Pcie completion header and data advertising infinite credits


Can anyone explain when there is no peer to peer communication supported by the pcie root complex the infinite credits are advertised and what happes in the root complex which supports the peer to peer communication in data link layer in the initialization time.

Also why the peer to peer communication is related to the completion header and data credits?


  • Hi,

    When PCIe root complex doesn't support peer-to-peer communication, it advertises infinite credits. In a root complex supporting peer-to-peer communication at the data link layer during initialization, it manages the process differently.

    Peer-to-peer communication is linked to completion header and data credits due to the nature of data transfer and acknowledgment mechanisms.