The buffer availability has been split into three individual signals for the AXI4-Stream (Enhanced) Requester Request interface.
• pcie_tfc_nph_av indicates the currently available header credit for non-posted TLPs on the transmit side of the core.
• pcie_tfc_npd_av indicates the currently available payload credit for non-posted TLPs on the transmit side of the core.
• pcie_rq_tag_av indicates the currently available header credit for non-posted TLPs on the transmit side of the core.