摩托罗拉8位HC08微控制器系列

摩托罗拉微控制器(MCU)具有编程语言简单、外围设备齐全、存储器模型用户友好、选择广及供应多、性能价格比高等优点,被设计者评为最容易使用的产品之一。在全球顶级的原始设备制造厂商(OEM)的无数嵌入式系统和用户最终产品中都可找到摩托罗拉的MCU,包括键盘、传呼机、电子游戏机、洗衣机、安全系统及汽车等。     

适合汽车引擎和传动系统控制的微控制器

适用于汽车引擎和传动系统控制的SuperH系列微控制器SH72544R具有高达200MHz的高速运算能力及高速、大容量2．5MB片上闪存功能。     

极品影像日立W21H

Style-up炫尚外壳加上小巧的机身和QVGA屏幕,A1402S让人一见倾心。 索爱A1402S是目前最小的配备QVGA液晶屏幕的移动电话,采用了流行的双彩屏折叠设计,机身尺寸为99×47×22(毫米),重量为104克。从参数上看似乎并不十分理想,“世界最小”从何而来呢?原来A14025拥有一个2.3英寸的超大TFT屏幕,不仅支持26万色显示,屏幕分辨率更达到了320×240像素。因此和其他拥有QVGA液晶屏幕的手机相比,A1402S与普通折叠     

兼容DVD-RAM和DVD-R的日立DZ-MV系列摄录机

如今，DVD播放机已取代VCD成为家庭视听娱乐的主要讯源，有的家庭还拥有能够播放DVD光盘的个人电脑。由于DVD采用的MPEG-2压缩格式具有很高的效率，记录的图像质量也远远胜过传统的VHS磁带摄录机，人们理所当然地要求把家用摄录机拍摄的图像记录在DVD光盘上。这样，只需把拍摄记录的DVD光盘放入家庭现有的DVD播放机即可欣赏拍摄的高品质画面。然而，事情并非这样简单。     

MC68300系列微控制器的特点和应用

ＭＣ６８３００系列微控制器的特点 Ｍｏｔｏｒｏｌａ公司的ＭＣ６８３００系列微控制器采用模块化设计，可以根据用户的要求，选择不同的模块，以适应不同的应用场合。现在广泛使用的己有十余种产品，其组成如图１所示。 它们具有以下共同的特点／模块： （１）中央处理单元（ＣＰＵ）采用在ＭＣ６８０２０基础上形成的３２位ＣＰＵ，称作ＣＰＵ３２。它与ＭＣ６８０２０的指令系统基本相同，并且还增加了多条适合于微控制器应用的指令，这样，在开发过程中就可以充分利用已有的成果。最高工作频率己达２５Ｍｚ。 （２）由于采用了全静态设…     

日益增长的8位微控制器及其新的应用

电子工业发展最快的活动之一是在许多廉价的日用产品中增加嵌入控制.过去几年里,公众 已经听说Intel公司、Motorola公司等为其台式PC机提供了“大脑”.公众对于半导体的作用的认识正在日益深化.他们通常认识不到的是在他们日常使用的产品上增加程度不等的智能.低档和中档微控制器是使许多小而便宜的电子装置增加智能的解决方案.而且花钱不多.新式洗衣机不仅省电,而且还节水.大多数消费者尚未认识到,他们的新式微波炉、电冰箱或电烤箱其实是一台具     

为微控制器应用开发PLD产品

概述 一些微控制器的用户也使用可编程逻辑器件(PLD),增加现有MCU不具备的硬件功能,或为整个系统性能至关重要的功能提供硬件加速。随着超大容量的PLD象APEX 20KE系列的出现,它可以把整个16和32位MCU或微处理器以及系统设计者所要求的更多功能整合到单个可编程器件中。这种方式实现的更大集成度可以满足许多     

飞思卡尔公布新的微控制器产品路线图

飞思卡尔半导体(Freescale)日前公布了其微控制器产品路线图,新系列8位和32位器件具备针脚兼容的特性,并将共享外围设备接口和一套通用开发工具。飞思卡尔计划扩展低端和高端8位系列产品。该公司将推出更低成本的改进产品,适合于刚接触微控制器的新设计者;另外还将提供增强的外     

New design of full band differentiators based on Taylor series

The classical central difference approximations of the derivative of a function based on Taylor series are the same as type III maximally linear digital differentiators for low frequencies. A new finite difference formula is derived which can be implemented as a full band type IV maximally linear differentiator. The differentiator is compared with type III maximally linear and type IV equiripple minimax differentiators. A modification is proposed in the design to minimise the region of inaccuracy near the Nyquist frequency edge     

New method for the efficient summation of double infinite series arising from the spectral domain analysis of frequency selective surfaces

When the method of moments (MoM) in the spectral domain is applied to the analysis of frequency selective surfaces, the entries of the MoM matrix are slowly convergent double infinite series. In this paper, a two-step acceleration technique is developed which makes it possible the fast and accurate computation of these double series in the particular case where subsectional rooftops are used as basis functions. The technique is based on a combination of the use of Kummer's transformation, the use of Poisson's transformation, and the determination of judicious Chebyshev polynomial interpolations of some of the spectral discrete functions involved in the infinite series. The results obtained show that when all the double series of the MoM matrix are to be computed with an accuracy of three significant figures, the new acceleration technique turns out to be about one thousand times faster than brute-force computation, and a few times faster than the acceleration technique based on fast Fourier transform.     

