The capability of accurately estimating an upper bound of the maximum current drawn by a digital macroblock from the ground or power supply line constitutes a major asset of automatic power-gating flows. In fact, the maximum current information is essential to properly size the sleep transistor in such a way that speed degradation and signal integrity violations are avoided. Loose upper bounds can be determined with a reasonable computational cost, but they lead to oversized sleep transistors. On the other hand, exact computation of the maximum drawn current is an NP-hard problem, even when conservative simplifying assumptions are made on gate-level current profiles. In this paper, we present a scalable algorithm for tightening upper bound computation, with a controlled and tunable computational cost. The algorithm exploits state-of-the-art commercial timing analysis engines, and it is tightly integrated into an industrial power-gating flow for leakage power reduction. The results we have obtained on large circuits demonstrate the scalability and effectiveness of our estimation approach.
Titolo: | Fast Computation of Discharge Current Upper Bounds for Clustered Power Gating |
Autore/i: | Sathanur A.; BENINI, LUCA; Macii A.; Macii E.; Poncino M. |
Autore/i Unibo: | |
Anno: | 2011 |
Rivista: | |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1109/TVLSI.2009.2029276 |
Abstract: | The capability of accurately estimating an upper bound of the maximum current drawn by a digital macroblock from the ground or power supply line constitutes a major asset of automatic power-gating flows. In fact, the maximum current information is essential to properly size the sleep transistor in such a way that speed degradation and signal integrity violations are avoided. Loose upper bounds can be determined with a reasonable computational cost, but they lead to oversized sleep transistors. On the other hand, exact computation of the maximum drawn current is an NP-hard problem, even when conservative simplifying assumptions are made on gate-level current profiles. In this paper, we present a scalable algorithm for tightening upper bound computation, with a controlled and tunable computational cost. The algorithm exploits state-of-the-art commercial timing analysis engines, and it is tightly integrated into an industrial power-gating flow for leakage power reduction. The results we have obtained on large circuits demonstrate the scalability and effectiveness of our estimation approach. |
Data prodotto definitivo in UGOV: | 2013-06-27 15:18:17 |
Appare nelle tipologie: | 1.01 Articolo in rivista |