Abstract: A mechanism for verifying system behavior includes: (1) A “constraint-based inference engine” and (2) a “constraint-based simulator.” The inference engine accepts logical/temporal/data dependencies describing a system implementation and automatically derives new logical/temporal/data dependencies describing the input/output (“black-box”) behavior of the system or other aspect of the system's behavior. This capability means that a “behavioral model” can be automatically extracted from a “structural model,” thereby. supporting “encapsulation” and “information hiding.

Abstract: A low transistor count programmable bussing resource for a programmable logic array allows the use of the bussing resources as inputs or outputs to a cell in the array and allows connections between different buses without effecting the normal use of the cell. The bussing resource allows efficient routing of signals between cells and is symmetric to allow rotation of logic macros built using combinations of cells and buses.

Abstract: The present invention provides a configurable logic array that includes a plurality of individually configurable logic cells arranged in a matrix that includes a plurality of horizontal rows of logic cells and a plurality of vertical columns of logic cells. Adjacent abutting cells logic cells are interconnectable via horizontal and vertical configurable interconnections running between adjacent cells. Furthermore, configurable diagonal interconnections run between diagonally adjacent abutting logic cells in the array.