基于CPLD的8位总线接口设计

基于CPLD技术设计了双通道总线接口并给出谊接口的通道模型和控制方法。本接口采用存储嚣访问模式，克服了某些CPU外围通信接口少的缺点，易于实现双CPU间的总线对接，且无需考虑复杂的总线仲裁机制。谊接口适用于双主机间的数据传榆，具有使用方便、速率匹配、实时响应等优点。同时采用VHDL硬件描述语言，使设计易于模块化，也为基于CPLD的总线转换及其他接口电路的设计提供了新的思路。     

AHB总线仲裁器的设计

介绍了AHB总线仲裁信号,对其仲裁机制和仲裁过程进行了详细的说明.在MAX plusⅡ软件平台上,采用自顶向下的设计方法,将整个设计分为3个模块,底层模块使用甚高速集成电路硬件描述语言(VHDL)设计,然后包装入库,顶层文件采用原理图输入法,实现AHB总线仲裁器的设计,并给出仿真结果.     

一种FIFO队列的总线仲裁器的设计

本文基于总线仲裁机制和常用的仲裁协议提出了一种混合优先级仲裁算法,和队列相结合的总线仲裁的解决方法,这种设计方法即保证了高优先级主设备的优先性,又保证了其他主设备的公平性,同时也避免了“死锁”和“饥饿”现象。本文详细介绍了此算法的设计过程和仿真结果。     

基于FIFO队列的PCI总线仲裁器的设计与FPGA实现

系统地论述了PCI总线的仲裁机制和常用仲裁协议,简要地分析了常用仲裁协议的优缺点,并在此基础上介绍了一种基于循环优先级仲裁协议和FIFO队列相结合的PCI总线仲裁器的实现方法,旨在解决目前PCI总线仲裁协议中由于优先级循环出现的特权插队问题,并详细说明了基于循环优先级仲裁协议与FIFO队列相结合的总线仲裁器的设计和FPGA硬件实现。     

用CPLD实现PCI总线仲裁器

介绍了PCI总线仲裁的工作机制,并且根据旋转优先算法用VHDL语言进行CPLD设计,通过作者实际研发项目WAS(无线应用服务器)单板的应用,论证了其可行性和稳定性.     

嵌入式微处理器接口总线控制器的CPLD设计

介绍了用复杂可编制逻辑器件（CPLD）来实现嵌入式微处理器（MCU）和DSP处理器之间端口数据总线逻辑控制电路的设计,给出了接口数据总线逻辑的设计电路和部分仿真结果,证明本文采用的系统结构具有设计灵活、设计开发周期短的优点。     

基于博弈论的片上总线仲裁机制研究

随着半导体工艺技术的发展,芯片内部集成的功能模块越来越多.各功能模块通过总线方式连接,因而片上总线仲裁架构成为制约芯片性能提高的瓶颈.通过改善片上总线仲裁器设计,能有效缓解由于各功能模块争用总线资源而引起的芯片性能下降.本文提出一种基于博弈论的片上总线仲裁机制,利用求解多人博弈问题的方法解决总线争用问题,并以片上系统的性能指标为约束条件,得到解决总线争用问题的一般模型.最后,通过仿真及实际硬件平台对算法进行测试,结果表明应用本算法的指令处理速度比应用固定优先级算法快236%,比应用轮换算法快53%.     

LPC214x系列微控制器中的I^2C总线接口实现

详细介绍了LPC214x系列微控制器中I^2C总线接口的模块组成及其功能。给出了LPC214x系列器件片内I^2C总线接口的工作流程以及操作过程。同时给出了其接口仲裁过程及串行接口时钟同步时序。     

基于STM32的航空通信总线切换器设计

ARINC429是目前最常用的一种航空通信总线,它具有简单有效,性能可靠等特性。利用ARINC429总线,飞控系统同各机载设备进行通信,但不同设备上并非都采用ARINC429接口,如卫星接收机采用RS 422总线,且飞控系统ARINC429接口有限。为解决这一问题,提出了基于STM32的航空通信总线切换器设计,方案选取了意法半导体的STM32微控制器,具有高度一体化,低功耗,处理速度快,方便调试与后续开发等优点。     

混合优先级PCI设备的总线仲裁算法及其Stateflow建模

提出了一种PCI总线的混合优先级仲裁算法,并将该算法应用于某视频监控主机的PCI总线系统,建立了其基于Stateflow的模型。该算法是固定和循环优先策略的有机结合,因而它既继承了前者的设备优先级属性的存在差异化的事实也体现了后者的设备优先级属性获取上公平性。仿真试验表明了该PCI总线策略的可行性和模型的正确性。     

MPEG4视频编/解码方案

本文分析了基于BlackfinADSP-21535实现MPEG4视频编/解码的实用性与可行性。     

On modeling MPEG video traffics

This paper traces the development/evolution of three of our previously proposed MPEG coded video traffic models, that can capture the statistical properties of MPEG video data. The basic ideas behind these models are to decompose an MPEG compressed video sequence into several parts according to motion/scene complexity or data structure. Each part is described by a self-similar process. These different self-similar processes are then combined to form the respective models. In addition, Beta distribution is used to characterize the marginal cumulative distribution (CDF) of the self-similar processes. Comparison among the three models shows that the latest model (called the simple IPB composite model) is the most practical one in terms of accuracy and complexity. Simulations based on many real MPEG compressed movie sequences, including StarWars, have demonstrated that the simple model can capture the autocorrelation function (ACF) and the marginal CDF very closely.     

