CASP: Concurrent Autonomous Chip Self-Test Using Stored Test Patterns

CASP, concurrent autonomous chip self-test using stored test patterns, is a special kind of self-test where a system tests itself concurrently during normal operation without any downtime visible to the end-user. CASP consists of two ideas: 1. Storage of very thorough test patterns in non-volatile memory; and, 2. Architectural and system-level support for autonomous testing of one or more cores in a multi-core system using stored patterns, concurrently with normal system operation, without bringing down the entire system. CASP enables design of robust systems with built-in features for circuit failure prediction, error detection, self-diagnosis and self-repair. Such systems are necessary to overcome major reliability challenges in scaled-CMOS technologies. Implementation of CASP in the OpenSPARC Tl multi-core processor demonstrates its effectiveness and practicality.