Abstract: The present invention provides a transmission/reception apparatus capable of achieving both a high processing speed and good extensibility in performing communication protocol processes. Used for transmitting data in accordance with a predetermined communication protocol and receiving data transmitted in accordance with the predetermined communication protocol, the transmission/reception apparatus has a configuration capable of executing communication protocol processes by using hardware (in first and second communication-protocol-processing units) and software (in first and second control units). The hardware or the software can be selected properly in accordance with the type of data. For example, a communication protocol process for data regarded as a heavy processing load can be carried out by using the hardware at the high processing speed whereas a communication protocol process for data regarded as a light processing load can be carried out by using the software, which offers the good extensibility.