IC CARD, IC CARD SYSTEM, AND DATA PROCESSOR

摘要

During communication in one direction by single end signal, a signal is fed to a receiver (6) from a transmitter (5) via damping resistors (R1//R2). During communication in the opposite direction, a signal is fed to a receiver (7) from a transmitter (8) via the damping resistors (R1//R2). Transmitters (9 and 12) for differential signal and receivers (10 and 11) for differential signal are kept disabled and in a high-impedance state with respect to a communication passage. During communication in the one direction of the differential signal, the signal is fed to the receiver (10) from the transmitter (9) via a terminating resistor (R1). During communication in the opposite direction, the signal is fed to the receiver (11) from the transmitter (12) via a terminating resistor (R2). In this communication, the transmitters (5 and 8) for single end signal and the receivers (6 and 7) for single-ended signal are kept disabled and in a high-impedance state with respect to the communication passage.