A method for the secured storing of a data element in an external memory, which is connected to a microcontroller via an interface module, which is configured to calculate memory addresses for data to be stored and for error correction values. The method includes receiving the data element to be stored by the interface module, a calculation by the interface module of a memory address in the external memory for the data element to be stored, and a writing, starting at the memory address, of the data element and of the error correction value via the interface module into the external memory, the error correction value immediately following the data element being written and the writing taking place within one addressing phase. A corresponding interface module, a corresponding microcontroller, and a corresponding control unit are also described.