Maintenance Consideration for Long Life Cycle Embedded System

Abstract:      In this thesis, the work presented is in relation to consideration to the maintenance of a long life cycle embedded system. Various issues can present problems for maintaining a long life cycle embedded system, such as component obsolescence and IP (intellectual property) portability.      For products including automotive, avionics, military application etc., the desired life cycles for these systems are many times longer than the obsolescence cycle for the electronic components used in the systems. The maintainability is analyzed in relation to long life cycle embedded systems for different design technologies. FPGA platform solutions are proposed in order to ease the system maintenance. Different platform cases are evaluated by analyzing the essence of each case and the consequences of different risk scenarios during system maintenance. This has shown that an FPGA platform with a vendor and device independent soft IP has the highest maintainability.A mathematic model of obsolescence management for long life cycle embedded system maintenance is presented. This model can estimate the minimum management costs for the different system architecture and this consists of two parts. The first is to generate a graph in Matlab which is in the form of state transfer diagram. A segments table is then output from Matlab for further optimization. The second part is to find the lowest cost in the state transfer diagram, which can be viewed as a transshipment problem. Linear programming is used to calculate the minimized management cost and schedule, which is solved by Lingo. A simple Controller Area Network (CAN) controller system case study is shown in order to apply this model. The model is validated by a set of synthetic and experimentally selected values. The results provided by this are a minimized management cost and an optimized management time schedule. Test experiments of the maintenance cost responding to the interest rate and unit cost are implemented. The responses from the experiments meet our expectations.      The reuse of predefined IP can shorten development times and assist the designer to meet time-to-market (TTM) requirements. System migration between devices is unavoidable, especially when it has a long life cycle expectation, so IP portability becomes an important issue for system maintenance. An M-JPEG decoder case study is presented in the thesis. The lack of any clear separation between computation and communication is shown to limit the IP’s portability with respect to different communication interfaces. A methodology is proposed to ease the interface modification and interface reuse, thus to increase the portability of an IP. Technology and tool dependent firmware IP components are also shown to limit the IP portability with respect to development tools and FPGA vendors.