A novel methodology for designing TSC networks based on the parity bit code

Combinational circuits encoded with the parity bit code can be defined TSC if and only if the number of the observed outputs modified by any admissible fault (fault observability) is odd. The methodology presented in this paper allows the use of the parity bit code by synthesizing an encoded network and then modifying the observability of each fault f∈F by introducing an auxiliary output, if necessary. In particular, the function implementing the auxiliary output allows an odd observability every time the observability of an internal node in the initial realization is even.