基于DSP验证平台的MP3解码算法研究与实现

本文针对基于16位定点DSP核的MP3解码算法研究及实现,提出了针对DSP芯片特点的软硬件优化设计方法,包括高级语言算法的结构优化和汇编语言的软硬件优化.在DSP验证平台上进行128Kbps,44.1KHz的立体声MP3解码,优化后运算量为46.6MIPS,程序空间为20.4Kbyte,优化率分别达到65.6%和49.6%.实验结果表明音频算法和DSP结构软硬件协同设计的重要性.     

基于DSP验证平台的MP3解码算法研究与实现

本文针对基于16位定点DSP核的MP3解码算法研究及实现,提出了针对DSP芯片特点的软硬件优化设计方法,包括高级语言算法的结构优化和汇编语言的软硬件优化.在DSP验证平台上进行128Kbps,44.1KHz的立体声MP3解码,优化后运算量为46.6MIPS,程序空间为20.4Kbyte,优化率分别达到65.6%和49.6%.实验结果表明音频算法和DSP结构软硬件协同设计的重要性.     

基于PowerPC405的MP3实时解码系统设计与实现

文章介绍了一种在FPGA上用PowerPC405实现MP3实时解码SoC系统的方法。通过使用IP核搭建SoC硬件结构,并进行定点MP3解码软件算法移植,完成软硬件协同设计和验证,实现MP3音乐实时、高品质的解码播放。     

MP3解码器的SOPC实现

简单的介绍了MP3的解码原理,并应用SOPC技术构建快速合适的硬件系统,以Altera公司的NiosII软核处理器作为控制及解码单元来完成MP3解码器的设计。对MP3解码器中主要算法模块做了优化和改进,用Verilog语言来实现MP3解码器的RTL设计,并在DE2-70开发板上得到了实时验证,达到了较好的优化效果。     

基于ARM946E处理器的MP3解码优化设计

对于消费类电子产品来说,在不增加硬件成本的情况下实现MP3软解码具有较大的现实意义.为了额外增加产品的MP3功能,在分析MPEG I Audio Layer3解码算法的基础上,提出基于ARM946E处理器的MP3解码优化设计方法,其主要包括解码算法和代码实现2方面,并根据ARM946E处理器支持DSP扩展指令的特点进行代码优化,通过在硬件平台上的运行验证了软件优化的正确性,并取得了比较好的实时解码效果.     

基于多任务嵌入式应用的MP3实时解码系统设计

给出一种基于多任务嵌入式应用的MP3实时解码系统设计方法及实现过程.该系统针对以ARM926EJ-S处理器为核心的SoC硬件平台,通过对MP3解码过程中的关键耗时模块进行算法优化,提高解码效率,达到实时播放的要求.实验结果证明,该系统可在处理器主频仅为36 MH2的条件下流畅播放MP3音乐(码率为192 kb/s).该设计特点为根据子带合成滤波中乘法运算的数据特征,巧妙地对操作数进行预移位操作,从而在保证一定数据精度的基础上缩短乘法运算的指令周期,实现解码效率的大幅度提升.提出一种利于高效任务调度的实时播放方案,对于高实时性、低功耗多任务嵌入式系统设计具有很好的参考意义.     

基于DSP的MP3实时解码系统的设计与实现

介绍了一种基于定点DSP的MP3解码系统的设计与实现。系统以高性能的定点DSPTMS320vc5416为核心处理器,通过对DSP的软件编程实现对MP3数据实时解码。     

MP3编码量化模块的改进

MP3是应用最广泛的一种音频格式,MP3解码芯片已发展成熟,却很少有实时编码器产品。这是因为MP3编码算法的运算量远大于解码算法,而量化模块在编码算法中占很大的比重(38．2％),为实现便携式设备的MP3实时编码,有必要对量化模块进行改进来降低运算复杂度。在分析了现有的一些改进方法后,提出了在外循环中限制量化频带以滤去高频信号,计算比例因子初值以减少循环次数;内层循环中计算量化因子初值后自适应调整步长的方法。在获得良好音频质量的同时将量化模块运算量减少到标准算法的6％,使得整个编码算法的运算量降低到标准算法的64％,配合简化声学心理模型和分析滤波器组快速算法,可在单片DSP或ARM上实现MP3实时编码。     

用定点DSP实现MPEG-2 AAC实时解码器

MPEG－2AAC（ISO／IEC13818－7）是一种高效多声道Hi-Fi音频编码标准,在每声道64kbps时重建音质优于MP3和AC－3。文中在介绍其解码流程的基础上,讨论了对其关键模块的优化措施,研究了基于定点DSP的AAS实时解码器的实现方法。实现了TMS320C549EVM板上对AAC（LC）码流的实时解码播放。     

基于软硬件协同设计的Huffman解码模块

随着多媒体技术的迅猛发展,数字音频技术也快速发展起来。MP3是一种有损音频压缩编码,其压缩程度很高,目前在很多领域已经开始广泛应用,具有良好的市场前景。主要基于软硬件协同设计的方法,实现MP3的Huff-man解码模块。提出的解决方案不仅可以实现对MP3的Huffman模块的高效解码,同样也可以应用于WMA、AAC等其他音频格式的Huffman模块,在保证高效的同时,兼顾了模块的通用性。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

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.     

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.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

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.