176 VLSI Test Principles and Architectures Algorithm 4 PropagateFanoutFree( C , g ) 1: if g has exactly one fanout then 2: h = fanout gate of g ; 3: if none of the inputs of h has the value of X then 4: backtrack; 5: end if 6: else ±g has more than one fanout ² 7: h = pick one fanout gate of g that is unjusti±ed; 8: end if 9: if gate type of h == AND gate then 10: for all inputs, j ,of h , such that j ±= g do 11: if the value on j == X then 12: JustifyFanoutFree( C , j , 1); 13: end if 14: end for 15: else if gate type of h == OR gate then 16: for all inputs, j ,of h , such that j ±= g do 17: if the value on j == X then 18: JustifyFanoutFree( C , j , 0); 19: end if 20: end for 21: else if gate type of h == ³³³ gate then 22: ³³³ 23: end if 24: PropagateFanoutFree( C , h ); Because the fault-effect has successfully propagated to the primary output z , the fault g/ 0 is detected, with the vector abc = 100. The reader may notice that once
This is the end of the preview. Sign up
access the rest of the document.