METHOD OF OPERATING SMART CARD AND METHOD OF OPERATING SMART CARD SYSTEM INCLUDING THE SAME

摘要

According to a method for operating a smart card of the present invention, during a first idle section, a power management unit deactivates a plurality of subunits based on a plurality of enable signals. During a clock stop section, a frequency detector and the power management unit detect an external clock signal and adjust a level of voltage provided to the subunits based on a control signal, generated by the frequency detector, and a plurality of level control signals generated by the power management unit according to the control signal. During a second idle section, the power management unit activates the subunits based on the enable signals. According to the method for operating a smart card of embodiments of the present invention, the frequency detector and the power management unit included in the smart card can reduce current by adjusting the level of voltage provided to the subunits based on the control signal and the level control signal during the clock stop section.