Leakage losses have become a significant portion of power consumption in nanoscale circuits. Power gating techniques are effective in mitigating these losses, especially for low duty cycle systems and pipelines. It is of particular importance to determine whether a pipeline is empty before power gating it. If tokens are still in flight and useful computation is still being performed, preemptively shutting off a pipeline could destroy state, data, and execution correctness. We propose an asynchronous constant-time counter for use in empty pipeline detection, assuming the power savings from power gating the pipeline amortize the additional power consumption of the counter.


Jonathan Tse and Derek Lockhart