SAFE COUNTING METHOD FOR BINARY ELECTRONIC COUNTER

摘要

PURPOSE: To install a counter by which count is required to be performed under high safety. CONSTITUTION: In the counter to start counting from a number indicated by plural bits, a stage of the counter is set to consecutively display the last numbers one by one in order that no number less than the initial number is indicated by contents of the counter. Registers 301, 311, 302, 303 are capable of counting extremely large numbers through they are EEPROM type technology. Consequently, the counter is prevented from being affected by a motion with frequency more than the frequency physically allowed by technology used by the stage to change state of the registers. Therefore, e.g. a stored value to indicate a substantial value as the value of an amount is prevented from being reduced in a chip card by a disclosed method.