editor's blog
Subscribe Now

Describing User-Defined Faults

In today’s article on cell-aware fault modeling, we described how specific layout-dependent faults can be accounted for in the test suite, increasing the test coverage beyond what stuck-at modeling provides and yet keeping the vector count down below what gate-exhaustive modeling would require.

But there has to be some way of defining these specific “user-defined” faults so that the test generation program can include them in the test suite.

Mentor devised their so-called “User-Defined Fault Model”, or UDFM, language to handle this. It’s a human-readable and -writable format, and you can use it to define both static and transition faults. This allows you to describe specific custom faults manually if you wish, although, as described in the article, it would be written out automatically by the tools.

As an example, the following would define the four possible alternative tests for the static fault caused by the low-resistance bridge example in the article:

Fault “Bridge-R4” {

       Test {StaticFault “Z”=0; Condition “S0”=0,”S1”=0,”D0”=0,”D1”=-,”D2”=1}

       Test {StaticFault “Z”=0; Condition “S0”=1,”S1”=0,”D0”=-,”D1”=0,”D2”=1}

       Test {StaticFault “Z”=0; Condition “S0”=0,”S1”=1,”D0”=1,”D1”=-,”D2”=0}

       Test {StaticFault “Z”=0; Condition “S0”=1,”S1”=1,”D0”=-,”D1”=1,”D2”=0}


Leave a Reply

featured blogs
Dec 13, 2018
https://youtu.be/SxGTX1reCVw The three highlighted posts for August were: Diwali, the Hindu Festival of Lights...and Photonics, the Silicon Festival of Light Inside Google's TPU Mechanical,... [[ Click on the title to access the full blog on the Cadence Community site. ...
Dec 13, 2018
In November, we continued our mobile updates to the website, released a couple of new content experiences, and made placing sample requests even easier. Read more below on these and the rest of the major updates to Samtec.com for November 2018. Continued Improvements to our M...
Dec 10, 2018
With Apple'€™s '€œWearable'€ category of sales setting a new record this September with growth over 50%, and FitBit seeing growth in both trackers......
Nov 14, 2018
  People of a certain age, who mindfully lived through the early microcomputer revolution during the first half of the 1970s, know about Bill Godbout. He was that guy who sent out crudely photocopied parts catalogs for all kinds of electronic components, sold from a Quon...