Patent ID: 9310783
Filing Date: 2016-04-12
CPC Classification: G05B,G06F,Y02D

Claim Text:
1. An apparatus comprising: a first functional unit of an integrated circuit (IC), the first functional unit being coupled to a first communications link, the first communications link being one of a plurality of communications links; and a second functional unit of the IC, wherein the second functional unit is configured to communicate with the first functional unit via the first communication link, wherein the first and second functional units are part of a plurality of functional units, wherein each of the plurality of functional units is coupled to at least one other one of the plurality of functional units by a unique one of the plurality of communications links; wherein the second functional unit is configured to enter a low power state, and wherein the first functional unit is configured to transmit a request to communicate with the second functional unit when the second functional unit is in the low power state, and wherein the second functional unit is configured to exit the low power state responsive to receiving the request from the first functional unit; and wherein the apparatus further comprises a power management unit implemented on the IC and configured to power manage each of the plurality of functional units, wherein the power management unit includes a link state machine configured to monitor availability of each of the plurality of communications links; and wherein each of the plurality of functional units includes a local power management circuit configured to cause internal circuitry of its respective functional unit to enter a low power state based on communications with the power management unit; and wherein the local power management circuit of each of the plurality of functional circuit blocks is configured to send and receive wake-up requests directly from respective local power management circuits of each logically adjacent one of the plurality of functional circuit blocks, and further configured to wake internal circuitry of its respective one of the plurality of functional circuit blocks from the low power state, independent of the power management unit, responsive to receiving a wake-up request directly from local power management circuit of a logically adjacent one of the plurality of functional units.