Title
X-Tolerant Tunable Compactor for In-System Test
Abstract
There is a growing number of integrated circuits that deploy hybrid test schemes combining on-chip test compression with logic BIST, with both techniques working synergistically to deliver high quality tests. As their architectural differences are gradually blurring, and both schemes efficiently share test logic, they become more vulnerable to unknown (X) states whose sources vary from uninitialized memory elements to unwrapped-for-test analog modules. Typically, X values degrade test results, and thus test response compaction schemes must be duly protected. This paper presents maXpress – an X-tolerant programmable compactor deploying a new scan chain selection mechanism capable of completely (as required by many in-system test applications) masking X states within redefinable groups of scan chains and designated scan shift cycles. In addition to the new architecture, the paper proposes an algorithm to automate maXpress control settings based on scan chain selection rules deployed to suppress X states. Experimental results obtained for a variety of industrial designs show feasibility and efficiency of the proposed scheme altogether with actual impact of X-masking on a resultant test coverage and test pattern counts.
Year
DOI
Venue
2020
10.1109/ITC44778.2020.9325266
2020 IEEE International Test Conference (ITC)
Keywords
DocType
ISSN
built-in self-test,embedded-test,scan-based testing,test application time,unknown states,X-masking
Conference
1089-3539
ISBN
Citations 
PageRank 
978-1-7281-9114-0
1
0.35
References 
Authors
0
7
Name
Order
Citations
PageRank
Yingdi Liu182.51
Sylwester Milewski233.12
Grzegorz Mrugalski350135.90
Nilanjan Mukherjee410.35
Janusz Rajski52460201.28
Jerzy Tyszer683874.98
Bartosz Wldarczak710.35