Choosing the most efficient test patterns and setting coverage targets has always been a challenge and becomes even more daunting with the addition of new types of patterns. DFT teams can spend years establishing ATPG targets—like a coverage goal, pattern size, or some other metric—just for stuck-at and transition fault models. Targets need to be adjusted for a new technology node when new important fault models are introduced. How do companies decide what targets to set? If you want to apply a sample of patterns aimed at a new fault model, which patterns are best to try?
The answer lies in using physical layout information to calculate the effectiveness of each test pattern based on the likelihood of particular physical defects occurring. We can determine this through total critical area (TCA) calculations.
For example, consider targeting a test coverage for all potential bridge faults—this could be a huge list. You might achieve 99% detection of all bridge faults but miss hundreds of the most likely bridges. It is more effective to choose the subset of bridges that is most likely to occur.
Learn more in this live, one-hour, online seminar Tessent DFT – A new method to find and optimize the most effective test patterns presented by Ron Press, director of technology enablement at Siemens EDA.
When: September 9, 2021, at 9:00 AM US/Pacific
Where: Live, online presentation, and Q&A with the expert
Cost: An hour of your time
The seminar covers:
- How critical area can optimize the selection of the most effective patterns from various pattern sets
- An automated simple process to determine the best patterns to apply when truncating
- Silicon value seen with some new types of patterns
- How to apply the patterns that are most like to detect defects first
You may also find this ATPG paper of interest available to download here: