A circuit generally including a control function and a checksum function is disclosed. The control function may be configured to assert (i) a start signal in response to a signal having a predetermined sequence of values matching an entry value and (ii) a stop signal in response to the signal matching an exit value. The checksum function may be configured to (i) generate a checksum value for the signal between assertions of the start signal and the stop signal and (ii) generate a result signal in response to comparing the checksum value with an expected value.
A method for monitoring the execution of a sequence of instruction codes in an integrated circuit comprising a central processing unit provided for executing such instruction codes. In one embodiment, the method comprises producing current cumulative signatures during the execution of a sequence, until a final cumulative signature is obtained, producing an error signal having a value active by default while the current cumulative signature is different to an expected signature, measuring a predetermined time interval that is substantially longer than the presumed duration of execution of the sequence, masking the error signal during the measurement of the time interval, and lifting the masking of the error signal when the time interval expires.
