Combined RFID and power management architecture

1. An integrated circuit product comprising:

an integrated circuit comprising:

an integrated circuit interface comprising a plurality of power supply input terminals, a plurality of power delivery terminals, and an energy harvest output terminal;

a wireless communications circuit configured to harvest energy received in a wireless communications signal and to provide harvested energy to the energy harvest output terminal;

a selection circuit coupled to the integrated circuit interface and configured to selectively provide power to the plurality of power delivery terminals based on power received from the plurality of power supply input terminals in response to a control signal; and

a control circuit configured to generate the control signal based on a first level of the harvested energy, any signals received on the plurality of power supply input terminals, and predetermined rules,

wherein the control circuit configures the selection circuit to provide power to a first set of circuits of a first power domain based on a first predetermined event of the predetermined rules,

wherein the control circuit configures the selection circuit to provide power to a second set of circuits of a second power domain based on a second predetermined event of the predetermined rules, and

wherein the control circuit configures the selection circuit to provide power to a third set of circuits of a third power domain based on a third predetermined event of the predetermined rules.

2. The integrated circuit product, as recited in claim 1 , further comprising:

a reservoir configured to receive the harvested energy from the energy harvest output terminal, to store the harvested energy, and to deliver power to a corresponding power supply input terminal of the plurality of power supply input terminals,

wherein the selection circuit receives power from the reservoir via the corresponding power supply input terminal.

3. The integrated circuit product, as recited in claim 1 , further comprising:

a controller unit coupled to a corresponding power delivery terminal of the plurality of power delivery terminals,

wherein the integrated circuit further comprises a non-volatile memory, and

wherein the wireless communications circuit is configured to access the non-volatile memory while the controller unit is powered off.

4. The integrated circuit product, as recited in claim 3 , wherein the integrated circuit further comprises:

a communications interface coupled to the wireless communications circuit and the control circuit, the communications interface being configured to communicate between the integrated circuit and the controller unit.

5. The integrated circuit product, as recited in claim 3 , further comprising:

a component coupled to a second corresponding power delivery terminal of the plurality of power delivery terminals.

6. The integrated circuit product, as recited in claim 1 , further comprising:

a secondary power source coupled to a power supply input terminal of the plurality of power supply input terminals, wherein the control circuit is configured to monitor a power level of the secondary power source.

7. The integrated circuit product, as recited in claim 1 , wherein the wireless communications signal comprises signals having frequencies in a Radio-Frequency Identification

(RFID) frequency band and the wireless communications circuit detects the wireless communications signal in a near field region.

8. The integrated circuit product, as recited in claim 1 , wherein the predetermined rules include transitioning a power state of the integrated circuit in response to a

first level of available power exceeding a first predetermined power level and the first level of

available power being less than a second predetermined power level.

9. A method for operating an integrated circuit system comprising:

selectively providing power to at least one power supply delivery terminal of a plurality of power delivery terminals based on power received from at least one power supply input terminal of a plurality of power supply input terminals in response to a control signal; and

generating the control signal by a control circuit based on a first level of harvested energy harvested from a wireless communications signal received by a wireless communications circuit, any power received on the plurality of power supply input terminals, and predetermined rules,

wherein power is selectively provided to a first set of circuits of a first power domain based on a first predetermined event of the predetermined rules,

wherein power is selectively provided to a second set of circuits of a second power domain based on a second predetermined event of the predetermined rules, and

wherein power is selectively provided to a third set of circuits of a third power domain based on a third predetermined event of the predetermined rules.

10. The method, as recited in claim 9 , wherein the selectively providing power includes providing power to a first power delivery terminal of the plurality of power delivery terminals, the first power delivery terminal being coupled to a controller unit, the method further

comprising:

waking the controller unit from an unpowered state; and

communicating with the controller unit by the wireless communications circuit and the control circuit using a shared communications interface.

11. The method, as recited in claim 9 , further comprising:

waking the control circuit from an unpowered state in response to receiving the wireless communication signal;

harvesting power from the wireless communications signal;

storing the harvested power in a reservoir coupled to an energy harvest output terminal; and

receiving power from the reservoir using a power supply input terminal of the plurality of power supply input terminals.

12. The method, as recited in claim 11 , further comprising:

communicating a power level of the reservoir and presence of any signals received on the

plurality of power supply input terminals externally to the integrated circuit system.

13. The method, as recited in claim 11 , wherein the first predetermined event includes a power level of the reservoir and any signals received on the plurality of power supply

input terminals exceeding a first threshold power level and being below a second threshold

power level.

14. The method, as recited in claim 13 , wherein the second predetermined event includes the power level of the reservoir and any signals received on the plurality of power supply input terminals exceeding the second threshold power level and being below a third

threshold power level.

15. The method, as recited in claim 14 , wherein the second predetermined event includes the power level of the reservoir and any signals received on the plurality of power supply input terminals exceeding the third threshold power level.

16. The method, as recited in claim 9 , further comprising:

accessing a non-volatile memory while a controller unit is powered off.

17. An integrated circuit system comprising:

a plurality of power supply input terminals;

a plurality of power delivery terminals;

a storage element;

a switching circuit responsive to a control signal to couple a reservoir or a secondary power source to provide power using the plurality of power supply input terminals and the plurality of power delivery terminals; and

a processor configured to execute instructions stored in the storage element, the instructions being executable by the processor to cause the processor to:

generate the control signal based on a first level of harvested energy harvested from a wireless communications signal received by a wireless communications circuit, any power received on the plurality of power supply input terminals, and predetermined rules,

wherein the control signal configures the switching circuit to provide power to a first set of circuits of a first power domain based on a first predetermined event of the predetermined rules,

wherein the control signal configures the switching circuit to provide power to a second set of circuits of a second power domain based on a second predetermined event of the predetermined rules, and

wherein the control signal configures the switching circuit to provide power to a third set of circuits of a third power domain based on a third predetermined event of the predetermined rules.

18. The integrated circuit system, as recited in claim 17 , further comprising:

the reservoir; and

the secondary power source,

wherein the first set of circuits includes circuits within the wireless communications circuit that are used to access a non-volatile memory, and

wherein the second set of circuits includes an external controller unit.

19. The integrated circuit system, as recited in claim 18 , further comprising:

the wireless communications circuit configured to harvest energy from the wireless communications signal,

wherein the external controller unit is coupled to a corresponding power delivery terminal of the plurality of power delivery terminals,

wherein the wireless communication circuit is configured to access non-volatile memory while the external controller unit is powered off based on a communication received via the wireless communications circuit.