Abstract: The present invention relates to a system and method for using a place and route CAD tool for locating scan elements within a functional block of an integrated circuit (IC) in proximity to a clock trunk line to enable efficient transmission of scan data out of the IC for diagnostic purposes. A scan enable signal is preferably directed in a direction opposite the direction of scan data propagation to ensure that a scan element in a scan chain is emptied of its data before new data is written to that element. This process of reverse scan enable signal propagation direction is preferably practiced for all elements in the scan chain. The inventive approach preferably enables automated design to be employed in the placement and routing of the scan elements while still preventing race conditions, thereby enabling a single clock to be employed for the scan chain.