Derivation of Fourier transform of discrete series from z-transform

The relationship between z-transform and Fourier transform of a discrete series is presented. The Fourier transform of a discrete series whose z-transform has poles on the unit circle can be derived using these results.<>     

Inband scattering from arrays with series feed networks

Approximate equations are presented for the radar cross section (RCS) of a phased array antenna with a series feed beamforming network. The incident radar wave is assumed to be at the same frequency as the antenna operating frequency. In deriving the RCS formulas, multiple reflections are neglected, and like devices in the feed are assumed to have identical transmission and reflection coefficients. The approximate results are shown to be in excellent agreement with results obtained using a scattering matrix approach. The behavior of the RCS as a function of several feed design parameters is also investigated     

New series half-bridge converters with the balance input split capacitor voltages

This article presents a new dc/dc converter to perform the main functions of zero voltage switching (ZWS), low converter size, high switching frequency and low-voltage stress. Metal–oxide–semiconductor field-effect transistors (MOSFETs) with high switching frequency are used to reduce the converter size and increase circuit efficiency. To overcome low-voltage stress and high turn-on resistance of MOSFETs, the series half-bridge topology is adopted in the proposed converter. Hence, the low-voltage stress MOSFETs can be used for medium-input voltage applications. The asymmetric pulse-width modulation is used to generate the gating signals and achieve the ZWS. On the secondary side, the parallel connection of two diode rectifiers is adopted to reduce the current rating of passive components. On the primary side, the series connection of two transformers is used to balance two output inductor currents. Two flying capacitors are used to automatically balance the input split capacitor voltages. Finally, experiments with 1000 W rated power are performed to verify the theoretical analysis and the effectiveness of proposed converter.     

基于泰勒级数展开的蜂窝TDOA定位新算法

在蜂窝移动通信系统中，TDOA（到达时间差）是目前最有发展潜力的无线定位技术。其中的泰勒级数展开算法因为具有精度高和顽健性强等特点在求解非线性定位方程组中得到了广泛的应用，但它对初始值有很强的依赖性。在此基础上，提出一种混合优化算法（HOA，hybrid optimizing algorithm）将泰勒级数展开算法和最速下降法有机结合，扬长避短，既继承了泰勒级数展开算法的精确性和顽健性，又具备最速下降法迭代前期收敛速率快，计算量小的优点。仿真结果表明HOA算法能显著提高传统的泰勒级数展开算法的定位精度和定位效率。     

用于低维混沌时间序列预测的一种非线性自适应预测滤波器

在二阶Volterra滤波器基础上,提出了一种用于低维混沌时间自适应预测的非线性自适应预测器。基于最小均方误差准则导出了一种NLMS类型的自适应算法来实时调整这种非线性滤波预测器的系数,仿真实验结果表明：这种线性化的非线性自适应滤波预测器能够有效地预测低维混时间序列,且它的模块化特征更易于VLSI电路实现,具有广泛的工程应用价值。     

New technique for determination of static emitter and collector series resistances of bipolar transistors

Starting with detailed investigations of the IC/VCE characteristics in the vicinity of the origin it is shown how the static emitter and collector series resistances of bipolar transistors can simply be determined using a curve tracer. Experimental results demonstrate the efficiency of this technique.     

Multiple Fourier series procedures for extraction of nonlinearregressions from noisy data

Three nonparametric procedures for the extraction of nonlinear regressions from noisy data are proposed. The procedures are based on the Dirichlet, Fejer, and de la Vallee Poussin multiple kernels. Convergence properties are investigated. In particular, it is shown that the algorithms are convergent in the mean-integrated-square-error sense. The appropriate theorem establishes a relation between the order of kernels and the number of observations. Special attention is focused on the two-dimensional case. It is proved that the procedures attain the optimal rate of convergence, which cannot be exceeded by any other nonparametric algorithm     

Vibration parameter extraction from endoscopic image series of the vocal folds

An approach is given to extract parameters affecting phonation based upon digital high-speed recordings of vocal fold vibrations and a biomechanical model. The main parameters which affect oscillation are vibrating masses, vocal fold tension, and subglottal air pressure. By combining digital high-speed observations with the two-mass-model by Ishizaka and Flanagan (1972) as modified by Steinecke and Herzel (1995), an inversion procedure has been developed which allows the identification and quantization of laryngeal asymmetries. The problem is regarded as an optimization procedure with a nonconvex objective function. For this kind of problem, the choice of appropriate initial values is important. This optimization procedure is based on spectral features of vocal fold movements. The applicability of the inversion procedure is first demonstrated in simulated vocal fold curves. Then, inversion results are presented for a healthy voice and a hoarse voice as a case of functional dysphonia caused by laryngeal asymmetry.