Paper Info
Title
Voltage-Stacked Power Delivery Systems: Reliability, Efficiency, and Power Management
Abstract
In today's manycore processors, the energy loss of more than 20% may result from inherent inefficiencies of conventional power delivery system (PDS) design. By stacking multiple voltage domains in series to lower the step-down conversion ratio of the off-chip voltage regulator module (VRM) and reduce the energy loss along the path of the power delivery network (PDN), voltage stacking (VS) offers a novel alternative power delivery technique to fundamentally improve power delivery efficiency (PDE). However, VS suffers from aggravated supply voltage noise from the current imbalance, which hinders its adoption. In this article, we investigate practical VS implementation in manycore processors to improve PDE and achieve reliable performance, while maintaining compatibility with advanced power management techniques. We first present the system configuration of a voltage-stacked manycore processor. We then systematically characterize supply voltage noise in VS, identify global, and residual differential currents as its dominant contributors, and calculate the possible worst supply voltage noise. We next propose a hybrid voltage regulation solution, based on a charge-recycling off-chip voltage regulator and distributed integrated voltage regulators, to mitigate supply voltage noise effectively. We also study the compatibility of VS with higher-level power management techniques. Finally, the performance of a voltage-stacked GPU system is comprehensively evaluated. The simulation results show that our approach can achieve 93.5% PDE, reducing the power loss by 13.6% compared to conventional single-layer PDS.
Year
DOI
Venue
2020
10.1109/TCAD.2020.2969607
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Keywords
DocType
Volume
Integrated voltage regulator,manycore architecture, power delivery system (PDS),supply noise,voltage stacking (VS)
Journal
39
Issue
ISSN
Citations 
12
0278-0070
2
PageRank 
References 
Authors
0.39
0
7
Name
Order
Citations
PageRank
An Zou172.12
Jingwen Leng232711.55
Xin He38028.00
Yazhou Zu4405.20
Christopher D. Gill578955.35
Vijay Janapa Reddi62931140.26
xuan zhang79325.30