According to a custom physical design process for integrated circuits, a method is provided for creating layouts characterized by optimal-length chains for different types of MOS circuit designs, including mixed-signal MOS designs. The body extends along a longitudinal axis between an inlet end and an outlet end with a flow passage extending therebetween. After the completion of the transition, a backlight is switched on to sift to a display-driving mode. The method further comprises storing requesting source characteristic information with the impression data and identifying parameters that require limits on a number of impressions that are to occur in a time period and type of requesting source.