SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
The PIPE interfaces the MAC, or controller, above PIPE in the protocol hierarchy and the PHY, or transceiver, below PIPE. The current controller implementation has a PIPE interface at its boundary.
The physical layer as defined by the PCIe standard extends into the PCIe MAC layer, to include, for example, the LTSSM, so that “physical layer” and PHY do not coincide, with the latter included in the former.
The PIPE interface has its own power state, driven by the PCIe controller towards PCIe_SS PHY on a 2-bit powerdown signal, depending on the PM state machines above. It has four states: P0, P0s, P1, P2: