A logic circuit comprises a logic module comprising a functional synchronous flip-flop receiving a functional result comprising several bits in parallel, and supplying a synchronous result. A module for checking the integrity of the functional flip-flop comprises a first coding block receiving the functional result and supplying a first code, a second coding block receiving the synchronous result and supplying a second code, a checking synchronous flip-flop receiving the first code and supplying a third code, and a comparator for comparing the second code with the third code and for supplying a first error signal.