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synopsis ATPG help!!!!!QQ

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Junior Member level 1
May 22, 2001
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Any one can help me!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!i appreciate very much!!!!!!!!!!!
when I run the DC to gen the test pattern in my design, tools shows the fault coverage is zero..........following is my cmd and message...

1. ) create_test_patterns -output test.vdb \
-backtrack_effort high \
-compaction_effort high \
-max_random_patterns 100 Combinational Test Pattern Generation starts:

Non-collapsed Collapsed
No. of detected faults 0 0
No. of abandoned faults 0 0
No. of tied faults 0 0
No. of redundant faults 0 0
No. of untested faults 26952 17318
Total no. of faults 26952 17318
Fault coverage 0.00 0.00

No. of test patterns 0

Test Generation Time (CPU) 0.20 sec
Information: No tests generated - conflicting signal requirements in design. Use the 'report_test -atpg_conflicts' command for more information. (TEST-208)

2. ) when I use the 'report_test -atpg_conflicts' , it show that there are 6 inout port in my design....but these birdirational port are necessary and I wish these ports to output my test data.....

3. ) In DC, it may "not" gen the test pattern if the design has the bidirectional port in it, really?
If it can gen the test pattern, how could i do to set the command? and the the test data can be sent out form these bidirection port?
and the fault coverage is not "ZERO!"


Hi Jazz,
It is very hard to analyze the problem with this information,
please try the following commands
and verify if you have "test design rule violation" into your design

set_test_methodology full_scan
set_scan_style multiplexed_flip_flop
check_test -verbose

Hi, gnomix , tks for your reply, ......

ya, there are some design rule viloation" in my design, but the scan _chanin is insert successful for the syncronous clock, and when I replace the bidirection port cell to the output cell, the tools can gen the test_pattern successfuly,, i doult that, it is the bidirectional cell problem, which cause the atpg tool can not gen the test pattern.........


and the reference manual of DC says that, the bidirectional cell or tristate may cause the low fault coverage or may be fail to gen the test patterns........


and I have the atpg cobflicts show that........

report_test -atpg_conflicts
Warning: Design 'test' has '4' unresolved references. For more detailed information, use the "link" command. (UID-341)

Report : test
Design : test
Version: 2000.05-1
Date : Wed May 7 17:57:54 2003

Design Object Conflict Reason
------------- ---------------
MP06 (Net) three-state contention/float



try to force (with the Test_Enable pad) the bidirectional in output mode and set true the variable atpg_bidirect_output_only (normally false)

atpg_bidirect_output_only = "true"

I don't know if this way can solve your problem , normally I following a most complex flow.


HI, gnomix:
Tks very much for your suggestion, I will try it!
Appreciate very much1 ^^

BTW, what the complex flow you folow for the test_compiler?


Hi, gnomix!!!!!!!!!!!11
Tks very very very very very.....................MUCH to you!

It can works now!

tks you!!!!!!!!!!!!!!!!!!!!!!!!!!1^^
but what flow do you follow to do the test_compiler????


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