Abstract: A programmable backplane includes a motherboard having slots for receiving printed circuit boards (PCBs). A field programmable interconnect device (FPID) mounted on the motherboard includes a programmable crosspoint switch for selectively routing signals between terminals of the PCBs. The routing is determined by input programming data. The FPID bi-directionally buffers all signals passing between ports of the crosspoint switch and the PCB terminals and can alter signal routing dynamically in response to routing instructions generated by instruction sources mounted on or connected to the PCBs. The programmable backplane may be used as a communication hub in a communication network or parallel processing system.

Abstract: A highly compact nonvolatile solid state memory core is provided that stores and reproduces both digital and analog signals for multimedia applications. The memory core includes vertical electrically erasable and programmable read only memories (EEPROM) cells having, for example, a stacked gate or a split channel configuration. An array of EEPROM cells on the same chip is prewritten and is used as a reference for digital-analog conversions and for memory cell programming. An intelligent write method allows each memory cell to either store an analog signal or multiple digital signals. Based on the previously stored signal, the intelligent write method determines whether to charge or to discharge the floating gate associated with the selected memory cell. Thus, full erasure is not required prior to programming each memory cell. The present invention significantly increases the density of memory cell arrays while prolonging the useful life of the array.

Abstract: A hierarchical crosspoint array is formed by switch cells occupying separate rectangles in a common plane of an integrated circuit. The switch cells are arranged to form square subarrays which, along with a corresponding set of control cells form a compact square shaped crosspoint array. Each switch cell includes three I/O lines crossing in two orthogonal directions and mating with I/O lines of adjacent switch cells to form two orthogonal arrays of I/O lines. Pairs of orthogonal I/O lines are permanently interconnected where they intersect in switch cells along a main diagonal of the array to provide signal paths leading from separate ports along the edges of the array each extending the length and width of the crosspoint array. Each switch cell of a subarray selectively interconnects two such signal paths to provide a signal path between two ports in response to a combination of states of a bit stored in the switch cell and a bit stored in a control cell corresponding to the subarray.

Abstract: A hierarchical crossbar switch includes several switch arrays, each switch array including several switch cells. Each switch cell interconnects a unique pair of signal ports and provides a bi-directional signal path between the signal ports it interconnects when switched on by an enabling signal. A first memory array stores input data indicating particular switch cells to be switched on. A second memory array stores input data indicating particular ones of the switch arrays to be enabled. The crossbar switch also includes a logic cell array that reads the data stored in the first and second memories and sends separate control signals to each switch cell. Each control signal switches on the switch cell to which it is sent when data in the first and second memory arrays indicate both that the switch cell is to be switched on and that the switch cell array including the switch cell is to be enabled.

Abstract: A field programmable interconnect device (FPID) includes a set of ports and an array of switch cells for selectively interconnecting pairs of the ports. The switch cells are organized into a hierarchy of subarrays, and a control cell is provided for each subarray. Each switch cell includes a crosspoint switch and a single-bit memory. A bit stored in the memory indicates whether the switch, when enabled, is to interconnect its pair of FPID I/O ports. A data bit stored in each control cell indicates whether all switching cells of an associated subarray are enabled. In a "rapid connect" mode of operation, the FPID sets the state of the bit stored in any individual switch or control cell in response to parallel input data identifying the cell and indicating the state of the bit to be stored in the cell. In the rapid connect mode, the FPID can be programmed to rapidly switch connections between individual lines or between parallel buses connected to its ports.

Abstract: A highly compact nonvolatile solid state memory core is provided that stores and reproduces both digital and analog signals for multimedia applications. The memory core includes vertical electrically erasable and programmable read only memories (EEPROM) cells having, for example, a stacked gate or a split channel configuration. An array of EEPROM cells on the same chip is prewritten and is used as a reference for digital-analog conversions and for memory cell programming. An intelligent write method allows each memory cell to either store an analog signal or multiple digital signals. Based on the previously stored signal, the intelligent write method determines whether to charge or to discharge the floating gate associated with the selected memory cell. Thus, full erasure is not required prior to programming each memory cell. The present invention significantly increases the density of memory cell arrays while prolonging the useful life of the array.