Determination of C54 nucleation site density in narrow stripes by sheet resistance measurements and μ-Raman spectroscopy

The kinetic of the C49–C54 phase transformation at 730°C in TiSi₂ narrow strips for width in the 0.5–1.3-μm range was investigated by resistance measurements and μ-Raman spectroscopy. With this last technique a growth rate of 0.15 μm/s and a nucleation density of about 0.035 sites/μm² were obtained. The fraction of the transformed material as measured by resistance follows the Johnson–Mehl–Avrami equation, with an exponent equal to 1 for all of the analysed linewidths. Nucleation site saturation occurs and the growth is one-dimensional along the length of the strip. The characteristic time increases as 1/W, W being the width of the strip, and, taking into account the growth rate obtained by μ-Raman spectroscopy, the nucleation density resulted 0.034 sites/μm² in excellent agreement with the μ-Raman results.     

基于89C55和82C54的光子计数仪的设计

介绍了82C54的基本功能和内部结构,控制寄存器的格式,模式0:计数结束发出中断信号的具体应用.本文给出了89C55单片机控制的硬件、软件设计实例.     

基于PIC16C54单片机的全自动豆浆机控制系统

介绍了以PIC16C54单片机为核心控制部件的全自动豆浆机的工作原理,给出了控制系统的具体硬件电路和软件设计方法.该豆浆机由粉碎黄豆的搅拌机、豆浆加热器和控制电路3大部分组成;性能稳定,使用方便,与市售的豆浆机相比,由于在豆浆沸腾后进行小功率加热熬煮,避免了继电器的过多动作和豆浆的溢出,并且产出的豆浆具有浓香风味;从黄豆的粉碎、过滤到豆浆的加热、煮熟全过程实现全自动,只需20 min即可制成1.4 L豆浆.     

Investigation of C49–C54 TiSi2 transformation kinetics

The C49C54 TiSi₂ polymorphic transformation has been investigated trying to elucidate the relative role played by nucleation and growth in silicide formation. Samples having an amorphous layer and C54 seeds have been made by heat treatment of a Ti/Si bi-layer structure and subsequent suitable Ar ion implantation. In situ resistance measurements performed during heat treatments in controlled and purified atmosphere at constant heating rates and ex situ X-ray diffraction, MeV ⁴He⁺ backscattering spectrometry and cross-section transmission electron microscopy have been used to characterize the samples. The results show that in a sample with C49 the C54 nucleation occurs at 800°C; when C54 seeds are present the growth is appreciable already at temperatures as low as 400–500°C. It has also been shown that nucleation and growth of the C49 phase is a process competitive to the growth of the C54 phase.     

Effect of heat transfer on the C49–C54 phase transformation in TiSi2 thin film

In this paper, the effect of heat transfer on the C49–C54 phase transformation in TiSi₂ thin film was investigated for the first time. Variation of the height of the chamber in the furnace during the annealing process was found to affect the sheet resistance (Rs) value of TiSi₂. By employing a moderate height of the annealing chamber, which makes it possible for the gas molecules inside to be more turbulent, the reduction of Rs can be achieved. From the standpoint of heat transfer theory, it has been proved in this paper that the enhancement of the thermal energy exchange between the wafer and the surrounding ambient contributes to the low resistivity C54 phase formation.     

TMS320C54XX系列DSP人机接口模块设计与实现

介绍了TMS320C54XX系列DSP人机接口模块的设计与实现方法.通过LCM1602与TMS320C54XX的I/O口软硬件接口设计,实现了显示功能;通过锁存器74HC573与TMS320C54XX的I/O口软硬件接口设计,实现了键盘功能.实际应用证明,该设计方法很好地实现了DSP对LCD点阵模块的驱动与显示,节省了I/O端口资源.     

