ATPG for Timing Errors in Globally Asynchronous Locally Synchronous Systems

Abstract

Globally Asynchronous, Locally Synchronous (GALS) systems are now commonplace in many cost-critical and life-critical applications, thus motivating the need for a systematic approach to verify functionality. The complexity of the verification problem for large heterogeneous GALS systems necessitates the development of simulation-based validation approaches to uniformly validate hardware, software, and their interaction. GALS systems are comprised of several processes which may be mapped to different hardware and software components and communicate through asynchronous interfaces. Communication between these processes must be verified to ensure that the system is working correctly. Previous work focuses on checking the correctness of individual processes rather than communication between multiple processes. Timing errors may cause a signal to have an incorrect value for a short time period. Timing errors can cause a problem in GALS systems if the value of a signal with a timing error is used while is has an incorrect value. This paper presents an automatic test pattern generation (ATPG) tool to generate tests for timing-induced functional errors.