Abstract: Each programmable logic device in at least two families of high density segmented programmable array logic device utilizes a programmable switch interconnection matrix to couple an array of symmetric programmable logic blocks. Each programmable logic block includes programmable logic macrocells, programmable input/output macrocells, a logic allocator and a programmable product term array. The programmable switch matrix provides centralized global routing with a fixed path independent delay and decouples the logic macrocells from the product term array. The logic allocator decouples the product term array from the logic macrocells, and the I/O macrocells decouple the logic macrocells from the package I/O pins. The logic allocator steers product terms from the product term array to selected logic macrocells so that no product terms are permanently allocated to a specific logic macrocell.

Abstract: A high density segmented programmable array logic device utilizes a programmable switch interconnection matrix to couple an array of symmetric programmable logic blocks. Each programmable logic block includes programmable logic macrocells, programmable input/output macrocells, a logic allocator and a programmable product term array. Further, the switch matrix provides centralized global routing with a fixed path independent delay. The programmable switch interconnection matrix decouples the logic macrocells from the product term array. The logic allocator decouples the product term array from the logic macrocells, and the I/O marcrocells decouple the logic macrocells from the package I/O pins. Thus, the architecture of this invention is easily scalable to higher density devices without compromising speed. The logic allocator steers product terms from the product term array to selected logic macrocells so that no product terms are permanently allocated to a specific logic macrocell.

Abstract: A high density segmented programmable array logic device utilizes a switch interconnection matrix to couple an array of programmable logic cells. Each programmable logic cell includes programmable input logic macrocells, programmable feedback logic macrocells, programmable output logic macrocells, buried state logic macrocells and an assembly of programmable AND gates and OR gates. Each input macrocell, output macrocell and buried state macrocell has means for generating either a registered/latched output signal or a combinatorial output signal in response to an input signal to the cell. The various switches are used to couple signals to or from the assembly of programmable AND gates and OR gates.