Effectiveness of adaptive supply voltage and body bias as post-silicon variability compensation techniques for full-swing and low-swing on-chip communication channels

Adaptive body bias (ABB) and adaptive supply voltage (ASV) have been showed to be effective methods for post-silicon tuning of circuit properties to reduce variability. While their properties have been compared on generic combinational circuits or microprocessor circuit sub-blocks, the advent of multi-core systems is bringing a new application domain forefront. Global interconnects are evolving to complex communication channels with drivers and receivers, in an attempt to mitigate the effects of reverse scaling and reduce power. The characterization of the performance spread of these links and the exploration of effective and power-aware compensation techniques for them is becoming a key design issue. This work compares the variability compensation efficiency of ABB vs ASV when put at work in two representative link architectures of today´s ICs: a traditional full-swing interconnect and a low-swing signaling scheme for low-power communication. We provide guidelines for the post-silicon variability compensation of these communication channels.