Patent ID: RE45205

Claim:
An IC chip configured for incorporation into a portable communication terminal apparatus, the IC chip comprising: a memory for storing information; a wireless communication unit for receiving an electromagnetic wave from an external reader/writer; an analog signal processing unit for processing the received electromagnetic wave, said analog signal processing unit including a carrier wave detection unit for detecting a carrier wave from the electromagnetic wave received by the wireless communication unit to output a carrier wave detection signal; an interface unit configured for connection to a program control unit residing outside the IC chip but within the portable communication terminal apparatus, the connection to the program control unit being through a wired interface when the IC chip is incorporated into the portable communication terminal apparatus; and a digital control unit for processing a signal outputted from the analog signal processing unit and controlling access to the memory according to an access request from the external reader/writer or an access request from the program control unit through the interface unit, wherein said digital control unit notifies said program control unit of the portable communication terminal apparatus of an internal state of the IC chip, which said internal state changes according to the wireless communication with the external reader/writer, by the carrier wave detection signal detected.