Error-resilient sequential cells with successive time borrowing for stochastic computing

This paper presents error-resilient sequential building blocks with time-borrowing capability without extra latches and generated clocks. The circuits are able to recover the timing errors caused by PVT variations and/or over-voltage scaling by up to half a cycle. Unlike prior works, the timing errors can be recovered dynamically through successive time borrowing without stalled cycles, retaining a constant throughput. The circuit structure can be applied to both ASICs and microprocessors. The proposed sequential cells are highly compatible with current cell-based IC design flow, for both feedforward and feedback datapaths. As a proof of concept, a design with key DSP building blocks has been verified. The results show that the performance of the DSP modules is improved by 13-15% in the worst-case operation condition, yielding a promising solution for stochastic computing under an unreliable operation condition.