Per-Core DVFS With Switched-Capacitor Converters for Energy Efficiency in Manycore Processors

Author

Jevtic, Ruzica ; Hanh-Phuc Le ; Blagojevic, Milovan ; Bailey, Stevo ; Asanovic, Krste ; Alon, Elad ; Nikolic, Borivoje

Author_Institution

Dept. of Electr. Eng. & Comput. Sci., Univ. of California at Berkeley, Berkeley, CA, USA

Volume

23

Issue

4

fYear

2015

fDate

Apr-15

Firstpage

723

Lastpage

730

Abstract

Integrating multiple power converters on-chip improves energy efficiency of manycore architectures. Switched-capacitor (SC) dc-dc converters are compatible with conventional CMOS processes, but traditional implementations suffer from limited conversion efficiency. We propose a dynamic voltage and frequency scaling scheme with SC converters that achieves high converter efficiency by allowing the output voltage to ripple and having the processor core frequency track the ripple. Minimum core energy is achieved by hopping between different converter modes and tuning body-bias voltages. A multicore processor model based on a 28-nm technology shows conversion efficiencies of 90% along with over 25% improvement in the overall chip energy efficiency.

Keywords

CMOS integrated circuits; DC-DC power convertors; circuit tuning; microprocessor chips; multiprocessing systems; switched capacitor networks; CMOS process; SC DC-DC converter; body-bias voltage tuning; converter mode hopping; core energy; dynamic voltage and frequency scaling; energy efficiency; manycore processor; multicore processor model; multiple power converter on-chip; per-core DVFS; processor core frequency; size 28 nm; switched-capacitor converter; voltage ripple; Adaptation models; Clocks; Integrated circuit modeling; Load modeling; Mathematical model; Program processors; Switches; Dynamic voltage and frequency scaling (DVFS); multicore processors; switched capacitor (SC); switched capacitor (SC).;

fLanguage

English

Journal_Title

Very Large Scale Integration (VLSI) Systems, IEEE Transactions on

Publisher

ieee

ISSN

1063-8210

Type

jour

DOI

10.1109/TVLSI.2014.2316919

Filename

6815766