| Testgen (Faultlist) |
| begin |
| Set primary objectives ( );/*find all the primary |
| objectives to be justified*/ |
| Set all other lines to X |
| if (there is conflict between two or more objectives on the fan-out branches of |
| the same stem) then |
| begin |
| Drop the aggressor objectives; |
| If (all aggressors objectives dropped) |
| begin |
| then test not possible; |
| Exit |
| End |
| end |
| Imply ( ) /*with respect to the victim and remaining aggressors and other inputs*/ |
| Propagate ( ) /*Propagate the victim along the chosen target path*/ |
| if (there is conflict between the objectives) then |
| begin |
| Drop the aggressor objectives; |
| If (all aggressor objectives dropped) then |
| begin |
| test not possible |
| Exit( ) |
| end |
| end |
| Multiple back trace ( ) |
| Unassigned primary inputs are assigned |
| Imply ()/*with respect to primary inputs*/ |
| Propagate ( );/*Propagate the delay in the victim along the target path*/ |
| if (delay effect at PO) |
| test is found; |
| else |
| begin |
| no test possible |
| Exit( ) |
| end |
| end |
| Multiple back trace ( ) |
| begin |
| repeat |
| begin |
| remove one entry from the current objective; |
| if (objective follows a fan-out point) then |
| begin |
| if (there is a contradiction with a previously assigned value) |
| begin |
| move the objective to a secondary stack |
| else |
| move the objective to a primary stack |
| end |
| else |
| begin |
| Continue tracing |
| Select an input of gate with value x |
| add to the current objective |
| return multiple backtrace |
| end |
| end |
| end |
| until current objectives ≠ null |
| if (primary stack objective ≠ null) then |
| begin |
| remove the highest level objective |
| assign most requested value; |
| add to the current objective |
| return multiple back trace ( ) |
| end |
| if (secondary stack objective ≠ null) |
| begin |
| remove the highest level objective |
| repeat |
| begin |
| assign value to the fan-out point |
| Imply ( ) |
| if (success) |
| begin |
| add to the current objective |
| return multiple back trace ( ) |
| end |
| else |
| assign next value |
| end |
| until all values assigned |
| if (assignment not possible) |
| begin |
| Drop the aggressor objectives; |
| If (all aggressor objectives dropped) then |
| begin |
| test not possible |
| Exit( ) |
| end |
| end |
| end |
| end |
