US Patent 7620868 Method for detecting a malfunction in a state machine

A method for detecting a malfunction in a state machine is described. The state machine has an operation modeled by a set of states linked to each other by transitions, the state machine generating, upon each transition, output signals according to input signals comprising signals generated during a previous transition. During a transition, the method comprises steps of generating at least one control signal according to a control signal generated during a previous transition, determining an expected value of the control signal, and comparing the control signal with the expected value.