Regarding DFT scan couarage.

[vijaymails]

hi

Can anybody tell me suggestion regarding scan courage. coverage couldnot meet the expectation . is mainly from which faults.(Is it mainly )because of bridging.

 

[dft_guy]

If you are talking about scan "courage", I can offer support: I know you can muster the courage to implement scan... ;-)

If you are talking about scan "coverage", well then there may be many reasons your coverage did not meet expectations.

1) Are you speaking of the coverage given to you by the ATPG tool? It's not good?
or
2) Are you saying that you thought you had good ATPG coverage, but you're getting too many returned devices?

If 1) then you need to read your coverage report, and it will tell you what kinds of faults are not being covered.

If 2) then you have an incomplete test program, and assuming you have a high "stuck at" fault coverage set of ATPG patterns, you're missing something else, like at-speed patterns, test for parametric faults (IDDQ, leakage, levels, etc).

Nothing more to say without more detail...

John
DFT Digest