The Experts below are selected from a list of 159 Experts worldwide ranked by ideXlab platform

Wu Tiebin - One of the best experts on this subject based on the ideXlab platform.

  • single instruction multiple data simd based parallel fast fourier transform inverse fast fourier transform fft ifft butterfly operation method and simd based parallel fft ifft butterfly operation device in vector processor
    2014
    Co-Authors: Liu Hengzhu, Chen Ting, Zhang Jianfeng, Zhang Botao, Liu Dongpei, Zhou Li, Wu Tiebin
    Abstract:

    The invention discloses a single instruction multiple data (SIMD)-based parallel fast fourier transform/inverse fast fourier transform (FFT/IFFT) butterfly operation method and an SIMD-based parallel FFT/IFFT butterfly operation device in a vector processor. The method comprises the following steps: dividing N-point butterfly computation into a plurality of sections to execute, wherein each section comprises a plurality of independent butterfly operation groups; carrying out data shuffling by adopting a fixed mode and then multiplying with a corresponding proper complex coefficient in each stage of butterfly operation of each butterfly operation group; carrying out addition and subtraction on two adjacent data so as to realize shuffling of vector data, complex multiplication and butterfly operation by using a single instruction. The implementation method is simple, and the execution efficiency is high, and independent complex multiplication is not needed in the butterfly operation, and power consumption of the processor can be effectively reduced. The device comprises a vector Register file, a fixed mode shuffling network, a proper complex coefficient multiplier array, a butterfly operation array and an FFT/IFFT Control Register. Parallel butterfly operation can be achieved by orderly execution, the complexity of hardware and operation is lowered, and the expansion of the hardware can be further facilitated.

Andreas Herkersdorf - One of the best experts on this subject based on the ideXlab platform.

  • ARCS - SgInt: Safeguarding Interrupts for Hardware-Based I/O Virtualization for Mixed-Criticality Embedded Real-Time Systems Using Non Transparent Bridges
    Lecture Notes in Computer Science, 2015
    Co-Authors: Daniel Münch, Michael Paulitsch, Oliver Hanka, Andreas Herkersdorf
    Abstract:

    Safety critical systems and in particular higher functional integrated systems like mixed-criticality systems in avionics require a safeguarding that functionalities cannot interfere with each other. A notably underestimated issue are I/O devices and their (message-signaled) interrupts. Message-signaled interrupts are the omnipresent type of interrupts in modern serial high-speed I/O subsystems. These interrupts can be considered as small DMA write packets. If there is no safeguarding for interrupts, an I/O device associated with a distinct functionality can trigger any interrupt or manipulate any Control Register like triggering reset of all processing cores to provoke a complete system failure. This is a particular issue for available embedded processor architectures, since they do not provide adequate means for interrupt separation like an IOMMU with a granularity sufficient for interrupts.

Joseph Yiu - One of the best experts on this subject based on the ideXlab platform.

  • Cortex-M3 Programming
    The Definitive Guide to the ARM Cortex-M3 TI, 2010
    Co-Authors: Joseph Yiu
    Abstract:

    This chapter discusses the programming in the Cortex-M3 processor. The Cortex-M3 can be programmed using either assembler or C and because a lot of information on the way to do programming depends on the tool chain and silicon chips. C has the advantage of being portable and easier for implementing complex operations, compared to assembly language. Since it's a generic computer language, C does not specify how the processor is initialized. For these areas, tool chains can have different approaches. The best way to get started is to look at example codes. For users of ARM C compiler products such as RealView Development Suite (RVDS) or KEIL RealView MicroController Development Kit, a number of Cortex-M3 program examples are already included in the installation. Use of the C language can often speed up application development, but in many cases low-level system Control still requires assembly code. Most ARM C compilers allow including assembly code, called inline assembler. This code is often necessary for many projects. For the Cortex-M3, Embedded Assembler is useful for tasks such as accessing special Registers (MRS and MSR instructions; for example, setting up stack memory) or when it is necessary to use instructions that cannot be generated using C. When developing applications in C, it is recommended that one use the double word stack alignment function (configured by the STKALIGN bit in the NVIC Configuration Control Register).

