Chip card device with real time clock for e.g. credit card

摘要

In order to determine the time elapsing between two separate accesses to the data on the card, a real time clock (RTC) is provided so that this time can be determined internally by the card. With this method the time cannot be influenced from outside and also no external power is required in this time. The real time clock is equipped with an internal quartz timer for producing the beat and the clock has an internal energy buffer in the shape of a condenser or battery. The battery in this case is an extremely flat, lithium battery, formed in the body of the wafer.