SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
I/O traffic is not symmetrical: it can only be requested by the RC, and responded to by the EP. It is a mostly deprecated feature of PCI, and could be replaced by Memory traffic. However, it is still required by the standard for a PCIe RC. It is supported by the current controller in both RC (requester) and legacy EP mode (completer).