UT Institute of Computer Science Graduation Theses Registry

Name

Mehrdad Bagheri

Abstract

The goal of this thesis is to bring support of mixed-critical applications to system-level design flow of dependable Network-on-chip-based (NoC-based) multiprocessor systems. NoC-based multiprocessor technology is emerging as the next-generation platform for cyber-physical-systems. At the same time, there is a motivation to adopt mixed-critical applications in such systems. Therefore, there is a need for a suitable system-level design (SLD) framework which also supports development of mixed-critical systems. We choose a recent SLD framework for NoC-based systems and enhance it to support mixed-critical applications. This framework performs modeling rather than simulation which makes it much faster than a NoC simulator. At the same time it generates cycle accurate schedules to be verified against the simulators. However, this SLD framework does not support mixed-critical applications. We develop our mixed-critical solution on top of this SLD framework. We intend to deal with the problem of resource under-utilization which is associated with mixed-criticality and affects system performance. At the same time we need to maintain dependability and predictability of the critical parts of the application. In our solution, we develop an application model which supports mixed-criticality for both tasks and messages. Furthermore, we develop a mixed-critical fault-tolerance for computation and communication scheduling of our SLD framework. Our mixed-critical approach identifies tasks and messages of different criticality. In order to tackle the problem of under-utilization, the fault-tolerance in our approach is worst-case scenario for critical parts whereas it is average-case scenario for non-critical parts and it considers both design-time estimation and run-time condition in terms of fault occurrence. We have run several experiments on various applications and with different design settings in order to evaluate our solution. With the solution developed in this thesis, we have successfully enhanced our SLD flow to handle and schedule dependable mixed-critical applications. We have addressed the resource under-utilization problem and achieved performance improvements in the generated schedules.

Graduation Thesis language

English

Graduation Thesis type

Master - Software Engineering

Supervisor(s)

Gert Jervan

Defence year

2013