10.4.12 Dual Core Lockstep

The lockstep system executes the same program flow on two identical CPUs operating in lockstep, and a comparator compares the state of the two CPUs. A detected mismatch in their state will trigger a Machine Check Reset directly, without handling by the Error Controller.

The lockstep comparator is located outside the main CPU.

To inject a comparator error, use the Inject Comparator Error (INJCOMP) bit in the Control A (CTRLA) register. Writing this bit will instruct the comparator to inject an error and trigger a Machine Check Reset.

See the Functional Safety Concept section for more information about the functional safety mechanisms included in this device family.