Power dissipation in NoC repeaters under random dopant fluctuations

Power dissipation has been pointed out as the main limiting factor for the scaling of future CMOS circuits. Due to technology scaling, a large number of repeaters are being used in on-chip communication networks and they contribute a significant portion of the total chip power. Therefore, in this work we have characterized the leakage, short circuit and switching power dissipation for the repeaters of 25, 18 and 13 nm future technology generations, in the presence of random dopant fluctuations. The results confirm that, due to technology scaling, the leakage power is becoming a major component of power dissipation. The distribution of this power has not been previously studied, and we found that it is greatly asymmetric about the mean, rather more than the delay distribution, due to variability in the devices. Its implication is that some of the devices could even dissipate more than 340% of the mean power and thus further reduces the yield due to unacceptable power losses for the devices which are otherwise delay efficient. It is therefore possible that localized heating, and variations in characteristics introduced by it, could affect the reliability of the system, although further characterization is necessary to determine the magnitude of these effects in system performance. The results of this study can be very useful for the designers devising power efficient circuit methodologies and other countermeasure approaches.