Cross-domain power control circuit

A method comprising:

• generating, using a voltage regulator, a first supply voltage for a first power domain, wherein the first supply voltage is generated based on a second supply voltage of a second power domain, and wherein the first supply voltage is greater than the second supply voltage, wherein the first supply voltage is conveyed on a first supply voltage node and the second supply voltage is conveyed on a second supply voltage node;
• operating a power controller circuit in a first mode, wherein operating in the first mode comprises a control circuitry causing a first circuit branch of a cross-domain power circuit to activate a first transistor to convey the second supply voltage to a third supply voltage node;
• operating the power controller circuit in a second mode, wherein operating in the second mode comprises the control circuitry causing a second circuit branch of the cross-domain power circuit to activate a second transistor to convey the first supply voltage to the third supply voltage node;
• and
• operating the power controller circuit in a third mode, wherein operating the power controller circuit in the third mode comprises:
• causing the voltage regulator to power up the first supply voltage node to the first supply voltage using a power management circuit;
• asserting a control signal provided from the power management circuit to the control circuitry;
• deactivating the first transistor responsive to asserting the control signal, wherein deactivating the first transistor causes discontinuation of providing the second supply voltage to the third supply voltage node;
• activating the second transistor responsive to asserting the control signal;
• and causing the first supply voltage to be provided to the third supply voltage node responsive to activating the second transistor.

An integrated circuit comprising:

• a first power domain comprising circuitry coupled to receive a first supply voltage via a first supply voltage node;
• a second power domain comprising circuitry coupled to receive a second supply voltage via second supply voltage node;
• and
• a power controller circuit comprising a third supply voltage node, wherein the power controller circuit includes control circuitry configured to, when operating in a first mode, cause activation of a first transistor to convey the second supply voltage to a third supply voltage node, wherein the control circuitry is further configured to, when operating in a second mode, cause activation of a second transistor to convey the first supply voltage to the third supply voltage node;
• wherein the power controller circuit is further configured to operate in a third mode responsive to a power management circuit causing the first supply voltage node to be powered on and subsequently asserting a control signal to the control circuitry, wherein operating in the third mode comprises increasing a voltage present on the third supply voltage node from the second supply voltage to an intermediate voltage, and subsequently increasing the voltage on the third supply voltage node to the first supply voltage.