Integrated-circuit card with a low power consumption mode

Claim 1

A semiconductor integrated-circuit card including a memory means, and a data processing means fabricated on a single semiconductor chip and communicable with said memory means and an external signal source, said data processing means having an interrupt signal port connected with said external signal source and a clock signal port connected with said external signal source (and) said data processing means selectively enterring into an active mode of operation capable of processing data and a low power consumption mode of operation disabled from processing said data, said data processing means being characterized by a) first mode shift means responsive to activation of said data processing means for estabilishing said low power consumption mode of operation in said integrated-circuit card when the data processing means is initially activated to start operation, said data processing means selectively disabling component units thereof in said low power consumption mode. said interrupt signal port remaining in enabled state in said low power consumption mode of operation, a clock signal being supplied from said external source to said clock signal port in said low power consumption mode of operation for allowing said data processing means to monitor said interrupt signal port to see whether or not an interrupt signal is supplied from said external signal source, b) second mode shift means responsive to (an) said interrupt signal from (an) said external signal source to said interrupt signal port for making a shift from said low power consumption mode of operation to said active mode of operation and enabling said data processing means to process said data with said clock signal, and c) third mode shift means for making a shift from said active mode of operation back to said low power consumption mode of operation upon termination of the data processing in said active mode of operation.