Variation tolerant NoC design by means of self-calibrating links

We present the implementation and analysis of a variation tolerant version of a switch-to-switch link in a NoC. The goal is to tolerate the effects of process variations on NoC architectures using self-correcting links that automatically detect delay variations and compensate them. The correction is applied without increasing the switch-to-switch latency by substituting the output flip-flops of the sending switch with a self-correcting flip-flop followed by an adaptive voltage swing selector. Higher delay variations will result in a smaller slack in the switch-to-switch path, but the adaptive voltage swing selector could mitigate its impact on the NoC communication by increasing the voltage swing on the link, thus allowing a compensation of the delay variation. As a result, it is possible to tolerate delay variations at the cost of additional power consumption.