Reducing the area overhead of TMR-systems by protecting specific signals

This paper presents a new method of fault-tolerant design for combinational circuits. For an arbitrary chosen subset X₁ of inputs the designed system is fault-tolerant, but not necessarily for the other inputs. For all the inputs from X₁ the same level of fault tolerance as for Triple Modular Redundancy (TMR) is achieved. Compared to TMR the necessary area can be significantly reduced. Since the subset X₁ of inputs, for which the system is fault-tolerant, can be chosen by the designer, the proposed fault-tolerant design method is optimally adapted to the real requirements of fault tolerance.