A method and apparatus for interfacing dynamic hardware power managed blocks and software power managed blocks is disclosed. In one embodiment, and integrated circuit (IC) may include a number of power manageable functional units. The functional units maybe power managed through hardware, software, or both. Each of the functional units may be coupled to at least one other functional unit through a direct communications link. A link state machine may monitor each of the communications links between functional units, and may broadcast indications of link availability to the functional units coupled to the link. Responsive to a software request to shut down a given link, or a hardware initiated shutdown of one of the functional units coupled to the link, the link state machine may broadcast and indication that the link is unavailable.