IC card compatible with different supply voltages, IC card system comprising the same, and IC for the IC card
June 3, 2017. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent ReferencesIC card reader/writer Phase control loop with interrupted control Voltage transient protection circuit Clock signal switching device of an IC Card IC card reader/writer having a short-circuit detection capability IC card with dual level power supply interface and method for operating the IC card Portable electronic device having an external I/O unit and power source integral therewith IC card connector apparatus Internal state determining apparatus Hot plug protection system InventorApplicationNo. 868154 filed on 06/03/1997US Classes:710/301, Card insertion713/100, RECONFIGURATION (E.G., CHANGING SYSTEM SETTING)713/322By clock speed control (e.g., clock on/off)ExaminersPrimary: Myers, Paul R.Attorney, Agent or FirmForeign Patent References
International ClassG06F 013/00Foreign Application Priority Data1996-06-07 JPAbstractAn IC card has a peripheral circuit and a CPU. The peripheral circuit has a memory for storing data. The CPU controls various operations including an access operation of the memory. The IC card receives a supply voltage and a clock signal from an external unit. The IC card has a detector for detecting the supply voltage, a tester for testing the detected supply voltage, and an adjuster for adjusting the peripheral circuit according to a result of the voltage test. With these arrangements, the IC card stably operates on a wide range of supply voltages and is capable of coping with a fluctuation in the supply voltage. The tester may be incorporated in the CPU as one of functions thereof or may be realized by hardware that is arranged outside the CPU. The IC card and external unit constitute an IC card system. | |
