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《微型机与应用》2016,(13)
设计了一套新型便携式脑功能近红外信号采集传输系统。根据功能近红外光谱技术(functional Near-infrared Spectroscopy,f NIRS)检测脑血氧浓度原理,使用双波长的LED和光电传感器作为探头,可以对脑功能近红外信号进行实时采集传输,并对数据进行显示保存。该系统下位机采用STM32F407单片机和TI公司的ADS1299模拟前端集成构成,体积小,功耗低,精度高,通过USB HID协议与上位机进行数据传输,方便快速,避免了驱动程序的开发。上位机程序利用VS2010进行开发,调用与USB HID设备相关的Windows API函数,实现上位机与下位机之间的通信。 相似文献
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系统调用是操作系统提供的一系列函数,它在嵌入式系统开发中起着重要的作用,驱动程序的设计和系统调用密切相关.因此,简单论述了嵌入式系统开发中驱动程序设计的重要性,说明了驱动程序的基本结构和实现原理.最后通过系统调用函数Write详述了系统调用函数实现的过程与机制,并总结了嵌入式Linux下系统调用的具体步骤. 相似文献
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任志敏 《自动化技术与应用》2013,32(1):20-24
本文介绍了基于USB2.0接口的68013A的图像采集板设计方案,包括硬件设计,下位机程序设计,上位机程序设计,USB驱动程序改写.在此基础上,实现了PC端实时显示感光芯片OV6620输出的数字信号图像. 相似文献
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针对基于PCIe总线通用RS422/485串行接口板卡无法完全国产化问题,设计了一种基于复旦微JFM7K325T高性能FPGA,通过逻辑实现PCIe总线控制、UART串口控制的多通道隔离串口板卡。模块包括FPGA电路、电源电路、隔离RS422/RS485接口电路、FPGA逻辑,上位机通过PCIe总线实现多路串行接口的数据收发。实际测试结果表明,多通道串行接口可实现常用波特率连续读写,数据稳定,各通道电地单独隔离。该设备应用稳定可靠。 相似文献
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介绍了基于MX组件的三菱PLC监控系统设计过程及应用,以MX组件作为底层驱动接口,采用C#程序调用ACT控件中的函数,实现了上位机PC与不同型号三菱PLC之间的通信,奠定了监控系统设计的基础。并以三菱FX2NPLC为例,采用RS485为通信方式,完成了上位机PC对该PLC软元件状态与数据的实时采集和控制,在此基础上开发了某测试系统人机界面,经现场实际运行表明,效果良好。 相似文献
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研究并介绍在WINDOWS95/98环境下,VtoolsD如何支持直接内存读写(DMA)操作以及如何调用相关的C++类与成员函数实现该操作,给出了虚拟设备驱动程序(VXD)实现DMA操作的编程实例。 相似文献
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嵌入式Linux下的MMC/SD卡的原理及实现 总被引:5,自引:0,他引:5
随着计算机硬件的发展及数据量的增加 ,对存储设备的要求也越来越高。闪存卡以其特性成为移动设备上的首选存储媒介。而且由于MMC卡与SD卡的硬件接口是兼容的。因此 ,该文在Motorola的DragonballMX1平台的基础上 ,描述了MMC/SD卡的硬件接口 ,给出了硬件接口部分的原理图。并介绍了在此嵌入式系统中使用它的一些相关操作及其顺序。最后介绍了Linux下设备的分类 ,给出了编写块设备驱动的相关数据结构及函数 ,详细说明了在Linux环境下编写相应的驱动程序的方法及注意事项 相似文献
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Multiplication of polynomials of large degrees is the predominant operation in lattice-based cryptosystems in terms of execution time. This motivates the study of its fast and efficient implementations in hardware. Also, applications such as those using homomorphic encryption need to operate with polynomials of different parameter sets. This calls for design of configurable hardware architectures that can support multiplication of polynomials of various degrees and coefficient sizes.In this work, we present the design and an FPGA implementation of a run-time configurable and highly parallelized NTT-based polynomial multiplication architecture, which proves to be effective as an accelerator for lattice-based cryptosystems. The proposed polynomial multiplier can also be used to perform Number Theoretic Transform (NTT) and Inverse NTT (INTT) operations. It supports 6 different parameter sets, which are used in lattice-based homomorphic encryption and/or post-quantum cryptosystems. We also present a hardware/software co-design framework, which provides high-speed communication between the CPU and the FPGA connected by PCIe standard interface provided by the RIFFA driver [1]. For proof of concept, the proposed polynomial multiplier is deployed in this framework to accelerate the decryption operation of Brakerski/Fan-Vercauteren (BFV) homomorphic encryption scheme implemented in Simple Encrypted Arithmetic Library (SEAL), by the Cryptography Research Group at Microsoft Research [2]. In the proposed framework, polynomial multiplication operation in the decryption of the BFV scheme is offloaded to the accelerator in the FPGA via PCIe bus while the rest of operations in the decryption are executed in software running on an off-the-shelf desktop computer. The hardware part of the proposed framework targets Xilinx Virtex-7 FPGA device and the proposed framework achieves the speedup of almost 7 × in latency for the offloaded operations compared to their pure software implementations, excluding I/O overhead. 相似文献
