Device for determining the mask version utilized for each metal layer of an integrated circuit

A device for determining a version of metal mask utilized for producing a given metal layer in an integrated circuit comprising a plurality of metal layers, wherein any modification made to the given metal layer requires generation of a new version of a corresponding metal mask, the device comprising:

• a cell integrated into a metal layer comprising:
• at least a first voltage source for supplying a first voltage level,
• at least a second voltage source for supplying a second voltage level, and
• an output bus comprising at least one conductor wire connected selectively to one of the first and second voltage sources as a function of a version of metal mask used to produce the metal layer, so as to generate a binary output signal representative of the version of metal mask utilized, wherein said binary output signal being independent from a binary output signal of, and representative of the version of metal mask utilized by, any other metal layer of the plurality of metal layers.