Scan Compression Is No Longer About Compression


Scan compression was introduced in the year 2000 and has seen rapid adoption. Nearly every design’s test methodology today implements this technology, which inserts compression logic in the scan path between the scan I/Os and the internal chains. In this article, we take a critical look at the technology to understand how scan compression has matured. The road to scan compression Since th... » read more

IC Test: Doing It At The Right Place At The Right Time


In the real world, we are slaves to our environment. The decisions we make are dependent on the resources available at any given time. In school, I remember coming up with a binary decision diagram (BDD) variable-ordering algorithm that relied on partial BDDs. Was that the best algorithm to determine the variable ordering of a BDD for a design? Probably not. However, it was easy to do as a coll... » read more

Unified Compression and LBIST in a Physically Aware Environment


Unified compression is a new approach that unifies scan compression and logic built-in self-test (LBIST). It leverages recent innovations from Cadence in physically-aware design for test (DFT) to solve routing congestion and area issues from traditional discrete approaches and delivers a confident path to high-quality test. On a sample design, area savings of 35–47%, and scan wirelength savin... » read more