US Patent 9264021 Multi-bit flip-flop with enhanced fault detection

A processing system includes a processor core, a peripheral component, and a flip-flop unit in at least one of the processor core and the peripheral component. The flip-flop unit can include a master latch, and two slave latches coupled to an output of the master latch. The first slave latch is formed over a first doped well region of a semiconductor substrate. The second slave latch is formed over a second doped well region of the semiconductor substrate. A comparator is coupled to an output of the first slave latch and to an output of the second slave latch. An output of the comparator indicates whether a state stored in the first slave latch is the same as a state stored in the second slave latch.