When an instruction decoder decodes an instruction code included in packet data, a copy flag and copy number information are provided to a self-synchronous transfer control circuit. In the self-synchronous transfer control circuit, when a data transfer enabling signal is applied from a C element in a subsequent stage, a node number manipulation circuit manipulates a node number to make copies such that packets can be distinguished from each other, and then data is transferred from a pipeline register to a pipeline register in a subsequent stage.