The energy complexity of register files

  • Authors:
  • V. Zyuban;P. Kogge

  • Affiliations:
  • Computer Science & Eng. Department, University of Notre Dame, IN;Computer Science & Eng. Department, University of Notre Dame, IN

  • Venue:
  • ISLPED '98 Proceedings of the 1998 international symposium on Low power electronics and design
  • Year:
  • 1998

Quantified Score

Hi-index 0.01

Visualization

Abstract

Register files (RF) represent a substantial portion of the energybudget in modern processors, and are growing rapidly with the trendtowards wider instruction issue. The actual access energy costsdepend greatly on the register file circuitry used. This papercompares various RF circuitry techniques for their energy ef-ficiencies, as a function of architectural parameters such as thenumber of registers and the number of ports. The Port PrioritySelection technique was found to be the most energy efficient. Thedependence of register file access energy upon technology scalingis also studied. However, as this paper shows, it appears that noneof these will be enough to prevent centralized register files frombecoming the dominant power component of next-generationsuperscalar computers, and alternative methods forinter-instruction communication need to be developed. Splitregister file architecture is analyzed as a possible alternative.