High Quality Test Solutions for Secure Applications

Designs for secure applications such as smart cards and those used in the defense industry require security to ensure sensitive data is inaccessible to outside agents. Conversely, scan chains have been used for decades to improve access to internal logic for automatic tester equipment (ATE) so that devices can be tested efficiently and quickly. This conflict in requirements has forced many designers of secure applications to use logic BIST and sacrifice test quality in some cases, or perform deterministic scan test in very costly secure test environments. Contributing to these challenges are the ever-increasing requirements for high quality test and additional test requirements for fabrication processes at smaller geometries. In this paper, we will explore the techniques currently in use for testing devices designed for secure application and review the benefits and challenges of each available solution.