Patent ID: 8232846

Claim:
An apparatus comprising: a current generator circuit configured to generate a current, wherein the current generator circuit comprises: a first inverter having an output coupled to a first terminal of a logic block; and a resistor coupled to an input of the first inverter and a second terminal of the logic block, wherein an input voltage of the first inverter equals the output voltage of the first inverter; a capacitor configured to be charged by the current; a second inverter including an input coupled to the capacitor, wherein an output of the second inverter goes to a first level when a voltage across the capacitor reaches a threshold voltage of the second inverter; a switch coupled to the output of the second inverter and the capacitor, the switch configured to move from a first position to a second position when the output of the second inverter goes to the first level thereby discharging the capacitor, wherein the output of the second inverter goes to a second level when the capacitor is discharged thereby causing the switch to move to the first position; and clock generator logic configured to receive the output of the second inverter and generate a clock signal, wherein the current generated by the current generator circuit is based on the threshold voltage of the second inverter and a resistance of the resistor.