XC3090L-Series Field Programmable Gate Arrays (FPGAs) provide a group of high-performance, high-density, digital integrated circuits. Their regular, extendable, flexible, user-programmable array architecture is composed of a configuration program store plus three types of configurable elements: a perimeter of I/O Blocks (IOBs), a core array of Configurable Logic Bocks (CLBs) and resources for interconnection. The development system provides schematic capture and auto place-and-route for design entry. Logic and timing simulation, and in-circuit emulation are available as design verification alternatives. The design editor is used for interactive design optimization, and to compile the data pattern that represents the configuration program.