US Patent 7309018 Semiconductor integrated circuit device and noncontact IC card

A semiconductor integrated circuit includes a demodulating circuit, a plurality of sampling circuits each capable of sampling output signals of the demodulating circuit, a plurality of detection circuits capable of detecting headers of output signals of the sampling circuits, a plurality of processing circuits capable of performing a predetermined data process based on the detection results of the detection circuits, and a circuit capable of determining a match to a preset communication method from results of the header detection by the detection circuits. By performing processes adapted to different communication methods in parallel, time required to establish a connection and enable information to be transmitted/received is reduced.