A semiconductor communication device includes a CRC calculation portion retrieving data pieces and CRC data piece as a retrieved data piece from a data signal, and performing a cyclic redundancy check calculation to obtain a CRC calculation value according to the retrieved data piece each time when the CRC calculation portion retrieves the retrieved data piece; a comparing portion generating an end detection signal indicating that the comparing portion detects a data end portion of the data signal when the CRC calculation value matches a value indicated with a subsequently retrieved data piece subsequently retrieved after the retrieved data piece is retrieved; and a communication responding portion determining whether the command is a non-corresponding command, and transmitting a command error signal when the communication responding portion determines that the command is the non-corresponding command.