SNLA415 August   2022 DS160PT801

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2History
  5. 3Components of PCIe Communication
    1. 3.1 Root Complex
    2. 3.2 Repeater
    3. 3.3 Endpoints
  6. 4Signaling
    1. 4.1 PERST
    2. 4.2 WAKE and CLKREQ
    3. 4.3 REFCLK
  7. 5Link Training
    1. 5.1 Receiver Detect (Rx Detect)
    2. 5.2 Polling
    3. 5.3 Configuration
  8. 6Link Equalization
    1. 6.1 Phase 0 and 1
    2. 6.2 Phase 2 and 3
  9. 7Summary
  10. 8References

3.1 Root Complex

A root complex is the interface between the system CPU, memory, and the rest of the PCIe interface. The root complex is either integrated into the CPU directly, or is external to the CPU as a discrete component. This interface also acts as a single source where all the data from various PCIe endpoints pass through. Figure 3-1 shows it as the dark blue box that connects CPU, memory, and PCIe components and is referred as "Root Complex."