In a System-in-Package (SiP) module, a method and a system for optimizing the timing margin of source-synchronous interface clocks is provided. Clock signals generated by first device are transmitted to serpentine traces located on a Printed Circuit Board (PCB) which adjusts the active edge of one signal relative to another signal. The serpentine trace introduces a delay in the clock signal thereby optimizing timing margins. By providing access to signals otherwise internal the SiP, testing and signal verification is also simplified.