An Adaptive Clock Duty-Cycle Controller to Mitigate Aging-Induced Clock Duty-Cycle Distortion in Automotive and IoT Processors

An adaptive clock duty-cycle controller (DCC) mitigates the adverse effect of aging-induced clock duty-cycle distortion (DCD) on the minimum supply voltage ( $V_{\text {MIN}}$ ) of high-performance automotive and Internet of Things (IoT) processors. The all-digital DCC measures the DCD from a clock-leaf node with a duty-cycle monitor (DCM). The DCM interfaces with an adaptive control to configure a duty-cycle adjuster (DCA). The DCA adapts the duty cycle at the clock-root node to compensate for the DCD at the clock-leaf nodes. A 3-nm test chip integrates the DCC into the clock path of a high-performance, industry-level neural processing unit (NPU) matrix-multiplication unit (MXU). Silicon measurements validate the DCC system with a self-checking test, as required for automotive processor safety compliance. Silicon accelerated-stress test-chip measurements demonstrate the DCC restoring the clock duty cycle from aging-induced clock DCD and the corresponding MXU $V_{\text {MIN}}$ degradation, up to 10% at 1.2 GHz and 9% at 0.6 GHz.