Study on adaptive job assignment for multiprocessor implementationof MPEG2 video encoding

The high demand on computation performance by multimedia information processing such as digital video compression and decompression has made multiprocessor computation more and more popular. In this paper, we present our study on adaptive job assignment for multiprocessor implementation of a Motion Picture Expert Group 2 (MPEG2) video encoding algorithm. Data partitioning technique is used for job assignment to the processors in the multiprocessor environment to exploit the data structure adopted by the MPEG standard that divides a frame of a picture into macro blocks (MBs) which are processed independently during encoding. An adaptive data partitioning scheme is developed to cope with the inherent nonuniform spatial distribution of motion activities, such that the computation load distribution over processors is as uniform as possible, which helps improve the speedup of the whole multiprocessor system. Simulations with several video sequences have shown that, in comparison to its nonadaptive counterpart, the adaptive scheme can effectively improve the speedup of the multiprocessor system. In addition, the speedup scales well with the increase of the number of processors used in the computation     

Quality-optimised MPEG2 video data rate control using fuzzy logictechniques

Fuzzy logic control has been employed to improve the rate control mechanism for a MPEG2 video encoder. The data rate of compressed video is controlled by video encoders for either variable bit rate (VBR) or constant bit rate (CBR) applications. In VBR video transmission, it is considered to be more efficient to regulate the video rate by the video coder than by network management in order to avoid network congestion and maintain stable video quality. This rationale can also be applied to CBR transmission. Two fuzzy-logic-based rate control techniques are proposed which maintain the buffer occupancy within a specified range. In the proposed technique for VBR applications, a video quality measure is taken as the crucial control parameter. In CBR rate control, the video data rate or the buffer occupancy is also considered as a fuzzy logic variable. Proposed techniques are designed to control either data rate or video quality, depending on the mode of transmission, i.e. CBR or VBR for the MPEG2 encoder. The performance is compared to a typical VBR MPEG video coder with fixed quantiser step sizes for VBR and also to the CBR video coder with MPEG2 TM5 at typical channel rates. Simulation results are presented with peak signal-to-noise ratio, data rate variation and buffer occupancy as the performance measures     

MPEG2-TS VBR码流质量监测技术

MPEG2-TS VBR编码技术日益广泛使用,但传统的基于MDI-DF的算法不太适合检测VBR码流的传输质量问题.提出了MPEG2-TS VBR码流质量评估算法,通过监测MPEG2-TS码流的PCR字段,计算在单位时间内接收到的VBR视频流的可播放时长与单位时间的绝对偏差量,根据绝对偏差量评价VBR视频流传输质量.实验结果证明该算法具有可行性和时效性.     

Super-resolution mosaicing from MPEG compressed video

In this paper we address the problem of mosaic construction from MPEG 1/2 compressed video for the purpose of video browsing. State-of-the-art mosaicing methods work on raw video, but most video content is available in compressed form such as MPEG 1/2. Applying these methods to compressed video requires full decoding which is very costly. The resulting mosaic is in general too large to display on the screen and is thus inappropriate for the purpose of video browsing. Therefore, we directly extract very low-resolution frames from MPEG 1/2 compressed video for the mosaic construction and then apply a super-resolution (SR) method based on iterative backprojections in order to increase the mosaic resolution and its visual quality. Global motion to be used in the SR method for aligning and warping the frames is estimated from motion information contained in the compressed stream. We also use the estimated global motion in the blur estimation and in the choice of the degradation model used for the restoration in the SR algorithm. The method for the SR mosaic construction from MPEG 1/2 compressed video that we present in this paper is less costly than mosaic construction from full decoded video. Furthermore, the resulting mosaic size is more appropriate for the purpose of video browsing.     

Supporting MPEG video transport on DOCSIS-compliant cable networks

A novel quality of service (QoS) scheduling mechanism suitable for transporting variable bit rate video in the upstream direction over a DOCSIS (data over cable system interface specification)-compliant cable network is presented. It is shown, via simulation using real life video traces, that the proposed scheduling service provides significant improvements as compared to the existing DOCSIS QoS scheduling services, with regard to bandwidth utilization and latency distribution. The proposed scheduling service is also applicable to transport integrated services over the Internet and can be utilized by other emerging multimedia applications, where data are bursty in nature and variable in bit rate     

基于视频内容的MPEG视频VBR业务流量模型

视频业务流量模型是网络性能仿真的一个重要前置环节,但由于视频内容的千差万别,使得很难建立统一的视频业务流量模型。本文根据MPEG视频图像内容的纹理及运动复杂度,通过3×3 Kohonen自组织神经网络对视频序列进行划分,将其分割为一段段近似平稳的“视频片段”。然后,用半马尔可夫随机过程描述“视频片段”间的转移概率及其持续时间分布规律,用AR模型描述“视频片段”内部过程,从而建立了一种通用MPEG视频业务流量模型。     

基于PCI总线的MPEG - 2码流播放卡驱动程序开发

结合DriverStudio软件包,详细阐述了MPEG-2码流播放卡驱动程序的开发,重点介绍了对硬件资源的访问、DMA数据传输过程和中断处理部分,并简要介绍了驱动程序安装文件的修改.