Abstract: A complex programmable logic device (PLD) that includes a number of programmable function blocks and an instruction bus for receiving programming instructions. The programming instructions are used to program the function blocks to enable the PLD to perform one or more desired logic functions. The PLD also includes an instruction-blocking circuit that is connected to each of the functional blocks. When directed by a user, the instruction blocking circuit selectively blocks programming instructions on the instruction bus from one or more of the function blocks while allowing the other function blocks to receive the programming instructions. Thus, one or more function blocks in the PLD are reprogrammed without interrupting the operation of the remaining function blocks.

Abstract: In a programmable logic device having a plurality of external pins each of which may be driven by an output drive structure controlled by a programmable logic block, a logic device such as an OR gate or a programmable pull-up or pull-down switch is inserted between the input terminal of the output drive structure and the programmable logic block or other internal logic block which controls the output driver. This inserted structure allows the macrocell to be used for internal logic while the output drive structure is used to stabilize power or ground voltage.

Abstract: A memory device, with increased storage speed and enhanced memory utilization, can be implemented by using multiplex clocking and efficient device design and enhanced flip-flop utilization. Transit time through the circuit, and hence circuit speed, can be controlled through multiplexed clock signals, and is increased by using fewer transistors in the signal path and allowing data to be transmitted directly to the flip-flop output by bypassing the flip-flop's master latch input.

Abstract: A programmable logic device having macrocells enables gate cascades between macrocells to occur with a faster signal transit time, while preserving the flip flop function of the cascaded macrocells by reallocating a redirectable flip flop reset product term to the flip flop input. All gate product terms are retained during cascading. The macrocell logic is optimized for fast signal transit with selectable flip flop clocking. Multiplex clocking and programming are done with fewer transistors in the signal path, further reducing signal transit time.

Abstract: An erasable programmable logic device (EPLD) includes function blocks connected by a universal interconnect matrix (UIM). The UIM includes both a cross-point circuit and a multiplexer-based (MUX-based) circuit. The cross-point circuit includes intersecting first and second conductors programmably connected by memory cells having control gates connected to the first conductors, drains connected to the second conductors, and sources connected to ground. The MUX-based circuit includes third and fourth conductors programmably connected by pass-gates having first terminals connected to the third conductors, second terminals connected to the fourth conductors, and gates connected to memory cells. The UIM further includes multiple-input multiplexers having first input lines connected to the cross-point circuit, second input lines connected to the MUX-based circuit, and output lines connected to the input lines of the function blocks.

Abstract: The present invention provides a sense circuit including a first bit line, a second bit line, a first plurality of memory cells coupled to the first bit line, a second plurality of memory cells coupled to the second bit line, and selection circuitry coupled to the first bit line and the second bit line. The selection circuitry provides a wide AND gate function in one mode and provides a zero power circuit for generating a function of a single input in another mode.

Abstract: A programmable logic device having macrocells enables gate cascades between macrocells to occur with a faster signal transit time, while preserving the flip flop function of the cascaded macrocells by reallocating a redirectable flip flop reset product term to the flip flop input. All gate product terms are retained during cascading. The macrocell logic is optimized for fast signal transit with selectable flip flop clocking. Multiplex clocking and programming are done with fewer transistors in the signal path, further reducing signal transit time.