PIC16C54在吸油烟机控制电路中的应用

本文从应用的观点出发简要介绍了PIC16C54在家电吸油烟机控制电路部分的使用情况。     

TMS320C54X DSP汇编程序的几种优化方法

通过研究TMS320C54XDSP汇编指令的特点及其流水线特性提出了四种优化其汇编程序的方法,它们是“部分循环展开法”、“并行指令使用技术”、“合理利用指针增减的思想”。“AR0作为循环次数法”。其中“部分循环展开法”是消除循环内部多余NOP语句的通用方法;“并行指令使用技术”提出了一种增大并行指令使用几率的通用方法。“合理利用指针增减的思想”是一种提高程序效率的编程思想。对于内层循环次数随着外层循环递增或者递减的二重循环,可用“AR0作为循环次数法”提高其效率。四种方法是从实际工作中抽取出来,具有通用性,其优化思想对其它具有流水线结构的MCU的汇编程序优化也具有一定指导作用。     

基于SST89C54/58的单片机仿真器的设计

介绍美国SST公司的51系列单片机SsT89C54／58的程序存储器的结构特点以及基于SST89C54／58的KEILC51单片机仿真器的设计。     

TMS320C54CST DSP的系统引导及调度算法的实现

底层引导和基于操作系统的调度与控制是DSP系统中用户应用程序和硬件的接口。基于TMS320C54CSTDSP芯片设计了数字电话系统的底层引导和调度控制程序。讨论了基于TMS320C54CST芯片的引导程序设计的关键技术,通过对DSP/BIOS实时内核的分析,给出了一种数字电话系统中基于DSP/BIOS实时操作系统的多任务调度策略。测试表明,本文的设计方案可行。     

TMS320C54x Simulator文件格式及其应用

详细介绍了TMS320C54x Simulator环境的文件格式及其文件加载步骤,以及如何将BMP或JPEG格式灰度图像转换为能够使TMS320C54x Simulator识别的格式文件.实例应用表明此方法能够将图像信息加载到TMS320C54x Simulator环境中,进行相应的图像处理.     

TMS320C54X DSKplus 与图形液晶显示模块 DMF50081 的接口设计

介绍了德州仪器公司为TMS320C54X系列DSP提供的入门开发套件DSKplus的性能特点 ,并自行扩展了128k×16bit的程序和数据内存 ,给出了用GAL20V8设计的DSKplus和液晶显示控制器SED1330的接口电路 ,以及通过该电路驱动点阵液晶模块DMF50081来实现字符和图形显示的软件方法。     

SST89C54与CF卡的接口设计与实现

介绍一种利用SST89C54读写CF卡的设计方法.所给出的接口电路避免了目前通过单片机读写CF卡必须依赖外部存储器和地址锁存器的弊端,实现了在True IDE模式下SST89C54对CF卡标准文件的读写.     

TMS320C54xx与TLV320AIC24型编解码器的接口设计

DSP由于其强大的数字信号处理能力而被广泛应用，而DSP与其他器件的接口方法是设计基于DSP器件的各种系统应重点考虑的问题。本文介绍一种TLV320AIC24型编码解码器与DSP的接口设计方法。给出TMS320C54xx与TLV320AIC24的硬件接口电路和部分软件程序。     

TMS320C54x在VSR数据采集与处理系统中的应用

振动时效(VSR)技术因其低耗能、省时、效果明显等特点,在国内外的研究进展与应用领域逐渐扩大。振动时效的核心装置是数据采集处理模块,只有精确数据获取、分析与计算才能保证系统的精度和可靠性。基于TMS320C54x与AD1674设计了数据采集与处理系统,分析了采集数据在时域及频域的特性。连续时间信号的时域分析借助于冲激响应和叠加原理求系统的零状态响应;而频域分析基于快速傅里叶变换,系统由TMS320C54x芯片完成数字滤波与快速傅里叶变换等数据处理工作,具有高速、高性能等优点。     

基于ROK101007型蓝牙模块和TMS320C54x型DSP的家用医疗保健智能机器人设计

未来社会将会越来越重视医疗保健服务,提出一种新型智能机器人,就其在数字化家庭医疗保健方面的应用进行模型设计,并将蓝牙技术应用在智能机器人与医疗仪器和控制PC的通信中.     

