Interfacing Dynamic Hardware Power Managed Blocks and Software Power Managed Blocks

摘要

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.

主权项

1. An apparatus comprising:
first and second functional units of an integrated circuit configured to communicate with one another via a communications link, wherein a given one of the first and second functional units is unavailable for communications over the link when in a low power state; and a state machine coupled to each of the first and second functional units and configured to track an availability of each of the first and second functional units to communicate over the link, wherein the state machine is configured to broadcast a link availability indication to the first and second functional units, and wherein the first and second functional units are configured to control communications on the communications link responsive to the link availability indication.