30,808 research outputs found
Dynamic Memory Allocation in TinyOS
TĂĄto prĂĄce porovnĂĄva po strĂĄnce teoretickĂ© i praktickĂ© rĆŻznĂ© zpĆŻsoby dynamickĂ©ho pĆidÄlovĂĄnĂ pamÄti v operaÄnĂm systĂ©mu TinyOS urÄenĂ©m pro jednoduchĂĄ programovatelnĂĄ zaĆĂzenĂ. U jednotlivĂœch zpĆŻsobĆŻ byly sledovĂĄny rĆŻznĂ© aspekty. Mezi hlavnĂ patĆĂ efektivita vyuĆŸitĂ zdrojĆŻ, rychlost alokace a pouĆŸitelnost z programĂĄtorskĂ©ho hlediska. PrĂĄce zĂĄroveĆ rozĆĄiĆuje moĆŸnosti alokace pamÄti na externĂ flash pamÄĆ„. Ve struÄnoti takĂ© vysvÄtluje princIpy dynamickĂ© alokace pamÄti a jejĂ aplikace v prostĆedĂ jednoduchĂœch programovatelnĂœch zaĆĂzenĂ s omezenĂœmi zdroji.This thesis aims for a theoretical and practical comparison of two different approaches to dynamic memory management in TinyOS operating system designated for simple programmable devices. For each of the approaches we were observing different aspects, among others the effectivity of usage of resources, allocation speed and usability from the programmers point of view. Thesis also extends the capabilities of dynamic allocation onto external flash memory. It shortly explains the principles behind dynamic memory allocation and it's application in the area of simple programmable devices with limited resources.
The Design of a System Architecture for Mobile Multimedia Computers
This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile Digital Companion, energy management plays a crucial role in the architecture. As the Companion must remain usable in a variety of environments, it has to be flexible and adaptable to various operating conditions. The Mobile Digital Companion has an unconventional architecture that saves energy by using system decomposition at different levels of the architecture and exploits locality of reference with dedicated, optimised modules. The approach is based on dedicated functionality and the extensive use of energy reduction techniques at all levels of system design. The system has an architecture with a general-purpose processor accompanied by a set of heterogeneous autonomous programmable modules, each providing an energy efficient implementation of dedicated tasks. A reconfigurable internal communication network switch exploits locality of reference and eliminates wasteful data copies
Octopus - an energy-efficient architecture for wireless multimedia systems
Multimedia computing and mobile computing are two trends that will lead to a new application domain in the near future. However, the technological challenges to establishing this paradigm of computing are non-trivial. Personal mobile computing offers a vision of the future with a much richer and more exciting set of architecture research challenges than extrapolations of the current desktop architectures. In particular, these devices will have limited battery resources, will handle diverse data types, and will operate in environments that are insecure, dynamic and which vary significantly in time and location. The approach we made to achieve such a system is to use autonomous, adaptable modules, interconnected by a switch rather than by a bus, and to offload as much as work as possible from the CPU to programmable modules that is placed in the data streams. A reconfigurable internal communication network switch called Octopus exploits locality of reference and eliminates wasteful data copies
The potential of programmable logic in the middle: cache bleaching
Consolidating hard real-time systems onto modern multi-core Systems-on-Chip (SoC) is an open challenge. The extensive sharing of hardware resources at the memory hierarchy raises important unpredictability concerns. The problem is exacerbated as more computationally demanding workload is expected to be handled with real-time guarantees in next-generation Cyber-Physical Systems (CPS). A large body of works has approached the problem by proposing novel hardware re-designs, and by proposing software-only solutions to mitigate performance interference. Strong from the observation that unpredictability arises from a lack of fine-grained control over the behavior of shared hardware components, we outline a promising new resource management approach. We demonstrate that it is possible to introduce Programmable Logic In-the-Middle (PLIM) between a traditional multi-core processor and main memory. This provides the unique capability of manipulating individual memory transactions. We propose a proof-of-concept system implementation of PLIM modules on a commercial multi-core SoC. The PLIM approach is then leveraged to solve long-standing issues with cache coloring. Thanks to PLIM, colored sparse addresses can be re-compacted in main memory. This is the base principle behind the technique we call Cache Bleaching. We evaluate our design on real applications and propose hypervisor-level adaptations to showcase the potential of the PLIM approach.Accepted manuscrip
Design of a Hybrid Modular Switch
Network Function Virtualization (NFV) shed new light for the design,
deployment, and management of cloud networks. Many network functions such as
firewalls, load balancers, and intrusion detection systems can be virtualized
by servers. However, network operators often have to sacrifice programmability
in order to achieve high throughput, especially at networks' edge where complex
network functions are required.
Here, we design, implement, and evaluate Hybrid Modular Switch (HyMoS). The
hybrid hardware/software switch is designed to meet requirements for modern-day
NFV applications in providing high-throughput, with a high degree of
programmability. HyMoS utilizes P4-compatible Network Interface Cards (NICs),
PCI Express interface and CPU to act as line cards, switch fabric, and fabric
controller respectively. In our implementation of HyMos, PCI Express interface
is turned into a non-blocking switch fabric with a throughput of hundreds of
Gigabits per second.
Compared to existing NFV infrastructure, HyMoS offers modularity in hardware
and software as well as a higher degree of programmability by supporting a
superset of P4 language
Reconfigurable Mobile Multimedia Systems
This paper discusses reconfigurability issues in lowpower hand-held multimedia systems, with particular emphasis on energy conservation. We claim that a radical new approach has to be taken in order to fulfill the requirements - in terms of processing power and energy consumption - of future mobile applications. A reconfigurable systems-architecture in combination with a QoS driven operating system is introduced that can deal with the inherent dynamics of a mobile system. We present the preliminary results of studies we have done on reconfiguration in hand-held mobile computers: by having reconfigurable media streams, by using reconfigurable processing modules and by migrating functions
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