This invention discloses a system and method for dynamically managing voltage and frequency in an integrated circuit (IC), comprising a plurality of ring oscillators for generating a plurality of continuous pulses with frequencies reflecting the process parameter, operating voltage and temperature effects in the IC, a period generator for generating at least one gating period with a predetermined duration, a plurality of counters coupling to the plurality of ring oscillators as well as the period generator for counting the number of the continuous pulses in the gating period, at least one selector for selecting a predetermined number counted by the plurality of counters, and at least one voltage-and-frequency adjustment circuitry for adjusting one or more operating voltages or one or more clock frequencies in the IC based on the predetermined number selected by the selector, wherein the IC operating voltage or clock frequency correlates with the ring oscillator frequencies.