A semiconductor device includes three integrated circuits. One of the integrated circuits includes: a first connector configured to connect to a device; and a transmitter. The transmitter is configured to transmit to another integrated circuit, first data on each of a plurality of pieces of packet data. The transmitter is also configured to, when the first connector is connected to the device, while a second controller is performing a second process, transmit, to a first controller, a request to process data transmitted from the device.