Jyotirmoy Saikia

Breaking the Test Application Time Barriers in Compression: Adaptive Scan-Cyclical (AS-C)

Scan compression technology innovation has broken out into solving the data volume problem keeping the test application time gains relatively constant over the generations of technologies. While data volume reductions are important there is a need to take the test application time gains to the next level as it has a direct impact to the cost of test. In this paper an enhancement to combinational compression is described that relies on increasing the encoding bandwidth for aggressive test application time targets. An architecture is described that adds very little area overhead to a combinational compression architecture by reusing the internal scan chains of the design for encoding bandwidth for a set of the test patterns.

Predicting Scan Compression IP Configurations for Better QoR

Scan compression technology is essentially IP that provides an interface between the scan-inputs/outputs and the internal scan chains. The IP configuration that is put into the design is based upon some user specified constraints that are related to the target compression and the available scan terminals. The configuration selected may or may not be the best suited for the design it is inserted in. Usually the compression IP can be configured in many different ways. Some configurations are better suited for particular designs than others. If one were able to predict the configuration of the compression IP to match the needs of the design then one would expect the best results from the compression technology. In this paper we describe a method to predict the optimum IP configuration for Adaptive Scan, which is a specific type of compression technology. The concepts and methodology discussed here are applicable to any compression scheme.