An efficient algorithm of adjustable delay buffer insertion for clock skew minimization in multiple dynamic supply voltage designs

Power consumption is known to be a crucial issue in current IC designs. To tackle this problem, multiple dynamic supply voltage (MDSV) designs are proposed as an efficient solution in modern IC designs. However, the increasing variability of clock skew during the switching of power modes leads to an increase in the complication of clock skew reduction in MDSV designs. In this paper, we propose a tunable clock tree structure by adopting the adjustable delay buffers (ADBs). The ADBs can be used to produce additional delays, hence the clock latencies and skew become tunable in a clock tree. Importing a buffered clock tree, the ADBs with delay value assignments are inserted to reduce clock skew in MDSV designs. An efficient algorithm of ADB insertion for the minimization of clock skew, area, and runtime in MDSV designs has been presented. Comparing with the state-of-the-art algorithm, experimental results show maximum 42.40% area overhead improvement and 117.84× runtime speedup.