Circuit arrangement having a chip card controller with connections which can be used to access the chip card controller in accordance with the ISO standard and which are connected or can be connected to an ISO interface. The connections include at least one first connection, which can be connected to the ISO interface via a switch device. In addition, the circuit arrangement includes a further controller with at least one controller connection which is coupled to the switch device such that the first connection of the chip card controller can be connected to the controller connection via the switch device. The switch device can be switched between a first and a second state, where in the first state the first connection of the chip card controller is decoupled from the controller connection and is connected to the ISO interface, and where in the second state the first connection of the chip card controller is decoupled from the ISO interface and is connected to the controller connection.