Real-time considerations for rugged embedded systems

This chapter introduces the characterizing aspects of embedded systems and discusses the specific features that a designer should address in an embedded system "rugged," i.e., able to operate reliably in harsh environments. The chapter addresses both the hardware and the less obvious software aspects. After presenting a current list of certifications for ruggedization, the chapters present a case study that focuses on the interaction of the hardware and software layers in reactive real-time system. In particular, it shows how the use of fast field programmable gate array prototyping could provide insights on unexpected factors that influence the performance and thus responsiveness to events of a scheduling algorithm for multiprocessor systems that manages both periodic, hard real-time task, and aperiodic tasks. The main lesson is that to make the system "rugged," a designer should consider these issues by, for example, overprovisioning resources and/or computation capabilities.