A method and a circuit for checking data transferred between a circuit and a processing unit, in which: the data originating from the circuit transit through a first buffer element having a size which is a multiple of the size of data to be subsequently delivered over a bus of the processing unit; an address provided by the processing unit for the circuit is temporarily stored in a second element; and the content of the first element is compared with current data originating from the circuit, at least when they correspond to an address of data already present in this first element.