Performance estimation of embedded software with instruction cache modeling

Abstract

Embedded systems generally interact with the outside world. Thus, some real-time constraints may be imposed on the system design. Verification of these constraints requires computing a tight upper bound on the worst case execution time (WCET) of a hardware/software system. The problem of bounding WCET is particularly difficult on modern processors, which use cache-based memory systems that vary memory access time significantly. This must be accurately modeled in order to tightly bound WCET. Existing approaches either search all possible program paths, an intractable problem, or they use pessimistic assumptions to limit the search space. In this paper we present afar more effective and accurate method for modeling instruction cache activity and computing a tight bound on WCET. It is implemented in the program cinderella. We present some preliminary results of using this tool on sample embedded programs.