US-Tunisia Cooperative Research: Analysis of Interrupt Latency Using Hybrid Machines

Wayne State University, Detroit MI

Investigators

Abstract

0213651 Lin Description: This award is for support of a cooperative project by Professor Feng Lin, Department of Electrical and Computer Engineering, Wayne State University, Detroit, Michigan and Dr. Nejib Ben Hadj-Alouane, Department of Applied Computer Sciences at the Ecole Nationale d' Sciences Informatique (ENSI) in Tunis, Tunisia. This project is to investigate the interrupt latency problem in software design. Most microprocessor/microcontroller systems contain sources of interrupt and interrupt service routines, which are software components executing in response to the assertion of an interrupt in hardware. Because the interrupt service routines execute on the same Central Processing Unit (CPU), they compete for the CPU and interfere with each other's latency requirements. Latency is defined as the delay between the assertion of the interrupt in hardware and the start of execution of the associated interrupt service routine. An important problem is whether a specific set of sources of interrupt and interrupt service routines can coexist in the same microprocessor/microcontroller software load without causing interrupt latency violations. The investigators plan to use a recently developed framework of hybrid machines to solve this problem. They will model sources of interrupt and interrupt service routines as hybrid machines. The main task of this project is to develop models for common microprocessor/microcontroller systems, efficient algorithms to check co-reachability in hybrid machines, efficient ways to represent hybrid machine models in programming languages such as C, and software tools that will help engineers to check interrupt latency violations in software and the how to eliminate the violations. Scope: The two scientists have collaborated and published jointly in 1994 and in 1997 while Dr. Hadj-Alouane was employed at Dow Chemicals Company and at the University of Michigan respectively. The model they propose in this project may result in important changes in practice for software design. The project will allow for visits by Dr. Lin to Tunisia and will encourage a mutually beneficial international collaboration between the Wayne State University and the ENSI in Tunisia. Funds for this project are provided by the Office of International Science and Engineering, the Division of Computer-Communications Research and Division of Experimental and Integrative Activities.