Clock skew minimization has been an important design constraint. However, due to the complexity of Process, Voltage, and Temperature (PVT) variations, the minimization of clock skew has faced a great challenge. To overcome the influence of PVT variations, several previous works proposed Post Silicon Tuning (PST) architecture to dynamically balance the skew of a clock tree. In the PST architecture, there are two main components: Adjustable Delay Buffer (ADB) and Phase Detector (PD). Most previous works focus on determining good positions of ADBs in a PST design. In this paper, we first show that which pairs of FFs are connected to PDs, called PD structure, also greatly influence the complexity of hardware control for a PST design. Without careful planning of a PD structure, we need large number of control signals to adjust the delays of ADBs. In addition, we also show that a PD structure may influence the accuracy of the clock skew. Among possible connection structures, this paper prop...