Acceleration of communication between I.C. card and data exchange equipment

摘要

The "I.C." card possesses electrical contacts for the voltage supply (VCC), a beat signal (CLK), a reference voltage/earth (GND), the data input/output (I/O) and the reset line (RST), all corresponding to contacts in the data exchange equipment. A rate for data transmission on the I/O line is derived from the clock frequency supplied by the data exchange equipment and a clock frequency division factor are stored in the card. There are at least two division factors possible depending on the information sent before the transmission of the "answer-to-reset" signal. After transmission there is a certain bit sequence, identifying the card type and the introduction to the communication, sent to the equipment.