A memory circuit comprising a memory area for storing data, a non-volatile memory area for storing at least one identification code, and a pin for storing the identification code in the non-volatile memory area. The memory circuit further comprising a programmable register in which a programmable state is fixed, wherein the programmable state indicates if the identification code has been stored in the non-volatile memory area, and a logic module which blocks any subsequent changes to the identification code fixed in the non-volatile memory area in response to the programmable state in the programmable register indicating that the identification code has been stored in the non-volatile area. The invention also relates to an associated method. The invention is useful particularly to avoid fraudulent reprogramming of the area containing the identification code. The invention also relates to an associated method.