Full-Chip Model for Leakage-Current Estimation Considering Within-Die Correlation

In this paper, we present an efficient technique for finding the mean and variance of the full-chip leakage of a candidate design, while considering logic structures and both die-to-die and within-die (WID) process variations, and taking into account the spatial correlation due to WID variations. Our model uses a ldquorandom-gaterdquo concept to capture high-level characteristics of a candidate chip design, which are sufficient to determine its leakage. These high-level characteristics include information about the process, the standard cell library, and expected design characteristics. We show empirically that, for large gate count, the set of all chip designs that share the same high-level characteristics have approximately the same leakage, with very small error. Therefore, our model can be used as either an early or a late estimator of leakage, with high accuracy. In its simplest form, we show that full-chip-leakage estimation reduces in finding the area under a scaled version of the WID channel length autocorrelation function, which can be done in constant time.