Blade-DA: Click-Based Asynchronous Resilient Circuit With Dynamic Delay Adjustment

Asynchronous resilient circuits have demonstrated higher efficiency and robustness due to their flexible local control mechanism and ability to eliminate metastability, compared to the synchronous resilient circuits. This article proposes the Blade-DA template, which is an asynchronous resilient circuit that incorporates a delay adjustment scheme. The Blade-DA template utilizes the Click template to simplify circuit design with a larger timing resilient window (TRW). Additionally, the Blade-DA template integrates a dynamic delay adjustment controller, which adaptively tunes the TRW based on real-time timing error rates. In this way, this controller reduces the timing error rate to improve performance under unfavorable process, voltage, and temperature (PVT) corners. Moreover, we propose an optimization method of adding extra constraints to change the delay distribution, which further improves the performance of Blade-DA template. Compared to the previous controller with a large TRW, the proposed asynchronous controller offers a significant 81.65% improvement in maximum frequency and a 61.93% reduction in area while operating at the same frequency. Furthermore, the Blade-DA template is applied to a three-stage RISC-V processor, resulting in a 7.92%-14.78% performance improvement under unfavorable PVT conditions compared to the fixed TRW asynchronous template, while incurring only a 1.63% additional area cost.