Patent ID: 7603578

Claim:
A method for using a programmable system-on-a-chip including an analog-to-digital converter (ADC) to enable a plurality of power supply voltages comprising: enabling each of a plurality of power supplies, with each of the plurality of power supplies providing one of the plurality of power supply voltages, wherein the plurality of power supplies comprises: a first power supply providing a first power supply voltage and associated with a first power supply flag; and a second power supply providing a second power supply voltage and associated with a second power supply flag; setting each of a plurality of power supply flags to a first state, with each of the plurality of power supply flags having the first state and a second state, and each associated with a unique one of the plurality of power supplies; repeating a first loop until each of the plurality of power supply flags is in the second state, said first loop comprising: repeating a second loop for each of the power supplies as the current power supply, said second loop comprising: if the power supply flag associated with the current power supply is in the first state, then performing a block comprising: sampling a voltage for the current power supply as a sampled voltage; comparing the sampled voltage to a threshold voltage associated with the current power supply; setting the power supply flag associated with the current power supply to the second state if the sampled voltage exceeds the threshold voltage associated with the current power supply; after all of the plurality of power supply flags are in the second state, performing a third loop for each of the power supplies as a current power supply comprising: turn on a power MOSFET for the current power supply according to a programmed ramp rate for the current power supply.