A control and communication unit is provided between a terminal and at least one microcircuit card. The unit includes a control module for a number of input signals to the card; a module for generation of a number of time diagrams for the card communication protocols; a request generation module for transmission and reception of characters based on information received from the control module, the requests being transmitted to an external module; and an interruption generation module for creating an interruption in the case of an error in a time diagram or a character received or transmitted, based on information received from the control module and for processing the interruption without a loss of characters. The generation of an interruption does not cause an interruption in the process of request generation.