PCI-Express技术详解:从历史到未来

4星 · 超过85%的资源 需积分: 48 97 下载量 159 浏览量 更新于2024-07-29 4 收藏 356KB PDF 举报
"该资源为PCI-Express规范的中文详细文档,涵盖了PCI-E技术的各个方面,包括其发展历史、技术优势、系统架构、物理层、数据链路层、处理层、软件层以及物理结构设计等内容,是相关开发人员的重要参考资料。" PCI-Express,简称PCIe,是计算机内部总线技术的革新者,由Intel最初提出并开发,后演变为行业标准。自1991年PCI标准诞生以来,经过多次迭代,逐渐发展出更高速、低延迟的PCIe总线技术。PCIe技术的优势在于其点对点连接方式,相比传统的共享总线架构,提供了更高的带宽和更低的延迟,使得数据传输效率显著提升。 在系统架构方面,PCIe总线分为四个主要层次:物理层(Physical Layer)、数据链路层(Link Layer)、处理层(Transaction Layer)和软件层(Software Layer)。物理层负责电气和机械接口,确保数据传输的可靠性;数据链路层则管理错误检测和校正,确保数据包在通道上的无差错传输;处理层负责将PCI总线事务转化为可以在数据链路层上传输的数据包;而软件层则涉及驱动程序和操作系统层面的支持,确保系统的兼容性和管理功能。 在物理结构部分,PCIe接口有多种规格,如PCIe x1、x2、x4、x8、x16等,对应不同的带宽需求。台式机PCIExpress物理接口设计规范详细定义了接口的物理尺寸、引脚定义以及电气特性,确保设备的互操作性。 PCI-Express的出现,不仅提升了数据传输速度,还优化了系统资源的利用,尤其在图形处理、存储设备、网络通信等领域有着广泛的应用。随着技术的进步,PCIe标准也在持续升级,如PCIe 4.0、5.0,带宽进一步翻倍,为高性能计算和大数据时代提供了坚实的基础。 PCI-Express规范中文版详细解读了PCI-E的技术背景、架构原理和物理设计,对于从事相关硬件开发、系统设计和优化的专业人员来说,是不可或缺的学习和参考材料。通过深入理解这些内容,可以更好地设计和利用PCI-Express接口,提高系统的性能和效率。
2009-08-26 上传
PCI EXPRESS 板卡设计指南: 1. Physical Interconnect Layout Design................................................ 5 1.1 Introduction ........................................................................................................ 5 1.2 Topology and Interconnect Overview .............................................................. 5 1.2.1 Card Interoperability ............................................................................................... 7 1.2.2 Bowtie Topology Considerations ............................................................................ 7 1.2.2.1 Lane Polarity Inversion.................................................................................................... 8 1.2.2.2 Lane Reversal and Width Negotiation ............................................................................. 8 1.3 Physical Layout Design Constraints............................................................... 11 1.3.1 PCB Stackup.......................................................................................................... 11 1.3.1.1 Desktop System Board and Add-in Card (4-layer) Stackup .......................................... 12 1.3.1.2 Server, Workstation and Mobile (6-layer, 8-layer and 10-layer) Stackups.................... 15 1.3.1.3 Add-in Card and Mobile (6-layer) Stackup ................................................................... 16 1.3.2 PCB Trace and Other Element Considerations ..................................................... 17 1.3.2.1 Differential Pair Width and Spacing Impacts ................................................................ 20 1.3.2.2 Differential Pair Length Restrictions and Budgets ........................................................ 23 1.3.2.3 Length Matching............................................................................................................ 24 1.3.2.4 Reference Planes............................................................................................................ 25 1.3.2.5 Breakout Area Specific Routing Guidelines .................................................................. 27 1.3.2.6 Edge Finger Design: Add-in Card ................................................................................. 29 1.3.2.7 Via Usage and Placement .............................................................................................. 30 1.3.2.8 Bends ............................................................................................................................. 32 1.3.2.9 Test Points and Probing ................................................................................................. 35 1.3.3 PCI Express Topologies ........................................................................................ 35 1.3.3.1 Interconnect Topologies for Two Components on the Baseboard ................................. 36 1.3.3.2 Interconnect Topologies for Baseboard with Add-in Card ............................................ 37 1.3.4 Passive Components and Connectors .................................................................... 38 1.3.4.1 AC Coupling Capacitors ................................................................................................ 38 1.3.4.2 Connectors ..................................................................................................................... 40 1.4 Summary........................................................................................................... 41
2014-09-15 上传
Traditional multi-drop, parallel bus technology is approaching its practical performance limits. It is clear that balancing system performance requires I/O bandwidth to scale with processing and application demands. There is an industry mandate to re-engineer I/O connectivity within cost constraints. PCI Express comprehends the many I/O requirements presented across the spectrum of computing and communications platforms, and rolls them into a common scalable and extensible I/O industry specification. Alongside these increasing performance demands, the enterprise server and communications markets have the need for improved reliability, security, and quality of service guarantees. This specification will therefore be applicable to multiple market segments. Technology advances in high-speed, point-to-point interconnects enable us to break away from the bandwidth limitations of multi-drop, parallel buses. The PCI Express basic physical layer consists of a differential transmit pair and a differential receive pair. Dual simplex data on these point-to-point connections is self-clocked and its bandwidth increases linearly with interconnect width and frequency. PCI Express takes an additional step of including a message space within its bus protocol that is used to implement legacy “side- band” signals. This further reduction of signal pins produces a very low pin count connection for components and adapters. The PCI Express Transaction, Data Link, and Physical Layers are optimized for chip-to-chip and board-to-board interconnect applications. An inherent limitation of today’s PCI-based platforms is the lack of support for isochronous data delivery, an attribute that is especially important to streaming media applications. To enable these emerging applications, PCI Express adds a virtual channel mechanism. In addition to use for support of isochronous traffic, the virtual channel mechanism provides an infrastructure for future extensions in supporting new applications. By adhering to the PCI Software Model, today’s applications are easily migrated even as emerging applications are enabled.