In an error response circuit an analysis circuit unit analyzes a command transmitted from a first circuit section to a second circuit section, and detects a status of data transfer between the first circuit section and the second circuit section. A response circuit unit generates an error signal in accordance with the detected status of the data transfer in response to the second circuit section changing from a first power consumption state to a second power consumption state in which power consumption is lower than power consumption in the first power consumption state. A switching circuit unit transmits the error signal to the first circuit section in place of a response signal that is responsive to the command and transmitted from the second circuit section to the first circuit section.