Method and apparatus for on-demand power management

1. An apparatus comprising: a power management unit (PMU) to provide power to an electronic system, wherein the PMU resides on a first integrated circuit (IC) substrate; and a power management controller (PMC) residing on a second IC substrate distinct from the first IC substrate, the PMC coupled to the PMU to control values of one or more parameters of an operating state of the PMU in response to operating conditions of the electronic system, wherein the PMC is configured to execute a power management algorithm (PMA) to determine values of the one or more parameters, wherein the PMC comprises: a state machine to implement the PMA and to receive sense input signals from the electronic system; a programmable memory coupled to the state machine to store operating parameters of the PMU; a first bus interface coupled to the state machine, to communicate with the electronic system; and a second bus interface coupled to the state machine, to communicate with the PMU, and a processor coupled to the programmable memory, to execute the instructions of the PMA and to receive the sense input signals from the electronic system.

2. The apparatus of claim 1 , wherein the one or more parameters comprise at least one of a voltage, a frequency, or a control signal.

3. The apparatus of claim 1 , wherein the PMA comprises a lower envelope algorithm.

4. The apparatus of claim 1 , wherein the electronic system comprises a processor core and the PMA comprises external dynamic voltage scaling (DVS) of the processor core.

5. The apparatus of claim 1 , wherein the PMU controls at least one power domain of the electronic system, the at least one power domain comprising a plurality of power states, wherein the PMC selects one of the plurality of power states based on the operating conditions of the electronic system according to the PMA and causes the PMU to enter into the selected one of the plurality of power states.

6. A system comprising the apparatus of claim 1 , further comprising:

the electronic system, wherein the PMC is a separate from the electronic system; and

a communication bus coupled between the electronic system and the PMC.

7. A method comprising: providing power to an electronic system via a power management unit (PMU); and executing a power management algorithm (PMA) on a power management controller (PMC) to determine values of one or more parameters of an operating state of the PMU in response to operating conditions of the electronic system, wherein the PMC is a separate from the electronic system.

8. The method of claim 7 , wherein executing the PMA on the PMC comprises:

receiving sense input signals from the electronic system at a state machine of the PMC; and

executing the state machine in response to the sense input signals to determine a power state of the PMU.

9. The method of claim 7 , wherein the one or more parameters comprise at least one of a voltage, a frequency, or a control signal.

10. The method of claim 7 , wherein the PMA comprises a lower envelope algorithm.

11. The method of claim 7 , wherein the electronic system comprises a processor core and the PMA comprises external dynamic voltage scaling (DVS) of the processor core.

12. The method of claim 7 , wherein providing power to the electronic system via the PMU comprises:

using the PMU to control at least one power domain of the electronic system, the at least one power domain comprising a plurality of power states.

13. The method of claim 12 , further comprising:

using the PMC to select one of the plurality of power states for the PMU based on the operating conditions of the electronic system according to the PMA.

14. A non-transitory machine-readable medium that provides instructions that, when executed by a power management controller (PMC), will cause the PMC to perform operations comprising:

executing a power management algorithm (PMA) to determine values of one or more parameters of an operating state of a power management unit (PMU) in response to operating conditions of an electronic system, wherein the PMA implements dynamic voltage scaling of a processor core of the electronic system; and causing the PMU to enter into the operating state, wherein the PMU provides power to the electronic system, and receiving sense input signals from the electronic system at a processor of the PMC; the processor retrieving instructions of the PMA from a programmable memory of the PMC; and the processor executing the instructions of the PMA to determine a power state of the PMU based on the sense input signals.

15. The non-transitory machine-readable medium of claim 14 , wherein the operations further comprise:

receiving sense input signals from the electronic system at a state machine of the PMC; and

executing the state machine in response to the sense input signals to determine a power state of the PMU.

16. The non-transitory machine-readable medium of claim 14 , wherein the one or more parameters comprise at least one of a voltage, a frequency, or a control signal.

17. The non-transitory machine-readable medium of claim 14 , wherein the PMA comprises a lower envelope algorithm.

18. The non-transitory machine-readable medium of claim 14 , wherein the operations further comprise:

using the PMU to control at least one power domain of the electronic system, the at least one power domain comprising a plurality of power states.

19. The non-transitory machine-readable medium of claim 18 , wherein the operations further comprise:

causing the PMC to select one of the plurality of power states for the PMU based on the operating conditions of the electronic system according to the PMA.