Scan chains are added to make the design testable..! If there is a fault ( like STUCK at 0 or STUCK at 1) in the circuit, it can be detected if it is OBSERVABLE at primary output by CONTROLLING the primary inputs of circuit. Fault is propagated to primary output using scan chains.!
Scan chains are added to make the design testable..! If there is a fault ( like STUCK at 0 or STUCK at 1) in the circuit, it can be detected if it is OBSERVABLE at primary output by CONTROLLING the primary inputs of circuit. Fault is propagated to primary output using scan chains.!