The first store unit (R1) for receiving and storing the first input (AI), the second store unit (R2) for receiving and storing the second input (BI), a selection unit (SEL) for selecting one of outputs from the first inverter (IV1) and the second inverter (IV2) in the second store unit (R2) in response to an output of the first store unit (R1) are provided in an operation circuit. This constitution, which has a function of storing the first input (AI) and the second input (BI) and a function of performing an exclusive-OR operation between the first input (AI) and the second input (BI), allows reduction in circuit scale.