Advanced Micro Devices Corporation

Lattice Semiconductor Corporation

Nicholas A Schmitz

Om P Agrawal

Bradley A Sharpe-Geisler

Jerry D Moench

Kerry A Ilgenstein

George H Landers

Bryon I Moyer

John David Porter

Jeffery Mark Marshall

Benjamin Howard Ashmore, Jr

A programmable optimized-distribution logic allocator enhances the speed, silicon utilization, logic efficiency, logic utilization, and scalability of very high-density CPLDs including the logic allocator. The programmable optimized-distribution logic allocator provides an optimized number of product terms to each I/O pin of the CPLDS and the same uniform number of product terms as feedback. However, no product terms are permanently connected to either a particular macrocell or a particular I/O pin. The programmable optimized-distribution logic allocator includes a multiplicity of router elements where each router element steers a sum of a selected number of sum-of-product terms from a PAL structure, i.e, a selected number of logic product-term clusters, to a programmably selected logic macrocell. Specifically, the programmable optimized-distribution logic allocator has a plurality of input lines, a plurality of output lines and a plurality of programmable router elements. Each programmable router element has an input terminal connected an input line in the plurality of input lines and an output terminal connected to an output line in the plurality of output lines.

Programmable optimized-distribution logic allocator for a high-density complex PLD

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. In a first PLD of each family, a first predetermined number of input lines couple the switch matrix to each programmable logic block. In a second PLD of each family, a second predetermined number of input lines couple the switch matrix to each programmable logic block. The number of input lines to each programmable logic block and to the switch matrix are selected to provide a predetermined routability factor. The second family of PLDs has a larger pin to logic ratio than the first family of PLDs.

High density programmable logic device

A block clock and initialization circuit for a programmable logic block in a complex very high density programmable logic device generates a plurality of block clock signals and block initialization signals for elements in the programmable logic block. The block clock and initialization circuit includes a block clock generator circuit and a block initialization circuit. The block clock generator circuit receives a first set of product terms in a plurality of product terms and a plurality of clock signals as input signals. In response to the input signals, the block clock generator circuit generates output signals on a plurality of block clock lines. The block initialization circuit receives a second set of product terms in the plurality of product terms as input signals. In response to the input signals, the block initialization circuit generates a plurality of output signals on the block initialization lines.

Block clock and initialization circuit for a complex high density PLD

A very high-density complex programmable logic device (CPLD) has a plurality of hierarchical signal paths. The lowest level of the hierarchy is independent from all higher levels. Similarly, an intermediate level is independent from all higher levels and utilizes only resources of the CPLD associated with the lowest and intermediate hierarchical levels. The first hierarchical level resources include a programmable logic block having a plurality of input lines and a plurality of output lines, and a programmable block switch matrix connected to the plurality of input lines of the programmable logic block. The second hierarchical level resources include a programmable segment switch matrix connected to a plurality of input lines of the programmable block switch matrix. The CPLD in addition includes a third hierarchical level circuit having third hierarchial level resources connected to the second hierarchical level resources where a third hierarchical level signal path utilizes the third, second, and first hierarchical level resources. The third hierarchical level resources include a programmable global switch matrix having global switch matrix lines programmably connected to and disconnected from lines of the programmable segment switch matrix.

Very high-density complex programmable logic devices with a multi-tiered

Family of multiple segmented programmable logic blocks interconnected by

Programmable logic device design software is provided for allocating specific resources in a programmable logic device having a multiplicity of programmable logic blocks interconnected by a programmable switch matrix to logic equations in a user logic design. In particular, a resource allocation means for fitting a logic design to a multiplicity of programmable logic blocks with limited interconnectivity between the modules is provided. The resource allocation means requires minimal programmable logic device resources to achieve the allocation of resources within the programmable logic device to the user logic design. The resource allocation means employs block partitioning means and resource assignment means to map user logic to a programmable logic device (PLD) having multiple programmable AND fixed OR arrays interconnected by a programmable switch matrix, i.e., allocate the PLD resources to the user logic.

Apparatus and method for allocation of resoures in programmable logic

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.

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Sunnyvale, CA, United States of America

Nicholas A Schmitz