Patent ID: 8559875

Claim:
A communication device for performing near field communication, comprising: a near field communication device having a near field communication section for performing near field communication in either one of communication modes, an active mode and a passive mode, the active mode being a communication mode for transmitting data by outputting an electromagnetic wave and modulating the electromagnetic wave in each of a plurality of devices for transmitting/receiving data, and the passive mode being a communication mode for transmitting data by outputting an electromagnetic wave and modulating the electromagnetic wave in one of the plurality of devices and for transmitting data in another of the plurality of devices by load-modulating the electromagnetic wave output by the one of the plurality of devices, and an interface section for supplying the near field communication section with data including identification information from a data processing device for processing data targeted by communication of the near field communication section, and supplying the data processing device with data from the near field communication section; and one or more of the data processing devices connected to the interface section by one output bus on which the data output by the interface section is transmitted, and one input bus on which the data input to the interface section is transmitted, wherein one of the one or more data processing devices includes bus right management means for judging whether or not a state, in which a voltage level of the input bus is an unused level representing that the input bus is not used, has continued for a predetermined time period determined using a random number, and for setting the voltage level of the input bus to an in-use level representing that the input bus is in use, thereby allowing the one of the one or more data processing devices to obtain a right of use of the input bus to transmit data and avoid transmission collision if it is judged that the state, in which the voltage level of the input bus is the unused level, has continued for the predetermined time period.