  • Chapter 10 – Cortex-M3 Programming
    The Definitive Guide to the ARM Cortex-M3, 2007
    Co-Authors: Joseph Yiu
    Abstract:

    Publisher Summary This chapter discusses the programming in the Cortex-M3 processor. The Cortex-M3 can be programmed using either assembler or C and because a lot of information on the way to do programming depends on the tool chain and silicon chips. C has the advantage of being portable and easier for implementing complex operations, compared to assembly language. Since it's a generic computer language, C does not specify how the processor is initialized. For these areas, tool chains can have different approaches. The best way to get started is to look at example codes. For users of ARM C compiler products such as RealView Development Suite (RVDS) or KEIL RealView MicroController Development Kit, a number of Cortex-M3 program examples are already included in the installation. Use of the C language can often speed up application development, but in many cases low-level system Control still requires assembly code. Most ARM C compilers allow including assembly code, called inline assembler. This code is often necessary for many projects. For the Cortex-M3, Embedded Assembler is useful for tasks such as accessing special Registers (MRS and MSR instructions; for example, setting up stack memory) or when it is necessary to use instructions that cannot be generated using C. When developing applications in C, it is recommended that one use the double word stack alignment function (configured by the STKALIGN bit in the NVIC Configuration Control Register).

Liu Hengzhu - One of the best experts on this subject based on the ideXlab platform.

  • single instruction multiple data simd based parallel fast fourier transform inverse fast fourier transform fft ifft butterfly operation method and simd based parallel fft ifft butterfly operation device in vector processor
    2014
    Co-Authors: Liu Hengzhu, Chen Ting, Zhang Jianfeng, Zhang Botao, Liu Dongpei, Zhou Li, Wu Tiebin
    Abstract:

    The invention discloses a single instruction multiple data (SIMD)-based parallel fast fourier transform/inverse fast fourier transform (FFT/IFFT) butterfly operation method and an SIMD-based parallel FFT/IFFT butterfly operation device in a vector processor. The method comprises the following steps: dividing N-point butterfly computation into a plurality of sections to execute, wherein each section comprises a plurality of independent butterfly operation groups; carrying out data shuffling by adopting a fixed mode and then multiplying with a corresponding proper complex coefficient in each stage of butterfly operation of each butterfly operation group; carrying out addition and subtraction on two adjacent data so as to realize shuffling of vector data, complex multiplication and butterfly operation by using a single instruction. The implementation method is simple, and the execution efficiency is high, and independent complex multiplication is not needed in the butterfly operation, and power consumption of the processor can be effectively reduced. The device comprises a vector Register file, a fixed mode shuffling network, a proper complex coefficient multiplier array, a butterfly operation array and an FFT/IFFT Control Register. Parallel butterfly operation can be achieved by orderly execution, the complexity of hardware and operation is lowered, and the expansion of the hardware can be further facilitated.

Henrik Dal - One of the best experts on this subject based on the ideXlab platform.

  • Shift in Occupational Risk for Basal Cell Carcinoma from Outdoor to Indoor Workers: A Large Population-based Case-Control Register Study from Sweden.
    Acta dermato-venereologica, 2017
    Co-Authors: Bernt Lindelöf, Jan Lapins, Henrik Dal
    Abstract:

    Basal cell carcinoma (BCC) is the most common form of cancer worldwide. Exposure of the skin to ultraviolet (UV) radiation, from sunlight and other sources, is the most important risk factor. The aim of this large-scale case-Control study was to determine which occupations are associated with increased risk of BCC in Sweden. The case cohort comprised 74,247 patients with BCC and the Control cohort comprised 574,055 subjects linked to population-based Registers. Compared with the occupational category of farmers, foresters and gardeners we observed elevated risks of BCC for almost all occupational categories studied. Legal workers with odds ratio (OR) 2.69 (95% confidence interval (CI) 2.36-3.06), dentists OR 2.69 (95% CI 2.35-3.08) and physicians OR 2.47 (95% CI 2.24-2.74) had the highest risk for both sexes taken together. In conclusion, there appears to have been a change in the risk of BCC from outdoor to indoor occupations in Sweden, possibly related to exposure to UV radiation during leisure activities exceeding occupational sun exposure as the main cause of BCC in Sweden.