嵌入式操作系统教学方法研究

提升电子信息工程专业学生分析问题和解决问题的能力,是建设课程思政的重要任务。嵌入式操作系统专业课程内核要素众多且相互耦合,导致学生较难理解这门专业课程的知识点。针对此,本文从内核要素、运行时序和案例分析的角度,研究嵌入式操作系统教学方法,通过教学案例和学生实验成绩验证了所提教学方法的教学效果。该教学方法有助于提升该门课程的教学效果。     

设计工具与服务

基于钻石系列标准处理器内核的SOC设计流程Magma设计自动化公司和Tensilica公司联合宣布基于Blast Create和Blast Fusion集成电路应用系统(implementation system)的从RTL到GDSⅡ的设计流程,该流程支持Tensilica钻石系列标准处理器内核。Magma的方法基于Blast Create从RTL到已布局的门单元和Blast Fu- sion物理设计的解决方案,包括了流     

可重复使用性设计得到EDA厂商支持

为设计具有几百万个逻辑门的芯片,必须包含“内核”,即预先定义和预先验证的逻辑块。Mentor Graphics公司向着成为软核——带有知识产权(Inventra Intellectual     

可测试设计法提高集成电路成品率

现今,集成电路芯片设计中,门计数和复杂程度日益增加,IBM公司的专用集成电路(ASIC)的平均设计量为1.3百万门。1998年出现首次突破5百万门(随机逻辑)的设计。这种较大型设计中结构的测试更为困难。RAM、ROM、内核、数据流水线、三态总线和多时种域的高质量能力提出更高要求的测试,而设计周期又不能延长。     

半导体和IC

系统可编程门阵列器件Ａｃｔｅｌ公司宣称研制成业界第一个系统可编程门阵列（ＳＰＧＡ）──ＥＳ（嵌入式ＳＰＧＡ）系列。该系列的第一个成员Ａ６５ＥＳ１００，是用该公司新的可重编程ＥＳ结构制作的１０万门器件。ＳＰＧＡ是可编程的单片系统，提供业界领先的逻辑集成，可预测的反复使用的软积本块或专用内核，而经济效益则接近传统的掩膜可编程门阵列。ＥＳ产品系列共有八种器件：六种可重编程ＳＰＧＡ，集成密度从５万门到４０万门；两种包括嵌入式内核的器件。嵌入式ＳＰＧＡ器件把掩膜可编程ＡＳＩＣ块纳入可编程ＥＳ结构，使得设计…     

Windows内核态钩子在软件安全技术中的应用

阐述了Windows内核的特点、通过驱动程序进入内核态的方法,剖析了Windows内核中几种数据结构,在此基础上讨论了在内核不同位置安装钩子从而实现安全保护的技术,指出了内核态钩子在软件安全技术中的必要性和发展趋势。     

Win32平台下内核溢出的原理与攻击方法

针对系统内核的溢出是当今研究溢出漏洞攻击的发展趋势,而内核溢出主要是由处在系统内核态的驱动程序中的漏洞所产生,文章通过分析Win32平台下的一个内核驱动程序漏洞实例,详细阐述了内核溢出漏洞的产生原理,并引出了相应的攻击方法。     

μC/OS-Ⅲ实时内核在F28M35x器件上的移植

在微控制器中使用实时内核可以简化嵌入式应用开发。简单介绍了μC/OS-Ⅲ实时内核和Cortex-M3内核的相关内容,将μC/OS-Ⅲ实时内核移植到F28M35x多内核片上系统微控制器中,并阐述了μC/OS-Ⅲ实时内核中任务的创建和调度原理,最终在目标板上运行并进行多任务切换。     

基于ARM的嵌入式linux内核的裁剪与移植

针对交叉编译环境的建立,修改Makefile,设置flash分区,配置内核,编译内核以及下栽内核映像到开发板等设计,给出了以s3c2410为核心的嵌入式iLnux内核的裁剪与移植过程。     

移动通信系统中的f9算法的研究

移动通信中的f9算法是信令消息的完整性验证算法,它通过内核算法计算出信息的消息认证码,内核算法的安全性决定了f9算法的安全性。针对这个特性,提出了以IDEA为内核算法的f9算法,并与原内核为KASUMI的f9算法在加密速度上进行了比较。实验结果表明内核为IDEA的f9算法在加密速度上有了明显的提高。     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

中国建立EB级存储实验室,致力云计算应用(英文)

正With the support of 863 programs,Sugon Information Industry Co.,Ltd.,set up a dawning EB-class storage laboratory to address massive data storage requirements and largescale cloud computing demonstration applications.The Dawning EB-class cloud storage system adopts advanced fault-tolerant architecture,efficient data fault-tolerant algorithms with user authentication and data encryption policies to deal with the"lost""wrong"and"stolen"problems of data for ensuring the reliability and safety of the EB-class storage system in the public network application environments.The Dawning EB-class Storage Laboratory taking advan-