Design and Performance Parameters of an Ultra-Low Voltage, Single Supply 32bit Processor Implemented in 28nm FDSOI Technology

Sylvain Clerc1,  Fady Abouzeid1,  Darayus Adil Patel1,  Jean-Marc Daveau1,  Cyril Bottoni1,  Lorenzo Ciampolini1,  Fabien Giner1,  David Meyer1,  Robin Wilson1,  Philippe Roche1,  Sylvie Naudet1,  Arnaud Virazel2,  Alberto Bosio2,  Patrick Girard2
1STMicroelectronics, 2LIRMM


Abstract

This work presents a single-supply SPARC 32b V8 microprocessor designed with Ultra Low Voltage (ULV) adapted standard cells and memories, aiming at low energy operation and stand by power. The microprocessor, equipped with 10 Transistors ULV bitcell 8KB SRAM cache, has been fabricated in Fully Depleted Silicon On Insulator (FDSOI) 28nm technology. A comparative analysis with similar implementations has been provided highlighting the performance gain and power savings that are achieved by our design methodology and implementation technology. Wafer-level tests showed that our ULV adapted microprocessor has an operating range that is functional down to 0.33V and that the ULV able cache can save from 30% to 62% energy.