Patent ID: 6497370
Filing Date: 2002-12-24
Classification: G06K

Abstract:
An integrated circuit card comprising:a write accessible memory; and an input circuit receiving a first binary signal transmitted by direct contact between the card and a reader and producing a write control signal that is dependent on a first data element to control the memory, the input circuit comprising a first comparator that receives the first binary signal and produces the first data element representing a voltage level of the first binary signal with respect to a first reference voltage, a control circuit that receives the first binary signal and produces a validation signal that is inactive if the voltage level of the first binary signal is between the first reference voltage and a second reference voltage that is below the first reference voltage, the validation signal being active if the level of the first binary signal is higher than the first reference voltage or if it is lower than the second reference voltage, and an inhibition circuit to inhibit the write control signal when the validation signal is inactive.