The fault simulation for existing test vectors can be performed either using the dedicated analyze tool or directly from the vecmanager. The analyze tool gives the following information (take a look at this log and at the comments given in between of two * (stars):
 
 

prompt> analyze c17	*give the name of the design to the fault simulator*
Fault Simulator for Combinational Circuits  Reading SSBDD-model file c17.agm... OK  Reading test patterns file c17.tst... OK  Simulating... OK  Time, used by process: 0.000000
Covered 20 of 22 faults	*the information here tells that 20 faults of *
Fault coverage: 90.909091	*22 possible faults are detectable by these*
4 vectors simulated	*4 patterns what gives 90.91 % cover*
Writing test patterns file c17.tst... OK	*saves here the fault table, the coverage,*
	*and other simulation information*

The fault simulation information can be obtained later either from this file (c17.tst) or in a more convenient way using the report tool. In the following, we give some examples of usage of the tool.

prompt> report -coverage c17	*use it to check out the fault coverage*
Generating Report  Reading SSBDD-model file c17.agm... OK  Reading test patterns file c17.tst... OK  Fault coverage: 90.909091 % (20/22)

 
 

prompt> report -patterns c17	*this option shows the number of test vectors*
Generating Report  Reading SSBDD-model file c17.agm... OK  Reading test patterns file c17.tst... OK  Number of patterns: 4

 
 

prompt> report -tested c17	*in this way we can look up which faults are testable*
Generating Report  Reading SSBDD-model file c17.agm... OK  Reading test patterns file c17.tst... OK  Tested faults:
Node 0 (x3): sa-0 Node 0 (x3): sa-1 Node 1 (x4): sa-0 Node 1 (x4): sa-1 Node 2 (g2>inp2): sa-0 Node 2 (g2>inp2): sa-1 Node 3 (g3>inp1): sa-0 Node 3 (g3>inp1): sa-1 Node 4 (x2): sa-0 Node 4 (x2): sa-1 Node 5 (x5): sa-0 Node 5 (x5): sa-1 Node 6 (g4>inp2): sa-0 Node 6 (g4>inp2): sa-1 Node 7 (g3>inp2): sa-0 Node 7 (g3>inp2): sa-1 Node 8 (g5>inp1): sa-0 Node 8 (g5>inp1): sa-1 Node 9 (g1>inp1): sa-0 Node 10 (x1): sa-0  ------------------------  Total of 20 nodes tested	*stuck-at 0 is tested at Node 0 (at the input x3)* *stuck-at 1 is tested at Node 0 as well* *stuck-at 0 is tested at Node 1 (at the input x4)* *stuck-at 0 is tested at the second input of g2* *and so on*

 
 

prompt> report -not_tested c17	*shows the faults that remained untested*
Generating Report  Reading SSBDD-model file c17.agm... OK  Reading test patterns file c17.tst... OK  Not tested faults:  Node 9 (g1>inp1): sa-1  Node 10 (x1): sa-1  ------------------------  Total of 2 nodes not tested

 
 

prompt> report -untestable c17	*shows the faults for which it is proven* *that they cannot be tested at all (redundant)*
Generating Report  Reading SSBDD-model file c17.agm... OK  Reading test patterns file c17.tst... OK  Untestable faults:    ------------------------  Total of 0 faults untestable

 
 

prompt> report -table c17		*shows the fault table*
Generating Report  Reading SSBDD-model file c17.agm... OK  Reading test patterns file c17.tst... OK  Fault table report:
x3 x4 g2>inp2 g3>inp1 x2 x5 g4>inp2 g3>inp2 g5>inp1 g1>inp1 x1	: 01X0  : 1XX0  : X1X0  : X0X1  : X01X  : 0X1X  : 0XX1  : X100  : X10X  : 0XX0  : 0XX0	*the first column corresponds to the the first vector* *the second corresponds to the second* *the third to the third and the fourth to the fourth* *the "0" stands for testable s-a-0 by the* *corresponding vector at the corresponding node* *the "1" stands for s-a-1 and "X" if nothing is tested*

 

prompt> report -progress c17	*shows how the fault coverage incrementally* *grows with each test vector*
Generating Report  Reading SSBDD-model file c17.agm... OK  Reading test patterns file c17.tst... OK  Coverage progress report:
Pattern 1: coverage 27.272727 % (6/22)  Pattern 2: coverage 54.545455 % (12/22)  Pattern 3: coverage 72.727273 % (16/22)  Pattern 4: coverage 90.909091 % (20/22)	*the first vector covers 6 out of 22 faults which gives 27.27%* *second one covers 6 faults more and the coverage grows* *4 new faults are tested here increasing the cover to 72.73%* *the 4 vectors alltogether cover 90.91% of all the faults*

Last update: 23 October, 2002 by Artur Jutman