Prediction of maximum operating frequency for packaged microprocessor using measurements and modeling

This paper introduces a method to predict of the impact of packaging changes on microprocessor maximum operating frequency (Fmax). This is useful both in package technology selection and subsequent design optimization. The method uses power draw versus frequency and Fmax versus supply voltage data to enable time-domain circuit simulations using a resistive-acting dissipative core model instantiated within a field-solver-based model of the package. Measurements and simulations are carried out for an existing part that is packaged in a first, characterization package, in order to back out a theoretical intrinsic Fmax versus supply voltage curve for the package-free device. Subsequent circuit simulations using alternative package models can then be used to find the new Fmax for the device in a new package of interest that may not yet be fabricated. The method is useful for tasks such as predicting the outcome of reduced cost re-packaging of existing parts or estimating package effect on new similar parts in a family of parts.