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为了适应未来嵌入式快速发展的要求,提出了一种基于Xilinx FPGA利用片上可编程系统(system on a programmable chip,SOPC)技术实现大量数据的CF卡(compact flash)存储以及使用轻型IP协议(light weight IP,LwIP)进行数据传输的方法.对整个系统的硬件结构,Xilinx SOPC开发工具、流程和采用的关键技术进行了介绍.在此基础上应用Xilinx的嵌入式开发套件,以Xilinx公司提供的知识产权(intellectual property,IP)核为基础,搭建了一个SOPC平台.通过将CF卡、LwIP协议应用于软件设计中,实现了驱动程序和应用程序的开发,并通过与上位机进行通信测试,测试结果表明了该设计的可行性和有效性. 相似文献
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This paper proposes a new approach, named Card-Aided Firewall (CAF) that combines the simplified firewall and the state-oriented smart card technologies to construct a controllable and accountable Internet access framework. The idea suggests that a client computer, protected by a light-weight firewall, could establish diversified authenticated communication channels, controlled and accounted by “legal” states of the smart card.The program of a smart card is state-oriented or a state machine, which defines a chain of events involving various state transitions. The “legal” states of a smart card program are defined to be legal to communicate with surfing targets. A predefined Access Control List (ACL), stored in the same card, is necessary. An ACL is a sequential list of permit or deny statements that apply to addresses or upper-layer protocols. The proposed firewall decides acceptance or rejection messages by matching the current state of the card program and the ACL. In addition, a complete surfing account for tracing back is recorded. It is a by-product of the smart card authentication.The proposed Card-Aided Firewall framework is implemented to demonstrate its effectiveness. The implementation is done at the driver level. It keeps up with the high line speed. The driver takes 39K bytes and works well with other firewalls. The average packet processing time of the CAF driver is 31.74 μs. On the premise of secure authentication within the smart card, the Card-Aided Firewall would facilitate various rapidly growing applications in campus cards, family cards, and employee cards, etc. that require accurate controllability and accountability in the surfing boundary. 相似文献
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中国矿业大学(北京校区)研制的强力输送带全断面实时透视仪,最初在386微机中采用了特制的图象处理卡VP12,并配有专用图象监视器CASPER,后来采用了ET6000显卡,皮带图象可直接在微机屏幕上显示。由于微机更新换代极快,一年后该显卡在市场上已很难买到,只好改为Trident9685显卡,而后又改用TNT2型等。每改换一次显卡,必须找出现卡驱程的原代码,从新编写显程,而原代码又很难找到。为了避免这种麻烦,采用了VBE标准编程,只要修改显卡的设置模式序号,程序就不用改写。本文详述了这一研制情况。 相似文献
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介绍了基于接口芯片CH365设计的数字I/O卡.在Windows操作系统下实现该PCI接口设备的驱动程序架构,给出了利用DriverWorks开发WDM(Win32 Driver Model)驱动程序的主要过程.本设计现在已经广泛应用在我国铁路THDS-A型红外线轴温探测系统中. 相似文献
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基于WDM的冗余设备驱动模型设计 总被引:1,自引:0,他引:1
随着计算机技术的发展,冗余技术成为提高计算机系统可靠性的有效方法之一;文中提出了一种基于WDM的冗余设备驱动模型,该模型可用在实现PCI设备的故障检测或冗余设备驱动设计中,具有一定的通用性;重点介绍了此驱动模型的基本结构和实现,并利用此模型设计双冗余CAN卡驱动和双冗余网卡驱动,给出了其冗余部分的设计流程;通过对CAN卡驱动与网卡驱动的冗余切换功能测试,结果表明此模型可实现实时总线故障情况下的冗余切换,证明了此模型在提高系统级可靠性方面具有一定的实用价值。 相似文献