a reception circuit configured to receive a first frame from an external device;

a transmission circuit configured to transmit a second frame to the external device; and

a controller configured to execute a function of a data link layer among a plurality of communication layers of Unified protocol (UniPro),

wherein the controller is configured to obtain a frame sequence number indicating a sequence of the first frame from the first frame before storing the first frame in a reception buffer, and

wherein the controller is configured to execute a cyclic redundancy check (CRC) on the first frame before storing the first frame in the reception buffer, and add the frame sequence number to the second frame when the CRC succeeds.