Textbook in PDF format

This document defines the “base” specification for the PCI Express architecture, including the electrical, protocol, platform architecture and programming interface elements required to design and build devices and systems. A key goal of the PCI Express architecture is to enable devices from different vendors to inter-operate in an open architecture, spanning multiple market segments including clients, servers, embedded, and communication devices. The architecture provides a flexible framework for product versatility and market differentiation.
This specification describes the PCI Express architecture, interconnect attributes, fabric management, and the programming interface required to design and build systems and peripherals that are compliant with the PCI Express Specification.
The goal is to enable such devices from different vendors to inter-operate in an open architecture. The specification is intended as an enhancement to the PCI architecture spanning multiple market segments; clients (desktops andmobile), servers (standard and enterprise), and embedded and communication devices. The specification allows system OEMs and peripheral developers adequate room for product versatility and market differentiation without the burden of carrying obsolete interfaces or losing compatibility