IEEE 1588 is a standard for precise clock synchronization for networked measurement and control systems in LAN environment. This paper presents the design and implementation of two IEEE 1588 prototypes for wireless LAN (WLAN). The first one is implemented using a Linux PC platform and a standard IEEE 802.11 WLAN with modifications to the network device driver. The second prototype is implemented using an embedded WLAN development board that implements the synchronization functionality using an embedded processor with programmable logic device (PLD) circuits. The measured results show that 1.1 ns average clock offset can be reached on HW based implementation, while Linux PC network driver enables 660 ns with a standard WLAN. Although WLAN is an extremely difficult environment for the synchronization, the results achieved with the prototype are fully comparable to those achieved with wired LAN implementations

Software and hardware prototypes of the IEEE 1588 precision time protocol on wireless LAN

The unified modeling language (UML) 2.0 is emerging in the area of embedded system design. This paper presents a new UML 2.0 profile - called TUT-profile - that introduces a set of stereotypes and design rules for an application, platform, and mapping. The profile classifies different application and platform components, and enables their parameterization. The TUT-profile concentrates on the structure of an application and platform, and utilizes standard UML 2.0 for the behavioral modeling. The application is seen as a set of active classes with an internal behavior. Correspondingly, the platform is seen as a component library with a parameterized presentation in UML 2.0 for each library component.

/pdf/uml-2-0-profile-for-embedded-system-design-54xehami9r.pdf

UML 2.0 Profile for Embedded System Design

SystemC has become a very popular standardized language for the modeling of system-on-chip (SoC) devices. However, due to the ever increasing complexity of SoC designs, the ever longer simulation times affect SoC exploration potential and time-to-market. In order to reduce these times, we have developed a parallel SystemC kernel. Because the SystemC semantics require a high level of synchronization which can dramatically affect the performance gains, we investigate in this paper some ways to reduce the synchronization overheads. We validate then our approaches against an academic design model and a real, industrial application.

Relaxing Synchronization in a Parallel SystemC Kernel

This paper presents the design and full prototype implementation of a configurable multiprocessor platform that supports distributed execution of applications described in UML 2.0. The platform is comprised of multiple Altera Nios II softcore processors and custom hardware accelerators connected by the Heterogeneous IP Block Interconnection (HIBI) communication architecture. Each processor has a local copy of eCos real-time operating system for the scheduling of multiple application threads. The mapping of a UML application into the proposed platform is presented by distributing a WLAN medium access control protocol onto multiple CPUs. The experiments performed on FPGA show that our approach raises system design to a new level. To our knowledge, this is the first real implementation combining a high-level design flow with a synthesizable platform.

/pdf/configurable-multiprocessor-platform-with-rtos-for-2w3l8njaz2.pdf

Configurable Multiprocessor Platform with RTOS for Distributed Execution of UML 2.0 Designed Applications

The engineering of communication protocols is quite difficult and a complex task, as it demands good experience in the field of protocol and system design, implementation, testing, optimization and maintenance of such protocols. In most cases, these protocols are described using informal techniques like informal textual documentations, graphical description techniques, and structural analysis and design. As proven in practice, these lead to ambiguous definitions and lack of definitions because completeness, and consistency cannot be proved. The advent of Unified Modeling Language version 2.0 (UML 2.0) along with its UML Testing Profile (U2TP)in the recent years, promises to be a major break through in the field of formal description techniques. Thus, this work evaluates the suitability of UML 2.0 combined with its Testing Profile for engineering communication protocols using a case study. For experimental case study, this work uses a simple and the most commonly known INRES (Initiator - Responder) protocol. This book is expected to serve as a good starting point for learning UML 2.0 and protocol engineering.

Industrial Communication Protocol Engineering Using UML 2.0

This paper evaluates the suitability of the new Unified Modelling Language (UML) 2.0 for the design and implementation of embedded wireless local area network (WLAN) protocols. UML 2.0 introduces several new features and improvements to semantics, diagram types, and notations of the language. Behaviour in UML 2.0 can be described accurately and precisely, which enables automatic source code (C/C++ for example) generation for creating executable models. A medium access control (MAC) protocol called TUTMAC was designed and implemented with UML 2.0, and integrated into a hardware platform. The implementation with UML 2.0 reached adequate performance for the protocol with time-critical functionality on the target platform.

UML 2.0 implementation of an embedded WLAN protocol

This paper presents parallelization of System-on-Chip (SoC) simulation over a network of computers. A custom C-language-based SoC exploration and simulation tool, Discrete Time Network Simulator (DTNS), is used to examine the problem. Parallelization is implemented with either CORBA or TCP/IP sockets. The distributed DTNS architecture facilitates the analysis of computation requirements for reasonable distribution. The minimum execution time per distributed process for the parallelization to be profitable is 1.2ms with CORBA and 0.4ms with TCP/IP implementation. These results are based on our networked PCs running the Linux operating system. The same network is used to evaluate this distribution method in case of video encoder SoC simulation.

V. Helminen

Papers

UML 2.0 implementation of an embedded WLAN protocol

Distributing SoC simulations over a network of computers