VAST: Virtualization-Assisted Concurrent Autonomous Self-Test

Abstract

Virtualization-Assisted concurrent, autonomous Self-Test, or VAST, enables a multi-/many-core system to test itself, concurrently during normal operation, without any user-visible downtime. Such on-line self-test is required for large-scale robust systems with built-in support for circuit failure prediction, failure detection, diagnosis, and self-healing. The main idea behind VAST is hardware and software co-design of on-line self-test features in a multi-/many-core system through integration of: 1. multi-/many-core architecture, 2. virtualization software, and, 3. special self-test techniques such as BIST (Built-In Self-Test) or CASP (Concurrent Autonomous chip self-test using Stored Patterns). As a result, optimized trade-offs in system design complexity, system performance and power impact, and test thoroughness are possible. Experimental results from an actual multi-core system demonstrate that: 1. VAST is practical and effective; and, 2. Special VAST-supported self-test policies enable extremely thorough on-line self-test with very small performance impact.