Abstract:
A semiconductor device which stores data, and in which refresh operation is not needed, is described. The semiconductor device comprises at least a transistor and a capacitor. A first electrode of the capacitor is connected to a reference voltage terminal and a second electrode of the capacitor is connected to one of a source and a drain of the transistor. The semiconductor device is configured to put, when necessary, the other of the source and the drain of the transistor to the same potential as the one of the source and the drain, so that charge accumulated in the capacitor, which is connected to the one of the source and the drain of the transistor, does not leak through the transistor.
Abstract:
PROBLEM TO BE SOLVED: To provide an IC card having higher convenience, a portable electronic device, and a reader writer for the IC card.SOLUTION: An IC card according to one embodiment is an IC card for performing non-contact communication with an external apparatus which includes a first battery for storing electric power and a first carrier wave output unit for outputting a carrier wave by using electric power of the first battery. The IC card comprises: a second battery for storing electric power; a second carrier wave output unit for outputting the carrier wave by using electric power of the second battery and supplying electric power to the external apparatus; a battery residual amount reading unit for acquiring information which shows residual amount of the first battery; and a comparison unit for comparing residual amount of the first battery with residual amount of the second battery.
Abstract:
PROBLEM TO BE SOLVED: To provide an IC card, a portable electronic device, and an IC card reader/writer which allow faster non-contact communication.SOLUTION: An IC card according to one embodiment, which performs non-contact communication with an external apparatus, includes: a receiving unit that receives a command transmitted from the external apparatus; a command processing unit that, when the command is received by the receiving unit, executes command processing based on the command and generates a response; and a transmission unit that transmits the response to the external apparatus in one of a plurality of time frames in which the data can be transmitted to the external apparatus.