Runtime Resonance Noise Reduction with Current Prediction Enabled Frequency Actuator
Power delivery network (PDN) is a distributed resistance-in-ductance-capacitance (RLC) network with its dominant resonance frequency in the low-to-middle frequency range. Though high-performance chips' working frequencies are much higher than this resonance frequency in general, chip runtime loading frequency is not. When a chip executes a chunk of instructions repeatedly, the induced current load may have harmonic components close to this resonance frequency, causing excessive power integrity degradation. Existing PDN design solutions are, however, mainly targeted at reducing high-frequency noise and not effective to suppress such resonance noise. In this work, we propose a novel approach to proactively suppress this type of noise. A method based on the high dimension generalized Markov process is developed to predict current load variation. Based on such prediction, a clock frequency actuator design is proposed to proactively select an optimal clock frequency to suppress the resonance. To the best of our knowledge, this is the first in-depth study on proactively reducing instruction loop induced PDN resonance noise at the runtime.
resonance noise frequency actuator stochastic current modeling