FREQUENCY OVERSHOOT AND VOLTAGE DROOP MITIGATION APPARATUS AND METHOD

An apparatus and method are described, which prior to an event that could result in frequency overshoot, sends a signal to a voltage regulator or generator requesting a temporary supply voltage and/or current boost. This enables a clocking source, such as a phase locked loop (PLL) to lock fast while not needing any long-term voltage guard bands. The apparatus and scheme allows for on-the-fly change in supply voltage and/or clock frequency for a processor with little to no impact on Vmin. During the clock frequency overshoot, the supply voltage is temporarily boosted and then reduced down to the expected voltage level of the power supply. Such boost allows for absorbing the clock frequency overshoot impact. The supply voltage level can be reduced in a step-wise fashion to avoid any potential undershoot in clock frequency.