A semiconductor device that can perform high speed data communication is provided.The semiconductor device includes a communication chip that performs authentication processing that determines whether or not data communication can be performed with an external device and performs the data communication with the external device when the authentication processing is successfully performed and a control chip that performs data processing of transmission/reception of the data communication through the communication chip. The communication chip includes a first memory that stores authentication data for the authentication processing. The control chip includes a second memory for the data processing.