terminal, and is allowed to set a voltage state of the first output terminal to any of a predetermined number of voltage states which are three or more voltage states, and the second sub-driver that is allowed to adjust a voltage in each of the voltage states of the first output terminal;
• and
• a controller that controls an operation of the first driver to perform emphasis.