A Robust Architecture for Post-Silicon Skew Tuning

Clock skew minimization is important in VLSI design field. Due to the presence of Process, Voltage, and Temperature (PVT) variations, the Post-Silicon Skew Tuning (PST) technique with the ability of tolerating PVT variations has brought a broad discussion. A PST architecture can dynamically minimize the clock skew even after a chip is manufactured. However, testing the variation tolerance ability of a PST architecture is very difficult because the clock skew does not directly affect the functionality of a design. In addition, creating PVT variation in the traditional testing environment is not easy. Unlike most previous works which focus on the implementation and the performance issues of a PST architecture, the objective of this paper is to propose efficient test mechanisms and verify the variation tolerance ability. In addition, we also propose a novel structure to increase the robustness of a PST architecture in case of a manufacturing fault. Our experiment shows that with little overhead, we can achieve robustness.