A 9000-gate user-programmable gate array

The 900-gate XC3090 CMOS user-programmable gate array is the largest member of a family of devices based on a second-generation logic cell array (LCA) architecture. This architecture features three types of user-configurable elements: an interior array of logic blocks, a perimeter of input/output (I/O) blocks, and interconnection resources. Configuration is established by programming internal static memory cells that determine the logic functions and interconnections. An IC design and layout methodology based on modularity combined with the use of advanced processing technology allowed this architecture to be extended to 9000 usable gates. Architectural resources were designed to allow for a range of logic densities without compromising overall performance. User-programmable gate arrays can be used in place of conventional, mask-programmed gate arrays for the majority of digital designs