Small area versus narrow line width effects on the C49 to C54transformation of TiSi2

Polycrystalline silicon (poly) structures of equal area and varying line width were subjected to a standard self-aligned TiS₂ process. The poly lines had widths of 0.4, 0.5, 1.0, and 2.0 μm and the total contiguous silicided area ranged from 7 to over 2500 μm₂. On all large area structures (silicided area >100 μm₂) our findings were consistent with the well-known narrow line width effect; i.e., the kinetics of transformation were adversely affected as the line width decreased, but with a sufficiently high thermal budget complete transformation to the C54 phase was possible. However, on structures with silicided area less than 100 μm ₂, a small area effect was observed in addition to the narrow line width effect. A percentage of small area lines remained entirely in the C49 phase (because of an apparent absence of C₅₄ nucleation sites) regardless of the thermal budget. This percentage increased with decreasing silicided area but was independent of the line width. Only the small area lines that did transform to the C54 phase exhibited the narrow line width effect. Therefore, for the range of line widths studied, the narrow line width mechanism and the small area mechanism were distinct     

Oscillatory kinetics of anodic oxidation of silicon – influence of the crystallographic orientation

This work describes the oscillatory kinetics of the anodic oxide growth on silicon with crystallographic orientations (1 1 1) and (1 0 0). Although the oscillations are observed for two orientations if the experimental variables are properly chosen, their shape, amplitude and period are essentially different. It is shown that the oscillations are caused by a continuous growth of thin oxide layers at the sample surface and their peeling off.An analysis of the morphology of the samples and their kinetics of growth shows that the oscillatory anodization kinetics is a self-organizing phenomenon emerging as a result of collective interactions in the electrolyte/Si system. These interactions are influenced by the crystallography of silicon. The case of (1 1 1) Si shows the presence of the correlation links in a sequence of individual oscillations nearly two times longer than in the case of (1 0 0) Si . These differences are attributed to different mechanisms of the pore formation in (1 1 1) and (1 0 0) silicon wafers.     

Rapid Near‐Infrared Light Responsive Shape Memory Polymer Hybrids and Novel Chiral Actuators Based on Photothermal W18O49 Nanowires

Photoresponsive actuators are built by introducing oligo(ethylene glycol) (OEG)‐modified W₁₈O₄₉ nanowires into cross‐linked polyethylene glycol diacrylate (cPEGDA) polymer matrices. Due to the good compatibility, OEG‐W₁₈O₄₉ NWs disperse well and increase the crystallinity of cPEGDA matrices even in high loading concentrations (4.0 wt%). The cPEGDA/W₁₈O₄₉ nanocomposites show efficient photothermal transition and rapid shape memory behaviors. They can raise the local temperature to 160 °C in only 8.5 s and recover the initial shape within 10 s. Making use of the broad and strong absorption property of W₁₈O₄₉, the cPEGDA/W₁₈O₄₉ NW actuators respond to both ultraviolet and near‐infrared light and make contraction and bending motions. Furthermore, by utilizing oriented chain segments of the crystalline polymer and vector sum of shape recovery forces, the cPEGDA/W₁₈O₄₉ NW hybrid actuators exhibit stable helical deformation (right‐handed and left‐handed).     

机载适航标准DO-178B/C软件计划过程研究

介绍了DO-178B/C标准的发展历程,结合对DO-178B/C标准软件生命周期过程的研究,从活动、子过程转段及顺序、生命周期环境、其它因素、开发标准、计划满足DO-178B/C要求以及计划的开发与修正等7个方面对软件计划过程进行了研究,并对关注点进行了分析,最后展望了DO-178B/C标准的未来研究方向.