Zycad Corporation

Ampex Systems Corporation

Gatefield Corporation

Actel Corporation, Inc.

Richard D Freeman

John M Caywood

Robert J Lipp

Joseph G Nolan, Iii

Joseph D Linoff

Timothy Saxe

Robert U Broze

A programmable interconnect which closely integrates an independent switching transistor with separate NVM programming and erasing elements. The programming element is an EPROM transistor and the erasing element is a Fowler-Nordheim tunneling device. A unitary floating gate is shared by the switching transistor and the NVM programming and elements which charge and discharge the floating gate. The shared floating gate structure is the memory structure of the integrated programmable interconnect and controls the impedance of the switching transistor.

General purpose, non-volatile reprogrammable switch

The present invention provides for an FPGA integrated circuit having an array of logic cells and interconnect lines interconnected by programmable switches, each formed from a nonvolatile memory cell. The logic cell is designed to provide logic or memory functions according to the setting of programmable switches within the cell. The logic cells in the array are interconnectable by a hierarchy of local, long and global wiring segments. The interconnections are made by the setting of programmable switches between the wiring segments.

Logic cell and routing architecture in a field programmable gate array

A field programmable device includes two separate and electrically isolated arrays of rows and columns of conductors sharing the same area of an integrated circuit substrate, one array interconnecting memory cells to form a random access memory ('RAM'). The other array forms a full or partial cross-point switching network that is controlled by information stored in memory cells, and/or connects to an operating electronic circuit that is configurable and operable in accordance with information stored in memory cells. In addition, the memory array is easily used to access desired nodes of the circuit array in order to be able to easily observe internal signals during operation. A preferred memory structure is a dynamic random access memory ('DRAM') because of a high density and low cost of existing DRAM fabrication techniques, even though periodic reading and refreshing of the states of the memory cells is required. Several circuits and techniques are used which allow continuous assertion of the memory cell states without interruption during the their refreshing cycles.

Random access memory (RAM) based configurable arrays

A keyed, true-transparency combine and keyer receive prioritized image information signals and their corresponding input key signals. On the one hand, others have changed the order of the channels carrying the image signals as the priority of the image signals changes. On the other hand, here we interchange the order of a plurality of substantially identical keyer units within a keyer as the priority of the image signals changes. In interchanging the keyer units, true transparency processed key signals are also generated. In so doing that, the i-th keyer unit modifies the value of its input key signal Bk.sub.i using values of input key signals from higher priority channels. Thereby a true transparency processed key signal Pk.sub.i is generated for the i-th priority channel. In one embodiment, a key-taken signal is generated by multiplying a key-requested signal and a key-available signal while a key-now-available signal is generated by subtracting the key-taken signal from the key-available signal. In another embodiment, a key-taken signal is generated by subtracting a key-now-available signal from a key-available signal while a key-now-available signal is generated by multiplying the key-available signal by one minus the key-requested signal. In either embodiment, the generated key-now-available signal from a higher priority i-th channel is provided to a lower priority (i+1)-st channel as the key-available signal for the lower priority channel and the processed key signal Pk.sub.i is generated in response to the key-taken signal.

Growing community of inventors

San Carlos, CA, United States of America

Richard D Freeman