Strongly Fault Secure Logic Networks

Strongly fault secure logic networks are defined and are shown to include totally self-checking networks as a special case. Strongly fault secure networks provide the same protection against assumed faults as totally self-checking networks, and it is shown that when stuck-at faults are assumed a strongly fault secure network can be easily modified to form a totally self-checking network. A class of strongly fault secure networks is defined in terms of network structure. This structural definition of these "path fault secure" networks facilitates their design and implies other interesting properties. Finally, networks that are strongly fault secure with respect to single stuck-at faults are discussed. A large class of these networks is shown to be easily characterized, and network behavior under nonmodeled faults is considered.