CPU Execution Time Analysis based on RISC-V ISA Simulators: A Survey

Multiple components affect the behavior of CPU execution tasks, mainly mutual exclusion during access to the shared resources and synchronous transmissions between tasks that require specific priorities. Referring to real-time task scheduling, the most important issues addressed are monitoring the deadline of the tasks, the probability of non-compliance with the deadline and ensuring that they are completed within the deadline imposed by the controlled system. This leads to the fact that a tasks set is feasible if the system has adequate resources to execute the tasks without losing any deadlines. To approach this challenge, this article addresses the feasibility analysis of runtime for real-time tasks to be performed in a virtual space before applying to a real embedded device. These processes take place offline, even before a system executes a set of tasks. In order to perform the feasibility analysis of the system, efforts are being made to provide virtual environments and simulators, such as the RISC-V ISA simulator and the WCET (Worst Case Execution Time) measurement, subsequently. These simulators have application-specific requirements, with their own advantages.