The Design, Analysis, & Application Of Multi-Modal Real-Time Embedded Systems

THE DESIGN, ANALYSIS, & APPLICATION OF MULTI-MODAL REAL-TIMEEMBEDDED SYSTEMSbyMASUD AHMEDDecember 2014 Advisor: Dr. Nathan FisherMajor: Computer ScienceDegree: Doctor of Philosophy For many hand-held computing devices (e.g., smartphones, tablet computers, and GPS re-ceivers), multiple operational modes are preferred because of their flexibility. In addition to theirdesignated purposes, some of these devices provide a platform for different types of services,which include rendering of high-quality multimedia. Upon such devices, temporal isolationamong co-executing applications is very important to ensure that each application receives anacceptable level of quality-of-service. In order to provide strong guarantees on services, mul-timedia applications and real-time control systems maintain timing constraints in the form ofdeadlines for recurring tasks. A flexible real-time multi-modal system will ideally provide sys-tem designers the option to change both resource-level modes and application-level modes. Ex-isting schedulability analysis for a real-time multi-modal system (MMS) with software/hardwaremodes are computationally intractable. In addition, a fast schedulability analysis is desirable ina design-space exploration that determines the “best” parameters of a multi-modal system byrepeated application of the MMS schedulability analysis. The thesis of this dissertation is: The determination of resource parameters with guaranteed schedulability for real-time systems that may change computational requirements over time is expensive interms of runtime. However, decoupling schedulability analysis from determining the