An integrated search engine device evaluates span prefix masks for keys residing at leaf parent levels of a search tree to identify a longest prefix match to an applied search key. In various embodiments of the invention, diode-connected transistors can be identified in a circuit netlist based on the unique structure. Also disclosed are methods of making and using the expression vectors. In response to program calls to file system routines that reference files associated with resources of the PLD, the virtual file system is invoked, and the virtual file system accesses state information in resources of the PLD. The single junction type CIGS thin film solar cell includes a substrate, a back contact deposited on the substrate, a light absorption layer deposited on the back contact and including a P type CIGS layer and an N type CIGS layer coupled to the P type CIGS layer using a single junction, and a reflection prevention film deposited on the light absorption layer. Thereby, no correspondence point needs to be given, no special tool or object is used, and all points on the image are used, so that an internal parameter can automatically be obtained with high precision, and image lens distortion can be corrected with high precision.