Mobile telephone device for carrying out an aging operation without interference with a mobile telephone system

A mobile telephone device comprising a serial interface and subjectable to an aging operation with an aging device connected to said serial interface, said aging device being for generating particular data, said mobile telephone device comprising:

• clock delivering means connected to said serial interface for delivering a clock signal to said aging device through said serial interface, said clock delivering means thereby triggering said aging device to make said aging device supply particular data to said serial interface;
• data receiving means connected to said serial interface and to said clock delivering means for receiving serial data as received data in synchronism with said clock signal, said serial data being supplied to said serial interface both during progress of said aging operation and while said mobile telephone device is not subjected to said aging operation;
• judging means connected to said data receiving means for judging whether or not said received data coincides with said particular data;
• and
• aging means connected to said judging means for carrying out said aging operation when said received data coincides with said particular data.