Introduction
Refer to Figure 20-1 on page 723. Each function implements a 4KB configuration space. The lower 256 bytes (64 dwords) is the PCI-compatible configuration space, while the upper 960 dwords is the PCI Express extended configuration space.
Figure 20-1. A Function's Configuration Space
There are two mechanisms available that allow configuration software running on the processor to stimulate the Root Complex to generate configuration transactions:
The PCI 2.3-compatible configuration access mechanism.
The PCI express enhanced configuration mechanism.
These two mechanisms are described in this chapter.
Intel x86 and PowerPC processors (as ...
Get PCI Express System Architecture now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
