PURPOSE: To optimize the state allocation, and also, to facilitate the configuration of a control circuit by changing a finite state machine so that plural terms become simultaneously an operating state and plural fundamental states become simultaneously an operating state.

CONSTITUTION: In a source block 13, a parallel state is discriminated, it is allocated to each different position of a code word of a state structure, and in a target block 15, as well, the same allocation is executed, and also, parallel terms 14 discriminate in parallel the corresponding source, operate in parallel, and generate in parallel the corresponding target code. In such a way, a finite state machine(FSM) model is changed so that two or more terms 14 become simultaneously an operating state, and two or more fundamental states become simultaneously an operating state, and by executing optimumly and easily the state allocation, based on one FSM, the control circuit can be constituted.