An Overview of Worst Case Execution Time (WCET)Analysis

The purpose of Worst-Case Execution Time (WCET)analysis is to provide a-priori information about the worst possible execution time of a program or piece of a program before using them in a system. When designing and verifying real-time systems, WCET estimates can be used to perform scheduling and schedulability analysis, to determine whether performance goals are met for periodic tasks, to check that interrupts have sufficiently short reaction time, to find performance bottlenecks, and so on. In this paper we overview the analysis methods of WCET analysis, describe its components, and summarize the analysi methods of program flow fact analysis in WCET analysis. We point out the problem in program flow fact analysis and the research hot spot in WCET analysis.