Abstract: A reader/writer includes two antennas that perform reading/writing of information from/to wireless tags that are moving. The antennas are positioned in such a manner that their communication ranges have an overlap along a route in which the wireless tag moves.

Abstract: A non-contact IC recording medium that operates in response to a radio instruction from a reader/writer includes a write-protect area setting unit that sets a write-protect area where a writing of data is prohibited; an area determining unit that determines, when data for the writing is received, whether an area where the data is to be written is the write-protect area; and a write processing unit that writes, when the area determining unit determines that the area is not the write-protect area, writes the data in the area, and changes the area into the write-protect area.

Abstract: A proximity IC card (PICC) which relates to and provides a carrier synchronization type demodulator, which is able to stably receive a PSK signal from a PICC and is enhanced in noise immunity, and which is realized at a low cost and in such a way as to have a small size. The carrier synchronization type demodulator is adapted to receive and demodulate PSK-modulated subcarrier signals to be synchronized with and superposed onto a sent carrier signal.

Abstract: The present invention relates to a proximity IC card (PICC). More particularly, the present invention relates to and provides a detection circuit of a simple structure, which is easy to set up in a PICC and a proximity coupling device (PCD) for transmitting data to and receiving data from the PICC. This detection circuit is operative to detect a subcarrier signal sent from a PICC and superposed onto a carrier signal received through an antenna. Further, this detection circuit comprises a bias circuit for applying predetermined DC potential to a signal received from the antenna, a rectifier circuit for extracting a subcarrier signal superposed onto the carrier signal by rectifying a signal received from the antenna at a bias point, and an amplifier circuit for amplifying the subcarrier signal extracted at the bias point.

Abstract: A circuit, of a simple structure, for detecting the presence or absence of a proximity IC card (PICC) in a proximity coupling device (PCD) which transmits data to and receives data from the PICC. This circuit includes an antenna for receiving a carrier signal outputted to a proximity IC card, a D.C. detecting device for rectifying a carrier signal received from the antenna and for detecting a D.C. component of the received carrier signal, and a level judgment device for determining the level of the D.C. component detected by the D.C. detecting device and for judging, when the level of the direct component is within a predetermined range that a proximity IC card is present in an RF field.

Abstract: An electronic apparatus is provided that can prevent wrongful reverse analysis by a third party. Authorization functions are provided in the electronic apparatus for judging whether or not to enable utilization of debugging functions. The authorization functions send command data to an external device connected to the electronic apparatus, based on a debug request containing the designation of a prescribed address range in the internal circuitry of the electronic apparatus, a first authorization is performed, based on the command data and on reply data to the command data received from the external device, a second authorization is performed, based on a user code received from the external device following the reply data, and use of the debugging functions is enabled, based on the first authorization and the second authorization.

Abstract: An interrupt control system in which a main process device executes an interrupt process, having a high process priority. The process priority is registered in a table, corresponding to each interrupt generating source, and an intermediate process device receives an interrupt signal from each interrupt generating source, obtains the corresponding process priority from the table and informs the main process device of the interruption. Accordingly, the process priority can be easily changed, and the system has a small size because the interrupt circuit for the main process device is centralized.