Synchronous array logic circuit.

摘要

Synchronous array logic circuitry and a system for automatically laying out such circuitry for the fabrication of integrated circuits are described. The synchronous array logic circuitry includes as many cells (10, 20...) as necessary to perform the desired functions with each cell including a transistor array (12) for evaluating a Boolean function and supplying the result to a storage element (18) through a multiplexer (15). The storage element (18) latches the output signal and supplies it to other transistor arrays and/or other cells. The transistor array (12) includes serially connected transistors for performing AND functions and parallel connected transistors for performing OR functions. The multiplexer (15) operates under control of a test signal to configure the storage elements serially, thereby enabling complete testability of all cells (10, 20). Our system includes a method for automatically laying out such circuitry. The method includes steps of arranging the storage elements (18) in a desired order, assigning transistors within a given cell to positions along a first axis, assigning transistors within the cell to a position along a perpendicular axis, and laying out an interconnecting diffusion path. Once all cells are specified, the cells may be interconnected in a desired manner.