Data communication device

A data communication device comprising:

• a command interpretation device that is connected to a main device, and that:
• receives, from the main device, a main signal including a command signal, an address signal that designates an address of at least one register included in at least one sub-device, and a write data signal for storing in the register corresponding to the address, and
• interprets the command signal;
• and
• at least one sub-device connected to the command interpretation device via a first signal line through which a clock signal is transmitted, and via a second signal line through which a data signal is transmitted,
• wherein the command interpretation device is configured to:
• generate a write instruction signal when information based on the data signal is written to one of the at least one sub-device based on an interpretation result of the command signal,
• generate the data signal that is based on the address signal and the write data signal and that is supplied to each of the at least one sub-device based on the interpretation result of the command signal, and
• supply, to each of the at least one sub-device, the write instruction signal via the first signal line or via the second signal line, and supply the data signal via the second signal line, and
• wherein each of the at least one sub-device is configured to:
• determine whether the register corresponding to the address specified by the address signal is included in the at least one sub-device or not, and
• write the write data signal to the register when the register is included in the at least one sub-device and the write instruction signal is supplied from the command interpretation device.