PCI Express Base Specification, Revision 2.1
= PCI Express Base Specification, Revision 2.1
{c}
{title2=2009}
https://www.intel.com/content/dam/support/us/en/programmable/support-resources/fpga-wiki/asset03/pci-express-base-r2.1.pdf
Section 1.3, figure 1-2