Various methods and apparatus for electrically probe testing a semiconductor chip with circuit perturbation are disclosed. The composition is particularly well suited for coating the surface of implantable medical device, such as a stent or catheter, in order to permit the device to release bioactive agent to the surrounding tissue over time. Petroleum ore is mixed with a substance comprising mini-dipole susceptors such as carbon strands. Prioritization logic is operable to receive the daisy chain priority signal and to apply predetermined prioritisation criteria to determine the highest priority interrupt request selected from the daisy chain interrupt request and the interrupt request generated by the first plurality of interrupt sources.