Card reader for second generation synchronous microprocessor chip prepayment cards, using cabled logic fixed frequency pulse train generator

摘要

The reader has a microprocessor (1) to manage the data exchange between the reader and card (2) introduced into an electric coupler (4). The microprocessor delivers at least a control signal (A/RST) and receive an input/output signal (I/O) on a bit. The reader has a cabled logic pulse train programmable generator.(32) designed to deliver a fixed frequency pulse signal to the electric coupler so as to increment a counter on the card. The pulse generator has an output terminal for a priority interruption signal (NM) sent to the microprocessor. The number of pulse generated is programmed by the microprocessor (1). On a transmission a clock signal is sent to the card. A selector (31) selects the clock signal between the microprocessor output and the output of the pulse generator. The output of the pulse generator is selected for each card counter increment cycle.