Accurate Timed RTOS Model for Transaction Level Modeling

Abstract-In this paper, we present an accurate timed RTOS model within transaction level models (TLMs). Our RTOS model, implemented on top of system level design language (SLDL), incorporates two key features: RTOS behavior model and RTOS overhead model. The RTOS behavior model provides dynamic scheduling, inter-process communication (IPC), and external communication for timing annotated user applications. While the RTOS behavior model is running, all RTOS events, such as context switch and interrupt handling, are passed to RTOS overhead model to adopt the overhead during system execution. Our RTOS overhead model has processor-and RTOS-specific precharacterized overhead information to provide cycle approximate estimation. We demonstrate the applicability of our model using a multi-core platform executing a JPEG encoder. Experimental results show that the proposed RTOS model provides the high accuracy, 7% off compared to on-board measurements while simulating at speeds close to the reference C code

Distributed real-time operating system (DRTOS) modeling in SpecC

System level design of an embedded computing system involves a multi-step process to refine the system from an abstract specification to an actual implementation by defining and modeling the system at various levels of abstraction. System level design supports evaluating and optimizing the system early in design exploration.;Embedded computing systems may consist of multiple processing elements, memories, I/O devices, sensors, and actors. The selection of processing elements includes instruction-set processors and custom hardware units, such as application specific integrated circuit (ASIC) and field programmable gate array (FPGA). Real-time operating systems (RTOS) have been used in embedded systems as an industry standard for years and can offer embedded systems the characteristics such as concurrency and time constraints. Some of the existing system level design languages, such as SpecC, provide the capability to model an embedded system including an RTOS for a single processor. However, there is a need to develop a distributed RTOS modeling mechanism as part of the system level design methodology due to the increasing number of processing elements in systems and to embedded platforms having multiple processors. A distributed RTOS (DRTOS) provides services such as multiprocessor tasks scheduling, interprocess communication, synchronization, and distributed mutual exclusion, etc.;In this thesis, we develop a DRTOS model as the extension of the existing SpecC single RTOS model to provide basic functionalities of a DRTOS implementation, and present the refinement methodology for using our DRTOS model during system level synthesis. The DRTOS model and refinement process are demonstrated in the SpecC SCE environment. The capabilities and limitations of the DRTOS modeling approach are presented

A component-oriented programming framework for developing embedded mobile robot software using PECOS model

A practical framework for component-based software engineering of embedded real-time systems, particularly for autonomous mobile robot embedded software development using PECOS component model is proposed The main features of this framework are: (1) use graphical representation for components definition and composition; (2) target C language for optimal code generation with small micro-controller; and (3) does not requires run-time support except for real-time kernel. Real-time implementation indicates that, the PECOS component model together with the proposed framework is suitable for resource constrained embedded systems

Industrial Application of a Partitioning Scheduler to Support Mixed Criticality Systems

The ever-growing complexity of safety-critical control systems continues to require evolution in control system design, architecture and implementation. At the same time the cost of developing such systems must be controlled and importantly quality must be maintained. This paper examines the application of Mixed Criticality System (MCS) research to a DAL-A aircraft engine Full Authority Digital Engine Control (FADEC) system which includes studying porting the control system\u27s software to a preemptive scheduler from a non-preemptive scheduler. The paper deals with three key challenges as part of the technology transitions. Firstly, how to provide an equivalent level of fault isolation to ARINC 653 without the restriction of strict temporal slicing between criticality levels. Secondly extending the current analysis for Adaptive Mixed Criticality (AMC) scheduling to include the overheads of the system. Finally the development of clustering algorithms that automatically group tasks into larger super-tasks to both reduce overheads whilst ensuring the timing requirements, including the important task transaction requirements, are met

Agglomerative Magnets and Informal Regulatory Networks: Electricity Market Design Convergence in the USA and Continental Europe

The absence of one broadly accepted design template for liberalised electricity markets induces regulatory competition and institutional diversity. Focussing on continental Europe and the USA, this analysis explores how agents and structures accelerate or impede the move to one standard market design in the electricity sector. It reveals that market design convergence in Europe is driven by the 'Florence Consensus,' a tripartite coalition between the European Commission fostering European integration and the internal market, informal regulatory networks between grid operators, standardisation authorities and regulators, who have been coordinating their actions in the 'Florence Forum,' and epistemic communities exemplified in the Florence School of Regulation. In contrast, the United States' Federal Energy Regulatory Commission lacks support among politicians, many states' public utility commissions, the neo-liberal intelligentsia and even industrial lobbying groups to effectively push for a standardised market design. However, design convergence in the USA may be induced by the gradual expansion of multi-state markets operated by regional transmission organisations.Electricity, Deregulation, Regulatory Competition, Policy Diffusion