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1.
LVDS高速I/O接口电路设计   总被引:8,自引:0,他引:8  
提出了一种用于传输高速数据的LVDS(Low Voltage Differential Signaling)驱动器及接收器的设计.基于MOS管的大信号模型计算了电路的参数,根据TSMC(台积电)的0.25μmCMOS工艺模型,在Candence环境下用Spectre仿真器模拟,调整各个MOS管的宽长比,确定了电路各参数.给出了驱动器和接收器互连的仿真结果,仿真结果表明该LVDS驱动器和接收器能稳定工作在1GHz的工作频率下,LVDS高速I/O接口电路能使计算机之间、芯片之间的数据传输带宽达到Gbit/s级.有广阔的应用前景。  相似文献   

2.
采用USB接口的设备越来越普遍,其主要原因在于USB设备连接简单,具备真正的即插即用以及热插拔等特点。Cypress半导体公司的CY7C63413USB控制器整合了USBSIE,通过I/O口以及优化RISCA内核,它满足了USB接口的低价格、高性能两方面的要求,采用它能快速设计出低成本、高性能的USB键盘。  相似文献   

3.
集群服务器系统前端接口子系统的设计与实现   总被引:1,自引:0,他引:1  
基于链路聚集技术,提出并实现了一种适用于集群服务器系统的前端接口子系统方案,使得接口子系统中的接口机数目能随应用规模的变化而扩展,并增强了集群系统的可用性.链路聚集将多条物理链路聚合成一条单一虚拟的媒体访问控制(MAC)逻辑链路,通过将虚拟MAC解析为集群系统对外服务的虚拟IP(VIP),使多台接口机表现为单一IP的功能.利用链路聚集能在多条物理链路间进行负载均衡的功能,结合接口机的负载均衡策略来实现层次型的负载均衡,有效地提高了系统的I/O带宽.利用链路聚集的链路级容错,结合接口的检测机制实现了系统的高可用功能.理论分析和实验测试结果均表明,该方案能有效扩展集群系统的I/O带宽和处理能力.  相似文献   

4.
分析了I2C总线的优点,时序和数据传输格式,利用单片机的I/O口线模拟I2C总线传输信息,以此来扩展单片机的I/O接口。  相似文献   

5.
对适配器驱动技术进行了研究,提出了一种可扩展的并行I/O方法.这种方法将多DMA通道和I/O接口集成到适配器中,可实现I/O命令的多通道并行处理,从而以较低代价实现外围设备I/O性能扩展.建立并行I/O的SPN模型,对这种结构下各I/O环节对设备栈I/O性能的影响进行了分析,重点研究I/O请求量与系统IRP流量和I/O通道利用率的关系,并结合测试数据对分析结论给予了证明.  相似文献   

6.
远程I/O系统是一种新型的控制系统,近几年来发展迅速,应用量越来越大,技术上有一定的先进性。文中简要介绍了远程I/O的发展历史和技术特点,通过对德国p f公司RPI和IS-RPI的具体分析,旨在使读者对远程I/O接口技术特点有一个清晰的认识和了解,最后对p f远程I/O接口与典型的DCS系统的通讯方式作了较详细的介绍。  相似文献   

7.
基于三星公司的S3C44BOX处理器的嵌入式开发平台,提出了一种用S3C44BOX的通用I/O口和中断源实现与PS/2键盘的接口设计方案,详细阐述了其硬件接口设计和软件设计的步骤,并用C语言编写了软件设计程序,以便移植到其它系统中。  相似文献   

8.
由于连接简单、真正的即插即用以及热插拔等特点,使用USB接口的设备越来越普遍.Cypress半导体公司的CY7C63000 USB控制器整合了USBSIE、通用I/O口以及USB优化RISC内核,它满足了USB的低价格、高性能两方面的要求,采用它能快速设计出低成本、高性能的USB光机鼠标.  相似文献   

9.
自制设计了一种MCS-51单片机接口实验板。利用它可以做存储器扩展、并行I/O扩展、串行通讯、A/D转换、D/A转换、键盘、LED显示、打印等多种单片机接口实验,弥补了传统的单板单用的不足,给出了其硬件组成及各种接口说明,并列出了实用主程序和接口子程序流程图。  相似文献   

10.
PCI总线接口设计及其专用芯片应用   总被引:1,自引:1,他引:1  
介绍了PCI总线结构和接口开发背景,并对专用接口芯片S5933芯片的工作原理,功能特点进行了分析,自行开发了一个具有实用价值的接口电路,该接口电路使用了可编程逻辑,FIFO存储等技术,既可以进行I/O操作,也可以通过DMA操作来传输高速的大容量数据,解决数据传输的瓶颈问题,应用结果表明,该电路工作稳定,性能突出,具有较高的性能价格比。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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