Hardware-Software Co-Design of Real-Time Systems
Project no: #2
Zebo Peng, Petru Eles
Linköping University, Department of Computer and Information Science, Embedded Systems Laboratory (ESLAB)
Application as pdf, ps, supported by Volvo Technological Development Corporation.
Mobility application okt 98.
Support: 1 PhD student for 2 years decided 98-01-13.
Mobility support: 30 kkr decided 98-10-06.
Start 98-03-01 with Paul Pop as PhD student.
Reports: In ARTES annual report for 97-98, at ARTES RT-grad student day 99, Status report 990813 as pdf, ps. Second-year-report given at summershool 2000 and supplemented with industry letter.
Local web page:

Industry contact

Henrik Lönn
Volvo Technological Development Corporation
Projects: Hardware/Software Codesign of Real-Time Systems


This project deals with the development of techniques and tools for hardware/software codesign of real-time systems. In particular we will concentrate on methods for the architecture selection problem. This entails formulating a hardware/software architecture model, developing a mapping strategy to map a real-time system specification into such an architecture, and designing techniques for the analysis of a given design based on a given architecture and some scheduling methods. We will also study the problem of how to use the analysis results to guide the modification of the given architecture, in order to allow the designers to quickly explore the different design alternatives and find a cost-effective solution of mixed hardware/software implementations of a given real-time system. The research work is being done in close cooperation with the industry, especially those in the automotive electronics area. We will use examples from the industrial partners to demonstrate the advantages of the developed methods.


In order to capture both the data-flow and the control aspects of a given application, a conditional process graph representation has been defined by us earlier. Algorithms for static, time-driven scheduling of conditional process graphs on distributed systems have been developed and implemented. We have extended this approach to include systems with priority based preemptive scheduling. This is important because many control oriented applications are event driven by their nature. Our main contribution in this area is the development of an efficient scheduling technique, taking into account both data and control dependency. The Time-Triggered Protocol (TTP) is becoming more and more accepted as the communication infrastructure for safety-critical automotive applications. In this context we have extended our scheduling algorithms, considering TTP as the particular protocol for inter-processor communication. At the same time, we have developed algorithms in order to optimize the parameters of the protocol such that specific requirements and constraints imposed by the application are met. We have also investigated schedulability aspects of applications implemented with priority-based preemptive scheduling, on top of the TTP-based communication support. In this context, we have developed algorithms for optimization of protocol parameters. The particular case study is based on a vehicle cruise controller.

Paul Pop will defend his Licenciate thesis with the title "Scheduling and Communication Synthesis for Distributed Real-Time Systems" in June 2000.


Joint graduate courses with ECSEL in Linköping
  • Advanced issues in computer architectures
  • Design of embedded real-time systems


  1. P. Eles, K. Kuchcinski, Z. Peng, A. Doboli and P. Pop, "Process Scheduling for Performance Estimation and Synthesis of Hardware/Software Systems," Proc. Euromicro'98 Workshop on Digital System Design: Architectures, Methods and Tools, Västerås, Aug. 25-27, 1998, pp. 168-175.
  2. P. Pop, P. Eles, and Z. Peng, "Scheduling Driven Partitioning of Heterogeneous Embedded Systems," Proc. 7th Swedish Workshop on Computer Systems Architecture, Göteborg, June 3-5, 1998, pp. 99-102.
  3. P. Pop, P. Eles, Z. Peng, Communication Scheduling for Time-Triggered Systems, 11th Euromicro Conference on Real-Time Systems , York, England, June 9-11, 1999 (Work in Progress Proceedings)
  4. P. Pop, P. Eles, Z. Peng, Scheduling with Optimized Communication for Time-Triggered Embedded Systems, 7th International Workshop on Hardware/Software Codesign Rome, Italy, May 3-5,1999, pages 178-182
  5. P. Pop, P. Eles, Z. Peng, An Improved Scheduling Technique for Time-Triggered Embedded Systems, 25th Euromicro Conference, Milan, Italy, September 8-10, 1999, pages 303-310
  6. P. Pop, P. Eles, Z. Peng, Schedulability-Driven Communication Synthesis for Time Triggered Embedded Systems, 6th International Conference on Real-Time Computing Systems and Applications, (RTCSA'99), Hong Kong, December 13-15, 1999, pages 287-294
  7. Paul Pop, Petru Eles, Zebo Peng. Schedulability Analysis for Systems with Data and Control Dependencies. Euromicro Conference on Real-Time Systems, Stockholm, 2000.
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